Process for introducing a multicomponent liquid feed stream into a distillation column operating at lower pressure

A process for introducing a multicomponent liquid feed stream (10) at pressure (P2) into a distillation column (C1) operating at lower pressure (P1). The process comprises removing a split stream (12) from the feed stream (10), reducing its pressure (V1) and using the resulting stream (13) to subcool (H1) the feed stream (OV) remainder of the feed stream (10). After being subcooled, the remainder of the feed stream (10) is also reduced in pressure (V2) and both streams (14,16) are fed to different stages of the distillation column (C1). An important embodiment of the present invention is within a conventional double column air separation cycle where the multicomponent liquid stream is the crude liquid oxygen stream from the bottom of the high pressure column which must be reduced in pressure prior to its introduction into the low pressure column.