Process and apparatus for continuous acid hydrolysis and saccharification

• US 4,257,818 A
• Filed: 04/24/1979
• Issued: 03/24/1981
• Est. Priority Date: 04/01/1977
• Status: Expired due to Term

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Tournier, Herve, Armanet, Jean-Michel, Hamm, Thomas, Sachetto, Jean-Pierre, Regnault, Alain
• Primary Examiner(s): Marcus, Michael S.
• Application Number:
  US06/032,891
• Time in Patent Office: 700 Days
• Field of Search: 127/1, 127/5, 422/209, 422/210, 422/270, 422/273, 34/126, 34/135, 202/100
• US Class Current: 127/1
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32

Abstract

Continuous hydrolysis to produce sugars is effected by cyclically immersing a solid, divided lignocellulosic material in a bath of concentrated hydrochloric acid and draining the material between successive immersions so as to dissolve the produced sugars, until the sugar concentration of the acid in the bath has attained a desired value.

The solid material and the liquid acid are delivered to a tubular horizontal rotary reactor arranged to provide a bath of the acid, to produce a rotating movement for cyclical immersion of the solid material in the bath of acid and longitudinally displace the solid material undergoing hydrolysis together with the acid of the bath and to continuously discharge solid residue and acid containing dissolved sugars due to overflow by gravity at an outlet end of the reactor.

Claims

1. In a reactor for continuously hydrolyzing lignocellulosic materials by contact with highly concentrated hydrochloric acid in which the reactor includes a horizontal rotating drum having an internal tubular surface, an inlet end and an outlet end, means defining an impregnation zone adjacent to said inlet end for admitting and impregnating the materials with the acid and means defining a hydrolyzing zone for hydrolyzing said materials following the impregnation zone, means for rotating the drum, means for feeding lignocellulosic materials to the impregnation zone, spraying means in said impregnation zone for spraying acid into said impregnation zone and soak the materials and form a liquid acid bath in the bottom of the reactor, a plurality of longitudinally extending paddles that project radially inwardly from the drum'"'"'s internal surface in the hydrolyzing zone for moving the materials through the acid bath in the bottom of the reactor, raising it out of the bath and thereafter dropping it back into the bath as the reactor rotates, and a helical propelling baffle having a plurality of turns mounted around the internal surface of the reactor and defining a helical channel for displacing the liquid bath in the bottom of the reactor from the impregnation zone through the hydrolyzing zone to said outlet end, and means for discharging the final product from said drum at said outlet end, the improvement comprising mounting the paddles in the helical channel defined by the helical baffle in the hydrolyzing zone of the reactor in staggered configuration with respect to the path of rotation of the reactor, one end of each of said paddles being in contact with the baffle while the opposite end is spaced from the baffle, with adjacent paddles having their opposite ends in contact with the baffle, whereby the acid bath in the bottom of the reactor will swing back and forth between the paddles as the paddles move through the bath in response to rotation of the reactor, said paddles having a substantial length so that the materials and acid lifted out of the bath by the paddles will fall downwardly, first toward the outlet end and then toward the inlet end from paddle to paddle as the reactor rotates, said motion of the materials and acid resulting in a more intimate contact between them while effecting a scrubbing of the internal wall of the reactor drum.