PROCESS FOR DENITROGENATING A LIQUIFIED HYDROCARBON MIXTURE CONTAINING MAINLY METHANE AND AT LEAST 2 NITROGEN BY MOLARITY

摘要

PCT No. PCT/FR92/00991 Sec. 371 Date Aug. 11, 1993 Sec. 102(e) Date Aug. 11, 1993 PCT Filed Oct. 22, 1992 PCT Pub. No. WO93/08436 PCT Pub. Date Apr. 29, 1993.The invention is a process for the denitrogization of a liquefied natural gas (LNG) comprising methane and at least 2 Mols. of nitrogen. The process is distinguished in that the LNG is introduced into the process as a liquid and is subject to an indirect heat exchange to cool the liquid and a further decompression before introduction into fractionation of column. A portion of the liquid flowing in the fractionation column is withdrawn and utilized to cool the LNG feedstock and is returned to the fractionation column at a level lower than the level from which it was withdrawn. The decompression of LNG feedstock comprises at least one dynamic decompression and at least one static decompression.