Abstract: It was found that the reduction of olefin and sulfur content in FCC gasoline would lead to a large loss of octane number and a sharp increase of production cost in the treatment of high-sulfur and high-olefin gasoline. The reason is that when the gasoline desulfurization ratio exceeds 97%, the olefin saturation rate will be increased sharply. In addition, it will also lead to an increase in hydrogen consumption and production cost. Therefore, a step-by-step integrated process for olefin reduction and desulfurization of FCC gasoline was established, and the olefin content reduction of FCC gasoline was realized by means of a catalytic cracking process consisting of a directional control of gasoline, which was enhanced by isomerization and selective hydrogen transfer reaction. The volume fraction of olefin and the mass fraction of sulfur in gasoline were reduced to less than 20% and 300 μg/g, respectively. The post-desulfurization process controls the desulfurization ratio of gasoline to be less than 97% and the olefin saturation ratio to be less than 20%, and the final octane number loss is greatly reduced, cleverly resolving the contradiction chain of desulfurization-olefin saturation-octane number loss-low cost production. The commercial application shows that the olefin saturation and octane number loss of the process are significantly reduced under the same desulfurization ratio, the low-cost production of China V and VI vehicle gasoline is realized, and it can provide strong support for the continuous upgrading of gasoline.

Key words: gasoline, desulfurization ratio, olefin saturation ratio, octane number reduction, ntegrated process