1. Pyrolysis of Switchgrass
Amanda Drabek & Kang-Lih Chey

2. Introduction
Bio-Oil Components:
Bio-Oil
Switchgras s

3. Goals of this Project
Design pyrolysis process to convert switchgrass to bio-oil and upgrade to liquid fuel.
Determine factors that would make process economical.

4. Upgrading Options Upgrade bio-oil using hydrotreating process
Upgrade bio-oil using catalytic deoxygenation
Consider 5 different scenarios.

5. Design Pyrolysis Process

6. Lab Scale Pyrolysis Reactor System
“Bench-Scale Fluidized-Bed Pyrolysis of Switchgrass for Bio-Oil Production.” Boateng, et. al. Ind. Eng. Chem. Res

7. Industrial Scale Pyrolysis Process
Units = Metric Tons/hr
Energy Required for the Pyrolysis Process: 81,812 MJ
Energy Supplied by Char: 252,000 MJ
Switchgrass 100

8. Selecting Reactor Type
Use fluid bed reactor.

9. Optimum Reactor Temperature
Reactor Temperature is 480 °C

10. Plant Location Build the plant in Iowa
Centrally located in Midwest
Research currently being done in Iowa regarding switchgrass
20 acres of land for biofuels plant
Cost of land in Iowa is $5140 per acre
Total cost of land for the plant is $102,800

11. Transportation Costs
Transportation is $0.10 per ton switchgrass per mile
Plant based on 100 tons/hr switchgrass feed
Transportation cost is $860 per hr

12. Upgrading Option 1: Hydrotreating

13. Hydrotreating Overview
Reacts hydrogen with bio-oil to remove oxygen.
Hydrogen is produced from steam reformer.
Steam reformer uses NCG and additional methane as feed.

14. Hydrotreating Economic Summary
Equipment Cost
(in millions)
Pyrolysis unit
$1.20
Hydrotreater
$5.00
Steam Reformer
$0.69
Land (acres)
$0.10
Total Equipment Costs
$6.99
Direct Costs
Purchased equipment
Purchased-equipment installation
$3.29
Instrumentation and controls
$2.52
Piping
$4.76
Electrical systems
$0.77
Buildings
$1.26
Yard improvements
$0.70
Service facilities
$4.89
Total Direct Costs
$25.17
Indirect Costs
Engineering and supervision
$2.31
Construction expenses
$2.87
Legal expenses
$0.28
Contractor's fee
$1.54
Contingency
$3.08
Total Indirect Costs
$10.07
Fixed Capital Investment
$35.24
Working Capital
$6.22
Total Capital Investment
$41.47
TCI = $41.5 million
Manufacturing Cost = $157.7 million/yr
Net Profit first year = -$13.73 million
ROI = -0.33

15. Break Even Points Analysis
Break even Oil Price: $119/bbl
Break even Feed Rate: 165 ton/hr

16. Hydrotreating: Optimized Process
Raise product price to $119/bbl
Increase scale to 500 tons/hr feed
Optimized Net Profit: $200 million
Optimized ROI: 4.8
Conclusion: Not significant ROI

17. Conclusion from Hydrotreating Method
Not likely to be profitable.
Need to operate at a large scale because of high capital investment.
No significant factor that can be manipulated.
Efficiency of process is not likely to be improved.

18. Upgrading Option 2: Catalytic Deoxygenation

19. Catalyst Chosen: HZSM-5 Zeolite
Produces mostly aromatic products.
Produces an organic and aqueous layer which is easily separable.
Stable at high temperatures.
wireframe representation of the structure of zeolite ZSM-5, where the tetrahedral (silicon or aluminum) atoms sit at the vertices and the red wires represent Si-O-Si or Si-O-Al linkages. The dotted blue lines show the boundaries of the unit cells.

20. Octane Numbers of Upgraded Oil
Chemical
% wt. fraction
Octane #
Benzene
1.2
101
Toluene
3.1
114
Ethylbenzene
2.6
115.5
1,3-dimethylbenzene
9.4
145
Propylbenzene
0.2
127
1,2,4-trimethylbenzene
11.8
136
Butylbenzene
0.3
97.5
2-methylphenol
3.3
---
1-Methyl-4-benzene
2.4
1,2,3,5-tetramethylbenzene
0.5
100
Naphthalene
6.2
Not a component in today’s liquid fuel.
Methylnaphthalene
9.2
1-ethylnaphthalene
3.4
2,3-dimethylnaphthalene
6.3
Methylanthracene
Dimethylanthracene
Components found in today’s fuel.
High octane numbers.
Components NOT found in today’s fuel.
Niche market for Naphthalene.

21. Boiling Points of Upgraded Oil
Chemical
% wt. fraction
Boiling Point (oF)
Benzene
1.2
176.18
Toluene
3.1
231.1
Ethylbenzene
2.6
277.1
1,3-dimethylbenzene
9.4
358
Propylbenzene
0.2
318.6
1,2,4-trimethylbenzene
11.8
336.9
Butylbenzene
0.3
361.9
2-methylphenol
3.3
359.3
1-Methyl-4-benzene
2.4
394
1,2,3,5-tetramethylbenzene
0.5
388.4
Naphthalene
6.2
424.3
Methylnaphthalene
9.2
472.3
1-ethylnaphthalene
3.4
496.9
2,3-dimethylnaphthalene
6.3
511.3
Methylanthracene
646.1
Dimethylanthracene
Expected to be above the methylantracene.
Can separate components based on boiling points.
Can remove Benzene and Toluene if desired.

22. Catalytic Deoxygenation Process
Units = Metric Tons/hr
Total Energy Produced – Total Energy Required = Energy Remaining – = MJ

23. Catalytic Deoxygenation Economics
Equipment Costs
(in millions)
Pyrolysis unit
$1.20
Cat Reactor
$0.67
regenerator
$1.63
storage tank
$0.04
separator
$0.07
land (acres)
$0.10
Total Equipment Cost
$3.72
Direct Costs
Purchased equipment
Purchased-equipment installation
$1.75
Instrumentation and controls
$1.34
Piping
$2.53
Electrical systems
$0.41
Buildings
Yard improvements
$0.37
Service facilities
$2.60
Total Direct Costs
$13.39
Indirect Costs
Engineering and supervision
$1.23
Construction expenses
$1.52
Legal expenses
$0.15
Contractor's fee
$0.82
Contingency
$1.64
Total Indirect Costs
$5.36
Fixed Capital Investment
$18.75
Working Capital
$3.31
Total Capital Investment
$22.06
TCI = $22.91 million
Manufacturing Cost = $121 million/yr
Net Profit first year = -$3.24 million
ROI = -0.15

24. Break Even Points Analysis
Break even Oil Price: $110/bbl
Break even Feed Rate: 66 tons/hr

25. Upgrade Bio-Oil using Cat. Deox.
Break even Catalyst Price: $996/ton
Current Price: $1320/ton
We believe that the catalyst price will decrease when produced in bulk.

26. Alternate Scenarios Scenario 0: original scenario
Scenario 1: Decrease amount of catalyst used from 17 g cat/g oil/min to 8.5 g cat/g oil/min
Scenario 2: Regenerate catalyst 10 times instead of 2; run on 30 minute cycles instead of hour cycles.
Scenario 3: Increase Yield of Product Oil to 23 wt %.
Scenario 4: Process is separate from refinery; add separation process and transportation costs

27. Comparing Alternate Scenarios: Oil Price
Want to sell oil for cheapest price.
Scenarios 1 and 2 are best.

28. Comparing Alternate Scenarios: Plant Size
Plant size is similar across all scenarios except 4.

29. Comparing Alternate Scenarios: Catalyst Price
Want to breakeven with highest catalyst price.
Scenario 2 is best.

30. Catalytic Deoxygenation: Optimized Process
Use Scenario 1 as basis
Increase oil price to $110/bbl
Increase scale to 500 ton/hr
Optimized Net Profit: $170 million
Optimized ROI: 7.8
Conclusion: Significant ROI

31. Conclusions from Scenarios
Scenarios 1 & 2 are most economical.
Scenario 1: Use less catalyst.
Scenario 2: Use catalyst for more cycles.
Optimized scenario gives reasonable ROI
Should combine process with refinery.
Want to increase selectivity of catalyst.

32. Components of Upgraded Bio-Oil
Chemical
% wt. fraction
Octane #
Benzene
1.2
101
Toluene
3.1
114
Ethylbenzene
2.6
115.5
1,3-dimethylbenzene
9.4
145
Propylbenzene
0.2
127
1,2,4-trimethylbenzene
11.8
136
Butylbenzene
0.3
97.5
2-methylphenol
3.3
---
1-Methyl-4-benzene
2.4
1,2,3,5-tetramethylbenzene
0.5
100
Naphthalene
6.2
Not a component in today’s liquid fuel.
Methylnaphthalene
9.2
1-ethylnaphthalene
3.4
2,3-dimethylnaphthalene
6.3
Methylanthracene
Dimethylanthracene
Want to increase selectivity for blue and purple components because they are found in today’s fuel.

33. Proposed Experiments
Determine how many times can you regenerate the catalyst for a set run time.
Determine minimum amount of catalyst that can give a desirable product.
Increase selectivity of catalyst for liquid product.

34. Conclusions Pursue Catalytic Deoxygenation method For catalyst:
Decrease amount used
Increase selectivity
Scenario
TCI
(million $)
Net Profit (million $)
ROI
Hydrotreating
$41.5
-$13.73
-0.33
Cat. Deox. Original
$22.06
-$3.24
-0.15
Cat. Deox. 1
$10.09
0.46
Cat. Deox. 2
$8.24
0.37
Cat. Deox. 3
$10.07
Cat. Deox. 4
-$24.32
-1.06

35. Questions?

36. Reactor Types
Fluidized Bed
Circulating Fluidized Bed
Ablative