Solvent dewaxing waxy hydrocarbon oils using dewaxing aid
AssigneeExxon Research & Engineering Co.
InventorBiddanda U. Achia
Life of this patent
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Abstract
An improved dewaxing aid for solvent dewaxing processes comprising a mixture of (a) lithium isostearate and (b) a polymer of an ester of at least one aliphatic alcohol with methacrylic acid or acrylic acid having an average molecular weight ranging from between about 300,000 to 2,000,000. The lithium isostearate, when combined with the acrylic polymer, synergistically improves the efficiency of wax separation. This has been found to be especially useful for dewaxing heavy petroleum oil fractions, such as bright stocks.
Claims12
A solvent dewaxing process comprising mixing a waxy hydrocarbon oil with dewaxing solvent and a dewaxing aid comprising a mixture of (a) lithium isostearate and (b) an acrylic ester polymer, which polymer has a number average molecular weight ranging from about 300,000 to 2,000,000 and which polymer is an ester of at least one aliphatic C.sub.6 -C.sub.30 alcohol, and chilling said oil, dewaxing solvent, and dewaxing aid mixture to form a slurry comprising solid particles of wax and a solution of dewaxed oil and dewaxing solvent and separating said wax from said dewaxed oil solution.
A solvent dewaxing process comprising chilling a mixture of a waxy petroleum oil fraction, a dewaxing solvent and a dewaxing aid used in an amount ranging from about 0.01 to 0.50 wt.% of said oil and comprising a mixture of (a) lithium isostearate and (b) an acrylic ester polymer having a number average molecular weight ranging from about 300,000 to 2,000,000, and which polymer is an ester of at least one aliphatic C.sub.6 -C.sub.30 alcohol, to form a slurry comprising solid particles of wax and a solution of dewaxed oil and solvent and separating said wax from said slurry.
A process for solvent dewaxing a bright stock comprising mixing said bright stock with a dewaxing aid in an amount ranging from 0.01 to 0.50 wt.% of said bright stock and with dewaxing solvent to form a mixture and chilling said mixture to form a slurry comprising solid particles of wax and a solution of dewaxed oil and solvent and separating said wax from said slurry and wherein said dewaxing aid comprises a mixture of (a) lithium isostearate and (b) an acrylic ester polymer having a number average molecular weight ranging from about 300,000 to 2,000,000 and which polymer is an ester of at least one aliphatic C.sub.6 -C.sub.30 alcohol.
Dependencies are inferred from the claim text.