Polyaromatic sulfur compounds, hydrodesulfurization

Present State of the Art and Future Challenges in the Hydrodesulfurization of Polyaromatic Sulfur Compounds... 

Whitehurst, D.D., Isoda, T., and Mochida, I. Present state of the art and future challenges in the hydrodesulfurization of polyaromatic sulfur compounds. Advances in Catalysis, 1998, 42, 345. 

D. D. Whitehurst, T. Isoda, and I. Mochida, Present State of the Art and Future Challenges in the Hydrodesulfurization of Polyaromatic Sulfur Compounds, Advances in Catalysis 42 345 -71 (1998). 

Organic sulphur- and nitrogen-compounds in motor fuels are a source for acid rain and harmful to the environment. Moreover, they are poisonous to the auto exhaust catalysts. To meet new developments in EU regulations on the S-concentration, a commonly applied one-step hydrodesulfurization (HDS), using conventional catalysts, e.g. C0-M0/7-AI2O3, is insufficient. A second HDS step, viz. a deep HDS step, can be more economical to reduce the S-content to the currently allowed European level of 350 ppm. This level will be reduced further to 50 ppm in 2005 [1]. In the first HDS step, often the heavy organic sulfur-containing polyaromatics survived, such as dibenzothiophene (DBT) and (4-, and/or 6-) alkylated DBTs [2,3]. They are the most refractory. In crude oils, there are also aromatic N-compounds, which suppress the performance of the HDS catalysts. Hence, a model feed for representative HDS-activity measurements should contain characteristic S- and N- compounds for practical relevance. 

Kabe, T., IshUiaram A. and Tajima, H. Hydrodesulfurization of SuUur-Containing Polyaromatic Compounds in Light Oil. Irid. Eng. Chem. Res., 1992, 31,1577-1580. Tajima, H., Kabe, T., and IshUiaram A. Separation and Analysis of Sulfur-Containing Polyaromatic Hydrocarbons in Light Oil. Bunseki Kagaku, 1993, 42, 6775. 

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