Apparatuses and methods are provided for regenerating catalyst particles. In one embodiment, a method for regenerating catalyst particles includes passing the catalyst particles through a halogenation zone and a drying zone. The method feeds drying gas to the drying zone and passes a first portion of the drying gas from the drying zone to the halogenation zone. The method includes removing a second portion of the drying gas from the drying zone and injecting a halogen gas into the second portion of the drying gas. Further, the method includes delivering the halogen gas and the second portion of the drying gas to the halogenation zone. In the method, substantially all of the drying gas fed to the drying zone enters the halogenation zone.

Light olefins may be produced from hydrocarbons by a method including passing a hydrocarbon feed stream into a feed inlet of a reactor. The reactor may include an upper reactor portion defining an upper reaction zone and a lower reactor portion defining a lower reaction zone. The catalyst may move in a generally downward direction through the upper reactor portion and the lower reactor portion, and the hydrocarbon feed stream may move in a generally upward direction through the upper reactor portion and lower reactor portion such that the hydrocarbon feed stream and the catalyst move with a counter-current orientation. Contacting the catalyst with the hydrocarbon feed stream may crack one or more components of the hydrocarbon feed stream and form a hydrocarbon product stream. The method may further include passing the hydrocarbon product stream out of the upper reaction zone through the hydrocarbon product outlet.

Light olefins may be produced from hydrocarbons by a method including passing a hydrocarbon feed stream into a feed inlet of a reactor. The reactor may include an upper reactor portion defining an upper reaction zone and a lower reactor portion defining a lower reaction zone. The catalyst may move in a generally downward direction through the upper reactor portion and the lower reactor portion, and the hydrocarbon feed stream may move in a generally upward direction through the upper reactor portion and lower reactor portion such that the hydrocarbon feed stream and the catalyst move with a counter-current orientation. Contacting the catalyst with the hydrocarbon feed stream may crack one or more components of the hydrocarbon feed stream and form a hydrocarbon product stream. The method may further include passing the hydrocarbon product stream out of the upper reaction zone through the hydrocarbon product outlet.

A system for preventing a catalyst from overheating is provided. The system includes: a first reactor filled with a catalyst at least in part and configured to receive reaction gas and produce product gas; and a second reactor configured to cool a catalyst discharged from the first reactor. The catalyst is circulated between the first reactor and the second reactor by injecting the catalyst cooled in the second reactor into the first rector.

A system for preventing a catalyst from overheating is provided. The system includes: a first reactor filled with a catalyst at least in part and configured to receive reaction gas and produce product gas; and a second reactor configured to cool a catalyst discharged from the first reactor. The catalyst is circulated between the first reactor and the second reactor by injecting the catalyst cooled in the second reactor into the first rector.

The invention relates to a cyclone (10) for mechanical separation of particles in suspension in a gas, in particular intended for a fluid catalytic cracking unit, said cyclone comprising the following elements:

a separation chamber (101),

an inlet duct (102) that opens into the chamber (101),

a gas outlet duct (103) located in the upper portion of the chamber (101) and

a particle outlet duct (104) located in the lower portion of the chamber (101), characterized in that each element of the cyclone is made of a ceramic material.

The invention also relates to a fluid catalytic cracking unit equipped with at least one cyclone made of ceramic material.

The invention relates to a cyclone (10) for mechanical separation of particles in suspension in a gas, in particular intended for a fluid catalytic cracking unit, said cyclone comprising the following elements:

a separation chamber (101),

an inlet duct (102) that opens into the chamber (101),

a gas outlet duct (103) located in the upper portion of the chamber (101) and

a particle outlet duct (104) located in the lower portion of the chamber (101), characterized in that each element of the cyclone is made of a ceramic material.

The invention also relates to a fluid catalytic cracking unit equipped with at least one cyclone made of ceramic material.

A method is provided for increasing production of middle distillate hydrocarbons from conversion of a heavy hydrocarbon feed in a fluid catalytic cracking system having a primary riser and a secondary riser, wherein the method comprises providing regenerated catalyst to the primary riser and operating the primary riser under severe conditions and providing spent catalyst to the secondary riser and operating the secondary riser under moderate conditions.

A method is provided for increasing production of middle distillate hydrocarbons from conversion of a heavy hydrocarbon feed in a fluid catalytic cracking system having a primary riser and a secondary riser, wherein the method comprises providing regenerated catalyst to the primary riser and operating the primary riser under severe conditions and providing spent catalyst to the secondary riser and operating the secondary riser under moderate conditions.

Vent gases from a catalyst cooler are directed downstream or outside of the catalyst regenerator to avoid sending air to a location where after burn may occur. Vent gases contain oxygen that when contacted with carbon monoxide in regenerator flue gas can cause after burn to occur at a location which lacks sufficient catalyst density to serve as a heat sink. Locating the cooling media supply in the top of the catalyst cooler enables cooled catalyst to drain from the bottom of the catalyst cooler and fitting more cooler tubes in the catalyst cooler.