DDGS-to-cellulosic ethanol process could commercialize rapidly

By Holly Jessen | February 05, 2013

NEAtech, a new energy alternatives company, is searching for financing to further test and commercialize its patented distillers grain-to-cellulosic ethanol process.

The consulting company, which has a joint venture with BBI International, received patent No. 8,288,138 in October. The patent, for conversion of biomass into ethanol, covers a process to turn distillers grains or spent brewers grains into ethanol and other commercial products, such as pelletized fuel, biogas, fertilizer and livestock feed.

The process has been tested extensively at laboratory and bench-scale with the assistance of Novozymes, Danisco and the National Renewable Energy Laboratory, said Mark Yancey, president and CEO of NEAtech. The next step is to demonstrate it works at pilot scale, which could be completed at the National Corn-to-Ethanol Research Center, pending financing.

“The NCERC facility would work perfectly with some minor modifications to produce fermentable sugars,” Yancey said, adding that the testing would include the pretreatment, enzymatic hydrolysis and fermentation steps.

The goal is to confirm the yields already demonstrated at bench scale, complete final engineering and, then begin licensing the process to existing corn-ethanol producers interested in a bolt-on system for cellulosic ethanol production. Yancey, one of the five authors listed on the patent, estimated the pathway to commercialization could be less than one year. “Our feasibility work has shown that it is very viable economically,” he says, adding that wet distillers grains could produce between 10 and 12 percent additional ethanol by fermenting residual starch and corn fiber, also resulting in a higher protein animal feed. A 50 million gallon per year plant could produce 55 to 56 MMgy with the NEAtech technology with no increase in corn consumption.

Work on this project started in 2007, when Yancey and the four other authors worked for BBI International’s engineering and consulting group. “We sat down and looked at, what are the road blocks to commercializing cellulosic ethanol,” Yancey said. “One of those road blocks was, and continues to be, the high cost of pretreatment. Our strategy was to find an easily convertible cellulosic feedstock, and as a consequence, lower the cost of pretreatment and not produce fermentation inhibitors.”

The feedstock that came to the forefront as being easily converted to fermentable sugars and for having little to no fermentation inhibition was spent brewers grains. Yancey knew of its potential because in the mid-1990s he worked at NREL on a cooperative research and development agreement with Coors Brewing Co. to test spent brewers grains for ethanol production. Although it showed promise as an ethanol feedstock, the DOE didn’t provide additional funding because, of the total spent brewers grains available, only about 70 MMgy of ethanol could be produced, Yancey said.

However, converting existing supplies of distillers grains could produce significantly more, at about 1 billion gallons of ethanol a year. “It’s a very, very large market and could easily become one of the largest sources of cellulosic ethanol, very rapidly,” he said. “The ethanol plants are out there, the feedstock is available, we just need to complete the technology demonstration.”