The flow

heat transfer and reaction behaviors in the fluid catalytic cracking (FCC) riser before and after the injection of terminator were simulated by the computational fluid dynamics (CFD) method. Distributions of velocity

solid catalyst volume fraction

temperature

and species concentration in FCC riser were obtained after the injection of terminator. Besides

the action zone of the terminator and the effect on cracking reactions were analyzed with different mass fraction and teeming height of the terminator. The simulation results showed that with injection of the terminator

the velocity of oil gas was increased but volume fraction and temperature of the catalyst as well as temperature of the oil gas were decreased. The change in flow and the heat transfer caused the reduction in degree of the cracking reactions and the secondary reaction of oil gas in the riser

which resulted in a higher yield of gasoline and lower yields of dry gas

LPG and coke. The action zone and the effect on cracking reaction varied with different mass fraction and teeming height of the terminator

which should be evaluated by actual process conditions.