System and Method for Integrated Carbon Dioxide Gas Separation from Combustion Gases

Abstract

An integrated fuel combustion system with gas separation (adsorptive, absorptive, membrane or other suitable gas separation) separates a portion of carbon dioxide from a combustion gas mixture and provides for recycle of separated carbon dioxide to the intake of a fuel combustor for combustion. A process for carbon dioxide separation and recycle includes: admitting combustion gas to a gas separation system; sorbing a portion of carbon dioxide; recovering a flue gas stream depleted in carbon dioxide for release or use; desorbing the carbon dioxide from the gas separation system; admitting an oxidant stream into the gas separation system and forming a mixed oxidant stream; and recycling a portion of the mixed oxidant stream to an inlet of the fuel combustor.

What is claimed is: 
     
         1 . An integrated gas separation process for separating at least a portion of a combustion gas stream from a fuel combustor of an integrated combustion gas separation system comprising said fuel combustor and a gas separation system, said combustion gas stream comprising at least carbon dioxide, and water components, the process comprising:
 (a) admitting a fuel stream to a fuel inlet and an oxidant stream to an oxidant inlet of said fuel combustor to produce said combustion gas stream;   (b) admitting said combustion gas stream into said gas separation system;   (c) sorbing at least a portion of said carbon dioxide component of said combustion gas stream within said gas separation system;   (d) recovering a flue gas stream depleted in carbon dioxide relative to said combustion gas stream from said gas separation system;   (e) desorbing at least a portion of said carbon dioxide component in said gas separation system;   (f) admitting at least periodically an oxidant stream into said gas separation system forming a mixed oxidant stream; and   (g) recovering at least periodically said mixed oxidant stream from said gas separation system and at least periodically admitting at least a portion of said mixed oxidant stream to said oxidant inlet of said fuel combustor,   wherein at least periodically substantially all of said desorbed carbon dioxide component is recovered in said mixed oxidant stream.   
     
     
         2 . The process of  claim 1 , further comprising at least periodically admitting substantially all of said desorbed carbon dioxide component in said mixed oxidant stream into said fuel combustor. 
     
     
         3 . The process of  claim 1 , further comprising recovering at least periodically a product stream enriched in carbon dioxide from said integrated combustion gas separation system. 
     
     
         4 . The process of  claim 3 , wherein a molar quantity of carbon dioxide in said product stream recovered from said integrated combustion gas separation system is preferably at a rate about equal to a molar quantity of carbon comprised in said fuel stream admitted into said fuel inlet of said fuel combustor. 
     
     
         5 . The process of  claim 3 , wherein recovering said product stream from said integrated gas separation system occurs at a location downstream of said fuel combustor and upstream of said gas separation system. 
     
     
         6 . The process of  claim 5 , wherein a molar quantity of carbon dioxide in said product stream recovered from said integrated combustion gas separation system is preferably at a rate about equal to a molar quantity of carbon comprised in said fuel stream admitted into said fuel inlet of said fuel combustor. 
     
     
         7 . The process of  claim 1 , wherein at least a portion of said oxidant stream admitted into said gas separator system is effective to desorb at least a portion of said carbon dioxide component. 
     
     
         8 . The process of  claim 7 , wherein said oxidant stream comprises an air stream. 
     
     
         9 . The process of  claim 7 , wherein said oxidant stream comprises an air stream supplemented with oxygen. 
     
     
         10 . The process of  claim 7 , wherein said oxidant stream comprises an oxidant stream containing less oxygen than ambient air. 
     
     
         11 . The process of  claim 1 , wherein at least a portion of a heat of sorption generated in step (c) is used in step (e) for desorbing at least a portion of said carbon dioxide component. 
     
     
         12 . The process of  claim 1 , wherein said integrated gas separation process comprises at least one of:
 an adsorptive gas separation process; and   an absorption gas separation process.   
     
     
         13 . The process of  claim 1 , wherein said oxidant stream comprises an air stream. 
     
     
         14 . The process of  claim 1 , wherein said oxidant stream comprises an air stream supplemented with oxygen. 
     
     
         15 . The process of  claim 1 , wherein said oxidant stream comprises an oxidant stream containing less oxygen than ambient air. 
     
     
         16 . An integrated combustion gas separation system for separating at least a portion of a combustion gas stream, said combustion gas stream comprising at least carbon dioxide and water components, the system comprising:
 (a) a fuel combustor comprising a fuel inlet, an oxidant inlet, and an exhaust outlet, that during operation produces said combustion gas stream;   (b) a gas separation system comprising a combustion gas inlet, an oxidant inlet, a flue gas outlet, a mixed gas outlet, and at least one sorbent contactor having at least one sorbent material, operable for separating said carbon dioxide component from said combustion gas stream by sorption of at least a portion of said carbon dioxide component on at least one said sorbent material;   (c) a combustion gas conduit fluidly connected to said exhaust outlet of said fuel combustor and said combustion gas inlet of said gas separation system, and   (d) a mixed gas conduit fluidly connected to said mixed gas outlet of said gas separation system and said oxidant inlet of said fuel combustor for recovering substantially all of a desorbed portion of said carbon dioxide component from said gas separation system.   
     
     
         17 . The integrated combustion gas separation system of  claim 16 , wherein said gas separation system comprises at least one of:
 an adsorptive gas separation system; and   an absorption gas separation system.   
     
     
         18 . The integrated combustion gas separation system of  claim 16 , further comprising an enriched carbon dioxide conduit fluidly connected to said combustion gas conduit for recovering a product stream enriched in said carbon dioxide component. 
     
     
         19 . The integrated combustion gas separation system of  claim 18 , wherein said gas separation system comprises at least one of:
 an adsorptive gas separation system; and   an absorption gas separation system.