A reactor apparatus and process for contacting hydrocarbons with catalyst. The reactor apparatus comprises a plurality of tubular reactors each having a first end into which a catalyst is fed and a second end through which the catalyst and product exit the tubular reactor. A catalyst retention zone is provided to contain catalyst and feed catalyst to the tubular reactors. A separation zone is provided to separate the catalyst from products of a reaction conducted in the apparatus. A transport conduit having a first end in fluid communication with the second ends of at least two of the tubular reactors and a second end extending into the separation zone transports product and catalyst to the separation zone. A catalyst return in fluid communication with the separation zone and the catalyst retention zone returns catalyst to the catalyst retention zone.