Diacritic cracking of hydrocarbon feeds for selective production of

Abstract

A continuous process for the selective production of ethylene by the diacritic cracking of heavy hydrocarbon feeds such as residual oils, heavy vacuum gas oils, atmospheric gas oils, crude oils and coal-derived liquids. The diacritic cracking takes place in a non-tubular multi-zone reactor at elevated pressures (e.g. 70-1000 p.s.i.a.) A fuel is combusted with oxygen in the first section of the multi-zone reactor. The high temperature products of combustion of the first zone pass into a second section of the reactor where the feed is atomized and cracked to yield products including ethylene, acetylene and synthesis gas. The reaction products of the second zone then pass into a third section in which they are quenched. In each stage of the reactor the present process seeks to prevent the build-up of coke deposits on the walls of the reactor. In the first two stages, a film of gas such as CO.sub.2 or N.sub.2 is injected along the inner walls to prevent build-up of coke. In the quench section, the liquid material introduced as the quenching fluid also acts as a barrier to prevent coking.