Gradual oxidation with heat control

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.

What is claimed is: 
     
         1 . A method for oxidizing fuel, comprising:
 receiving a gas comprising an oxidizable fuel into an oxidizer having a reaction chamber with an inlet and an outlet, the reaction chamber configured to maintain an oxidation process of the gas; and   changing at least one of (i) removal of heat from the reaction chamber and (ii) an inlet temperature of the reaction chamber when at least one of (a) an actual temperature within the reaction chamber approaches or increases to a flameout temperature of the fuel and (b) the reaction chamber inlet temperature approaches or drops below an autoignition threshold of the fuel.   
     
     
         2 . The method of  claim 1 , wherein the actual temperature of the reaction chamber is maintained below the flameout temperature. 
     
     
         3 . The method of  claim 1 , wherein the inlet temperature of the reaction chamber is increased to a level that will support oxidation of the fuel without a catalyst. 
     
     
         4 . The method of  claim 1 , wherein the inlet temperature is increased to above the autoignition threshold. 
     
     
         5 . The method of  claim 1 , wherein a temperature of the gas is increased by a heat exchanger located within the reaction chamber. 
     
     
         6 . The method of  claim 1 , further comprising expanding gas from the reaction chamber outlet in a turbine or a piston engine. 
     
     
         7 . The method of  claim 1 , further comprising compressing the fuel with a compressor prior to introduction of the fuel mixture into the reaction chamber. 
     
     
         8 . The method of  claim 1 , wherein removal of heat from the reaction chamber comprises introducing a liquid into the reaction chamber. 
     
     
         9 . The method of  claim 8 , further comprising evacuating the liquid from the reaction chamber. 
     
     
         10 . The method of  claim 9 , wherein the liquid is evacuated from the reaction chamber in the form of steam. 
     
     
         11 . The method of  claim 1 , wherein the reaction chamber maintains gradual oxidation of the oxidizable fuel without a catalyst. 
     
     
         12 . The method of  claim 1 , wherein heat is removed from the reaction chamber when the temperature within the reaction chamber exceeds 2300° F. 
     
     
         13 . The method of  claim 1 , wherein the oxidizable fuel 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. 
     
     
         14 . A method for oxidizing fuel, comprising:
 receiving a gas comprising an oxidizable fuel into an oxidizer having a reaction chamber with an inlet and an outlet, the reaction chamber configured to maintain a gradual oxidation process; and   increasing at least one of (i) removal of heat from the reaction chamber when an adiabatic reaction temperature within the reaction chamber approaches a flameout temperature of the fuel; and (ii) an inlet temperature of the reaction chamber when the reaction chamber inlet temperature drops below an autoignition threshold of the fuel.   
     
     
         15 . The method of  claim 14 , wherein an actual temperature of the reaction chamber is maintained below the flameout temperature. 
     
     
         16 . The method of  claim 14 , wherein the inlet temperature of the reaction chamber rises to a level that will support oxidation of the fuel without a catalyst. 
     
     
         17 . The method of  claim 14 , wherein the inlet temperature rises above the autoignition temperature. 
     
     
         18 . The method of  claim 14 , wherein a gas temperature is increased by a heat exchanger located outside the reaction chamber, and the gas is passed through the heat exchanger prior to being introduced into the reaction chamber. 
     
     
         19 . A method for oxidizing fuel, comprising:
 receiving a gas comprising an oxidizable fuel into an oxidizer having a reaction chamber with an inlet and an outlet, the reaction chamber configured to maintain a gradual oxidation process without a catalyst; and   increasing at least one of (i) removal of heat from the reaction chamber when a reaction temperature within the reaction chamber approaches a flameout temperature of the fuel, such that an actual temperature of the reaction chamber is maintained below the flameout temperature; and (ii) an inlet temperature of the reaction chamber when the reaction chamber inlet temperature drops below an autoignition threshold of the fuel, such that the inlet temperature of the reaction chamber is maintained above a level that will support oxidation of the fuel without a catalyst.   
     
     
         20 . The method of  claim 19 , wherein the inlet temperature is maintained above the autoignition temperature.