Photochemical Oxidation of Thiophene by O 2 in an Oil/Acetonitrile Two‐Phase Extraction System

Photochemical oxidation of thiophene in an n ‐octane/acetonitrile extraction system using O 2 as oxidant was studied. Results obtained here can be used as a reference for desulfurization of gasoline, because thiophene is one of the main components containing sulfur in fluid catalytic cracking gasoline. A 500‐W high‐pressure mercury lamp was used as a light source for irradiation, and air was introduced by a gas pump to supply O 2 . Thiophene dissolved in nopolar n ‐octane solvent was photodecomposed and removed into the polar acetonitrile phase. The desulfurization rate of thiophene in n ‐octane was 65.2% under photoirradiation for 5 h under the conditions of air flow at 150 mL min −1 , and V( n ‐octane):V(acetonitrile) = 1:1. This can be improved to 96.5% by adding 0.15 g Na‐ZSM‐5 zeolite into the 100‐mL reaction system, which is the absorbent for O 2 and thiophene. Under such conditions, the photooxidation kinetics of thiophene with O 2 and Na‐ZSM‐5 zeolite is first‐order with an apparent rate constant of 0.6297 h −1 and half‐time of 1.10 h. The sulfur content can be reduced from 800 μL L −1 to 28 μL L −1 .