The Continuous Desulfurization of FCC Gasoline through Extraction and Photocatalysis-oxidation

Abstract

Removal of sulfur-containing compounds from gasoline, based on the combination of various technologies (liquid-liquid extraction and extraction- photocatalysis-oxidation desulfurization) using a biphasic system (oil/acetonitrile) has been investigated. The effect of operation conditions on desulfurization rates and the distribution coefficient in a model system for gasoline were explored. Additionally, extraction-desulfurization kinetics are studied through simulation; the kinetics equation, (−rA) = 7.1cA 0.008, was obtained. Experimental results show that the proper extraction conditions are: diluents content, 0.01–0.05; solvent/oil ratio, 1.5–2.5; and extraction temperature, 30–50°C. A successive removal of these sulfur compounds is carried out through photoirradiating in the solvent phase to form highly polarized compounds from fuel oils with a solvent. The operation conditions include a temperature of 30–50°C, atmospheric pressure, and the ratio of oxidation agent/oil of 0.01–0.005 over our home-made catalyst. Sulfur contents in the fuel oils are reduced to less than 10 μg/g. In addition, the photocatalysis kinetics were worked out to be (−rA) = 0.4221cA – 12.01. On the basis of the above results, an integrated overall refining process for sulfur removal from fluid catalyst cracking gasoline has been developed.