Patent ID: 7112307

Claim:
A riser reactor apparatus for the conversion of a hydrocarbon feedstock to a hydrocarbon gas comprising ethylene and propylene comprising: a plurality of riser reactor units wherein each riser reactor unit includes a plurality of sections, a catalyst inlet port, a plurality of gas inlet ports and a gas-catalyst outlet port, and wherein each gas inlet port enters at a different section of the riser reactor unit, and wherein the plurality of riser reactor units are arranged in series such that the gas-catalyst outlet port of a preceding reactor unit is in fluid communication with the catalyst and gas inlet ports of a successive reactor unit; a plurality of gas-catalyst separation units, each separation unit with an inlet port in fluid communication with each riser reactor unit gas-catalyst outlet port, each separation unit further comprising a gas outlet port and a catalyst outlet port; a catalyst regeneration unit with an inlet port in fluid communication with the catalyst outlet port of at least one of said gas-catalyst separation units, and a catalyst outlet port in fluid communication with the catalyst inlet port of at least one of said riser reactor units; a manifold having an inlet port and a plurality of outlet ports, wherein the manifold inlet port is in fluid communication with the catalyst regeneration unit catalyst outlet port, and each riser reactor unit catalyst inlet port is in fluid communication with one of said outlet ports of the manifold; a hydrocarbon separation unit having a gas inlet port in fluid communication with the gas-catalyst separation unit gas outlet ports, wherein the hydrocarbon separation unit separates ethylene and propylene from the hydrocarbon gas; and at least one heat exchanger disposed between the gas-catalyst separation unit of a preceding reactor unit and a successive reactor unit for changing the temperature of the catalyst from the preceding reactor unit before directing the catalyst to the successive reactor unit, wherein said at least one heat exchanger comprises an inlet port in fluid communication with the gas-catalyst separation unit catalyst outlet port of the preceding reactor unit and an outlet port in fluid communication with the successive reactor unit catalyst inlet port.