Abstract: Based on the conventional processing flow where fluid catalytic cracking (FCC) wet gas and naphtha are first separated into dry gas, liquefied petroleum gas (LPG), and stabilized gasoline via the absorption-stabilization unit, followed by separate desulfurization. The dry gas is then treated with the alcohol amine method to remove hydrogen sulfide, while the LPG undergoes both the alcohol amine method for hydrogen sulfide removal and catalytic oxidation for mercaptan removal. The stabilized gasoline employs S Zorb adsorptive desulfurization technology to eliminate mercaptans, sulfides, and thiophenic sulfur compounds. A "reverse order" integrated technology was proposed, where FCC wet gas and naphtha first undergo integrated adsorptive desulfurization in two independent reactors, followed by a process similar to FCC absorption-stabilization separation flow, yielding refined dry gas, refined LPG, and refined gasoline. This "reverse order" integrated technology fully leverages the advantages of S Zorb's high desulfurization efficiency, low comprehensive energy consumption, and the high separation precision and mature technology of FCC absorption-stabilization unit. It enhances desulfurization efficiency, simplifies the production process, improves the separation precision and yield of refined gasoline, and reduces octane loss. After adopting the "reverse order" integrated technology, the refined gasoline yield increased by 0.9 percentage point, research octane number rose by 0.6, and the company's economic benefits improved obviously.

Key words: catalytic cracking, wet gas, naphtha, separation, desulfurization, reverse-order, energy conservation and consumption reduction