Patent ID: 9657233
Date: 2017-05-23
CPC Classifications: B01J,C10G,Y02P

Claim:
1. Process for the fluidized-bed catalytic cracking of a weakly coking feedstock having a Conradson carbon residue equal to or less than 0.1% by weight and a hydrogen content equal to or greater than 12.7% by weight, comprising at least a step of cracking the feedstock in the presence of a catalyst, a step of separating/stripping effluents from coked catalyst particles, a step of regenerating said particles by partial or complete combustion of coke, and a step of recycling, before regeneration, at least one coking, carbonaceous and/or hydrocarbonaceous effluent, the process being characterized in that the amount of coking effluent injected into the coked catalyst is adjusted so as to deliver an additional amount of coke Qr to the catalyst and to satisfy the following equation (I): in which Qi is an initial coke content of the coked catalyst after the feedstock has been cracked and Qt or delta coke is a coke content that has been burned by partial or complete combustion, necessary for maintaining the heat balance of the process and for maintaining the temperature of a regenerated catalyst at a temperature equal to or greater than 690° C., said coking effluent having a content of aromatic compounds of greater than 50% by weight and comprising 20% by weight or more of polyaromatic compounds, and the process being characterized in that said coking effluent is recycled to at least one recycle zone in which a dense phase of coked catalyst from the stripping step is homogenized by inserting at least one structured packing element located upstream of the dispersing of said recycled coking effluent relative to the stream of catalyst particles and covering all or part of the cross section of said stripping zone and over at least a portion of the height thereof.