METHOD FOR EXTRACTING WAX MIXTURE FROM USED FILTER POWDER Russian patent published in 2023 - IPC C11B11/00 C11B13/04 

FIELD: oil and fat industry.

SUBSTANCE: methods for degreasing used filter powder, which is a waste during the winterization of vegetable oils, used to obtain secondary raw materials. The method for degreasing used filter powder includes heating, partial degreasing of the used filter powder to obtain a wax mixture and a partially defatted filter powder, extracting the wax mixture from the partially defatted filter powder with alcohol to obtain a suspension, separating the suspension to obtain a miscella and a defatted filter powder, drying defatted filter powder with complete distillation of alcohol. At the same time, partial degreasing of the used filter powder heated to 90-110°C is carried out by centrifugation at normal atmospheric pressure and the centrifuge rotor speed from 15 s^-1 to 20 s^-1 for 30-60 minutes until a residual oil content of 18-25% is reached, the separation of the suspension is carried out mechanically at normal atmospheric pressure, the wax mixture extracted by centrifugation is mixed with the miscella obtained by separating the suspension, and the alcohol is distilled off, while isopropyl or ethyl alcohol is used as the alcohol. Moreover, for the mechanical separation of the suspension, vibrating separation or centrifugation can be used, and the residual oil content of the defatted filter powder is 0-0.2%.

EFFECT: complete degreasing of the filter powder, reduction of the peroxide value of the extracted wax mixture, and reduction of the number of required process operations.

4 cl, 1 dwg, 1 tbl, 4 ex