CRACKING DESULFURIZATION OF SULFIDES OVER FCC CATALYST

The cracking desulfurizations of mercapten, thioether, thiophene, 2-methyl-thiophene, 3-methyl-thiophene and benzothiophene over FCC catalyst were investigated under the conditions of 500 ℃ and catalyst to oil ratio of 2.4. Among these sulfides, mercapten and thioether are easily desulfurized with cracking method, and the sulfur removal rates of them are about 95 percent. Thiophene and benzothiophene are more difficult to be desulfurized, and the sulfur removal rates of them are about 65 percent. Thioether is more easily desulfurized than 2-methl-thiophene and has lower desulfurization rate than thiophene and benzothiophene. Benzothiophene is easy to produce sulfur-contained coke, and other sulfides are relatively difficult. The produced rate of sulfur-containing coke is only 7 percent. Furthermore, in the desulfurization process of thiophene over the FCC catalyst, methyl-thiopehes, 2-methyl-thiophenes, 3-methyl-thioiphenes and benzothiophene can produce sulfur-containing coke. Mercapten, thioether and benzothiophene cannot be converted into other sulfides under the experimental conditions. Thioether and methyl-thiophene can be converted with each other.