GB800320A - Process for the treatment of gases containing ethylene - Google Patents

Abstract

Ethylene for polymerization is purified by subjecting it to the following processes in the order given, scrubbing the gas with water under pressure, scrubbing the gas with a caustic alkaline solution, subjecting the gas to hydrogenation in the presence of a catalyst containing a metal of the 8th group whereby acetylene compounds are selectively hydrogenated and drying the gas. In an example, a gas comprising 92.6 per cent by volume of ethylene and small quantities of ethane, acetylene, carbon dioxide and oxygen was compressed and washed with water in a tower packed with Raschig rings, the compressed gas was then circulated through a second tower and washed with sodium hydroxide solution and then heated to 100 DEG C. and passed through a tower together with hydrogen over a hydrogenation catalyst consisting of kieselguhr, nickel and alumina, finally moisture was removed by cooling to - 10 DEG C. and passing through silica gel, granular calcium chloride, and granular pumice which had been soaked with caustic potash solution. The resulting purified ethylene may be polymerised by passing it at a pressure of 2 kg./sq. cm. at 20 DEG to 60 DEG C. through a catalyst consisting of diethyl aluminium monochloride with titanium tetrachloride in a C9-C11 saturated aliphatic hydrocarbon fraction.ALSO:Ethylene is purified, particularly with a view to subsequent polymerization by subjecting it to the following processes in the order given: scrubbing the gas with water under pressure, scrubbing the gas with a caustic alkaline solution, subjecting the gas to hydrogenation in the presence of a catalyst containing a metal of the 8th Group whereby acetylene compounds are selectively hydrogenated and drying the gas. In an example, a gas comprising 92.6 per cent by volume of ethylene and small quantities of ethane, acetylene, carbon dioxide and oxygen was compressed and washed with water in a tower packed with Raschig rings, the compressed gas was then circulated through a second tower and washed with sodium hydroxide solution and then heated to 100 DEG C. and passed through a tower together with hydrogen over a catalyst consisting of kieselguhr, nickel and alumina, finally moisture was removed by cooling to -10 DEG C. and passing through silica gel, granular calcium chloride, and granular pumice which had been soaked with caustic potash solution. The resulting purified ethylene may be polymerized by passing it at a pressure of 2 kg./sq. cm. at 20 DEG to 60 DEG C. through a catalyst consisting of diethyl aluminium monochloride, titanium tetrachloride and a C9-C11 hydrocarbon fraction.