Pyrolysis of Switchgrass

1. Pyrolysis of Switchgrass Amanda Drabek & Kang-LihChey

2. Introduction Bio-Oil Bio-Oil Components: Switchgrass

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. 2007.

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 http://www.unh.edu/p2/biooil/bounhif.pdf

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 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.

20. Octane Numbers of Upgraded Oil 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 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 Remaining252000 – 42000 = 210000 MJ

23. Catalytic Deoxygenation Economics 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 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

35. Questions?

36. Reactor Types Fluidized Bed Circulating Fluidized Bed Ablative