Advanced Reaction-Terminating Technique for FCC Riser Reactor

Numerical simulation of the performance of a commercial FCC riser reactor was carried out by using a three-dimensional gas-particle, two-phase, turbulent flow-reaction model. Results showed that overcracking of desired products, such as diesel or light fuel oil, occurs and the optimum yields of desirable FCC products could be achieved at a critical riser height of less than 20 m above the feed inlet. This suggests that injection of quenching media above the critical riser height can be an effective option for optimizing the yields of desirable products. The reaction-terminating technique conducted in a commercial FCC riser reactor, using light waste oil, straight-run gasoline, and desalted water as quenching media produced favorable results. Light fuel oil yields increased by 1.3 wt% and 0.95 wt% for using the first two quenching media. Liquefied cracking gas yields increased by 0.43 wt% and 1.03 wt%, whereas the yields of dry gas and coke decreased slightly. Desalted water produced better results than either light waste oil or straight-run gasoline. The improvements of gasoline and liquefied gas yields using desalted water are 0.95% and 0.49% more than those of using straight-run gasoline, respectively.