A dual riser FCC process for converting C.sub.3/C.sub.4-containing
feedstocks to aromatics. First and second hydrocarbon feeds (5, 6) are
supplied to the respective first and second risers (2, 4) in a dual-riser
FCC unit with a gallium enriched catalyst to make an effluent rich in
ethylene, propylene and aromatics. The first riser (2) is operated at
less severe conditions than the second riser (4) and can receive a
relatively heavy feed such as gas oil. The feed to the second riser (4)
includes propane, for example LPG, propane recycle from the C3 splitter
(72), etc. The FCC catalyst can include gallium to promote aromatics
formation.