PROCESS FOR PRODUCING MICROCRYSTALLINE CELLULOSE Russian patent published in 2023 - IPC D21C1/04 C08B15/00 

FIELD: producing microcrystalline cellulose.

SUBSTANCE: method for producing microcrystalline cellulose includes the extraction of cellulose from wood, hydrolysis, bleaching, drying, grinding to a fine state. Moreover, the unbleached pulp is extracted from biodamaged wood with an acid liquor, including sodium hydroxide NaOH and sodium sulfide Na₂S at a temperature of 170 – 171°С, within 5 hours. This is followed by hydromechanical processing of the fibrous suspension at a concentration of 1%, which is carried out by the method of alternating instantaneous hard contacts of the front of the incident jet of the suspension with a fixed metal barrier that occurs at an operating pressure of 7 MPa, accompanied by hydraulic shocks, while the jet velocity has a minimum value of 97.2 m/s, at which a water hammer occurs at the moment of its contact with the barrier. The degree of grinding on the Schipper-Rigler scale is in the range from 15°SR up to 80°SR.

EFFECT: invention makes it possible to obtain microcrystalline cellulose from biodamaged wood, unbleached cellulose, and the use of hydromechanical processing in the method makes it possible to separate fiber bundles into smaller ones, while reducing the costs of further chemical processing.

1 cl, 1 ex