Separation of acetylene and ethylene from cracked gas

Claim 1

In a method of joint separation of acetylene and ethylene from cracked gas which has been obtained by cracking liquid hydrocarbon fractions by means of a flame burning beneath the surface of said hydrocarbons from which the carbon dioxide and hydrogen sulfide have been removed and the cracked gas is dried by condensation the improvement which comprises cooling said hydrocarbons to a temperature which is above the solidification temperature of acetylene in admixture with the other condensable constituents and which is in the range of -82* to -120* C., the condensate thus obtained being separated and the remaining gas mixture containing small amounts of acetylene being freed from acetylene by scrubbing with a liquid consisting of ethylene, ethane or a mixture thereof, the gas mixture devoid of acetylene then being cooled to from -140* to -170* C., separating the condensate from the gas which has been cooled to from -140* to -170* C., warming said gas to -130 * to -100* C. countercurrent to the gas leaving the ethylene scrubber, and flashing said gas in a flash unit while performing external work so that the gas mixture is cooled and is used for countercurrent cooling in the condensation stages.