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PP-II-57MATHEMATICAL MODELING OF BENZENE HYDROGENATION INTHE THIOPHENE PRESENCE UNDER PERIODIC OPERATIONReshetnikov S.I. 1 , Pyatnitsky Yu.I. 2 , Ivanov E.A. 1 , Dolgykh L.Yu. 21 Boreskov Institute of Catalysis SB RAS, Pr. Akademika Lavrentieva 5,Novosibirsk, 630090, Russia, E-mail: reshet@catalysis.nsk.su2 Pisarzhevsky Institute of Physical Chemistry NASU, Prospekt Nauky, 31,Kiev, Ukraine; ldolgykh@inphyschem-nas.kiev.uaOne of the important subjects of environmental catalysis is research on cleanfuels [1,2]. In the past decade, some areas of the research on clean fuels includedhydrodearomatization (HDA) and hydrodesulfurization (HDS), which proceed onsulfide (Ni,Mo) and (Ni, W) catalysts. The new Environmental Protection Agency(EPA) regulations reduce the sulfur content of the highway diesel fuel from500 ppmw (1989) up to 15 ppmw (June 2006). In this case, the volume of catalystbed will have to be increased 3.2 times as that of the current HDS catalyst bed [2].Therefore, new catalysts and processes of fuels treatment are necessary. As it is wellknown, a difficult problem of the HDA–HDS processes on sulfide catalysts is themutual inhibition of hydrogenation reactions by sulfur–organic compounds and ofhydrogenolysis reactions by aromatics.At the same time, experimental and theoretical studies in heterogeneouscatalysis during the last decades have given evidence that reactor performanceunder unsteady state conditions can lead to improved process efficiency compared tosteady state operation. Under transient conditions, it is possible to maintain thecatalyst surface in an optimal state increasing the average reaction rate andselectivity towards a specific product resulting in an enhanced reactor performance.One of the ways to attain the catalyst unsteady state is forced oscillations of thereactant concentrations (periodic reactor operations) [3,4].The HDA–HDS problem in this work was studied on the example of benzenehydrogenation and thiophene hydrogenolysis:C 6 H 6 +3H 2 = C 6 H 12(benzene hydrogenation), HDA,C 4 H 4 S + 4H 2 = H 2 S + C 4 H 10 (thiophene hydrogenolysis), HDSThe goal of this work is mathematical modeling of benzene hydrogenation intocyclogehane in the thiophene presence over the sulfide Ni-Mo/γ-AL 2 O 3 catalyst underperiodic operation.437