Carbon Dioxide Recovery Method Using Cryo-Condensation

Abstract

The present invention relates to a method of capturing carbon dioxide in a fluid comprising at least one compound more volatile than carbon dioxide CO2, for example methane CH4, oxygen O2, argon Ar, nitrogen N2, carbon monoxide CO, helium He and/or hydrogen H2.

1 - 10 . (canceled) 
     
     
         11 . A method for producing at least one CO2-lean gas and one or more CO2-rich primary fluids from a process fluid containing CO2 and at least one compound more volatile than CO2, comprising:
 a) a first cooling of said process fluid by exchange of heat with no change in state;   b) a second cooling of at least part of said process fluid cooled in step a) so as to obtain at least one solid containing predominantly CO2 and at least said CO2-lean gas; and   c) a step comprising liquefaction of at least part of said solid and making it possible to obtain said one or more CO2-rich primary fluids;   
       wherein at least part of said first cooling performed in step a) is obtained by heating up at least part of said one or more CO2-rich primary fluids. 
     
     
         12 . The method of  claim 11 , wherein step b) takes place at a total pressure such that the partial pressure of the CO2 contained in said process fluid is below or equal to that of the triple point of CO2, said total pressure preferably being close to atmospheric pressure, and in that said step c) occurs at a total pressure above that of the triple point of CO2, preferably close thereto. 
     
     
         13 . The method of  claim 12 , wherein step c) comprises a liquefaction obtained by introducing at least part of said solid into a liquid bath containing predominantly CO2 and extracting from said liquid bath at least one CO2-rich primary liquid. 
     
     
         14 . The method of  claim 13 , wherein said liquid bath is heated by one or more of the following methods:
 by exchange of heat with a fluid without said fluid mixing with said liquid bath;   by exchange of heat with a CO2-rich secondary fluid without said secondary fluid mixing with said liquid bath, said CO2-rich secondary fluid used to heat said liquid bath circulating in a closed loop and being heated by exchange of heat with said process fluid; and/or   by introducing and mixing into said liquid bath a CO2-rich secondary fluid.   
     
     
         15 . The method of  claim 13 , wherein at least part of said CO2-rich primary fluids is obtained from said CO2-rich primary liquid by one or more of the following methods:
 expansion to produce a fluid at a pressure higher than that of the triple point of CO2; and/or   compression to one or more pressure levels higher than that of the triple point for CO2.   
     
     
         16 . The method of  claim 11 , wherein at least part of said CO2-rich primary fluids comprises a liquid phase and in that said heating-up of at least a part of said CO2-rich primary fluids by exchange of heat with said process fluid vaporizes at least part of this liquid phase. 
     
     
         17 . The method of  claim 11 , wherein at least one of said CO2-rich primary fluids remains in the liquid or pseudo-liquid state during said heating-up of at least part of said CO2-rich primary fluids by exchange of heat with said process fluid. 
     
     
         18 . The method of  claim 11 , wherein at least part of said first cooling performed in step a) is obtained by exchange of heat with an intermediate fluid that has exchanged cold with at least part of said one or more CO2-rich primary fluids. 
     
     
         19 . The method of  claim 11 , wherein at least part of said CO2-rich primary fluids, after heating-up by exchange of heat with said process fluid, is compressed to one or more pressure levels higher than the supercritical pressure for CO2. 
     
     
         20 . The method of  claim 11 , wherein said method is applied to industrial flue gases with a view to capturing CO2.