An improved fluid catalytic cracking unit(FCCU)riser-regenerator model combined with carbon-monoxide(CO)combustion was proposed,since multiple steady states of FCCU would change as CO conversion changed with different amounts of CO combustion promoter added.Due to the conservative consumption of CO combustion promoter which contains Pt as the active component in refineries,the amount of the added combustion promoter would significantly affect the economics.Thus,based on the heat balance of the high-efficien...