GRADUAL OXIDATION AND MULTIPLE FLOW PATHS

• US 20130236372A1
• Filed: 03/09/2012
• Published: 09/12/2013
• Est. Priority Date: 03/09/2012
• Status: Active Grant

• Current Assignee: ReductoNox Corp.
• Original Assignee: FlexEnergy, Inc.
• Inventors: Maslov, Boris A., Denison, Thomas Renau
• Granted Patent: US 8,980,193 B2
• Time in Patent Office: Days
• US Class Current: 422/202
• CPC Class Codes: B01D 2258/05 Biogas
• CPC Class Codes: B01D 53/343 Heat recovery
• CPC Class Codes: F02C 3/22 the fuel or oxidant being gaseous at standard temperature and pressure F02C3/28 takes precedence

Abstract

Described herein are embodiments of systems and methods for oxidizing gases. In some embodiments, a reaction chamber is configured to receive a fuel gas and maintain the gas at a temperature within the reaction chamber that is above an autoignition temperature of the gas. The reaction chamber may also be configured to maintain a reaction temperature within the reaction chamber below a flameout temperature. In some embodiments, heat and product gases from the oxidation process can be used, for example, to drive a turbine, reciprocating engine, and injected back into the reaction chamber.

Claims

1. An oxidizer comprising:

a reaction chamber having an inlet and an outlet, the inlet configured to accept a gas mixture comprising a low-energy-content (LEC) fuel and at least one of the group of a high-energy-content (HEC) fuel, an oxidant-comprising (OC) gas, and a diluent-containing (DC) gas, the gas mixture being at an initial temperature below an autoignition temperature of the gas mixture;

a heat exchange media disposed within the reaction chamber, the media configured (i) to maintain an internal temperature of the reaction chamber below a flameout temperature and (ii) to maintain a reaction chamber inlet temperature to be greater than an autoignition temperature of the mixture; and

a first flow path from the inlet, the first flow path being configured to direct the mixture entering the inlet through media that is hotter than an autoignition temperature of the mixture until the mixture reaches a temperature above the autoignition temperature of the gas mixture, and a second flow path, following the first flow path, the second flow path being configured to direct oxidizing gas mixture to the outlet, the second flow path being generally opposite to the first flow path.

2. The system of claim 1, wherein the reaction chamber is configured to maintain oxidation of the gas mixture along at least one of the first and second flow paths without a catalyst.

3. The system of claim 1, wherein the reaction chamber is configured to maintain oxidation of the mixture beneath the flameout temperature of the gas mixture by circulating heat exchange media outside the reaction chamber.

4. The system of claim 1, further comprising at least one of a turbine or a piston engine that is configured to receive gas from the reaction chamber outlet and expand the gas.

5. The system of claim 1, wherein the gas mixture comprises at least one of hydrogen, methane, ethane, ethylene, natural gas, propane, propylene, propadiene, n-butane, iso-butane, butylene-1, butadiene, iso-pentane, n-pentane, acetylene, hexane, and carbon monoxide.

6. An oxidizer comprising:

a reaction chamber having an inlet and an outlet, the inlet configured to accept a gas mixture comprising a low-energy-content (LEC) fuel and at least one of the group of a high-energy-content (HEC) fuel gas, an oxidant-comprising (OC) gas, and a diluent-containing (DC) gas, the gas mixture being at a temperature below an autoignition temperature of the mixture; and

a heat controller that is configured (i) to increase a temperature of the gas mixture to at least an autoignition temperature of the mixture, thereby permitting the gas mixture to autoignite, and (ii) to maintain the temperature of the gas mixture below a flameout temperature while the autoignited gas mixture oxidizes.

7. The system of claim 6, wherein the heat controller comprises a heat exchanger that is configured to raise the temperature of the mixture to at least the autoignition temperature.

8. The system of claim 7, wherein the heat exchanger is positioned within the reaction chamber.

9. The system of claim 8, wherein the heat exchanger is configured to heat the mixture to above the autoignition temperature after the mixture is within the reaction chamber.

10. The method of claim 6, wherein the reaction chamber is configured to maintain oxidation of the mixture beneath a flameout temperature of the gas mixture without a catalyst.

11. The method of claim 6, further comprising at least one of a turbine or a piston engine that receives gas from the reaction chamber and expands the gas.

12. The method of claim 6, wherein the gas mixture comprises at least one of hydrogen, methane, ethane, ethylene, natural gas, propane, propylene, propadiene, n-butane, iso-butane, butylene-1, butadiene, iso-pentane, n-pentane, acetylene, hexane, and carbon monoxide.

13. An oxidizer comprising:

a reaction chamber having an inlet and an outlet, the inlet configured to accept a first gas mixture comprising a low-energy-content (LEC) fuel and at least one of the group of a high-energy-content (HEC) fuel gas, an oxidant-comprising (OC) gas, and a diluent-containing (DC) gas, the gas mixture being at an initial temperature below an autoignition temperature of the mixture;

a heat controller that is configured to heat the first gas mixture to at least an autoignition temperature of the first gas mixture, such that the first gas mixture autoignites; and

an injector that is configured to inject, after the first gas mixture is heated to at least the autoignition temperature, a second gas mixture comprising a LEC fuel gas and a HEC fuel, wherein the injector injects a ratio of the LEC and HEC gas to form the second gas mixture at a rate of injection that is selected to produce substantially the same ratio of LEC and HEC gas to the second mixture as a ratio of the LEC gas and the at least one of high-energy-content (HEC) fuel gas, an oxidant-comprising (OC) gas, and a diluent-containing (DC) gas to the first gas mixture;

wherein the reaction chamber is configured (i) to mix the injected second gas into the autoignited first gas mixture at a rate to produce a substantially homogeneous third gas mixture in a time less than the autoignition delay time for the second gas mixture and (ii) to maintain a temperature of the first gas mixture below a flameout temperature while the autoignited first gas mixture oxidizes.

14. The system of claim 13, wherein the heat controller comprises a heat exchanger that is configured to raise the temperature of the mixture to at least the autoignition temperature.

15. The system of claim 14, wherein the heat exchanger is positioned within the reaction chamber.

16. The system of claim 13, wherein the reaction chamber is configured to maintain oxidation of the first gas mixture within the reaction chamber without a catalyst.

17. The system of claim 13, wherein the reaction chamber is configured to maintain oxidation of the second gas mixture beneath a flameout temperature of the gas mixture without a catalyst.

18. The system of claim 13, further comprising at least one of a turbine or a piston engine that is configured to receive gas from the reaction chamber and to expand the gas.

19. The system of claim 13, wherein the first gas mixture comprises at least one of hydrogen, methane, ethane, ethylene, natural gas, propane, propylene, propadiene, n-butane, iso-butane, butylene-1, butadiene, iso-pentane, n-pentane, acetylene, hexane, and carbon monoxide.