Method and apparatus for producing liquid carbon dioxide

Abstract

The invention relates to an apparatus for producing carbon dioxide-rich liquid, which includes a separation unit including a column for physically washing with a solvent and means for cooling a fluid of the separation unit, and a unit for compressing and liquefying a carbon dioxide-rich gas derived from the separation unit, including means for cooling the gas upstream and/or downstream from the compression operation, a single refrigerating cycle using carbon dioxide as the refrigerant, which is suitable for providing frigories to the means for cooling the fluid of the separation unit and to the means for cooling the gas upstream and/or downstream from the compression operation, and means for sending a portion of the liquid from the liquefaction unit to the refrigerating cycle.

1 - 10 . (canceled) 
     
     
         11 . A method for producing a carbon dioxide-rich liquid as end product, comprising;
 i) separating a feed gas comprising carbon dioxide by physical washing with a solvent at a temperature below 0° C.,   ii) cooling the solvent required for the physical washing of step i),   iii) producing a carbon dioxide-rich gas by separation according to step i), said gas is compressed and liquefied,   iv) cooling the carbon dioxide-rich gas upstream and/or downstream of the compression operation of step iii) and,   v) supplying the refrigeration for the cooling operation of step iv) and for a cooling operation required in step I) with a single refrigeration cycle, using carbon dioxide as refrigerant, at least part of the carbon dioxide used as refrigerant issuing from the liquefaction operation of step iii).   
     
     
         12 . The method of  claim 11 , further comprising cooling the solvent upstream of the washing operation with said refrigeration cycle. 
     
     
         13 . The method of  claim 11 , wherein the solvent is methanol. 
     
     
         14 . The method of  claim 11 , wherein the carbon dioxide-rich gas is liquefied after the compression operation of step iii). 
     
     
         15 . The method of  claim 11 , wherein the carbon dioxide-rich gas is cooled upstream of the compression operation of step iii) by means of the refrigeration cycle. 
     
     
         16 . The method of  claim 11 , wherein the carbon dioxide-rich gas is cooled downstream of the compression operation of step iii) by means of the refrigeration cycle. 
     
     
         17 . An apparatus for producing a carbon dioxide-rich liquid as end product, comprising
 i) a separation unit comprising a column for physical washing with a solvent and means for cooling a fluid of the separation unit,   ii) a unit for compressing and liquefying a carbon dioxide-rich gas derived from the separation unit, the compression and liquefaction unit comprising means for cooling the carbon dioxide-rich gas upstream and/or downstream of the compression operation,   iii) a single refrigeration cycle using carbon dioxide as refrigerant, being suitable for supplying refrigeration to the means for cooling the fluid of the separation unit and to the means for cooling the carbon dioxide-rich gas upstream and/or downstream of the compression operation and   iv) means for sending part of the carbon dioxide-rich liquid from the separation and liquefaction unit to the refrigeration cycle.   
     
     
         18 . The apparatus of  claim 17 , wherein the refrigeration cycle is suitable for supplying refrigeration upstream of the compression of the carbon dioxide-rich gas. 
     
     
         19 . The apparatus of  claim 17  the compression of the carbon dioxide-rich gas. 
     
     
         20 . The apparatus of  claim 17 , comprising a means for cooling the solvent upstream of the washing operation by means of the refrigeration cycle.