METHOD OF DEGREASING OF SPENT FILTER POWDER RESULTED FROM VEGETABLE OIL REFINING Russian patent published in 2016 - IPC C11B13/04 

FIELD: fat and oil production.

SUBSTANCE: invention relates to fat and oil production industry. Method of degreasing of waste filtration powder used for refining vegetable oils using organic solvent, namely trichloroethylene, is carried out in two stages. At the first stage the spent filter powder is mixed during 0.25-0.5 h at temperature of 75-80 °C with miscella separated at the second stage of filter powder degreasing with trichloroethylene, taken to the weight of filter powder in ratio 1:6-1:8, simultaneously exposed to ultrasound specific power equal to 8-12 WT/cm² with frequency 40-50 kHz. Then obtained suspension is filtered by plate vertical filter. Filtered miscella supplied to distillation at residual pressure of 50-100 kPa/cm² and temperature of 65-70 °C for distillation of trichloroethylene and separation of oil. Filter powder deposited on the plate-type filter is dried by compressed air under pressure 2.5-3.5 kg/cm² for 0.2 h and then is subject to second stage of degreasing. At first it is washed with 6-8-fold amount of trichloroethylene acc. weight of powder at temperature 75-80 °C. Then washed residue is blown by compressed air at pressure 2.5-3.5 kg/cm² for 0.2 hours. Then the defatted filter powder is discharged from plates of the filter into evaporator and trichloroethylene is distilled at residual pressure of 50-100 kPa/cm² and temperature of 65-70 °C. Trichloroethylene distilled at the first and second stages of degreasing can be reused. Miscella separated at the second stage of defatting is used at the first stage of defatting for mixing with new portion of waste filtration powder.

EFFECT: invention allows to eliminate pyrophoricity and transfer waste filter powder to V hazard class due to complete defatting, improve the environmental factors and enhance the quality of extracted oil by prevention of chlorine release and its reaction with unsaturated oil components during solvent distillation.

1 cl, 6 tbl, 3 ex