Chemical engineers at Carnegie Mellon have designed a new process to improve the efficiency of corn-based ethanol production. Its key component combines a multi-column system with an energy-recovery network that reduces steam consumption.
"This new design reduces the manufacturing cost for producing ethanol by 11 percent, from $1.61 a gallon to $1.43 a gallon," said Professor Ignacio E. Grossmann, who completed the research with chemical engineering graduate students Ramkumar Karuppiah, Andreas Peschel and Mariano Martin. "This research is also an important step in making the production of ethanol more energy efficient and economical."
Once considered a questionable energy resource, corn-based ethanol is now in high demand. In the United States, 46 percent of gasoline contains some percentage of ethanol. By federal mandate, 5 percent of the nation's gasoline supply must contain some percentage of ethanol by 2012. The design has also contributed to reducing the operating costs of corn-based ethanol plants by more than 60 percent.
To achieve the results, Cargill — an international provider of food, agricultural and risk-management services and products — worked in collaboration with the engineers at the Center for Advanced Process Decision-Making (CAPD) in Carnegie Mellon's Department of Chemical Engineering.
"The work done at Carnegie Mellon demonstrated the potential for considerable capital and energy cost savings in the corn-to-ethanol process," explained Luca C. Zullo, technical director of Cargill Emissions Reduction Services. Zullo said the company decided to collaborate with Grossmann's team as a result of the explosive growth of the U.S. fuel ethanol industry.
He added, "We look forward to the time when the tools developed by Carnegie Mellon researchers will become part of the industry's new toolkit for making the process even more economical and sustainable."