摘要 |
<p>The present invention relates to a process for producing alcohol from a cellulosic material, said process comprising: hydrolyzing said cellulosic material with an aqueous acid to produce a hydrolysate; extracting acid and water from said hydrolysate with a water-miscible organic extraction solvent to yield (a) a first aqueous acidic solution containing said extraction solvent and (b) a residue containing sugars; subjecting said residue to an oligosaccharide cleavage reaction to yield an aqueous solution of fermentable sugars; fermenting said fermentable sugars and distilling alcohol from the resulting fermented mixture; contacting said first aqueous acidic solution with a water-immiscible liquid lipophilic solvent to yield a second aqueous acid solution and a solvent mixture of said extraction solvent and said liquid solvent; separating said solvent mixture to yield extraction solvent for recycling; and separating from said second aqueous acid solution an aqueous acid for recycling.</p> |