US 4,309,273 A · Removal of cracking catalyst fines

Abstract

Cracking catalyst fines that are separated from the cracked fluid leaving the cracking or separation zone of a catalytic cracker are not dropped back into the separation zone or cracker and thus are not left in the cracker-regenerator loop but rather are removed from this loop, e.g., by connecting the dip-leg of one or more of the cyclones in the cracker with a conduit guiding these fines to a location of disposal outside of the catalyst loop. In one embodiment, these fines are introduced into another catalytic cracker or the separation vessel associated with a further catalytic cracker so that these fines ultimately occur in the bottoms product from a fractionator associated with this further cracker. By this process, the bottoms product of the main fractionator associated with the main cracker can be more efficiently utilized for the production of a carbon black feedstock because this bottoms product contains a very significantly reduced quantity of catalyst fines.

Claims11

Dependent claims

In a cracking process comprising

(a) contacting a hydrocarbon feedstream and a cracking catalyst under cracking conditions in a cracking zone to produce a mixture of cracked hydrocarbon and cracking catalyst,
(b) separating said mixture in a separation zone into a cracking catalyst mass containing coke and a fluid mass consisting essentially of said cracked hydrocarbon and cracking catalyst fines,
(c) regenerating said cracking catalyst mass by contacting it with a free oxygen containing gas such as to combust at least a significant portion of said coke and to thereby produce a regenerated cracking catalyst mass,
(d) reintroducing said regenerated cracking catalyst mass into said cracking zone as at least part of said cracking catalyst moves in a loop from the cracking zone to the regeneration zone and back to the cracking zone,
(e) separating at least a significant portion of said cracking catalyst fines from said fluid mass,
the improvement comprising
(f) directly withdrawing and removing said so-separated cracking catalyst fines from said loop.

4 more elements

A twin-loop catalytic cracking process comprising

(a) a first catalytic cracker-regenerator loop operation including
(aa) contacting a first hydrocarbon feedstock and a cracking catalyst under cracking conditions in a first cracking zone to produce a first mixture of cracking catalyst and cracked hydrocarbons,
(bb) separating said first mixture in a first separation zone into a cracking catalyst mass containing coke and a fluid mass consisting essentially of said cracked hydrocarbon and cracking catalyst fines,
(cc) regenerating said cracking catalyst mass by contacting it with a free oxygen containing gas such as to combust at least a significant portion of said coke and to thereby produce a regenerated cracking catalyst mass in a first regeneration zone,
(dd) reintroducing said regenerated cracking catalyst mass into said first cracking zone as at least part of said cracking catalyst so that said cracking catalyst moves in a first loop from the first cracking zone to the first regeneration zone and back to the first cracking zone,
(b) separating at least a significant portion of said cracking catalyst fines from said fluid in a first catalyst fines separator,
(c) a second catalytic cracker-regenerator loop operation including contacting a hydrocarbon feedstock and a cracking catalyst under cracking conditions in a second cracking zone to produce a second mixture of cracking catalyst and cracked hydrocarbons, and regenerating said cracking catalyst in a second regeneration zone,
(d) directly withdrawing at least a significant portion of said cracking catalyst fines obtained from said first cracking catalyst fines separator from said first loop and
(e) introducing the so separated cracking catalyst fines into said second separation zone.

6 more elements

Dependencies are inferred from the claim text.

Removal of cracking catalyst fines

Life of this patent

Removal of cracking catalyst fines

Life of this patent

Abstract

Claims11