Verfahren zur gemeinsamen Abtrennung von Acetylen und AEthylen aus Spaltgasen

1,187,809. Acetylene and ethylene. BADISCHE ANILIN- & SODA-FABRIK A.G. 11 Aug., 1967 [12 Aug., 1966], No. 36972/67. Heading C5E. [Also in Division F4] Joint separation of acetylene and ethylene together with some methane and ethane from cracked gas obtained by a flame burning beneath the surface of petroleum and containing carbon monoxide, hydrogen, oxygen nitrogen, C 3 to C 5 hydrocarbons together with carbon oxysulphide and carbon disulphide is effected by drying and compressing the cracked gas at 2, 4 condensing part of the methane and the whole of the remaining hydrocarbons, C5 2 and COS in a heat exchanger 9, separating them at 10, 11 vaporizing the separated condensate in said heat exchanger 9, compressing the vapour at 15 and thereafter passing said separated fraction under pressure through lines 12, 12b, 19 into a rectification column 6 from which product ethylene and acetylene vapour containing methane and ethane is withdrawn through a line 25 whilst liquid bottoms containing the whole of the C 3 to C 5 hydrocarbons, C5 2 and COS are withdrawn through a line 27. Said liquid bottoms may be returned through a line 29 to the burner of the cracking plant or is vaporized at 28 and returned to the feed line 8 of heat exchanger 9 which latter is cooled by a return flow of uncondensed gases from separators 10, 11 after expansion in a turbine 14. The concentration of acetylene in column 6 is maintained below a predetermined safe level by adding a mixture of methane, ethylene and ethane in a line 20 to the feed in line 19. Exchanger 9 is cooled by vapour withdrawn from separator 10 and expanded in a turbine 14.