U.S. Department of Energy - Energy Efficiency and Renewable Energy
ZeaChem Breaks Ground on a Cellulosic Ethanol Biorefinery in Oregon
June 9, 2010
ZeaChem, Inc. held a groundbreaking ceremony on June 2 for a new cellulosic ethanol biorefinery in Boardman, Oregon. Cellulosic ethanol is ethanol produced from non-edible biomass sources, such as agricultural residues, trees, or grasses. The demonstration-scale facility will produce 250,000 gallons per year of ethanol from hybrid poplar trees grown at a nearby tree farm, but it will also test the production of ethanol from other biomass sources, such as agricultural residues and herbaceous crops. The ZeaChem technology uses a chemical process to separate the sugars (xylose and glucose) from the biomass, then uses a bacteria to ferment the sugars, forming acetic acid. The acetic acid is then concentrated and chemically converted into ethyl acetate. While ethyl acetate is itself a marketable chemical product, ZeaChem intends to use a $25 million grant, awarded by DOE through the American Recovery and Reinvestment Act, to add the capability of converting the ethyl acetate into ethanol.
To accomplish that trick requires several additional steps. First, the residues left over after the sugars are separated from the biomass will be fed into a high-temperature gasifier, forming a hydrogen-rich synthetic gas, or "syngas." The hydrogen will be separated from the syngas and reacted with the ethyl acetate to form ethanol. Meanwhile, the remaining syngas will be burned to create steam and power for the biorefinery. As a result, the facility will have the capability to produce multiple products: a marketable biobased chemical, cellulosic ethanol, and electrical power. ZeaChem expects the steam and power produced to be essentially equal to the energy demands of the biorefinery. The company also claims that the facility could be modified to produce a variety of biobased organic chemicals, allowing the company to change its product to best respond to market conditions.
ZeaChem expects the facility to begin operating this year using its core technology for ethyl acetate production, with cellulosic ethanol production starting in 2011. The company has tested its fermentation technology at a research facility in Colorado, and it claims that numerous industry vendors have validated the additional process steps, include acetic acid concentration and ethyl acetate production. The Oregon Employment Department calculates that construction and operation of the Boardman facility will create 292 direct and indirect jobs in Oregon. See the ZeaChem press release and the technology description on the ZeaChem Web site.