EPA Scientists Pioneer Methods for Greening Biofuels Production
EPA researchers test new technology to reduce the costs of biofuels production.
Anyone who has filled their car recently understands the growing desire to develop substitutes for gasoline. Biofuels, such as ethanol made from corn and other bio-based feedstocks, have been a highly sought-after potential candidate for years. But while the prospect of turning domestically grown corn crops into fuel is an exciting one, the actual practice has faced significant sustainability challenges.
Using current methods, the production of ethanol consumes a large portion of the energy it yields. Traditional production, relying on a distillation process that separates energy-rich alcohols from dilute fermentation broths, requires the generation of steam, which requires large energy inputs.
EPA researchers Leland Vane, Ph.D. and Franklin Alvarez are working to change that through the development of more energy efficient ways of producing biofuels. The two scientists have pioneered a kind of hybrid distillation method that uses a new membrane technology to produce fuel-grade ethanol with greatly reduced energy and production inputs.
Based on promising bench studies, including process simulations and sophisticated spread-sheeting analysis software, the researchers and their partners are now conducting pilot tests of the new technology. If the new technology continues to show positive results as it is scaled up, it could lead to less expensive, cleaner-burning gas and less dependency on foreign supplies of oil, according to Alvarez.
“By using new membrane technologies, we can produce the same amount of ethanol using about half the amount of energy needed with other processes,” says Alvarez, a chemical engineer in an EPA research lab in Cincinnati, Ohio that explores green chemistry and engineering to advance clean processes and other environmentally sustainable technologies.
The new method Vane and Alvarez are working on employs what they call membrane assisted vapor stripping (MAVS) technology that efficiently separates water from alcohol (fuel). Substituting the MAVS hybrid technology for the distillation process in pilot tests is proving to allow ethanol production using much less energy and production costs than is possible with current methods. The product of the MAVS process is ethanol concentrated to the 99.5 weight percent (wt%) needed if it is to be blended with gasoline.
The new hybrid technology is so efficient and easy to employ, in fact, that it has the potential to make small-scale operations more cost-effective. This would greatly expand the number and amount of bio-based sources that could be turned into ethanol, including waste and byproducts from a host of food processing and other industries.
Alvarez points to interest already expressed from cheese and wine companies seeking to extract energy from whey (a cheese by-product) and grape skins to produce fuels, as well as valuable chemicals they could sell on the open market. “Using the steam stripper and membrane technology allows us to get additional energy out of these waste streams,” he explains. “We are open to working with a variety of companies to transform their waste streams so they are cheaper to dispose of and more environmentally friendly,” he adds.
“Promoting the efficiency of fuel production and reducing environmental waste is a win-win situation for EPA and the private sector. I am proud to be part of a team that takes science and engineering so seriously and is creating a safer country and a cleaner environment,” Alvarez says.
The new EPA technology could clear the way for a more efficient, cost-effective, and environmentally friendly set of solutions to persistent energy challenges facing the nation. It could make a trip to the gas station far less painful.