Duocracking process for the production of olefins from both heavy and light hydrocarbons

Claim 1

A process for the thermal cracking of heavy hydrocarbon feed selected from the group consisting of naphtha, kerosene, atmospheric gas oil, vacuum gas oil and resid to produce olefins comprising: (a) diluting the heavy hydrocarbon feed with steam in a ratio of 0.2 or less pound of steam per pound of heavy hydrocarbon; (b) elevating the temperature of the heavy hydrocarbon with the steam diluent to a temperature to effect partial thermal cracking; (c) mixing a stream of light hydrocarbon feedstock selected from the group consisting of ethane, propane, propylene, normal and iso-butane, raffinates and naphthas, or their mixtures, which light hydrocarbon is lighter than the heavy hydrocarbon feed with steam diluent; (d) thermally cracking the light hydrocarbon feedstock to completion to produce principally olefins; (e) delivering the completely cracked light hydrocarbon effluent to the stream of partially cracked heavy hydrocarbon to form a composite stream, said light hydrocarbon effluent providing heat for subsequent cracking and serving as a diluent for the partially cracked heavy hydrocarbon; (f) further cracking the composite stream; and (g) quenching the effluent from the cracked composite stream of heavy and light hydrocarbon to terminate the reactions.