Scientists study woody poplars as biomass for biofuel

http://www.ecoseed.org/technology-article-list/article/2-technology/9370-scientists-study-woody-poplars-as-biomass-for-biofuel

Wednesday, March 30, 2011

By Katrice R. Jalbuena Scientists from the Department of Energy’s BioEnergy Research Center are testing core samples from poplar trees. Scientists from the Department of Energy’s BioEnergy Science Center are studying plant structure in order to develop the next sources of biomass for biofuel. Focusing on poplar trees, Charles Wyman of the Bourns College of Engineering’s Center for Environmental Research and Technology at the University of California, Riverside led a research team to study the composition of lignin in plant cell walls. Mr. Wyman worked with colleagues in Oak Ridge National Laboratory and the National Renewable Energy Laboratory. Lignin, or learning how to break it down efficiently, is a roadblock in biofuel production. “The real driver for bioenergy is how to get sugar as cheaply as possible from these recalcitrant materials,” said Mr. Wyman. “We’re looking for clues as to which traits in these polar materials will lead to better sugar release.” Poplar trees, botanically known as populus, represent a leading woody crop candidate for biomass feedstocks. Using a high-throughput screening method, the researchers analyzed poplar core samples and found a correlation between a plant’s S/G ratio and increased sugar yields. The S/G ratio refers to the two main building blocks of lignin, syringyl and guaiacyl subunits. The researchers found that high S/G ratios do not negatively influence sugar yields. In fact the samples with the highest sugar yields belonged to the group with average S/G ratios. For his part, lead author Michael Studer said, “Conventional wisdom is that high lignin contents are bad for sugar release. We unexpectedly found that this statement is only valid for low S/G ratios, while at high S/G ratios lignin does not negatively influence yields.” “However, replacement of carbohydrates with lignin reduces the maximum possible sugar release, he added. Mr. Studer said samples with the highest sugar release belonged to the group with average S/G ratios and lignin contents, meaning a deeper understanding of the cell wall structure is needed before plants can be engineered for efficient biofuels production. The team’s study also pinpointed certain poplar samples that could produce high sugar yields with no pretreatment. Costly pretreatments, such as applying high temperatures, pressure and even chemicals to biomass materials jack up the price of biofuels and reducing pretreatment could make these alternative fuels more affordable. The researchers believe that understanding these traits could help determine which poplars are best suited for widespread cultivation as a biomass feedstock for biofuel production. From this work, superior poplar cultivars may soon be available for commercial testing and propagation, yielding plant materials that will contribute to reducing the nation’s dependence on fossil fuel based transportation fuels. The team, supported by B.E.S.C. at O.R.N.L., included co-lead Mark Davis and Robert Sykes from the National Renewable Energy Laboratory, Jaclyn DeMartini from U.C.R., and Brian Davison and Martin Keller from O.R.N.L. O.R.N.L. researchers, along with researchers at Virginia Tech and the University of Georgia previously worked with woody biomass to create a fuel cell that produced hydrogen gas using a mixture of enzymes, water, and wood chips. The process was said to have the highest hydrogen yield reported from cellulosic materials. Latest News-Cellulosic Biofuel Range Fuels raises $ 80 million to launch cellulosic biofuel plant Power sector helps drive jump in India carbon dioxide emissions New Tennessee plant banks on switchgrass for cellulosic ethanol Scientists create yeast to boost cellulosic biofuel production Interest in cellulosic ethanol goes global

Last update (Thursday, March 31, 2011)