Patent ID: 7625728

Claim:
A method of processing lignocellulose-containing material from xylan-containing biomass comprising pentoses and hexoses to produce ethanol and xylitol, comprising the steps of hydrolyzing lignocellulose-containing material from xylan-containing biomass comprising pentoses and hexoses to produce a hydrolyzed solution comprising free pentoses and hexoses; said lignocellulose-containing material comprising at least one lignocellulosic material selected from the group consisting of cellulose and hemicellulose, said pentoses comprising at least one pentose-containing material selected from the group consisting of xylose and arabinose; said hexoses comprising at least one hexose-containing material selected from the group consisting of glucose, galactose, rhamnose and mannose; said xylan-containing matter selected from the group consisting of wood, hardwood, softwood, plants, plant constituents, grains, particulates of grains, stems, fiber, shells, corn cobs, corn stems, corn fibers, nutshells, almond shells, coconut shells, bagasse, cotton seed bran, cotton seed skins, wood chips, sawdust, woodpulp, processed paper, spent sulphite liquor, spent liquor from hardwood pulping, spent liquor from paper processing, spent liquor from woodpulp processing and sulphite cooking liquor; fermenting said hydrolyzed solution with microbes to produce a fermented solution comprising fermented ethanol, fermented xylitol and spent microbes, said fermenting comprising converting a substantial amount of said hexose in said hydrolyzed solution to fermented ethanol and reducing a substantial amount of said xylose in said hydrolyzed solution to fermented xylitol and fermented ethanol; said microbes comprising at least one fermenting microorganism selected from the group consisting of naturally occurring bacteria, recombinant bacteria, naturally occurring yeast, recombinant yeast, and fungi; wherein said microbes are capable of converting xylose to ethanol and xylitol, and capable of converting hexoses to ethanol; and distilling said fermented solution to produce distilled ethanol and a bottom product comprising xylitol and spent microbes; and separating by fractionating said bottom product using a method selected from chromatographic separation and membrane filtration, so as to provide a xylitol enriched fraction, wherein said xylitol enriched fraction comprises a greater concentration of xylitol than does the bottom product, on a dry substance (solids) basis.