초록
<P>Developing economically viable cellulosic ethanol process requires concentrated fermentable sugars and minimum water consumption. Biorefinery economics requires highly integrated efficiencies in the full utilization of all biomass components. Toward this objective, we have developed an enzyme-free mechanocatalytic saccharification process that combines mix-milling of P<SUB>2</SUB>O<SUB>5</SUB> with lignocelluloses and successive hydrolysis into fermentable sugars. Demonstrated with corn stover (CS) and CS-xylose residues, after recovery of valuable hemicellulose, fermentable glucose in 75% yield at a high biomass loading (92 mg/mL) was obtained with concomitant precipitation of pristine lignin. The undetoxified concentrated hydrolysate allows for fermentative upgrading, achieving 42 g/L ethanol (a benchmark (40g/L) for an economically feasible bioethanol process) in 52 h after hemicellulose is converted into xylose. P<SUB>2</SUB>O<SUB>5</SUB> is essential in fragmentation of cellulose in the milling stage and subsequent accelerated hydrolysis to glucose by in situ produced H<SUB>3</SUB>PO<SUB>4</SUB>. The mechanocatalytic saccharification of biomass involving P<SUB>2</SUB>O<SUB>5</SUB> is compatible with xylose and lignin recovery and facilitates the integrated conversion of all three biomass fractions.</P><P>Mechanocatalytic saccharification of biomass involving P<SUB>2</SUB>O<SUB>5</SUB> is compatible with xylose and lignin recovery and facilitates the integrated conversion of all three biomass fractions.</P><BR>[FIG OMISSION]</BR>