US5288307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method to reduce fuel vapor emissions
Assignee: Dow Chemical Co
•
Filing: 1992-08-28
•
Granted: 1994-02-22
•
Expires: 2012-08-28
Abstract
Abstract Hydrocarbon emissions from fuel reservoirs, particularly those associated with motor vehicles, are abated by contacting a vented hydrocarbon fuel vapor stream from the reservoirs with a polymeric adsorbent derived from a macroporous or macroreticular copolymer of at least one monovinylidene aromatic monomer and a crosslinking monomer. The macroporous copolymers are converted into suitable adsorbents by post-polymerization crosslinking in a swollen state in the presence of a Friedel-Crafts catalyst. The resulting adsorbent has improved hydrocarbon adsorption capacity relative to conventional activated carbon adsorbents.
Inventors
- 👤 H. Robert Goltz
- 👤 Tom N. Demopolis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:41
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/22; B01J20/26; C; C08; C08F; C08F8/00; C08F8/18; C08F8/24; F; F02; F02M; F02M25/00; F02M25/08; F02M25/0854; Y; Y10; Y10S; Y10S95/00; Y10S95/90
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
77 words
A method for reducing hydrocarbon fuel vapor emissions from fuel reservoirs which comprises: contacting a vented hydrocarbon fuel vapor stream from a fuel reservoir with a polymeric adsorbent to retain at least a portion of the hydrocarbon fuel vapors emitted from reservoir, the polymeric adsorbent comprising a macroporous or macroreticular copolymer of at least one monovinylidene aromatic monomer and a crosslinking monomer which has been post-crosslinked in a swollen state in the presence of a Friedel-Crafts catalyst.
Claim 2
Independent Claim
77 words
A method for reducing hydrocarbon fuel vapor emissions from fuel reservoirs which comprises: contacting a vented hydrocarbon fuel vapor stream from a fuel reservoir with a polymeric adsorbent to retain at least a portion of the hydrocarbon fuel vapors emitted from reservoir, the polymeric adsorbent comprising a macroporous or macroreticular copolymer of at least one monovinylidene aromatic monomer and a crosslinking monomer which has been post-crosslinked in a swollen state in the presence of a Friedel-Crafts catalyst.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein the at least one monovinylidene aromatic monomer is selected from styrene, vinylbenzyl chloride, vinyltoluene, ethylstyrene, or t-butylstyrene.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein the crosslinking monomer is selected from divinylbenzene, trivinylbenzene, or ethylene glycol dimethacrylate.
Claim 5
Dependent Claim
45 words
The method of claim 1 wherein the macroporous or macroreticular copolymer comprises from about 99.25 to about 95 weight percent of the at least one monovinylidene aromatic monomer and from about 0.75 to about 5 weight percent of the crosslinking monomer, based on monomer weight.
Claim 6
Dependent Claim
28 words
The method of claim 1 wherein the macroporous or macroreticular copolymer further comprises less than about 30 weight percent of a non-aromatic monovinylidene monomer based on monomer weight.
Claim 7
Dependent Claim
19 words
The method of claim 5 wherein the nonaromatic monovinylidene monomer is methyl methacrylate, methyl acrylate, or methyl ethyl acrylate.
Claim 8
Dependent Claim
99 words
The method of claim 1 wherein the macroporous or macroreticular copolymer is post-crosslinked by steps which comprise: contacting the macroporous or macroreticular copolymer with a haloalkylating agent under conditions sufficient to substitute the copolymer with haloalkyl moieties; removing any excess haloalkylating agent from the copolymer; swelling the copolymer with a swelling agent; maintaining the swollen copolymer at a temperature and in the presence of a Friedel-Crafts catalyst such that individual haloalkyl moieties on a copolymer chain react with an aromatic ring of an adjacent copolymer chain to form a bridging moiety; and removing the swelling agent from the copolymer.
Claim 9
Dependent Claim
12 words
The method of claim 7 wherein the haloalkyl moieties are chloromethyl groups.
Claim 10
Dependent Claim
15 words
The method of claim 7 wherein the bridging moiety is a --CH 2 -- moiety.
Claim 11
Dependent Claim
11 words
The method of claim 7 wherein the swelling solvent is dichloroethane.
Claim 12
Dependent Claim
21 words
The method of claim 1 wherein the polymeric adsorbent has a total porosity of from about 0.5 to about 1.5 cc/g.
Claim 13
Dependent Claim
30 words
The method of claim 11 wherein from about 0.04 to about 0.5 cc/g of the total porosity is composed of macropores having a diameter of at least about 100 Å.
Claim 14
Dependent Claim
22 words
The method of claim 1 wherein the polymeric adsorbent has a specific surface area of at least about 1200 m 2 /g.
Claim 15
Dependent Claim
21 words
The method of claim 1 wherein the polymeric adsorbent has a butane working capacity of at least about 14 g/100 cc.
Claim 16
Independent Claim
122 words
A method for reducing hydrocarbon fuel vapor emissions from fuel reservoirs which comprises: contacting a vented hydrocarbon fuel vapor stream from a fuel reservoir with a polymeric adsorbent to retain at least a portion of the hydrocarbon fuel vapors emitted from the fuel reservoir, the adsorbent comprising a macroporous or macroreticular copolymer of at least one monovinylidene aromatic monomer and a crosslinking monomer which is post-crosslinked in a swollen state in the presence of a Friedel-Crafts catalyst, the macroporous or macroreticular copolymer comprising a cellular polymeric structure wherein a macroporous void phase is dispersed within a continuous copolymer phase, the void phase comprising a plurality of cellular void spaces which are at least partially enclosed by walls of the continuous copolymer phase.
Claim 17
Independent Claim
122 words
A method for reducing hydrocarbon fuel vapor emissions from fuel reservoirs which comprises: contacting a vented hydrocarbon fuel vapor stream from a fuel reservoir with a polymeric adsorbent to retain at least a portion of the hydrocarbon fuel vapors emitted from the fuel reservoir, the adsorbent comprising a macroporous or macroreticular copolymer of at least one monovinylidene aromatic monomer and a crosslinking monomer which is post-crosslinked in a swollen state in the presence of a Friedel-Crafts catalyst, the macroporous or macroreticular copolymer comprising a cellular polymeric structure wherein a macroporous void phase is dispersed within a continuous copolymer phase, the void phase comprising a plurality of cellular void spaces which are at least partially enclosed by walls of the continuous copolymer phase.
Claim 18
Dependent Claim
26 words
The method of claim 15 wherein the macroporous or macroreticular copolymer comprises from about 1 to about 4 weight percent crosslinking monomer based on monomer weight.
Claim 19
Dependent Claim
20 words
The method of claim 15 wherein the cellular void spaces have diameters of from about 100 to about 2000 Å.
Claim 20
Dependent Claim
23 words
The method of claim 15 wherein the at least one monovinylidene aromatic monomer is selected from styrene, vinylbenzyl chloride, vinyltoluene, ethylstyrene, or t-butylstyrene.
Claim 21
Dependent Claim
18 words
The method of claim 15 wherein the crosslinking monomer is selected from divinylbenzene, trivinylbenzene, or ethylene glycol dimethacrylate.
Claim 22
Dependent Claim
21 words
The method of claim 15 wherein the at least one monovinylidene aromatic monomer is styrene and the crosslinking monomer is divinylbenzene.
Claim 23
Dependent Claim
29 words
The method of claim 15 wherein the macroporous or macroreticular copolymer further comprises less than about 30 weight percent of a non-aromatic monovinylidene monomer based on total monomer weight.
Claim 24
Dependent Claim
21 words
The method of claim 21 wherein the nonaromatic monovinylidene monomer is selected from methyl methacrylate, methyl acrylate, or methyl ethyl acrylate.
Claim 25
Dependent Claim
100 words
The method of claim 15 wherein the macroporous or macroreticular copolymer is post-crosslinked by steps which comprise: contacting the macroporous or macroreticular copolymer with a haloalkylating agent under conditions sufficient to substitute the copolymer with haloalkyl moieties; removing any excess haloalkylating agent from the copolymer; swelling the copolymer with a swelling agent; maintaining the swollen copolymer at a temperature and in the presence of a Friedel-Crafts catalyst such that individual haloalkyl moieties on a copolymer chain react with an aromatic ring of an adjacent copolymer chain to form a bridging moiety; and thereafter removing the swelling agent from the copolymer.
Claim 26
Dependent Claim
12 words
The method of claim 23 wherein the haloalkyl moieties are chloromethyl groups.
Claim 27
Dependent Claim
15 words
The method of claim 23 wherein the bridging moiety is a --CH 2 -- moiety.
Claim 28
Dependent Claim
11 words
The method of claim 23 wherein the swelling solvent is dichloroethane.
Claim 29
Dependent Claim
21 words
The method of claim 15 wherein the polymeric adsorbent has a total porosity of from about 0.5 to about 1.5 cc/g.
Claim 30
Dependent Claim
30 words
The method of claim 27 wherein from about 0.04 to about 0.5 cc/g of the total porosity is composed of macropores having a diameter of at least about 100 Å.
Claim 31
Dependent Claim
22 words
The method of claim 15 wherein the polymeric adsorbent has a specific surface area of at least about 1200 m 2 /g.
Claim 32
Dependent Claim
21 words
The method of claim 15 wherein the polymeric adsorbent has a butane working capacity of at least about 14 g/100 cc.
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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) | 1997-02-21 | 1997-08-23 | 1998-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-21 | 2001-08-23 | 2002-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-21 | 2005-08-23 | 2006-02-22 | $7700.00 | Window Closed / Lapsed |