METHOD OF PRODUCING BETULIN Russian patent published in 2019 - IPC C07J53/00 C07J63/00 B01D11/04 

FIELD: chemistry.

SUBSTANCE: invention relates to organic chemistry. Method of obtaining betulin is carried out in a closed extraction technological complex, including grinding of bark, extraction with toluene in flow-type extractor (1) with continuous countercurrent movement of bark and solvent. When the pressure in the extractor reaches 120–130 kPa, the pressure is released to atmospheric pressure and the extraction of the extract into blow tank (2), in which the solvent evaporates. From the blown tank, the extract is continuously sent to evaporator cube (3), from which the supersaturated extract is sent to vacuum dryer (7), from which crystallized betulin is selected. Steam from the heating jacket of vacuum dryer (7), after the heat is given off, is sent to desorber (20) to desorb the residual solvent from the extracted birch bark, then sequentially sent to heating jacket of extractor (1), to first recuperative heat exchanger (18) for heating the recycled solvent and then to cube-evaporator (2). Vapors from vacuum dryer (7) are sent to first (6) mixing condenser to be absorbed by the solvent, the latter is taken as vapors from blow tank (2) and condensed in second recuperative heat exchanger (4), and then sent to second mixing condenser (5) for their final condensation, and from the second mixing condenser the condensate is sent to florentine unit (16) to separate the solvent from the water. Water from florentine unit is cooled in compressor refrigeration unit (13) and sent to second mixing condenser (5) for the final condensation of solvent vapors. Solvent from the florentine unit is drained into first mixing condenser (6), from where it is sent to buffer tank (17) and after successive heating in compressor refrigeration unit (13), and then in first (18) and second (4) recuperative heat exchangers it is returned into extractor (1).

EFFECT: invention provides obtaining of betulin with purity up to 99 % and a yield of 47 % by weight of dry bark using the technology of a continuous extraction process with minimum energy consumption.

1 cl, 1 dwg