process for the officers fulfil separate of unsaturated aliphatic hydrocarbons, in particular ethylene from mixtures

摘要

1431946 Separating hydrocarbons STANDARD OIL CO 4 May 1973 [12 May 1972 13 Sept 1972] 21365/73 Heading C5E Aliphatically unsaturated hydrocarbon having 2 to 8 carbon atoms is separated from a mixture by selectively transferring it across a barrier which comprises an aqueous component containing metal ions which combine with the unsaturated hydrocarbon to form a water soluble complex and a semi-permeable member which is solid, water-insoluble and impermeable to the aqueous component; the partial pressure of the unsaturated hydrocarbon on the second side of the barrier being maintained lower than that on the first side so that the unsaturated hydrocarbon is released on the second side of the barrier. The metal ions can be silver, zinc or cuprous ammonium and the aqueous component can comprise silver nitrate, optionally together with UO 2 (NO 3 ) 2 or a nitrate of Cr, Ni, Zn, Cd, Al, Li, Sr, Ca, Mg, Co, FeSP3+/SP, Na, Pb, NH 4 or K. The semi-permeable membrane can comprise polyurethane, nylon, sodium cellulose xanthate or an ethylene glycol monomethacrylate polymer. The process can be used to separate acetylene and/or ethylene from mixtures which also comprise methane and/or ethane. Many examples are given in which the aqueous component is in the form of a liquid covering the first side of the semi-permeable membrane which is either in the form of a flat sheet or a hollow tube immersed in the liquid; alternatively the aqueous component can be held within the semi-permeable membrane, e.g. by being absorbed therein or absorbed on a material such as cellulose acetate which is held between two semi-permeable sheets.