One of the attractions of biofuels is they can be used in most internal combustion engines with little or no modification. Ethanol and biodiesel are the two most immediate candidates for adoption into the existing petroleum fuel infrastructure. For decades, ethanol has been used alone and with petroleum-based gasoline in internal combustion engines. Now, the renewable nature of its feedstocks has focused national attention and government assistance on ethanol as a renewable fuel. Present U.S. ethanol production is primarily by the bioconversion of the grain from corn and wheat, and in some instances, sugarcane.
Current grain-based ethanol production systems are an obvious first step in developing an agricultural-based industrial sector that addresses part of our national biofuel need. The industry is based on existing and proven crop production and transportation infrastructure models as well as a proven, workable fermentation production technology. However, grain-based production is limited by available grain feedstocks and their prices as valuable multi-use commodities. Any way to increase the efficiency of the grain-based processing systems increases their profitability for their owners and investors.
For this reason, research engineers and industrialists have sought to make conventional, grain-based ethanol systems more efficient by not just fermenting (fermentation processing) the grain, but by bioprocessing as much of the plant (cellulose and hemicellulose) as possible. This technology looks to digest (enzymatic digestion) much of the plant into usable subunits that can then be efficiently converted (bio-catalysis) to sugars for fermentation processing. The less usable co-products (lignin, ash and hard-to-process proteins) can be combusted to provide power and heat for the ethanol production facility and the residual non-combustible ash and gypsum can become a marketed co-product for field fertilizer. This is the basic system envisioned for cellulosic ethanol production. Cellulosic (plant fiber) "conversion," along with hydrogen, is viewed by many environmental and social policy organizations as being the transportation fuel future of the United States, if not the world. November 2010 . . . Cellulosic Ethanol
- Biofuels in the U.S. Transportation Sector, Energy Information Administration, 2007.
- Cellulosic Biofuels: Analysis of Policy Issues for Congress, Congressional Research Service, 2010.
- Cellulosic Energy Fact Sheet, National Commission on Energy Policy Forum, The Future of Biomass and Transportation Fuels; Dartmouth College, Carnegie Mellon University and Natural Resources Defense Council; National Commission on Energy Policy; 2003.
- Cellulosic Ethanol, National Renewable Energy Laboratory (NREL), 2007 - Overview of national research into cellulosic ethanol.
- Cellulosic Ethanol, Renewable Fuels Association - Cellulosic ethanol review.
- Cellulosic Ethanol, State Energy Conservation Office.
- Converting Cellulose Into Ethanol and Other Biofuels, Ethanol Across America, 2009 - More than two dozen different companies are engaged in nearly 100 projects to produce cellulosic biofuels, with encouraging signs that federal requirements for these fuels can be met.
- Ethanol, Biomass Program, U.S. Department of Energy.
- Feasibility Assessment Template for an Enzymatic Hydrolysis Lignocellulosic Ethanol Plant, Oklahoma State University, 2008 - This tool is designed to assess the feasibility of building an ethanol plant. Users may input such key information as plant capacity, feedstock, equipment costs and personnel and then perform a sensitivity analysis, thus determining how plant profits will be affected by internal and external changes. A guide to using the template is provided.
- Next-Generation Biofuels: Near-Term Challenges and Implications for Agriculture, Economic Research Service, USDA, 2010 - This report assesses the short-term outlook for production of next-generation biofuels and the near-term challenges facing the sector.
- Principles for Bioenergy Development, Union of Concerned Scientists, 2007.
- U.S. Baseline Briefing Book, Food and Agricultural Policy Research Institute (FAPRI), University of Missouri and Iowa State University, 2010 - Assuming some reductions in production, collection and processing costs, FAPRI expects cellulosic ethanol production to expand rapidly after 2015.
Will Cellulosic Ethanol Take Off?, Technology Review Inc., Massachusetts Institute of Technology, 2007 - With government assistance, fuel from grass and wood chips could be realized in ten years.
Links checked January 2013.