MICROFILTRATION OF USED OIL

摘要

An apparatus and method for recycling used oil is disclosed. The apparatus includes a feedstock of used oil entering a feed line, a circulation pump for pumping a flow of used oil at a pressure of at least 105 psi, a heat exchanger for heating the flow of used oil to a temperature of 200 DEG C to 500 DEG C, at least one microfiltration unit containing a plurality of microfiltration membranes with pore sizes ranging from 0.1 to 0.5 microns for microfiltering the flow of used oil and separating therefrom a permeate of recycled oil and retaining a retentate of used oil for recirculation in the system. During operation, the flow of used oil upstream of the microfiltration unit is controlled by monitoring temperature or pressure in the system to remain at a Reynolds number of at least 2,300.