US4523981A
Expired / Lapsed
US
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Means and method for reducing carbon dioxide to provide a product
Assignee: Texaco Inc
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Filing: 1984-03-27
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Granted: 1985-06-18
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Expires: 2004-03-27
Abstract
Abstract A process for reducing carbon dioxide to at least one useful product includes two redox couple electrolyte solutions separated by a first membrane having photosensitizers. The carbon dioxide to be reduced is separated from one of the redox couple electrolyte solutions by another membrane having a catalyst. Water provides hydrogen ions which participate in the reduction of carbon dioxide via a separator. In the operation both membranes are illuminated and produce excited solar sensitizers which cause electron transfer from a first redox solution to the second redox solution and then to the carbon dioxide to react with the hydrogen ions, reducing the carbon dioxide to provide at least one product.
Inventors
- 👤 Peter G. P. Ang
- 👤 Anthony F. Sammells
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:13
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/50; C25B1/55; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/36
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
172 words
A process for reducing carbon dioxide to at least one useful product comprising the steps of: a. providing a R II /O II redox coupled electrolyte solution, b. providing a R I /O I redox coupled electrolyte solution, c. separating the R II /O II solution from the R I /O I solution with a first membrane having photosensitizers, d. providing carbon dioxide, e. separating the carbon dioxide from the R I /O I solution with a second membrane having photosensitizers and a catalyst, f. providing water, g. separating the water from the carbon dioxide in a manner so that hydrogen ions, but not oxygen, may pass from the water to participate in the reduction of the carbon dioxide, and h. illuminating both membranes so as to produce excited photosensitizers to cause electron transfer from the R II /O II solution to the R I /O I solution thence to the carbon dioxide to cooperate with passed hydrogen ions in the reducing of the carbon dioxide to provide at least one product.
Claim 2
Dependent Claim
172 words
A process for reducing carbon dioxide to at least one useful product comprising the steps of: a. providing a R II /O II redox coupled electrolyte solution, b. providing a R I /O I redox coupled electrolyte solution, c. separating the R II /O II solution from the R I /O I solution with a first membrane having photosensitizers, d. providing carbon dioxide, e. separating the carbon dioxide from the R I /O I solution with a second membrane having photosensitizers and a catalyst, f. providing water, g. separating the water from the carbon dioxide in a manner so that hydrogen ions, but not oxygen, may pass from the water to participate in the reduction of the carbon dioxide, and h. illuminating both membranes so as to produce excited photosensitizers to cause electron transfer from the R II /O II solution to the R I /O I solution thence to the carbon dioxide to cooperate with passed hydrogen ions in the reducing of the carbon dioxide to provide at least one product.
Claim 3
Dependent Claim
46 words
A process as described in claim 1 in which the R II /O II redox coupled electrolyte solution is selected from the group of redox couples consisting of H 2 O/O 2 , Br - /Br 2 , methylene blue, Fe +2 /Fe +3 and EDTA.
Claim 4
Dependent Claim
38 words
A process as described in claim 2 in which the first membrane's photosensitizer is selected from the group of photosensitizers consisting of n-TiO 2 , n-Fe 2 O 3 , n-WSe 2 , p-InP, methylene blue and porphyrins.
Claim 5
Dependent Claim
43 words
A process as described in claim 3 in which the R I /O I redox coupled electrolyte solution is selected from the group of redox couples consisting of I - /I 2 , S 2- /S n 2- , triethanolamine and methyl viologen.
Claim 6
Dependent Claim
38 words
A process as described in claim 4 in which the second membrane's photosensitizer is selected from the group of photosensitizers consisting of p-InP, p-WSe 2 , p-GaAs, p-CdTe, n-WSe 2 , n-CdSe, Ru(bipy) 3 Cl 2 and phthalocyanines.
Claim 7
Dependent Claim
66 words
A process as described in claim 5 in which the catalyst is on the surface of the second membrane that is in contact with the CO 2 and is selected from the group of catalysts consisting of dichalcogenides of the metals (Ni, Co, Mo, W), SrTiO 3 , NADPH, metal coatings (Pb, In), amalgams (Ni, Zn), chrysene, ethyl acrylate, phthalocyanines (Ni, Co), porphyrins and methyl viologen.
Claim 8
Dependent Claim
51 words
A process as described in claim 6 in which the R II /O II couple is Br - /Br 2 , the first membrane's photosensitizer is n-WSe 2 , the R I /O I couple is I - /I 2 and the photosensitizer in the second membrane is n-WSe 2 .
Claim 9
Dependent Claim
47 words
A process as described in claim 6 in which the R II /O II couple is H 2 /H 2 O, the first membrane's photosensitizer is p-InP, the R I /O I couple is S 2- /S n 2- , and the second membrane's photosensitizer is n-CdSe.
Claim 10
Dependent Claim
44 words
A process as described in claim 6 in which the R II /O II couple is methylene blue, the first membrane's photosensitizer is p-InP, the R I /O I couple is S 2- /S n 2- , and the second membrane's photosensitizer is n-CdSe.
Claim 11
Dependent Claim
47 words
A process as described in claim 6 in which the R II /O II couple is Fe +2 /Fe +3 , the first membrane's photosensitizer is methylene blue, the R I /O I couple is triethanolamine, and the second membrane's photosensitizer is Ru(bipy) 3 Cl 2 .
Claim 12
Dependent Claim
39 words
A process as described in claim 6 in which the R II /O II couple is EDTA, the first membrane's photosensitizer is porphyrins, the R I /O I couple is methyl viologen, and the second membrane's photosensitizer is phthalocyanines.
Claim 13
Dependent Claim
19 words
A process as described in claim 6 in which the illuminating step includes exposing both membranes to solar radiation.
Claim 14
Dependent Claim
154 words
A process for reducing carbon dioxide to at least one useful product comprising the steps of: a. providing a R II /O II redox coupled electrolyte solution, b. providing carbon dioxide, c. separating the carbon dioxide from the R II /O II solution with first and second membranes having photosensitizers and the second membrane is in contact with the carbon dioxide and has a catalyst, and d. electrically connecting the first membrane to the second membrane, e. providing water, f. separating the water from the carbon dioxide in a manner so that hydrogen ions, but not oxygen, may pass from the water to participate in the reduction of the carbon dioxide, and g. illuminating both membranes so as to produce excited photosensitizers to cause electron transfer from the R II /O II solution to the carbon dioxide to cooperate with passed hydrogen ions in reducing the carbon dioxide to provide at least one product.
Claim 15
Dependent Claim
154 words
A process for reducing carbon dioxide to at least one useful product comprising the steps of: a. providing a R II /O II redox coupled electrolyte solution, b. providing carbon dioxide, c. separating the carbon dioxide from the R II /O II solution with first and second membranes having photosensitizers and the second membrane is in contact with the carbon dioxide and has a catalyst, and d. electrically connecting the first membrane to the second membrane, e. providing water, f. separating the water from the carbon dioxide in a manner so that hydrogen ions, but not oxygen, may pass from the water to participate in the reduction of the carbon dioxide, and g. illuminating both membranes so as to produce excited photosensitizers to cause electron transfer from the R II /O II solution to the carbon dioxide to cooperate with passed hydrogen ions in reducing the carbon dioxide to provide at least one product.
Claim 16
Dependent Claim
38 words
A process as described in claim 13 in which the R II /O II couple is H 2 O/O 2 , the first membrane's photosensitizer is n-TiO 2 , and the photosensitizer in the second membrane is p-InP.
Claim 17
Dependent Claim
38 words
A process as described in claim 13 in which the R II /O II couple is H 2 O/O 2 , the first membrane's photosensitizer is n-TiO 2 , and the second membrane's photosensitizer is p-WSe 2 .
Claim 18
Dependent Claim
38 words
A process as described in claim 13 in which the R II /O II couple is H 2 O/O 2 , the first membrane's photosensitizer is n-Fe 2 O 3 , and the second membrane's photosensitizer is p-GaAs.
Claim 19
Dependent Claim
38 words
A process as described in claim 13 in which the R II /O II couple is H 2 O/O 2 , the first membrane's photosensitizer is n-Fe 2 O 3 , and the second membrane's sensitizer is p-CdTe.
Claim 20
Dependent Claim
25 words
A process as described in claim 13 in which a biasing voltage is provided across the R II /O II electrolyte solution and the water.
Claim 21
Dependent Claim
16 words
A process as described in claim 18 in which the predominant product produced is formic acid.
Claim 22
Dependent Claim
14 words
A process as described in claim 18 in which the predominant product is formaldehyde.
Claim 23
Dependent Claim
14 words
A process as described in claim 18 in which the predominant product is methanol.
Claim 24
Dependent Claim
14 words
A process as described in claim 18 in which the predominant product is methane.
Claim 25
Dependent Claim
19 words
A process as described in claim 13 in which the illuminating step includes exposing the membrane to solar radiation.
Claim 26
Dependent Claim
106 words
Apparatus for reducing carbon dioxide to provide at least one product comprises: means for containing a first redox coupled electrolyte solution, means for containing a second redox coupled electrolyte solution, first means responsive to illumination for transferring electrons from the first electrolyte solution to the second electrolyte solution, means for containing water, means for containing carbon dioxide, means for providing hydrogen ions from the water to the carbon dioxide, and second means responsive to illumination for transferring electrons from the second electrolyte to the carbon dioxide where the transferred electrons and the hydrogen ions cooperate to reduce the carbon dioxide thereby providing at least one product.
Claim 27
Dependent Claim
106 words
Apparatus for reducing carbon dioxide to provide at least one product comprises: means for containing a first redox coupled electrolyte solution, means for containing a second redox coupled electrolyte solution, first means responsive to illumination for transferring electrons from the first electrolyte solution to the second electrolyte solution, means for containing water, means for containing carbon dioxide, means for providing hydrogen ions from the water to the carbon dioxide, and second means responsive to illumination for transferring electrons from the second electrolyte to the carbon dioxide where the transferred electrons and the hydrogen ions cooperate to reduce the carbon dioxide thereby providing at least one product.
Claim 28
Dependent Claim
32 words
Apparatus as described in claim 24 in which the first electron transfer means is a membrane having photosensitizers, and the second electron transfer means is a membrane having photosensitizers and a catalyst.
Claim 29
Dependent Claim
42 words
Apparatus as described in claim 25 in which the first redox coupled electrolyte solution is selected from the group of redox couples consisting of H 2 O/O 2 , Br - /Br 2 , methylene blue, Fe +2 /Fe +3 and EDTA.
Claim 30
Dependent Claim
37 words
Apparatus as described in claim 26 in which the first membrane's photosensitizer is selected from the group of photosensitizers consisting of n-TiO 2 , n-Fe 2 O 3 , n-WSe 2 , p-InP, methylene blue and porphyrins.
Claim 31
Dependent Claim
39 words
Apparatus as described in claim 27 in which the second redox coupled electrolyte solution is selected from the group of redox couples consisting of I - /I 2 , S 2- /S n 2- , triethanolamine and methyl viologen.
Claim 32
Dependent Claim
37 words
Apparatus as described in claim 28 in which the second membrane's photosensitizer is selected from the group of photosensitizers consisting of p-InP, p-WSe 2 , p-GaAs, p-CdTe, n-WSe 2 , n-CdSe, Ru(bipy) 3 Cl 2 and phthalocyanines.
Claim 33
Dependent Claim
62 words
Apparatus as described in claim 29 in which the catalyst is on the surface of the second membrane that is in contact with the carbon dioxide and is selected from the group of catalysts consisting of dichalcogenides (Ni, Co, Mo, W), SrTiO 3 , NADPH, metal coatings (Pb, In), amalgams (Ni, Zn), chrysene, ethyl acrylate, phthalocyanines (Ni, Co), porphyrins and methyl viologen.
Claim 34
Dependent Claim
37 words
Apparatus as described in claim 30 in which a biasing voltage is provided across the first electrolyte solution and the water in a manner so that the water is anodically biased relative to the first electrolyte solution.
Claim 35
Dependent Claim
17 words
Apparatus as described in claim 31 in which the illumination includes exposing both membranes to solar radiation.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-17 | 1988-12-17 | 1989-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-17 | 1992-12-17 | 1993-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-17 | 1996-12-17 | 1997-06-18 | $7700.00 | Window Closed / Lapsed |