Abstract: This invention relates to the electrofiltration of rendered animal fat. By means of this process, foreign bodies present in said fat are facilely removed without the conventional steps of water washing, centrifugation and drying. The use of electrofiltration instead of water washing, centrifugation and drying, besides avoiding the operation steps, also minimizes hydrolysis of fats to fatty acids. In addition, the physical loss of fat, which usually occurs during washing and subsequent steps, is minimized; and impurities not conventionally removed by water washing are removed, such as trace metals, etc. The electrofiltered product is a refined lard or tallow which is superior to lard or tallow prepared by conventional procedures.

Abstract: An improved process for the refining of crude oil selected from the group of fats, animal and vegetable oils. The crude oil is reacted with aqueous alkali to produce a treated oil with reduced acidic content but containing finely dispersed, liquid-state alkali metal soaps, and a bulk aqueous alkali phase. The bulk alkali phase is separated from the treated oil. The treated oil is subjected to electrofiltration by passage through a bed of dielectric particulate solids having open continuous, but tortuous flow paths, which are interposed within a d.c. electric field having a gradient of at least 20 kv/in whereby the alkali metal soaps adhere in a liquid state to the particulate solids and provide a purified oil with a substantially reduced content of the alkali metal soaps. The purified oil is sent to a subsequent utilization. A dielectric wash liquid is periodically flowed through the bed to remove the priorly adhering finely dispersed alkali metal soaps from the particulate solids.