Progress Made in Reducing Cost of Producing Ethanol

Ethanol has been criticized for not being the most cost-efficient form of energy. But new research shows promise for converting biomass to ethanol more economically.

Genencor scientists and colleagues from the Department of Energy's National Renewable Energy Laboratory (NREL) acknowledged the significance of the completion of their 4-year collaboration to reduce the costs of enzymes to enable a commercially viable process of using cellulosic biomass. The company reports it has been successful in reducing enzyme costs enough to produce an affordable version of bioethanol made from corn stalks, wheat and other materials.

The cost of the cellulase enzyme it has produced is 10 cents to 20 cents per gallon below the cost model developed by the National Renewable Energy Laboratory. This represents an approximate 30-fold improvement in enzyme cost in that model. NREL is expected to validate these results at pilot scale within the next quarter. Genencor notes that the actual enzyme cost and the final cost of ethanol in a commercial process will be heavily dependent upon overcoming the remaining hurdles in the development of integrated biorefineries.

"We have exceeded the contractual goals and the expectations of the DOE and NREL," says Michael V. Arbige, Genencor's senior vice president of technology. "But more importantly, we have overcome a critical hurdle in making biorefineries and alternative fuels a reality."

The technology developed is an important step toward realizing the potential of biorefineries, analogous to an oil refinery today, in which plant and waste materials are used to produce an array of fuels and chemicals. Further progress toward a commercially viable biorefinery depends on the development of pilot-scale, real-world processes for biomass conversion. Genencor is working with Cargill-Dow on such a project, also funded by the Department of Energy (DOE), and looks forward to working with others as biorefinery development advances toward industrial scale.