Center for Environmental Research and Technology

Abstract

The research team has developed a highly effective biorefinery strategy to convert lignocellulosic feedstocks into bioethanol and value-added polymers and high value chemicals based on a breakthrough pretreatment process. This technology maximizes profitable use of fermentable sugars and lignin from highly recalcitrant woody residues by employing a novel pretreatment called Co-solvent Enhanced Lignocellulosic Fractionation (CELF) invented at the University of California Riverside (UCR). 

CELF pretreatment combines delignification and hemicellulose hydrolysis (and/or sugars dehydration) into a single step by employing renewable aqueous tetrahydrofuran (THF) and very dilute sulfuric acid in a simple monophasic mixture to deconstruct raw cellulosic feedstocks at moderate temperatures and short contact times (15-20 min). With CELF over 95% of the total fermentable sugars from raw corn stover can be recovered using less than 10% of the enzymes required following most other pretreatments. CELF is also able to extract about 90% of the lignin to be recovered as a pure reactive lignin product (CELF lignin) suitable for conversion to high-value chemicals. 

CELF is unique in its capacity to integrate multiple complex operations to achieve the high sugar yields and lignin production needed for biomass-based fuels and chemicals to be economically competitive. CELF pretreatment capabilities include: integrating CELF with simultaneous saccharification and fermentation (SSF) to produce ethanol at high yields and valorizing CELF lignin as polymers suitable for application in plastics and as high value chemicals. This research utilizes wood residues, such as wood chips, saw dust, tree thinnings, and juvenile wood that are rich in carbohydrates and lignin, and performs a technoeconomic study based on experimental data to assess commercial feasibility of the plant.