An FCC process uses a highly efficient separation device to remove product from the catalyst so that the reactor vessel receives a low volume of feed hydrocarbons and riser by-products. The separation device encloses an upwardly directed outlet end of a ballistic separation device in low volume disengaging vessel that collects disengaged catalyst from the riser in a dense bed. Immediate contact of the dense bed with a stripping fluid minimizes the amount of hydrocarbons that are carried out of the disengaging vessel into the open volume of the reactor vessel.