Abstract: The catalyst regeneration process running under the partial oxidation mode in traditional fluid catalytic cracking (FCC) units needs a carbon monoxide (CO) boiler to burn the flue gas, resulting in a large volume of CO2 emissions. In this study, the performance of a set of industrial serial-type FCC regenerators and the changes in flue gas composition were analyzed by establishing a model of the regenerators and the flue gas energy recovery section. Considering the value of utilizing CO, based on the simulation, this paper proposes two schemes for maximizing CO content in the flue gas of regenerators. The two sets of optimal process operating parameters were obtained using a genetic algorithm. Compared with the original process, the CO contents of flue gas in the two optimized processes increased to 6.6% and 12.5%, CO2 emissions were reduced by 48.4% and 96.7%, and the costs of CO production were 0.57 $/Nm3 and 0.84 $/Nm3, respectively.

Key words: FCC regenerators, Rigorous process simulation, CO production, CO2 utilization