Patent EP0146298A2 successfully refreshed from Google Patents.
EP0146298A2
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Method and apparatus for separating filter aid from separated wax by selective permeation through a membrane
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1984-12-03
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Granted: —
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Expires: 2004-12-03
Abstract
Abstract Dewaxing aids used to facilitate the separation of waxes from waxy hydrocarbon oils in solvent dewaxing processes are recovered from the solvent free separated wax (1) by means of an ultrafiltration process employing a selective membrane (in 2A, 2B, 2C, 2D and 5A, 5B, 5C) selected from polysulfone, nylon and cellulose acetate, preferably polysulfone, under specific conditions of temperature, pressure and flow velocity. The selective membrane is preferably used in the form of a spiral wound element which employs a feed/retentate spacer made of a specific polyester material to enhance mixing and reduce pressure drop in the element.
Inventors
- 👤 John Arthur Thompson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 02:41
CPC Classifications
B; B01; B01D; B01D63/00; B01D63/10; B01D71/00; B01D71/06; B01D71/66; B01D71/68; C; C10; C10G; C10G73/00; C10G73/02; C10G73/04; B01D2311/00; B01D2311/10; B01D2311/103; B01D2311/14; B01D2311/16; B01D2313/00; B01D2313/14; B01D2313/143
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
109 words
A method for separating dewaxing aid from wax comprising contacting a selectively permeable membrane in spiral wound element form with a hot mixture of wax and dewaxing aid at a temperature of between about 70 to 150°C and at a feed flow velocity through the element of about 1 to 4 cm/sec, and thereby selectively permeating said wax through the spiral wound membrane element yielding a permeate rich in wax and a retentate rich in dewaxing aid, the membrane being selected from polysulfone, nylon and cellulose acetate and spiral wound membrane element employing feed spacers and retentate spacers made of polyester or small diameter inert rods in its construction.
Claim 2
Independent Claim
109 words
A method for separating dewaxing aid from wax comprising contacting a selectively permeable membrane in spiral wound element form with a hot mixture of wax and dewaxing aid at a temperature of between about 70 to 150°C and at a feed flow velocity through the element of about 1 to 4 cm/sec, and thereby selectively permeating said wax through the spiral wound membrane element yielding a permeate rich in wax and a retentate rich in dewaxing aid, the membrane being selected from polysulfone, nylon and cellulose acetate and spiral wound membrane element employing feed spacers and retentate spacers made of polyester or small diameter inert rods in its construction.
Claim 3
Dependent Claim
11 words
The method according to claim 1 wherein the membrane is polysulfone.
Claim 4
Dependent Claim
23 words
The method according to claim 1 or claim 2 wherein the polyester feed and retentate spacer material is PE-25, PE-15 or Nylon 20.
Claim 5
Dependent Claim
64 words
The method according to claim 3 wherein the polyester feed spacer material and the retentate spacer material are each PE-25 having 23.9 strands per inch (9.4094 strands/cm) in its weave, wherein each strand has a diameter of 350 microns (350 x 10- 4 cm), and wherein the material has a fabric thickness of 780 microns (780 x 10- 4 cm) with 44.75% open area.
Claim 6
Independent Claim
28 words
The method of any one of claims 1 to 4 wherein the polysulfone polymer making up the membrane has a glass transition temperature of about 140°C and higher.
Claim 7
Dependent Claim
23 words
The method of claim 5 wherein the polysulfone polymer making up the membrane has a glass transition temperature of about 190°C and higher.
Claim 8
Independent Claim
54 words
The method of any one of claims 1 to 6 wherein the polysulfone membrane is about 3 to 15 mils (1.18 x 10- 4 to 5.906 x 10 -4 cm) thick and has an average pore diameter of about 500 to 2,000 R (500 x 10 -10 m to 2000 x 10- 10 m).
Claim 9
Independent Claim
37 words
The method of any one of claims 1 to 7 wherein the hot dewaxing aid and wax mixture is contacted with the membrane in the spiral wound membrane element at a temperature of about 70 to 100°C.
Claim 10
Independent Claim
39 words
The method of any one of claims 1 to 8 wherein the hot dewaxing aid and wax mixture is contacted with the spiral wound membrane element at a gauge pressure of about 50 psig (344.75 kPa) or slightly lower.
Claim 11
Independent Claim
37 words
The method of any one of claims 1 to 9 wherein the hot dewaxing aid and wax mixture is passed over the membrane in the spiral wound membrane element at a flow rate of about 2 cm/sec.
Claim 12
Dependent Claim
102 words
A spiral wound element made using a central mandril-permeate tube around which is wrapped layers of membrane, feed spacers and permeate spacers, wherein layers of membrane surround the permeate spacers and are secured around 3 edges to define an envelope which is communicatively attached to the central mandril-permeate tube and a feed spacer is employed between envelope layers, wherein the feed spacer material is positioned at the forward feed inlet edge of the element and is only wide enough to resist movement or displacement along the element down the feed channel under the pressure and flow velocity employed in using the element.
Claim 13
Dependent Claim
102 words
A spiral wound element made using a central mandril-permeate tube around which is wrapped layers of membrane, feed spacers and permeate spacers, wherein layers of membrane surround the permeate spacers and are secured around 3 edges to define an envelope which is communicatively attached to the central mandril-permeate tube and a feed spacer is employed between envelope layers, wherein the feed spacer material is positioned at the forward feed inlet edge of the element and is only wide enough to resist movement or displacement along the element down the feed channel under the pressure and flow velocity employed in using the element.
Claim 14
Dependent Claim
37 words
The element of claim 11 wherein the feed spacer which is is positioned at the forward feed inlet edge of the element is of a width of from about 2 to 10% of the overall element length.
References Cited (Backward Citations)
No citation records indexed.
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