Non-thermal plasma assisted catalytic thiophene removal from fuel under different atmospheres

Abstract

Hydrodesulfurization is one of the most critical processes in the petroleum industry to increase the quality and economic value of crude oil. However, this process consumes a great amount of expensive hydrogen to convert sulfur-species to H2S, which causes a series of critical environmental issues. Herein, we report a novel method of non-thermal plasma assisted catalytic desulfurization of crude oil, while commonly used hydrogen is replaced with low-priced methane. As one of the most common sulfur-containing species in petroleum, thiophene is selected as the model compound in this study. It is proved that non-thermal plasma could effectively convert thiophene with a conversion higher than 90%, while thiophene is mostly converted into the solid deposit. Also, the H2S emission is well-controlled over a carefully designed Sn–Ga/SBA-15 catalyst. In a 12 h long-term experiment, the reactor still exhibits excellent desulfurization performance and low H2S emission during the whole test. Several control experiments are performed under N2 or H2 for comparison. Among all these atmospheres, N2 shows the best performance in terms of thiophene conversion and H2S emission minimization. The effect of CH4 and H2 incorporation is also investigated. As the product with the highest proportion, the composition of solid deposit is carefully analyzed, and a novel method of O2-plasma oxidation is tested to in-situ remove solid deposit over catalyst surface and reactor. In general, this research explores an economical and environmental-friendly alternative for the desulfurization of crude oil.