Researchers create fuel mix using electrolyzed water, DDGS

By Hope Deutscher | August 10, 2009
Report posted on Aug. 10, 2009 at 4:12 p.m. CST

Researchers at the University of Illinois have found that using electrolyzed water, rather than harsh chemicals, may be more effective and environmentally friendly in pretreating distillers dried grains with solubles (DDGS) to produce an acetone-butanol-ethanol fuel mix.

Researchers, led by Hao Feng, a University of Illinois food scientist, are searching for ways to extract the sugar from DDGS and ferment it to produce an acetone-butanol-ethanol fuel mix. "We want to utilize the carbon in the DDGS to produce fuels," Feng said. "Right now there are a whole bunch of different methods to treat biomass. We want to find some new methods."

The National Research Initiative of the USDA Cooperative State Research, Education and Extension Service and the U.S. DOE are supporting the research.

One obstacle that the researchers encountered was in the pretreatment phase. "For any biofuel production you need to have simple sugars such as glucose," Feng said. The glucose in DDGS is stuck together, forming cellulosic corn fiber, but the structure is very tough. It forms a kind of crystalline structure which is very difficult to break, he added. "In order to get the glucose out, we need to somehow destroy the structure. Normally people use a strong acid such as sulfuric acid, or a strong lime base, to loosen it, making holes in it. Once the structure is destroyed, we use enzymes to cut the chain of glucose to get glucose that can be used for fermentation." However, Feng said destroying the structure with chemicals produced compounds that were not friendly to the microorganisms used in fermentation.

Feng has been using electrolyzed water in his lab to kill bacteria and other bugs such as E. coli on fresh fruits and vegetables. With electricity, the water is split into two properties - one is acidic, the other is alkaline, he said. Realizing that these similar properties in sulfuric acid and lime are used to pretreat DDGS in fuel production, the University of Illinois scientists experimented to compare the use of electrolyzed water to the traditional chemicals. Feng said the researchers found that when they used the strong sulfuric acid method there was no fuel produced. "The toxic compounds killed the microbes that produce acetone-butanol-ethanol mix completely," he said. "But using acidic electrolyzed water, at about 20 hours the fermentation process began producing the acetone-butanol-ethanol mix. This is an example of less inhibitor production with electrolyzed water compared with the traditional method."

The new technique also eliminated a production step, Feng said. "With the traditional acid method they have to remove the toxicity. With electrolyzed water, there is no need for this detoxification, so this process should be more economical as well. The other advantage of this method is that the traditional method produces a large quantity of solid waste that needs to be handled, and some sugars get consumed in the process as well. We want to maximize the sugar yield so we can maximize the ethanol yield," he said

The researchers have successfully tested the process on a small laboratory scale, now Feng said they need to look at the economic feasibility of the process to move increase it to pilot scale.

Some of the results from the study are published in a 2009 issue of American Society of Agricultural and Biological Engineers.