OP-II-3

PP-I-13RRHOHOHOTiOOOHHO HOH CCHC C 3+3HOH 3 CCH 3HOTiOOHHHOHOCCOHOHBesides, it was experimentally confirmed that the formed propylene oxide inhibitsthe epoxidation process. Apparently, this is due to the fact that propylene oxide alsoadsorbs on the active centers of the catalyst, thereby reducing the proportion of thefree surface and the possibility of formation of five-membered complex. Therefore theconcentration of propylene oxide should be considered in the kinetic equation.Thus, in the process of epoxidation can be nominally detailed the followingstages: adsorption of hydrogen peroxide, the superficial reaction and desorption ofpropylene oxide. And each of these stages can be limiting. Studying the influence ofvarious factors on the process, we have established that there is observed increaseof epoxidation process rate at increas concentrations of propylene and hydrogenperoxide. Based on it we can conclude that the adsorption stage of hydrogenperoxide is not limitingTo receive the kinetic model we have made the assumptions that the rate-limitingstep of the process of liquid-phase epoxidation of propylene by hydrogen peroxide atheterogeneous catalysts is the superficial reaction, at that all of the adsorbedcomponents are in equilibrium; reaction takes place between hydrogen peroxideadsorbed on the surface of the catalyst and propylene located in the dissolved state.According to these assumptions we have received the following kinetic model:kr =1+K1H2O2⋅KH O⋅[H2O2] ⋅[C3H6]2 2⋅[HO ] + K ⋅[CH O]22C3H6OThe experimental data were processed by the method of nonlinear LS (leastsquares). As the result, we calculated the values of parametres of the kineticequation providing an adequate description of all experiments that were carryed out.36244