CELLULOSE HYDROLYSIS WITH pH ADJUSTMENT Russian patent published in 2017 - IPC C07H3/02 C07H1/08 C08B1/00 C12P19/02 C12P19/04 B01J3/06 

FIELD: pulp and paper industry.

SUBSTANCE: present invention relates to a method of processing lignocellulose and can be used in chemical industry. Disclosed method involves preparation of lignocellulose biomass, which comprises a first solid fraction, containing cellulose and lignin, a first liquid fraction; separation of said first solid fraction from said first liquid fraction; mixing said first solid fraction with water to form a suspension; wherein said suspension has pH from 3.0 to 4.5; raising said pH of said suspension by 0.5 pH units to 5.0 pH units, to obtain a suspension with adjusted pH; wherein said suspension with adjusted pH has pH from 5.0 to 8.0; optionally, preliminary heating of said suspension with adjusted pH to temperature lower than critical point of water; bringing said suspension with adjusted pH into contact with a fluid for a second reaction, containing supercritical or close to supercritical fluid, to obtain a reaction mixture which contains a second solid fraction containing lignin; and a second liquid fraction containing soluble C₆-saccharide, selected from a group consisting of cellulo-oligosaccharides, glucose, galactose, mannose, fructose and mixtures thereof; wherein said supercritical or close to critical fluid contains water and, optionally, CO₂ at temperature equal to 300 °C or higher, and pressure, at least sufficiently high to ensure that all fluid for second reaction is in liquid phase or supercritical phase; and where said bringing said suspension with adjusted pH into contact with said fluid for second reaction has duration of more than 2 seconds; optionally, reducing temperature of said reaction mixture to temperature lower than 280 °C; and optionally, hydrolysis of said second liquid fraction to form C₆-saccharide, selected from a group consisting of C₆-oligosaccharide, having links with lower degree of polymerisation, glucose, galactose, mannose, fructose and mixtures thereof.

EFFECT: proposed method enables to efficiently prepare lignocellulose biomass, control degree of hydrolysis of cellulose and reduce level of decomposition of glucose.

31 cl, 3 ex, 7 dwg, 2 tbl