THERMOCHEMICAL TREATMENT OF LIGNOCELLULOSICS FOR THE PRODUCTION OF ETHANOL

摘要

A method to process lignocellulosic biomass into ethanol under conditions of high biomass loading is disclosed. Pretreatment of biomass was conducted at a high concentration of solids but with a relatively low concentration of ammonia relative to the dry weight of biomass. The pretreated biomass was washed to remove inhibitors and to minimize the carry-over of the inhibitors to the subsequent steps of saccharification and fermentation. The pretreated-washed biomass is ground at some point prior to saccharification. Enzymes are added to allow saccharification and biomass liquification. More solids are added in a fed- batch manner as saccharification proceeds to ultimately obtain fermentation of a high- biomass concentration and get a higher ethanol titer. The amount of solids added in the fed- batch is such that the process achieves optimum hydrolysis to sugars by the saccharification enzymes.