Future Prospects of Cellulosic Ethanol
As of mid 2013, several indicators have shown a steady progress in the cellulosic ethanol industry, even though the earlier targets set in the United States have not been met, as expected. Technoeconomic analysis plays an important role in the realization of cellulosic ethanol. The overreaching goal for the DOE’s office of the biomass program is to demonstrate the cost-competitiveness of cellulosic ethanol with petroleum fuels. The 2011 NREL report on development targets predicted an nth-plant MESP of $2.15/ gal by 2012, as modeled by the NREL process design for a corn stover-acid pretreatment-enzyme hydrolysis plant [2]. This MESP value is comparable to current gasoline prices in the US, since a kilogram of ethanol has about 66% of the energy in a kilogram of gasoline. With continuous R&D efforts in enzyme technologies and energy efficient processing configurations, MESP value is expected go below $2.00/gal in the coming years, boosting investor confidence.
The cellulosic biofuel industry 2012-2013 progress report is a more realistic and a vital indicator, which summarizes the global perspective of the industry [30]. This report gives a detailed snapshot of advancements made towards the commercial deployment of cellulosic ethanol. According to Sandia National Lab and the cellulosic biofuel industry 2012-2013 progress report, the United States could produce 75 billion gallons of cellulosic ethanol without displacing food and feed crops [30]. For comparison, the US consumed 134 billion gallons of gasoline in 2011. According to the advanced ethanol council’s 2012-2013 progress report, there are about ten commercial-scale (>20 million gallons/year) cellu — losic ethanol plants in operation or under construction around the world in 2013 [30]. Of course this is a very small fraction in comparison with first generation corn ethanol production capacity in the United States, which is 13.9 billion gallons/year in 2011 [31]; clearly, cellulosic ethanol is an industry in its infancy. However, entering into a commercial operation phase is an encouraging sign and a testimony for investor confidence on cellulosic ethanol technology. The future of cellulosic ethanol looks promising and the goal of large-scale production of fuel ethanol from abundant lignocellulosic biomass to meet the global energy demand is realizable in the near future.
1. L. Tao and A. Aden, The economics of current and future biofuels. In Vitro Cellular and Developmental Biology — Plant, 2009. 45(3): p. 199-217.
2. R. D. D. Humbird, L. Tao, C. Kinchin, and a. A.A. D. Hsu, Process design and economics for biochemical conversion of lignocellulosic biomass to ethanol dilute-acid pretreatment and enzymatic hydrolysis of corn stover, 2011, NREL.
3. F. Kabir, J. Fortman, R. P. Anex, D. D. Hsu, A. Aden, A. Dutta, G. Kothandaraman, and R. E. Brown. Techno-economic comparison of biochemical processes for ethanol production from lignocellulosic feedstock. 2009.
4. F. K. Kazi, J. A. Fortman, R. P. Anex, D. D. Hsu, A. Aden, A. Dutta, and G. Kothandaraman, Techno-economic comparison of process technologies for biochemical ethanol production from corn stover. Fuel, 2010. 89, Supplement 1(0): p. S20-S28.
5. L. Tao, A. Aden, R. T. Elander, V. R. Pallapolu, Y. Y. Lee, R. J. Garlock, V. Balan, B. E. Dale, Y. Kim, N. S. Mosier, M. R. Ladisch, M. Falls,
M. T. Holtzapple, R. Sierra, J. Shi, M. A. Ebrik, T. Redmond, B. Yang, C. E. Wyman, B. Hames, S. Thomas, and R. E. Warner, Process and technoeconomic analysis of leading pretreatment technologies for lignocellulosic ethanol production using switchgrass. Bioresource Technology, 2011. 102(24): p. 11105-11114.
6. L. Tao, X. Chen, A. Aden, E. Kuhn, M. E. Himmel, M. Tucker, M. A.A. Franden, M. Zhang, D. K. Johnson, N. Dowe, and R. T. Elander, Improved ethanol yield and reduced minimum ethanol selling price (MESP) by modifying low severity dilute acid pretreatment with deacetylation and mechanical refining: 2) Techno-economic analysis. Biotechnology for Biofuels, 2012. 5.
7. J. D. Stephen, W. E. Mabee, and J. N. Saddler, Will second-generation ethanol be able to compete with first-generation ethanol? Opportunities for cost reduction. Biofuels, Bioproducts and Biorefining, 2012. 6(2): p. 159-176.
8. Q. Jiang, Y. Q. Sun, H. Teng, Z. L. Xiu, and C. Z. Liu, Techno-economic analysis of cellulosic ethanol. Guocheng Gongcheng Xuebao/The Chinese Journal of Process Engineering, 2012. 12(1): p. 97-104.
9. S. R. Tewfik, M. H. Sorour, A. M.G. Abulnour, H. A. Talaat, N. R. Mitry,
N. M. H. Eldefrawy, and S. A. Ahmed. Techno-economic investigations on the small-scale production of ethanol from egyptian rice straw. 2010.
10. C. Piccolo and F. Bezzo, A techno-economic comparison between two technologies for bioethanol production from lignocellulose. Biomass and Bioenergy, 2009. 33(3): p. 478-491.
11. H.-J. Huang, S. Ramaswamy, W. Al-Dajani, U. Tschirner, and R. A. Cairncross, Effect of biomass species and plant size on cellulosic ethanol: A comparative process and economic analysis. Biomass and Bioenergy, 2009. 33(2): p. 234-246.
12. R. M. Aden A, Ibsen K, Jechura J, Neeves K, Sheehan J, Lignocellulosic biomass to ethanol process design and economics utilizing co-current dilute acid prehydrolysis and enzymatic hydrolysis for corn stover. National Renewable Energy Laboratory report no. NREL/TP-510-32438, 2002.
13. E. Sendich, M. Laser, S. Kim, H. Alizadeh, L. Laureano-Perez, B. Dale, and L. Lynd, Recent process improvements for the ammonia fiber expansion (AFEX) process and resulting reductions in minimum ethanol selling price. Bioresource Technology, 2008. 99(17): p. 8429-8435.
14. M. Laser, E. Larson, B. Dale, M. Wang, N. Greene, and L. R. Lynd, Comparative analysis of efficiency, environmental impact, and process economics for mature biomass refining scenarios. Biofuels, Bioproducts and Biorefining, 2009. 3(2): p. 247-270.
15. E. Gnansounou and A. Dauriat, Techno-economic analysis of ligno — cellulosic ethanol: A review. Bioresource Technology, 2010. 101(13): p. 4980-4991.
16. B. Bals, C. Wedding, V. Balan, E. Sendich, and B. Dale, Evaluating the impact of ammonia fiber expansion (AFEX) pretreatment conditions on the cost of ethanol production. Bioresource Technology, 2011. 102(2): p. 1277-1283.
17. D. Klein-Marcuschamer, P. Oleskowicz-Popiel, B. A. Simmons, and H. W. Blanch, Technoeconomic analysis of biofuels: A wiki-based platform for lignocellulosic biorefineries. Biomass and Bioenergy, 2010. 34(12): p. 1914-1921.
18. NAS, National Academy of Sciences. Liquid Transportation Fuels from Coal and Biomass: Technological Status, Costs, and Environmental Impacts. Washington, DC: The National Academies Press, 2009, 2009.
19. A. Dutta, M. Talmadge, J. Hensley, M. Worley, D. Dudgeon, D. Barton, P. Groenendijk, D. Ferrari, B. Stears, E. Searcy, C. Wright, and J. R. Hess, Techno-economics for conversion of lignocellulosic biomass to ethanol by indirect gasification and mixed alcohol synthesis. Environmental Progress and Sustainable Energy, 2012. 31(2): p. 182-190.
20. A. Dutta. Techno-economic study of the production of mixed alcohols from lignocellulosic biomass using direct gasification. 2008.
21. P. Ollero, P. Haro, A. Villanueva, C. Reyes, J. Caraballo, and J. Antonio Redondo. Technoeconomic assessment of an innovative thermochemical route to produce ethanol from lignocellulosic biomass. 2011.
22. A. L. Villanueva Perales, C. Reyes Valle, P. Ollero, and A. Gomez — Barea, Technoeconomic assessment of ethanol production via thermochemical conversion of biomass by entrained flow gasification. Energy, 2011. 36(7): p. 4097-4108.
23. J. E.A. Seabra, L. Tao, H. L. Chum, and I. C. Macedo, A techno-economic evaluation of the effects of centralized cellulosic ethanol and co-products refinery options with sugarcane mill clustering. Biomass and Bioenergy, 2010. 34(8): p. 1065-1078.
24. P. Haro, P. Ollero, A. L. Villanueva Perales, and A. Gomez-Barea, Thermochemical biorefinery based on dimethyl ether as intermediate: Technoeconomic assessment. Applied Energy, 2013. 102: p. 950-961.
25. P. Haro, P. Ollero, A. L. Villanueva Perales, and C. Reyes Valle, Technoeconomic assessment of lignocellulosic ethanol production via DME (dimethyl ether) hydrocarbonylation. Energy, 2012. 44(1): p. 891-901.
26. A. Dutta, R. L. Bain, and M. J. Biddy, Techno-economics of the production of mixed alcohols from lignocellulosic biomass via high-temperature gasification. Environmental Progress and Sustainable Energy, 2010. 29(2): p. 163-174.
27. J. Hu, Y. Wang, C. Cao, D. C. Elliott, D. J. Stevens, and J. F. White, Conversion of biomass-derived syngas to alcohols and C2 oxygenates using supported Rh catalysts in a microchannel reactor. Catalysis Today, 2007. 120(1): p. 90-95.
28. R. Stevens, Dow Chemical Company, assignee. Process for producing alcohols from synthesis gas. US Patent Nov. 21., 1989: United States.
29. S. J. G Prieto, Martinez A, Sanz JL, Caraballo J, Arjona R, Abengoa Bioenergias Nuevas Tecnologias S. A, assigneee. Method for obtaining a multimetallic sulfureous catalyst and use thereof in a method for producing higher alcohols by catalytic conversion of synthesis gas. Spanish Patent. International publication number: ; 2011 March, 2011, Abengoa Bioenergias Nuevas Tecnologias.
30. AEC, Cellulosic biofuels industry progress report 2012-2013, in Advanced Ethanol Council, A. e. council, Editor 2012.
31. REN, Renewables 2012 global status report, 2012, Renewable energy policy network for the 21st century: Paris: REN21 Secretariat.