抄録
Photochemical desulfurization of light oils of different sulfur contents and aromatic components, such as straight-run light gas oil (LGO) and light cycle oil (LCO), in an oil/hydrogen peroxide aqueous solution two-phase liquid-liquid extraction system is investigated. The entire wavelength region of light from a high-pressure mercury lamp was utilized to realize the direct excitation of sulfur-containing compounds. In the case of LGO of high sulfur content, 77% of the sulfur is removed by 36 h of photoirradiation, and the quantity of sulfur removed from LGO is six-fold greater than that in the case of commercial light oil (CLO). Although the desulfurization of LCO is suppressed by the presence of large quantity of 2-ring aromatics, the sulfur content is reduced to less than 0.05 wt% to meet with regulations in Japan. GC-AED analysis shows that benzothiophenes in all the feedstocks are more easily desulfurized than dibenzothiophenes. Highly substituted dibenzothiophenes in LCO, especially those having substituted carbon number of 4–6, are hardly desulfurized by the proposed method.
