Process for purifying a C4 and/or C5 hydrocarbon cut containing water and dimethyl ether as impurities

摘要

A C4 and/or C5 olefinic hydrocarbon cut, containing dimethyl ether and water as impurities, in a relative proportion of dimethyl ether to water of at most 5:1, is purified in a distillation zone where it is introduced at an intermediate level, distant from the top or from the bottom thereof by at least 3 theoretical plates, optionally with a stripping gas, and separated into a overhead fraction comprising an aqueous liquid phase and a hydrocarbon liquid phase at least partially recycled as reflux to the upper part of the distillation zone, and a bottom fraction formed of the purified C4 and/or C5 olefinic cut.