US5260640A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and system for producing electrical power
Assignee: United States Department of Energy
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Filing: 1992-12-08
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Granted: 1993-11-09
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Expires: 2012-12-08
Abstract
Abstract A method and system for converting the chemical energy of methane to electrical energy. Methane is thermally decomposed to hydrogen and carbon in a decomposing unit at a temperature not less than about 1200 DEG K. and at a pressure at least slightly above atmospheric pressure. Carbon and substantially pure oxygen and a cesium or potassium seed material is transmitted to a combustor which is maintained at a pressure of at least about 50 atmospheres to combust the carbon and oxygen and provide an ionized plasma having a temperature not less than about 2800 DEG K. The ionized plasma is accelerated to a velocity not less than about 1000 m/sec and transported through an MHD generator having a magnetic field in the range of from about 4 to about 6 Tesla to generate dc power. The ionized plasma is de-accelerated and passed from the MHD generator in heat exchange relationship with the methane to heat same for decomposition and or reaction, and thereafter any cesium or potassium seed material is recovered and transported to the combustor, and the dc power from the MHD generator is converted to ac power.
Inventors
- 👤 Ralph A. Carabetta
- 👤 Gary E. Staats
- 👤 John C. Cutting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:45
CPC Classifications
H; H02; H02K; H02K44/00; H02K44/08; Y; Y02; Y02E; Y02E20/00; Y02E20/34
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
205 words
A method of converting chemical energy of methane to electrical energy, comprising reacting steam and the methane to form hydrogen and carbon monoxide at an elevated temperature and at an elevated pressure not less than about 50 atmospheres, transmitting the carbon monoxide to a MHD combustor, introducing substantially pure oxygen and a cesium or potassium seed material to the MHD combustor and maintaining the seed material with the carbon monoxide at a pressure of at least about 50 atmospheres to combust the carbon monoxide and the oxygen to provide an ionized plasma having a temperature not less that about 2800° K. accelerating the ionized plasma to a velocity not less than about 1000 m/sec and transporting the ionized plasma through an MHD generator having a magnetic field in the range of from about 4 to about 6 Tesla to generate dc power, de-accelerating the ionized plasma and passing the ionized plasma from the MHD generator in heat exchange relationship with methane and with water to create the steam for the methane-steam reaction, recovering the cesium or potassium seed material and transporting the seed material to the combustor, and collecting the dc power from the MHD generator as at least a portion of the electrical energy.
Claim 2
Independent Claim
205 words
A method of converting chemical energy of methane to electrical energy, comprising reacting steam and the methane to form hydrogen and carbon monoxide at an elevated temperature and at an elevated pressure not less than about 50 atmospheres, transmitting the carbon monoxide to a MHD combustor, introducing substantially pure oxygen and a cesium or potassium seed material to the MHD combustor and maintaining the seed material with the carbon monoxide at a pressure of at least about 50 atmospheres to combust the carbon monoxide and the oxygen to provide an ionized plasma having a temperature not less that about 2800° K. accelerating the ionized plasma to a velocity not less than about 1000 m/sec and transporting the ionized plasma through an MHD generator having a magnetic field in the range of from about 4 to about 6 Tesla to generate dc power, de-accelerating the ionized plasma and passing the ionized plasma from the MHD generator in heat exchange relationship with methane and with water to create the steam for the methane-steam reaction, recovering the cesium or potassium seed material and transporting the seed material to the combustor, and collecting the dc power from the MHD generator as at least a portion of the electrical energy.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein the hydrogen from the methane-steam reaction is transmitted to a fuel cell as fuel to produce dc power.
Claim 4
Dependent Claim
25 words
The method of claim 2, wherein the fuel cell is selected from one of a solid oxide fuel cell and a molten carbonate fuel cell.
Claim 5
Dependent Claim
19 words
The method of claim 2, and further comprising combusting additional methane to provide additional heat for the methane-steam reaction.
Claim 6
Dependent Claim
32 words
The method of claim 2, wherein the methane-steam reaction occurs at a temperature of about 1000° K. and at a pressure in the range of from about 50 to about 100 atmospheres.
Claim 7
Dependent Claim
15 words
The method of claim 4, wherein the combustion of the additional methane is with air.
Claim 8
Dependent Claim
39 words
The method of claim 1, wherein the MHD combustor is operated at a pressure of about 100 atmospheres and a stagnation temperature of about 3600° K. with the stoichiometry of the carbon monoxide and the oxygen being about 1.
Claim 9
Dependent Claim
33 words
The method of claim 1, wherein the MHD generator is operated with an inlet temperature of about 2800° K. and pressure of about 10 atmospheres, the ionized plasma velocity being about 2000 m/sec.
Claim 10
Dependent Claim
18 words
The method of claim 2, wherein the fuel cell is operated at a temperature of about 1000° K.
Claim 11
Dependent Claim
192 words
A sytem for converting chemical energy of methane to electrical energy, comprising a combination methane reformer and steam generator and heat exchange unit for heating water to create steam and for reacting the steam and the methane to produce carbon monoxide and hydrogen and for heating substantially pure oxygen, a MHD combustion unit for combusting the carbon monoxide with the substantially pure heated oxygen and a potassium or cesium seed material to produce an ionized plasma, gases resulting from the reactions, having a temperature not less than about 2800° K., an MHD generator for accelerating the gases to a velocity of not less than about 1000 m/sec and having a magnetic field in the range of from about 4 to about 6 Tesla to produce dc power, means for transmitting the gases leaving the MHD generator to the combination methane reformer and steam generator and heat exchange unit to pass the gases in heat exchange relationship with the methane and the water and the oxygen to heat the methane, water and oxygen, and means for collecting the dc power from said MHD generator as at least a portion of the electric energy.
Claim 12
Dependent Claim
192 words
A sytem for converting chemical energy of methane to electrical energy, comprising a combination methane reformer and steam generator and heat exchange unit for heating water to create steam and for reacting the steam and the methane to produce carbon monoxide and hydrogen and for heating substantially pure oxygen, a MHD combustion unit for combusting the carbon monoxide with the substantially pure heated oxygen and a potassium or cesium seed material to produce an ionized plasma, gases resulting from the reactions, having a temperature not less than about 2800° K., an MHD generator for accelerating the gases to a velocity of not less than about 1000 m/sec and having a magnetic field in the range of from about 4 to about 6 Tesla to produce dc power, means for transmitting the gases leaving the MHD generator to the combination methane reformer and steam generator and heat exchange unit to pass the gases in heat exchange relationship with the methane and the water and the oxygen to heat the methane, water and oxygen, and means for collecting the dc power from said MHD generator as at least a portion of the electric energy.
Claim 13
Dependent Claim
67 words
The system of claim 10, further comprising a source of the substantially pure oxygen, a fuel cell operatively connected to said combination unit and said oxygen source for receiving the hydrogen produced from the methane reformation and the oxygen for producing the dc power for transmission to said inverter and means in communication with the gases for recovering the material for transportation to said MHD combustion unit.
Claim 14
Dependent Claim
26 words
The system of claim 11, and further comprising an auxiliary combustion unit for combusting a portion of the methane to add heat to said combination unit.
Claim 15
Dependent Claim
23 words
The method of claim 2 wherein the dc power from the MHD generator and from the fuel cell is converted to ac power.
Claim 16
Dependent Claim
30 words
The method of claim 11 wherein the dc power from the MHD generator and from the fuel cell is connected to an inverter for converting dc power to ac power.
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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) | 1996-11-08 | 1997-05-10 | 1997-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-08 | 2001-05-10 | 2001-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-08 | 2005-05-10 | 2005-11-09 | $7700.00 | Window Closed / Lapsed |