Method for integrating a co2 capture unit with the precooling section of a natural gas liquefaction plant

Abstract

A method of simultaneously liquefying CO2 and cooling natural gas, including providing a compressed CO2 loop, comprising a pressurized cooling stream, wherein a first compressed cooling stream and a second compressed cooling stream are produced by a CO2 compressor. Providing at least a portion of the first compressed cooling stream to a CO2 liquefaction system, wherein the first compressed cooling stream provides at least a portion of the refrigeration required by the CO2 liquefaction system. Providing at least a portion of the second compressed cooling stream to the pre-cooling system of a natural gas liquefaction system, wherein the second compressed cooling stream provides at least a portion of the refrigeration required by the natural gas pre-cooling.

What is claimed is: 
     
         1 . A method of simultaneously liquefying CO2 and cooling natural gas, comprising:
 providing a compressed CO2 loop, comprising a pressurized stream, wherein a first compressed stream and a second compressed stream are produced by a CO2 compressor,   providing at least a portion of the first compressed stream to a CO2 liquefaction system,   
       wherein the first compressed stream provides at least a portion of the refrigeration required by the CO2 liquefaction system,
 providing at least a portion of the second compressed stream to the pre-cooling system of a natural gas liquefaction system, 
 
       wherein the second compressed stream provides at least a portion of the refrigeration required by the natural gas pre-cooling. 
     
     
         2 . The method of  claim 1 , wherein the lowest pressure within the CO2 loop is greater than the triple point pressure of CO2. 
     
     
         3 . The method of  claim 1 , wherein the CO2 liquefaction system comprises at least one recycle stream that is introduced into the CO2 compressed CO2 loop. 
     
     
         4 . The method of  claim 1 , wherein the first compressed cooling stream and the second compressed cooling stream are at the same pressure. 
     
     
         5 . The method of  claim 1 , wherein the first compressed cooling stream and the second compressed cooling stream are at different pressures. 
     
     
         6 . A method of simultaneously producing a pressurized CO2 stream and cooling natural gas, comprising:
 providing a CO2 compressor system, comprising at least a first compressed stream and a second compressed stream,   
       wherein the first compressed stream and the second compressed stream are produced by a CO2 compressor,
 providing at least a portion of the first compressed stream to a downstream user, 
 providing at least a portion of the second compressed stream to the pre-cooling system of a natural gas liquefaction system, 
 
       wherein the second compressed stream provides at least a portion of the refrigeration required by the natural gas pre-cooling. 
     
     
         7 . The method of  claim 6 , wherein the lowest pressure within the CO2 loop is greater than the triple point pressure of CO2. 
     
     
         8 . The method of  claim 6 , wherein the downstream user is an enhanced oil recovery system. 
     
     
         9 . The method of  claim 6 , wherein the downstream user is a CO2 sequestration system.