OP-II-3

PP-I-4A NEW APPROACH TO KINETIC STUDY OF PALLADIUM-CATALYZED SYNTHESIS OF VINYL ACETATE IN AHETEROGENEOUS GAS REACTION AND EFFECTS OF ALKALIMETALLIC ACETATE PROMOTERSArjmand M. 1 , Motahari K. 2 , Atashi H. 31 Royal Institute of Technology (KTH), Graduate School of Chemical Engineering,E-mail: arjmand@kth.se2 Arak University, Department of Chemical Engineering, Arak, Iran3 Zahedan University, Department of Chemical Engineering, Zahedan, Iran1. IntroductionVinyl acetate (VA) has been commercially prepared from ethylene (C 2 H 4 ), aceticacid (AcOH) and oxygen. The ideal reaction pathway is1C2H4+ CH3COOH+ O2→ C2H3OOCCH3+ H2O2So far various experimental investigation into finding the reaction kinetics [1-3] andmechanism have been carried out. However the work on analysis and study of promoterson this case is still limited. Herein, by injection of different promoters, we will be able todetermine the surface reaction parameters as well as most effective result.2. ExperimentalAll experiments were performed using a plug flow system. A reactor consisting ofa 1.5in inner diameter (ID) and 30cm length filled with Pd/SiO 2 catalyst of a diameterof 5mm and dispersion of 600 m 2 /gr was used at a pressure of 0.9 MPa and atemperature of 413-433 K. C 2 H 4 is saturated with Acetic acid and then evaporatedusing a heater. The saturated gas will then be superheated and then combined withO 2 and N 2 . Oxygen gas will be added on a concentration of less than %7 onmolecular basis in order to avoid an explosive reaction between ethylene andoxygen. The mixture leaving the reactor is condensed in two to three stages to obtainvinyl acetate in liquid phase and so prepared for analysis. A schematic diagram ofthe process is shown in Fig.1.Metallic promoters with assessed compound percentages are injected into thereactor by a micro pump. The inlet and outlet of the reactor is connected to a gaschromatograph; continuously determining the compound percentage of the enteringand exiting materials of the reactor. The experiments are performed for lithium,sodium, potassium, rubidium and caesium acetate salts.225