METHODS FOR CONVERTING CELLULOSIC WASTE TO BIOPRODUCTS

摘要

The present invention provides processes for converting cellulosic waste, such as municipal solid waste, to bioproducts such as monosaccharides and fermentation products.

主权项

1. A process for producing a monosaccharide composition from solid waste, the process comprising:
(i) forming a solid waste slurry comprising solid waste and water, wherein the slurry comprises from about 2 to about 8 percent by weight total solids, and wherein the solid waste comprises cellulose and ash; (ii) pulping the solid waste slurry to form a pulped solid waste slurry comprising cellulosic fiber; (iii) (a) fractionating the pulped solid waste slurry through a filtration medium having opening of from about 0.2 cm to about 2 cm to form an oversize stream comprising coarse contaminants and an undersize stream comprising cellulosic fibers and light contaminants and (b) fractionating the undersize stream to form a light contaminant stream comprising ash and a cellulosic fiber stream, wherein the cellulosic fiber stream comprises no more than about 15 percent by ash on a dry basis, and wherein the ash content of the cellulosic fiber stream is less than the ash content of the solid waste on a dry basis; (iv) dewatering the cellulosic fiber stream to form a dewatered cellulosic fiber stream having a solids content of from about 25 wt. % to about 60 wt. % and a dewatered cellulosic fiber aqueous stream; (v) treating the dewatered cellulosic fiber stream by contact with steam at a treatment temperature of at least 150° C. and a treatment pressure of at least 350 kPa (about 50 psig) to form steam treated cellulosic fiber; and (vi) forming a slurry comprising the steam treated cellulosic fiber, water and at least one cellulase enzyme, and incubating the slurry to form a hydrolyzed cellulosic composition comprising soluble glucose.