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U.S. Department of Energy
Office of Scientific and Technical Information

Dilution chilling dewaxing by modification of tower temperature profile

Patent ·
OSTI ID:6207507
An improved DILCHILL dewaxing process is described wherein waxy lubricating oil stocks are solvent dewaxed by contacting them with successive increments of cold dewaxing solvent at a plurality of points along the height of a vertical tower divided into a plurality of stages while agitating the oilsolvent mixture in each stage to provide substantially instantaneous mixing of the waxy oil and solvent thereby precipitating wax from the oil while avoiding the well known shock chilling effect. The improvement resides in adjusting the cold solvent addition to each stage in a manner so as to modify the temperature profile along the tower to ensure that the temperature drop per stage in the initial stages in which wax precipitation occurs is greater than the temperature drop per stage in the final or later stages in which wax precipitation occurs.
Assignee:
Exxon Research and Engineering Co.
Patent Number(s):
US 4146461
OSTI ID:
6207507
Country of Publication:
United States
Language:
English