Patent EP0013834A2 successfully refreshed from Google Patents.
EP0013834A2
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EP
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Method of converting a hydrophilic, water-containing regenerated cellulose membrane to a membrane useful for separating organic liquids
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1979-12-28
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Granted: —
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Expires: 1999-12-28
Abstract
Abstract A hydrophilic, water-containing regenerated cellulose membrane is sequentially permeated under differential pressure with solvents of decreasing polarity so as initially to displace water in the membrane with a first solvent, and the or each other solvent in the sequence displacing the previous solvent. Each solvent has bulk liquid-liquid miscibility with the adjacent soivent(s) in the sequence, and the final solvents of the sequence exhibits bulk liquid-liquid miscibility with a material ultimately desired to be selectively permeated through the membrane. The first solvent is a lower (C,-C 4 ) alcohol or acetone. The resulting membrane is particularly suitable for at least partially separating, by permeation, a solvent used in dewaxing a waxy hydrocarbon oil from a solution of the oil and solvent.
Inventors
- 👤 John Arthur Thompson
- 👤 David Henry Shaw
- 👤 David Arvydas Gudelis
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 10:13
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088; B01D61/00; B01D61/02; B01D61/025; B01D71/00; B01D71/06; B01D71/08; B01D71/10; C; C10; C10G; C10G73/00; C10G73/02; C10G73/025
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
150 words
A method of converting a hydrophilic, water-containing regenerated cellulose membrane to a membrane useful for separating organic liquids which converting process is characterized by sequentially permeating the water-containing membrane with one or more solvents of decreasing polarity in turn, under pressure, to first displace the water in the membrane with a first solvent followed by sequentially displacing each preceding solvent in the membrane with the next, successive solvent of lower polarity, the said first solvent being a low molecular weight alcohol or ketone which exhibits bulk, liquid-liquid miscibility with both the water in the said water-containing regenerated cellulose membrane and the next, lower polarity solvent immediately following said first solvent, and wherein any two solvents which are adjacent in the sequential series exhibit bulk liquid-liquid miscibility with each other, and wherein the final solvent exhibits bulk liquid-liquid miscibility with the material ultimately desired to be selectively permeated through the membrane.
Claim 2
Independent Claim
150 words
A method of converting a hydrophilic, water-containing regenerated cellulose membrane to a membrane useful for separating organic liquids which converting process is characterized by sequentially permeating the water-containing membrane with one or more solvents of decreasing polarity in turn, under pressure, to first displace the water in the membrane with a first solvent followed by sequentially displacing each preceding solvent in the membrane with the next, successive solvent of lower polarity, the said first solvent being a low molecular weight alcohol or ketone which exhibits bulk, liquid-liquid miscibility with both the water in the said water-containing regenerated cellulose membrane and the next, lower polarity solvent immediately following said first solvent, and wherein any two solvents which are adjacent in the sequential series exhibit bulk liquid-liquid miscibility with each other, and wherein the final solvent exhibits bulk liquid-liquid miscibility with the material ultimately desired to be selectively permeated through the membrane.
Claim 3
Dependent Claim
30 words
The method of claim 1 characterized in that the pressure differential across the membrane is in the range of from 100 to 800 psi (7.031 to 56.248 kg/cm 2 ).
Claim 4
Dependent Claim
27 words
The method of claim 1 or claim 2 characterized in that said first solvent is selected from the C l -C 4 alcohols, acetone and mixtures thereof.
Claim 5
Independent Claim
24 words
The method of any one of claims 1 to 3 characterized in that said membrane is less than about 10 mils (0.254 mms) thick.
Claim 6
Independent Claim
36 words
The method of any one of claims 1 to 4 characterized in that the final solvent has a size and shape similar to the ultimate material that is desired to be selectively permeated through said membrane.
Claim 7
Dependent Claim
30 words
A membrane which is selectively permeable to an organic liquid characterized in that it has been made by a method in accordance with any one of claims 1 to 5.
Claim 8
Dependent Claim
60 words
A process for at least partially separating at least one selected organic liquid from a feed comprising a mixture thereof characterized by contacting the feed with one side of at least one semi-permeable membrane according to claim 6, with a differential pressure across the membrane and which membrane is selectively permeable with respect to the said one selected organic liquid.
Claim 9
Dependent Claim
150 words
A process according to claim 7 characterized in that the semi-permeable membrane (Fig. 3;32) is selectively permeable to a dewaxing solvent of a mixture comprising dewaxed oil and dewaxing solvent, and in that the feed (Fig. 3; line 30) is at least a portion of a dewaxed oil/dewaxing solvent mixture obtained from a solvent dewaxing operation wherein a waxy hydrocarbon, petroleum or lube oil stock is solvent-dewaxed (Fig 3; 20) with a dewaxing solvent to form a slurry (Fig. 3; line 24)) comprising solid particles of wax and a mixture of dewaxed oil and dewaxing solvent, and wherein the solid particles of wax are separated (Fig 3; 26) from the slurry to leave the said dewaxed oil/dewaxing solvent mixture, and forming a permeate (Fig. 3; line 34) richer in said dewaxing solvent than the mixture and a retentate (Fig 3; line 36) leaner in said dewaxing solvent than the mixture.
Claim 10
Dependent Claim
165 words
A process according to claim 7 characterized in that the semi-permeable membrane (Fig. 4; 22) is selectively permeable to a dewaxing solvent of a solution of foots oil and dewaxing solvent, and in that the feed (Fig. 4; line 20) is at least a portion of a solution of foots oil and solvent obtained from a slack wax-deoiling operation wherein a mixture of foots oil containing slack wax and solvent is warmed or heated (Fig. 4; 30) to dissolve at least a portion of the foots oil to form a slurry (Fig. 4; line 13) comprising solid particles of wax and a solution of foots oil and solvent, and wherein the solid particles of wax are separated (Fig. 4; 14) from the slurry to leave the said foots oil and solvent solution (Fig. 4; line 20), and forming a permeate (Fig. 4; line 24) richer in said solvent than said solution and a retentate (Fig. 4; line 26) leaner in said solvent than said solution.
Claim 11
Dependent Claim
40 words
A process according to claim 8 or claim 9 characterized by recovering the solvent-enriched permeate (Fig. 3; line 34) and recycling at least a portion thereof for use as at least part of the dewaxing solvent (Fig. 3; line 12).
References Cited (Backward Citations)
No citation records indexed.
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