Abstract: A process for fluidized catalytic cracking of heavy oils and production of hydrogen is described, comprising contacting steam and heavy oils with fluidized catalyst particles containing reduced iron at high temperatures, wherein a fluidized bed is formed such that the catalyst particles are fed from the bottom and withdrawn from the top of the fluidized bed and the fluidized bed is provided with a means for retarding the mixing rate of the catalyst particles in the vertical direction, to thereby generate a temperature difference between zones of the fluidized bed above and below said means, and use the upper zone for cracking of heavy oils and the lower zone for production of hydrogen. Catalyst particles withdrawn from the fluidized bed may be regenerated and recycled. Thus, light oils and hydrogen can be produced in high yields.

Abstract: A process for simultaneously cracking heavy hydrocarbons to form light oil and producing hydrogen is described, which comprises (1) a first step wherein steam and heavy hydrocarbons are simultaneously contacted with a catalyst in a reduced state, containing iron in the form of iron oxide, to produce hydrogen, cracked gases and cracked light oils, to convert the reduced-state catalyst into an oxidized-state catalyst, and to deposit coke on the catalyst, (2) a second step wherein the oxidized-state catalyst with coke deposited thereon is contacted with an oxygen-containing gas to partially combust the coke on the catalyst, to convert the oxidized-state catalyst into a reduced-state catalyst, and to fix a sulfur compound contained in the coke as iron sulfide with a part of the reduced-state catalyst; and (3) a third step wherein catalyst obtained from the first step, the major portion of the catalyst being recycled between the first step and second step, is contacted with an oxygen-containing gas at a temperatur