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

PP-I-27into propionic acid. The given results showed that with increasing of partial pressure ofn-propyl alcohol selectivity of process on propionic acid is increased at temperatures 453-498 K. The yield of propionic acid reaches maximal value (66.4%) at partial pressure ofn-propyl alcohol 10 kPa (T=498 K) and then yield of propionic acid begins to decrease. Thedecrease of yield of propionic acid can be explained in such way that at the given partialpressure of oxygen (P O2 =30 kPa) relatively high partial pressures of n-propyl alcohol preventto the coordination of oxygen to the active centers of metalzeolite catalyst. The increase ofpartial pressure of oxygen at temperatures T= 453-498 K results in the negligible increase ofselectivity of the process on propionic acid and increase the yield of propionic acid. The resultsof the carried out investigations have also shown that the greatest yield of propionic acid and thegreatest selectivity of the process on propionic acid are observed at relatively low space velocity(900 h -1 ) and reach to maximal value in the range of temperatures 488-498 K.On the basis of the experimental data the total kinetic scheme of oxidation reaction ofn-propyl alcohol over catalyst CuCaA can be depicted as:+4O 21 kC 3 H 7 OH + O 22 CH 3 CH 2 CHO2 -H O3CO 2 + 3H 2 O1+ Ok 12 , k2 3+CCH 3 CH 2 COOH3 H 7 OH-H OCH 3 CH 2 COOC 3 H 7where k 1 , k 2 , k 3 и k 4 – constants of the reaction rate of propylpropionate, propionic aldehyde,propionic acid and carbon dioxide.2On the basis of kinetic equations kinetic model of n-propyl alcohol oxidation process overzeolite catalyst CuCaA was presented and subjected to statistical analysis on the basis ofexperimental kinetic data. Kinetic parameters of the given model have been determined on thebasis of kinetic equations of n-propyl alcohol oxidation reaction into propionic acid by meansof comparison of experimental and calculated kinetic data.ConclusionsIt has been established that polyfunctional zeolite catalyst CuCaA containing 3.0 wt.%Cu 2+ shows the high activity and selectivity in the direct oxidation of n-propyl alcohol intopropionic acid. The kinetic regularities of the given reaction have been studied over catalystCuCaA. On the basis of experimental data kinetic scheme of n-propyl alcohol oxidationreaction has been proposed and kinetic model of the present process has been developed.References1. M.A. Wassel, N.Kh. Allahverdova, K.Y. Adjamov, Collect.Czechosl.Chem.Commun., 57 (1992) 446.2. L. Jinglin, L. Bin, L. Jiang and et al., J.Catal., 20 (1999) 429.k 42260