Alternate Fuel Source Study
DE-FG36-05G085011
Program Feedstock Platform Portfolio Peer Review
August 2007
Ralph H. Zee, PhD
Auburn University
Presentation Outline
•
•
•
•
•
•
•
•
Project Goals and Objectives
Technical Targets
Technical Feasibility and Risks
Accomplishments
Issues Overcome
Looking at Critical Issues
Planning
Summary
Goals and Objectives
• Identify alternative fuel sources and conduct
feasibility tests to replace coal in cement
processing with emphasis on burn mechanics
and properties
• Use an operating cement plant as a model to
understand effects of fuel replacement
• Explore other methodologies of using
alternative fuels
Project Stage
Current
Current Project
Project Stage
Stage
(60%
(60% of
of work
work complete)
complete)
Background: Cement Kilns in US
(Source: Earthjustice)
Background: Lafarge Roberta Cement Plant
(Source: Lafarge NA)
Background: Use of Alternative Fuels in
the Manufacture of Portland Cement
(Source: PCA 2003)
Addition
Addition of
of
Alternative
Alternative Fuels:
Fuels:
Switchgrass
Switchgrass
Wood
Wood wastes
wastes
Broiler
Broiler litter
litter
Scrap-tires
Scrap-tires
Recycled
Recycled Plastics
Plastics
Raw materials are ground, to powder and blended.
Burning changes raw mix chemically into cement clinker.
Background: Use of Alternative Fuels in
the Manufacture of Portland Cement
1400 °C
Use of Scrap Tires as Alternative
Fuel at Roberta Plant, AL
Kiln at Roberta Plant, AL
Typical Temperatures in a Cement Kiln
2000
1800
Material Temperature
1600
1400
1200
1500°C
800
600
400
200
Calciner
1000
Preheater
1400 °C
Gas Temperature
Temperature (°C)
Addition
Addition of
of
Alternative
Alternative Fuels:
Fuels:
Switchgrass
Switchgrass
Wood
Wood wastes
wastes
Broiler
Broiler litter
litter
Scrap-tires
Scrap-tires
Recycled
Recycled Plastics
Plastics
10 s. 3s.
900°C
Rotary Kiln
Cooling
Gas Retention Time
10 s.
1 s.
Material Retention Time
1 min.
30 min.
30 min.
(Source: Mokrzycki and Uliasz-Bocheńczyk, 2003)
Technical Targets
• Utilizing biomass as alternative fuels
• Reducing fuel costs
• Reducing raw materials costs
• Reducing landfill costs
• Reducing environmental pollution
Technical Targets
Sustainability through Alternative Fuels
≈90% Coal
100% Coal
≈10%
Waste Tires
Before
150,000 tons ⇐
Present
⇒
135,000 tons
0 tons ⇐ Alternative Fuel Used / Year ⇒
13,000 tons
Coal Used / Year
Technical Targets
Waste Tires
Recycled Plastics/
Broiler Litter
≈ 10%
≈80% Coal
≈ 20%
≈50% Coal
≈ 10%
≈ 10%
≈ 20%
Waste Tires
Recycled Plastics/
Broiler Litter
Short Term Goal
120,000 tons
28,000 tons
⇐
Switchgrass/
Wood wastes
Long Term Goal
⇒
75,000 tons
⇐ Alternative Fuel Used / Year ⇒
115,000 tons
Coal Used / Year
Environmental Advantages
Environmental Sustainability and Resource
Management
• Broiler litter land application problematic
– Most available sites exceed allowable P
and N
– Cannot be stored indefinitely
– Valuable energy content underutilized
• Plastics/tires stockpiling problematic
– Large volumes of stockpiles in existence
– Valuable energy content underutilized
Project Participants
Alternative Fuel
Supplier
Civil
Eng.
Chem.
Eng.
Auburn
University
Mater.
Eng.
Agric.
Technology
Transfer
Roberta Plant
Systech
Environ. Corp.
Lafarge
North
America
Compton
Consulting
Testing
Feeds
Fuels
Emissions
Cement
Project Approach
• Survey and select alternative fuel sources
• Trial burns at Lafarge North America Roberta Plant, Calera
– Baseline Burns:
• Coal
• Coal + Scrap Tires
– Test Burn: Coal + Scrap Tires + Broiler Litter
– Test Burn: Coal + Scrap Tires + Waste Plastics
– Test Burn: Coal + Scrap Tires + Wood Wastes
– Test Burn: Coal + Scrap Tires + Switchgrass
– Test Burn: Coal + Scrap Tires + 2 Bio fuels
• Examine
–
–
–
–
Composition of fuels, feeds, and product
Efficacy and suitability of fuels
Effect on plant operations
Quality of portland cement produced
Sampling and Analysis
Emissions:
Emissions:
CO,
x,x,SO
SO2,2,
CO,NO
NO
Opacity,
Opacity,VOC
VOC
Cement:
Cement:
Chemical
ChemicalProperties,
Properties,
Physical
PhysicalProperties,
Properties,
Mechanical
MechanicalProperties
Properties
Fuels:
Fuels:
Coal,
Coal,Scrap
ScrapTires,
Tires,
Switchgrass,
Switchgrass,Wood
Wood
wastes,
wastes,Broiler
Broilerlitter,
litter,etc.
etc.
Sampling
and
Analysis
Plan
Concrete:
Concrete:
Fresh
FreshProperties,
Properties,
Mechanical
MechanicalProperties,
Properties,
Durability
DurabilityIssues
Issues
Raw
RawMaterials:
Materials:
Limestone/Clay,
Limestone/Clay,
Flyash,
Flyash,Iron(slag),
Iron(slag),
Gypsum
Gypsum
Cement
CementKiln
Kiln
Dust:
Dust:
• •Raw
RawMaterial
Material
• •By-Product
By-Product
Technical Targets
• Develop Burn Simulator
– Design a laboratory scale system to study burn
properties of fuels
– Develop a system to provide scientific information on the
burn process that are complementary to the information
obtained through plant scale trials
– Construct and test the laboratory scale burn simulation
system at Auburn University
•
Feasibility of Gasification Technologies
– Conduct a gasification feasibility study for a cement
facility to determine the technical and economic
feasibility for gasification of alternative fuels
– Evaluate feasibility based on study
Technical Feasibility and Risks
• Impact of alternative fuels on cement burn
characteristics
• Emissions
• Product quality
• Ease of handling
• Safety and health
Accomplishments
• Trial burns at Cement Plant, Calera, AL
–
–
–
–
–
Base fuels: Coal and coal with waste tires
Effect on plant operations
Analysis of fuels, feeds and product
Efficacy and suitability of fuels
Quality of portland cement produced
• Trial Burns:
–
–
–
–
–
–
–
Coal Only:
Coal + Tires: Base-line burn
Coal + Tires + Waste Plastics
Coal + Tires + Broiler Litter
Coal + Tires + Wood Wastes
Coal + Tires + Switchgrass
Coal + Tires + 2 Biomass fuels
→
→
→
→
→
→
→
Completed in April 2006
Completed in July 2006
Completed in April 2007
Completed in June 2007
To be done in 2007
To be done Nov. 2007
To be done in 2007
Broiler Litter Test Burn
Presentation of Results
Energy Content (BTU/lb)
As Received Energy Content (BTU/lb)
Alternative Fuel Combustion Values
Broiler Litter ≈ 4,900 BTU/lb
(As test by AU)
18000
16000
14000
CPR - Coal
ELR - Coal
ELR - Tires
ELR - Plastics
12000
10000
8000
6000
4000
2000
0
Burn One
CPR = Cement Plant Results
Burn Two
Burn Three
ELR = External Lab. Results
Accomplishments
Alt. Fuel to Total Fuel Replacement Rate (%)
27
C+T: Tires (Avg. = 6.5)
C+T+P: Tires (Avg. = 4.8)
24
C+T+P: Plastics (Avg. = 16.9)
C+T+BL: Tires (Avg. = 1.7)
21
C+T+BL: Litter (Avg. = 6.2)
18
15
12
9
6
3
0
0
12
24
36
48
Duration of Test Burn (hours)
60
72
Accomplishments
CO Emissions (tons/ton clinker x 10 -4)
12
10
8
6
4
C Only (Avg. = 7.68)
C+T: (Avg. = 5.41)
C+T+P: (Avg. = 5.67)
C+T+BL: (Avg. = 5.01)
2
0
0
12
24
36
48
Duration of Test Burn (hours)
60
72
Accomplishments
-3
NOx Emissions (tons/ton clinker x 10 )
1.6
1.2
0.8
0.4
C Only: (Avg. = 0.82)
C+T: (Avg. = 1.21)
C+T+P: (Avg. = 1.05)
C+T+BL: (Avg. = 0.81)
0.0
0
12
24
36
48
Duration of Test Burn (hours)
60
72
Accomplishments
Effect of Alternative Fuels on Production
• The rate of tire replacement was limited by the
development of sulfur buildups in the kiln
• The rate of plastics replacement was limited by the
ability of the system to feed the low density material
• The acquisition costs of the alternative fuels was
significantly lower than coal
Accomplishments
Physical Properties of Cement
0.100
Paste Prism Drying Shrinkage (%)
0.090
0.080
0.070
0.060
0.050
0.040
0.030
0.020
Burn One
Burn Two
Burn Three
0.010
0.0000
0
7
14
21
Drying Age (days)
28
35
Accomplishments
Properties of Concrete Mixture A (water/cement = 0.44)
Concrete Compressive Strength (MPa)
60
50
40
30
20
AUR - Burn One
AUR - Burn Two
AUR - Burn Three
CPR - Burn One
CPR - Burn Two
10
0
0
7
14
21
28
35
42
49
56
63
70
77
84
91
98
Concrete Age (days)
CPR = Cement Plant Results
AUR = AU Results
Accomplishments
Properties of Concrete Mixture B (water/cement = 0.37)
Concrete Compressive Strength (MPa)
70
60
50
40
30
20
AUR - Burn One
AUR - Burn Two
AUR - Burn Three
10
0
0
7
14
21
28
35
42
49
56
63
70
77
84
91
98
Concrete Age (days)
AUR = AU Results
Accomplishments
Properties of Concrete Mixture A (water/cement = 0.44)
Concrete Splitting Tensile Strength (MPa)
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
AUR - Burn One
AUR - Burn Two
AUR - Burn Three
0.5
0.00
0
7
14
21
28
35
42
49
56
63
Concrete Age (days)
70
77
84
91
98
ASTM C 496:
With-in
testResults
repeatability = 14%
AUR
= AU
Accomplishments
Properties of Concrete Mixture B (water/cement = 0.37)
Concrete Splitting Tensile Strength (MPa)
6.0
5.0
4.0
3.0
2.0
AUR - Burn One
AUR - Burn Two
AUR - Burn Three
1.0
0.00
0
7
14
21
28
35
42
49
56
63
Concrete Age (days)
70
77
84
91
98
AUR = AU Results
Accomplishments
• Develop Burn Simulator
– Completed literature review of lab scale fuel analysis
systems and capabilities
– Benchmarked systems that met budget and lab scale
fuel feed rate criteria
– Developed preliminary system designs and equipment
specifications
• Worked with leading lab furnace suppliers
– Prepared suitable laboratory space at Auburn
University
Accomplishments
Burn Simulator
Concept Design
Air
Fuel Particles
Fuel Feed Injection
CCD Video
and Lens
Split Tube
Furnace
Filter
Gas Emissions
Analysis
Quartz
Tube
in
Furnace
Accomplishments
• Feasibility of Gasification Technologies
–Team members met with key gasification
experts and design consultants
• International Applied Engineering (IAE)
• Gas Technologies Institute (GTI)
–The study will determine the technical and
economic feasibility for gasification of alternative
fuels to meet energy needs in a cement
processing environment
Issues Overcome
• Plant and community fears of Avian flu
– Plant and community information sessions
– Letter from authoritative ADEM officials
• Equipment to inject alternative fuels
Looking at Critical Issues
• Processing and burn conditions
• Product quality and correlation with
production
• Cost and availability of alternative fuels
Planning
Work in Progress
• Select wood wastes for test burns. Consider:
– wood chips and sawdust
– Switchgrass
• Continuing analyses of test data collected from
test burns
• Develop and use burn simulator
• Feasibility of gasification technologies
Planning
Task or Subtask
Number
Title - Tasks or Subtasks
Program
Pathway &
Milestones Link
Start Date
Planned
Completion Date
Barriers
Addressed
A
Survey of Alternate Waste Materials
M4.4
1-Aug-05
31-Dec-05
Ft-A; Fm-B
B
Selection of Two Alternate Sources of Fuel
M4.4
1-Sep-05
28-Feb-07
Ft-A; Fm-B
C
Test Two Selected Alternate Sources of Fuel
M4.4
1-May-06
30-Jun-07
Ft-E
C.1
Baseline Burn of Coal Only
M4.4
17-Apr-06
25-Apr-06
Ft-E
C.2
Baseline Burn of Coal Plus Tires
M4.4
7-Jul-06
30-Sep-06
Ft-E
C.3
Test Burn of First Alternate Fuel
M4.4
5-Mar-07
30-May-07
Ft-E
C.4
Test Burn of Second Alternate Fuel
M4.4
26-Mar-07
30-Jun-07
Ft-E
D
Analysis and Initiation of Long-term Concrete Testing
M4.4
1-Jul-06
28-Sep-07
Ft-E
E
Development and testing of a Cement Burn Simulator
M4.4
1-Jan-07
31-Dec-07
Ft-E
E.1
Design and Purchase of the Burn Simulator
M4.4
1-Jan-07
31-Jul-07
Ft-E
E.2
Installation and testing of a Cement Burn Simulator
M4.4
1-Jun-07
31-Dec-07
Ft-E
Three Additional Test Burns with Alternate Sources of Fuel
M4.4
1-Apr-07
30-Sep-07
Ft-E
F.3
Test Burn of Third Alternate Fuel
M4.4
1-Apr-07
30-Jul-07
Ft-E
F.4
Test Burn of Fourth Alternate Fuel
M4.4
1-May-07
21-Aug-07
Ft-E
F.5
Test Burn of Simulatneous Use of Two Alternate Fuels
M4.4
17-May-07
30-Aug-07
Ft-E
M4.4; M4.10; M4.12
1-Jan-07
30-Sep-07
Tt-E; Ft-E
F
G
Feasibility Analysis of Commercially Gasification Technologies
Summary
• Evaluate process for co-burning alternative
wastes
–
–
–
–
Burn efficiency,
Process compatibility
Product quality
Emissions
• Use an operating cement plant as model to
reduce dependence on traditional fuels through
the use of bio fuels such as:
– Broiler litter
– Wood waste
– Switch grass, and mixture of these
• Develop a burn simulator to evaluate the burn
characteristics of many possible fuels