The present invention is directed to a hydrocarbon conversion apparatus and process. The apparatus comprises the following: a plurality of riser reactors, each having a first end into which a catalyst is fed, a second end through which the catalyst can exit, and optionally a center axis extending therebetween. The apparatus also includes a separation zone having a plurality of inlets, each inlet not being oriented along the center axes of the riser reactors, the separation zone being provided to separate the catalyst from products of a reaction conducted in the hydrocarbon conversion apparatus. A plurality of deviating members are also provided, each deviating member being in fluid communication between the second end of a respective riser reactor and a respective inlet of the separation zone. The apparatus also includes a catalyst retention zone provided to contain catalyst, which is fed to the riser reactors. A catalyst return is in fluid communication between the separation zone and the catalyst retention zone.