Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-III-18DEVELOPMENT OF INDUSTRIAL CATALYST SELECTIVITY INTHE HYDROGENATION PROCESS OF DIENES С 9 –С 14Egor M. Yuriev, Elena N. Ivashkina, E.D. Ivanchina, A. KolupaevTomsk Polytechnic University, 634050, Lenin Street, 30, Tomsk, Russia;fax: +7(3822)563-435; e-mail: emyu@anchem.chtd.tpu.ru, emyu@sibmail.comTraditionally increase of catalyst efficiency for the oil refining processes requireslaboratory and pilot research. The ways of Ni-catalyst development which we propose arebased on a calculation with use of a mathematical model for higher diolefines hydrogenationprocess.For the most part diolefines are hydrogenated to olefins, which, in their turn, can behydrogenated to paraffins and thus the process selectivity and the yield of desired product arereduced.The main peculiarity of this process is a selective catalyst poisoning with a sulfur-bearingsubstance in order to raise catalyst selectivity.The mathematical model of hydrogenation process is based on a scheme of chemicaltransformations. Sulfur-bearing substance (DMDS) takes part in the following reactions:CH −S −S − CH + 1.5H + 1.5Ni → 1.5NiS + 2CH + 0.5H S3 3 2 4 2Ni+ H2S → NiS+H2(2)Reaction (2) leads to desorption of Ni from catalyst surface. In the presence of water thedeactivation of catalyst is very probable:NiS + H2O → NiO + H2S(3)Thermodynamic analysis shows that reaction (1) is irreversible, and so quantity ofpoisoning substance on the catalyst surface depends on the reaction (2) equilibrium. Catalystactivity reduces as a result of this reaction. Quantity of sulphide, in its turn, increases with therise of sulfur-bearing substance consumption, with rise of equilibrium constant (2) anddecrease of hydrogen quantity in the system.As the dependences of hydrogenation reaction rate on the catalyst activity are different forolefins and diolefines, the determination of optimal catalytic activity is rather complexproblem.The following dependence of the DMDS residual quantity on the temperature in reactorwas discovered while analyzing experimental data (Fig. 1).(1)337