Low Temperature Homogeneous Charge Continuous Oxidation Burner Heat Source

Abstract

A homogeneous charge continuous oxidation system for generating heat can include a fuel gas source, an oxygen source, and a carbon dioxide source. The oxygen source can include oxygen gas that is substantially free of nitrogen or that contains nitrogen in an amount less than 10 vol %. The system can also include an oxidation chamber including an oxidation product outlet and at least one inlet connected to the fuel gas source, the oxygen source, and the carbon dioxide source to receive a gas mixture of fuel gas, oxygen, and carbon dioxide. A body of porous material can be within the oxidation chamber and positioned in a flow path of the gas mixture between the at least one inlet and the oxidation product outlet such that oxidation occurs within the body of porous material.

What is claimed is: 
     
         1 . A homogeneous charge continuous oxidation system for generating heat, comprising:
 a fuel gas source;   an oxygen source comprising oxygen gas that is substantially free of nitrogen or that comprises nitrogen in an amount less than 10 vol %;   a carbon dioxide source;   an oxidation chamber comprising an oxidation product outlet and at least one inlet connected to the fuel gas source, the oxygen source, and the carbon dioxide source to receive a gas mixture of fuel gas, oxygen, and carbon dioxide; and   a body of porous material within the oxidation chamber and positioned in a flow path of the gas mixture between the at least one inlet and the oxidation product outlet such that oxidation occurs within the body of porous material.   
     
     
         2 . The system of  claim 1 , wherein a flow of fuel gas, a flow of oxygen, and a flow of carbon dioxide are independently controllable. 
     
     
         3 . The system of  claim 1 , wherein the fuel gas is substantially free of nitrogen compounds. 
     
     
         4 . The system of  claim 1 , wherein the fuel gas comprises natural gas, methane, hydrogen, hydrocarbons produced from oil shale, or a combination thereof. 
     
     
         5 . The system of  claim 1 , wherein the oxygen source comprises an oxygen concentrator configured to separate oxygen from air. 
     
     
         6 . The system of  claim 1 , wherein the oxygen gas is substantially free of nitrogen. 
     
     
         7 . The system of  claim 1 , further comprising a carbon dioxide recycle stream connected to the oxidation product outlet, wherein the carbon dioxide source comprises recycled carbon dioxide produced from oxidation in the oxidation chamber and recycled through the recycle stream. 
     
     
         8 . The system of  claim 1 , further comprising a carbon dioxide sequestration stream connected to the oxidation product outlet and configured to sequester carbon dioxide produced by the oxidation. 
     
     
         9 . The system of  claim 1 , further comprising a preheater configured to preheat at least one of the fuel gas, oxygen, and carbon dioxide upstream of the body of porous material. 
     
     
         10 . The system of  claim 1 , further comprising a gas mixing chamber connected downstream of the fuel gas source, oxygen source, and carbon dioxide source, and upstream of the oxidation chamber, configured to prepare a homogeneous mixture of fuel gas, oxygen, and carbon dioxide before the gas mixture flows into the oxidation chamber. 
     
     
         11 . The system of  claim 1 , wherein the porous material substantially fills the oxidation chamber. 
     
     
         12 . The system of  claim 1 , wherein the porous material comprises a loose particulate material having an average particle size from about 1 mm to about 20 cm. 
     
     
         13 . The system of  claim 1 , wherein the porous material comprises spent oil shale, rock, alumina beads, metal beads, metal balls, zeolite, ceramic, structured packing, metal screen, ceramic screen, baffles, mesh, or a combination thereof. 
     
     
         14 . The system of  claim 1 , further comprising a heat exchanger connected downstream to the oxidation product outlet, the heat exchanger providing heat to an industrial process. 
     
     
         15 . The system of  claim 1 , further comprising an oil shale pyrolyzing unit connected downstream to the oxidation product outlet, wherein the oxidation products provide heat to pyrolyze oil shale. 
     
     
         16 . A homogeneous charge continuous oxidation method for generating heat, comprising:
 flowing a gas mixture through a body of porous material within an oxidation chamber, wherein the gas mixture comprises a fuel gas, oxygen, and carbon dioxide, and wherein the oxygen is provided from an oxygen source that is substantially free of nitrogen or that comprises nitrogen in an amount less than 10 vol %;   maintaining the body of porous material at a temperature above an oxidation initiation temperature of the gas mixture;   oxidizing of the gas mixture within the body of porous material, thereby generating heat and oxidation products; and   flowing the oxidation products out of the oxidation chamber.   
     
     
         17 . The method of  claim 16 , further comprising independently controlling a concentration of fuel gas, oxygen, and carbon dioxide in the gas mixture. 
     
     
         18 . The method of  claim 16 , wherein the fuel gas comprises natural gas, methane, hydrogen, hydrocarbons produced from oil shale, or a combination thereof. 
     
     
         19 . The method of  claim 16 , further comprising separating the oxygen from air and mixing the oxygen with the fuel gas and the carbon dioxide. 
     
     
         20 . The method of  claim 16 , wherein the oxygen is substantially free of nitrogen. 
     
     
         21 . The method of  claim 16 , wherein the carbon dioxide comprises recycled carbon dioxide produced from oxidation in the oxidation chamber. 
     
     
         22 . The method of  claim 16 , wherein the gas mixture is fuel-rich. 
     
     
         23 . The method of  claim 22 , wherein the fuel gas comprises recycled unburned fuel gas from the oxidation chamber. 
     
     
         24 . The method of  claim 16 , further comprising sequestering carbon dioxide from the oxidation products. 
     
     
         25 . The method of  claim 16 , further comprising preheating the gas mixture before the gas mixture contacts the body of porous material. 
     
     
         26 . The method of  claim 25 , wherein the gas mixture is preheated to a preheat temperature within 50° F. (28° C.) of an oxidation initiation temperature of the gas mixture. 
     
     
         27 . The method of  claim 16 , further comprising preparing the gas mixture by mixing the fuel gas, oxygen, and carbon dioxide in a gas mixing chamber that is upstream of the oxidation chamber. 
     
     
         28 . The method of  claim 16 , wherein the gas mixture is prepared in the oxidation chamber by flowing the fuel gas, oxygen, and carbon dioxide into the oxidation chamber as multiple separate streams and then mixing the fuel gas, oxygen, and carbon dioxide inside the oxidation chamber. 
     
     
         29 . The method of  claim 16 , wherein the porous material substantially fills the oxidation chamber. 
     
     
         30 . The method of  claim 16 , wherein the porous material comprises a loose particulate material having an average particle size from about 1 mm to about 20 cm. 
     
     
         31 . The method of  claim 16 , wherein the porous material comprises spent oil shale, rock, alumina beads, metal beads, metal balls, zeolite, ceramic, structured packing, metal screen, ceramic screen, baffles, mesh, or a combination thereof. 
     
     
         32 . The method of  claim 16 , further comprising providing heat from the oxidation products to an industrial process connected downstream of the oxidation chamber. 
     
     
         33 . The method of  claim 16 , further comprising pyrolyzing oil shale using heat from the oxidation products. 
     
     
         34 . The method of  claim 16 , further comprising controlling a temperature of oxidation in the oxidation chamber by adjusting a concentration of carbon dioxide in the gas mixture. 
     
     
         35 . The method of  claim 16 , wherein an oxidation temperature in the oxidation chamber is from about 700° F. (371° C.) to about 3,000° F. (1649° C.). 
     
     
         36 . The method of  claim 16 , wherein the gas mixture comprises oxygen at a concentration from 0.1 vol % to 10 vol %, fuel gas at a concentration from 5 vol % to 70 vol %, and carbon dioxide at a concentration from 25 vol % to 90 vol %. 
     
     
         37 . The method of  claim 16 , wherein the gas mixture comprises oxygen at a concentration of greater than 10 vol % to 30 vol %. 
     
     
         38 . The method of  claim 16 , wherein the gas mixture has an oxygen to fuel molar ratio which is greater than stoichiometric and 1.5 to 20.