Briefing: Cellulosic Ethanol: A Technology Update

by Carole Abourached* (Advanced Biofuels USA) The Environmental and Energy Study Institute (EESI) recently held a briefing on the technologies involved in commercial cellulosic ethanol production. Cellulosic ethanol is produced from agricultural residues such as corn stover and wheat straw and can be also obtained from organic landfill waste, algae, grasses, and wood. Cellulosic ethanol production has become commercial in the U.S. in 2014 and it is expected that total U.S. production will reach 80 million gallons per year at the end of 2014.
Rob Walther, Director of Federal Affairs, POET, discussed the various environmental benefits of cellulosic ethanol. Cellulosic ethanol production uses agricultural waste and does not compete with food production. Also, it reduces carbon dioxide emissions compared to gasoline and it can be produced from various types of feedstocks which makes it possible to produce it in dry regions. In addition, cellulosic ethanol increases national security in the U.S. because one cellulosic ethanol plant can substitute 1 million barrels of imported oil per year.
Also, ethanol results in a decrease in fuel price ($0.50-$1.1 per gallon). For instance, in mid-September 2014, consumers in Lansing, Michigan were able to save $1.20 per gallon by purchasing gasoline with 10 percent ethanol compared to gasoline without ethanol.
The POET-DSM biorefinery that opened in Iowa in September 2014 was the first facility to start producing cellulosic ethanol commercially in the U.S. It is a joint venture of Royal DSM and POET. The plant uses agricultural waste and produces 25 million gallons of 90 percent emission free fuel. If the market conditions stay favorable in the U.S., the industry will build new cellulosic biofuel plants every 4 - 6 months. Also, it might expand to Brazil, Europe and China.
Chris Standlee, Executive Vice President, Global Affairs, Abengoa Bioenergy, mentioned that the future of renewable energy in the U.S. depends on consistent policy support. Then, he discussed the advantages of their cellulosic ethanol. It can reduce Greenhouse gas (GHG) emissions by 110-129 percent compared to conventional gasoline while sugar cane ethanol can decrease GHG by 61 percent and corn ethanol by 21-38 percent. Cellulosic ethanol plants improve the economy by creating new jobs and by purchasing feedstocks from farmers. Abengoa is one of the largest international ethanol producers operating 14 facilities in the U.S., Europe and Brazil. Abengoa started a new cellulosic ethanol plant in Kansas in mid-October 2014. The plant uses around 350,000 tons of biomass and produces 25 million gallons of ethanol per year. Abengoa plans to expand its production around the world.
Nancy Clark, External Relations Manager, Dupont Industrial Biosciences, re-emphasized that the commercialization of cellulosic ethanol is very advantageous for the economy. The new Dupont commercial-scale plant, located in Nevada, Iowa, is the world largest cellulosic ethanol plant and it will produce 30 million gallons of ethanol per year. The plant will improve the economy by creating 85 permanent jobs and benefiting 500 farmers. Besides using cellulosic ethanol as a fuel, Dupont and Procter & Gamble have recently started a partnership to bring cellulosic ethanol into Tide laundry detergent. If the U.S. reduces renewable volume obligations under the Renewable Fuel Standard, Dupont plans to expand outside the U.S.
Amy Davis, Government Relations Manager, Novozymes North America Inc., said that Novozymes is one of the top producers of industrial enzymes and a world leader in bioinnovation. Novoenzymes opened an advanced manufacturing enzyme facility in Nebraska in 2012 in order to support cellulosic ethanol production. A reduction in renewable volume obligations under the Renewable Fuel Standard has been proposed lately by the Obama administration which led to an expansion of Novozymes outside the U.S.
The Renewable Fuel Standard (RFS), created in 2005 and revised in 2007, aimed at decreasing the U.S. dependence on foreign oil, fuel price and GHG emissions as well as increasing U.S. farm income. The RFS requires that cellulosic biofuels must reach a GHG decrease of 60 percent compared to gasoline. According to the speakers, maintaining the RFS is necessary for the commercialization of their products in the U.S. However, the Obama administration proposed a reduction in renewable volume obligations under the RFS. So, if the RFS is not maintained, the various biofuel companies would have to find markets outside the U.S.
The transportation fuel in the US contains around 10 percent ethanol produced mainly from corn starch. Although cellulosic ethanol production is challenging, it is making fast progress because of the advances in enzymes and catalysts technologies. While corn stover is currently being used to produce commercial cellulosic ethanol, other feedstocks such as cover crops, organic wastes and perennial grasses are being tested.
Presenters emphasized that cellulosic ethanol production benefits not only the economy and environment, but also national security.

* Advanced Biofuels USA contributing author, Carole Abourached, Ph.D. in Biological and Ecological Engineering and Water Resources Engineering, is currently the U.S. Water Partnership Coordinator at World Vision and U.S. Water Partnership.