Fluid catalytic cracking process and apparatus for more effective regeneration of zeolite catalyst

Claim 1

A process for regenerating a spent fluid catalytic cracking catalyst stream, comprising the steps of: combining said spent catalyst stream with a first oxygen-containing stream to form a mixture, wherein said spent fluid catalytic cracking catalyst stream comprises, as a first catalyst component, particles of a cracking catalyst which requires relatively frequent regeneration and, as a second catalyst component, particles of a catalyst which requires less frequent regeneration than the first catalyst component, at least one physical characteristic of said particles of said first catalyst component differs sufficiently from at least one physical characteristic of said particles of said second catalyst component as to permit their separation; passing said mixture through a first regenerator riser at catalyst regeneration conditions; discharging said mixture from said riser; separating a first flue gas stream from said discharged mixture, and passing a remainder of said mixture to a first catalyst bed located in a lower portion of a second regenerator riser; regenerating catalyst in said first bed by contacting said first bed with a second oxygen-containing stream; upwardly passing a first portion of partially regenerated catalyst from said first bed to an upper portion of said second riser and downwardly withdrawing a second portion of partially regenerated catalyst from said first bed; discharging said first portion of partially regenerated catalyst from said second riser into a catalyst collecting chamber; separating a second flue gas stream from said discharged first portion of partially regenerated catalyst and passing a remainder of said first portion to a second catalyst bed located in said collecting chamber; regenerating catalyst in said second bed by contacting said second bed with a third oxygen-containing stream; withdrawing a first portion of regenerated catalyst from said second bed; and withdrawing a third flue gas stream from an atmosphere of said collecting chamber, wherein said first catalyst portion of said first bed passes to an upper portion of said second riser; said catalyst which requires more frequent regeneration comprising large pore crystalline zeolite catalyst particles and said catalyst which requires less frequent regeneration comprising intermediate pore crystalline zeolite catalyst particles, said intermediate pore zeolite catalyst particles being sufficiently less elutriatable than said large pore zeolite catalyst particles, such that said second portion of partially regenerated catalyst from said first catalyst bed has a higher ratio of intermediate pore zeolite catalyst particles to large pore zeolite catalyst particles than said first portion of partially regenerated catalyst from said first catalyst bed, whereby the intermediate pore zeolite catalyst particles are separated from the large pore zeolite catalysts prior to said regenerating in said second bed and are then passed directly to a riser conversion zone of a fluid catalytic cracking reactor.

Claim 26

An apparatus for regenerating a spent fluid catalytic cracking catalyst stream, comprising: a first regenerator riser for passing a mixture of said spent catalyst stream and a first oxygen-containing stream therethrough at catalyst regeneration conditions, wherein said spent catalyst stream comprises particles of a first and second catalyst component, and particles of said first catalyst component are separable from particles of said second catalyst component according to at least one differing physical characteristic of said first and second catalyst component particles; means for discharging said mixture from said first riser; a second regenerator riser; first means for separating a first flue gas stream from said discharged mixture and directing a remainder of said mixture to a first catalyst bed located in a lower portion of said second regenerator riser; means for contacting catalyst in said first bed with a second oxygen-containing stream thereby regenerating said first bed catalyst; means for upwardly passing a first portion of catalyst from said first bed to an upper portion of said second riser and a conduit for downwardly withdrawing a second portion of catalyst from said first bed; means for discharging said first portion from said second riser into a catalyst collecting chamber; second means for separating a second flue gas stream from said discharged first portion and directing a remainder of said first portion to a second catalyst bed located in said collecting chamber; means for contacting catalyst in said second bed with a third oxygen-containing stream, thereby regenerating said second bed catalyst; a conduit for withdrawing a portion of regenerated catalyst from said second bed; and means for withdrawing a third flue gas stream from an atmosphere of said collecting chamber.

Claim 27

An apparatus for regenerating a spent fluid catalytic cracking catalyst stream, comprising: a first regenerator riser for passing a mixture of said spent catalyst stream and a first oxygen-containing stream therethrough at catalyst regeneration conditions, wherein said spent catalyst stream comprises particles of a first and second catalyst component, and particles of said first catalyst component are separable from particles of said second catalyst component according to at least one differing physical characteristic of said first and second catalyst component particles; means for discharging said mixture from said first riser; a second regenerator riser; first means for separating a first flue gas stream from said discharged mixture and directing a remainder of said mixture to a first catalyst bed located in a lower portion of said second regenerator riser; means for contacting catalyst in said first bed with a second oxygen-containing stream thereby regenerating said first bed catalyst; means for upwardly passing a first portion of catalyst from said first bed to an upper portion of said second riser and a conduit for downwardly withdrawing a second portion of catalyst from said first bed; means for discharging said first portion from said second riser into a catalyst collecting chamber; second means for separating a second flue gas stream from said discharged first portion and directing a remainder of said first portion to a second catalyst bed located in said collecting chamber; means for contacting catalyst in said second bed with a third oxygen-containing stream, thereby regenerating said second bed catalyst; a conduit for withdrawing a portion of regenerated catalyst from said second bed; and means for withdrawing a third flue gas stream from an atmosphere of said collecting chamber.

Claim 34

An apparatus for regenerating a spent fluid catalytic cracking catalyst system comprising ZSM-5 catalyst particles and zeolite Y catalyst particles from a fluid catalytic cracking reactor, comprising: a first regenerator riser for passing a mixture of said spent catalyst stream, a regenerated recycle catalyst and a first oxygen-containing stream therethrough at regenerating conditions; a second regenerator riser comprising an upper portion and a lower condition; means for discharging said mixture from said first riser into said lower portion of said second regenerator riser and downwardly directing said mixture from said first riser to a first catalyst bed located in said lower portion of said second riser; means for separating a first portion of flue gas from said discharged mixture, said means for separating comprising a riser cover which surrounds said means for discharging and directing; means for contacting catalyst in said first bed with a second oxygen-containing gas stream thereby regenerating said first bed catalyst; means for passing a first portion of catalyst from an upper portion of said first bed into said upper portion of said second riser and a conduit for withdrawing a second portion of catalyst from a lower portion of said first bed, said ZSM-5 catalyst particles being sufficiently less elutriatable than said zeolite Y catalyst particles, such that said second portion of said first bed catalyst has a higher ratio of ZSM-5 to zeolite Y than said first portion of said first bed catalyst; an enlarged catalyst collecting chamber comprising an upper portion and a lower portion; means for discharging said first portion from said second riser into said enlarged catalyst collecting chamber and downwardly directing said first portion from said second riser to a second catalyst bed located in said lower portion of said collecting chamber; means for withdrawing a second flue gas stream from said first portion prior to discharging said first portion from said second riser; means for contacting catalyst in said second bed with a third oxygen-containing gas stream thereby regenerating said second bed catalyst; a conduit for recycling said regenerated recycle catalyst from said second bed to said first riser; a conduit for withdrawing a first portion of regenerated catalyst from said second bed; means for withdrawing a third flue gas stream from an atmosphere of said collecting chamber above said second bed.

Claim 35

An apparatus for regenerating a spent fluid catalytic cracking catalyst system comprising ZSM-5 catalyst particles and zeolite Y catalyst particles from a fluid catalytic cracking reactor, comprising: a first regenerator riser for passing a mixture of said spent catalyst stream, a regenerated recycle catalyst and a first oxygen-containing stream therethrough at regenerating conditions; a second regenerator riser comprising an upper portion and a lower condition; means for discharging said mixture from said first riser into said lower portion of said second regenerator riser and downwardly directing said mixture from said first riser to a first catalyst bed located in said lower portion of said second riser; means for separating a first portion of flue gas from said discharged mixture, said means for separating comprising a riser cover which surrounds said means for discharging and directing; means for contacting catalyst in said first bed with a second oxygen-containing gas stream thereby regenerating said first bed catalyst; means for passing a first portion of catalyst from an upper portion of said first bed into said upper portion of said second riser and a conduit for withdrawing a second portion of catalyst from a lower portion of said first bed, said ZSM-5 catalyst particles being sufficiently less elutriatable than said zeolite Y catalyst particles, such that said second portion of said first bed catalyst has a higher ratio of ZSM-5 to zeolite Y than said first portion of said first bed catalyst; an enlarged catalyst collecting chamber comprising an upper portion and a lower portion; means for discharging said first portion from said second riser into said enlarged catalyst collecting chamber and downwardly directing said first portion from said second riser to a second catalyst bed located in said lower portion of said collecting chamber; means for withdrawing a second flue gas stream from said first portion prior to discharging said first portion from said second riser; means for contacting catalyst in said second bed with a third oxygen-containing gas stream thereby regenerating said second bed catalyst; a conduit for recycling said regenerated recycle catalyst from said second bed to said first riser; a conduit for withdrawing a first portion of regenerated catalyst from said second bed; means for withdrawing a third flue gas stream from an atmosphere of said collecting chamber above said second bed.