The present invention relates to a device and to a process for the fluidized bed catalytic cracking of a hydrocarbon feedstock, in which: a first feedstock (2) is cracked in a dense fluidized bed reactor (1) in the presence of a catalyst (3) to produce a first effluent; and at least one second feedstock (10) is cracked in a transport fluidized bed reactor (4) in the presence of the catalyst (3) supplied by the dense fluidized bed reactor (1) to produce a second effluent, the second feedstock (10) being a heavier feedstock than the first feedstock (2).

The present invention relates to a device and to a process for the fluidized bed catalytic cracking of a hydrocarbon feedstock, in which: a first feedstock (2) is cracked in a dense fluidized bed reactor (1) in the presence of a catalyst (3) to produce a first effluent; and at least one second feedstock (10) is cracked in a transport fluidized bed reactor (4) in the presence of the catalyst (3) supplied by the dense fluidized bed reactor (1) to produce a second effluent, the second feedstock (10) being a heavier feedstock than the first feedstock (2).

The present invention relates to a device and to a process for the fluidized bed catalytic cracking of a hydrocarbon feedstock, in which: a first feedstock (2) is cracked in a dense fluidized bed reactor (1) in the presence of a catalyst (3) to produce a first effluent; and at least one second feedstock (10) is cracked in a transport fluidized bed reactor (4) in the presence of the catalyst (3) supplied by the dense fluidized bed reactor (1) to produce a second effluent, the second feedstock (10) being a heavier feedstock than the first feedstock (2).

Higher temperature regenerated dehydrogenation catalyst is mixed with the lower temperature spent dehydrogenation catalyst from a dehydrogenation reaction to heat the spent catalyst. Air or other oxygen containing gas may be introduced to facilitate mixing. The mixing of hot regenerated catalyst with cooler spent catalyst increases the temperature of the spent catalyst and makes the coke on catalyst and in the supplemental fuel gas instantly ready to combust without the delay necessary to heat up the spent catalyst to combustion temperature. The regenerated dehydrogenation catalyst may be mixed with the spent dehydrogenation catalyst before the mixture of catalyst is contacted with the supplemental fuel gas. Combustion with fuel gas should be conditioned to avoid generation of a flame.

A method for fluidizing a spent catalyst in a regenerator during a combustion process. The combustor includes a vessel and an air distributor. The air distributor includes an air grid and a plurality of first nozzles extending from the air grid. Spent catalyst is introduced into the vessel. Air is provided to the vessel via the plurality of first nozzles at a base combustion air rate. Additional air is provided to the vessels via a plurality of second nozzles of a fluffing air distributor at a fluffing air rate that is between 0.5 wt % and 10 wt % of the base combustion air rate to fluidize the catalyst. The second nozzles have outlets that are disposed below the air grid and above a bottom head of the vessel.

A method for fluidizing a spent catalyst in a regenerator during a combustion process. The combustor includes a vessel and an air distributor. The air distributor includes an air grid and a plurality of first nozzles extending from the air grid. Spent catalyst is introduced into the vessel. Air is provided to the vessel via the plurality of first nozzles at a base combustion air rate. Additional air is provided to the vessels via a plurality of second nozzles of a fluffing air distributor at a fluffing air rate that is between 0.5 wt % and 10 wt % of the base combustion air rate to fluidize the catalyst. The second nozzles have outlets that are disposed below the air grid and above a bottom head of the vessel.

A counter-current catalyst regenerator with at least two stages of counter-current contact is proposed. Each stage may comprise a permeable barrier that allows upward passage of oxygen-containing gas and downward passage of coked catalyst into each stage, but inhibits upward movement of catalyst to mitigate back mixing and approximate true counter-current contact and efficient combustion of coke from catalyst.

A counter-current catalyst regenerator with at least two stages of counter-current contact is proposed. Each stage may comprise a permeable barrier that allows upward passage of oxygen-containing gas and downward passage of coked catalyst into each stage, but inhibits upward movement of catalyst to mitigate back mixing and approximate true counter-current contact and efficient combustion of coke from catalyst.

A fluid catalytic cracking unit (FCCU) for production of petrochemical feedstock fractions comprises a first reactor to receive a stream of desalinated crude oil and produce a first cracked product stream; a second reactor to receive a stream of light cracked naphtha (LCN) and produce a second cracked product stream; a third reactor to receive a bottom stream and produce a third cracked product stream; and a fractionating column and gas concentration section to separate components of the first cracked product stream, the second cracked product stream, and the third cracked product stream to produce, upon further fractionation, Ethylene, Propylene, Butylene, Benzene, Toluene and Xylene as the petrochemical feedstock fractions.

A fluid catalytic cracking unit (FCCU) for production of petrochemical feedstock fractions comprises a first reactor to receive a stream of desalinated crude oil and produce a first cracked product stream; a second reactor to receive a stream of light cracked naphtha (LCN) and produce a second cracked product stream; a third reactor to receive a bottom stream and produce a third cracked product stream; and a fractionating column and gas concentration section to separate components of the first cracked product stream, the second cracked product stream, and the third cracked product stream to produce, upon further fractionation, Ethylene, Propylene, Butylene, Benzene, Toluene and Xylene as the petrochemical feedstock fractions.