METHOD FOR OBTAINING CELLULOSE FOR CHEMICAL PROCESSING FROM CELLULOSE-CONTAINING RAW MATERIALS Russian patent published in 2022 - IPC D21C1/04 D21C3/02 D21C5/00 

FIELD: pulp and paper industry.

SUBSTANCE: invention relates to cellulose production technology and can be used at pulp and paper industry enterprises in the manufacture of sulfate cellulose for chemical processing using additives that reduce the content of related ingredients in the target product, such as lignin, ash and resin components. The method includes a stage of prehydrolysis of cellulose-containing raw materials with sulfur-containing agents in the presence of an additive, sulfate cooking in a batch boiler and bleaching in several stages, one of which is an alkaline peroxide stage. The prehydrolysis step is carried out with an aqueous solution of acidic salts of sulfurous acid, and surfactants are used as an additive. After prehydrolysis, cellulose-containing raw materials are treated with alkaline peroxide filtrate from the 2^nd stage of alkalinization from the previous stage of bleaching in the presence of a wetting agent. A section of miscanthus is used as a cellulose-containing raw material. Potassium hydrosulfite or magnesium hydrosulfite or sodium hydrosulfite or ammonium hydrosulfite are used as acid salts of sulfurous acid in an amount of 0.3-0.5% by weight of an absolutely dry section of miscanthus. As a surfactant, alphanol 702 is used, which is an aqueous solution of ionic and nonionic components, or SAS 95, which is a mixture of secondary sodium alkyl sulfonates with an average chain length of C 15, in an amount of 0.02-0.09% of the weight of an absolutely dry miscanthus section. As a wetting agent, polyvinyl alcohol or polyethylene glycol or sodium polyacrylate is used in an amount of 0.02-0.04% of the weight of an absolutely dry miscanthus section. As an enzyme, xylonase is used in an amount of 0.01-0.02% of the weight of an absolutely dry section of miscanthus.

EFFECT: extension of the range of solutions in low waste technology.

5 cl, 1 tbl, 6 ex