Patent ID: 6858766

Claim:
A process for selectively hydrogenating C 2 -C 10 acetylenes and diolefins in an olefin production plant comprising the steps of, in sequence (1) passing an olefin plant feed stream through a mixed phase hydrogenation reactor [ 24 ] to mixed phase-hydrogenate at least a portion of the C 2 -C 10 acetylenes and diolefins; (2) passing the effluent from the mixed phase hydrogenation reactor [ 24 ] through a front depropanizer [ 27 ] to separate into a vapor stream rich in C 3 and lighter components and a liquid stream rich in C 4 and heavier components; or passing the effluent from the mixed phase hydrogenation reactor [ 24 ] through a front deethanizer [ 27 ] to separate into a vapor stream rich in C 2 and lighter components and a liquid stream rich in C 3 and heavier components; (3) passing the vapor stream from step (2) through the vapor phase hydrogenation reactor [ 33 ] to vapor phase hydrogenate; recycling a portion of a C 4 -C 10 process stream to the mixed phase hydrogenation reactor [ 24 ], and passing the other portion to the downstream separation zones; and (4) passing the effluent from the vapor phase hydrogenation reactor [ 33 ] to further separation zones.