Oxidative Desulfurization Of Model Diesel Over Ti-Containing Molecular Sieves Using Hydrogen Peroxide

Recently there has been much interest in the deep desulfurization of liquid hydrocarbon fuels as the environmental regulations become stricter. In the petroleum refining industry, catalytic hydrodesulfurization (HDS) is currently used for reducing the sulfur content of the liquid products. However, to achieve deep desulfurization goals with current HDS technology, high temperature, high pressure and large volume reactor are not avoidable. Therefore, oxidative desulfurization (ODS) as an alternative or complementary technology to HDS is a promising method.Oxidative desulfurization of diesel with hydrogen peroxide using molecular sieves as catalysts has several attractive features, such as low temperature, low pressure conditions and low cost of operation. Besides, the catalysts can be recovered. In this work, mesoporous Ti-HMS and mesoporous Ti-MSU were synthesized separately by using DDA and AEO9 as templates, TEOS as Si source and TBOT as Ti source. The characterization of the synthesized Ti-HMS and Ti-MSU was carried out by XRD, BET, FTIR and UV-Vis. The results showed that all samples synthesized possessed typical Ti-HMS and Ti-MSU characteristics.In this work, ODS of DBT with H₂O₂ using mesoporous Ti-HMS and Ti-MSU as catalysts was also studied. The effects of Si/Ti ratios and reaction conditions on the sulfur removal were investigated. The DBT conversion up to 80% could be obtained with Ti-HMS as catalyst by choosing suitable conditions. And the DBT conversion up to 58% could be obtained by using Ti-MSU as catalyst. The DBT was oxidized into sulfone in the reaction.