PROCESS FOR PRODUCING POWDERED CELLULOSE OR MICROCRYSTALLINE CELLULOSE Russian patent published in 2023 - IPC D21C3/16 C08B15/00 

FIELD: chemical industry.

SUBSTANCE: chemical processing of technical cellulose fibers. The method for obtaining powdered or microcrystalline cellulose includes treatment of cellulose with a solution of nitric acid, hydrolysis at elevated temperature, dehydration of the acid mass of cellulose, washing with water and drying. At the first stage, the cellulose is treated with a solution of nitric acid, during which the mass of cellulose is mixed while simultaneously spraying it with a solution of nitric acid sprayed from nozzles in the volume of the mass. At the second stage of treatment with a solution of nitric acid, the resulting reaction mass is sent to a rotary apparatus. In this apparatus, cellulose fibers are impregnated. Then the resulting reaction mass is fed into the reactor, in which it is heated with live or dead steam to the temperature of the start of the exothermic reaction of acid hydrolysis 55-60°C, after which the heating is stopped and when the temperature in the reactor reaches 85-90°C is kept for 20-60 minutes. After that, the acid mass of cellulose is washed with water to a pH value of 5.2-7.0, dehydrated, dried and milled.

EFFECT: possibility of using different cellulose raw materials to obtain on the same equipment a product line - both powdered and microcrystalline cellulose, differing from each other in an individual set of consumer properties.

2 cl, 1 tbl, 8 ex