Patent ID: 6407301
Filing Date: 2002-06-18
Classification: C10G

Abstract:
A process for preparing a feedstream to be charged to a steam cracking unit producing ethylene, which process comprises:a.) passing a process feed stream comprising C5 through C9 hydrocarbons including C5 through C9 normal paraffins into a first fractionation zone, and separating the hydrocarbons entering the first fractionation zone into a first process stream rich in C5 paraffins and a second process stream comprising C6 through C9 hydrocarbons; b.) passing the second process stream into an adsorption zone of an adsorptive separation zone and selectively retaining normal paraffins on an adsorbent located in the adsorption zone to yield a raffinate stream comprising non-normal C6 through C9 hydrocarbons; c.) passing the first process stream into a desorption zone in the adsorptive separation zone as at least part of a desorbent stream and removing normal paraffins from adsorbent present in the desorption zone to yield an extract stream comprising C6 through C9 normal paraffins and C5 paraffins; d.) separating the extract stream in a second fractionation zone into a third process stream comprising C5 paraffins and a fourth process stream comprising C6 through C9 normal paraffins; and, e.) passing the fourth process stream into a cracking zone and producing ethylene.