Expander and method for co2 separation

Abstract

In one aspect an expander for separating carbon dioxide (CO 2 ) from a gas stream is presented. The expander includes (a) a housing; (b) at least one rotating component disposed within the housing; (c) at least one inlet disposed in the housing, wherein the inlet is configured to receive the gas stream;(d) at least one first outlet disposed in the housing, wherein the first outlet is configured to discharge a CO 2 rich stream; and (e) at least one second outlet disposed in the housing, wherein the second outlet is configured to discharge a CO 2 lean stream. The expander is configured to cool the gas stream such that a portion of CO 2 in the gas stream forms one or both of solid CO 2 and liquid CO 2 . The expander is further configured to separate at least a portion of one or both of solid CO 2 and liquid CO 2 from the gas stream to form the CO 2 rich stream and the CO 2 lean stream. System and method for separating carbon dioxide (CO 2 ) from a gas stream are also presented

What is claimed is: 
     
         1 . An expander for separating carbon dioxide (CO 2 ) from a gas stream, comprising:
 (a) a housing;   (b) at least one rotating component disposed within the housing;   (c) at least one inlet disposed in the housing, wherein the inlet is configured to receive the gas stream;   (d) at least one first outlet disposed in the housing, wherein the first outlet is configured to discharge a CO 2  rich stream; and   (e) at least one second outlet disposed in the housing, wherein the second outlet is configured to discharge a CO 2  lean stream;
 wherein the expander is configured to cool the gas stream such that a portion of CO 2  in the gas stream forms one or both of solid CO 2  and liquid CO 2 , and 
 wherein the expander is further configured to separate at least a portion of one or both of solid CO 2  and liquid CO 2  from the gas stream to form the CO 2  rich stream and the CO 2  lean stream. 
   
     
     
         2 . The expander as defined in  claim 1 , wherein the expander is configured to cool the gas stream such that a portion of CO 2  in the gas stream primarily forms solid CO 2 , and
 wherein the expander is further configured to separate the solid CO 2  from the gas stream to form a solid CO 2  rich stream.   
     
     
         3 . The expander as defined in  claim 1 , wherein the housing comprises one or more separation channels in fluid communication with the first outlet and configured to separate the CO 2  rich stream from the gas stream. 
     
     
         4 . The expander as defined in  claim 1 , wherein the expander is configured to separate at least about 50 mass percent of CO 2  present in the gas stream. 
     
     
         5 . The expander as defined in  claim 1 , wherein the CO 2  lean stream is substantially free of CO 2 . 
     
     
         6 . The expander as defined in  claim 2 , wherein at least one component of the expander further comprises a coating configured to preclude adhesion of solid CO 2  to a surface of the expander component. 
     
     
         7 . The expander as defined in  claim 2 , wherein the expander further comprises at least one heated component configured to preclude adhesion of solid CO 2  to a surface of the expander component. 
     
     
         8 . The expander as defined in  claim 1 , further comprising at least one separator in fluid communication with the second outlet of the expander, wherein the at least one separator is configured to separate a portion of CO 2  in the CO 2  lean stream to form a supplementary CO 2  rich stream. 
     
     
         9 . The expander as defined in  claim 1 , wherein the first outlet is disposed in the housing at a location upstream of the rotating component and the second outlet is disposed in the housing at a location downstream of the rotating component. 
     
     
         10 . A system for separating carbon dioxide (CO 2 ) from a gas stream, comprising:
 (i) at least one compression stage and at least one cooling stage configured to compress and cool a gas stream;   (ii) at least one expansion stage comprising at least one expander in fluid communication with the cooling stage or the compression stage, the expander comprising:
 (a) a housing; 
 (b) at least one rotating component disposed within the housing; 
 (c) at least one inlet disposed in the housing, wherein the inlet is configured to receive the gas stream; 
 (d) at least one first outlet disposed in the housing, wherein the first outlet is configured to discharge a CO 2  rich stream; and 
 (e) at least one second outlet disposed in the housing, wherein the second outlet is configured to discharge a CO 2  lean stream; 
 wherein the expander is configured to cool the gas stream such that a portion of CO 2  in the gas stream forms one or both of solid CO 2  and liquid CO 2 , and 
 wherein the expander is further configured to separate at least a portion of one or both of solid CO 2  and liquid CO 2  from the gas stream to form the CO 2  rich stream and the CO 2  lean stream. 
   
     
     
         11 . The system as defined in  claim 10 , wherein the expander is configured to cool the gas stream such that a portion of CO 2  in the gas stream primarily forms solid CO 2 , and
 wherein the expander is further configured to separate the solid CO 2  from the gas stream to form a solid CO 2  rich stream.   
     
     
         12 . The system as defined in  claim 11 , wherein at least one component of the expander further comprises a coating configured to preclude adhesion of solid CO 2  to a surface of the expander component. 
     
     
         13 . The system as defined in  claim 11 , wherein the expander further comprises at least one heated component configured to preclude adhesion of solid CO 2  to a surface of the expander component. 
     
     
         14 . The system as defined in  claim 10 , further comprising at least one separator in fluid communication with the second outlet of the expander,
 wherein the at least one separator is configured to separate a portion of CO 2  in the CO 2  lean stream to form a supplementary CO 2  rich stream.   
     
     
         15 . A method of separating carbon dioxide (CO 2 ) from a gas stream, comprising:
 (i) providing an expander, comprising:
 (a) a housing; 
 (b) at least one rotating component disposed within the housing 
 (c) at least one inlet disposed in the housing, wherein the inlet is configured to receive the gas stream; 
 (d) at least one first outlet disposed in the housing, wherein the first outlet is configured to discharge a CO 2  rich stream; and 
 (e) at least one second outlet disposed in the housing, wherein the second outlet is configured to discharge a CO 2  lean stream; 
   (ii) cooling the gas stream in the expander such that a portion of CO 2  in the gas stream forms one or both of solid CO 2  and liquid CO 2 ; and   (iii) separating at least a portion of one or both of solid CO 2  and liquid CO 2  from the gas stream in the expander to form the CO 2  rich stream and the CO 2  lean stream.   
     
     
         16 . The method as defined in  claim 15 , wherein step (i) comprises cooling the gas stream in the expander to primarily form solid CO 2  and step (ii) comprises separating the solid CO 2  from the gas stream to form a solid CO 2  rich stream. 
     
     
         17 . The method as defined in  claim 15 , wherein at least about  50  volume percent of CO 2  present in the gas stream is separated in step (ii). 
     
     
         18 . The method as defined in  claim 15 , wherein the CO 2  lean stream is substantially free of CO 2 . 
     
     
         19 . The method as defined in  claim 15 , wherein step (ii) comprises separating at least a portion of one or both of solid CO 2  and liquid CO 2  from the gas stream in the expander through one or more separation channels. 
     
     
         20 . The method as defined in  claim 16 , wherein at least one component of the expander further comprises a coating configured to preclude adhesion of solid CO 2  to a surface of the expander component. 
     
     
         21 . The method as defined in  claim 16 , further comprising heating at least one component of the expander to preclude adhesion of solid CO 2  to a surface of the expander component.