Recycling of carbon dioxide into methyl alcohol and related oxygenates for hydrocarbons

• US 5,928,806 A
• Filed: 05/05/1998
• Issued: 07/27/1999
• Est. Priority Date: 05/07/1997
• Status: Expired due to Term

• Current Assignee: University of Southern California
• Original Assignee: George A. Olah, Prakash G K Surya
• Inventors: Prakash, G. K. Surya, Olah, George A.
• Primary Examiner(s): KALAFUT, STEPHEN J
• Application Number:
  US09/072,585
• Time in Patent Office: 448 Days
• Field of Search: 429/13, 429/21, 204/DIG. 4
• US Class Current: 429/418
• CPC Class Codes: C25B 3/25 Reduction
• CPC Class Codes: H01M 8/06 Combination of fuel cells with means for production of reactants or for treatment of residues regenerative fuel cells H01M8/18
• CPC Class Codes: H01M 8/184 Regeneration by electrochemical means
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 204/04 Electrolysis cell combined with fuel cell

Abstract

A regenerative electrochemical cell system based on a fuel cell to oxidize methyl alcohol or other oxygenated hydrocarbons coupled with a regenerative cell to reduce carbon dioxide to form oxygenated hydrocarbons is disclosed. Methods to reversibly interconvert oxygenated hydrocarbons and carbon dioxide, to recycle carbon dioxide produced as a by-product of industrial processes, and to store and release electrical and chemical energy are also disclosed.

Claims

1. A regenerative fuel cell system comprising:

a first electrochemical cell to oxidize an oxygenated hydrocarbon to carbon dioxide and water and having electrical output means for recovering electrical energy produced thereby; and

a second electrochemical cell to reduce carbon dioxide and water to the oxygenated hydrocarbon and oxygen and having electrical input means for providing electrical energy thereto;

wherein the first and second electrochemical cells are in fluid communication with each other such that the carbon dioxide and water produced in the first cell are provided to the second cell, and the oxygenated hydrocarbon and oxygen produced in the second cell are provided to the first cell.

2. The regenerative fuel cell system of claim 1, wherein the first electrochemical cell is a liquid feed fuel cell.

3. The regenerative fuel cell system of claim 1, wherein the second electrochemical cell is a reversed liquid feed fuel cell.

4. The regenerative fuel cell system of claim 1, which further comprises first transfer means to add or remove components to or from the first electrochemical cell, and second transfer means to add or remove components to or from the second electrochemical cell.

5. A regenerative fuel cell system comprising:

a first electrochemical cell to oxidize a first oxygenated hydrocarbon to carbon dioxide and water and having electrical output means for recovering electrical energy produced thereby; and

a second electrochemical cell to reduce carbon dioxide to a second oxygenated hydrocarbon and oxygen and having electrical input means for providing electrical energy thereto;

wherein the first and second electrochemical cells are in-fluid communication with each other such that the carbon dioxide and water produced in the first cell are provided to the second cell, and the second oxygenated hydrocarbon and oxygen produced in the second cell are provided to the first cell;

wherein the first and second oxygenated hydrocarbons are selected from the group consisting of methyl alcohol, methyl formate, formaldehyde and formic acid.

6. The regenerative fuel cell system of claim 5, which further comprises first transfer means to add or remove components to or from the first electrochemical cell, and second transfer means to add or remove components to or from the second electrochemical cell.

7. A method of reversibly interconverting oxygenated hydrocarbons and carbon dioxide, which comprises:

oxidizing a first oxygenated hydrocarbon to carbon dioxide and water in a first zone; and

reducing a mixture of carbon dioxide and water to a second oxygenated hydrocarbon and oxygen in a second zone,

wherein the first and second zones are in fluid communication with each other such that the carbon dioxide and water produced in the first zone are provided to the second zone, the second oxygenated hydrocarbon and oxygen produced in the second zone are provided to the first zone, and the first and second oxygenated hydrocarbons are selected from the group consisting of methyl alcohol, methyl formate, formaldehyde and formic acid.

8. The method of claim 7, wherein the reducing step consumes electrical energy, and the method further comprises providing electrical energy to the second zone.

9. The method of claim 8, wherein the electrical energy provided to the second zone is obtained from off-peak production of a power plant.

10. The method of claim 7, wherein the oxidizing step produces electrical energy, and the method further comprises recovering the electrical energy thus produced.

11. A method of reversibly interconverting oxygenated hydrocarbons and carbon dioxide, which comprises:

oxidizing a first oxygenated hydrocarbon to carbon dioxide and water in a first zone; and

reducing a mixture of carbon dioxide and water to a second oxygenated hydrocarbon and oxygen in a second zone,

wherein the first and second zones are in fluid communication with each other such that the carbon dioxide and water produced in the first zone are provided to the second zone, the second oxygenated hydrocarbon and oxygen produced in the second zone are provided to the first zone, and the first and second oxygenated hydrocarbons are the same compound.

12. The method of claim 11 wherein the reducing step consumes electrical energy, and the method further comprises providing electrical energy to the second zone.

13. The method of claim 12, wherein the electrical energy provided to the second zone is obtained from off-peak production of a power plant.

14. The method of claim 11, wherein the oxidizing step produces electrical energy, and the method further comprises recovering the electrical energy thus produced.

15. A method of reducing carbon dioxide to form an oxygenated hydrocarbon, which comprises providing carbon dioxide, water and electrical energy to a reduction zone such that the carbon dioxide and water react to form oxygen and an oxygenated hydrocarbon or mixture of oxygenated hydrocarbons wherein the oxygenated hydrocarbon or mixture includes methyl alcohol, formaldehyde, formic acid or methyl formate.

16. The method of claim 15, wherein the carbon dioxide provided to the reduction zone is obtained as an industrial by-product.

17. The method of claim 15, wherein the electrical energy provided to the reduction zone is obtained from off-peak production of a power plant.

18. The method of claim 15, wherein the oxygenated hydrocarbon is methyl alcohol, and the method further comprises dehydrating the methyl alcohol to form dimethyl ether, and dehydrating the dimethyl ether to form ethylene.

19. A method of storing electrical energy as chemical energy and recovering electrical energy from the stored chemical energy, which comprises:

reversibly interconverting oxygenated hydrocarbons and carbon dioxide by oxidizing a first oxygenated hydrocarbon to carbon dioxide and water in a first zone; and

reducing a mixture of carbon dioxide and water to a second oxygenated hydrocarbon and oxygen in a second zones wherein the first and second zones are in fluid communication with each other such that the carbon dioxide and water produced in the first zone are provided to the second zone, and the second oxygenated hydrocarbon and oxygen produced in the second zone are provided to the first zone; and

conducting the oxidizing and reducing steps in an energy storage mode and an energy recovery mode, wherein the energy storage mode comprises providing energy to the second zone, and transferring the second oxygenated hydrocarbon and oxygen thus produced to the first zone; and

wherein the energy recovery mode comprises oxidizing the first oxygenated hydrocarbon in the first zone, transferring the carbon dioxide and water thus produced to the second zone, and recovering the electrical energy thus produced from the second zone.

20. A method of storing electrical energy as chemical energy and recovering electrical energy from the stored chemical energy, which comprises:

providing a regenerative fuel cell system comprising;

a first electrochemical cell to oxidize a first oxygenated hydrocarbon to carbon dioxide and water and having electrical output means for recovering electrical energy produced thereby; and

a second electrochemical cell to reduce carbon dioxide to a second oxygenated hydrocarbon and oxygen and having electrical input means for providing electrical energy thereto;

wherein the first and second electrochemical cells are in fluid communication with each other such that the carbon dioxide and water produced in the first cell are provided to the second cell, and the second oxygenated hydrocarbon and oxygen produced in the second cell are provided to the first cell; and

operating the regenerative fuel cell system in an energy storage mode and an energy recovery mode, wherein the energy storage mode comprises providing electrical energy to the electrical input means of the second electrochemical cell to reduce carbon dioxide therein to the second oxygenated hydrocarbon and oxygen, and transferring the second oxygenated hydrocarbon and oxygen thus produced to the first cell; and

wherein the energy recovery mode comprises oxidizing one of the first or second oxygenated hydrocarbons in the first electrochemical cell to form carbon dioxide and water, transferring the carbon dioxide and water thus produced to the second electrochemical cell, and recovering the electrical energy thus produced from the electrical output means.

21. The method of claim 20 wherein the first and second oxygenated hydrocarbons are the same compound.