79
However, processes like Superflex, ACO, etc., are developed to convert lowvalue naphtha feedstock to light olefins by employing ZSM-5 zeolite-based catalyst
at very high reaction severity. Since these light feedstocks make very less catalytic
coke, these processes require external heat supply to satisfy the heat demand for the
endothermic cracking reaction in the riser [47].
4.6 Catalyst Deactivation and Coke Formation
There are two mechanisms by which a particulate catalyst deactivates: physical and
chemical. Physical phenomena are sintering at high temperature, malocclusion, and
loss of surface area due to attrition [36].
The chemical mechanisms are more prevalent and can be subdivided into three
categories:
• Loss of acidity of the catalyst due to reactions with alkaline metals or basic
nitrogenous entities.
Fig. 10 Main fractionator [31]
Recent Developments in FCC Process and Catalysts
However, processes like Superflex, ACO, etc., are developed to convert lowvalue naphtha feedstock to light olefins by employing ZSM-5 zeolite-based catalyst
at very high reaction severity. Since these light feedstocks make very less catalytic
coke, these processes require external heat supply to satisfy the heat demand for the
endothermic cracking reaction in the riser [47].
4.6 Catalyst Deactivation and Coke Formation
There are two mechanisms by which a particulate catalyst deactivates: physical and
chemical. Physical phenomena are sintering at high temperature, malocclusion, and
loss of surface area due to attrition [36].
The chemical mechanisms are more prevalent and can be subdivided into three
categories:
• Loss of acidity of the catalyst due to reactions with alkaline metals or basic
nitrogenous entities.
Fig. 10 Main fractionator [31]
Recent Developments in FCC Process and Catalysts