Patent ID: 6791002
Filing Date: 2004-09-14
Classification: C07C

Abstract:
A process for selectively converting hydrocarbons to ethylene and propylene comprising:feeding a hot catalyst into each of at least two riser reactors; feeding a free hydrocarbon gas into one of the riser reactor at a temperature significantly less than the catalyst temperature; contacting the hydrocarbon gas and the catalyst to convert some of the gas to ethylene and propylene, and for a time less than that needed for the gas temperature to rise 40% of the difference in temperature between the hot catalyst and the gas and generating an intermediate gas stream; separating the intermediate gas stream into a product stream comprising ethylene and propylene, and at least a substantially aromatics free light recycle stream and a substantially aromatics free heavy recycle stream; feeding the light recycle stream into one of the reactors; and feeding the heavy recycle stream into a second reactor.