Making beer takes water. Lots of water. And the water that doesn’t end up as part of the brew ends up as a slurry of leftover malted grains and yeast. That can mean high clean-up costs, as well as wasted water. To Hong Liu, it means energy.
Liu has developed a microbial fuel cell that can help brewers reduce water use and produce electricity by processing wastewater. And it’s not just brewers who are interested in this new technology.
Liu, a professor in OSU’s Department of Biological and Ecological Engineering, has developed an improved technology that harnesses the power of microbes to produce electricity directly from wastewater. The technology could create waste treatment plants that power themselves.
Liu’s work with microbial fuel cells has been powered by state and federal grants that connect basic science and commercialization of innovative ideas. Support from the National Science Foundation and Oregon BEST, the agency that promotes the state’s cleantech industry, led to Liu’s founding the start-up company Waste2Watergy, with Yanzhen Fan, a previous fellow OSU researcher.
A project with Widmer Brothers Brewing is the first pilot-test of their new technology. “We chose to partner with Widmer because they are very engaged in sustainability efforts, their wastewater has an ideal mix of organic materials for our technology, and they are very interested in reducing wastewater costs,” Liu said. Waste2Watergy has installed a 1-cubic meter fuel cell at Widmer’s Portland brewery to treat about 1,000 gallons a day while generating electricity at the same time.
These new developments in fuel cell technology could save food and beverage companies millions of dollars in water treatment costs. Liu’s aspirations for Waste2Watergy reach even farther, to developing nations where access to electricity and sewage treatment is lacking. Microbial fuel cells could provide an efficient, low-cost way of treating wastewater while providing off-the-grid communities with electricity for lights or charging cell phones.
Microbial fuel cells use microbes to oxidize organic matter in wastewater, which in turn produces electrons. These electrons Technology transfer brews beer and energy flow from the fuel cell’s anode to its cathode, creating an electrical current. Liu’s new microbial fuel cell has reduced the anodecathode spacing and uses proprietary separator and electrode materials to increase the amount of energy produced from the organic matter. As a result, the new fuel cell—using organic matter from grass straw, animal waste, or byproducts from food and beverage industries—produces electricity more efficiently than do anaerobic digesters and treats wastewater more effectively.
“If this technology works on a commercial scale, the treatment of wastewater could be a huge energy producer, not a huge energy consumer,” Liu said.