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  • Kinetic study of ethanol de...
    Carotenuto, G.; Tesser, R.; Di Serio, M.; Santacesaria, E.

    Catalysis today, 03/2013, Letnik: 203
    Journal Article, Conference Proceeding

    Display omitted ► A kinetic study of the ethanol dehydrogenation to ethyl acetate. ► Cu/CuCr2O4 as catalyst supported on Al2O3 promoted with BaO–Cr2O3. ► A Langmuir–Hinshelwood–Hougen–Watson kinetic model resulted the best to interpret all the performed kinetic runs. ► A reliable mechanism is suggested and discussed. A kinetic study of the ethanol dehydrogenation to ethyl acetate on a copper/copper-chromite catalyst has been performed. The used catalyst, in cylindrical pellets, contained also alumina as a support and barium chromate as a promoter. Support and promoter have the effect of increasing the activity, the selectivity and the stability of the catalyst, as shown in a previous work. The kinetic runs were carried out in a packed bed tubular reactor, alternatively filled with 2 or 50g of catalyst, approximately isothermal, by feeding pure ethanol together with a mixture of nitrogen and hydrogen as carrier gas. Kinetic runs have been made by changing the temperature, in the range of 200–260°C, the pressure between 10 and 30bar and the space time from 1 to 100ghmol−1. We have verified, at first, that inter-phase and intra-phase mass transfer limitations were negligible in the adopted conditions. Then, a Langmuir–Hinshelwood–Hougen–Watson kinetic model has been used for interpreting all the experimental data collected. This model corresponds to a mechanism in which the first step is the dissociative adsorption of ethanol on the surface, giving an adsorbed ethoxy group. Then, two other consecutive steps give place to respectively acetaldehyde as intermediate and ethyl acetate. This kinetic model allows a satisfactory fitting of all the performed experimental runs with a standard error below 15% for the runs performed with 2g of catalyst and less than 12% for the runs made with 50g of catalyst.