US4553983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for recovering organic vapors from air
Assignee: Membrane Technology and Research Inc
•
Filing: 1984-07-31
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Granted: 1985-11-19
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Expires: 2004-07-31
Abstract
Abstract A process for recovering and concentrating organic vapor from a feed stream of air having an organic vapor content of no more than 20,000 ppm by volume. A thin semipermeable membrane is provided which has a feed side and a permeate side, a selectivity for organic vapor over air of at least 50, as measured by the ratio of organic vapor permeability to nitrogen permeability, and a permeability of organic vapor of at least 3x10-7 cm3 (STP) cm/cm2 sec.cm Hg. The feed stream is passed across the feed side of the thin semipermeable membrane while providing a pressure on the permeate side which is lower than the feed side by creating a partial vacuum on the permeate side so that organic vapor passes preferentially through the membrane to form an organic vapor depleted air stream on the feed side and an organic vapor enriched stream on the permeate side. The organic vapor which has passed through the membrane is compressed and condensed to recover the vapor as a liquid.
Inventors
- 👤 Richard W. Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:53
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/24; B01D53/00; B01D53/22
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
170 words
A process for recovering and concentrating organic vapor from a feed stream of air having an organic vapor content of no more than 20,000 ppm by volume, comprising: providing a thin semipermeable membrane having a feed side and a permeate side, a selectivity for organic vapor over air of at least 50, as measured by the ratio of organic vapor permeability to nitrogen permeability, and a permeability of organic vapor of at least 3×10 -7 cm 3 (STP) cm/cm 2 sec·cm Hg, passing the feed stream across the feed side of the thin semipermeable membrane while providing a pressure on the permeate side which is lower than the feed side by creating a partial vacuum on the permeate side such that organic vapor passes preferentially through the membrane to form an organic vapor depleted air stream on the feed side and an organic vapor enriched stream on the permeate side, and compressing and condensing the organic vapor which has passed through the membrane to recover the vapor as a liquid.
Claim 2
Dependent Claim
170 words
A process for recovering and concentrating organic vapor from a feed stream of air having an organic vapor content of no more than 20,000 ppm by volume, comprising: providing a thin semipermeable membrane having a feed side and a permeate side, a selectivity for organic vapor over air of at least 50, as measured by the ratio of organic vapor permeability to nitrogen permeability, and a permeability of organic vapor of at least 3×10 -7 cm 3 (STP) cm/cm 2 sec·cm Hg, passing the feed stream across the feed side of the thin semipermeable membrane while providing a pressure on the permeate side which is lower than the feed side by creating a partial vacuum on the permeate side such that organic vapor passes preferentially through the membrane to form an organic vapor depleted air stream on the feed side and an organic vapor enriched stream on the permeate side, and compressing and condensing the organic vapor which has passed through the membrane to recover the vapor as a liquid.
Claim 3
Dependent Claim
31 words
Process according to claim 1, wherein the thin semipermeable membrane is a rubbery material under the conditions of organic vapor composition of the feed stream and temperature of the feed stream.
Claim 4
Dependent Claim
26 words
Process according to claim 2, wherein the semipermeable membrane has a glass transition temperature (Tg) at least 20° C. below the temperature of the feed stream.
Claim 5
Dependent Claim
12 words
Process according to claim 1, wherein the vapor-depleted air stream is recirculated.
Claim 6
Dependent Claim
17 words
Process according to claim 4, wherein the feed stream has a temperature of at least 50° C.
Claim 7
Dependent Claim
17 words
Process according to claim 4, wherein the feed stream has a temperature of at least 100° C.
Claim 8
Dependent Claim
20 words
Process according to claim 1, wherein the feed stream has a vapor content of from 0.1 to 1 volume %.
Claim 9
Dependent Claim
16 words
Process according to claim 1, wherein the selectivity of the membrane is between 100 and 10,000.
Claim 10
Dependent Claim
25 words
Process according to claim 1, wherein the permeability of the membrane to organic vapor is above 1×10 -6 cm 3 (STP) cm/cm 2 sec·cm Hg.
Claim 11
Dependent Claim
41 words
Process according to claim 1, wherein the thin semipermeable membrane is provided as part of a composite membrane comprising a microporous membrane support layer and the thin semipermeable membrane is in the form of a barrier coating layer on the support.
Claim 12
Dependent Claim
16 words
Process according to claim 9, wherein the support membrane comprises an organic solvent resistant ultrafiltration membrane.
Claim 13
Dependent Claim
35 words
Process according to claim 1, wherein the total pressure on the product side is from 0.2 to 2 cm Hg and the total pressure on the feed side is from 80 to 100 cm Hg.
Claim 14
Dependent Claim
18 words
Process according to claim 1, wherein the organic vapor is a naptha, chlorinated hydrocarbon, acetone, ethanol, or methanol.
Claim 15
Dependent Claim
13 words
Process according to claim 1, wherein the organic vapor is perchloroethylene or trichloroethane.
Claim 16
Dependent Claim
27 words
Process according to claim 1, wherein the concentration of vapor in the organic vapor enriched stream on the permeate side is from 10 to 95 volume percent.
Claim 17
Dependent Claim
27 words
Process according to claim 1, wherein the concentration of vapor in the organic vapor enriched stream on the permeate side is from 10 to 70 volume percent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-18 | 1989-05-20 | 1989-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-18 | 1993-05-20 | 1993-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-18 | 1997-05-20 | 1997-11-19 | $7700.00 | Window Closed / Lapsed |