Process to regenerate fcc spent catalyst

Abstract

A process to supply solid particles to a fluidized bed via a riser which has a substantially vertical upper part terminating at an outlet opening in the fluidized bed and wherein the solid particles are transported towards the fluidized bed in the riser with a lift gas, which lift gas and solid particles are contacted at an upstream part of the riser and wherein between the upstream part and the outlet opening the interior of the riser is provided with a plurality of axially spaced mixing elements.

1 . A process to supply solid particles to a fluidized bed via a riser which has a substantially vertical upper part terminating at an outlet opening in said fluidized bed and wherein the solid particles are transported towards said fluidized bed in the riser with a lift gas, which lift gas and solid particles are contacted at an upstream part of the riser and wherein between said upstream part and the outlet opening the interior of the riser is provided with a plurality of axially spaced mixing elements.  
   
   
       2 . The process of  claim 1 , wherein the mixing element has the shape of a segment of arc.  
   
   
       3 . The process of  claim 2 , wherein 
 a first disk surrounds the upper opening of the riser at the uppermost end of said riser;    a second disk, is spaced upwardly from, and rigidly connected to, said first disk, thereby forming a substantially open space there-between;    a deflection cone is attached, at its base, to said second disk, said deflection cone pointing downward and being centred over the outlet of said conduit, said deflection cone adapted to direct said spent catalyst and said transfer gas in a substantially uniform, radially outward direction through said space formed between said first disk and said second disk, thereby providing a continuous circumferential discharge of said mixture of solids and lift gas from the outer circumference of said space formed between said first disk and said second disk into said fluidised bed in a substantially uniform radially outward direction.    
   
   
       4 . The process of  claim 3 , wherein the solid particles are FCC catalyst particles, which are supplied to a fluidized regenerator bed.  
   
   
       5 . The process of  claim 4 , wherein the lift gas is air.  
   
   
       6 . The process of  claim 1 , wherein 
 a first disk surrounds the upper opening of the riser at the uppermost end of said riser;    a second disk, is spaced upwardly from, and rigidly connected to, said first disk, thereby forming a substantially open space there-between,    a deflection cone is attached, at its base, to said second disk, said deflection cone pointing downward and being centred over the outlet of said conduit, said deflection cone adapted to direct said spent catalyst and said transfer gas in a substantially uniform, radially outward direction through said space formed between said first disk and said second disk, thereby providing a continuous circumferential discharge of said mixture of solids and lift gas from the outer circumference of said space formed between said first disk and said second disk into said fluidised bed in a substantially uniform radially outward direction.    
   
   
       7 . The process of  claim 1 , wherein the solid particles are FCC catalyst particles, which are supplied to a; fluidized regenerator bed.  
   
   
       8 . The process of  claim 2 , wherein the solid particles are FCC catalyst particles, which are supplied to a; fluidized regenerator bed.