Feasibility Report On
Ligno-cellulosic Biomass to 2G Ethanol,
Mangalore Refinery & Petrochemicals Ltd
Document No. B033-000-03-41-RP-01
June 2017
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CONTENTS
1. EXECUTIVE SUMMARY
1.1
Introduction
8
1.2
Background for Feasibility Study Report
8
1.3
EOI Received
9
1.4
Basic Study Parameters
1.5
1.4.1
Ethanol plant capacity
9
1.4.2
Objective of Study
10
1.4.3
Product Specification
10
1.4.4
Feed Specification
11
Technology Assessment
12
1.5.1
Lignocellulosic Biomass
11
1.5.2
Process for Ethanol Generation from
12
Lignocellulosic Biomass
1.5.3
EOI’s Information & Technical Review
14
1.5.3.1
Technology – A
14
1.5.3.2
Technology – B
16
1.5.3.3
Technology – C
17
1.5.3.4
Technology – D
17
1.5.4
Technology Analysis
25
1.5.5
Areas of technology requiring detailed assessment
27
1.6
Capital Cost Estimation
28
1.7
Environment Impact
30
1.8
Project Schedule
31
1.9
Preliminary Plot Plan
31
1.10
Social Benefit
31
1.11
Way Forward
31
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2. INTRODUCTION
2.0
Introduction
33
3. SCOPE OF WORK
3.0
Scope of Work
36
4. DESIGN BASIS OF STUDY
4.1
Ethanol plant capacity
38
4.2
Product Specification
38
4.3
Feed Specification
38
5. PROJECT DESCRIPTION
5.1
Technology Licensors
42
5.2
Material Balance
42
5.3
Utilities & Off-site Facilities
45
6. TECHNOLOGY ASSESSMENT
6.1
Understanding of Ligno-cellulosic Biomass
47
6.1.1
Cellulose
48
6.1.2
Hemicelluloses
48
6.1.3
Lignin
48
6.2
Processes for Ethanol Generation from Lignocellulosic Biomass
49
6.3
Process Description for Bio-Ethanol Production
50
6.4
6.3.1
Pretreatment
51
6.3.2
Hydrolysis
53
6.3.3
Fermentation
53
6.3.4
Distillation and Purification
54
Technology Assessment
6.4.1
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54
Technology A
55
6.4.1.1
Material Handling & Wet Washing Section 56
6.4.1.2
Main Process Plant
57
6.4.1.3
Utilities & Auxiliaries
59
6.4.1.4
Residue Handling Section
61
6.4.1.5
Add On Packages
62
6.4.1.6
Overall Material and water Balance of
65
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Plant
6.4.1.7
6.4.2
6.4.3
6.4.4
6.5
Features
67
Technology B
68
6.4.2.1
Process Description
68
6.4.2.2
Byproducts and Effluents
71
6.4.2.3
Overall Material Balance of Plant
73
6.4.2.4
Waste Water Treatment
74
6.4.2.5
Features
75
Technology C
75
6.4.3.1
Process Description
75
6.4.3.2
Features
78
Technology D
78
6.4.4.1
Process Description
79
6.4.4.2
Outflow Streams from the Process Plant
81
6.4.4.3
Overall Material Balance of Plant
82
6.4.4.4
Features
83
Technology Analysis
6.5.1
88
Areas of technology requiring detailed assessment
90
7. UTILITIES AND OFFSITES
7.1
7.2
Utilities
7.1.1
Raw water system
92
7.1.2
Cooling water system
93
7.1.3
DM water and Soft water system
93
7.1.4
Compressed air system
93
7.1.5
Steam, power and BFW system
93
Offsite facilities
7.2.1
7.3
92
94
Storage and Transfer System
94
Flare Systems
95
8. PROJECT SCHEDULE & PROJECT EXECUTION METHODOLOGY
9. ENVIRONMENT CONSIDERATIONS
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9.1
Environmental Considerations
10. PROJECT COST ESTIMATION
10.0
Cost Estimation
11. PRELIMINARY PLOT PLAN
11.1
Plot Plan
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99
104
108
12. WAY FORWARD
12.1
Way Forward
110
ANNEXURES
Annexure I: CAPITAL COST ESTIMATION
Annexure II: PROJECT SCHEDULE & PROJECT IMPLEMENTATION METHODOLOGY
Annexure III: PRELIMINARY PLOT PLAN
Annexure IV: FEED ANALYSIS
Annexure V: LICENSOR SUPPLIED INPUTS FOR COST ESTIMATION (TECHNOLOGY B)
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List of Figures
Fig. No.
Title
Page No.
1.1
Over all material balance for Technology – A.
15
1.2
Over all material balance for Technology-B
16
1.3
Over all material balance for Technology-D
18
6.1
Schematic diagram of plant cell walls
47
6.2
Schematic diagram of Plant Component
48
6.3
Technologies for Ethanol Generation from Lignocellulosic Biomass
49
6.4
Technological routes for Ethanol Generation from
50
Lignocellulosic Biomass
6.5
Schematics of biomass to bio-ethanol technology
51
6.6
Process diagram of Technology A
57
6.7
Over all material balance of Technology A
66
6.8
Process schematic for Technology B
69
6.9
Simplified scheme of byproduct and effluent streams of Technology B
72
6.10
Over all material balance of Technology B
73
6.11
Typical stillage / waste water treatments configuration
74
6.12
Schematic diagram for Technology D
76
6.13
Flow diagram for Technology D
77
6.14
Technology D outline
79
6.15
Over all material balance of Technology D
83
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List of Tables
Table No.
1.1
Title
Page No.
Ethanol requirement in future for 5%, 10% and 20% blending
9
in petrol (In Million Lt.)
1.2
Product specification for fuel grade ethanol
10
1.3
Typical composition of some ligno-cellulosic bio-mass residues
11
1.4
Composition of feedstock
12
1.5
Technology comparison
20
1.6
Cost of feed, product and utilities
28
1.7
Cost estimate for biomass to Ethanol Complex (power Import)
30
1.8
Cost estimate for biomass to Ethanol Complex (power generation)
30
4.1
Product specification for fuel grade ethanol
38
4.2
Typical composition of some ligno-cellulosic bio-mass residues
39
4.3
Composition of feedstock
39
4.4
Price of Feed, Product and utilities
40
5.1
Material balance for Technology A
43
5.2
Material balance for Technology B
44
5.3
Material balance for Technology D
44
6.1
Comparison of the different pretreatment processes
52
6.2
Comparison of different options for 2nd stage hydrolysis
53
6.3
List of the processes in ISBL
68
6.4
Comparison of technology
85
7.1
Summary of estimated utility requirement
92
7.2
Storage details
94
7.3
By product details for 100 KLPD ethanol plant
95
9.1
Standards for Emissions from Boilers Using Agriculture Waste As Fuel
100
9.2
National ambient air quality standards
101
10.1
Cost of feed, product and utilities
104
10.2
Cost estimate for biomass to Ethanol Complex (power Import)
106
10.3
Cost estimate for biomass to Ethanol Complex (power generation)
106
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SECTION - 1
EXECUTIVE SUMMARY
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1.1 Introduction
MRPL is examining the feasibility of setting up a Ligno-cellulosic ethanol production plant to
produce 60 KL per day of 2G ethanol using domestic agro based lignocellulosic feedstock in
Karnataka state. MRPL has published Expression of interest (EOI) to identify Licensors/
technology providers (called as “Bidders”) with requisite competence, experience,
infrastructure & finance, for setting up and operation and maintenance of Ligno-Cellulosic
Ethanol production Plant in Karnataka state, India in collaboration with MRPL by using
domestic surplus Agri based lignocellulosic feedstock. EIL has been selected to prepare a Prefeasibility study report (PFR) on ligno-cellulosic biomass to 2G-ethanol including the capital
cost estimation for select technologies based on the responses received for the EOI from the
bidders.
To ascertain the feedstock availability in Karnataka, MRPL engaged M/s PRESPL for carrying
out the Biomass assessment study and Indian Institute of Science for validating the study. The
plant capacity (net surplus bio mass availability after meeting fodder requirements) and the type
of feed stock has been derived based on this study.
1.2 Background for Pre-Feasibility Study Report
Bio-fuels are lucrative alternative energy option as they are clean and have low sulfur content
thereby having positive environmental impact. Therefore need of the hour is development of
second generation biofuels using surplus agricultural residues and waste that can be harnessed
as ligno-cellulosic bio-fuel source. Same is clearly embodied in the National Bio fuel policy
(NBP) 2009.
The main reasons for the enhanced development of bio-ethanol are its use as a favorable and
near carbon neutral renewable fuel, thus reducing CO2 emissions and associated climate change.
Whether first, second, or third generation feedstock is used, fermentation produces an alcohollean broth only, as such unusable in industrial and fuel applications. The ethanol must hence be
purified. Fractional distillation can concentrate ethanol to 95.6 vol% (89.5mol %),
corresponding to the azeotropic composition with a boiling point of 78.2∘C. Remaining moisture
is captured in dehydration column to produce anhydrous fuel grade ethanol.
The practice of blending ethanol started in India in 2001. Government of India mandated
blending of 5% ethanol with petrol in 9 States and 4 Union Territories in the year 2003 and
subsequently mandated 5% blending of ethanol with petrol on an all-India basis in November
2006 (in 20 States and 8 Union Territories except a few North East states and Jammu &
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Feasibility Report on
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2G Ethanol, MRPL
Kashmir). Ministry of Petroleum and Natural Gas, on 1 September, 2015, has asked OMCs to
target 10% blending of ethanol in petrol in as many States as possible. Table 1.1 shows the
ethanol requirement in future for 5%, 10% and 20% blending in petrol.
Table 1.1: Ethanol requirement for 5%, 10% and 20% blending (In Million Lt.)
Particulars
2016-17
2017-18
2018-19
2019-20
2020-21
2021-22
Petrol Sale
Projection
(14 % CAGR)
29027
33091
37723
43005
49025
55889
Ethanol Requirement
(@ 5% blending)
1451
1655
1886
2150
2451
2794
(@ 10% blending)
2903
3309
3772
4300
4903
5589
(@ 20% blending)
5805
6618
7545
8601
9805
11178
Petroleum Planning & Analysis Cell (PPAC)
1.3 EOI Received
The following Technology Licensor parties had responded for the EOI’s raised by MRPL:
 M/s Praj Industries Limited
2. M/s Beta Renewables S.p.A
3. M/s Renmatix, Inc.
4. DBT – ICT
1.4 Basic Study Parameters
1.4.1 Ethanol plant capacity
The feasibility study is carried out for 60 kilo litres per day (KLPD) of bio ethanol plant from
lignocellulosic biomass. Though the EOI received from various licensors was for 100 KLPD,
the plant capacity has been fixed at 60 KLPD based on the biomass assessment study as both
the activities were carried out in parallel. The technology comparison of various licensors has
been carried out based on 100 KLPD plant capacity. Cost estimation however has been carried
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out for 60 KLPD plant capacity based on the revised inputs received from the licensors as well
as in-house inputs. Relevant data as necessary has been provided by the licensors.
1.4.2 Objective of Study
The objective of the feasibility study is the technology assessment of all licensors based on
offers received for 100 KLPD plant and cost estimation with ± 30% accuracy for the licensor
who have provided relevant data for a 60 KLPD plant. The preliminary plot plan (table top) as
well as the project schedule with project execution methodology is also envisaged as the
objective.
1.4.3 Product Specification:
The quality and standard as per Indian specifications (IS15464:2004) of anhydrous ethanol for
use in automotive fuel is as listed below.
Table 1.2: Product specification for fuel grade ethanol
S. No
Parameters
Value
1
Relative density at 15.6/15.6 °C, Max
0.7961
2
Flash point
16.6 oC
3
Ethanol content percent by volume at
15.6/15.6°C Min. (excluding denaturant)
4
Miscibility with water
5
Alkalinity
Nil
6
Acidity (as CH3COOH) mg/l, Max
30
7
Residue on evaporation percent by mass, Max
8
Aldehyde content (CH3CHO) mg/l, Max
60
9
Copper, mg/kg, Max
0.1
10
Conductivity µS/m, Max
300
11
Methyl alcohol, mg/litre, Max
300
12
Appearance
Format No. EIL 1641-1924 Rev. 1
99.50
Miscible
0.005
Clear and bright
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1.4.4 Feed Specification
Ethanol plant should be feed stock flexible. It should be able to process different biomass like
rice straw, wheat straw, cotton stalk, sugarcane bagasse etc. as feedstock. Typical composition
of some ligno-cellulosic bio-mass residue is given below in Table 1.3.
Table 1.3: Typical composition of some ligno-cellulosic bio-mass residues
Feedstock
Cellulose
(%)
Other
Hemicellulose (%)
Lignin (%)
(Moisture, silica,
ash etc)
Bagasse
42
25
20
13
Corn stover
38
26
19
17
Corncob
45
35
15
5
Rice Straw
32
24
18
26
Rice Husk
36
20
20
24
Wheat straw
35
32
21
12
Sweet sorghum
45
27
21
7
Nut Shell
30
30
30
10
Maize Straw
36
28
29
7
Cotton Straw
42
12
15
31
Switch grass
40
30
12
18
Hardwood
40
40
18
2
Pine
44
26
29
1
The biomass assessment study carried out by M/s PRESPL concluded the following:

The net surplus biomass available is only adequate for setting up a 60 KLPD 2G ethanol
plant.

Maize/Corn cobs as the primary feed stock and rice straw as alternate feed stock.
The composition of the feedstock is provided in the table.
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Table 1.4: Composition of feed stock
Feedstock
Cellulose
Hemicellulose
Lignin
Ash
Moisture
Silica
Others
wt%
wt%
wt%
wt%
wt%
wt%
wt%
Corn Cob
33-34
27-28
18-19
2-3
9-10
0.5-1
3-4
Rice Straw
31-32
16-17
16-17
12-16
9-15
6-8
15-17
Refer Annexure IV for detailed analysis of feed.
1.5 Technology Assessment
1.5.1 Ligno-cellulosic Biomass
Understanding ligno-cellulosic biomass, particularly its chemical composition, is a prerequisite
for developing effective pretreatment technologies to deconstruct its rigid structure, designing
enzymes to liberate sugars, particularly cellulose to release glucose, from recalcitrant cellulose,
as well as engineering microorganisms to convert sugars into ethanol and other bio-based
chemicals. Lignocellulosic biomass is mainly composed of plant cell walls, with the structural
carbohydrates cellulose and hemi-cellulose and heterogeneous phenolic polymer lignin as its
primary components.
Cellulose is a polysaccharide composed of linear glucan chains which are held together by intramolecular hydrogen bonds as well as intermolecular van-der Waals forces. The crystalline
cellulose must be subjected to some preliminary chemical or mechanical degradation before it
can be broken down into glucose.
Hemicellulose consists of short, highly branched chains of sugars. It contains pentoses,
hemicelluloses chains are more easily broken down to form their simple monomeric sugars than
is cellulose because of their highly amorphous and branched structure. The exact sugar
composition of hemicelluloses can vary depending on the type of plant.
Lignin is a non-sugar-based polymer and cannot be used as feedstock for ethanol production via
microbial fermentation. It exerts a significant impact on the economic performance of the
corresponding bioconversion processes, since most inhibitors of microbial growth and
fermentation. As the second most abundant component in biomass after cellulose, lignin yields
more energy when burned, and thus is a good selection for combined heat and power production
in an eco- and environment-friendly mode of the bio-refinery.
1.5.2 Process for Ethanol Generation from Lignocellulosic Biomass
Typically biochemical conversion process is carried out in four stages
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1. Physical or chemical pretreatment of the plant fibers to expose the cellulose and reduce
its crystallinity,
2. Hydrolysis of the cellulose polymer, with enzymes or acids, to convert it into simple
sugars (glucose),
3. Microbial fermentation of these simple sugars to ethanol and
4. Distillation and dehydration to produce 99.5% pure alcohol.
Pretreatment:
The pretreatment process converts most of the hemicellulose carbohydrates in the feedstock to
soluble sugars (xylose, mannose, arabinose and glucose) by hydrolysis reactions. Acetyl groups
in the hemicellulose are liberated as acetic acid. The breakdown of biomass in pretreatment
facilitates downstream enzymatic hydrolysis by disrupting cell wall structures, driving some
lignin into solution, and reducing cellulose crystallinity and chain length. The nature and extent
of such changes are highly dependent on the pretreatment chemistry and reaction severity
(defined by residence time, temperature, and catalyst loading).
Hydrolysis:
Hydrolysis process generates fermentable monomeric sugars from hemicellulose and cellulose
content of lignocellulosic biomass. This can be accomplished by two different processes,
namely,
1. Acid hydrolysis
2. Enzymatic hydrolysis.
In acid hydrolysis, mineral acids such as sulfuric acid, hydrochloric acid, hydrofluoric acid and
nitric acid are widely employed for the hydrolysis of lignocellulosic biomass.
In enzymatic hydrolysis step cellulose is converted to glucose using cellulase enzymes. This
process is known as enzymatic saccharification or enzymatic hydrolysis. A cellulase enzyme
preparation is a mixture of enzymes (catalytic proteins) that work together to break down
cellulose fibers into cellobiose and soluble gluco-oligomers and ultimately into glucose
monomers. The resulting glucose and other sugars hydrolyzed from hemicellulose during
pretreatment are co-fermented to ethanol.
For higher conversion and lower metallurgy enzymatic hydrolysis is favorable over acid
hydrolysis.
Fermentation:
Fermentation is the biological process to convert the hexoses and pentoses into ethanol by a
variety of microorganisms, such as bacteria, yeast, or fungi.
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When using enzymatic hydrolysis, different integration methods of hydrolysis and fermentation
steps are proposed. These are separate hydrolysis and fermentation (SHF), separate hydrolysis
and co-fermentation (SHCF) and simultaneous saccharification and co-fermentation (SSCF) are
other possible alternatives.
Distillation and Purification:
From fermented mash, fuel grade ethanol is produced through distillation and adsorption via
molecular sieve. Desired separation specification of 99.5%vol ethanol cannot be achieved by
distillation alone because of the non-ideal solution behavior of the water-ethanol mixture. An
azeotrope is observed when the mixture reaches 95.5% mole purity of ethanol. 95.5 % alcohol
is passed through molecular sieve to produce fuel grade ethanol.
1.5.3 EOI’s Information & Technical Review
The EOIs response received from various technology licensors for the 2G ethanol production
from ligno cellulosic biomass are reviewed. The comparison of all technology licensors have
done based on 100 KLPD Plant capacity.
1.5.3.1 Technology – A
Overall material balance: As per information available from technology provider the overall
material balance is given below for various feedstock provided by them.
A) Feed: Bagasse
ISBL
OSBL
Mill Loss = 7.6 TPD
TPD
CO2 = 137.74 TPD
FO$= 0.25 TPD
Fuel
Grade
Ethanol
Plant
Bagasse = 385 TPD
Chemical*
Enzyme =3.73 TPD
TA# = 1.7 TPD
Lignin = 155 TPD
BioCNG = 40.2 TPD
TPD
Rejects = 17.74 TPD
Yeast = 0.03 TPD
Sulphur = 4.2 TPD
EtOH = 80 TPD
*Chemicals:
Mixed Acid
Molasses
: 9.63 TPD
: 21.17 TPD
Format No. EIL 1641-1924 Rev. 1
Nutrients
Other Chemicals
: 5.05 TPD
: 19.25 TPD
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B) Feed: Rice Straw
ISBL
OSBL
CO2 = 130.5 TPD
Rice
Straw = 421 TPD
FO$ = 0.26 TPD
Fuel
Grade
Ethanol
Plant
Chemical*
Enzyme =3.70 TPD
TA# = 1.7 TPD
Lignin = 199.8 TPD
Rejects = 16.4 TPD
Yeast = 0.03 TPD
Millings &
Conv. Loss = 3.8 TPD
BioCNG = 37.7 TPD
EtOH = 79.44 TPD
* Chemicals:
Mixed Acid
Molasses
#
: 12.78 TPD
: 17.04 TPD
TA = Technical Alcohol
Nutrients
Other Chemicals
$
Sulphur = 3.8 TPD
: 4.26 TPD
: 19.17 TPD
FO = Fusel Oil
Fig. 1.1: Over all material balance for Technology – A
Features:

Developed indigenous 2G Ethanol technology in 2009

Bio-ethanol % conversion for per ton of dry biomass is of rice straw and bagasse is
19% and 21 % respectively.

Process can be operated with multiple feedstocks (such as rice straw, bagasse, cotton
straw, wheat straw etc.) but not with mixed feed.

Feed size for the process is 25-40 mm.

Major byproducts from technology A are Bio-CNG (9%), Liquefied CO2 (10.5%),
Technical Alcohol (4%), Fusel Oil (0.6%), Lignin (47%)

Enzyme and yeast consumption for per ton of dry biomass conversion is 8.7 kg and 0.7
kg respectively.

Total conversion time from biomass to bio ethanol is 100-120 hour.

Approximately 100% water re-cycle via effluent treatment plant in ISBL. However,
some water effluent is there from utilities.
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Feasibility Report on
Ligno-Cellulosic Biomass to
2G Ethanol, MRPL

Lignin rich cake is separated from solid liquid separation & used as a boiler fuel along
with primary fuel.

Turndown capacity for the proposed plant of capacity 100 KLPD is about 70 % of
maximum capacity

Licensor has Experience on 1st generation ethanol production technology as a global
equipment supplier.

Licensor has strength to provide fully integrated end to end scheme for bio-ethanol
plant including OSBL.
1.5.3.2 Technology – B
Overall material balance: As per information available from technology provider the overall
material balance is given below.
ISBL
OSBL
Vent = 504 TPD
Fuel
Grade
Ethanol
Plant
Biomass= 477.6 TPD
Chemical*
Enzyme = 6 TPD
Misc. 2155 TPD
Lignin = 386.4 TPD
Conc. Stil = 331.2 TPD
Waste = 13.68 TPD
Trash & Dust = 6 TPD
FO = 0.96 TPD
MP cond.: 518 TPD
Effluent: 806.5 TPD
Yeast = 0.0624 TPD
EtOH = 78.72 TPD
* Chemicals:
Antifoam
Urea
: 0.0792 TPD
: 1.97 TPD
Sodium Hydroxide (100%)
: 4.8 TPD
Misc.
Propagation Media: 165.6 TPD; Air: 434.4 TPD ; Steam: 969.6 TPD; Process Water : 585.6 TPD
Fig. 1.2: Over all material balance for Technology B
Features:

Commercial Scale Bio Ethanol plant has started in 2013.

Bio-ethanol % conversion for per ton of dry biomass is almost 16.5%.
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Ligno-Cellulosic Biomass to
2G Ethanol, MRPL

DOCUMENT No.
B033-000-03-41-RP-01
Rev. 1
Page 17 of 111
Process can be operated with multiple feedstocks (such as rice straw, bagasse, cotton
straw, wheat straw etc.) but not with mixed feed.

Major byproducts are Liquefied CO2, Concentrated stillage and surplus power.

Claim unique steam explosion process as pretreatment of biomass.

Total conversion time from biomass to bio ethanol is 120 hour.

Lignin and concentrated stillage can be sold for off-site uses in energy generation or
cogeneration facility can be set up on clients’ requirements.

A 2G ethanol technology with experience and learning at commercial scale

470,000 TPA (Dry Biomass) started in September- 2014.

Sustained supply of enzymes with equity partner.

No fine size reduction is required.
 Technology – C
Features:

Has novel technology based on Supercritical hydrolysis of water.

Super-critical reactor has modular design, i.e. reactor capacity can be increased or
decreased by joining or removing extra reactor tubes.

Bio-ethanol % conversion for per ton of dry biomass is 24.4 %.

Total conversion time from biomass to bio ethanol is 12-24 hours.

The technology produces soluble sugars which can be directly fermented.

No requirement of enzyme for this process.

Time for biomass conversion to sugars: 2-90 minutes

Low reactor volumes

Backed by global companies.
1.5.3.5 Technology – D
Overall material balance: As per information available from technology provider the overall
material balance for two feeds (Bagasse and Rice Straw) are given below.
A) Feed : Bagasse
Format No. EIL 1641-1924 Rev. 1
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Feasibility Report on
Ligno-Cellulosic Biomass to
2G Ethanol, MRPL
ISBL
OSBL
CO2 = 195 TPD
Fuel Grade
Ethanol
Plant
Bagasse = 324 TPD
Chemical*
Enzyme =1 TPD
DOCUMENT No.
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Page 18 of 111
FO$ = 0.4 TPD
Waste = 16.5 TPD
Dusting = 2 TPD
Bio CNG = 41 TPD
Yeast = NA
EtOH = 80 TPD
* Chemicals:
Nitric Acid (100%)
Others Salts
: 3.8 TPD
: 1.7 TPD
NaOH (100%)
: 4.5 TPD
B) Feed : Rice Straw
ISBL
Rice Straw = 373 TPD
Chemical*
Enzyme =1.12 TPD
OSBL
CO2 = 202 TPD
Fuel Grade
Ethanol
Plant
FO$ = 0.3 TPD
Waste = 55 TPD
Dusting = 3 TPD
Bio CNG = 45 TPD
Yeast = NA
EtOH = 80 TPD
* Chemicals:
Nitric Acid (100%)
Others Salts
: 4.3 TPD
: 1.9 TPD
NaOH (100%)
$
FO = Fusel Oil
: 5.2 TPD
Fig. 1.3: Over all material balance for Technology-D
Features:

Bio-ethanol % conversion for one ton of dry biomass is of rice straw and bagasse is
21.3 % and 24.5 % respectively.

Process can be operated with multiple feedstocks (such as rice straw, bagasse, cotton
straw, wheat straw etc.) but not with mixed feed.

Feed size for the process is 200-1000 microns.

Major byproducts are Liquefied CO2 and lignin (17 %).
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
Enzyme consumption for one ton of dry biomass conversion is 3 kg.

Total conversion time from biomass to bio ethanol is 24 hour.

Turndown capacity for the proposed plant of capacity 100 KLPD is about 25% of
maximum capacity.

Pretreatment is based in both acidic & basic media.

Having a demo plant of 10 TPD.

Total conversion time from biomass to bio ethanol is 24 hours.

Enzyme consumption is one third of against the other available technology.

Enzymatic hydrolysis time for is less than 2 hr.

Fermentation time is 3-9 hrs.

Using Composite Biomass Technologies for the pretreatment of biomass.

Employs continuous fermentation along with enzyme recovery and recycling.
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Feasibility Report on
Ligno-Cellulosic Biomass to
2G Ethanol, MRPL
Table 1.5: Technology comparison
Basis – 100KLPD
Ethanol
Tech A
Tech B
Pretreatment /
Fractionation
Pretreatment, enzymatic hydrolysis,
co-fermentation, distillation &
dehydration
Steam explosion with mild acid to
break down lignin structure and expose
hemicelluloses and cellulose.
Criticality in Process
Pretreatment section is critical to
design. No PTR is available.
Process
Lignin Separation
Feed Stock
Amount of Feed
required (MT/day),
Dry Feed
Feed Size
During distillation
Conversion Time
96 – 120 hr
Technical Alcohol, Fusel Oil, Lignin
Rich Cake, Bio-CNG, Power,
Liquefied CO2
100 KLPD
Byproducts
EtOH
Surplus
Power
p
Yeild r
o Solid Waste
d
u
Fusel Oil
c
Trash &
t
Dust
Rice straw
Baggasse
Rice straw
416 - 426
370 - 385
430
5.44 MT/hr 5.74 MT/hr
8.33 MT/hr
6.46 MT/hr
(dry basis)
~ 6 MWh
Lignin
Bio CNG
Steam explosion to break down lignin
structure and expose hemicelluloses and
cellulose.
Steam explosion system is critical to design.
It’s a proprietary item and PTR for two
commercial units is available with the
licensor.
During distillation
20- 100 mm
10 - 40 mm
CO2
B
y
Pretreatment, enzymatic hydrolysis, cofermentation, distillation & dehydration
BioCNG
Technic
al
Alcohol
Fusel
Oil
Trash &
Dust
Rejects
Sulfur
Lignin, Concentrated Stillage, Power
100 KLPD
VENT- 21 MT/hr
16.1 MT/hr(with 60 % MC)
~ 0.78 MWh
Concentrated
Stillage(with 50%
MC)
13.8 MT/hr
70 kg/hr
Solid Waste
0.57 MT/hr
11 kg/hr
10 kg/hr
Fusel Oil
0.04 MT/hr
0.35 MT/hr
0.32 MT/hr
Trash & Dust
0.25 MT/hr
0.68 MT/hr
0.74 MT/hr
Effluent :34.2 MT/h
0.16 MT/hr
0.175 MT/hr
NA
1.57 MT/hr
1.67 MT/hr
71 kg/hr
Secondary Fuel for
Boiler
17 MT/ hr, Rice Husk
Total Ash Generation
9.3 MT/ hr
Format No. EIL 1641-1924 Rev. 1
120 hr
No supplementary fuel required for power
import case.
3.28 MT/hr
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Feasibility Report on
Ligno-Cellulosic Biomass to
2G Ethanol, MRPL
Tech A
Basis – 100KLPD Ethanol
Quantity
Enzyme
Demand
Cost
Supplier
Yeast
Demand
Quantity
Quantity
(Acid,
Base and
other )
Hydroxide
Mixed
Acids
Chemicals
Molasses
(for yeast
incubation)
155
kg/hr
USD 200- 220 / ton
EtOH
(Enzyme + yeast)
1.24 kg/hr
1.12
kg/hr
2,232- 2,480
(Rs/hr)
2,016 –
2240
(Rs/hr)
USD 50/ton EtOH
(Chemicals & other
consumables)
400
kg/hr
Sodium
Hydroxide
(100%)
200 kg/hr
800
Kg/hr
800
kg/hr
Antifoam
3.3 kg/hr
710 kg/hr
880
kg/hr
180 kg/hr
210
kg/hr
530 Kg/ Hr
(100%)
6.9 MT/hr
(Propagation media)
Urea
82.1 kg/hr
Process water
71 -87 m3/ hr
24 m3/ hr
Steam
29-31.2 MT/hr
41 MT/ hr (32% HP @ 25 barg,
68% MP @ 10 barg)
Electricity
Utilities
Yeast
Sodium
Other Salts,
Solvent
Nutrients
Quantity
32,340 40,300
(Rs/hr)
Novozymes/ Equivalent
Cost
Nitric Acid
(60%)
Chemicals
154 kg/hr
Tech B
Cooling
Water
5.3-6 MWh (3.5-4 MWh Core + 1.8-2
MWh for add on Bio-CNG & Liq CO2)
2600-2800 m3/hr ISBL, 2500 m3/hr CPP
~3.5 MWh (ISBL)
810 m3/ hr for ISBL
Chilling
647 m3/hr
Water
Process Air
850 – 950 Nm3/hr
15050 Nm3/hr
Plant Air / IA
400 Nm3/hr
1000 Nm3/hr
33- 35 Acres (ISBL+OSBL)
Typical ISBL 7.5 to 10 acre
Land foot print Area
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Tech A
Tech B
Pilot
1 TPD dry biomass pilot plant
which is in operation since 2009
1 TPD
Demo
A demo plant of 12 TPD dry
biomass under operation since
march 2017 in Pune.
Basis – 100KLPD Ethanol
Current status of
technology as on
EOI cut-off date.
DOCUMENT No.
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Commercial
Multiple
Capacity 800 TPD dry bio mass
from arundo donax (energy grass)
(40,000 MT EtOH/year)
Capacity 1400 TPD, started in
Sep2014
feeds
Wheat Straw, Rice straw, Cotton
stalk, Bagasse & Corn Cob.
Wheat Straw, Rice straw, Arendo
donax, Cotton stalk, Bagasse and
crop residue
Mix Feeds
Not allowed
Not allowed
Lignin rich cake is separated
from solid liquid separation &
used as a boiler fuel along with
secondary fuel.
Lignin and concentrated stillage
can be sold for off-site uses in
energy generation or
Cogeneration facility can be set
up on clients requirements.
Water re-cycling/ Treatment
100% using ETP
100% using ETP based on ZLD
Effluent treatment
Yes, 45 m3/hr
Yes, 34.2 MT/hr
License Fee
Rs. 30 Cr.
6.3 MM€
Life of proposed plant
20 Years
20 Years
50-60 %
25- 30 %
Compatibility to
variable resource
feed biomass
By-product utilization in terms
of Power generation
Turn down capacity of proposed
plant
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DOCUMENT No.
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Basis – 100KLPD Ethanol
Tech C
Tech D
Process
Hemi-hydrolysis, Super critical
hydrolysis, fermentation, distillation
& dehydration
Fractionation, enzymatic
hydrolysis, fermentation,
distillation & dehydration
Pretreatment / Fractionation
Treatment with high temperature
water to separate hemicelluloses
from celluloses & lignin.
Acid and alkali treatment to
separate hemicelluloses, cellulose
and lignin.
Criticality in Process
Main concern in this technology is
supercritical reactor. No PTR is
available.
Lignin Separation
During super critical hydrolysis
Feed Stock
Reactors in fractionation sections
are critical to design. PTR for this
type of equipment are not
available.
60 % at alkali treatment and 40%
at distillation unit
Rice Straw/Bagasse
Amount of Feed required
(MT/day), Dry Feed
325
373/324
Feed Size
< 120 μ
0.2 – 1.0 mm
Conversion Time
~ 12 -24 hr
24 hr
Byproducts
CO2, Lignin
Lignin, Bio-CNG, Power & CO2
100 KLPD
100 KLPD
EtOH
CO2
Yeild
B
y
p
r
o
d
u
c
t
8.4 MT/hr
8.13 MT/hr
Lignin
Surplus Power
~ 6 MWh
Bio CNG
1.88 MT/hr
1.71 MT/hr
Solid Waste
2.3 MT/hr
0.69 MT/hr
Fusel Oil
12.5 kg/hr
16.7 kg/hr
Trash & Dust
0.13 MT/hr
0.083 MT/hr
Secondary Fuel for Boiler
Format No. EIL 1641-1924 Rev. 1
17 MT/ hr, Rice Husk
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2G Ethanol, MRPL
Basis – 100KLPD Ethanol
Enzyme
Demand
Tech C
Quantity
Chemicals
Quantity
(Acid, Base
and
other )
Tech D
47
42
41
Kg/hr
Kg/hr
Kg/hr
23,500 / 21,000 / 20,500
Cost
(Rs/hr) {Rs. 500/kg}
Quantity
Yeast
Demand
DOCUMENT No.
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Page 24 of 111
Yeast strains part of the
technology package. No
separate cost. No regular
supply required with
master bank provision in
proposed plant
293 kg 265 kg
255
/hr
/hr
kg/hr
Cost
Nitric Acid
(60%)
Sodium
Hydroxide
(100%)
Other Salts,
Rs. 100/kg
216
kg/hr
195
kg/hr
188
kg/hr
77
kg/hr
70
kg/hr
67
kg/hr
Process water
20 MT/ hr @ 8 barg
Steam
Electricity
Utilities
9.0 MWh
4.7 MWh
1000 m3/hr ISBL, 2500
Cooling Water
m3/hr CPP
Chilling water
Process Air
331 Nm3/hr
Plant Air / IA
Land foot
print Area
Minimum
capacity for
economic viability
Format No. EIL 1641-1924 Rev. 1
25-40 Acres
8 Acre for ISBL
*Area excluded raw material
and ethanol storage
250 TPD of Biomass
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Tech C
Basis – 100KLPD Ethanol
Current status of
technology as on
EOI cut-off date.
Compatibility to
variable resource
feed biomass
Pilot
Demo
DOCUMENT No.
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Page 25 of 111
Tech D
Pilot plant of 1 TPD dry biomass
3 TPD dry biomass
Demo plant of 10TPD dry biomass
Commercial
Multiple
feeds
Feed Agnostic
Mix Feeds
Not allowed
By-product utilization in terms
Yes, steam can be generated from
the lignin
of Power generation
Water re-cycling/ Treatment
Effluent treatment
Wheat Straw, Rice straw,Cotton
stalk, Bagasse and crop residue
98 %
100% using ETP based on ZLD
Yes
License Fee
Life of proposed plant
Turn down capacity of proposed
plant
15 Years
25 %
1.5.4 Technology Analysis
The inputs provided in Table 1.5 have been received from EOI. The analysis covered below is
based on the data received from licensor.
 Feed Stock Dependence: All the technologies are feed agnoistic and are able to handle
multiple feed stocks, like rice straw, wheat straw, bagasse, corn cob, cotton stalk etc.
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 Mixed Feed Stock Dependence: The technology providers participated in EOI do not provide
this option.
 Conversion efficiency: Technology A, C and D process compared to Technology B require
less feed stock. The feed stock for first two licensors is ½ to 2/3 of Technology B. For 100
KLPD ethanol plant, Technology C need 325 TPD dry biomass. Conversion efficiency for
Technology C is 24.5%. Conversion efficiency of Technology D is 21.5 – 24.7 % and for
Technology A it is 19 – 21 %. Technology B has 16.5 % conversion efficiency.
 Biomass Size Reduction: Technology C required fine grinding (< 120 micron) and
Technology A need coarse grinding ( 25 to 40 mm) for feed, whereas Technology D is in
between ( 0.2 – 1.0 mm). Energy consumed in milling for Technology C is more than
Technology A. Moreover grinding machinery for Technology C is complex compared to
Technology A. Licensor of technology B has not mentioned about the milling of feed.
However it has to be confirmed with the licensor during detailed feasibility study.
 Conversion time: Conversion time for Technology C is estimated 12 – 24 hr while that of
Technology D is about 24 hours. Technology A, B take five times, i.e. 120 hr. This indicates
Technology C and D process need less time than other two.
 Bio CNG: Technology A and D produces Bio CNG from biomass extracted after distillation.
Formed Bio CNG is treated to remove CO2 and impurities. Purified Bio CNG can be sold in
the market. Generation of BioCNG for both the technologies is in the same order. (1.5 – 1.9
MT/hr)
 Enzyme requirement: Technology C uses non enzymatic route, hence for process
requirement of enzyme is not envisaged. Technology D process claim enzyme consumption
around 41 – 47 kg/hr for the process. Technology D uses about 1/3 of the Technology A
requirement (154 – 155 kg/hr) and 1/5 of Technology B requirement (249 kg/hr). Although
Technology D uses less amount of enzyme, the total cost of enzymes don’t defer in large
extent.
 Yeast requirement: Technology A and B use co–fermentation method for the production of
ethanol. Technology C and D use separate C5 & C6 fermentation to produce ethanol. Yeast
required for Technology B is four times of Technology A. Technology D does not require
continuous dose of yeast.
 Steam requirement: Requirement of steam for technology B and D are in the same order (~
20 MT/hr). Technology A needs 1.5 times that of B.
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 Electricity requirement: Power requirement for all licensors except C are in the same order
(5 – 6 MWh) whereas only Technology C needs 9.0 MWh power.
 Process Air: Technology B and A have provided process air requirement. Technology B
needs 4480 Nm3/hr, which is 4.7 times of Technology A requirement (850 – 950 Nm3/hr).
 Land Requirement: Technology D and B recommend near about same area for ISBL.
Technology D and B recommend 8 acre and 7.5 – 10 acre respectively for ISBL. Technology
A and C have provided land requirement for total complex (ISBL & OSBL). Technology A
requires 33 - 35 acre considering two days feed storage whereas Technology C recommend
25 – 40 acre depending on different feed storage scenarios.
 Technology Maturity: Technology B has got commercial plant experience. Technology A
has set up a demo unit for 12 TPD. Technology D has commissioned 10 TPD demonstration
unit whereas Technology C has a working demonstration unit of capacity 3 TPD.
 Power Generation: All the technology provides uses lignin in boiler to generate steam and
electricity. Technology D generates steam by burning the lignin produced from their process.
The generated steam is used for power generation and subsequently in the process.
Technology B claims to generate power by burning lignin and concentrated stillage.
Technology A recommends to burn lignin with secondary fuel and generate electricity.
 Effluent Treatment: Technology providers A, B and D participated in EOI, talked about
effluent treatment and recommend using it. Technology A, B and D recommend to use ETP.
However Technology A and B provided ETP load of 45 m3/hr and 136 m3/hr respectively.
 Water Recycle: All technology provider claims about 100% water recycle (ISBL) in their
process. Technology A, B and D claims 100 % water recycle through ETP unit. Technology
C claim 98% water recycles to process.
 Turn down Capacity: Technology B and A allow turn down capacity of 25-30% and 70%
respectively.
 Water Requirement: The water requirement for technology B is 90 m3/hr for a capacity of
60KLPD.71-87 m3/hr and 110-116 m3/hr of process water is required for technology A and B
respectively for 100 KLPD plant capacity.
1.5.5 Areas of technology requiring detailed assessment
The following areas requiring detailed assessment are:
 Commercial scale operation of 2G Ethanol Process:
The commercial scale plant experience is available for one technology licensor.
And others have demo or pilot scale experience.
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 Commercial experience for pretreatment section is not available:
Bio-digesters used in feed pretreatment section on a commercial are limited.
 Commercial availability of lignin boiler:
Use of lignin as fuel in boiler is recommended by all the licensors;
 Disposal of ash generated from boiler:
The quantity of ash generated from boiler is around 5- 10 TPH and the disposal
of ash is to be addressed properly.
 Biomass availability round the year in 50 km radius:
The availability of biomass round the year depends on proper pre planning and
it is essential to build the ecosystem for ensuring biomass supply. Supply of
secondary fuel for use in boiler is also to be addressed
 Higher cost of production compared to first generation ethanol:
The cost of ethanol production from lignocellulosic biomass is higher than first
generation ethanol and there may be requirement of subsidy for economic
viability and competitive ethanol pricing.
1.6 Capital Cost Estimation
Project Cost Estimate for setting up a Lignocellulosic biomass to 2G Ethanol Complex has been
presented. CAPEX of technology B is presented here for 60 KLPD capacity.
The operating cost is calculated based on the cost information provided by the client
Table 1.6: Cost of feed, product and utilities
Value
Unit
Biomass (Corn Cob)
3500
(Rs/MT)
Secondary Fuel (Cotton Stalk)
2111
(Rs/MT)
39
(Rs/litre)
6.85
(Rs/KWH)
20
(Rs/MT)
Feed
Product
2G Ethanol
Utility
Power(import)
Raw Water
Land cost of 1crore/acre is considered for the costing as provided by the client. Licence fee of
6.3 MM€ and BDEP Fee of 2-3 MM€ taken for costing as provided by the licensor.
It is assumed that Corn cobs of required size is available. No milling equipment cost is
considered in the estimation.
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Key Assumptions
The basic assumptions made for working out the capital cost estimate are as under:

Cost estimate is valid as of 2nd Quarter 2017 price basis

No provision has been made for any future escalation

No provision has been made for any exchange rate variation.

It has been assumed that the project would be implemented on EPCM mode of
execution.

All costs are reflected in INR and all foreign costs have been converted into
equivalent INR using exchange rate of 1USD=Rs. 64.12, 1EURO=Rs.72.18
Exclusions
Following costs have been excluded from the Project cost estimate:

Scope changes

Any survey

Piling

Site development works except roads, drains and boundary wall

Any cost towards dismantling of existing facilities, hot work in existing facilities
if any, removal of unforeseen underground obstructions , any hook up with
existing facilities

Facilities outside the battery limit of the plant

Cost towards statuary clearances.

Any Dispatch facilities for products.

Railway Siding , Township , Rehabilitation cost if any

Any cost (for Feed, Fuel, Utilities, Catalyst & Chemicals, etc.) towards
commissioning / stabilization of the plant or off spec production.

Cost provision for fire-proofing
Capital cost estimate for the identified scope, works out for two case i.e

Power cost as import case
: Power import cost is taken as Rs. 6.85/KWH
as provided by the client

Power cost as generation case
: Power is generated with 5 MWH STG and
secondary fuel is provided in boiler for
additional steam generation.
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The calculated values for the two cases are tabulated below:
Table 1.7: Cost estimate for biomass to Ethanol Complex (Power Import case)
Foreign
Description
Component
Indigenous Component
Total Cost
Ic
Rs. In Lakhs
758 99
859 75
Fc
Technology B
100 77
Table 1.8: Cost estimate for biomass to Ethanol Complex (Power Generation case)
Foreign
Description
Component
Indigenous Component
Total Cost
Ic
Rs. In Lakhs
865 95
966 74
Fc
Technology B
100 78
Validity of cost estimate is as of 2nd Quarter 2017 price basis. The accuracy level of the cost
estimates is ±30%. This accuracy level has been arrived at based on the technical information
received from licensor, detailing done with the in- house data available in EIL.
Based on capital cost, operating cost and sales revenue, IRR has been worked out.
IRR of 12% pretax on total capital works out for ethanol price of around Rs 122.5/Litre, Rs
120.5/Litre for the power import and generation cases respectively.
However the judicious call may be taken by the project proponent at the time of investment
decision with regard to desirable return from the project considering suitable financial
instruments.
This can be verified by the financial consultant based on the exact provision as applicable for
such projects.
Refer Annexure I for detailed cost estimation.
1.7 Environment Impact
The effluents generated in 2G ethanol plant is Solid liquid and gaseous effluents.
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Ash is the solid effluent generated from boiler. Around 3.28 MT/hr of ash is generated in the
boiler.The liquid effluents generated is 34.2 MT/hr and can be treated in ETP.21 MT/hr of
gaseous effluents is generated and is vented to the atmosphere.
1.8 Project Schedule
A project mechanical completion schedule of 24 months has been considered on conventional
mode of execution with zero date as intimation of project clearance date. The total project
execution period has been considered as 27 months including the 3 months period considered
for commissioning. The other activities such as environmental clearance, land acquisition,
availability of feed etc. are to be completed before the zero date. The project schedule is
provided in annexure II.
1.9 Preliminary Plot Plan
The facilities for the Ethanol production plant including ISBL and OSBL are shown in the
preliminary plot plan. The raw material and supplementary fuel storage is considered for two
days. The total plant area is estimated around 50 acres. The preliminary plot Plan is provided in
the annexure III. Although the land considered is in excess of required, this can be utilized for
future expansion and additional facilities like CO2 recovery.
1.10 Social Benefit
Increase in Biofuel production reduces the dependence of oil, thereby reduces greenhouse gas
emission which gives environmental benefits. Less valued feed stock helps for the production
of value added products and increase income for farmer and generates employment in rural
areas.
1.11Way Forward
Preliminary analysis and CAPEX estimation done as per the data available/provided by
technology provider. Detailed feasibility study needs to be carried out to establish viability.
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SECTION - 2
INTRODUCTION
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2.0 Introduction
The reduction of carbon dioxide (CO2) emission has become a major target in efforts to suppress
global warming. Bio-ethanol is considered as an important renewable fuel to partly replace
fossil-derived fuels. Governments around the world have recognized the role that biofuels will
play in a renewable fuels portfolio and have introduced minimum targets for their
implementation in the future. Ligno-cellulosic biomass is seen as an attractive feedstock for
renewable fuels, particularly ethanol.
The Indian economy is growing at a rate of approximately 7 -7.5 percent results the demand for
energy growing at rapid rates to drive this high economic growth. The World Energy Outlook
(WEO) report of the International Energy Agency (IEA) projects that India’s primary energy
demand will increase from 750 Mtoe to 1258-1647 Mtoe between 2011 and 2035 i.e., it will
most likely more than double over these 25 years. The oil demand in India will reach more than
8 million barrels per day in 2035, whereas the current domestic production of crude oil has been
more or less stagnant over the years. The balance is met through imports of crude petroleum
products that cost the country with valuable foreign exchange. Volatile oil prices and the
uncertainty about sustained oil supplies have lead India to search for alternatives, particularly
for substituting petroleum products, to promote energy security. Biofuels are considered among
the most promising alternative options, as they can be produced locally and can be substituted
for diesel and petrol to meet the transportation sector’s requirements. India, like many other
countries, is setting targets for the substitution of petroleum products by biofuels.
Globally, countries have been setting varying targets, ranging from 5 percent to 20 percent for
the transport of fuel products to be provided from renewable sources, to be met at various times
within the period 2010–2030. Developing countries such as India have multiple constraints
benefits in promoting biofuels, such as promoting energy security, rural development and the
reclamation of degraded lands as well as coping with the challenges of land and water scarcity
and improving food security.
In developing economies, food-related feedstock (first generation feedstock) like corn, sugar
etc. is preferably replaced by non food raw materials (second and third generation feedstock),
such as wheat straw, rice straw, bagasse, cotton stalk bamboo etc. Ethanol for use as bio-fuel is
produced by fermentation where certain species of yeast or bacteria metabolize sugars in
oxygen-lean conditions to produce ethanol and carbon dioxide. The main reasons for the
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enhanced development of bio-ethanol are its use as a favorable and near carbon neutral
renewable fuel, thus reducing CO2 emissions and associated climate change.
Whether first, second, or third generation feedstock is used, fermentation produces an alcohollean broth only, as such unusable in industrial and fuel applications. The ethanol must hence be
purified. Fractional distillation can concentrate ethanol to 95.6 vol% (89.5mol %),
corresponding to the azeotropic composition with a boiling point of 78.2 ∘C. Remaining moister
is capture in dehydration column to produce anhydrous fuel grade ethanol.
MRPL is examining the feasibility of setting up Ligno-cellulosic Ethanol production plant in
Karnataka state, India. MRPL has published EOI to identify Technology Providers/ Licensors
which have commercially utilized or prototype technology which is already producing ethanol
from Ligno-Cellulosic Biomass and are interested in setting up and/ or operating Integrated
Ligno-Cellulosic Ethanol Production Plant in India by using domestic agri-based LignoCellulosic feedstock. MRPL is looking for a Plant with capacity to produce ethanol in the range
of 50 KL to 150 KL per day however exact capacity will depend upon the optimum plant sizing,
biomass availability, economic movement of Ethanol for blending, taxes and other factors. EIL
has been selected to prepare a feasibility report on Ligno-cellulosic biomass to 2G-ethanol.
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SECTION - 3
SCOPE OF WORK
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3.0 Scope of Work
The feasibility report shall reflect upon the following broad aspects:
 Project cost, with an accuracy of ± 30%, will be provided based on the inputs
received by MRPL against the published EOI. The project cost estimation was
limited to 2 cases (additional cases shall be done if required by MRPL). The case
shall be finalized in consultation with MRPL. The technical assessment was carried
out for all the cases.
 Comparative analysis and assessment of various 2G-ethanol conversion
technologies: The technologies available will be enlisted based on responses
received against MRPL’s EOI. The assessment will consider factors such as
operability round the year, potential to utilize multiple feedstock and preferably
technology should be feedstock agnostic.
 Comparative
analysis
of
technology
will
include
Alternatives
like
Process/Operation/Maintenance parameters, Compatibility to variable resource
feed biomass. Viability of technology on Commercial scale, Proto type availability,
Land requirement, Multi feed bio mass availability. Analysis will also include
Scalability, Identification of requirement of Chemicals/Enzymes/Guarantees/
Long-term contracts, By-product identification/utilization in terms of Power
generation, water re-cycling etc., effluent treatment, and Green compliance. These
points are covered to the extent of data availability from responses of EOI.
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SECTION - 4
DESIGN BASIS OF STUDY
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4.0 Design Basis
4.1
Ethanol Plant Capacity
Technology comparison study is carried out for 100 KLPD 2G ethanol plant from lignocellulosic biomass and cost estimation is carried out for 60 KLPD plant capacity. Stream hours
considered: 7200 hr/yr.
4.2 Product Specification
The ethanol product quality for ethanol plant from ligno-cellulosic biomass shall meet the
following specifications:
Table 4.1: Product specification for fuel grade ethanol
S. No
Parameters
Value
1
Relative density at 15.6/15.6°C, Max
0.7961
2
Flash point
16.6oC
3
Ethanol content percent by volume at 15.6/15.6°C
Min.(excluding denaturant)
99.50
4
Miscibility with water
Miscible
5
Alkalinity
Nil
6
Acidity (as CH3COOH)mg/l, Max
30
7
Residue on evaporation percent by mass, Max
0.005
8
Aldehyde content (CH3CHO) mg/l, Max
60
9
Copper, mg/kg, Max
0.1
10
Conductivity µS/m, Max
300
11
Methyl alcohol, mg/litre, Max
300
12
Appearance
Clear and bright
4.3 Feed Specification
Ethanol plant should be feed agonistic. It should be able to process different biomass like rice
straw, wheat straw, cotton stalk, sugarcane bagasse etc, as feedstock. Typical composition of
some ligno-cellulosic bio-mass residue is given below in Table 4.2.
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Table 4.2: Typical composition of some ligno-cellulosic bio-mass residues
Cellulose
Hemi-
Lignin
Other
(%)
cellulose (%)
(%)
(Moisture, silica, ash etc)
Bagasse
42
25
20
13
Corn stover
38
26
19
17
Corncob
45
35
15
5
Rice Straw
32
24
18
26
Rice Husk
36
20
20
24
Wheat straw
35
32
21
12
Sweet sorghum
45
27
21
7
Nut Shell
30
30
30
10
Maize Straw
36
28
29
7
Cotton Straw
42
12
15
31
Switch grass
40
30
12
18
Hardwood
40
40
18
2
Pine
44
26
29
1
Feedstock
The following feedstock are considered for the proposed unit

Corn Cob

Rice Straw
The composition of the feedstock is provided in the table.
Table 4.3: Composition of feed stock
Feedstock
Cellulose
Hemicellulose
Lignin
Ash
Moisture
Silica
Others
wt%
wt%
wt%
wt%
wt%
wt%
wt%
Corn Cob
33-34
27-28
18-19
2-3
9-10
0.5-1
3-4
Rice Straw
31-32
16-17
16-17
12-16
9-15
6-8
15-17
Refer Annexure IV for detailed analysis of feed.
The cost information for the feed, product and utilities are provided below.
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Table 4.4: Price of Feed, Product and utilities
Item
Unit
Cost
Biomass(Corn Cob)
Ton
3500
Secondary Biomass(Cotton Stalk)
Ton
2111
Ethanol
kL
39000
Power
kWh
6.85
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SECTION - 5
PROJECT DESCRIPTION
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5.0 Project Description
MRPL has asked EOI’s and the following parties had responded for the EOI’s and their details
are listed as follows:
5.1 Technology Licensors
1. M/s Praj Industries Ltd
2. M/s Beta Renewable S.p.A
3. M/s Renmatix, Inc.
4. DBT – ICT
The EOI data was interpreted with respect to the Biomass availability assessment and
technology evaluation of the given ethanol technologies. Cost estimation for technology B with
± 30% accuracy, Plot plan, Project Plan Implementation, Project Schedule and Financial
analysis of the technologies is also done.
Three technologies based on enzymatic hydrolysis for ethanol production are considered in
detail as a part of feasibility study.
The options for recovery of value added products such as CO2 from fermentation section and
bio-CNG from biomethanation section have been assessed.
The stillage that is left during ethanol distillation is used for producing bio-CNG using
biomethanation reactor. The biomethanation reaction generates CO2, CH4 and H2S by the action
of anaerobic bacteria. The bio-CNG produced is sent to purification section for removing CO2
and H2S and a clean bio-CNG at around 95% purity of methane will be produced for end use.
Raw CO2 gas from fermenters is washed through foam trap designed to reduce the potential
hazard of foam carry over contaminating the CO2 recovery equipment. The CO2 gas is passed
through low pressure scrubber for removal of water soluble impurities in a counter current flow
scheme. The clean gas is compressed to approximate 19 bar(g) pressure at the discharge and
passed through high pressure scrubber to remove heavier impurities from the feed gas and
finally passed through deodorizers that removes odor causing impurities using activated
carbon. Dried, clean and purified CO2 gas at pressure of approx. 18 bar(g) is liquefied in a CO2
liquefaction system operating on ammonia refrigerant.
5.2 Material Balance
Summarized material balance for both technologies are as given below:
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Table 5.1: Material balance for Technology A
Unit of Measurement
Bagasse
Rice Straw
Bagasse
TPD
385
421
Chemicals
TPD
55.1
53.25
Enzyme
TPD
3.73
3.7
Yeast
TPD
0.03
0.03
Ethanol
TPD
79.44
79.44
CO2
TPD
137.74
130.5
Fusel oil
TPD
0.25
0.26
Technical
TPD
1.7
1.7
lignin
TPD
155
199.8
Bio- CNG
TPD
40.2
37.7
Rejects
TPD
17.74
16.4
Sulphur
TPD
4.2
3.8
Mill Loss
TPD
7.6
8.4
Feed
Product
alcohol
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Table 5.2: Material balance for Technology B
Unit of Measurement
Quantity
Biomass
TPD
477.6
Chemicals
TPD
6.85
Enzyme
TPD
6
Yeast
TPD
0.0624
Misc.
TPD
2155
FO
TPD
0.96
Ethanol
TPD
78.72
CO2
TPD
504
lignin
TPD
386.4
Conc. Stillage
TPD
331.2
Waste
TPD
13.68
Trash/Dust
TPD
6
MP Condensate
TPD
518
Effluent
TPD
806.5
Feed
Product
Table 5.3: Material balance for Technology D
Unit of Measurement
Quantity
Feed
Rice Straw
Biomass
TPD
373
Chemicals
TPD
11.4
Enzyme
TPD
1.12
Ethanol
TPD
80
CO2
TPD
202
Waste
TPD
55
Dusting
TPD
3
Bio CNG
TPD
45
Fusel Oil
TPD
0.3
Product
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5.3 Utilities & Off-site Facilities
Besides the main process plant the scope of the project also includes, the following utilities &
offsite facilities as required:

Instrument / Plant air

Power and Steam generation system

Cooling water

DM water

Chilled water

Ethanol storage

Raw material storage

Secondary fuel storage

DG Set
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SECTION - 6
TECHNOLOGY ASSESSMENT
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6.1 Understanding of Ligno-cellulosic Biomass
Understanding ligno-cellulosic biomass, particularly its chemical composition, is a prerequisite
for developing effective pretreatment technologies to deconstruct its rigid structure, designing
enzymes to liberate sugars, particularly cellulase to release glucose, from cellulose, as well as
engineering microorganisms to convert sugars into ethanol and other bio-based chemicals.
Ligno-cellulosic biomass is mainly composed of plant cell walls, with the structural
carbohydrates cellulose and hemi-cellulose and heterogeneous phenolic polymer lignin as its
primary components. However, their contents varies substantially, depending on the species,
variety, climate, soil fertility and fertilization practice, but on average, for agricultural residues
such as corn stover, wheat and rice straw, the cell walls contain about 40% cellulose, 30% hemicellulose and 15% ligin on a dry weight basis. The distinctive feature of plant cell walls is their
two-part structure, as illustrated in Fig. 6.1. Primary cell wall is developed with cell division,
and enlarged during cell growth to a fiberglass-like structure, with crystalline cellulose
microfibrils embedded in a
matrix of polysaccharides
such as hemicelluloses.
The
primary
adjacent
cells
wall
is
of
held
together by a sticky layer,
called the middle lamella,
composed of pectin’s, to
form the conducting tissue
system
numerous
arranged
in
vascular
bundles. On the other
Fig.6.1: Schematic diagram of plant cell walls
hand, when cells cease to
grow, a secondary cell
wall is gradually deposited between the plasma membrane and the primary cell wall for better
mechanical strength and structural reinforcement through the incorporation of lignin for the bulk
of ligno-cellulosic biomass that can be converted to fuels and chemicals. The development of
the conducting tissue system with the rigid secondary cell wall is a critical adaptive event in the
evolution of land plants, which not only facilitates the transport of water and nutrients as well
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as extensive upright growth, but also raises its recalcitrance to degradation due to the interaction
and cross-linking of cellulose, hemicelluloses and lignin as shown in Fig. 6.2.
6.1.1 Cellulose
Cellulose is a polysaccharide composed of linear glucan chains that are linked together by β1,4-glycosidic bonds with cellobiose residues as the repeating unit at different degrees of
polymerization depending on resources, and packed into micro-fibrils which are held together
by intra-molecular hydrogen bonds as well as intermolecular van-der Waals forces. Hydrogen
bonds hold the long cellulose chains tightly together in a crystalline structure rendering the
cellulose insoluble to hydrolysis. The crystalline cellulose must be subjected to some
preliminary chemical or mechanical degradation before it can be broken down into glucose.
6.1.2 Hemicelluloses
Hemicellulose consists of short, highly branched
chains of sugars. It contains pentoses, five-carbon
sugars such as xylose and arabinose, hexoses, sixcarbon sugars such as glucose, galactose, and
mannose, and small amounts of other chemicals.
Hemicelluloses chains are more easily broken
down to form their simple monomeric sugars than
is cellulose because of their highly amorphous and
branched structure. Since pentose sugars comprise
a high percentage of the available sugars in plants,
the ability to recover and ferment them into
ethanol is important for the efficiency and
economics of the process. The exact sugar
composition of hemicelluloses can vary depending
Fig 6.2: Schematic diagram of
Plant Component
on the type of plant.
6.1.3 Lignin
Although lignin is a non-sugar-based polymer and cannot be used as feedstock for ethanol
production via microbial fermentation, it exerts a significant impact on the economic
performance of the corresponding bioconversion processes, since most inhibitors of microbial
growth and fermentation come from this compound during the pretreatment that is needed to
render cellulose amenable to enzymatic attack. Meanwhile, as the most abundant component in
biomass after cellulose, lignin yields more energy when burned and can be used for power
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production in an eco- and environment-friendly mode of the bio-refinery. Moreover, lignin is
an excellent starting material for various products including transportation fuels and valueadded chemicals, which may add credits bioconversion processes and make bio-ethanol more
economically competitive.
In addition to the three major components, cellulose and hemicelluloses that can be hydrolyzed to sugars
for ethanol fermentation, and lignin left after fermentation, other components like proteins and ashes
also affect the process economics. For example, fermentation nutrients are usually needed to
nourish ethanologenic microorganisms, either S. ceresive or Zymomonas mobilis that can be
engineered for ethanol production from lignocellulosic biomass, due to insufficient nutrition in
the feedstock, which raises a concern about the supplementation of nutritional components to
satisfy the basic requirements for cell growth and ethanol fermentation.
6.2 Processes for Ethanol Generation from Ligno-cellulosic Biomass
Ligno-cellulosic biomass can be converted into bio-ethanol using biochemical conversion
technology.
In biochemical conversion the plant fibre
is separated into its components cellulose,
hemicelluloses and lignin. The cellulose
is then further broken down to simple
sugars that are fermented to produce
ethanol. Typically the process is carried
out in 4 stages
1. Physical or chemical pretreatment
of the plant fibers to expose the
cellulose
and
reduce
its
crystallinety.
2. Hydrolysis
of
the
cellulose
polymer, with enzymes or acids,
to convert it into simple sugars
(glucose).
Fig.6.3: Technologies for Ethanol Generation
from Lignocellulosic Biomass
3. Microbial fermentation of these
simple sugars to ethanol.
4. Distillation and dehydration to produce 99.5% pure alcohol.
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Lignin is a byproduct of this process, and this can be used as a boiler fuel or processed into
specialty chemicals. Hydrolysis and fermentation can be conducted simultaneously in one stage
but simultaneous saccharification and fermentation (SSF) is yet to be implemented
commercially, significant advances are being made in this area.
Both the biochemical and thermo chemical pathways require sophisticated processing steps that
have higher operating costs and need significant capital investment compared with grain-based
ethanol processes.
Fig.6.4: Technological routes for Ethanol Generation from Lignocellulosic Biomass
6.3 Process Description for Bio-Ethanol Production
The lignin-hemicellulose-cellulose complex forms stringent seals around cellulose. The first
step in the overall process of lignocellulosic fermentation is breaking this barrier. This is the
most important and rate limiting step in the overall process. Further steps involve isolation and
hydrolysis of cellulose and hemicellulose to generate emendable sugars (saccharification)
followed by fermentation and distillation as shown in Fig 6.5. The pretreatment processes
involve the use of acids, alkalis, steam and/or organic solvents. The aim of this process is to
separate lignin, cellulose, hemicellulose from lignocellulosic biomass. Post pretreatment, the
recalcitrant lignocellulosic biomass becomes susceptible to acid and/or enzymatic hydrolysis as
the cellulosic microfibrils are exposed and/or accessible to hydrolyzing agents.
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In the pretreatment process, small amounts of cellulose and most of hemicellulose is hydrolyzed to sugar
monomers. The pretreated biomass is then subjected to filtration to separate liquids
(hemicellulose hydrolysate) and solid (lignin & cellulose). The liquid is sent to a xylose
(pentose) fermentation column for ethanol production. Solids are subjected to hydrolysis (also
called second stage hydrolysis). This process is mainly accomplished by enzymatic methods
using cellulases. Mild acid hydrolysis using sulfuric and hydrochloric acids is an alternative
procedure. The hydrolyzed sugars such as can be readily fermented to ethanol using various
strains of yeast.
Fig.6.5: Schematics of biomass to bio-ethanol technology
6.3.1 Pretreatment
The usefulness of cellulose as a feedstock has been limited by its rigid structure and difficulty
to breakdown into simple sugars. Pretreatment is necessary to accomplish the following:

Break the lignin-hemicellulose-cellulose complex.

Disrupt/loosen-up the crystalline structure of cellulose.

Increase the porosity of the biomass.
These changes in lignocellulosic materials make it easier for enzymatic saccharification
(hydrolysis), results in higher fermentable sugars levels and will have a significant impact on
the overall process. Cost effective pretreatments are needed to liberate the cellulose from the
lignin/hemicellulose matrix and reduce its crystallinity i.e an ideal pretreatment process should
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have yield high levels of pentoses and the hydrolysates will not have any inhibitory substances.
Pretreatment, involves delignification of the feedstock in order to make cellulose more
accessible in the hydrolysis step, using physical, physicochemical, chemical and biological
treatment. For this step there are several types of processes, with different yields and distinct
effects on the biomass, which in turn have implications on the subsequent steps. Most used
methods for pretreatment is listed in Table 6.1. Pretreatment is a costly separation, accounting
for upto 33% of the total cost the economy needs to be improved, and the release of microbial
and chemical contamination that possibly reduces the overall yield needs further attention.
Table 6.1: Comparison of the different pretreatment processes
Process
Description
Physical
Reaction
time
Xylose
yield
Vapour explosion
Crushed biomass is treated with vapour (saturated, 160°260°C) followed by a rapid decompression.
1-10 min
45%-65%
Thermo-hydrolysis
Uses hot water at high pressure (pressure above the
saturation point) to hydrolyze the hemicellulose.
30 min
88%-98%
Acid hydrolysis
Uses concentrated or diluted sulphuric,
hydrochloric or nitric acids,
2-10 min
75%-90%
Alkaline hydrolysis
Uses bases, like sodium or calcium hydroxides.
2 min
60%-75%
40-60 min
70%-80%
1-4 min
88%
Chemical
Organosolv
Biologic
A mixture of an organic solvent (methanol, bio-ethanol
and acetone, for example) and acid catalyst (H2SO4,
HCL) is used to break internal bonds of lignin and
hemicellulose.
Fungi (molds) are used to soluble the lignin. Generally
used in conjunction with other processes.
Combined
Catalyzed Vapour
Explosion
Addition of H2SO4 (or SO4) or CO2 in the vapour
explosion may increase the efficiency of enzymatic
hydrolysis, reduce the production of inhibitor
compounds, and promote a more complete removal of
hemicellulose.
Afex (ammonia
fiber explosion)
Exposure to liquid ammonia at high temperature and
pressure for a period of time, followed by a rapid
decompression.
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6.3.2 Hydrolysis
Hydrolysis process generates fermentable monomeric sugars from hemicellulose and cellulose
content of lignocellulosic biomass. This can be accomplished by two different processes,
namely,
1. Acid hydrolysis
2. Enzymatic hydrolysis.
Acid hydrolysis
Mineral acids such as sulfuric acid, hydrochloric acid, hydrofluoric acid and nitric acid are
widely employed for the hydrolysis of lignocellulosic biomass. The sulfuric acid-based
hydrolysis process is operated under two different conditions
 Process that uses high sulfuric acid concentration that operates at a lower temperature.
 Process that uses low sulfuric acid concentration and operates at a higher temperature.
Enzymatic hydrolysis
These enzymes are commonly referred to as endoglucanase, exoglucanase and cellobiase,
respectively. The exoglucanases attack the non reducing end of cellulose to form the cellobiose
units. Finally, cellobiase converts cellobiose into D-glucose. The factors affecting activity of
cellulases include enzyme source and the concentration of enzyme. The yield of fermentable
sugar levels obtained from pretreated biomass increases as the enzyme load increases and
cellulose load decreases. A comparison of the different hydrolysis processes is presented in
Table 6.2. For higher conversion and lower metallurgy enzymatic hydrolysis is more favorable
over acid hydrolysis.
Table 6.2: Comparison of different options for 2nd stage hydrolysis
Process
Diluted Acid
Input
Temperature
Time
Saccharification
< 1% H2SO4
215° C
3 min
50%-70%
2-6 h
90%
1.5 day
75%-95%
Concentrated Acid
30%-70% H2SO4
Enzymatic
Cellulase
40° C
70° C
6.3.3 Fermentation
Fermentation is the biological process to convert the hexoses and pentoses into ethanol by a
variety of microorganisms, such as bacteria, yeast or fungi.
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Yeast commonly used for first generation ethanol production, cannot metabolize xylose. Other
yeasts ferment xylose and other pentoses into ethanol. Genetically engineered fungi that
produce large volumes of cellulase, xylanase and hemicellulase enzymes are also used. These
could convert agricultural residues (e.g., corn stover, straw, and sugar cane bagasse) and energy
crops (e.g., switch grass) into fermentable sugars.
When using enzymatic hydrolysis, different integration methods of hydrolysis and fermentation
steps are proposed. In the separate hydrolysis and fermentation (SHF), the liberated cellulose is
treated in a different reactor for hydrolysis and subsequent fermentation than the hydrolyzed
hemicellulose and lignin. Separate hydrolysis and co-fermentation (SHCF) and simultaneous
saccharification and co-fermentation (SSCF) are other possible alternatives.
6.3.4 Distillation and Purification
The water-rich feed stream of the distillation & purification unit, contains ethanol in the range
of 3–6 vol %, which is low in comparison with 12 to 15 vol% obtained from 1st generation
feedstock. Due to the higher water content of the broth, additional distillation efforts are
required. Distillation & purification unit consists of 2 process operations:
1. Binary distillation
2. Adsorption via molecular sieve
Desired separation specification of 99.5 vol% ethanol cannot be achieved by distillation alone
because of the non-ideal solution behavior of the water-ethanol mixture. An azeotrope is
observed when the mixture reaches 95.5% mole purity of ethanol. This is a common
phenomenon that occurs when one attempts to separate a polar substance from an alcohol group
utilizing relative volatilities, because in high alcohol concentrations, the attractive forces of the
alcohol group tend to overpower phase change mechanisms of the mixed polar molecule that is
governed by entropy. Equilibrium stage operations are no longer effective after it meets an
azeotrope, and hence sets a limit on the purity achievable using phase change mechanisms.
Hence adsorption via molecular sieve is required for achieving the desired product
specification.
6.4 Technology Assessment
The following technology licensors has shown their interest to putting up 2G bioethanol plant
in Karnataka for MRPL.
1. Praj Industries Limited
2. Beta renewables, S.p.A
3. Renmatix, Inc.
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4. DBT-ICT
This section presents the brief details of all technology licensers along with their USPs (Unique
Selling Point) such as process description, technical features, critical equipments, product yield,
by products etc.
6.4.1 Technology A
Technology A has executed 1 TPD pilot plant to produce bio-ethanol from ligno-cellulosic
biomass is in operation since 2009 to till date consistently. A 12 TPD integrated smart bio
refinery demonstration plant in operation since March 2017 in Pune, Maharashtra .Technology
A has divided their technology in different sections which are listed below and shown in fig.
6.6
1. Biomass Preparation Section
A. Biomass Storage
B. Biomass Handling & Milling
2. Main Process Plant
A. Pretreatment
B. Enzymatic Hydrolysis
C. Co‐Fermentation
D. Distillation
E. Dehydration
3. Utilities & Auxiliaries
A. Boiler
B. Turbine
C. Water Treatment Plant
D. Chemical Storage
E. Cooling Tower
F. Air Compressor
G. Product Storage
H. Enzyme Storage
4. Residue Handling Section
A. Solid Liquid Separation
B. Whole Stillage Storage Section
C. Waste water treatment plant
5. Off‐Site Packages
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A. Fire Fighting System
B. Control System
C. Weigh Bridge
6. Add On Packages
A. Liquefied CO2 Plant
B. Bio-CNG Plant
6.4.1.1 Material Handling & Wet Washing Section
The purpose of this section is to outline the technical specifications for feed stock handling
system for conveying the feed stock, de-stoning and screening, magnetic particle separation,
intermediate storage, necessary safety controls and instrumentation for automatic operation,
weighing system, vibratory screen system with rated capacity as per layout and parameters
mentioned in these specifications.
The feed stock handling system shall be designed for all feed stock materials mentioned in
technical specifications and for the levels of moisture mentioned in the feed stock.
The complete installation will be outdoor type. All components in system, instrumentation,
motors, gearbox, etc shall be suitable for outdoor installation.
From storage, raw material will be fed to the feed conveyor of feed stock handling system with
the help of front end loaders etc for further processing of size reduction, stones separation, and
removal of foreign particles, intermediate storage and further conveying.
A permanent magnet type metal separator shall be installed on feed conveyer to remove
metallic foreign particles from the feed stock. A proper access will be provided to the magnetic
separator for easy removal of separated metallic particles.
The milling unit will be supplied to crush biomass up to 25 – 40 mm particle size and integrated
with upward and downward conveying system including interconnecting chutes bellows, hoods
for dust extraction system etc. are included in the handling system. The controlled flow rate
from the silo shall be fed to the wet washing system for further processing.
Washing is done at ambient conditions with 3-3.5 % w/w solids. The wet biomass is further
squeezed to increase solid up to 15-16% w/w. The wet washed, sized feed stock shall be
conveyed from wet washing system to pretreatment section with belt / chain conveyor and
washed water will be sent to clarification section for recycle. The clarified water will be
recycled back to washing section and clarifier bottom will be sent for further treatment in biomethanation section.
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Fig. 6.6: Process diagram of Technology A
6.4.1.2 Main Process Plant
Pretreatment Process:
In this section, C5 hydrolysis is done (i.e. conversion of Xylan to Xylose) in a reactor, where
a slurry concentration of 15%‐20% is maintained. The mixed acid solution is continuously fed
as per the requirement. The slurry is treated at about 150 – 170 oC and 5 - 8 bar pressure. The
slurry from reactor is flashed in a flash vessel and then pumped to enzymatic hydrolysis
section. Water from the steam flashing shall be recycled back to process.
The pretreated slurry is fed to the pre-hydrolysis reactor. Reaction conditions maintained are
pH in the range of 5.0 to 5.5, temperature of about 48 to 55 oC at atmospheric pressure before
enzyme addition. Enzyme shall be added to the reactor as per required dose. The reaction will
continue in the pre-hydrolysis reactor for few hrs and then the contents are transferred to main
hydrolysis reactor for further processing.
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Fermentation Section:
The sugar rich slurry from hydrolysis reactor is then cooled to 32 – 34 oC and fed to the
fermenter. Pre-fermenters are provided for yeast propagation and different nutrients are added
as per the required dosages. The pre-fermentor volume is transferred to main fermentor for
fermentation process.
Distillation Section:
Once the desired alcohol is achieved, fermented wash is transferred from fermentor to beer
well and from beer well to distillation section. CO2 evolved during fermentation can be sent
to liquefied CO2 plant. The fermented mash from the co-fermentation section is distilled and
dehydrated to get Fuel grade ethanol.
Split distillation consists of stripping section with following distillation columns.
 Degasifying Column: The primary function of degasifying column is to remove non
condensable gases and low boiling impurities from the fermented mash. Preheated
fermented mash is fed to degassifying column.
 Split Mash Column: The primary function of mash column is to strip off ethanol from
fermented mash. Split mash column helps in reduction of overall steam consumption
in distillation section.
Rectification section consist rectifier cum exhaust column. The primary function of this
column is to concentrate the ethanol. Ethanol is enriched at the top and is drawn out as hydrous
ethanol and is fed to dehydration plant for further concentration.
Dehydration Section:
The process drives the rectified feed through a system of molsieve beds. To allow for
molsieve bed regeneration in continuous operation, twin beds are provided of which one is in
dehydration mode while the other is in regenerating mode. Depending on feed and product
specifications, the dehydration regeneration exchange takes place based on set time cycle. As
the regeneration process releases the adsorbed water together with ethanol content, it is
recycled back to system for reprocessing.
The feed is pumped to evaporator column after preheating in feed pre-heater. The overhead
vapor of evaporator column is superheated to the required operating temperature and circulated
to sieve bed one. After passing through the molsieve, the vapor is condensed, cooled and sent
to storage.
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The regeneration operation forces the release of the moisture from the molsieve, making the
sieve bed 2 ready for the next cycle. The whole stillage generated in distillation shall be
pumped to bio-methanation.
6.4.1.3 Utilities & Auxiliaries
Boiler and Turbine Section:
The solid fuel fired boiler package is envisaged for steam requirements of plant. The high
pressure steam generated in the boiler will be expanded in extraction ‐condensing turbine to
generate electric power. The steam from turbine extraction will be supplied to the process
plant through steam distribution network. The condensate recovered from process plant will
be returned back to the boiler package.
The boiler package comprises the complete boiler system (combustion system, water tube
boiler, super‐heaters, evaporators, economizers, air pre‐heaters), the boiler feed water system
(pressurized de‐aerator tank, boiler feed water pump, chemical dosing systems), fuel and
ash handling system, pollution control system, chimney and balanced draft system,
electrical and instrumentation system for fully automatic operation of the boiler package.
There are following two options for the primary fuel and supplementary fuel of the boiler:
(i) Using wet biomass cake discharged from the process.
(ii) Using dried biomass cake and recovery of moisture as condensate
In first option, the wet biomass cake is blended with supplementary fuel such as rice husk
in appropriate percentage. This well blended mixture will be supplied to boiler as fuel.
In second option, the wet biomass cake will be dried in suitable type of biomass dryer.
The dried biomass will be supplied to boiler as fuel and supplementary fuel rice husk will be
supplied. The moisture evaporated from biomass cake in the dryer can be condensed back
and water from wet biomass cake can be recovered.
The proposed boiler package will have following features:
 Highest possible thermal efficiency
 Fully automatic operation of the boiler
 Online‐real time efficiency monitoring system
 Fully mechanized fuel and ash handling system
 Lowest downtime for cleaning and maintenance
 High circulation ratio
Steam Turbine Package:
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The high pressure steam generated in the boiler will be expanded in extraction ‐ condensing
turbine to generate electric power. The complete and efficient turbine package will be supplied
for efficient power generation from the system. The steam turbo‐generator will be installed
in a separate powerhouse, along with the entire auxiliary equipment and systems.
The turbine control shall be located in the control room, located adjacent to the turbo‐
generator, whereas important indicating instruments shall be provided near the turbine in the
local gauge board.
Water Treatment Plant:
Basic Filtration:
Raw water is pumped from the raw water tank to the self cleaning filter unit for removal of
suspended solids and turbid matter. Prior to chlorine (sodium hypo‐chlorite shall be added for
dis‐infection purpose) this chlorinated, dis‐infected & filtered water is further passed
through an activated carbon filter (ACF).
ACF unit consists of activated carbon media which ensures removal of organic matter &
excess chlorine, the quality of water at the outlet of ACF unit shall be TSS < 5 ppm &
residual chlorine as nil. This filtered water is directed to the process water storage tank and
further transferred to process use. U.V. sterilizer is also installed post ACF unit to eliminate
organic matter. Part of the filtered water is further passed through an ultra‐filtration system
details of which are explained below
Ultra-filtration System:
Ultra‐filtration (UF) is the physical removal of particles and microbiological contaminants
from an aqueous solution using a membrane filter with pore sizes less than 0.04 micron. It
does not remove dissolved ions and small molecules. Membranes may be made from several
polymers including polyacrylonitrile (PAN), poly ether sulfone (PES) and polyvinylidene
fluoride (PVDF). Membrane has durability, ease of manufacturing, resistance to pH
extremes and tolerance to a wide range of chemical cleaning agents. Membranes typically
have a pore size of 0.03 µ (microns), which is effective barrier for bacteria, viruses and
cysts.
Membranes are supplied as flat sheet, spiral wound or hollow fiber modules. Flat sheet
membrane systems are contained in bulky structures and generally operated at low flux rates.
Spiral wound modules are operated in continuous cross flow mode similar to reverse osmosis
membranes. They do not perform a filtrate backwash cycle to lift foulants from the membrane
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surface. Hollow fibre membranes may be submerged in a membrane tank or encased in
pressurized modules.
The offered pressurized hollow fiber membranes will operate in either continuous cross flow
or semi dead‐end modes. Cross flow mode is advantageous for higher suspended solids but
usually requires more pumping energy.
Reverse Osmosis System and Cartridge Filter:
Purpose of cartridge filter is to basically remove very fine particles. The water from cartridge
filter will then be passed to RO unit by means of high‐pressure pump to get the RO product
water.
The pressurized flow enters the RO system. Due to high pressure, a portion of the feed
water permeates through the semi‐permeable RO membranes as pure water while the balance
of the flow exits the system as reject. A single stream of the RO System is proposed with two
stages RO plant is designed for recovery of 80%.
The conductivity indicating transmitter is provided on the RO permeate line monitors the
product water quality. Permeate from RO system is directed to a Degasser Tower to reduce
the CO2 content before it is stored in the RO permeate tank. A cleaning system is provided
for the RO chemical cleaning. A system cleaning is required when the normalized permeate
flow is reduced by 10‐15%, or the differential pressure (DP) increases by 15 percent from the
reference conditions
DM Water Plant System:
Filtered water post RO unit shall further be passed through a D.M. plant system comprising
of mixed bed unit. Remnant cations & anion present in the RO permeate shall be removed
by ion exchange resin present in the mixed bed unit; the mixed bed unit is designed for 20
hours of operation, once the desired output is achieved from the mixed bed unit the resins in
the unit have to be regenerated .
6.4.1.4 Residue Handling Section
Solid-Liquid Separation:
Bio-methanated spent wash is transferred to solid liquid separation section. The solid stream
is used as a feed to boiler and the liquid stream shall be sent to secondary treatment plant
Secondary Treatment Plant:
The liquid portion from solid liquid separation system will be treated through reverse osmosis
system.
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In reverse osmosis, the flow of solvent (water) is reversed by application of external
pressure to the concentrated solution (brackish or saline water). The water that passes through
the membrane would be substantially free from the chemical impurities present in the brackish
or saline water. The water that does not pass through the membrane and is continuously drained
is called concentrate or reject. Bio-methaned spent wash will be treated through reverse
osmosis membranes. The permeate water from the reverse osmosis system will be recycled
back to main ethanol processing plant. The reject may be sold as organic manure as claimed
by technology provider.
6.4.1.5 Add On Packages:
BioCNG Section:
H2S Scrubbing Section
Advanced liquid redox process is used to remove H2S from biogas. The process utilizes the
oxidation reduction potential of chelated iron in aqueous medium for scrubbing hydrogen
sulfide from the biogas. The sulfur present in the hydrogen sulfide is precipitated as elemental
sulfur.
CO2 Scrubbing Section:
The high pressure hydro scrubbing process is based on the difference in solubility of CH4, H2S
and CO2 in water. The process is intensified by further improving the solubility of CO2 by
pressurizing the absorption system.
The biogas after desulfurization fed in to suction of a bio gas compressor via a gas suction filter
where pressure of gas is raised to around 7 to 10 kg/cm²g. Compressed bio gas is sent to bottom
of a pack tower, where pressurized water will flow from top to bottom of the tower in reverse
direction of bio gas for scrubbing of the bio gas to remove contaminant and suspended particles
and absorption of H2S and CO2. At the top of the pack tower compressed but wet methane
emerges and is taken to methane gas dryer. The methane gas dryer is twin bed desiccant dryer
which operates continuously and dries the wet methane to a dew point of minus 60oC. Pre and
post filters are provided in the methane dryer.
High Pressure Compressor:
The standard high pressure compressors type is air‐cooled, and available in required stages
according to the inlet condition available for compression. The compressor is provided to
compress methane and other gases present in the purified biogas.
CO2 Recovery and Liquefaction Section:
CO2 Recovery Section:
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Raw CO2 gas from fermenters is washed through a high capacity stainless steel foam
trap designed to reduce the potential hazard of fermenters foam carry over contaminating the
CO2 recovery equipment. Water spray nozzles are used for rinse‐ down in the advent that
foam is detected. Water exits the foam trap through a seal drain. The raw CO2 gas is sent
through a CO2 gas booster blower. The booster draws feed CO2 gas from the fermenters and
increases its pressure to overcome recovery piping and equipment pressure losses and
deliver elevated suction pressure to the main CO2 compressor. The booster is equipped
with a variable frequency drive that is automatically modulated to maintain a constant CO2
fermentation pressure even with changing CO2 production rates.
CO2 purification section:
In this section, CO2 gas is passed through low pressure CO2 gas scrubber. It is designed to
perform with a high efficiency removal of water soluble impurities due to use of water
scrubbing through structured packing. The scrubber operates with very high alcohol removal
efficiency.
During operation a continuous feed of water automatically adjusted to be proportional to the
CO2 collection rate is evenly distributed over structured packing. Counter current to the water
flow is the flow of impure CO2. The water is collected in the sump and drained. At the top
of the tower the entrained moisture is removed from the CO2 in the demister pad / mist
eliminator and the CO2 exits the tower.
After low pressure water CO2 scrubber, the clean gas is continuously fed to CO2 gas
compressor at constant pressure and this specially designed non‐lubricated, two stages gas
compressor compress the gas to approximate 19 bar (g) pressure at the discharge. The two
stage compressor is complete with first stage and second stage cooling with cooling tower
water and automatic drains with provision of manual checks for drains.
CO2 gas compressed at approximate 19 bar (g) then passes through high pressure water gas
scrubber again to remove heavier impurities from the feed gas, to bring down the impurities
load on the downstream purification system in the plant. After the high pressure water gas
scrubber, the CO2 gas is passed through dual tower deodorizers. The deodorizer removes odor
causing impurities from the high pressure gas. The dual towers are filled with special
activated carbon. CO2 is deodorized in the on‐line tower while the media in the parallel tower
is regenerated with steam at 3.5 bar (g) and followed by natural cooling. After each cycle, this
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regenerated parallel tower is changed to process and the other tower goes for regeneration by
steam.
Clean CO2 gas is passed through high pressure pre-cooler. The cooled CO2 gas from precooler then passes through dual tower dryer filled with molecular sieves. This dryer is
designed for removal of moisture prior to liquefaction of CO2. The dryer has two tower
systems with tower alteration as well as regeneration. It is completely automatic and
regeneration is conducted every cycle. The CO2 feed gas is then passed through a fine filter to
remove any particulate matter.
CO2 Liquefaction Section:
Dried, clean and purified CO2 gas at pressure of 18 bar(g) is liquefied in a CO2 liquefaction
system operating on ammonia refrigerant. CO2 gas is liquefied at - 27 °C in a flooded CO2
condenser. The liquefaction system runs on automatic mode for continuous service. Liquid
CO2 from liquefying system is further purified by removing the non‐condensable gases like
O2, N2, etc., via stripping technology and passed through stripper section based on liquid CO2
being stripped through CO2 reboiler using refrigerant from liquefying system. High purity
liquid CO2 is transferred to NOx removal towers to finally remove the product liquid CO2
from the impurities like NO, NO2 to make the final product liquid CO2 as high purity food
grade quality. Finally this high purity product goes to the liquid CO2 storage tank for
distribution / supplying high purity food grade liquid CO2 consumers through road tankers.
Bio-methanation:
Anaerobic Bio-methanation System:
Anaerobic bio-methanation system uses a bio-digester, to convert organic matter into useful
energy in the form of biogas. The biological process of conversion takes place in controlled
atmosphere ensuring maximum conversion efficiency and production of biogas.
Following are the salient features of the system before entering to the bio-digester, thin stillage
and wet washing purge effluent from is received into a suitably designed equalization tank to
equalize waste water characteristic.
Temperature Control:
Waste water is pumped to bio-digester, via thin stillage cooler which is designed to maintain
the waste water temperature at 38-40oC, with the help of cooling water.
pH Control:
Waste water pH is adjusted to 6.5 ‐ 7.0 by recycling part of the treated effluent.
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Mixing in Bio-digester:
Mixing is done by re‐circulation of biomass using mixing system & further enhanced by gas
propagation. Efficient mixing helps microorganisms to reach fresh food in favorable living
condition & convert organic matter into methane & carbon dioxide. Various sample points are
provided on the shell of bio-digester to measure the concentration of sludge in the bio-digester.
Drain points are provided to drain the excess sludge from bio-digester.
Hydraulic Retention Time (HRT) & Solid Retention Time (SRT):
Bio-digester is designed for adequate hydraulic retention time, which is required for
achieving design parameters while reducing the effects of shock loads & making the process
sturdy. The digested effluent from bio-digester flows to a parallel plate clarifier via degassing
pond. The entrapped gases in the digested effluent are released in degassing pond. The sludge
is settled in the parallel plate clarifier, which is recycled to increase solid retention time in the
bio-digester. The supernatant liquid from clarifier is sent for further treatment. Excess biomass
& sludge is removed from the bottom of bio-digester periodically to avoid excess built up of
solids inside the digester. The biogas produced in bio-digester is collected from top of the biodigester & flows to the gasholder. The gas holder acts as intermediate gas storage & pressure
control device. The biogas is transferred to the boiler house by using biogas blowers. Partly
Biogas is transferred to Bio‐CNG plant. The flare unit is provided for excess gas burning.
6.4.1.6 Overall Material Balance of Plant
Technology A has provided material balance data for the 100KLPD ethanol plant for two
feedstocks.
1. Bagasse
2. Rice straw
Dry feed required for bagasse based plant is 385 TPD while for rice based plant, it is 421 TPD.
Material balance for both feed is shown in fig 6.7.
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A) Feed: Bagasse
ISBL
OSBL
Mill Loss = 7.6 TPD
TPD
CO2 = 137.74 TPD
FO$= 0.25 TPD
Fuel
Grade
Ethanol
Plant
Bagasse = 385 TPD
Chemical*
Enzyme =3.73 TPD
TA# = 1.7 TPD
Lignin = 155 TPD
BioCNG = 40.2 TPD
TPD
Rejects = 17.74 TPD
Yeast = 0.03 TPD
Sulphur = 4.2 TPD
EtOH = 79.44 TPD
* Chemicals:
Mixed Acid
: 9.63 TPD
Molasses
: 21.17 TPD
Nutrients
: 5.05 TPD
Other Chemicals
: 19.25 TPD
B) Feed: Rice Straw
ISBL
OSBL
Mill Loss = 8.4 TPD
TPD
CO2 = 130.5 TPD
FO$ = 0.26 TPD
TA# = 1.7 TPD
Fuel
Grade
Ethanol
Plant
Rice Str = 421 TPD
Chemical*
Enzyme =3.70 TPD
Lignin = 199.8 TPD
BioCNG = 37.7 TPD
TPD
Rejects = 16.4 TPD
Yeast = 0.03 TPD
Sulphur = 3.8 TPD
EtOH = 79.44 TPD
* Chemicals:
Mixed Acid
: 12.78 TPD
Molasses
: 17.04 TPD
Nutrients
: 4.26 TPD
Other Chemicals
: 19.17 TPD
#
TA = Technical Alcohol
$
FO = Fusel Oil
Fig. 6.7: Over all material balance of Technology A
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6.4.1.7 Features

Developed indigenous 2G Ethanol technology in 2009

Bio-ethanol percentage conversion for per ton of dry biomass is of rice straw and
bagasse is 19% and 21% respectively.

Process can be operated with multiple feedstocks (such as rice straw, bagasse, cotton
straw, wheat straw etc.) but not with mixed feed.

Feed size for the process is 25-40 mm.

Major byproducts from technology A are Bio-CNG (9%), liquefied CO2 (10.5%),
Technical Alcohol (4%), Fusel Oil (0.6%), Lignin (47%) and surplus power.

Enzyme and yeast consumption for per ton of dry biomass conversion is 8.7 kg and 0.7
kg respectively.

Total conversion time from biomass to bio ethanol is 100-120 hour.

Approximately 100% water re-cycle via effluent treatment plant in ISBL. However,
some water effluent is there from utilities.

Lignin rich cake is separated from solid liquid separation & used as a boiler fuel along
with secondary fuel.

Turndown capacity for the proposed plant of capacity 100KLPD is about 70 % of
maximum capacity.

Licensor Experience on 1st generation ethanol production technology as a global
equipment supplier.

Licensor Has strength to provide fully integrated end to end scheme for bio-ethanol
plant including OSBL.
 Technology employs Co-fermentation. 
6.4.2 Technology B
Technology B is providing technology for the second generation bio-ethanol production. The
process technology produces fermentable sugars from cellulosic biomasses for the production
of ethanol.
Technology B offers the following benefits:

Proprietary technology without addition of chemicals, that allows high recovery of C5
and C6 sugars (high yield), low sugar degradation and therefore low inhibitor
generation.
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
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Low residence time in the enzymatic hydrolysis step, because of a unique and
proprietary, patent-pending viscosity reduction step.

Highly efficient use of enzyme applied to a high solid content stream.

Simultaneous fermentation of C5 and C6 sugars.
6.4.2.1 Process Description
The main process steps for ethanol production from lignocellulosic feedstocks for technology
B are:
1. Biomass pretreatment to disrupt the lignocellulosic matrix and solubilize C5 and
C6 sugars.
2. Hydrolysis to reduce the cellulose and hemicellulose into fermentable sugars.
3. Fermentation of sugars to ethanol.
4. Solid separation, ethanol recovery and dehydration.
The technology is designed to enable pretreatment process to produce pretreated material that
facilitates enzymatic and microbial activity as shown in fig 6.9. Technology claims to limit
formation of degradation products that could inhibit the performance of hydrolytic enzymes or
fermentative microorganisms. Plant is designed for flexible operation with different feedstocks.
Table 6.3: List of the processes in ISBL
S No.
Area Name
Scope
1
Biomass pretreatment
ISBL
2
Stream cooling
ISBL
3
Viscosity reduction and hydrolysis
ISBL
4
Fermentation
ISBL
5
MO propagation
ISBL
6
Beer column
ISBL
7
Rectifier column
ISBL
8
Ethanol Dehydration
ISBL
9
Daily Ethanol storage
ISBL
10
Lignin separation
ISBL
11
CIP system
ISBL
12
Chemicals storage
ISBL
13
CO2 scrubber
ISBL
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Fig. 6.8: Process schematic for Technology B
Biomass Pretreatment and Stream Cooling:
The biomass will be sent to the pretreatment where the cellulose structure is disrupted, the lignin
seal is broken, and the hemicellulose is partially removed. The objective of this step is to enable
enzymatic access to the cellulose and hemicellulose fractions. Proper pretreatment is critical to
optimize the subsequent hydrolysis. In general, an effective pretreatment is defined by
conditions that maximize recovery of the cellulose and hemicellulose fractions for downstream
processing while, limiting the formation of by-products that inhibits the performance of the
biocatalysts. The combination between auto-hydrolysis and high pressure biomass cooking
processes is used to minimize the formation of inhibitors, eliminating a drawback of the
conventional process. The process uses saturated steam to cleave the chemical bonds between
lignin, cellulose and hemicellulose. The effective outcome in this section has the benefit to
lowering the cost of the process and to reduce the amount of enzyme used in the hydrolysis
step.
Viscosity Reduction and Hydrolysis:
The streams from biomass pretreatment, will be mixed together and fed to the enzymatic
hydrolysis two steps reactors to efficiently liquefy the pretreated material (viscosity reduction
section). This process allows the enzymatic processing of high amount of dry matter providing
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a complete mixing and adequate retention time for the first enzymatic liquefaction of complex
cellulose and hemicellulose, leading to simpler oligomer chains necessary for an efficient
downstream conversion to ethanol. This step will ensure continuous flow of the material into
the fermenters.
Fermentation and CO2 Scrubber:
The mash exiting from the hydrolysis reactors will be cooled and then sent to the simultaneous
saccharification and fermentation (SSF) section. The simultaneous saccharification of both
cellulose to glucose and hemicellulose to pentose and the co-fermentation of both glucose and
pentose will be realized by using special yeast. The SSF offers reduction of the capital costs
due to the combination of hydrolysis and fermentation into a single reactor. In the fermentation,
sugars will be converted to ethanol and carbon dioxide by the action of the yeasts. The
fermentation process employs a system of tanks, all of equal size, to allow the fermentation
process to be operated in a batch mode. The fermentation process generates heat, which is
removed by circulating the fermenting mash through external heat exchangers. From
fermentation, the beer is pumped to the beer well, a holding tank that allows beer to be
continuously fed to the distillation sections.
MO Propagation and Beer Column Section:
Two tanks are used for yeast production where yeasts are grown rapidly with the addition of
process air.
The beer produced during SSF is pumped to a beer stripping column. The bottom stream
(stillage) containing water and solids will be sent to the lignin separation section while overhead
stream is sent to rectification column. The heat is supplied to the beer column by reboiling the
clarified stillage through two indirectly heated reboilers that use exhaust steam coming from
pretreatment. Solid content in clarified stillage could cause fouling issues so that reboilers
capacity is oversized in order to allow the column working at reduced duty with only one
reboiler while cleaning the other.
Rectifier Column Section and Dehydration section:
The ethanol/water stream from the top of the beer column will be condensed and pumped to
rectifier column where it is concentrated to near-azeotropic point. A side draw-off from the
rectifier column will separate the heavy alcohols fraction in order to meet purity requirements
for the ethanol. The heat is supplied to the rectifier column by an indirectly heated reboiler. The
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water stream comes from the bottom of the rectifier column is pumped to the process
condensation tank and then treated to reuse it back in the process.
The rectifier top mixture is in azeotrope condition and cannot be further purified using standard
distillation. The final removal of water/ethanol mixture to produce fuel grade ethanol is
achieved by a molecular sieve dehydration system. The molecular sieves work on the principle
of selective adsorption in the vapor phase. In this case, water is adsorbed on the sieve bed
material while ethanol passes through the bed. The adsorbed water is removed during a
regeneration step and is routed back to the distillation system. Fuel ethanol is pumped to the
daily/off spec tanks opportunely sized for the production at design rate. The production rate of
the ethanol from the distillation/dehydration system will be monitored with in-line instruments,
while moisture content will be monitored with laboratory equipment.
The ethanol from dehydration section is fed into the ethanol daily tank/off spec tank in order
to control the quality of the product before sending it into the product storage section.
Lignin Separation:
The bottom of the beer stripper column containing solids (stillage) is fed to a separation system
in order to separate clarified stillage from high lignin stream. The purpose of the system is to
obtain the high lignin stream with a residual moisture content of about 60%. Technology B has
developed two distinct technical options for this process step, namely filtration and centrifugal
decanters.
The selection is site-specific and can be assessed as part of detailed site-specific feasibility
study. Centrifugal decanters for lignin dewatering are uses centrifugal force to separates solid
particles from water. Through openings situated at the bottom of the equipment it is possible to
separate the clarified stillage stream from the solids (lignin) which, are then transported to the
outlet.
CIP System and Chemical Storage:
In order to keep the process microbiologically clean and to remove residues from heat
exchanger equipment and tanks, a Clean-In-Place (CIP) system will be provided. The cleaning
process will use condensate from the process, thereby minimizing fresh water usage. Caustic
will be used as a cleaning agent for sanitizing and dissolving most of the residues. Chemicals
such as antifoam, caustic soda, urea solution, enzymes are stored in suitable tanks and dosed to
the plant.
6.4.2.2 Byproducts and Effluents
The byproducts of technology B process are:
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1. Lignin-rich solid stream
2. Clarified stillage
3. CO2
The moisture content in the high lignin stream coming out from centrifugal decanters is 60%.
While the expected flow-rate and preliminary characterization of the concentrated stillage after
the evaporation unit BOP section is 0.4 ton for per ton of ethanol production. The moisture
content in this stream is at about 50%.
Fig. 6.9 Simplified scheme of byproduct and effluent streams
1. The lignin-rich stream is the high-solid stream resulting from the lignin separation
section. While lignin has potentially higher value applications that are under
development, it can be also used for energy generation. It can be sold as a fuel or used
in a purposely designed CHP (combined heat and power unit) on-site for generation of
steam and electricity.
2. Clarified stillage is the high-liquid stream resulting from the lignin separation section.
Stillage is a by-product which can be returned to agricultural fields in the proximity of
the plant for nutrient recycling. In other scenarios, this clarified stillage can be sent to
an outside waste water treatment facility for disposal. In most cases however the
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clarified stillage will need to be further processed on-site thus generating streams of
valuable byproducts and effluents. The most appropriate choice is site-specific as it
depends on markets for the co-products and the cost for disposal of any remaining
effluents.
3. The process produces CO2 as a fermentation by-product. The technology includes the
equipment required to collect gaseous streams containing CO2 and process them through
a scrubber unit prior to being vented to the atmosphere. Rather than venting CO2 rich
stream, it is possible to further clean it into commercial-grade CO2 which can be then
liquefied and stored for sale. The viability of this option will depend on the size and
location of the plant as well as the local market for CO2 as an industrial gas.
In addition to the water effluents, the plant will also generate:
 Ashes from the boiler (in case a CHP unit is used on-site to generate energy from
the high lignin stream). In certain instances ashes can be recycled to agricultural
fields for nutrient recovery; in others, however, ashes will need to be disposed
off.
 It is important to emphasize that the nature and specific characteristics of
byproducts and effluents is highly dependent on the design basis and
configuration choices which, in turn, are influenced by a number of
considerations such as location, local value of by-products and cost of disposal
of effluents, etc.
6.4.2.3 Overall Material Balance of Plant
ISBL
Biomass= 477.6 TPD
Chemical*
Enzyme = 6 TPD
Misc. = 2155 TPD TPD
OSBL
Vent = 504 TPD
Fuel
Grade
Ethanol
Plant
Lignin = 386.4 TPD
Conc. Stil = 331.2 TPD
Waste = 13.68 TPD
Trash & Dust = 6 TPD
Yeast = 0.0624 TPD
* Chemicals:
Antifoam
Urea
FO = 0.96 TPD
MP Cond. = 518 TPD
Effluent = 806.5 TPD
EtOH = 78.72 TPD
: 0.0792 TPD
: 1.97 TPD
Sodium Hydroxide (100%)
: 4.8 TPD
Misc.
Propagation Media: 165.6 TPD; Air: 434.4 TPD ; Steam: 969.6 TPD; Process Water : 585.6 TPD
Fig. 6.10: Over all material balance of Technology B
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6.4.2.4 Waste Water Treatment
The clarified stillage stream resulting from the lignin separation step will be further processed
on-site. This and other water effluent streams resulting from the process are collected in an
equalization tank.
The Fig. 6.12 describes a typical stillage/waste water treatments configuration:
Fig. 6.11 Typical stillage / waste water treatments configuration
As outlined in the fig. 6.11, stillage coming from the beer column is processed through a
dewatering section (centrifugal decanter), where a high solid content stream (lignin stream) is
separated. The clarified stillage then goes through a stillage concentration section where a
second high solid stream (concentrated stillage) is recovered.
This stillage concentration section is composed of two separate units:
Evaporation Unit:
The stillage evaporation unit is a multiple effect evaporator designed to produce a concentrated
stillage with a total solid content of about 50% by weight. The subsequent concentrated stillage
stream can be valorized used as a fuel. Most of the condensate from evaporation unit is recycled
to the process, thus lowering the consumption of fresh water.
A Membrane Unit: A portion of the condensate from the evaporation section may be
supplementary treated by membrane unit in order to increase the quality of the water for a
further recycle to the process and/or meet local regulation for water discharge.
The membrane unit will also generate a high COD effluent stream (Membrane Retentate) which
will typically be disposed a wastewater treatment plant based on the local/site regulations.
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6.4.2.5 Features

Commercial scale bio ethanol plant has set up in 2013 bio-ethanol % conversion for per
ton of dry biomass is 16.5%.

Process can be operated with multiple feedstocks (such as rice straw, bagasse, cotton
straw, wheat straw etc.) but not with mixed feed.

Major byproducts are liquefied CO2, concentrated stillage and surplus power.

Claim unique steam explosion process as pretreatment of biomass.

Total conversion time from biomass to bio ethanol is 120 hour.

100% water re-cycle via effluent treatment plant from ISBL.

Lignin and concentrated stillage can be sold for off-site uses in energy generation or
cogeneration facility can be set up on clients’ requirements.

A 2G ethanol technology with experience and learning at commercial scale

1st commercial scale bio ethanol plant started in 2013.

470,000 TPA (dry biomass) started in 2014.

Sustained supply of enzymes with equity partner.

No fine size reduction is required.
6.4.4 Technology C
Technology C also has the process converting ligno-cellulosic biomass to bio-ethanol.
6.4.4.1 Process Description
Technology C is a biomass agnostic process that deconstructs lignocellulosic feed into its key
constituents. Technology C uses a variety of biomass, from woody biomass (hardwood &
softwood) to agricultural residue (bagasse, corn stover, palm residue). Schematic & flow
diagram for Technology C’s process is shown in fig.6.12 & 6.13 respectively.
In the first step biomass undergoes size reduction as necessary, and is then conveyed to a storage
silo. The stored solids are then slurried with water and pumped and heated to reaction
temperature, and then fed to the fractionation reactor. Auto-hydrolysis with hot compressed
water enhances cellulose accessibility by first solubilising hemicelluloses and auto-catalytically
hydrolyzing mainly the xylan content of the hemicelluloses to oligosaccharides and a
monomeric five-carbon (C5) sugar. During this step, biomass particles are slurried with water,
pre-heated to reaction temperature, auto-hydrolyzed in a reactor, and pulverized by steam
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explosion, using equipment adapted from the pulp and paper industry. The residual solids in the
reaction effluent, cellulose and lignin, are recovered from hemicellulose oligomer solution.
The second stage of the process uses super critical water to solubilise the cellulose from the first
step, and then hydrolyze it to glucose and its oligomers. Here the preheated solids from the
hemi-hydrolysis step are slurried with water to achieve desire solids content. The slurry is then
pumped and mixed with super critical water, brought to reaction temperature rapidly, and fed
to the tubular super critical reactor. The cellulose is solubilised to obtain a solution of
oligosaccharides and a monomeric six-carbon (C6) sugars. The reaction mixtures then rapidly
cooled and heat is recovered to provide thermal energy required in the subsequent processes.
Lastly, the solubilised C6 sugar is separated from the remaining solids, primarily lignin.
Fig. 6.12 Schematic diagram for Technology C
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Although having a similar mechanism as the first step hydrolysis of hemicellulose, hydrolyzing
cellulose is significantly more difficult due to two primary factors:
A. The water insoluble crystalline structure formed by abundant intra and inter hydrogen
bonds between each cellulose polymer chain make them very resistant to deconstruction
B. The other components present in biomass, such as hemicelluloses, lignin and cellulose
together and provide rigidity to the structure, protecting cellulose from hydrolysis and
deconstruction.
SOLID/LIQUID
SEPERATION
HEMIHYDROLYSIS
WATER
SUPERCRITICAL
SOLID/LIQUID
HYDROLYSIS
SEPERATION
WATER
HH SLURRY
SH SLURRY
C5 SUGARS
C6 SUGARS
BIOMASS
LIGNIN
Fig. 6.13: Flow diagram for Technology C
Super critical water has the properties significantly different from water at ambient conditions,
and has been successfully used to facilitate various chemical reactions and Technology C super
critical hydrolysis technology draws upon these unique properties.
After the two hydrolysis reactions described above, both C5 and C6 oligosaccharides streams
are optionally refined to produce final monomeric sugars using very small quantities of dilute
acid. Additionally further refining can be done by fermentation where sugar is consumed. In
this step, the sugars are concentrated by evaporation using waste heat from the process.
The co-product lignin is an irregular heterogeneous polymer and is used for its fuel value. The
refined C5 and C6 sugars from refining are mixed and fed to fermentation plant for biological
conversion by yeast into ethanol. The ethanol is distilled to an anhydride form, and after
denaturing, anhydrous ethanol emerges. Two by-products are produces during the sugar
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fermentation to cellulosic ethanol. One is high protein material that is harvested from the spent
yeast organism. A second by-product is composed of carbohydrates that are not converted by
the fermentation organisms. Both by-products can potentially be converted into high-protein
portion could have higher value as feed local livestock operations.
The sugars will be fermented via that consume both the C6 and C5 sugars.
Water is recovered at various locations of the process. This water is collected, treated on site
and returned as process water. Water treatment consists of typical waste water aerobic digestion
coupled with reverse osmosis filtration. Total process water recovery is on the order of 98%.
digestion coupled with reverse osmosis filtration. Total process water recovery is on the order
of 98%.
6.4.4.2 Features

Has novel technology based on supercritical hydrolysis of water.

Super-critical reactor has modular design, i.e. reactor capacity can be increased or
decreased by joining or removing extra reactor tubes.

Bio-ethanol % conversion for per ton of dry biomass is 24.4 %.

Total conversion time from biomass to bio ethanol is 12-24 hours.

The technology produces soluble sugars which can be directly fermented.

No requirment of enzyme in the process.

Time for biomass conversion to sugars: 2-90 minutes.

Low reactor volumes.

Backed by global companies.
6.4.5 Technology D
Cellulosic ethanol technology developed by technology D achieves conversion at high speed
(total process within 24h). The technology is also feedstock agnostic and has been successfully
used with various agricultural feedstock such as rice straw, cotton stalk, corn, bagasse etc.
Technology was implemented as a phase 1 pilot plant of 1 TPD dry biomass. After having run
for six months and the required process optimization, the same plant is being scaled up to 10
TPD in phase 2 and has started operation from April 2016.
Conceptually, the typical process for conversion of lignocellulosic biomass to ethanol route
via enzymatic hydrolysis comprises 5 main steps:
1. Biomass size reduction
2. Pre-treatment
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3. Enzyme Hydrolysis
4. Fermentation
5. Purification & Separation of alcohol
BIOMASS
Size Reduction
Makeup
Makeup
Alkali
Acid
Alkaline
Acid
Reactors
Reactors
Alkali
Acid
Recovery
Recovery
Lignin to
Re - Use
C6 Sugars
Cellulose Enzyme
C5 Sugars
Fermentation
Hydrolysis
Fermentation
Ethanol
Distillation/Drying
Ethanol
Fig. 6.14: The Technology D outline
6.4.5.1 Process Description:
Biomass Size Reduction:
The size reduction system used is a combination of hammer mills system equipped with bucket
elevators to reduce any biomass feedstock.
Pre-Treatment:
Pre-treatment, the first and the most important step in bio-ethanol production is aimed at
loosening the bonds between cellulose, hemicellulose and lignin. Pre-treatment technologies
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such as acid, alkali, hydrothermal, steam explosion of biomass leave the residual solid mass that
is de-lignified for enzymatic hydrolysis to fermentable sugars.
Processing the biomass in a 10-15% flowing slurry form and separation of the biomass
components into substantially homogeneous fractions of cellulose, hemicellulose and lignin has
advantages like:
 It results in proving good mixing conditions and this helps in increasing all the reaction
rates and hence provides lower processing limits.
 The chemicals and enzymes are recycled thereby not only providing considerable
flexibility to the production process with changing feedstocks, the net chemical enzyme
costs are significantly lowered.
 The separated biomass fractions allow for more cost effective treatments to further
products i.e. glucose, xylose and lignin for their next step conversions.
 The overall processing time from size reduction to fermentation & distillation is lowered
to less than a day compared to several days involved in other technologies.
Biomass Fractionation in the Technology D has been designed as a continuous but flexible
operation with the ability to switch between single step and two step sequence adjustable alkali
and acid treatments. The process and system has been designed such that all reaction parameters
can be closely controlled using DCS and SCADA and in a way that no furfural derivatives are
formed and sugar yields are high.
Enzymatic Hydrolysis:
Fractionation of biomass into cellulose and hemicellulose streams by the Technology D process
uses enzymatic hydrolysis that consumes much lower enzymes per kilogram of fermentable
sugars produces. Technology D has three distinct features in this step:
a) Toxics produced: No toxic furfural derivatives produced in the technology on account
of mild and controlled reaction conditions.
b) Inhibitions from substrates and products: Continuous processing overcomes the
inhibitions and makes the reaction rates very rapid.
c) Enzyme deactivation from irreversible adsorption on solid residue: Absence of lignin
or any un-hydrolysable solid matter prevents enzyme deactivation.
Since the system allows for continuous recycle and reuse of the enzyme added, the effective
dosage becomes less than 1 unit/g cellulose residue. Further, the high enzyme dosage, use of
suspension concentration of solids, high quality of separated cellulose, and continuous reaction
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to separate soluble sugars from insoluble cellulose, all factors together reduce the enzyme
reaction time to 2 hours.
Fermentation of Sugars to Ethanol:
The C6 and C5 sugars produced using the fractionation and enzyme technology are converted
to ethanol by yeast strains than give an overall conversion of both sugars at an average of 0.45
lit ethanol/kg sugars. Further, yields are obtained fastest since the fermentation operated as high
cell density fermentation and is completed in 6-9 hours.
The Technology E separates the C5 (from hemicellulose) and the C6 (from cellulose) streams.
Further, it emplys high cell density (HCD) fermentation on account of the consistent quality
sugar streams obtained from the biomass fractionantion process. Continuous high cell density
fermentation is possible due to consistent quality and quantity of sugar streams independent of
the feedstock. Quality in this context implies presence (or absence) of toxic substances and
other substances that may inhibit or affect the fermenting microorganisms. The variation in the
rate of sugar flow into the fermenters arises due to changes in the feedstock composition. These
variations, don’t affect fermentation in terms of ethanol yield and time of fermentation.
The HCD fermentation times are in the range of 3h to 9h at the maximum depending upon
strains used. A comparison on the overall cost of sugar concentration, fermentation, ethanol
distillation and drying easily shows that it is advantageous to distil ethanol after fermentation
than concentrate the sugars before fermentation due to the fact that water evaporation is far
more expensive than evaporating ethanol-water azeotrope.
Ethanol Distillation and Drying:
Ethanol distillation and drying are developed unit operations and technologies and of process
ethanol streams are clear without impurities and suspensions. Typically, the ethanol streams are
concentrated to 95% level which is then dried using the well-known and established molecular
sieve based technology.
These units also do not form part of the Technology D demo-plant wherein the ethanol streams
are simply transferred to the existing main ethanol distillation and drying facility to produce
fuel grade or portable grade ethanol (after sulphur removal).
7.4.5.2 Outflow Streams from the Process Plant
There are three liquid streams that emerge from the process plant. These are as follows:
1. The product ethanol stream.
2. The lignin stream containing some sugars and which is either mildly acidic or basic.
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3. The stream coming as bottom of the alcohol distillation plant.
The lignin stream can be used in two ways.
 The lignin stream is concentrated using the established ‘multiple effect evaporator’
technology to 75% solids and then fired into the boiler to produce stream or power
and steam.
 The stream is taken to biogas digester and converted in to biogas.
Technology D provides following features:
 Lignin produced is soluble, biodegradable and easily converted in to biogas in
compact digester with a biogas output of about 700L/kg dry lignin.
 The silica if present in the biomass (i.e. rice straw) is converted in to soluble salts
and either comes through with clean bio-digester effluent, or forms ash in lignin
boiler. Solid silica can be sold in market while soluble silica is separated and water
recycled.
 All the extractives from the biomass (5-15% on dry basis) emerge with the lignin
stream and get wither burnt to produce steam or converted to biogas depending on
the technology component used.
6.4.5.3 Overall Material Balance of Process Plant
Feed: Bagasse:
ISBL
Fuel
Grade
Ethanol
Plant
Bagasse = 324 TPD
Chemical*
Enzyme =1 TPD
Yeast = NA
OSBL
CO2 = 195 TPD
FO$ = 0.4 TPD
Waste = 16.5 TPD
Dusting = 2 TPD
Bio CNG = 41 TPD
EtOH = 80 TPD
* Chemicals:
Nitric Acid (100%)
NaOH (100%)
Others Salts
: 3.8 TPD
: 4.5 TPD
: 1.7 TPD
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Feed: Rice Straw
ISBL
OSBL
CO2 = 202 TPD
Fuel
Grade
Ethanol
Plant
Rice Straw = 373 TPD
Chemical*
Enzyme =1.12 TPD
FO$ = 0.3 TPD
Waste = 55 TPD
Dusting = 3 TPD
Bio CNG = 45 TPD
Yeast = NA
EtOH = 80 TPD
* Chemicals:
Nitric Acid (100%)
NaOH (100%)
Others Salts
$
: 4.3 TPD
: 5.2 TPD
: 1.9 TPD
FO = Fusel Oil
Fig. 6.15: Over all material balance for Technology D
6.4.5.4 Features:

Bio-ethanol % conversion for one ton of dry biomass is of rice straw and bagasse is 21.3
% and 24.5 % respectively.

Process can be operated with multiple feedstocks (such as rice straw, bagasse, cotton
straw, wheat straw etc.) but not with mixed feed.

Feed size for the process is 200-1000 microns.

Major byproducts are liquefied CO2 and lignin (17 %).

Enzyme consumption for one ton of dry biomass conversion is 3 kg.

Total conversion time from biomass to bio ethanol is 24 hour.

Turndown capacity for the proposed plant of capacity 100KLPD is about 25% of
maximum capacity.

Pretreatment is based in both acidic & basic media.

Having a demo plant of 10TPD.
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
Enzymatic hydrolysis time for is less than 2 hr.

Fermentation time is 3-9 hrs.

Using Composite Biomass Technologies for the pretreatment of biomass.

Employs continuous fermentation along with enzyme recovery and recycling.
A comparison of all the four technology licensors are provided in the table below.
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Feasibility Report on
Ligno-Cellulosic Biomass to
2G Ethanol, MRPL
Basis – 100KLPD Ethanol
Technology A
Technology B
Pretreatment / Fractionation
Criticality in Process
Lignin Separation
Feed Stock
Technology D
Hemi-hydrolysis, Super critical Fractionation, enzymatic hydrolysis,
hydrolysis, fermentation,
fermentation, distillation &
distillation & dehydration
dehydration
Treatment with high
Steam explosion with mild acid to break
Steam explosion to break down lignin structure temperature water to separate Acid and alkali treatment to separate
down lignin structure and expose
and expose hemicelluloses and cellulose.
hemicelluloses from celluloses hemicelluloses, cellulose and lignin.
hemicelluloses and cellulose.
& lignin.
Steam explosion system is critical to design. It’s Main concern in this technology Reactors in fractionation sections are
Pretreatment section is critical to design.
a proprietary item and PTR for two commercial is supercritical reactor. No PTR critical to design. PTR for this type of
No PTR is available.
unit is available with licensor.
is available.
equipment are not available.
60 % at alkali treatment and 40% at
During distillation
During distillation
During super critical hydrolysis
distillation unit
Rice Wheat
Rice Straw
Bagasse
Rice Straw
Bagasse
Straw Straw
Pretreatment, enzymatic hydrolysis, cofermentation, distillation & dehydration
Process
Technology C
Amount of Feed required
(MT/day), Dry Feed
416 - 426
Pretreatment, enzymatic hydrolysis, cofermentation, distillation & dehydration
370 - 385
430
325
373
334
20 – 100 mm
< 120 μ
0.2 – 1.0 mm
324
Feed Size
10 - 40 mm
Conversion Time
96 – 120 hr
120 hr
~ 12 -24 hr
24 hr
Byproducts
Technical Alcohol, Fusel Oil, Lignin
Rich Cake, Bio-CNG, Power, Liquefied
CO2
Lignin, Concentrated Stillage,
Power
CO2, Lignin
Lignin, Bio-CNG, Power & CO2
100 KLPD
100 KLPD
100 LKPD
100 KLPD
EtOH
CO2
5.44 MT/hr
5.74 MT/hr
Lignin
8.33 MT/hr(Dry
basis)
6.46 MT/hr
~ 6 MWh
Byproduct
Surplus Power*
Yield
1.57 MT/hr
Bio CNG**
Technical
Alcohol
71 kg/hr
Fusel Oil
Fusel oil
11 kg/hr
10 kg/hr
0.35 MT/hr
0.32 MT/hr
Trash&
Dust
Rejects
Sulfur
0.68 MT/hr 0.74 MT/hr
0.16 MT/hr 0.175 MT/hr
8.4
MT/ hr
0.78 MWH
Concentrated
1.67 MT/hr Stillage(with
50%MC)
Solid
70 kg/hr
Waste
Solid Waste
Trash & Dust
21 MT/hr
(VENT)
16.1 MT/hr(with 60 % MC)
Fusel oil
Trash &
Dust
Effluent
~ 6 MWh
1.88
MT/hr
1.71
MT/hr
2.3
MT/hr
12.5
Fusel Oil
kg/hr
Trash & 0.13
Dust
MT/hr
0.69
MT/hr
16.7
kg/hr
0.083
MT/hr
13.8 MT/hr
Bio CNG
0.57 MT/hr
Solid
Waste
0.04 MT/hr
0.25 MT/hr
34.2 MT/hr
NA
Secondary Fuel for Boiler
17 MT/ hr, Rice Husk
No secondary fuel for power import case
Total Ash Generation
9.3 MT/ hr
3.28 MT/hr
8.13
MT/hr
17 MT/ hr, Rice Husk
*surplus power depends on the actual boiler 7 power plant configuration
** BioCNG is produced based on specific plant configuration
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Feasibility Report on
Ligno-Cellulosic Biomass to
2G Ethanol, MRPL
Basis – 100KLPD Ethanol
Technology A
154 kg/hr
Quantity
Enzyme
Demand
155 kg/hr
Cost
32,340 - 40,300 (Rs/hr)
Supplier
Novozymes/ Equivalent
Quantity
Yeast
Demand
Technology B
Yeast
1.24 kg/hr
1.12 kg/hr
2,232- 2,480 2,016 – 2240
(Rs/hr)
(Rs/hr)
Cost
Technology C
41
kg/hr
23,500 / 21,000 / 20,500 (Rs/hr) {Rs.
500/kg}
249 kg/hr
47 kg/hr 42 kg/hr
USD 200- 220 / ton EtOH
(Enzyme + yeast)
Novozymes
5.3 kg/hr
USD 50/ton EtOH
(Chemicals & other
consumables)
Yeast strains part of the technology
package. No separate cost. No regular
supply required with master bank
provision in proposed plant
Supplier
Chemicals
Quantity (Acid,
Base and other
)
200 kg/hr
800 kg/hr
Antifoam
3.3 kg/hr
Molasses
(for yeast 710 kg/hr
incubation)
880 kg/hr
Propagation
media
6.9 MT/hr
180 kg/hr
210 kg/hr
Urea (50%
sol in water)
82.1 kg/hr
Mixed
Acids
530 kg/hr
Sodium
Hydroxide
(100%)
Chemicals
800 kg/hr
Other salts
Nutrients
Quantity
Utilities
400 kg/hr
Sodium
Hydroxide
(100%)
Nitric acid
(60%)
Technology D
Process water
71 -87 m3/ hr
24 m3/hr
Steam
29-31.2 MT/hr
~ 41 MT/ hr (32% HP @ 25 barg, 68% MP @ 10
barg)
Electricity
5.3-6 MWh (3.5-4 MWh Core + 1.8-2
MWh for add on Bio-CNG & Liq CO2)
~ 3.5 MWh (ISBL)
Cooling Water
2600-2800 m3/hr ISBL, 2500 m3/hr CPP
810 m3/ hr for ISBL
Nitric
Acid
(60%)
NaOH
(100%)
293
kg /hr
265
kg /hr
255
kg/hr
216
kg/hr
195
kg/hr
188
kg/hr
Other
Salts, Rs. 77 kg/hr 70 kg/hr 67 kg/hr
100/kg
20 MT/ hr @ 8 barg
9.0 MWh
4.7 MWh
1000 m3/hr ISBL, 2500 m3/hr CPP
647 m3/ hr
Chilling Water
Process Air
850 – 950 Nm3/hr
15050 Nm3/hr
Plant Air / IA
400 Nm3/hr
1000 Nm3/hr
331 Nm3/hr
Others
Land foot print Area
33 - 35 Acres (ISBL+OSBL)
Typical ISBL 7.5 to 10 acre
25 – 40 Acres
8 Acre for ISBL
*Area excluded raw material and
ethanol storage
250 TPD of Biomass
Minimum capacity for economic
viability
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Feasibility Report on
Ligno-Cellulosic Biomass to
2G Ethanol, MRPL
d Basis – 100KLPD Ethanol
Current
status of
technology
as on EOI
cut-off
date.
Compatibi
lity to
variable
resource
feed
biomass
Pilot
Demo
Commercial
Multiple feeds
Mix Feeds
Technology A
1 TPD dry biomass pilot plant which is
in operation since 2009
A demo plant of 12 TPD dry biomass
under operation since march 2017 in
Pune.
Technology B
1 TPD Plant
Capacity 800 TPD dry bio mass from arundo
donax (energy grass) (40,000 MT EtOH/year).
Capacity 1400 TPD, started in Sep2014
Wheat Straw, Rice straw, Cotton stalk, Wheat Straw, Rice straw, Arendo donax, Cotton
Bagasse & Corn Cob.
stalk, Bagasse and crop residue
Not allowed
Technology C
Technology D
Pilot plant of 1 TPD dry biomass
3 TPD dry biomass
Demo plant of 10 TPD dry biomass
Feed Agnostic
Wheat Straw, Rice straw, Cotton
stalk, Bagasse and crop residue
Not allowed
Not allowed
Lignin and concentrated stillage can be sold for
off-site uses in energy generation or
Lignin rich cake is separated from solid
By-product utilization in terms
Cogeneration
facility can be set up on clients
liquid separation & used as a boiler fuel
of Power generation
requirements.
along with secondary fuel
Yes, steam can be generated from
the lignin
100% using ETP
100% using ETP for ZLD
Effluent treatment
Yes, 45 m3/hr
Yes, 34.2 MT/hr
License Fee
30 Cr.
6.3 MM€
Plant Life of proposed plant
20 Years
20 Years
15 year
Turn down capacity of proposed
plant
50 - 60 %
25 - 30%
25 %
Format No. EIL 1641-1924 Rev. 1
98 %
100% using ETP
Water re-cycling/ Treatment
Yes
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6.5 Technology Analysis
The inputs provided in Table 6.4 have been received from EOI .The analysis covered below is
based on the data received from licensor.
 Feed Stock Dependence: All the technologies are feed agnostic and are able to handle
multiple feed stocks, like rice straw, wheat straw, bagasse, corn cob, cotton stalk etc.
 Mixed Feed Stock Dependence: The technology providers participated in EOI do not
provide this option.
 Conversion efficiency: Technology A, C and D process compared to Technology B require
less feed stock. The feed stock for first two licensors is ½ to 2/3 of Technology B. For 100
KLPD ethanol plant, Technology C need 325 TPD dry biomass. Conversion efficiency for
Technology C is 24.5%. Conversion efficiency of Technology D is 21.5 – 24.7 % and for
Technology A it is 18.7 – 20.7 %. Technology B has 16.7 – 18.18 % conversion efficiency
respectively.
 Biomass Size Reduction: Technology C required fine grinding (< 120 micron) and
Technology A need coarse grinding ( 25 to 40 mm) for feed, where as Technology D is in
between ( 0.2 – 1.0 mm). Energy consumed in milling for Technology C is more than
Technology A. More over grinding machinery for Technology C is complex compared to
Technology A.
 Conversion time: Conversion time for Technology C is estimated 12 – 24 hr while that of
Technology D is about 24 hours. Technology A and B take five times, i.e. 120 hr. This
indicates Technology C and D need less time than other two.
 Carbon dioxide formation: Technology D process generates maximum CO2 of 202 TPD,
which is 2.6 fold compared to Technology B and 1.5 fold compared to Technology A
processes.
 By product (Acetic acid & Furfural): The technology providers do not produce significant
by product.
 Bio CNG: Technology A and D produces Bio CNG from biomass extracted after distillation.
Formed Bio CNG is treated to remove CO2 and impurities. Purified Bio CNG can be sold in
the market. Generation of BioCNG for both the technologies is in the same order.( 1.5 – 1.9
MT/hr)
 Enzyme requirement: Technology C uses non enzymatic route, hence for process
requirement of enzyme is not envisaged. Technology D process claim enzyme consumption
around 41 – 47 kg/hr for the process. Technology D uses about 1/3 of the Technology A
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requirement (154 – 155 kg/hr) and 1/5 of Technology B requirement (249 kg/hr). Although
Technology D uses less amount of enzyme, the total cost of enzymes don’t defer in large
extent. From the cost point of view, enzyme requirement for all these processes are near about
same. Cost of enzyme for Technology D is 20,500 – 23, 500 INR/hr, which is nearly half –
fold of B ( 45,152 – 49,667 INR/hr). Whereas for Technology A and C this values are 32,340
– 40,000 INR/hr and 27,900 INR/hr.
 Yeast requirement: Technology A and B use co–fermentation method for the production of
ethanol. Technology C and D use separate C5 & C6 fermentation to produce ethanol. Yeast
required for Technology B is four times of Technology A. Technology D does not require
continuous dose of yeast.
 Steam requirement: Requirement of steam for technology B and D are in the same order (~
20 MT/hr). Technology A needs 1.5 times that of B.
 Electricity requirement: Power requirement for all licensers except C are in the same order
(5 – 6 MWh)where as only Technology C needs 9.0 MWh power.
 Process Air: Technology B and A have provided process air requirement. Technology B
needs 4480 Nm3/hr, which is 4.7 times of Technology A requirement (850 – 950 Nm3/hr).
 Land Requirement: Technology D and B recommend near about same area for ISBL.
Technology D and B recommend 8 acre and 7.5 – 10 acre respectively for ISBL. Technology
A and C have provided land requirement for total complex (ISBL & OSBL). Technology A
recommend 33 - 35 acre considering two days feed storage whereas Technology C
recommend 25 – 40 acre depending on different feed storage scenarios.
 Technology Maturity: Technology B Licensor has commercial plant experience.
Technology A has set up a demo unit for 12 TPD and is under operation. Technology D has
commissioned 10 TPD demonstration unit whereas Technology C has a working
demonstration unit of capacity 3 TPD.
 Power Generation: All the technology provides uses lignin in boiler to generate steam and
electricity. Technology D generates steam by burning the lignin produced from their process.
The generated steam is used for power generation and subsequently in the process.
Technology B claims to generate power by burning lignin and concentrated stillage.
Technology A recommends to burn lignin with secondary fuel and generate electricity.
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 Effluent Treatment: Technology providers A, B and D participated in EOI, stated about
effluent treatment and recommend using it. Technology A, B and D recommend using ETP.
However Technology A and B provided ETP load of 45 m3/hr and 136 m3/hr respectively.
 Water Recycle: All technology provider claims about 100% water recycle (ISBL) in their
process. Technology A, B and D claims 100 % water recycle through ETP unit. Technology
C claim 98% water recycles to process.
 Turn down Capacity: Technology D allows 25% turn down whereas B and A allows it to
25-30% and 70% respectively. Although Technology D & B claim 25% turn down, practically
it is infeasible and some equipment may run at 25% turn down.
 Water Requirement: The water requirement for technology B is 90 m3/hr for a capacity of
60KLPD.71-87 m3/hr and 110-116 m3/hr of process water is required for technology A and B
respectively for 100 KLPD plant capacity.
6.5.1 Areas of technology requiring detailed assessment
The following areas requires detailed assessment:
 Commercial scale operation of 2G Ethanol Process:The commercial scale plant
experience is available for one technology licensor. And others have demo or pilot scale
experience.
 Commercial experience for pretreatment section: Bio-digesters used in feed
pretreatment section on a commercial are limited.
 Commercial availability of lignin boiler:Use of lignin as fuel in boiler is recommended
by all the licensors.
 Disposal of ash generated from boiler:The quantity of ash generated from boiler is
around 5- 10 TPH and the disposal of ash is to be addressed properly.
 Biomass availability round the year in 50 km radius:The availability of biomass round
the year depends on proper pre planning and it is essential to build the ecosystem for
ensuring biomass supply. Supply of secondary fuel for use in boiler is also to be
addressed
 Higher cost of production compared to first generation ethanol:The cost of ethanol
production from lignocellulosic biomass is higher than first generation ethanol and there
may be requirement of subsidy for economic viability and competitive ethanol pricing.
The following sections give the details of the proposed 60 KLPD 2G ethanol plant for the
capital cost estimation with Technology B as the licensor.
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SECTION - 7
UTILITIES AND OFFSITES
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Feasibility Report on
Ligno-Cellulosic Biomass to
2G Ethanol, MRPL
7.1 Utilities
The utility consumption and the facilities required have been done based on estimation of
utility consumption of the process units based on the following.

Licensor Data

In-house data as applicable
Table 7.1: Summary of estimated utility requirement
Utility
Raw Water (m3/hr)
Quantity
Technology B
90
810
Cooling water (m3/hr) in Process
Chilling water (m3/hr)
390
Cooling Tower Capacity(m3/hr)
Process
1 X 1000
CPP
1 X 600
DM Water (m3/hr)
Compressed Air (m3/hr)
25
2 X 400
Power (MW)
5
Steam (TPH)
21
The following are the utility systems required for ethanol generation plant.

Raw water system

Cooling water system

DM water and soft water system

Compressed air system

Steam, Power and BFW system
7.1.1 Raw water system
The raw water storage is envisaged for 15 days and the supplies from the water reservoir will
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be pumped to the various consumers in the ethanol plant to meets its process and other
requirements. The requirement of fresh water for plant is around 90 m3/hr.Treated water shall
be used as follows:
 Water for process requirements
 Pump sealing water
 Feed to the DM water system
 Feed to drinking water system
 Service water for operating hose stations for various miscellaneous uses.
7.1.2 Cooling water system
Total requirement of the cooling water for the unit is proposed to be met through two cooling
towers. The cooling water requirement of the unit works out to be approximately 1000 m3/hr
and 600 m3/hr for process and captive power plant respectively. A chiller unit of 830 m3/hr is
additionally envisaged.
7.1.3 DM water and Soft water system
DM water in the ethanol plant is required as boiler feed water make-up
7.1.4 Compressed air system
The compressed air system shall meet the instrument air/ plant air requirements of the unit. A
system has been envisaged to provide a package unit for the above requirements. Within the
package, two centrifugal compressors (one operating and one standby), each of capacity 400
Nm3/hr have been considered. Two instrument air dryer units (both the units will be operating),
each of capacity 400 Nm3/hr have been considered.
7.1.5 Steam, Power and BFW system
The power requirement of the unit is 5 MWH. For the power import case, power will be
imported from grid and the process steam requirement will be met by lignin and concentrated
stillage fired boiler. For the power generation case the power requirement will be met by 5MWH
STG. The boiler is fired with lignin and concentrated stillage along with secondary fuel (cotton
stalk).
The process steam requirement is 21 TPH .The steam will be generated by package steam
boilers. 2 X 15 TPH capacity Steam boiler is considered for power import case. The total steam
requirement for power generation case is ~ 60 TPH. Hence 2 X 41 TPH boilers are considered
for power generation case.
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Feasibility Report on
Ligno-Cellulosic Biomass to
2G Ethanol, MRPL
7.2 Offsite facilities
7.2.1 Storage and Transfer System
The storage facilities are envisaged for biomass feed, supplementary fuel, by product and
product ethanol. The storage for raw material and supplementary fuel are envisaged for two
days where as storage for ethanol is envisaged for 15 days. Storage capacity is based on the
process unit feed / products rates, criticality of operation, turnaround schedules, and emergency
operation. Offsite facilities are divided into following sections:

Raw material storage

Supplementary fuel storage

Finished product storage

By product storage
Table 7.2: Storage details
Days
Units
Technology B
Quantity
Raw material
TPD
271.2
3
TPD
60
15
TPD
47.28
Lignin Storage
15
TPD
Chemicals/Enzyme/Yeast
15
TPD
Intermediate
Storage(Fusel oil)
88.32(dried)
Enzyme: 3.6
Yeast:.0384
Antifoam:0.048
NaOH:2.88
Urea:0.99
Prop. Media:99.36
15
TPD
Supplementary Fuel
Ethanol
Format No. EIL 1641-1924 Rev. 1
4
0.48
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Table 7.3: By product details for 60 KLPD ethanol plant
By product
Units
Quantity
Solid Waste
7.68
Vent
Lignin
Technology B
285.6
TPD
220.8
Concentrated Stillage
187.2
Fusel Oil
0.48
7.3 Flare Systems
Since less gas is generated in the system it can be vented to the atmosphere as per OISD norms.
Hence no flare is envisaged in the ISBL.
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SECTION -8
PROJECT SCHEDULE &
PROJECT EXECUTION
METHODOLOGY
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Enclosed in Annexure II
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SECTION -9
ENVIRONMENT
CONSIDERATIONS
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9.1 ENVIRONMENTAL CONSIDERATIONS
The design of the Project will be on a minimum pollution basis and include all the features
required to ensure that control of all forms of pollution will comply with regulatory &
governmental requirements.
The design approach built into the FEED to avoid/minimise emissions to the air is as follows:

Fugitive emissions from valves will be avoided or minimised by selection of suitable valve
packing, seals etc.

Fugitive emissions from pumps will be minimised by use of dual seals or seal-less pumps
when handling high vapour pressure and hazardous material

Fugitive emissions from flanged connections will be reduced by minimising the number of
flanged connections in high pressure service.

Asbestos will be replaced with safer materials wherever possible, within the scope of this
PROJECT.

Only non-Ozone Depleting Substances will be used within this PROJECT.

Stack emissions from boiler will meet the standards specified in Table 9.1
The HSE Philosophy requires that the level of fugitive emissions emitted during operation of
the plant should be determined by analysis or estimation. The estimated levels will then be
monitored regularly for VOCs and HC. The philosophy requires monitoring of ambient air
quality to ensure that the levels of various pollutants are within the limits. The limits that will
be met is given in Table9. 2
The PROJECT is designed to minimise emissions and the production of waste. The solid waste
that is produced during construction phase will be segregated to allow for safe disposal and
preferably recycle/reuse. Such wastes includes; sieves, activated carbon filters and ion exchange
resins, as well as oily sludge, sanitary sludge, maintenance wastes and spent batteries.
The solid waste that is produced during operation phase will be mostly used for combustion in
boiler and left out portion will be either sold as manure for agricultural fields or to brick and
cement industries.
Any waste that must be disposed of off-site, shall be disposed of by an appropriately authorised
organisation recognised by Central Pollution Control Board/State Pollution Control Board.
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During the operation phase, the treated waste water will be recycled using RO based recycle
plant. Backwash/ regeneration effluent generated from recycle plant shall be stored in the
recycle plant and then pumped for use as horticulture water, fire water make-up and for ash
quenching.
Table 9.1: Standards for Emissions from Boilers Using Agriculture Waste As Fuel
Type of feeding
mechanism
Step Grate
Pollutant
Value
Particulate matter
250 mg / Nm3
Horse Shoe /Pulsating
Particulate matter
Spreader stroker
Particulate matter
500 mg / Nm3
(12% of CO2)
500 mg / Nm3
(12% of CO2)
Table 9. 2: National Ambient Air Quality Standards
Sl.
Pollutant
No.
Time
Concentration in Ambient Air
Weighted
Industrial,
Average
Residential,
Rural & other
areas
1.0
2.0
3.0
4.0
Sulphur
Annual
Dioxide
Average*
(SO2)
Ecologically
Methods of measurement
Sensitive
Area
50 µg/m3
20 µg/m3
-Improved West and Gaeke
24 hours**
80 µg/m3
80 µg/m3
-Ultraviolet Fluorescence
Oxides of
Annual
40 µg/m3
30 µg/m3
-Modified
Nitrogen as
Average*
NO2
24 hours**
80 µg/m3
80 µg/m3
-Chemiluminiscence
Particulate
Annual
60 µg/m3
60 µg/m3
-Gravimetric
Matter ,
Average*
Size<10 µ
24 hours**
100 µg/m3
100 µg/m3
-Beta attenuation
Particulate
Annual
40 µg/m3
40 µg/m3
-Gravimetric
Matter ,
Average*
Size<2.5 µ
24 hours**
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Jacob
&
Hochheiser (Na-Arsenite)
-TOEM
-TOEM
60 µg/m3
60 µg/m3
-Beta attenuation
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Sl.
Pollutant
No.
Time
Concentration in Ambient Air
Weighted
Industrial,
Average
Residential,
Rural & other
areas
8 hours**
5.0
Ozone O3
1 hour
Annual
6.0
Lead(Pb)
Carbon
7.0
Monoxide
(CO)
8.0
9.0
Ammonia
(NH3)
Benzene
100 µg/m3
Ecologically
8 hours**
Methods of measurement
Sensitive
Area
100 µg/m3
-UV Photometric
-Chemilminescence
180 µg/m3
180 µg/m3
Chemical method
0.5 µg/m3
0.5 µg/m3
-AAS/ICP
method after
sampling on EPM 2000 or
Average*
24 hours**
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equivalent filter paper
1.0 µg/m3
1.00 µg/m3
-ED-XRF
using
Teflon
filter
2 mg/m3
2 mg/m3
-Non
Dispersive
Infra
red(NDIR)
1 hour
4 mg/m3
4.0 mg/m3
Spectroscopy
Annual
100 µg/m3
100 µg/m3
-Chemiluminescence
400 µg/m3
400 µg/m3
-Indophenol blue method
05 µg/m3
05 µg/m3
-Gas
Average*
24 hours**
chromotography
Annual
based continues analyser
Average*
-Adsorption
and
Desorption followed by GC
analysis
Annual
10.0
Benzo(a)
Average*
Pyrene (BaP)
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01 ng/m3
01 ng/m3
-Solvent
followed
extraction
by
HPLC/GC
analysis
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Sl.
Pollutant
No.
Time
Concentration in Ambient Air
Weighted
Industrial,
Average
Residential,
Rural & other
areas
Annual
06 ng/m3
Ecologically
Area
06 ng/m3
Nickel (Ni)
- AAS/ICP method after
sampling on EPM 2000 or
Arsenic (As)
equivalent filter paper
Annual
12.0
Methods of measurement
Sensitive
Average*
11.0
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Average*
20 ng/m3
20 ng/m3
AAS/ICP
method
after
sampling on EPM 2000 or
equivalent filter paper
* Annual Arithmetic mean of minimum 104 measurements in a year taken twice a Week 24 hours at uniform interval.
**4 hourly/8 hourly values should be met 98% of the time in a year. However, 2% of the time, it may exceed but not on two consecutive days.
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SECTION 10
PROJECT COST ESTIMATION
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10.0 Cost Estimation
Project Cost Estimate for setting up a Lignocellulosic biomass to 2GEthanol Complex has been
presented. CAPEX of technology B is presented here for 60KLPD capacity.
The operating cost is calculated based on the cost information provided by the client
Table 10.1: Cost of feed, product and utilities
Value
Unit
Biomass (Corn Cob)
3500
(Rs/MT)
Secondary Fuel (Cotton Stalk)
2111
(Rs/MT)
39
(Rs/litre)
6.85
(Rs/KWH)
20
(Rs/MT)
Feed
Product
2G Ethanol
Utility
Power(import)
Raw Water
Land cost of 1crore/acre is considered for the costing as provided by the client. Licence fee of
6.3 MM€ and BDEP Fee of 2-3 MM€ taken for costing as provided by the licensor.
It is assumed that Corn cobs of required size is available. No milling equipment cost is
considered in the estimation.
Gantry system with 300KL day tank with 1 bay and two arms is considered for costing.
Key Assumptions
The basic assumptions made for working out the capital cost estimate are as under:

Cost estimate is valid as of 2nd Quarter 2017 price basis

No provision has been made for any future escalation

No provision has been made for any exchange rate variation.

It has been assumed that the project would be implemented on EPCM mode of
execution.

All costs are reflected in INR and all foreign costs have been converted into
equivalent INR using exchange rate of 1USD=Rs. 64.12, 1EURO=Rs.70.47
Exclusions
Following costs have been excluded from the Project cost estimate:
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
Scope changes

Any survey

Piling

Site development works except roads, drains and boundary wall

Any cost towards dismantling of existing facilities, hot work in existing facilities
if any, removal of unforeseen underground obstructions , any hook up with
existing facilities

Facilities outside the battery limit of the plant

Cost towards statuary clearances.

Any Dispatch facilities for products.

Railway Siding , Township , Rehabilitation cost if any

Any cost (for Feed, Fuel, Utilities, Catalyst & Chemicals, etc.) towards
commissioning / stabilization of the plant or off spec production.

Requirement of any high capacity crane
Capital cost estimate for the identified scope, works out for two case i.e

Power cost as import case
: Power import cost is taken as Rs. 6.85/KWH
as provided by the client

Power cost as generation case
: Power is generated with 5 MWH STG and
secondary fuel is provided in boiler for
additional steam generation.
Note: Total power requirement (ISBL + OSBL) for the proposed plant is 5 MWH, based on the
ISBL requirement provided by the licensor and power calculated for OSBL. It is assumed that
the provided ISBL power quantity is meeting all the ISBL power requirements. Secondary fuel
requirement for the power generation case is based on boiler efficiency assumption.
The calculated values for the two cases are tabulated below:
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Table 10.2: Cost estimate for biomass to Ethanol Complex (Power Import case)
Foreign
Description
Component
Indigenous Component
Total Cost
Ic
Rs. In Lakhs
758 99
859 75
Fc
Technology B
100 77
Table 10.3: Cost estimate for biomass to Ethanol Complex (Power Generation case)
Foreign
Description
Component
Indigenous Component
Total Cost
Ic
Rs. In Lakhs
865 95
966 74
Fc
Technology B
100 78
Validity of cost estimate is as of 2nd Quarter 2017 price basis. The accuracy level of the cost
estimates is ±30%. This accuracy level has been arrived at based on the technical information
received from licensor, detailing done with the in- house data available in EIL.
Based on capital cost, operating cost and sales revenue, IRR has been worked out.
IRR of 12% pretax on total capital works out for ethanol price of around Rs 122.5/Litre, Rs
120.5/Litre for the power import and generation cases respectively.
This can be verified by the financial consultant based on the exact provision as applicable for
such projects. 
Refer Annexure I for detailed cost estimation.
Refer Annexure V for the licensor data on which the capital cost estimation has been worked
out.
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SECTION 11
PRELIMINARY PLOT PLAN
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11.1 Plot Plan
The table top plot plan for the proposed lignocellulosic ethanol plant is provided in AnnexureIII.
The overall plot plan area is 50 acres and is comprised of the following sub sections:
 Process units
 Green area
 Feed storage and manure
 Product storage
 Secondary Treatment
 Utility lock
 DG Set and Diesel Storage Area
 Cooling tower and CWTP
 Feed water storage and power house
 Control room, administrative building and laboratory
Process units: The process facilities are designed adhering to maintenance, safety and quality
standards considering constructability, economics and operations in to account.
Feed storage and manure: Two days of storage is considered biomass and secondary fuel for
use in boiler along with manure storage.
Product Storage: 15 days storage is considered for ethanol product storage.
Secondary process/treatment: It contains effluent water treatment section for treating various
effluents generated in the ethanol production process.
Utility Block: It contains compressor, cooling tower, chiller, DM plant, softening unit, plant
air package etc.
DG Set and Diesel Storage Area: It contains DG set and storage area for power back up.
Cooling tower and CWTP: It contains cooling tower and treatment plant.
Feed water storage and Power House: It contains boiler/ steam turbine system and raw water
storage tanks.
Control room, Administration and Laboratory: The area for laboratory, administrative
building, control room, canteen are included in plot plan.
Flare unit: No Flare unit is envisaged in the process unit.
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Feasibility Report on
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2G Ethanol, MRPL
SECTION 12
WAY FORWARD
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12.1 Way Forward:
Technology Assessment:
Preliminary analysis of technologies has been carried out and it is found that enzymatic route
is a relatively mature and may be considered after detailed study.
The following issues need to be addressed during the detailed feasibility study.

Commercial scale operation of 2G ethanol process

The commercial scale plant experience is available for one technology licensor.
Other licensors have demo or pilot scale experience.

Commercial experience for pretreatment section.


Commercial availability of lignin boiler.


Bio-digesters used in feed pretreatment section on a commercial scale are limited.
Use of lignin as fuel in boiler is recommended by all the licensors.
Disposal of ash generated from boiler.

The quantity of ash generated from boiler is around 5- 10 TPH and the disposal of
ash is to be addressed properly.

By products recovery

Production of CO2 and Bio-CNG can be considered in a phases depending on the
local market demand.
Cost Assessment:
Based on capital cost, operating cost and sales revenue, IRR has been worked out.
IRR of 12% pretax on total capital works out for ethanol price of around Rs 122.5/Litre, Rs
120.5/Litre for the power import and generation cases respectively.
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References:
EOI Data of following four licensor
1. M/s Praj Industries Ltd.
2. M/s Beta Renewables, S.p.A
3. M/s Renmatix
4. DBT – ICT
5. In house Data
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