METHOD FOR MAKING CELLULOSE FOR CHEMICAL PROCESSING Russian patent published in 2023 - IPC D21C3/06 

FIELD: pulp and paper industry.

SUBSTANCE: invention relates to a technology for production of cellulose for chemical processing, which can be used to produce cellulose nitrate esters. According to the method, sulphite pulping of birch wood is carried out in one stage with sulphite cooking acid, then fine fibres are separated from unbleached pulp in an amount of 7-8%, and then bleaching of unbleached pulp is carried out according to a scheme that includes delignification with hydrogen peroxide in an acidic medium in the presence of a sodium molybdate catalyst, alkaline treatment with the addition of sodium hypochlorite, acid treatment, hot alkaline refining. After hot refining, bleaching is carried out with sodium hypochlorite.

EFFECT: invention makes it possible to simplify the process of obtaining unbleached cellulose and to impart qualitative characteristics to bleached refined cellulose, allowing it to be used for the production of cellulose nitrate esters.

9 cl, 3 ex, 1 tbl