Abstract: A method, together with suitable apparatus therefor, is provided useful in recovering heat from a high temperature cracked hydrocarbon gas, in which a liquid wash is injected into the tubes of a vertically oriented multitube transfer line heat exchanger to minimize deposition of coke. The wash liquid is introduced into a plenum chamber located above the top tube sheet and it then flows through a perforated plate. This distributes the liquid uniformly over the plate where it flows into the tubes to dissolve and/or flux condensates and coke.

Abstract: The invention relates to an improvement in an integrated, two stage coking and steam cracking process for the production of unsaturated light hydrocarbons. A heavy hydrocarbonaceous oil is first coked in a fluidized bed coking zone. The vaporous conversion product is passed to a dilute phase. High temperature cracking in the presence of steam is carried out on the vaporous coker conversion product by injecting into the vapors a stream of hot coke particles at a sufficient temperature and in sufficient amount to raise the coker vapors to steam cracking temperature and supply the endothermic heat of reaction. Solids are separated from product gas in a gas-solids separation zone such as one or more cyclones and sent to the fluid coking zone and the gas is quenched to stop olefin degradation reactions. According to the improvement, relatively low temperature steam is introduced into contact with the separated solids to superheat the steam and cool the solids.

Abstract: The invention relates to an improvement in an integrated, two stage coking and steam cracking process for the production of unsaturated light hydrocarbons. A heavy hydrocarbonaceous oil is first coked in a fluid coking zone. High temperature cracking in the presence of steam is carried out on the vaporous coker conversion product by injecting into the vapors a stream of hot coke particles at a sufficient temperature and in sufficient amount to raise the coker vapors to steam cracking temperature and supply the endothermic heat of reaction. Solids are separated from gas in a gas-solids separation zone such as one or more cyclones and sent to the fluid coking zone and the gas is quenched to stop olefin degradation reactions. According to the improvement, a portion of the separated solids is diverted from entering the fluid coking zone so that the amount of separated solids it receives is only sufficient to satisfy its heat requirement. Solids may be diverted via the cyclone dipleg.