Xethanol Corporation has formed a venture with Renewable Spirits, LLC for the purpose of building a biomass-based pilot production facility that will utilize waste citrus peels as feedstock for ethanol production. The venture is located in Bartow, Florida, the heart of the state’s citrus industry.
Citrus waste is rich in pectin, cellulose and hemicellusic polysaccharides, which can be hydrolyzed into sugars and fermented into ethanol. In Florida alone, citrus processing yields about 5 million tons of wet waste annually, or about 1.2 million tons of dry waste, most of which is currently marketed as low-value feed for cattle. A citrus-to-ethanol process could yield up to 80 million gallons of ethanol per year just from Florida citrus waste, according to the US Department of Agriculture (USDA).
The venture is expected to establish a pilot plant to produce up to 50,000 gallons of ethanol this harvesting season. The pilot plant, which will increase to more than 500,000 gallons per year, is co-located at a facility owned and operated by Peace River Citrus Products, Inc., a leading producer of orange and grapefruit juice and other citrus products.
Slated to begin production by the second quarter of 2007, the program plans to utilize a production technology process, developed through a Cooperative Research and Development Agreement (CRADA) with the USDA that will convert waste citrus biomass into ethanol, as well as other marketable co-products, such as limonene and citrus oil, to improve the economics of fuel production.
USDA work on the producing ethanol from peels began in 1992, but was shelved due to the low cost of gasoline and the use of other oxygenates (such as MTBE) within gasoline. In 2004, however, Bill Widmer, an ARS chemist at Winter Haven, modified the process to reduce substantially the amount of enzyme required to convert citrus-waste carbohydrates to the sugars which serve as the fermentation feedstock for ethanol. His project was partly funded by Renewable Spirits. (Earlier post.)
In building the pilot production facility, Xethanol will utilize equipment and production processes from its Permeate Refining test facility in Cedar Rapids, Iowa. This facility had been a pilot plant for testing various sugar based feedstocks, and the lessons learned and processing techniques from its operation will be applied to the new citrus project. The inclusion of the Permeate equipment will allow the Company to evaluate and maximize this technology in a much timelier manner.
We are extremely proud to be partnering with leading scientists from the USDA to extend their breakthrough work into the pilot production phase.—David Ames, president and CEO of Xethanol
Renewable Spirits, an investor group, has spent the last two years working with the USDA to develop the technology used in the pilot plant, and has been successful in removing limonene from the peel, allowing for the fermentation of the sugars in the peel and batch distillation of ethanol at the USDA laboratory in Winter Haven, FL. USDA scientists say this is the first facility of its kind.