Deep hydrodesulfurization method for catalytic gasoline

The invention discloses a deep hydrodesulfurization method for catalytic gasoline. The method comprises: adjusting the operating conditions of a catalytic device fractionating tower, adding a lateral line, and adopting an appropriate cutting point to perform cutting so as to obtain light fractions at the tower top and heavy fractions at the lateral line; subjecting the light fractions to alkali-free deodorization, then passing the deodorized light fractions through a hydrogenation prefractionator to separate light gasoline and medium gasoline; and subjecting the separated medium gasoline and the heavy fractions to selective hydrogenation, and mixing the refined product with the light gasoline subjected to alkali-free deodorization, thus obtaining a clean gasoline product or a blending component. Compared with the existing catalytic gasoline hydrodesulfurization technologies, the method provided in the invention has the advantages that: the equipment energy consumption is significantly reduced, the gasoline octane number loss is small, the gasoline product quality can meet the quality requirement for a sulfur content of less than 10 micrograms/g, and the economic benefits of oil refining enterprises are improved.