Patent ID: 7148392

Claim:
A process for selectively separating 1-butene from a C 4 feed stream comprising at least 1-butene, trans-2-butene and cis-2-butene, the process comprising the steps of: (a) passing the feed stream through a first bed of an adsorbent comprising a crystalline microporous material to form a substantially trans-2-butene-free effluent stream; and (b) passing the effluent stream through a second bed of an adsorbent comprising a crystalline microporous material to form a substantially 1-butene-free effluent stream, whereby the 1-butene is separated from the feed stream, wherein the crystalline microporous materials of steps (a) and (b) comprise different cation-free non-acidic crystalline microporous materials, wherein the window size of the cation-free non-acidic crystalline microporous material of step (b) is larger than the window size of the cation-free non-acidic crystalline microporous material of step (a).