Abstract: A process to separate a multi-component hydrocarbon stream which includes ethylene and other components with at least some of the components being present in a number of phases, is provided. The process includes in a first flash stage, flashing the multi-component hydrocarbon stream, from an elevated pressure and temperature to a pressure in the range of 10-18 bar(a), producing a first ethylene-containing vapor stream at a pressure in the range of 10-18 bar(a) and a multi-phase stream which includes some ethylene. In a second flash stage, the multi-phase stream is flashed to a pressure of less than 6 bar(a), producing a second vapor stream at a pressure of less than 6 bar(a) and a bottoms stream. The first ethylene-containing vapor stream is removed from the first flash stage, the second vapor stream is removed from the second flash stage and the bottoms stream is removed from the second flash stage.

Abstract: A process for producing hydrocarbons involves allowing reactants forming part of a reaction medium in a reaction zone, to react at reaction conditions so as to form primary hydrocarbon products. Water is formed as a by-product. The by-product water, on formation under the reaction conditions, is allowed to permeate through a porous membrane, thereby to be separated from the reaction medium.