Abstract: Methods and apparatus to separate a light lube stock product and a heavy lube stock product from heavy dewaxed lube oils are described which maintain product specifications while utilizing conventional refinery equipment. The heavy dewaxed lube oil stream is first heated, such as in a spiral heat exchanger in the top of a vacuum stripper, with the heavy lube stock fraction, and/or with hot oil. Next, the heated heavy dewaxed lube oil stream is injected into the vacuum stripper, and fuel gas is injected at the bottom of the stripper as the stripping medium. A light lube stock fraction is removed from the upper portion of the stripper, and a heavy lube stock fraction is removed from the lower portion thereof. Optionally, the gas stripping medium is removed from the top of the stripper by a vacuum pump and used to fuel a hot oil exchanger to heat the oil which in turn is employed to heat the heavy dewaxed lube oil stream.

Abstract: Dewaxed lube base stock oil which forms a wax haze on storage at a temperature above its cloud point is treated by contacting the oil and hydrogen with a zeolite catalyst such as ZSM-5 to eliminate the wax-haze formation. The method may be used to reclaim wax-contaminated lube base stock oils and other wax-contaminated hydrocarbon oils.