Carbon dioxide capture systems and methods

Abstract

A carbon dioxide separation system includes a compressor for receiving an exhaust gas comprising CO 2 and generate a compressed exhaust gas and a separator configured to receive the compressed exhaust gas and generate a CO 2 lean stream. The separator includes a first flow path for receiving the compressed exhaust gas, a second flow path for directing a sweep fluid therethrough, and a material with selective permeability of carbon dioxide for separating the first and the second flow paths and for promoting carbon dioxide transport therebetween. The system further includes an expander coupled to the compressor for receiving and expanding the CO 2 lean stream to generate power and an expanded CO 2 lean stream.

1 . A carbon dioxide separation system comprising:
 a compressor for receiving an exhaust gas comprising CO 2  and generate a compressed exhaust gas;   a separator configured to receive said compressed exhaust gas and generate a CO 2  lean stream, said separator comprising;   a first flow path for receiving said compressed exhaust gas;   a second flow path for directing a sweep fluid therethrough; and   a material with selective permeability of carbon dioxide for separating said first and said second flow paths and for promoting carbon dioxide transport therebetween; and   an expander coupled to said compressor for receiving and expanding said CO 2  lean stream to generate power and an expanded CO 2  lean stream.   
     
     
         2 . The carbon dioxide separation system according to  claim 1 , wherein said sweep fluid is at a sub-atmospheric pressure. 
     
     
         3 . The carbon dioxide separation system according to  claim 1 , wherein said exhaust gas is generated from one or more of a coal-fired power plant or a natural gas combined cycle power plant or an industrial process generating a CO 2  rich flue gas. 
     
     
         4 . The carbon dioxide separation system according to  claim 3 , wherein a portion of said exhaust gas is recycled back into said coal-fired power plant or natural gas combined cycle power plant. 
     
     
         5 . The carbon dioxide separation system according to  claim 1  further comprising a heat exchanger configured to receive said compressed exhaust gas and CO 2  lean stream to generate a cold compressed exhaust gas. 
     
     
         6 . The carbon dioxide separation system according to  claim 1  further comprising a pre-cooler to cool down said compressed exhaust gas. 
     
     
         7 . The carbon dioxide separation system according to  claim 1 , wherein said exhaust gas comprises at about 3% to about 15% CO 2  by volume. 
     
     
         8 . The carbon dioxide separation system according to  claim 1  further comprising a particle removal unit configured to remove particles from said exhaust gas. 
     
     
         9 . The carbon dioxide separation system according to  claim 1 , wherein said separator is a membrane separator configured to generate a permeate stream comprising CO 2 . 
     
     
         10 . The carbon dioxide separation system according to  claim 9 , wherein said membrane separator is selected from a group consisting of mixed matrix membranes, facilitated transport membranes, hollow fiber membranes, spiral wound membranes, ionic liquid membranes and polymerized ionic liquid membranes. 
     
     
         11 . A carbon dioxide separation system in accordance with  claim 1 , wherein said exhaust gas is in the temperature range between about 150° C. to about 700° C. 
     
     
         12 . A carbon dioxide separation system in accordance with  claim 1 , wherein said sweep fluid is a condensable fluid. 
     
     
         13 . A carbon dioxide separation system in accordance with  claim 1 , wherein said sweep fluid is steam. 
     
     
         14 . A carbon dioxide separation system in accordance with  claim 1 , wherein said sweep fluid is an organic compound. 
     
     
         15 . The carbon dioxide separation system in accordance with  claim 1 , wherein said sweep fluid is selected from the group consisting of refrigerants; alcohols; fluorinated and non-fluorinated hydrocarbons, ketones, esters, and ethers; siloxanes and combinations thereof. 
     
     
         16 . The carbon dioxide separation system in accordance with  claim 1 , wherein said sweep fluid is at a pressure of about 0.1 to about 0.3 bar. 
     
     
         17 . The carbon dioxide separation system in accordance with  claim 1  further comprising a post purification system and a compressing system. 
     
     
         18 . The carbon dioxide separation system in accordance with  claim 17 , wherein said compressing system comprises a compressor with at least one stage to compressed said permeate stream to produce CO 2  rich stream at high pressure. 
     
     
         19 . The carbon dioxide separation system in accordance with  claim 1 , wherein said exhaust gas is produced from at least one of a gas turbine, a furnace, a thermal oxidizer, metal processing systems, or an industrial process. 
     
     
         20 . A carbon dioxide separation system comprising:
 a compressor for receiving an exhaust gas comprising CO 2  and generate a compressed exhaust gas;   a membrane separator configured to receive said compressed exhaust gas and generate a CO 2  lean stream, said membrane separator comprising;   a first flow path for receiving said compressed exhaust gas;   a second flow path for directing a sweep fluid therethrough wherein said sweep fluid is at a sub-atmospheric pressure; and   a material with selective permeability of carbon dioxide for separating said first and said second flow paths and for promoting carbon dioxide transport therebetween; and   an expander coupled to said compressor for receiving and expanding said CO 2  lean stream to generate power and an expanded CO 2  lean stream.   
     
     
         21 . A carbon dioxide separation system in accordance with  claim 20 , wherein said sweep fluid is steam. 
     
     
         22 . A carbon dioxide separation system comprising:
 a compressor for receiving an exhaust gas comprising CO 2  and generate a compressed exhaust gas;   a facilitated transport membrane separator configured to receive said compressed exhaust gas and generate a CO 2  lean stream, said facilitated transport membrane separator comprising;   a first flow path for receiving said compressed exhaust gas;   a second flow path for directing a sweep fluid therethrough, wherein said sweep fluid is at a sub-atmospheric pressure; and   a material with selective permeability of carbon dioxide for separating said first and said second flow paths and for promoting carbon dioxide transport therebetween and   an expander coupled to said compressor for receiving and expanding said CO 2  lean stream to generate power and an expanded CO 2  lean stream.   
     
     
         23 . An exhaust gas treatment system comprising:
 a compressor for receiving an exhaust gas comprising CO 2  and generate a compressed exhaust gas, wherein said exhaust gas is generated from a coal gasification plant or a natural gas combined cycle power plant;   a membrane separator configured to receive said compressed exhaust gas and generate a CO 2  lean stream, said membrane separator comprising;   a first flow path for receiving said compressed exhaust gas;   a second flow path for directing a sweep fluid therethrough, wherein said sweep fluid is at a sub-atmospheric pressure; and   a material with selective permeability of carbon dioxide for separating said first and said second flow paths and for promoting carbon dioxide transport therebetween;   an expander coupled to said compressor for receiving and expanding said CO 2  lean stream to generate power and an expanded CO 2  lean stream; and   a post purification system and a compressing system to generate a high pressure CO 2  rich stream.   
     
     
         24 . A method for separating carbon dioxide comprising:
 compressing an exhaust gas comprising CO 2  and generating a compressed exhaust gas;   receiving said compressed exhaust gas in a separator and generating a CO 2  lean stream, said separator comprising;   a first flow path for receiving said compressed exhaust gas;   a second flow path for directing a sweep fluid therethrough wherein said sweep fluid is at a sub-atmospheric pressure; and   a material with selective permeability of carbon dioxide for separating said first and said second flow paths and for promoting carbon dioxide transport therebetween; and   expanding said CO 2  lean stream to generate power and an expanded CO 2  lean stream.   
     
     
         25 . The method of  claim 25 , wherein said separator is a membrane separator.