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US 6,007,699 AGranted
Autothermal methods and systems for fuels conversion
AssigneeEnergy and Environmental Research Corporation
InventorJerald A. Cole
Life of this patent
Estimating the term…
Abstract
A process for oxidizing fuel and transferring the heat produced to a particular use in a combustion system such as fuels conversion. A bed of a mixture of materials forming an unmixed combustion catalyst, which in an oxidized state is readily reducible and in a reduced state is readily oxidizable, is placed in efficient thermal contact with a heat receiver for use in the combustion system. Fuel and air are alternately contacted with the bed, whereby the fuel is oxidized, the air is depleted of oxygen, and heat is liberated. The heat is efficiently transferred to the heat receiver by careful selection of the materials of the bed such that the temperatures produced when the fuel is oxidized and when the air is depleted of oxygen are advantageous to the particular use in the combustion system.
Claims34
A method of generating and transferring heat in an unmixed combustion system, comprising the steps of:
- (a) providing a catalyst for unmixed combustion which in a reduced state is readily oxidized and in an oxidized state is readily reduced, the catalyst comprising at least one catalyst material having an oxidizable form and a reducible form which is selected from the group consisting of tin/tin oxide, iron(II) oxide/iron(III) oxide iron(II) oxide/iron(II,III) oxide, iron (II,III) oxide/iron(III) oxide, cobalt(II,III) oxide/cobalt(IV) oxide, chromium(III) oxide/chromium(IV) oxide, manganese(II,III) oxide/manganese(IV) oxide, calcium molybdite/calcium molybdate, and combinations thereof the catalyst material selected such that:
- (i) heat resulting during an oxidation cycle of the catalyst is in a first temperature range useful in operating the combustion system;
- and
- (ii) heat resulting during a reduction cycle of the catalyst is in a second temperature range useful in operating the combustion system;
- (b) placing the catalyst in efficient thermal contact with a heat receiver in the combustion system;
- and
- (c) contacting the catalyst, to release and transfer heat to the heat receiver, alternately with:
- (i) an oxygen-containing gas to oxidize the catalyst and generate heat in the first temperature range;
- and
- (ii) a reducing gas to reduce the catalyst in a reaction that is exothermic, endothermic, or thermoneutral as required to generate or absorb heat to produce the second temperature range.
7 more elements
An unmixed combustion system for generating and transferring heat, comprising:
- (a) a catalyst for unmixed combustion which in a reduced state is readily oxidized and in an oxidized state is readily reduced, the catalyst comprising a mixture of at least two materials each of which has an oxidizable form and a reducible form, the mixture of materials selected such that:
- (i) heat resulting during an oxidation cycle of the catalyst is in a first temperature range useful in operating the combustion system, the first temperature range during the oxidation cycle being from about 900.degree. C. to about 1100.degree. C.;
- and
- (ii) heat resulting during a reduction cycle of the catalyst is in a second temperature range useful in operating the combustion system, the second temperature range during the reduction cycle being from about 600.degree. C. to about 950.degree. C.;
- (b) a heat receiver in efficient thermal contact with the catalyst;
- and
- (c) means for contacting the catalyst, to release and transfer heat to the heat receiver, alternately with:
- (i) an oxygen-containing gas to oxidize the catalyst and generate heat in the first temperature range;
- and
- (ii) a reducing gas to reduce the catalyst in a reaction that is exothermic, endothermic, or thermoneutral as required to generate or absorb heat to produce the second temperature range.
7 more elements
An unmixed combustion system for generating and transferring heat, comprising:
- (a) a catalyst for unmixed combustion which in a reduced state is readily oxidized and in an oxidized state is readily reduced, the catalyst comprising at least one catalyst material having an oxidizable form and a reducible form which is selected from the group consisting of tin/tin oxide, iron(II) oxide/iron(III) oxide, iron(II) oxide/iron(II,III) oxide, iron (II,III) oxide/iron(III) oxide, cobalt(II,III) oxide/cobalt(IV) oxide, chromium(III) oxide/chromium(IV) oxide, manganese(II,III) oxide/manganese(IV) oxide, calcium molybdite/calcium molybdate, and combinations thereof, the catalyst material selected such that:
- (i) heat resulting during an oxidation cycle of the catalyst is in a first temperature range useful in operating the combustion system;
- and
- (ii) heat resulting during a reduction cycle of the catalyst is in a second temperature range useful in operating the combustion system;
- (b) a heat receiver in efficient thermal contact with the catalyst;
- and
- (c) means for contacting the catalyst, to release and transfer heat to the heat receiver, alternately with:
- (i) an oxygen-containing gas to oxidize the catalyst and generate heat in the first temperature range;
- and
- (ii) a reducing gas to reduce the catalyst in a reaction that is exothermic, endothermic, or thermoneutral as required to generate or absorb heat to produce the second temperature range.
7 more elements
A method of generating and transferring heat in an unmixed combustion system, comprising the steps of:
- (a) providing a mixture of two or more materials, each of which has an oxidizable form and a reducible form, to form a catalyst for unmixed combustion which in a reduced state is readily oxidized and in an oxidized state is readily reduced, the mixture of materials including nickel/nickel oxide and at least one material selected from the group consisting of tin/tin oxide, chromium(III) oxide/chromium(IV) oxide, iron(II) oxide/iron(III) oxide, iron(II) oxide/iron(II,III) oxide, iron (II,III) oxide/iron(III) oxide, cobalt(II,III) oxide/cobalt(IV) oxide, manganese(II,III) oxide/manganese(IV) oxide, and calcium molybdite/calcium molybdate, the mixture of materials selected such that:
- (i) heat resulting during an oxidation cycle of the catalyst is in a first temperature range useful in operating the combustion system;
- and
- (ii) heat resulting during a reduction cycle of the catalyst is in a second temperature range useful in operating the combustion system;
- (b) placing the catalyst in efficient thermal contact with a heat receiver in the combustion system, the heat receiver comprising calcium oxide;
- and
- (c) contacting the catalyst, to release and transfer heat to the heat receiver, alternately with:
- (i) an oxygen-containing gas to oxidize the catalyst and generate heat in the first temperature range;
- and
- (ii) a reducing gas to reduce the catalyst in a reaction that is exothermic, endothermic, or thermoneutral as required to generate or absorb heat to produce the second temperature range, wherein calcium carbonate produced during the reduction of the catalyst is substantially decomposed to calcium oxide and carbon dioxide during oxidation of the catalyst.
7 more elements
An unmixed combustion system for generating and transferring heat, comprising:
- (a) a catalyst for unmixed combustion which in a reduced state is readily oxidized and in an oxidized state is readily reduced, the catalyst comprising a mixture of at least two materials each of which has an oxidizable form and a reducible form, the mixture of materials including nickel/nickel oxide and at least one material selected from the group consisting of tin/tin oxide, chromium(III) oxide/chromium(IV) oxide, iron(II) oxide/iron(III) oxide, iron(II) oxide/iron(II,III) oxide, iron (II,III) oxide/iron(III) oxide, cobalt(II,III) oxide/cobalt(IV) oxide, manganese(II,III) oxide/manganese(IV) oxide, and calcium molybdite/calcium molybdate, the mixture of materials selected such that:
- (i) heat resulting during an oxidation cycle of the catalyst is in a first temperature range useful in operating the combustion system;
- and
- (ii) heat resulting during a reduction cycle of the catalyst is in a second temperature range useful in operating the combustion system;
- (b) a heat receiver in efficient thermal contact with the catalyst the heat receiver comprising calcium oxide;
- and
- (c) means for contacting the catalyst, to release and transfer heat to the heat receiver, alternately with:
- (i) an oxygen-containing gas to oxidize the catalyst and generate heat in the first temperature range;
- and
- (ii) a reducing gas to reduce the catalyst in a reaction that is exothermic, endothermic, or thermoneutral as required to generate or absorb heat to produce the second temperature range, wherein calcium carbonate produced during the reduction of the catalyst is substantially used to calcium oxide and carbon dioxide during oxidation of the catalyst.
7 more elements
A method of generating and transferring heat in an unmixed combustion system, comprising the steps of:
- (a) providing a catalyst for unmixed combustion which in a reduced state is readily oxidized and in an oxidized state is readily reduced, the catalyst comprising:
- (i) a first catalyst material having an oxidizable form and a reducible form selected from the group consisting of silver/silver oxide, copper/copper oxide, iron/iron oxide, cobalt/cobalt oxide, tungsten/tungsten oxide, manganese/manganese oxide, molybdenum/molybdenum oxide, nickel/nickel oxide, tin/tin oxide, strontium sulfide/strontium sulfate, barium sulfide/barium sulfate, iron/iron (II) oxide, iron/iron (III) oxide, iron(II) oxide/iron(III) oxide, iron(II) oxide/iron(II,III) oxide, iron (II,III) oxide/iron(III) oxide, cobalt(II,III) oxide/cobalt(IV) oxide, chromium(III) oxide/chromium(IV) oxide, manganese(II,III) oxide/manganese(IV) oxide, and calcium molybdite/calcium molybdate;
- (ii) a second catalyst material different from the first catalyst material and having an oxidizable form and a reducible form, the second catalyst material selected from the group consisting of tin/tin oxide, iron(II) oxide/iron(III) oxide, iron(II) oxide/iron(II,III) oxide, iron (II,III) oxide/iron(III) oxide, cobalt(II,III) oxide/cobalt(IV) oxide, chromium(III) oxide/chromium(IV) oxide, manganese(II,III) oxide/manganese(IV) oxide, and calcium molybdite/calcium molybdate;
- the first and second catalyst materials selected such that:
- (iii) heat resulting during an oxidation cycle of the catalyst is in a first temperature range useful in operating the combustion system;
- and
- (iv) heat resulting during a reduction cycle of the catalyst is in a second temperature range useful in operating the combustion system;
- (b) placing the catalyst in efficient thermal contact with a heat receiver in the combustion system;
- and
- (c) contacting the catalyst, to release and transfer heat to the heat receiver, alternately with:
- (i) an oxygen-containing gas to oxidize the catalyst and generate heat in the first temperature range;
- and
- (ii) a reducing gas to reduce the catalyst in a reaction that is exothermic, endothermic, or thermoneutral as required to generate or absorb heat to produce the second temperature range.
10 more elements
Dependencies are inferred from the claim text.