A process and apparatus for catalytic conversion of feedstock and separating catalyst from product gas comprises a first hydrocarbon feedstock contacted with a first stream of catalyst in a first riser to produce a first mixture of catalyst and product gases. A second hydrocarbon feedstock is contacted with a second stream of catalyst in a second riser to produce a second mixture of catalyst and product gases. The first riser and/or the second riser may terminate within a reactor vessel. The first mixture of catalyst and product gases from the first riser pass into a first disengagement chamber within the reactor vessel. The second mixture of catalyst and product gases pass from the second riser into a second disengagement chamber within the same reactor vessel.