ABSTRACT
Deep desulfurization of petroleum products with the least severity is desired to protect the environment (1,2,3,4). CoMo catalyst has conventionally been applied in the hydrodesulfurization of gas oil to remove sulfur in products, since under conventional hydrodesulfurization (HDS) processing of gas oil it shows slightly higher catalytic activity for HDS and less hydrogen consumption than NiMo catalyst. The latter catalyst is more commonly applied in hydro genation and hydrodenitrogenation because of its higher hydrogenation activ ity than the former (5,6,7). Consequently, relatively less attention has been paid to the HDS of gas oil than NiMo catalysts (8).
