Method for liquefying a hydrocarbon-rich stream

Abstract

A method for liquefying a hydrocarbon-rich stream, in particular a natural gas stream, is disclosed. A liquefaction of the hydrocarbon-rich stream takes place countercurrent to a refrigerant mixture cycle cascade consisting of two or three refrigerant mixture cycles. No additional process steps are involved in the heat exchange between the hydrocarbon-rich stream which is to be precooled and the refrigerant mixture of the first refrigerant mixture cycle.

1 - 10 . (canceled) 
     
     
         11 . A method for liquefying a hydrocarbon-rich stream, in particular a natural gas stream, wherein a liquefaction of the hydrocarbon-rich stream takes place countercurrent to a refrigerant mixture cycle cascade consisting of two refrigerant mixture cycles and wherein a first refrigerant mixture cycle is used for precooling and a second refrigerant mixture cycle is used for liquefaction and supercooling of the hydrocarbon-rich stream to be liquefied, wherein no additional process steps are involved in a heat exchange between the hydrocarbon-rich stream which is to be precooled and the refrigerant mixture of the first refrigerant mixture cycle. 
     
     
         12 . A method for liquefying a hydrocarbon-rich stream, in particular a natural gas stream, wherein a liquefaction of the hydrocarbon-rich stream takes place countercurrent to a refrigerant mixture cycle cascade consisting of three refrigerant mixture cycles and wherein a first of the three refrigerant mixture cycles is used for precooling, a second refrigerant mixture cycle for an actual liquefaction and a third refrigerant mixture cycle for supercooling the liquefied hydrocarbon-rich stream, wherein no additional process steps are involved in a heat exchange between the hydrocarbon-rich stream which is to be precooled and the refrigerant mixture of the first refrigerant mixture cycle. 
     
     
         13 . The method according to  claim 11 , wherein at least one partial stream of the refrigerant mixture of the second refrigerant mixture cycle is used for the precooling of the hydrocarbon-rich stream, wherein the partial stream from the refrigerant mixture of the second refrigerant mixture cycle is involved in the heat exchange between the hydrocarbon-rich stream and the refrigerant mixture of the first refrigerant mixture cycle. 
     
     
         14 . The method according to  claim 11 , wherein the heat exchange between the hydrocarbon-rich stream to be precooled and the refrigerant mixture of the first refrigerant mixture cycle is implemented in at least one straight-tube heat exchanger. 
     
     
         15 . The method according to  claim 14 , wherein the heat exchanger is a plate heat exchanger or a coil-type heat exchanger. 
     
     
         16 . The method according to  claim 11 , wherein no additional process streams are involved in a heat exchange countercurrent to itself of the refrigerant mixture of the first refrigerant mixture cycle. 
     
     
         17 . The method according to  claim 16 , wherein the exchange of heat of the refrigerant mixture of the first refrigerant mixture cycle countercurrent to itself is implemented in at least one straight tube heat exchanger. 
     
     
         18 . The method according to  claim 17 , wherein the heat exchanger is a plate heat exchanger or a coil-type heat exchanger. 
     
     
         19 . The method according to  claim 11 , wherein a cooling of the refrigerant mixture of the second refrigerant mixture cycle takes place countercurrent to refrigerant mixture partial streams of the first refrigerant mixture cycle in a separate heat exchanger. 
     
     
         20 . The method according to  claim 19 , wherein the separate heat exchanger is a plate heat exchanger or a coil-type heat exchanger. 
     
     
         21 . The method according to  claim 12 , wherein a cooling of the refrigerant mixture of the third refrigerant mixture cycle takes place countercurrent to refrigerant mixture partial streams of the first refrigerant mixture cycle in a separate heat exchanger. 
     
     
         22 . The method according to  claim 21 , wherein the separate heat exchanger is a plate heat exchanger or a coil-type heat exchanger. 
     
     
         23 . The method according to  claim 12 , wherein a cooling of the refrigerant mixture of the second refrigerant mixture cycle takes place countercurrent to refrigerant mixture partial streams of the first refrigerant mixture cycle and a cooling of the refrigerant mixture of the third refrigerant mixture cycle takes place countercurrent to refrigerant mixture partial streams of the first refrigerant mixture cycle in dual-stream heat exchangers. 
     
     
         24 . The method according to  claim 23 , wherein the dual-stream heat exchangers are plate heat exchangers. 
     
     
         25 . A method for liquefying a hydrocarbon-rich stream, comprising the steps of:
 liquefaction of the hydrocarbon-rich stream countercurrent to a refrigerant mixture cycle cascade consisting of two refrigerant mixture cycles, wherein a first refrigerant mixture cycle is used for precooling and a second refrigerant mixture cycle is used for liquefaction and supercooling of the hydrocarbon-rich stream to be liquefied, wherein no additional process steps are involved in a heat exchange between the hydrocarbon-rich stream which is to be precooled and the refrigerant mixture of the first refrigerant mixture cycle.   
     
     
         26 . A method for liquefying a hydrocarbon-rich stream, comprising the steps of:
 liquefaction of the hydrocarbon-rich stream countercurrent to a refrigerant mixture cycle cascade consisting of at least two refrigerant mixture cycles;   wherein a first refrigerant mixture cycle precools the hydrocarbon-rich stream and wherein a second refrigerant mixture cycle liquefies and supercools the hydrocarbon-rich stream;   and wherein no additional process steps are involved in a heat exchange between the hydrocarbon-rich stream and the first refrigerant mixture cycle in the precooling step.   
     
     
         27 . The method according to  claim 26 , wherein the liquefaction of the hydrocarbon-rich stream countercurrent to the refrigerant mixture cycle cascade includes a third refrigerant mixture cycle;
 wherein the second refrigerant mixture cycle liquefies the hydrocarbon-rich stream and wherein the third refrigerant mixture cycle supercools the liquefied hydrocarbon-rich stream.