from first principles PP-I-1

PP-II-14Kinetic Schemes Evaluation for Homogeneous Ethane and PropaneDehydrogenationSnytnikov V.N. 1 , Mischenko T.I. 1 , Stoyanovskaya O.P. 1 , Yunusov A. 2 , Gubaidullin I.M. 31 Boreskov Institute of Catalysis, Novosibirsk, Russia2 Bashkir State University, Ufa, Russia3 Institute of Petrochemistry and Catalysis, Ufa, RussiaWe studied mechanisms of homogeneous ethane and propane dehydrogenation underconditions of a wall - less reactor described in the articles [1-3]. The continuous CO 2 - laserwas used as an energy source in this reactor. Since ethane and propane does not absorbradiation of the CO 2 laser, it was mixed with ethylene or propylene which are characterizedby a strong absorption band at 10.6 μm. The product analysis was made usingchromatographic technique.Propylene was formed in amount of 1–1.5 vol % under any conditions of the ethane pyrolysis.Acetylene was detected at high conversions of ethane. No other product was detected.The main products of the propane dehydrogenation in tube furnaces are methane, ethylene,hydrogen and propylene. Ethane, acetylene, butane, butene, divinyl are registered in smallerquantity. The products composition of propane dehydrogenation was founded to be similar tothe one obtained in the pyrolysis furnaces.Kinetic model was constructed for the proposed reaction scheme. Because of experimentconditions (high temperatures), the process is described by system of stiff ordinarydifferential equations, so AL-stable implicit Runge-Kutta methods were used for solvingODEs. To find the constants we used the approach of inverse problems of chemical kinetics.Using genetics algorithms, the constants were found, and confidence intervals of the constantstoo. Found schemes represent autocatalytic mechanism of the propane and ethane pyrolysis,which has an autocatalytic route with respect to ethylene.[1] V.N. Snytnikov, T.I. Mishchenko, Vl.N. Snytnikov, O.P. Stoyanovskaya, V.N. Parmon. Kineticsand Catalysis. 51 (2010), 1, 10 – 17.[2] V. N. Snytnikov, T.I. Mishchenko, Vl.N. Snytnikov, S.E. Malykhin, V.I. Avdeev, V. N. Parmon.Research on Chemical Intermediates: 38 (2012), 3, 1133 - 1147.[3] V.N. Snytnikov, T.I. Mischenko, Vl.N. Snytnikov, I.G. Chernykh. Chemical Engineering Journal.150 (2009), 231 - 236.145