Patent ID: 7437891

Claim:
A process for the recovery of ethylene from a gas mixture comprising ethylene, ethane, acetylene, methane, hydrogen, C3 components, and components heavier than propane, comprising: (a) directing the gas mixture to a first distillation column and recovering therefrom a first vapor overhead stream comprising ethane, ethylene, acetylene, hydrogen, methane, and C3 components, and a first bottoms stream comprising components heavier than propane and optionally C3 components; (b) removing acetylene from the first vapor overhead stream to produce a low-acetylene first overhead stream; (c) separating at least a portion of the low acetylene first overhead stream through the use of one or more distillation columns, one of which acts as an ethylene distributor column, to recover an ethane-free vapor stream comprising ethylene, methane and hydrogen and substantially free of ethane, a first liquid stream comprising ethylene, ethane and components heavier than ethane, and a second liquid stream comprising ethylene and ethane and substantially free of components heavier than ethane; (d) separating the ethane-free vapor stream of step (c), above, into a light stream enriched in hydrogen and one or more streams depleted in hydrogen and comprising ethylene, said separation comprising at least one step of chilling at least a portion of the ethane-free vapor stream of step (c), above; (e) directing at least a portion of at least one of the one or more streams depleted in hydrogen to a demethanizer distillation column and withdrawing therefrom a demethanizer overhead stream comprising methane and hydrogen and substantially free of ethylene and a demethanizer bottoms stream comprising purified ethylene; (f) recovering a second purified ethylene product from the first and second liquid streams of step (c), above; (g) directing at least a portion, of step (c), above, of the low-acetylene first overhead stream to a C2s distributor distillation column and recovering therefrom a C2s distributor overhead stream comprising ethylene, ethane, methane and hydrogen and substantially free of components heavier than ethane, and a C2s distributor bottoms stream comprising ethylene, ethane, and components heavier than ethane and substantially free of components lighter than ethylene; (h) withdrawing the C2s distributor bottoms stream as the first liquid stream of step (c), above; (i) directing at least a portion of the C2s distributor overhead stream to an ethylene distributor column and recovering therefrom an ethylene distributor overhead stream comprising ethylene, methane, and hydrogen and substantially free of ethane and an ethylene distributor bottoms stream comprising ethylene and ethane and substantially free of components lighter than ethylene; (j) withdrawing the ethylene distributor overhead stream as the ethane-free vapor stream of step (c), above; and (k) withdrawing the ethylene distributor bottoms stream as the second liquid stream of step (c), above.