Removal of hydrogen

Abstract

The invention relates to a method for liquefying a hydrocarbon-rich fraction ( 1, 1′ ) which contains substantially methane, hydrogen and nitrogen. In the inventive method, before the liquefaction (V) of the hydrocarbon-rich fraction ( 1, 1′ ), the hydrogen ( 2 ) is removed (M) by permeation. This removal (M) of the hydrogen ( 2 ) by permeation is effected in a single-stage or multistage removal process.

1 . A method for liquefying a hydrocarbon-rich fraction ( 1 ,  1 ′) which contains substantially methane, hydrogen and nitrogen, said method comprising:
 removing hydrogen ( 2 ) by permeation (M) from said hydrocarbon-rich fraction ( 1 ,  1 ′) before liquefaction (V) of said hydrocarbon-rich fraction ( 1 ,  1 ′), and 
 subjecting said hydrocarbon-rich fraction ( 1 ,  1 ′) to liquefaction (V) to produce a liquefied hydrocarbon-rich fraction. 
 
     
     
         2 . The method according to  claim 1 , wherein said hydrogen ( 2 ) is removed by permeation (M) is removed by permeation in a single-stage removal process. 
     
     
         3 . The method according to  claim 1 , wherein said hydrogen ( 2 ) is removed by permeation (M) is removed by permeation in a multistage removal process. 
     
     
         4 . The method according to  claim 1 , wherein the removed hydrogen ( 2 ) is compressed (V 1 ). 
     
     
         5 . The method according to  claim 2 , wherein the removed hydrogen ( 2 ) is compressed (V 1 ). 
     
     
         6 . The method according to  claim 3 , wherein the removed hydrogen ( 2 ) is compressed (V 1 ). 
     
     
         7 . The method according to  claim 1 , wherein said liquefied hydrocarbon-rich fraction is temporarily stored, during this temporary storage a tank boil-off gas fraction ( 6 ) is produced, and said tank boil-off gas fraction ( 6 ) is compressed (V 2 ). 
     
     
         8 . The method according to  claim 2 , wherein said liquefied hydrocarbon-rich fraction is temporarily stored, during this temporary storage a tank boil-off gas fraction ( 6 ) is produced, and said tank boil-off gas fraction ( 6 ) is compressed (V 2 ). 
     
     
         9 . The method according to  claim 3 , wherein said liquefied hydrocarbon-rich fraction is temporarily stored, during this temporary storage a tank boil-off gas fraction ( 6 ) is produced, and said tank boil-off gas fraction ( 6 ) is compressed (V 2 ). 
     
     
         10 . The method according to  claim 4 , wherein said liquefied hydrocarbon-rich fraction is temporarily stored, during this temporary storage a tank boil-off gas fraction ( 6 ) is produced, and said tank boil-off gas fraction ( 6 ) is compressed (V 2 ). 
     
     
         11 . The method according to  claim 5 , wherein said liquefied hydrocarbon-rich fraction is temporarily stored, during this temporary storage a tank boil-off gas fraction ( 6 ) is produced, and said tank boil-off gas fraction ( 6 ) is compressed (V 2 ). 
     
     
         12 . The method according to  claim 6 , wherein said liquefied hydrocarbon-rich fraction is temporarily stored, during this temporary storage a tank boil-off gas fraction ( 6 ) is produced, and said tank boil-off gas fraction ( 6 ) is compressed (V 2 ). 
     
     
         13 . The method according to  claim 1 , wherein, during the process of liquefying the hydrocarbon-rich fraction, a nitrogen-rich fraction is removed, and said nitrogen-rich fraction ( 7 ) is compressed (V 3 ). 
     
     
         14 . The method according to  claim 4 , wherein the compressed hydrogen ( 2 ), and/or the compressed tank boil-off gas fraction ( 6 ), and/or the compressed nitrogen-rich fraction ( 7 ) are combined ( 8 ).