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US 4,368,112 AGranted
Solvent recovery from foots oil using modified regenerated cellulose membranes
AssigneeExxon Research & Engineering Co.
InventorsJohn A. Thompson, David H. Shaw, David A. Gudelis
Life of this patent
Estimating the term…
Abstract
A warm-up deoiling process for lube oil slack wax wherein cold slack wax from a solvent dewaxing operation is warmed up and mixed with solvent to dissolve foots oil contained therein and passed to a rotary drum filter to recover solid wax and a filtrate comprising a solution of foots oil and solvent wherein said filtrate is contacted with one side of a semi-permeable membrane made from regenerated cellulose which selectivity permeates at least a portion of solvent through said membrane and recycling the permeated solvent directly back into the warm-up deoiling operation as part of the solvent mixed with the slack wax.
Claims25
A process comprising:
- (a) warming up a mixture of foots oil containing slack wax and solvent to dissolve at least a portion of the foots oil to form a slurry comprising solid particles of wax and a solution of foots oil and solvent;
- (b) passing said warm slurry to solid-liquid separation means to separate the solid particles of wax from the foots oil solution;
- and
- (c) contacting at least a portion of said foots oil solution, under pressure, with one side of at least one semi-permeable membrane made from regenerated cellulose film to form a permeate richer in said solvent than said mixture and a retentate leaner in said solvent than said solvent than said mixture, wherein said semipermeable membrane is prepared from a water-containing hydrophilic regenerated cellulose membrane by sequentially permeating through said water-containing membrane, under a differential pressure across the membrane, a series of solvents of decreasing polarity wherein adjacent solvents in the series exhibit bulk liquid-liquid miscibility with each other and wherein the last solvent exhibits bulk liquid-liquid miscibility with the dewaxing solvent to be permeated through the membrane.
1 more element
A process comprising:
- (a) warming up a mixture of foots oil containing slack wax and solvent to dissolve at least a portion of the foots oil to form a slurry comprising solid particles of wax and a solution of foots oil and solvent;
- (b) passing said warm slurry to solid-liquid separation means to separate the solid particles of wax from the foots oil solution;
- and
- (c) contacting at least a portion of said foots oil solution with one side of at least one semi-permeable membrane made from regenerated cellulose film at a differential pressure across said membrane ranging from about 100 to 800 psi wherein said membrane preferentially permeates at least a portion of said solvent through said membrane to form a permeate richer in said solvent and a retentate leaner in said solvent than said foots oil solution, wherein said semi-permeable membrane is prepared from a water containing hydrophilic membrane by sequentially permeating through said water-containing membrane, under a differential pressure across the membrane, a series of solvents of decreasing polarity wherein adjacent solvents in the series exhibit bulk liquid-liquid miscibility with each other and wherein the last solvent exhibits bulk liquid-liquid miscibility with the solvent to be permeated through the membrane.
1 more element
A process comprising:
- (a) mixing a foots oil containing slack wax with a solvent;
- (b) warming said mixture to dissolve at least a portion of the foots oil in said solvent to form a slurry comprising solid particles of wax and a solution of foots oil;
- and
- (c) passing said warm slurry to a wax filter to separate said solid wax from said foots oil solution;
- (d) contacting said foots oil solution with one side of a plurality of semi-permeable membranes made from regenerated cellulose film at a differential pressure across said membranes ranging from about 100 to 800 psi, said membranes preferentially permeating at least a portion of said solvent therethrough to form a permeate richer in said solvent and an oil-rich retentate leaner in said solvent than said solution, wherein each of said semi-permeable membranes is prepared from a water-containing hydrophilic membrane by sequentially permeating through a water-containing membrane, under a differential pressure across the membrane, a series of solvents of decreasing polarity wherein adjacent solvents in the series exhibit buld liquid-liquid miscibility with each other and wherein the last solvent exhibits bulk liquid-liquid miscibility with the solvent to be permeated through the membrane;
- and
- (e) recycling at least a portion of said permeate back to step (a) wherein it is mixed with said slack wax.
4 more elements
Dependencies are inferred from the claim text.