Abstract: A method for separating vinyl chloride, which comprises cooling a cracked gas obtained by cracking 1,2-dichloroethane by a thermal cracking furnace, firstly in a heat exchanger, then further cooling it in a quenching tower and then distilling it, wherein the cracked gas is cooled in the heat exchanger to at least 350.degree. C., the quenching tower is controlled so that from 80 to 98 wt % of the cracked gas introduced is withdrawn as an overhead product and the rest of from 20 to 2 wt % of the cracked gas is withdrawn as a bottom effluent, and they are respectively sent to the subsequent steps, and formed coke is discharged together with the bottom effluent.

Abstract: Disclosed herein are a method of cleaning an oil-deposited material, which comprises cleaning a material having oils deposited on the surface thereof with a cleaning agent comprising 25 to 90% by weight of at least one of compounds selected from the group consisting of pyrrolidones, .gamma.-butyrolactone and N,N-dimethylacetamide, and 10 to 75% by weight of water, then eliminating at least a portion of the deposited cleaning agent from said material to be cleaned by a physical means, and then applying water-washing with water, steam or water and steam; an apparatus for cleaning an oil-deposited materialhaving oils deposited on the surface thereof; and a cleaning agent therefor.