Olefin separation process

Claim 1

In a process for the separation of olefins from a hydrocarbon feed mixture comprising olefins from a hydrocarbon feed mixture comprising olefins and saturates, which process comprises the steps of: a. contacting said feed mixture with a bed of zeolite adsorbent at adsorption conditions to effect the selective adsorption of said olefins by said adsorbent; b. withdrawing from said bed of adsorbent a raffinate stream comprising less selectively adsorbed saturates; c. contacting the adsorbent bed with a desorbent material at desorption conditions to effect desorption of said olefins from said adsorbent; and, d. withdrawing a stream containing olefins and desorbent material from said bed of adsorbent; THE IMPROVEMENT WHICH COMPRISES employing a zeolite adsorbent prepared by the steps of: i. contacting a precursor mass comprising an X structured zeolite, and an amorphous binder selected from the group consisting of silica, alumina, and silica-alumina, and having a Na 2 O/Al 2 O 3 ratio of less than about 0.7 with an aqueous sodium hydroxide solution at ion exchange conditions for 0.5 to 5 hours to increase the sodium cation content to a Na 2 O/Al 2 O 3 ratio of greater than about 0.7 and to remove from about 1 to about 15 wt. % of SiO 2 and Al 2 O 3 from the precursor mass; ii. washing said mass with water maintained at a pH within the range of 7 to 10 to remove therefrom excess sodium hydroxide; and, iii. at least partially dehydrating said meass at dehydrating conditions.