Fermentation of glucose with recycle of non-fermented components

摘要

A feedstock slurry of starch and acid is continuously moved through a high intensity tubular starch hydrolyzer to produce a fluid hydrolyzate containing glucose. This glucose-containing fluid is then fermented to form a fermentation product containing ethanol which is then distilled to separate the ethanol from the residue of the distillation which contains non-fermented carbohydrate materials. At least part of the distillation residue is recycled as part of the feedstock slurry of starch and acid to the hydrolyzer, thus allowing a substantial portion of the previously unfermented feedstock to be hydrolyzed to a fermentable glucose-containing fluid.