METHOD OF PRODUCING HEMICELLULOSE EXTRACTS Russian patent published in 2020 - IPC C08L5/14 B01D11/04 

FIELD: technological processes.

SUBSTANCE: present invention discloses a method of purifying a hemicellulose extract obtained, for example, by extraction with hot water. Said extracts often contain a large amount of colloidal material which mainly consists of lignin and other phenol compounds. Colloidal particles clog the equipment, such as ultrafiltration membranes, as a result, use of such equipment is virtually impossible. Raw material is in contact with an aqueous medium at temperature of up to 250 °C to obtain a hemicellulose extract in the form of an aqueous stream containing dissolved hemicelluloses and dispersed colloidal substances. Further, the temperature of the water stream is controlled within range of 10 to 120 °C. Water stream is brought into contact with material capable of adsorbing dispersed colloidal substances to produce aqueous hemicelluloses solution, residual haze of which, measured at room temperature, is less than 200 NTU. Aqueous stream containing dissolved hemicelluloses is subjected to a step where the concentration of hemicelluloses is increased by filtration.

EFFECT: technical result is effective removal of turbidity-inducing particles, which reduces probability of filter clogging, high content of hemicellulose in solution.

20 cl, 5 dwg