METHOD FOR PRODUCING CELLULOSE FROM MISCANTHUS FOR CHEMICAL PROCESSING Russian patent published in 2022 - IPC D21C1/04 D21C3/02 D21C5/00 

FIELD: production of cellulose.

SUBSTANCE: invention relates to a method for producing cellulose and can be used at enterprises of the cellulose and paper industry in production of cellulose for chemical processing using additives contributing to reduction of the content of associated ingredients, such as lignin, ash and resin components, in the target product. The method includes the stage of prehydrolysis of the miscanthus cutting with sulphur-containing reagents in the presence of an additive. Two-stage delignification of the miscanthus cutting with an alkaline solution in a batch boiler and bleaching in several stages, wherein one of the stages comprises a first and a second alkaline peroxide bleaching stages. The stage of prehydrolysis is executed by an aqueous solution of acidic salts of sulphurous acid, and surface active agents (surfactants) are used as an additive. After prehydrolysis, the cellulose-containing raw materials are treated with a peroxide alkaline filtrate from the second stage of alkali extraction from the previous stage of bleaching in the presence of a wetting agent. Potassium hydrosulphite, or sodium hydrosulphite, or ammonium hydrosulphite in an amount of 0.5 to 0.9% of the weight of the absolutely dry miscanthus cutting are used as acid salts of sulphurous acid. OP-7 or OP-10 - surface active agents constituting products of processing a mixture of mono- and dialkylphenols with ethylene oxide are used as a surfactant in an amount of 0.025 to 0.08% of the weight of the absolutely dry miscanthus. Polyvinyl alcohol, polyethylene glycol and sodium polyacrylate are used as a wetting agent in an amount of 0.02 to 0.04% of the weight of the absolutely dry miscanthus cutting.

EFFECT: production of cellulose for chemical processing.

4 cl, 1 tbl, 6 ex