Exxon Research and Engineering Company

Ralph R Hall

David H Shaw

Stephen F Perry

An improved process for the solvent dewaxing of petroleum oil stocks. Wax-containing oil is chilled in an elongated chilling zone by introducing cold dewaxing solvent into said zone, at a plurality of points along same, said chilling zone containing or having associated with it a plurality of static means for mixing the solvent and wax-containing oil under conditions of plug flow radial mixing, thereby avoiding shock chilling without the need for the intense agitation and/or dynamic agitators normally required for such processes.

Dewaxing waxy oil by dilution chilling employing static mixing means

An improved dilution chilling dewaxing process for waxy petroleum oils wherein the dewaxed oil yield is increased and the solvent recovery requirements are decreased by recycling solvent-rich wash filtrate from the first stage wax filters back into the dilution chilling dewaxing zone.

Dilchill dewaxing using wash filtrate solvent dilution

Ketone dewaxing solvent is separated and recovered from dewaxed oil and a wax slurry through the use of flash vaporization or distillation followed by steam stripping. Water is removed from the recovered solvent through the use of a combination of a decanting drum to form a solvent phase and a water phase, a deketonizer tower which strips solvent from the water phase, and a simple distillation tower which functions as a solvent dehydrator. It has been found that feeding a portion of the overhead vapors from the flash vaporization step directly to the bottom of the dehydrator provides enough heat to eliminate the need for a reboiler on the dehydrator tower.

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Morristown, NJ, United States of America

Ralph R Hall