Regasification Plant

Abstract

Methods and system are provided for regasifying liquefied natural gas (LNG). An exemplary method disclosed includes flowing at least a portion of an LNG stream through an air separation unit (ASU) to form at least a portion of a natural gas (NG) stream. Heat is removed from an airflow in the ASU to separate an oxygen stream from the airflow. The oxygen stream and a fuel stream are combusted in a power plant.

What is claimed is: 
     
         1 . A method for regasifying liquefied natural gas (LNG), comprising:
 flowing at least a portion of an LNG stream through an air separation unit (ASU) to form at least a portion of a natural gas (NG) stream;   removing heat from an airflow in the ASU to separate an oxygen stream from the airflow; and   combusting the oxygen stream and a fuel stream in a power plant.   
     
     
         2 . The method of  claim 1 , comprising:
 flowing a portion of the LNG stream through a gaseous carbon dioxide (CO 2 ) chiller to form a portion of the NG stream; and   forming a liquefied CO 2  stream in the CO 2  chiller.   
     
     
         3 . The method of  claim 1 , comprising:
 flowing a portion of the LNG stream through a nitrogen (N 2 ) chiller to form a portion of the NG stream; and   forming a liquefied N 2  stream in the N 2  chiller.   
     
     
         4 . The method of  claim 1 , comprising providing the NG stream to a market. 
     
     
         5 . The method of  claim 1 , comprising:
 generating electrical power in the power plant; and   providing the electrical power to a market.   
     
     
         6 . The method of  claim 2 , comprising providing the liquefied CO 2  stream to a market. 
     
     
         7 . The method of  claim 1 , comprising injecting the CO 2  stream into a subterranean formation. 
     
     
         8 . The method of  claim 1 , comprising injecting the CO 2  stream proximate to a seabed. 
     
     
         9 . The method of  claim 1 , comprising venting a nitrogen stream to the atmosphere. 
     
     
         10 . The method of  claim 1 , comprising chilling the oxygen stream with LNG prior to the power plant. 
     
     
         11 . A system for regasifying liquefied natural gas, comprising:
 an air separation unit configured to utilize cold from a portion of a stream of liquefied natural gas (LNG) to cryogenically distill an air stream to produce an oxygen stream and a nitrogen stream, forming a natural gas (NG) stream; and   a power plant configured to combust the oxygen stream with a fuel stream.   
     
     
         12 . The system of  claim 11 , comprising a cold box configured to condense liquid CO 2  from an exhaust stream of the power plant by transferring heat to a portion of the stream of LNG. 
     
     
         13 . The system of  claim 11 , wherein the power plant comprises a combined cycle power plant, comprising a gas turbine generator and a heat recovery steam generator. 
     
     
         14 . The system of  claim 11 , further comprising an inlet air cooler on a gas turbine engine configured to transfer heat from an oxygen stream to an LNG stream. 
     
     
         15 . The system of  claim 11 , comprising an electrical generator. 
     
     
         16 . The system of  claim 11 , wherein the power plant comprises a steam generator, a steam turbine generator, a steam condenser, and a recirculation pump. 
     
     
         17 . A method for cryogenically distilling a gas mixture, comprising:
 compressing the gas mixture;   flowing the gas mixture through a chiller to cool the gas mixture and liquefy at least a portion of the gas mixture;   flowing a liquefied natural gas through the chiller from the gas mixture to remove heat from the gas mixture;   flowing the cooled gas mixture into a cryogenic separation column;   removing a product gas mixture from an upper section of the cryogenic separation column; and   removing a product liquid from a lower section of the cryogenic separation column.   
     
     
         18 . The method of  claim 17 , comprising purifying the gas mixture after compression to remove carbon dioxide and water vapor. 
     
     
         19 . The method of  claim 17 , comprising liquefying the product gas. 
     
     
         20 . The method of  claim 17 , comprising regasifying the product liquid.