METHOD OF PRODUCTION OF MICROCRYSTALLINE CELLULOSE Russian patent published in 2002 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to methods of production of powder microcrystalline cellulose. Cellulose hydrolysis is carried out at hydromodulus = (1:10)-(1:15) at temperature 85 C with 5-% solution of mineral acid for 85 min followed by squeezing out and withdrawal of the spent destructing solution, washing out, drying, dispersing and screening. The spent destructing solution is used in repeated hydrolysis carrying out. Acid flows obtained after cellulose washing out and an acid fresh solution to brought about its concentration to the parent value of destructing solution are added to the spent destructing solution and used its in hydrolysis of the next portion of fibrous cellulose. Washing out powder cellulose is carried out by the method squeezing out-dilution-squeezing out for two steps using countercurrent use of acid flows: on the first step washing out is carried out with acid flows formed after the second washing out step; on the second step washing out is carried out with fresh water. The spent destructing solution and acid flows are used ten-fold in the process of hydrolysis and washing out being without deterioration of quality indices of cellulose. Method ensures to decrease the consumption of concentrated acid, fresh water and amount of acid flows and without deterioration of the end product quality. EFFECT: improved method of production. 4 tbl, 40 ex