Energy 101 - Renewables

Cellulosic Ethanol

While ethanol is typically produced from the starch contained in grains such as corn and grain sorghum, it can also be produced from cellulose. Cellulose is the main component of plant cell walls and is the most common organic compound on earth. It is more difficult to break down cellulose to convert it into usable sugars for ethanol production. Yet, making ethanol from cellulose dramatically expands the types and amount of available material for ethanol production. This includes many materials now regarded as wastes requiring disposal, as well as corn stalks, rice straw and wood chips or "energy crops" of fast-growing trees and grasses.

Producing ethanol from cellulose promises to greatly increase the volume of fuel ethanol that can be produced in the U.S. and abroad. A recent report found the land resources in the U.S. are capable of producing a sustainable supply of 1.3 billion tons per year of biomass, and that 1 billion tons of biomass would be sufficient to displace 30 percent or more of the country's present petroleum consumption. Importantly, it offers tremendous opportunities for new jobs and economic growth outside the traditional "grain belt," with production across the country from locally available resources. Cellulose ethanol production will also provide additional greenhouse gas emissions reductions. Building upon the strong foundation grain-based ethanol technology has provided, the ethanol industry is rapidly developing and expanding the number of feedstocks available for ethanol production.

Iogen Corporation in Ottawa, Canada produces just over a million gallons annually of cellulose ethanol from wheat, oat and barley straw in their demonstration facility. In late 2007, Range Fuels broke ground on a 20 million gallon per year facility that will process ethanol from wood and wood waste in Georgia. Several existing ethanol plants in the U.S. are engaged in research and demonstration projects with the U.S. Department of Energy utilizing the existing fiber in their facility that typically goes into the livestock feed coproduct. Enzyme companies including Genencor International and Novozymes are working on research projects with the Department to significantly reduce enzyme cost and increase enzyme life and durability. With continued advancements in pretreatment technology, fermentation, and collection and storage logistics, the commercial production of cellulose ethanol becomes more economically feasible.