US4936088A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low NOX cogeneration process
Assignee: PETROCON ENGINEERING Inc
•
Filing: 1988-10-03
•
Granted: 1990-06-26
•
Expires: 2008-10-03
Abstract
Abstract A process for low NOX cogeneration to produce electricity and heat which involves combusting fuel to produce a gaseous stream of combustion products, passing the gaseous stream through a turbine to generate electricity, and to produce a gaseous exhaust stream, adding additional fuel to the exhaust stream, to provide a fuel-rich gas stream having fuel in excess of the oxygen in the combustible gas stream, treating the fuel-rich gas stream in a reducing atmosphere to produce a heated oxygen-depleted gaseous stream, converting at least a portion of the heat in the oxygen depleted stream into steam, adding air to the oxygen-depleted stream to produce a stoichiometric excess of oxygen in the resultant stream relative to fuel present in the resultant stream, passing the resultant stream over an oxidizing catalyst to produce an oxidized gaseous stream, removing heat from the oxidized stream, and venting the resultant cooled stream, the process further providing for cycling to the combusting step at least some of the oxidized gaseous stream. An apparatus system for carrying out this process is also provided.
Inventors
- 👤 Ronald D. Bell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:59
CPC Classifications
F; F23; F23G; F23G5/00; F23G5/44; F23G5/46; F01; F01K; F01K23/00; F01K23/02; F01K23/06; F01K23/10; F01K23/103; F22; F22B; F22B1/00; F22B1/02; F22B1/18; F22B1/1861; F23C; F23C6/00; F23C6/04; F23C6/042; F23C9/00; F23G5/006; F23J; F23J15/00; F23J15/006; F23G2900/00; F23G2900/00001; F23J2215/00; F23J2215/20; F23J2215/60; F23J2219/00; F23J2219/10; Y; Y02; Y02E; Y02E20/00; Y02E20/12
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
163 words
A process for low NOX cogeneration to produce electricity and heat which comprises combusting fuel to produce a gaseous stream of combustion products, passing said gaseous stream through a turbine to generate electricity, and to produce a gaseous exhaust stream, adding additional fuel to said exhaust stream, to provide a fuel-rich gas stream having fuel in excess of the oxygen in said fuel-rich gas stream, treating said combustible gas stream in a reducing atmosphere to produce a heated oxygen-depleted gaseous stream, converting at least a portion of the heat in said oxygen-depleted stream into steam, adding air to said oxygen-depleted stream to produce a stoichiometric excess of oxygen in the resultant stream relative to fuel present in said resultant stream, passing said resultant stream over an oxidizing catalyst to produce an oxidized gaseous stream, removing heat from said oxidized stream, and venting the resultant cooled stream, cycling a stream consisting of at least a portion of said oxidized stream to said combusting step.
Claim 2
Dependent Claim
163 words
A process for low NOX cogeneration to produce electricity and heat which comprises combusting fuel to produce a gaseous stream of combustion products, passing said gaseous stream through a turbine to generate electricity, and to produce a gaseous exhaust stream, adding additional fuel to said exhaust stream, to provide a fuel-rich gas stream having fuel in excess of the oxygen in said fuel-rich gas stream, treating said combustible gas stream in a reducing atmosphere to produce a heated oxygen-depleted gaseous stream, converting at least a portion of the heat in said oxygen-depleted stream into steam, adding air to said oxygen-depleted stream to produce a stoichiometric excess of oxygen in the resultant stream relative to fuel present in said resultant stream, passing said resultant stream over an oxidizing catalyst to produce an oxidized gaseous stream, removing heat from said oxidized stream, and venting the resultant cooled stream, cycling a stream consisting of at least a portion of said oxidized stream to said combusting step.
Claim 3
Dependent Claim
21 words
A process as defined in claim 1, wherein said gaseous exhaust stream is at a temperature of 775° to 1050° F.
Claim 4
Dependent Claim
35 words
A process as defined in claim 1, wherein said fuel is added to said gaseous exhaust in an amount 10% to 25% stoichiometrically in excess of the oxygen present in the resultant combustible gas stream.
Claim 5
Dependent Claim
25 words
A process as defined in claim 1, wherein said combustible gas stream is treated by combusting it at a temperature of 2000 to 3000° F.
Claim 6
Dependent Claim
21 words
A process as defined in claim 4 wherein said combustible gas stream has a residence time 0.5 seconds during its combustion.
Claim 7
Dependent Claim
19 words
A process as defined in claim 1 wherein said fuel-rich stream is treated by means of a reducing catalyst.
Claim 8
Dependent Claim
28 words
A process as defined in claim 1, wherein said oxygen-depleted stream is cooled to a temperature of about 500-600° F. during said conversion of the heat to steam.
Claim 9
Dependent Claim
28 words
A process as defined in claim 1, wherein the space velocity of said resultant stream passing over said oxidizing catalyst is about 30,000 to 50,000 hr. -1 .
Claim 10
Dependent Claim
35 words
A process as defined in claim 1, wherein said air is added to said oxygen-depleted stream in an amount to provide a stoichiometric excess of oxygen present in the resultant stream of 10 to 25%.
Claim 11
Dependent Claim
25 words
A process as defined in claim 1, wherein the cooled gas vented to the atmosphere is at a temperature of about 350 to 500° F.
Claim 12
Dependent Claim
23 words
A process as defined in claim 1, wherein the cooled gas vented to the atmosphere has a NOX content less than 50 ppm.
Claim 13
Dependent Claim
17 words
A process as defined in claim 1, wherein said cycled stream is 60-65% of said oxidized stream.
Claim 14
Independent Claim
233 words
A system for low NOX cogeneration to produce electricity and heat which comprises means for combusting fuel to produce a gaseous stream of combustion products, a turbine connected to generate electricity, conduit means for passing said gaseous stream through said turbine to effect generation of electricity, conduit means for passing the gaseous exhaust stream from said turbine, means for adding additional fuel to said exhaust stream to provide a fuel-rich gas stream having fuel in excess of the oxygen in said combustible gas stream, means for treating said fuel-rich gas stream in a reducing atmosphere to produce a heated oxygen-depleted gaseous stream, means for converting at least a portion of the heat in the gaseous stream treated in said treating means into steam, means for adding air to said last-named stream to produce a stoichiometric excess of oxygen in the resultant stream relative to fuel present in said resultant stream, gas passage means containing an oxidizing catalyst, conduit means for passing said resultant stream into said gas passage means and over said oxidizing catalyst to produce an oxidized gaseous stream, means for removing heat from said oxidized stream, conduit means for passing said oxidized gaseous stream from said gas passage means to said means for removing heat, a vent, a gas conduit connecting said means for removing heat to said vent, and means for cycling said oxidized gaseous stream to said combusting means.
Claim 15
Independent Claim
233 words
A system for low NOX cogeneration to produce electricity and heat which comprises means for combusting fuel to produce a gaseous stream of combustion products, a turbine connected to generate electricity, conduit means for passing said gaseous stream through said turbine to effect generation of electricity, conduit means for passing the gaseous exhaust stream from said turbine, means for adding additional fuel to said exhaust stream to provide a fuel-rich gas stream having fuel in excess of the oxygen in said combustible gas stream, means for treating said fuel-rich gas stream in a reducing atmosphere to produce a heated oxygen-depleted gaseous stream, means for converting at least a portion of the heat in the gaseous stream treated in said treating means into steam, means for adding air to said last-named stream to produce a stoichiometric excess of oxygen in the resultant stream relative to fuel present in said resultant stream, gas passage means containing an oxidizing catalyst, conduit means for passing said resultant stream into said gas passage means and over said oxidizing catalyst to produce an oxidized gaseous stream, means for removing heat from said oxidized stream, conduit means for passing said oxidized gaseous stream from said gas passage means to said means for removing heat, a vent, a gas conduit connecting said means for removing heat to said vent, and means for cycling said oxidized gaseous stream to said combusting means.
Claim 16
Dependent Claim
16 words
A system as defined in claim 13, wherein said means for removing heat is an economizer.
Claim 17
Dependent Claim
13 words
A system as defined in claim 13, wherein said vent is a stack.
Claim 18
Dependent Claim
14 words
A system as defined in claim 13, wherein said converting means is a boiler.
References Cited (Backward Citations)
US4204401A
Cited
US4257223A
Cited
US4375949A
Cited
US4405587A
Cited
US4459126A
Cited
US4594850A
Cited
US4572110A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-25 | 1993-12-25 | 1994-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-25 | 1997-12-25 | 1998-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-25 | 2001-12-25 | 2002-06-26 | $7700.00 | Window Closed / Lapsed |