III International Conference

PP-III-78STUDY OF CATALYTIC OXIDATION PROCESSES OF CARBONIC COMPOUNDSOstroushko A.A., Sennikov M.Yu., Tonkushina M.O., Suslov E.A.Ural State University, Institute of Physics and Applied Mathematics, Yekaterinburg, RussiaE-mail: Alexandre.Ostroushko@usu.ruTheoretical modeling of catalytic oxidation of carbon particles is carried out. Processes ofsoot and CO oxidation on Cs x La 1-x VO 4 and M x La 1-x MnO 3 are experimentally investigated. Isshown promoter action of phases Al 2 O 3 and MnAl 2 O 4 in oxidizing reaction CO on perovskitesM x La 1-x MnO 3 .Complex oxides have high catalytic activity in oxidizing reactions of organic compounds,CO, soot. For protection of atmosphere against toxic exhausts it is necessary to oxidationsolids and light-end products.One of important conclusions, obtained during the study of kinetic peculiarities ofcarbonaceous materials oxidation on complex oxide catalysts, is the possibility of two kind ofcatalytic effect on a heterogeneous reaction: contact and remote. On the one hand, catalyst canaccelerate the process of oxidation of carbon up to СО, on the other hand – oxidation СО upto СО 2 . The first process is accelerated immediately in contact area of catalyst and a carbonparticle. Due to an essential exothermic of the second process the temperature combustionfront appears, which propagates on considerable distance from a contact surface. It results in araise of a total velocity of oxidation process and a change of a particle form.The theoretical model describing the process of carbon particles oxidation on a surface ofcatalyst is built. The model takes into account a velocity of level-by-level burning of aparticle, remote action of catalyst and a modification of particle geometry during burning. Weselected two basic alternatives as models, when the form of carbonaceous particles is close tocylindrical or spherical. For example, we supposed that the part of a cylindrical particlecontacting with catalyst during oxidation takes a shape of a truncated cone. Eventually thearea of surface, subject to non-contact oxidation is increased. Various interrelations ofefficient kinetic constants of level-by-level burning (H) and non-contact oxidation (C) wereaccepted for model calculations. In fact, the modification of the interrelations mentionedabove can actually occur as a result of temperature change and in dependence on nature ofcatalyst also. One can expect that at rather low temperatures, the velocity of process of contactoxidation is higher, and at relatively high temperatures, the second process dominates. Whenthe kinetic constant of remote oxidation is much less, than constant of contact burning andthere are no difficulties in transfer of an oxidant and reaction products, the process of linearoxidation of carbon particles (a mass loss) can be realized. The designed program allows616