US3846979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two stage combustion process
Assignee: Engelhard Minerals and Chemicals Corp
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Filing: 1973-08-16
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Granted: 1974-11-12
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Expires: 1993-08-16
Abstract
Abstract A method is disclosed which encompasses a two stage combustion process wherein a carbonaceous fuel, which when burned with stoichiometric amount of air has an adiabatic flame temperature of at least 3,300* F., admixed with air is partially combusted in a thermal zone. The effluent is quenched and then contacted with a solid oxidation catalyst to combust or oxidize the fuel under essentially adiabatic conditions. The operating temperature of the catalyst is preferably substantially above the instantaneous auto-ignition temperature of the fuel-air admixture but below a temperature that would result in any substantial formation of oxides of nitrogen, for example at a temperature of about 1,500* to 3,200* F. The resulting effluent is characterized by high thermal energy useful for generating power and by low amounts of atmospheric pollutants, especially oxides of nitrogen.
Inventors
- 👤 W Pfefferle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:16
CPC Classifications
F; F23; F23R; F23R3/00; F23R3/40
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
91 words
IN A METHOD FOR OXIDIZING CARBONACEOUS FUEL WHICH WHEN BURNED WITH A STOICHIOMETRIC AMOUNT OF AIR HAS AN ADIABATIC FLAME TEMPERATURE OF AT LEAST ABOUT 3,300*F., THE IMPROVEMENT COMPRISING ADMIXING THE CARBONACEOUS FUEL AND AIR, PARTIALLY COMBUSTING THE FUEL IN A THERMAL COMBUSTION ZONE AND PRODUCING AN EFFLUENT CONTAINING PARTIALLY COMBUSTED FULE, IMMEDIATELY QUENCHING SAID EFFLUENT, AND ESSENTIALLY ADIABATICALLY OXIDIZING AT A TEMPERATURE OF ABOUT 1,500* TO 3,200* F. AT LEAST ABOUT 10 PERCENT OF THE FUEL BY CONTACTING THE QUENCHED EFFLUENT CONTAINING PARTIALLY COMBUSTED FUEL WITH A SOLID OXIDATION CATALYST.
Claim 2
Dependent Claim
91 words
IN A METHOD FOR OXIDIZING CARBONACEOUS FUEL WHICH WHEN BURNED WITH A STOICHIOMETRIC AMOUNT OF AIR HAS AN ADIABATIC FLAME TEMPERATURE OF AT LEAST ABOUT 3,300*F., THE IMPROVEMENT COMPRISING ADMIXING THE CARBONACEOUS FUEL AND AIR, PARTIALLY COMBUSTING THE FUEL IN A THERMAL COMBUSTION ZONE AND PRODUCING AN EFFLUENT CONTAINING PARTIALLY COMBUSTED FULE, IMMEDIATELY QUENCHING SAID EFFLUENT, AND ESSENTIALLY ADIABATICALLY OXIDIZING AT A TEMPERATURE OF ABOUT 1,500* TO 3,200* F. AT LEAST ABOUT 10 PERCENT OF THE FUEL BY CONTACTING THE QUENCHED EFFLUENT CONTAINING PARTIALLY COMBUSTED FUEL WITH A SOLID OXIDATION CATALYST.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein the partially combusted effluent is quenched by admixture with additional air.
Claim 4
Dependent Claim
19 words
The method of claim 2 wherein the temperature of said catalytic oxidation catalyst is about 2,000* to 3,000* F.
Claim 5
Dependent Claim
22 words
The method of claim 3 wherein the temperature of the gases from the thermal combustion zone is about 1,800* to 2,800* F.
Claim 6
Dependent Claim
37 words
The method of claim 3 wherein the total amount of the air for thermal combustion and the additional air for quenching is at least about two times the stoichiometric amount needed for complete combustion of the fuel.
Claim 7
Dependent Claim
25 words
The method of claim 1 wherein the carbonaceous fuel is combusted to about 35 to 90 percent of complete oxidation in the thermal combustion zone.
Claim 8
Dependent Claim
19 words
The method of claim 1 wherein the temperature of the thermal combustion zone is about 1,800* to 3,700* F.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein the temperature of the thermal combustion zone is about 1,800* to 2,800* F.
Claim 10
Dependent Claim
22 words
The method of claim 1 wherein the quenched effluent has a theoretical adiabatic flame temperature of about 1,500* to 3, 200* F.
Claim 11
Dependent Claim
156 words
In a method for operating a gas turbine which comprises oxidizing a carbonaceous fuel, which when burned with a stoichiometric amount of air has an adiabatic flame temperature of at least about 3,300* F., and air to produce a motive fluid for rotating the turbine, the improvement comprising admixing the carbonaceous fuel and air, partially combusting the fuel in a thermal combustion zone to about 35 to 90 percent of complete oxidation and producing an effluent containing partially combusted fuel, immediately quenching said effluent with air in excess of the stoichiometric amount sufficient to completely oxidize the partially combusted fuel, essentially adiabatically oxidizing at a temperature of about 2,000* to 3,000* F. in a catalytic oxidation zone at least about 10 percent of the fuel by contacting the quenched effluent containing partially combusted fuel with a solid oxidation catalyst, and passing the effluent from the catalytic oxidation zone through a gas turbine to rotate the turbine.
Claim 12
Dependent Claim
156 words
In a method for operating a gas turbine which comprises oxidizing a carbonaceous fuel, which when burned with a stoichiometric amount of air has an adiabatic flame temperature of at least about 3,300* F., and air to produce a motive fluid for rotating the turbine, the improvement comprising admixing the carbonaceous fuel and air, partially combusting the fuel in a thermal combustion zone to about 35 to 90 percent of complete oxidation and producing an effluent containing partially combusted fuel, immediately quenching said effluent with air in excess of the stoichiometric amount sufficient to completely oxidize the partially combusted fuel, essentially adiabatically oxidizing at a temperature of about 2,000* to 3,000* F. in a catalytic oxidation zone at least about 10 percent of the fuel by contacting the quenched effluent containing partially combusted fuel with a solid oxidation catalyst, and passing the effluent from the catalytic oxidation zone through a gas turbine to rotate the turbine.
Claim 13
Dependent Claim
18 words
The method of claim 10 wherein the partial combustion effluent is further quenched by contact with said catalyst.
Claim 14
Dependent Claim
27 words
The method of claim 10 in which the weight ratio of air to partially combusted fuel in the admixture prior to catalytic combustion is above about 20:1.
Claim 15
Dependent Claim
19 words
The method of claim 10 wherein the temperature of the thermal combustion zone is about 1,800* to 3,700* F.
Claim 16
Dependent Claim
19 words
The method of claim 10 wherein the temperature of the thermal combustion zone is about 1,800* to 2,800* F.
Claim 17
Dependent Claim
132 words
In a method for operating a gas turbine which comprises oxidizing a carbonaceous fuel, which when burned with a stoichiometric amount of air has an adiabatic flame temperature of at least about 3,300* F., and air to provide a motive fluid for rotating the turbine, the improvement comprising admixing the carbonaceous fuel and air, partially combusting the fuel in a thermal combustion zone and producing an effluent containing partially combusted fuel, immediately quenching said effluent, essentially adiabatically oxidizing at a temperature of about 1, 500* to 3,200* F. in a catalytic oxidation zone at least about 10 percent of the fuel by contacting the quenched effluent containing partially combusted fuel with a solid oxidation catalyst, and passing the effluent from the catalytic oxidation zone through a gas turbine to rotate the turbine.
Claim 18
Dependent Claim
132 words
In a method for operating a gas turbine which comprises oxidizing a carbonaceous fuel, which when burned with a stoichiometric amount of air has an adiabatic flame temperature of at least about 3,300* F., and air to provide a motive fluid for rotating the turbine, the improvement comprising admixing the carbonaceous fuel and air, partially combusting the fuel in a thermal combustion zone and producing an effluent containing partially combusted fuel, immediately quenching said effluent, essentially adiabatically oxidizing at a temperature of about 1, 500* to 3,200* F. in a catalytic oxidation zone at least about 10 percent of the fuel by contacting the quenched effluent containing partially combusted fuel with a solid oxidation catalyst, and passing the effluent from the catalytic oxidation zone through a gas turbine to rotate the turbine.
Claim 19
Dependent Claim
25 words
The method of claim 15 wherein the carbonaceous fuel is combusted to about 35 to 90 percent of complete oxidation in the thermal combustion zone.
Claim 20
Independent Claim
121 words
A method for the catalytically-supported thermal combustion of carbonaceous fuel comprising: a. thermally oxidizing a carbonaceous fuel-air mixture to produce a partially oxidized vaporous effluent having a stoichiometric excess of air; b. quenching said effluent; and c. contacting said quenched, partially oxidized effluent with a solid oxidation catalyst to combust said partially oxidized effluent under essentially adiabatic conditions to form a final effluent of high thermal energy; said combustion being characterized by said partially oxidized effluent having an adiabatic flame temperature such that upon contact with said catalyst, the operating temperature of said catalyst is substantially above the instantaneous auto-ignition temperature of said partially oxidized effluent but below a temperature that would result in any substantial formation of oxides of nitrogen.
Claim 21
Independent Claim
121 words
A method for the catalytically-supported thermal combustion of carbonaceous fuel comprising: a. thermally oxidizing a carbonaceous fuel-air mixture to produce a partially oxidized vaporous effluent having a stoichiometric excess of air; b. quenching said effluent; and c. contacting said quenched, partially oxidized effluent with a solid oxidation catalyst to combust said partially oxidized effluent under essentially adiabatic conditions to form a final effluent of high thermal energy; said combustion being characterized by said partially oxidized effluent having an adiabatic flame temperature such that upon contact with said catalyst, the operating temperature of said catalyst is substantially above the instantaneous auto-ignition temperature of said partially oxidized effluent but below a temperature that would result in any substantial formation of oxides of nitrogen.
Claim 22
Dependent Claim
49 words
A method as defined in claim 17 wherein said quenching is accomplished by introducing air into said partially oxidized effluent, said air being present in a sufficient amount to insure a stoichiometric excess thereof and being at a temperature sufficiently low to insure incomplete combustion of said carbonaceous fuel.
Claim 23
Dependent Claim
25 words
A method as defined in claim 17 further comprising the additional step of introducing fuel into said effluent to increase the adiabatic flame temperature thereof.
Claim 24
Dependent Claim
34 words
A method as defined in claim 17 further comprising the step of adding air to said final effluent, said air having a temperature lower than that of said final effluent, thereby cooling said effluent.
Claim 25
Dependent Claim
16 words
A method as defined in claim 17 wherein said final effluent is employed to produce power.
Claim 26
Dependent Claim
18 words
A method as defined in claim 17 wherein said adiabatic flame temperature is about 1,500* to 3,200* F.
Claim 27
Dependent Claim
32 words
A method as defined in claim 17 wherein said quenched partially oxidized effluent contains at least about 1.5 times the stoichiometric amount of oxygen based on complete combustion of said carbonaceous fuel.
Claim 28
Dependent Claim
26 words
A method as defined in claim 17 wherein the residence time of said quenched, partially oxidized effluent undergoing catalytic combustion is less than about 0.05 second.
Claim 29
Independent Claim
143 words
A method for operating a gas turbine by the catalytically-supported thermal combustion of carbonaceous fuel comprising: a. thermally oxidizing a carbonaceous fuel-air mixture to produce a partially oxidized vaporous effluent having a stoichiometric excess of air; b. quenching said effluent; c. contacting said quenched, partially oxidized effluent with a solid oxidation catalyst to combust said partially oxidized effluent under essentially adiabatic conditions to form a final effluent of high thermal energy, said combustion being characterized by said partially oxidized effluent having an adiabatic flame temperature such that upon contact with said catalyst, the operating temperature of said catalyst is substantially above the instantaneous auto-ignition temperature of said partially oxidized effluent but below a temperature that would result in any substantial formation of oxides of nitrogen; and d. passing said final effluent from said catalytic combustion through a gas turbine to cause rotary motion.
Claim 30
Independent Claim
143 words
A method for operating a gas turbine by the catalytically-supported thermal combustion of carbonaceous fuel comprising: a. thermally oxidizing a carbonaceous fuel-air mixture to produce a partially oxidized vaporous effluent having a stoichiometric excess of air; b. quenching said effluent; c. contacting said quenched, partially oxidized effluent with a solid oxidation catalyst to combust said partially oxidized effluent under essentially adiabatic conditions to form a final effluent of high thermal energy, said combustion being characterized by said partially oxidized effluent having an adiabatic flame temperature such that upon contact with said catalyst, the operating temperature of said catalyst is substantially above the instantaneous auto-ignition temperature of said partially oxidized effluent but below a temperature that would result in any substantial formation of oxides of nitrogen; and d. passing said final effluent from said catalytic combustion through a gas turbine to cause rotary motion.
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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |