METHOD FOR PRODUCING CELLULOSE FROM NON-TIMBER PLANT RAW MATERIAL Russian patent published in 2023 - IPC D21C5/00 D21C9/00 D21C1/02 

FIELD: obtaining macromolecular compounds.

SUBSTANCE: invention is intended for the production of cellulose used as a raw material in paper, chemical industry and as an additive for the production of various composite materials. The method is carried out by using stinging nettle, whereas stems are used to obtain cellulose, which does not prevent from obtaining a lot of biologically active substances (BAS) from nettle leaves, and the content of BAS in the stems is insignificant. To open the capillary-porous structure of cellulose in the method claimed, the stems are steamed with saturated steam at 100-105°C, for 20-30 minutes, which loosens the cellulose structure, softens the lignin, which allows bleaching under milder conditions. Delignification is carried out according to chlorine-free technology by alkaline 1.5-2.5% NaOH solution at a temperature of 75-86°С and processing time 40-50 min at a bath modulus of 1:10, followed by filtration and subsequent treatment with hydrogen peroxide in an alkaline medium at a hydrogen peroxide concentration of 2.5-3.5% and an alkali concentration of 1.5-2.5%, at a temperature of 60-70°C and treatment time 50-60 min at a bath modulus of 1:10, the resulting cellulose is filtered, treated with a 0.5% sulfuric acid solution to neutralize the cellulose and remove residual impurities at a bath modulus of 1:10, the resulting cellulose is filtered, washed with water until neutral reaction, dried to a moisture content of 5-7%.

EFFECT: production of cellulose with a mass fractionα of cellulose 90.1%, with a lignin content of 0.13%, with an ash content of 1.4%, with a resin and fat content of 0.1%, an average ЫЗ of 1050, with a yield of 54%.

1 cl, 5 tbl