THIN (WIPED) FILM EVAPORATION FOLLOWED BY CLAY TREATMENT

The Wiped Film Evaporator is widely used world over for re-refining of used lubricating oil. This is supplied as a continuous or a semi continuous plant depending upon the capacity and the location of the plant. The minimum distance between the evaporating surface and the condenser coupled with short residence time makes this process one of the best in the market. The clay treatment process, regenerative clay process or solvent extraction can be used for the purpose of polishing and decolourizing the distilled product, which is obtained from evaporation process,into supreme grade base oil of different viscosities for different applications.

In this process, after distillation we use the clay treatment for the decolourisation. Clay treatment is often used as a finishing step for the distilled lube from vacuum distillation. The clay needs to be activated by heating so that it can effectively treat the oil. The clay can be regenerated through a controlled combustion cycle and can be used multiple times before being disposed of. The clay treatment removes color, odor and some sulfur. The finished product meets API Group I base oil specifications but does not remove the unsaturated compounds to meet API Group II specifications. Clay treatment may be better suited for smaller plant capacities due to lower capital investment.