Method for producing sweet juice from lignocellulosic biomass with improved enzyme recycle

摘要

The present invention relates to a method of producing sweet juice from lignocellulosic substrate, wherein enzymatic hydrolysis is carried out by performing cellulase supplementation with supported β-glucosidases used in a reactor separate from the lignocellulose enzymatic hydrolysis reactor.

主权项

1. A method of producing a lignocellulosic hydrolyzate (sweet juice) for alcoholic fermentation from a lignocellulosic substrate by enzymatic hydrolysis, comprising
(a) a lignocellulose conversion stage, comprising (1) contacting the lignocellulosic substrate with a cellulase solution in a first reactor to produce a first hydrolyzate, wherein said lignocellosic substrate has been pretreated to improve the susceptibility of the substrate to enzymatic hydrolysis; (2) sending the thus-produced first hydrolyzate obtained at the outlet of said first reactor to a separation means, whereby cellulases in the first hydrolyzate are extracted from the first hydrolyzate and retained by the separation means for return to the first reactor, to produce a cellulase-free first hydrolyzate; (3) sending the cellulase-free first hydrolyzate to a second reactor comprising immobilized β-glucosidases, wherein said second reactor is separate from said first lignocellulose enzymatic hydrolysis reactor, to produce a second hydrolyzate, and separating the second hydrolyzate from the immobilized β-glucosidases; (b) a sweet juice production stage, comprising
(1) adding the retained cellulases from the separation means in step (a)(2) to the second hydrolyzate;(2) contacting said second hydrolyzate including retained cellulases with new lignocellulosic substrate, whereby retained cellulases in the second hydrolyzate are adsorbed by the new substrate and a third hydrolyzate (first sweet juice) for alcoholic fermentation is produced, and(3) recycling the cellulases adsorbed to the new substrate to said first reactor; and (c) a reactor emptying stage, comprising completely emptying the first and second reactors.