Production of Renewable Transportation Fuels
Today, carbon-rich fossil fuels, primarily oil, coal and natural gas, provide 85% of the energy consumed in the United States. The high energy content of liquid hydrocarbon fuels makes them the preferred energy source for cars, buses, trains and planes. The release of greenhouse gases from petroleum has spurred research into alternative, non-fossil energy sources. Among the options, only biomass has the potential to provide a high- energy-content liquid transportation fuel. Biomass is renewable resource that is nearly carbon-neutral. However, plant-derived biomass, in contrast to starch-based crops, contains cellulose that is difficult to convert to fermentable sugars.

From 1978 to 1986, Professor Blanch directed a DOE-supported research program on the conversion of lignocellulosic biomass to ethanol for blending in gasoline (gasohol). In a series of publications, he developed and optimized biomass pretreatment approaches, fermentations for the conversion of glucose and xylose sugars to ethanol, and energy efficient routes to recover ethanol and butanol. This work provided much of the background from which two major research initiatives were developed at UC Berkeley and the Lawrence Berkeley National Laboratory in 2006-7; the BP- supported Energy Biosciences Institute (EBI), and the DOE-supported Joint BioEnergy Institute (JBEI).

JBEI is one of three US Department of Energy Bioenergy Research Centers. As Chief Science and Technology Officer for JBEI, Professor Blanch lead 170 established scientists, post doctoral fellows, graduate and undergraduate students from JBEI’s participating organizations, in developing approaches to solve the key scientific problems in biofuels production and commercialization.

JBEI’s biomass-to-biofuels production approach is based in three interrelated scientific divisions and a technologies division. The Feedstocks Division creates the knowledge required for improving plant energy crops to serve as the raw materials for biofuels. The Deconstruction Division investigates the conversion of this lignocellulosic plant material to usable forms of sugar and aromatics. The Fuels Synthesis Division evolves microbes that can efficiently convert sugar and aromatics into ethanol and other biofuels. JBEI’s cross-cutting Technologies Division develops and optimizes a set of enabling technologies—including high-throughput, chip-based and ‘omics platforms, tools for synthetic biology, multi-scale imaging facilities, and integrated data analysis.

At the EBI, Professor Blanch’s research involved the development of ionic liquid solvent systems for pretreatment of biomass, with subsequent enzymatic hydrolysis of cellulose and hemicellulose to their monomer sugars. Directed evolution of cellulases from archaeal and thermophilic organisms was used to improve hydrolytic rates, and the kinetics of cellulase action on pretreated biomass has been modeled in detail. Solvent inhibition on microbial growth typically limits productivity and a number of approaches to understand and address it are being developed. The ABE fermentation has been employed to provide acetone and butanol for chemical conversion to higher carbon-number diesel fuels.

© Harvey Blanch 2013