List of Figures
Figure 1:
Process block diagram of integrated sago-based bioethanol plant
Figure 2:
Sago-based bioethanol plant
Figure 3:
Combined heat and power (CHP) System
Figure 4:
Wastewater treatment plant (WWTP)
Figure 5:
Various scenarios versus payback period
Sago Starch Processing Plant
(SSPP)
Biomasses
Starch
Combined Heat and Power
(CHP) System
Steam and
Electricity
Biogas
Electricity
Starch
Electricity
to Grid
Electricity
Lignin
Wastewater Treatment Plant
(WWTP)
Treated Water
Sago Bioethanol Plant
(SBP)
Wastewater
Nutrient rich stream
Ethanol
Figure 1: Process block diagram of integrated sago-based bioethanol plant
Figure 2: Sago-based bioethanol plant
Figure 3: Combined heat and power (CHP) System
Figure 4: Wastewater treatment plant (WWTP)
Various Scenario vs Payback Period
14.00
13.05
12.17
12.06
12.00
10.00
Payback Period
8.63
8.45
8.00
6.19
6.58
6.44
6.00
4.00
2.00
0.00
Starch, c/w labour
Starch, w/o labour
Fibre, w/o labour
Bark, w/o labour
Scenarios
Produce Enzyme
Purchase Enzyme
Figure 5: Various scenarios versus payback period
Fibre + Bark, c/w labour
Fibre + Bark, w/o labour
Table 1: Sago starch and biomasses composition
1
Starch
Soluble dietary fibres
Insoluble dietary fibers
Cellulose
Hemicellulose
Lignin
Moisture
Acetate
Ash
Protein
Lipids
Starch
73.7
3.3
4.0
16.1
0.2
2.4
0.3
Composition (%, dry basis)
2
Fibre
52
16
9.8
5.2
4
15.6
4
1.4
-
3
Bark
23.1
17.31
18
2.76
38.83
-
Data provided by 1Dwiarti et al., 2007; 2Thangavelu et al., 2014; 3University Putra Malaysia
and estimated based on 4Humbird et al., 2011 (NREL report).
Table 2: Sugars contained in hydrolysed sago starch sample (Dwiarti et al., 2007)
Glucose
Xylose
Cellobiose
Sucrose
Maltose
Unhydrolysed oligasacchaccharides
Composition (%)
42.8
5.4
2.3
1.3
23.5
24.7
Dwiarti, L., Otsuka, M., Miura, S., Yaguchi, M., Okabe, M., 2007. Itaconic acid production
using sago starch hydrolysate by Aspergillus terreus TN484-M1. Bioresource
Technology, 98, 3329–3337.
Thangavelu, S. K., Ahmed, A. S., Ani, F. N., 2014. Bioethanol production from sago pith
waste using microwave hydrothermal hydrolysis accelerated by carbon dioxide. Applied
Energy, 128, 277–283.
Humbird, D., Davis, R., Tao, L., Kinchin, C., Hsu, D., Aden, A., Schoen, P., Lukas, J., Olthof,
B., Worley, M., Sexton, D., Dudgeon, D., 2011. Process design and economics for
biochemical conversion of Lignocellulosic biomass to ethanol: Diluted-acid pretreatment and enzymatic hydrolysis of corn stover. National Renewable Energy
Laboratory, NREL/TP-5100-47764, May 2011.
Table 3: Conversion rate for pre-treatment, enzymatic hydrolysis and fermentation processes (Humbird et al., 2011)
Pre-treatment
Conversion
Cellulose to Glucolig
Cellulose to Cellobiose
Cellulose to Glucose
Cellulose to HMF
Xylan to Oligomer
Xylan to Xylan
Xylan to Furfural
Xylan to Tar
Mannan to Oligomer
Mannan to Mannose
Mannan to HMF
Galactan to Oligomer
Galactan to Galactose
Galactan to HMF
Arabinan to Oligomer
Arabinan to Arabinose
Arabinan to Furfural
Arabinan to Tar
Acetate to Oligomer
Acetate to Acetic Acid
Furfural to Tar
HMF to Tar
Lignin to soluble lignin
Rate (%)
0.3
0.0
9.9
0.3
2.4
90.0
5.0
0.0
2.4
90.0
5.0
2.4
90.0
5.0
2.4
90.0
5.0
0.0
0.0
100.0
100.0
100.0
5.0
Enzymatic Hydrolysis
Conversion
Rate (%)
Cellulose to Glucolig
4.0
Cellulose to Cellobiose
1.2
Cellulose to Glucose
90.0
Cellobiose to Glucose
100.0
Fermentation
Conversion
Glucose to Ethanol
Glucose to Zymo (cell mass)
Glucose to Glycerol
Glucose to Succinic Acid
Glucose to Acetic Acid
Glucose to Lactic Acid
Xylose to Ethanol
Xylose to Zymo
Xylose to Glycerol
Xylose to Xylitol
Xylose to Succinic Acid
Xylose to Acetic Acid
Xylose to Lactic Acid
Arabinose to Ethanol
Arabinose to Zymo
Arabinose to Glycerol
Arabinose to Succinic Acid
Rate (%)
95.0
2.0
0.4
0.6
0.0
0.0
85.0
1.9
0.3
4.6
0.9
0.0
0.0
85.0
1.9
0.3
1.5
Table 4: Utility consumptions of sago-based ethanol production plant (purchase enzyme)
Process unit
Feedstock Handling
Pre-treatment
Hydrolysis & Fermentation
Enzyme production
Recovery
Total
Process unit
Feedstock Handling
Pre-treatment
Hydrolysis & Fermentation
Enzyme production
Recovery
Total
Process Water
(kg/d)
81523
81523
Starch
Electricity
(kW)
4.95
32.72
15.18
12.23
65.08
Steam
(kg/s)
0.05 (LP)
0.19 (HP)
0.24
Process Water
(kg/d)
41514
41514
Fibre
Electricity
(kW)
2.66
17.61
8.17
6.58
35.02
Steam
(kg/s)
0.024 (LP)
0.098 (HP)
0.122
Process Water
(kg/d)
54376
54376
Bark
Electricity
(kW)
4.21
27.81
12.91
10.40
55.33
Steam
(kg/s)
0.0381 (LP)
0.1286 (HP)
0.1667
Process Water
(kg/d)
96553
96553
Fibre + Bark
Electricity
(kW)
6.87
45.42
21.08
16.99
90.36
Steam
(kg/s)
0.0623 (LP)
0.2240 (HP)
0.2863
Table 5: Utility consumptions of sago-based ethanol production plant (produce enzyme on-site)
Process unit
Feedstock Handling
Pre-treatment
Hydrolysis & Fermentation
Enzyme production
Recovery
Total
Process unit
Feedstock Handling
Pre-treatment
Hydrolysis & Fermentation
Enzyme production
Recovery
Total
Process Water
(kg/d)
82685
86
82771
Starch
Electricity
(kW)
4.95
32.72
15.18
30.76
12.23
95.84
Steam
(kg/s)
0.045 (LP)
0.168 (HP)
0.213
Process Water
(kg/d)
40290
378
40668
Fibre
Electricity
(kW)
2.66
17.61
8.17
16.55
6.58
51.57
Steam
(kg/s)
0.024 (LP)
0.095 (HP)
0.119
Process Water
(kg/d)
73475
882
74357
Bark
Electricity
(kW)
4.21
27.81
12.91
26.15
10.40
81.48
Steam
(kg/s)
0.0381 (LP)
0.1186 (HP)
0.1567
Process Water
(kg/d)
96215
1260
97475
Fibre + Bark
Electricity
(kW)
6.87
45.42
21.08
42.70
16.99
133.06
Steam
(kg/s)
0.0623 (LP)
0.2104 (HP)
0.2727
Table 6: Cost prices of products, raw materials and utilities
Cost price (USD/kg)
Products
1
Ethanol
0.9204
Raw materials
2
Sulfuric acid (H2SO4), 93%
2
Ammonia (NH3)
2
Corn steep liquor (CSL)
2
Diammonium phosphate (DAP)
1
Cellulase enzyme
2
Caustic
2
Lime
2
Boiler chemicals
2
Cooling tower chemicals
0.0880
0.4394
0.0556
0.9667
3.1200
0.1495
0.1993
4.9959
2.9939
Utilities
2
Fresh water
3
Electricity
0.0002
0.1375 (USD/kWh)
Data extracted from 1Sadhukhan et al., 2008; 2Humbird et al., 2011; and 3Department of
Energy & Climate Change.
Sadhukhan, J., Mustafa, M. A., Misailidis, N., Mateos-Salvador, F., Du, C., Campbell, G. M.,
2008. Value analysis tool for feasibility studies of biorefineries integrated with value
added production. Chemical Engineering Science, 63, 503–519.
Department of Energy & Climate Change. Quarterly energy prices: March 2014. A National
Statistics Publication 2014, <https://www.gov.uk/government/statistics/quarterlyenergy-prices-march-2014> [cited on October 2014]
Table 7: Technical results (purchase enzyme)
Feed Amount (ton/d , dry basis)
Produced ethanol (ton/d)
Yield
Generated Lignin to CHP system (ton/d)
Generated biogas (ton/d)
Generated energy (kW)
Total generated VHP steam (kg/s)
Required LP steam (kg/s)
Required HP steam (kg/s)
Generated Electricity (kW)
Eff. of electricity generation (%)
Electricity consumption (kW)
- Ethanol Production
- WWTP
- Storage and Utilities
Electricity to grid (kW)
Electricity consumption / ethanol
produced (kW/ton . d)
Total required water (ton/d)
Required make up water (ton/d)
Required make up water / ethanol
produced (ton/ton.d)
Starch
12
4.283
0.36
6.508
3.814
1337
0.4537
0.1857
0.0448
233.21
14
125.68
65.08
42.44
18.16
107.53
Fibre
6.458
2.257
0.35
3.430
1.974
699.64
0.24
0.10
0.02
120.6
14
67.64
35.05
22.84
9.77
52.96
Bark
10.202
2.946
0.29
4.471
2.559
910
0.31
0.13
0.04
148.97
14
106.85
55.33
36.08
15.44
42.12
Fibre + Bark
16.660
5.232
0.31
7.930
4.558
1617
0.55
0.22
0.06
275.6
14
174.49
90.36
58.92
25.21
101.11
15.16
81.523
15.860
15.53
41.514
7.543
18.78
54.376
10.325
17.27
96.553
18.090
3.70
3.34
3.51
3.46
Table 8: Technical results (produce enzyme on-site)
Feed Amount (ton/d , dry basis)
Produced ethanol (ton/d)
Yield
Generated Lignin to CHP system (ton/d)
Generated biogas (ton/d)
Generated energy (kW)
Total generated VHP steam (kg/s)
Required LP steam (kg/s)
Required HP steam (kg/s)
Generated Electricity (kW)
Eff. of electricity generation (%)
Electricity consumption (kW)
- Ethanol Production
- WWTP
- Storage and Utilities
Electricity to grid (kW)
Electricity consumption / ethanol
produced (kW/ton . d)
Total required water (ton/d)
Required make up water (ton/d)
Required make up water / ethanol
produced (ton/ton.d)
Starch
Fibre
Bark
Fibre + Bark
12
4.171
0.35
6.338
3.718
1303
0.41
0.18
0.04
217
14%
156.43
95.84
42.44
18.15
60.56
6.458
2.008
0.31
3.220
1.856
657
0.22
0.09
0.02
116.63
14%
84.18
51.57
22.84
9.77
32.44
10.202
2.745
0.27
4.136
2.444
852
0.29
0.12
0.04
136.4
14%
133.00
81.48
36.08
15.44
3.40
16.660
4.750
0.28
7.647
4.398
1559
0.53
0.22
0.06
252
14%
217.19
133.06
58.92
25.21
35.30
23
82.277
18.750
25.70
40.668
8.715
29.68
74.357
16.389
28.15
97.475
21.754
4.50
4.34
5.97
4.60
Table 9: Mass streams of sago-based ethanol production plant with enzyme production on-site
Streams (kg/d, dry basis)
Pre-treatment
Biomass
Process water
Sulfuric acid
Ammonia
Hydrolysis and Fermentation
Hydrolysate
Cellulase enzyme
Hydrolysate slurry
DAP
CSL
Inoculum
Ethanol Recovery
Beer
Ethanol vapour (beer column)
Beer stillage
Vent
Ethanol vapour (rectification column)
Ethanol / Water
Dehydrated Ethanol
Enzyme Production
Hydrolysate Slurry (To enzyme production)
Lignin Separation
Lignin (To CHP system)
Filtrate (To WWTP)
Starch
With enzyme production on site
Fibre
Bark
Fibre + Bark
12000
18566+34119+30000
228
123
6458
10050+13439+16800
123
67
10202
16981+33495+23000
194
121
16660
26540+50675
317
183
50336
105
49591
16.3
126
4919
28163
458
23621
7.8
59
2343
51347
1068
48315
16
121
4792
79506
1527
75933
25
190
7532
78186
10170
67911
105
5476
1285
4192
39725
5167
34504
55
3218
1200
2018
51018
6636
44313
69
3597
838
2759
94809
12522
81938
350
6461
1711
4750
850
5000
4100
5100
6338
61583
3220
31290
4136
40184
7647
74303
Table 10: Mass streams of sago-based ethanol production plant without enzyme production on-site
Streams (kg/d, dry basis)
Pre-treatment
Biomass
Process water
Sulfuric acid
Ammonia
Hydrolysis and Fermentation
Hydrolysate
Cellulase enzyme
Hydrolysate slurry
DAP
CSL
Inoculum
Ethanol Recovery
Beer
Ethanol vapour (beer column)
Beer stillage
Vent
Ethanol vapour (rectification column)
Ethanol / Water
Dehydrated Ethanol
Lignin Separation
Lignin (To CHP system)
Filtrate (To WWTP)
Starch
Without enzyme production on site
Fibre
Bark
Fibre + Bark
12000
18406+34117+29000
228
123
6458
9965+18439+13110
123
67
10202
16644+33495
194
121
16660
26287+50679
317
183
50333
104.5
50438
16.61
126
4992.5
28181
458
28639
9.31
70.5
2795
51755
1068
52823
17.21
130
5133.5
79498
1527
81025
26.2
199
7885
80278
10442
69728
109
5623
1319
4304
42296
5501.6
36737
57
2963
695
2268
55160
7175
47910
75
3867
906
2960
98109
12774
84967
369
6729
1469
5260
6508
63231
3429
33315
4471
43447
7930
77050
Table 11: Economic performances
Raw material
Scenario
Total capital cost (million $)
Feedstock handling (million $)
Pre-treatment (million $)
Hydrolysis and fermentation (million $)
Cellulase enzyme production (million $)
Ethanol recovery (distillation) (million $)
WWTP (million $)
Storage System (million $)
Utilities system (million $)
CHP system (million $)
Total Operating Cost (million $)
Revenue (million $)
Profit (million $)
Payback Period (year)
Purchase Enzyme
Fibre + Bark
c/w Labour
w/o Labour
7.111
7.110
0.580
0.580
1.310
1.310
0.776
0.776
0.810
0.810
1.471
1.471
0.242
0.242
0.368
0.368
1.561
1.561
2.149
1.671
1.370
1.370
(0.779)
(0.301)
Not Feasible
Not Feasible
Produce Enzyme On-site
Fibre + Bark
c/w Labour
w/o Labour
6.929
6.929
0.580
0.580
1.310
1.310
0.733
0.733
0.021
0.021
0.769
0.769
1.412
1.412
0.230
0.230
0.368
0.368
1.506
1.506
0.601
0.122
1.175
1.175
0.574
1.053
12.06
6.58