May 7, 2009

Purdue to find game changing way to produce biofuels

The center will investigate methods to bypass the currently used processes involving biological fermentation, reducing the need for large and expensive biorefineries and expanding the range of biofuels beyond ethanol.

The Department of Energy also chose Purdue's project as one of 16 that will be funded by President Obama's American Recovery and Reinvestment Act.

The five-year project to develop direct conversion technologies of plant biomass to fuels will create at least 20 new jobs for students, postdoctoral researchers and professional staff in Indiana and another eight jobs at partner institutions, said Maureen McCann, the associate professor of biological sciences who leads the project.

"This center will not only build the knowledge base that will give us a new generation of technologies in energy research for future implementation, but also has the potential to impact work force opportunities," she said. "New jobs are created directly through the funds given to the center, but there also will be a ripple effect as those we train go on to academia or industry and conduct their own enterprises in energy research. If we are successful in this program of high-risk, high-reward research, then it will result in job creation on a much wider scale as these new technologies are implemented into the green economy."

The Purdue center, named the Center for Direct Catalytic Conversion of Biomass to Biofuels, or C3Bio, will investigate methods to directly convert plant lignocellulosic biomass, the bulk of the plant, to biofuels and other bio-based products currently derived from oil by the use of new chemical catalysts and thermal treatments. The team aims to produce fuels that closely resemble gasoline in terms of their molecular makeup and energy density, she said.

The center team, which includes experts from the fields of biology, chemistry and chemical engineering, will study the interactions between catalysts and plant cell walls to design improved chemical reactions for the biomass-to-biofuel pipeline.

Mahdi Abu-Omar, a professor of chemistry, will co-chair the center with McCann. The research team also includes Nick Carpita, Clint Chapple, Dan Szymanski and Nathan Mosier from the College of Agriculture; Rakesh Agrawal, Nick Delgass, Fabio Ribeiro and Kendall Thomson from the College of Engineering; and Hilkka Kenttämaa, Chris Staiger and Garth Simpson from the College of Science.

The center will collaborate with the University of Tennessee, the National Renewable Energy Laboratory and Argonne National Laboratory, which have facilities capable of examining the interaction of catalysts with biomass at the atomic level, McCann said.

"The science of chemical catalysis hasn't been much applied to turning biomass into biofuels," McCann said. "We thought there was a real gap in applying a science that is the foundation of the petrochemical industry but for which very little research exists on living plants, or as we like to call them, young coal."

Most of the reactions used in the petrochemical industry, starting from oil, rely on inorganic chemical catalysts, McCann said. For example, inorganic catalysts are used to generate ethylene and propylene, which are then used to create polymers, paints and other materials.

In current fermentation technology, biological catalysts are used to break down starch in corn kernels to glucose, and living organisms, such as bacteria or yeast, also use their own enzymes to produce ethanol from the glucose. Research is being carried out to use biological catalysts to break down plant biomass as a much more abundant source of glucose and other sugars for fermentation by the bacteria or yeast.

"Biological catalysts are fragile," Abu-Omar said. " Chemical catalysts have played a critical role in providing us fuels in the 20th Century from petroleum. In the 21st Century we will need robust and cheap chemical catalysts to provide us with renewable fuels directly from biomass."

The current biological catalysts used also have difficulty in dealing with lignin, a highly complex macromolecule within the plant cell wall. Lignin prevents access to the polysaccharides in the wall that are the source of the useful glucose and xylose, McCann said.

"The fermentation technologies are only 40 to 50 percent efficient in terms of the carbon atoms you started out with in the biomass ending up in fuel molecules," she said. "We think with different catalysts, the lignin could actually be used and converted to fuel molecules. If we can use the lignin, there is the potential to double the amount of fuel from each unit of biomass. Also that fuel could be more energy-dense, more similar to gasoline, than ethanol."

Bypassing the fermentation process also could help scale down biorefinery size, she said.

"If you could use chemical catalysts or a combination of catalysts with heat, you might be able to scale down the large and expensive refineries that you need to carry out the fermentations," McCann said. "It may even make mobile hydrocarbon refineries possible, where you could take the refinery to the field instead of having to transport heavy biomass to another location."

McCann said the interdisciplinary team that draws on a variety of Purdue's strengths was instrumental in getting the award and will drive the center's success.

"With a group that combines multiple areas of expertise, ideas that are at the boundaries of disciplines start to emerge," she said. "Purdue has deep expertise in plant cell wall biology,  developing new scientific instrumentation, the chemistry of catalysis, and in thermal process engineering and the design of catalysts. In addition, we are located in Indiana, which has the necessary agricultural landscape for the development of biofuels, and great connections already exist between farmers, agribusiness, the state of Indiana and Purdue researchers. 

Purdue's long history of research in biofuels and supporting areas add to its strength, McCann said. The center has plans to establish connections with various research hubs across campus and other national research centers.

"Purdue has researchers that have been working on different aspects of energy biosciences for decades, building the foundation for the future," she said. "This center will bring together the massive amount of talented work that the university has accrued and will apply it to the next step in achieving a viable alternative energy source to finite and foreign oil."

Writer: Elizabeth Gardner, (765) 494-2081, ekgardner@purdue.edu

Sources: Maureen McCann, (765) 496-1779, mmccann@purdue.edu

Mahdi Abu-Omar, (765) 494-5302, mabuomar@purdue.edu

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

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