Abstract: The full process simulation of the 2 Mt/a catalytic cracking unit's fractionation and absorption-stabilization system at a certain refinery was conducted using Aspen Plus, and the process parameters of the distillation and absorption-stabilization system were optimized using sensitivity analysis methods. In the distillation system, by adjusting the top circulation and the first middle circulation, the quality of gasoline and diesel was improved, while the high-temperature heat extraction ratio increased by 5.26 percentage points, which can be used to generate high-temperature steam; in the absorption-stabilization system, the focus was on examining the impact of the feed position of the crude gasoline in the absorption tower, the liquid-gas ratio in the absorption tower, the return position of the rich absorption oil to the distillation tower, the feed position of the stabilization tower, and the reflux ratio on product quality. Through parameter simulation optimization, the product quality was significantly improved. Specifically, the volume fraction of C₃+ in dry gasdecreased by 54.3%, the volume fraction of (C₂+C₅)in liquefied gasdecreased by 7.5%, and the mass fraction of (C₃+C₄)in stabilized gasoline decreased by 43.2%.

Key words: catalytic cracking, fractionation and absorption-stabilization system, sensitivity analysis, simulation, optimization