METHOD OF PROCESSING LARCH WOOD WASTES (VERSIONS) Russian patent published in 2024 - IPC C08B37/00 

FIELD: various technological processes.

SUBSTANCE: group of inventions relates to processing of larch wood wastes to obtain dihydroquercetin and arabinogalactan. Siberian or Dahurian larch sawmilling wastes, crushed to sawdust, are extracted with water in continuous mixing mode for 30 minutes and at atmospheric pressure, with wood sawdust : extractant ratio equal to 1:5. Sawdust with size of not more than 3 mm is used, extraction of sawdust with water is carried out at temperature of 80 °C. Extract is subjected to microfiltration prior to ultrafiltration on “Blue tape” filters with pore size of 2–3 mcm for removal of mechanical particles. Extract filtrate separated after microfiltration is subjected to ultrafiltration in a tangential filtration unit in a nitrogen atmosphere and at pressure of 1 atm., and to increase rate of ultrafiltration and extraction of target products: arabinogalactan in an amount of more than 72.6% of the amount in the initial filtrate of the larch sawdust extract and dihydroquercetin – more than 92.7% of the amount in the initial filtrate of the larch sawdust extract, concentration of the extract by ultrafiltration is carried out in the presence of an additive of methyl alcohol 2.5% and at pH from 1.8 to 4.2. In the second version, the extract is concentrated by ultrafiltration in presence of 0.07% sodium chloride additive and at pH from 1.8 to 3.98.

EFFECT: simplified processing of wastes and increased rate of ultrafiltration.

2 cl, 3 dwg