A process for producing ultraclean gasoline by coupling efficient hydrodesulfurization and directional olefin conversion

To solve the contradiction between ultradeep hydrodesulfurization (HDS) and octane recovery in clean gasoline production, this article proposes a novel two-stage fluid catalytic cracking (FCC) gasoline hydro-upgrading process with the selective HDS catalyst in the first reactor and the complemental HDS and octane recovery catalyst in the second reactor. The process achieved the relayed removal of sulfur-containing compounds with different natures, providing itself with excellent HDS performance, and the hydroisomerization and aromatization of olefins in the second stage endowed the process with superior octane recovery ability and high product yield while remarkably reducing the olefin content of FCC gasoline. The process was also featured by low hydrogen consumption due to the low first-stage olefin saturation and the balanced second-stage hydrogenation and dehydrogenation. The two-stage process developed here sheds a light for efficiently producing ultralow sulfur gasoline from the poor-quality FCC gasoline of high olefin and sulfur contents. © 2012 American Institute of Chemical Engineers AIChE J, 59: 571–581, 2013