PROCESS FOR SELECTIVE HYDROGENATION OF CRACKED HYDROCARBONS

摘要

The invention relates to a process to selectively hydrogenate di-olefinically, poly-olefinically, and acetylenically unsaturated hydrocarbon components a C2 to C5+ or a C3 to C5+ fraction of a cracked hydrocarbon stream. The process comprises removing from a deethanizer or depropanizer a heavy stream enriched in a C3 to C5+ or a C4 to C5+ fraction; reacting the heavy stream with hydrogen for selective hydrogenation; and returning at least a portion of the hydrogenated stream to the deethanizer or depropanizer. Embodiments are disclosed where the heavy stream is removed by a side draw or by means of the reboiler circuit. The invention is applicable to front-end demethanizer, deethanizer, or depropanizer fractional distillation process sequences such as may be used with steam cracking or catalytic cracking.