Naphtha Deep Catalytic Cracking Process Developed by CAS Dalian Institute of Chemical Physics

The CAS Dalian Institute of Chemical Physics (DICP)has developed a process for conversion of naphtha feed, which is characteristic of adjustable proportion of products (including low‐carbon olefins, light aromatic hydrocarbons and high quality gasoline).The specific process is as follows: Firstly, the raw material is in contact with the catalyst in a riser reactor prior to entering a fluidized bed reactor, and the product gas I and catalyst with pre-deposited coke are separated at the expanded section of the fluidized bed reactor.Then the catalyst with pre‐deposited coke runs down to the reaction section of the fluidized bed reactor, in which it reacts with the feedstock that comes from the bottom to obtain the product gas II, and the spent catalyst is routed back to the riser reactor after being regenerated.This process can improve the plant ability to adjust the naphtha catalytic cracking products (covering 42%‒72% of olefin yield,16%‒24% of aromatics yield, and 6%‒21% of gasoline yield), thus improving the ability of the process unit to cope with the market fluctuations.

In an embodiment example, under conditions covering a riser reactor temperature of 680 ℃, a reaction pressure of 0.01 MPa (gauge), and a riser gas‐phase linear velocity of 3 m/sec; a fluidized bed reaction temperature of 670 ℃,a reaction pressure of 0.01 MPa (gauge), a gas‐phase linear velocity of 1.0 m/sec, a feed naphtha/methanol mass ratio of 0.5 in the fluidized reactor, and a feed mass ratio between riser reactor and fluidized reactor of 1:9, the yield of olefins is 72%, and the yield of aromatics is 16%, with the yield of high‐quality gasoline equating to 6%.