Two-StageFractionation and Fiber Production of Lignocellulosic Biomass forLiquid Fuels and Chemicals.

Inthe current study, a simple two-step fractionation process was developedfor utilization of hardwood biomass without forming troublesome stickylignin condensation products. The four product streams generated area hemicellulose extract, a lignin extract, separated wood fibers (pulp)and wood fiber bundles (rejects). All four product streams can befurther utilized for production of transportation fuel, chemicals,and biomaterials. The optimum fractionation conditions for mixed southernhardwood chips are the following: extraction with 10 g/L formic acid(FA) at 160 °C for 90 min followed by extraction with 50% (w/w)EtOH at 80 °C for 90 min. The yield of pulp and reject fibersthat are produced from the FA and EtOH pre-extracted wood chips bymechanical action are 38% and 28%, respectively. Cellulose to glucoseconversion yield of the FA treated wood, as well as that of the finalpulp and fiber bundles by enzymes, are strongly improved comparedto that of the original hardwood chips. [ABSTRACT FROM AUTHOR]