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US 5,102,551 AGranted
Membrane process for treating a mixture containing dewaxed oil and dewaxing solvent
AssigneeTexaco Inc.
InventorMordechai Pasternak
Life of this patent
Estimating the term…
Abstract
Charge containing dewaxed oil and dewaxing solvent (typically methyl ethyl ketone and toluene) is treated to separate dewaxing solvent by use of a separating elastomer membrane barrier of a polysiloxane which has been cross-linked as with toluene diisocyanate, adipoyl dichloride, a dialkoxy silane, or a diacetoxy silane.
Claims14
The process for treating a charge containing dewaxing solvent and dewaxed oil which comprises
- passing said charge containing dewaxing solvent and dewaxed oil into contact with, as separating membrane, a non-porous elastomer separating polysiloxane membrane layer which has been cross-linked with, as cross-linking agent, (i) a polyisocyanate or (ii) a poly(carbonyl chloride) or (iii) a silane R.sub.4-a Si (A).sub.a wherein A is --OH, --NH.sub.2, --OR, or --OOCR, a is 2, 3, or 4, and R is hydrogen or an alkyl, aralkyl, cycloalkyl, aryl, or alkaryl group;
- maintaining a pressure drop across said membrane thereby forming a high pressure retentate containing increased content of dewaxed oil and decreased content of dewaxing solvent and a low pressure permeate containing increased content of dewaxing solvent and decreased content of dewaxed oil;
- maintaining the pressure on the low pressure discharge side of said membrane above the vapor pressure of said permeate thereby maintaining said permeate in liquid phase;
- maintaining the pressure on the high pressure retentate side of said membrane above the vapor pressure of said charge containing dewaxing solvent and dewaxed oil and sufficient to drive permeate across said membrane thereby maintaining said charge dewaxing solvent and dewaxed oil and said retentate in liquid phase;
- recovering said permeate containing increased content of dewaxing solvent and decreased content of dewaxed oil;
- and
- recovering said retentate containing increased content of dewaxed oil and decreased content of dewaxing solvent.
4 more elements
The process for treating a charge containing dewaxing solvent and dewaxed oil which comprises
- passing said charge containing dewaxing solvent and dewaxed oil into contact with, as separating membrane, a non-porous elastomer separating polysiloxane layer which has been cross-linked with a toluene diisocyanate cross-linking agent;
- maintaining a pressure drop across said membrane thereby forming a high pressure retentate containing increased content of dewaxed oil and decreased content of dewaxing solvent and a low pressure permeate containing increased content of dewaxing solvent and decreased content of dewaxed oil;
- maintaining the pressure on the low pressure discharge side of said membrane above the vapor pressure of said permeate thereby maintaining said permeate in liquid phase;
- maintaining the pressure on the high pressure retentate side of said membrane above the vapor pressure of said charge containing dewaxing solvent and dewaxed oil and sufficient to drive permeate across said membrane by thereby maintaining said charge dewaxing solvent and dewaxed oil and said retentate in liquid phase;
- recovering said permeate containing increased content of dewaxing solvent and decreased content of dewaxed oil;
- and
- recovering said retentate containing increased content of dewaxed oil and decreased content of dewaxing solvent.
4 more elements
Dependencies are inferred from the claim text.