OP-II-3

PP-I-57In the studied range of temperatures formation rates of all products are increasedwith growth of n-butane partial pressure. Influence of hydrogen partial pressure onreactions rates depends on temperature: at 473 K negative order on hydrogen isobserved which with increasing of temperature is approached to zeroth one.Therefore, dependences of formation rates of n-butane conversion products onpartial pressures of reactants are described by one total equation:Wn mi = kiPPn−CH H(1)Reaction orders n and m were determined from the slops of lines fitting rate vs.reactant partial pressures on logarithmic coordinates. It has been found, that for allreaction products and at different temperatures n has 1.3±0.2 value, at 473 K m isequal to -0.5±0.1 and with increasing of temperature is approached to zero. Apparentactivation energies calculated from Arrhenius plots of reaction rates for isobutane,isopentane and propane formation are equal to 72 ± 4; 102 ± 6 and 116 ± 6 kJ mole –1 ,respectively.Different kinetic models of the process were considered. It has been shown thatthe reaction has complex nature and it specific mechanism depends on both catalystnature and process operation conditions. Both monomolecular and bimolecularmechanism of reaction may be predominant with changing of temperature. As thereaction network is complex and the primary and secondary reactions not resolved,the kinetic results cannot be regarded as more than just empirical; they representoverall reactions and not a resolution of the individual reactions. Nevertheless, on thebasis of obtained results a search of the promoters, permitting to decrease anisomerization reaction temperature and to provide a higher selectivity, may beconsidered as the perspective approach to a development of the effective mordenitecatalysts for n-butane isomerization.References[1]. D.B. Tagiyev, R.V. Starikov, A.A. Imanova. Stud. Surf. Sci. Catal., 2005,158, 1685.[2]. D.B. Tagiyev, R.V. Starikov, A.A. Imanova, M.I. Rustamov. Petroleum Chemistry, 2008, 48, 29.4102321