摘要 |
A process for the separation of propylene from an input stream of C3 hydrocarbons containing propylene, possibly C4 and/or higher hydrocarbons, and MAPD (methyl acetylene and/or propadiene), comprises subjecting said input steam to fractional distillation to separate the propylene as an overhead stream leaving a bottoms stream containing said MAPD and any C4 and/or higher hydrocarbons. In order to avoid the need to slip substantial amounts of valuable propylene into the bottoms stream to maintain the concentration of MAPD in the bottoms stream at a safe level, a propane-containing stream is added to the input stream of C3 hydrocarbons so that the bottoms stream contains a substantial amount of propane. So that the propylene content of t he bottoms stream can be maintained at below 10% by weight, the amount of propane added to the input stream is such that the weight of propane, plus any propylene and C4 and/or higher hydrocarbons, in said bottoms stream is greater than the total weight of MAPD in said bottoms stream.
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