A process for deethanizing light hydrocarbons comprising olefins is
disclosed. A feed stream, comprising ethylene, ethane, propylene, and
propane, is supplied to a primary deethanizer 24, having absorption and
stripping sections. The absorption section produces an overhead vapor
effluent 128, consisting primarily of ethylene and ethane, which is
supplied to a C2 splitter to separate ethane and ethylene. The stripping
section produces a primary deethanizer bottoms stream having an ethane
concentration from 1 to 20 mole percent of the feed ethane. The primary
deethanizer bottoms 120 are cooled and supplied to a secondary
deethanizer 142 having absorption and stripping sections. The absorption
section is refluxed, producing an overhead effluent 154 essentially free
of ethylene. The stripping section is refluxed to produce a secondary
deethanizer bottoms stream essentially free of ethane. The secondary
deethanizer bottoms stream is supplied to a depropanizer or C3 splitter
for separation of the remaining olefins.