Processes for converting a hydrocarbon-containing feed by pyrolysis and gasification/combustion. The hydrocarbon-containing feed and heated particles can be fed into a pyrolysis zone and contacted therein to effect pyrolysis of the hydrocarbons and produce a pyrolysis effluent. A gaseous stream rich in olefins and a particle stream rich in particles that include coke disposed thereon can be obtained from the pyrolysis effluent. A CO.sub.2-rich stream that includes, on a dry basis, CO.sub.2 at a concentration 90 vol %, based on the total volume of the CO.sub.2-rich stream, can be obtained from the gasification/combustion gas mixture.

A feed injector for a circulating fluid bed reactor is fitted with a discharge nozzle with a circular, radially notched discharge orifice to improve the surface-to-volume ratio of the spray pattern formed by the nozzle. The feed injector is useful for injecting fluids into various types of circulating fluid bed reactors in which good contact between the components of the fluidized bed and the injected fluid is required. It is particularly useful in fluid coking reactors.

Processes for upgrading a hydrocarbon-containing feed. The feed and a first particle stream can be contacted under pyrolysis conditions to effect pyrolysis of the feed to produce a pyrolysis effluent that can include olefins and the particles, where coke can be formed on the particles. A first gaseous stream and a second particle stream can be obtained from the pyrolysis effluent. At least a portion of the first gaseous stream can be contacted with oligomerization catalyst particles under oligomerization conditions to effect oligomerization of at least a portion of olefins in the first gaseous stream.