Integrated multicomponent refrigerant and air separation process for producing liquid oxygen

Abstract

A process for the production of a liquid oxygen stream and a liquid hydrocarbon-rich stream by the cryogenic rectification of an inlet air stream, including dividing the inlet air stream into a first portion, and a second portion. Cooling the first portion, and the second portion against a cooled multicomponent refrigerant circuit, thereby producing a first cooled portion, and a second cooled portion. Condensing the first cooled portion, thereby producing a condensed first portion, then introducing the condensed first portion into one or more distillation columns. Expanding the second cooled portion in a turbo-expander, thereby producing an expanded second portion, then introducing the expanded second portion within the one or more distillation columns. Producing within the one or more distillation columns at least a waste nitrogen stream, a nitrogen enriched stream, and an oxygen enriched stream.

What is claimed is: 
     
         1 . A process for the production of a liquid oxygen stream by the cryogenic rectification of an inlet air stream, comprising:
 cooling an inlet air stream and a gaseous hydrocarbon rich stream against a cooled multicomponent refrigerant circuit in at least one heat exchanger, thereby producing a cooled air stream and a liquefied hydrocarbon rich stream, and splitting the cooled air stream into at least a first cooled portion, and a second cooled portion, the multicomponent refrigerant circuit comprising:
 compressing a multicomponent refrigerant stream, thereby producing a pressurized multicomponent refrigerant stream, 
 cooling the pressurized multicomponent refrigerant stream, thereby producing a cooled multicomponent refrigerant stream, 
 expanding the cooled multicomponent refrigerant stream, thereby producing an expanded multicomponent refrigerant stream, and 
 warming the expanded multicomponent refrigerant stream by indirect heat exchange with the compressed multicomponent refrigerant stream and with the first portion, and the second portion, 
   condensing the first cooled portion, thereby producing a condensed first portion, then introducing at least a portion of the condensed first portion into one or more distillation columns,   expanding at least a portion of the second cooled portion in a turbo-expander, thereby producing an expanded second portion, then introducing at least a portion of the expanded second portion within the one or more distillation columns,   producing within the one or more distillation columns at a nitrogen enriched stream, and an oxygen enriched stream, and   withdrawing the oxygen enriched stream from the one or more distillation columns as a liquid oxygen stream.   
     
     
         2 . The process of  claim 1 , further comprising cooling the inlet aft stream and the gaseous hydrocarbon rich stream against the cooled multicomponent refrigerant circuit and a cold waste nitrogen stream. 
     
     
         3 . The process of  claim 1 , wherein the hydrocarbon rich stream is dried natural gas or primarily methane. 
     
     
         4 . The process of  claim 1 , wherein the hydrocarbon rich stream has a pressure greater than 20 bara. 
     
     
         5 . The process of  claim 1 , wherein at least one of the following streams is reduced in pressure by a dense fluid expander or a Joule Thompson valve: the condensed first portion, the expanded second portion, and the liquefied hydrocarbon rich stream. 
     
     
         6 . The process of  claim 1 , further comprising withdrawing an oxygen-argon containing stream from the distillation column, thereby producing at least an argon-lean stream and an argon-rich stream, wherein the argon-lean stream is reintroduced into the distillation column, and the argon-rich stream is withdrawn. 
     
     
         7 . The process of  claim 1 , wherein at least a portion of a nitrogen enriched stream is withdrawn from the one or more distillation columns as product liquid nitrogen. 
     
     
         8 . The process of  claim 1 , wherein the multicomponent refrigerant stream comprises one or more of the following components: nitrogen, argon, methane, ethane ethylene, propane, butane, pentane, a fluorocarbon. 
     
     
         9 . The process of  claim 1 , wherein the expanded multicomponent refrigerant stream has a first temperature, and the liquefied hydrocarbon-rich stream has a second temperature, wherein the first temperature is greater than the second temperature. 
     
     
         10 . The process of  claim 9 , wherein the first temperature is at least 3 C greater than the second temperature, 
     
     
         11 . The process of  claim 9 , wherein the hot collective flowrate is less than the cold collective flowrate in a section of the at least one heat exchanger which is at least 3 C colder than liquefied hydrocarbon-rich stream when withdrawn from the at least one heat exchanger. 
     
     
         12 . The process of  claim 1 , wherein the inlet air stream, gaseous hydrocarbon rich stream, multicomponent refrigerant streams exchange heat in a common heat exchanger. 
     
     
         13 . The process of  claim 12 , wherein no oxygen-rich stream having an oxygen composition greater than air enters the common heat exchanger.