Oxidation of Ethene in a Wall-cooled Packed- Bed Reactor
ثبت نشده
چکیده
Abstract--The selective oxidation of ethene over a silver on cx-alumina catalyst was studied in a pilot plant with a wall-cooled tubular packed bed reactor. Gas and solid temperatures in the catalyst bed were measured at different axial and radial positions as well as concentrations at different axial position. Total pressure, inlet mole fraction ethene, mass flow rate and wall temperature were varied_ The experiments are compared with model calculations. A pseudo-homogeneous model and a heterogeneous two-dimensional model were used for the calculations. Kinetics and heat transport parameters in the model have been determined independently in separate studies_ The work is distinctive in the accuracy paid to a large number of experimental details. The models correspond reasonably well with the experiments at all operating conditions. The main problem in the description of the reactor is the inability of the kinetic expressions to predict the reaction rates over the entire range of partial pressures. As a result some systematic deviations are found, in particular in the predicted temperature profiles. The heterogeneous model gives better agreement with the experiments although systematically larger temperature differences are calculated on the basis of available correlations in literature than has been measured. On the basis of this work it is difficult to determine directly whether an influence of chemical reaction is present on the values of the heat transport parameters.
منابع مشابه
The Statistical Character of Packed-bed Heat Transport Properties
Packed beds are essentially heterogeneous on a pellet scale. For random packed beds this heterogeneity causes a statistical character both on a pellet and bed scale. We discuss experimental results which deal with bed-scale statistics. For packed beds on a laboratory scale, the results indicate that the beclscale statistical behaviour introduces a spread up to a factor of three in correlations ...
متن کاملAngular Temperature Variations in a Wall-Cooled
The signijkance of the statistical character of wall-cooled packed-bed reactors was studied by measuring angular temperature variations, which result @om the random nature of the packing. These are neglected in present-day mathematical models designed to describe the reactor behavior. The amplitude of these variations was determined experimentally as a function of the mass flux and the position...
متن کاملCitronellyl Butyrate Synthesis in Non-Conventional Media Using Packed-Bed Immobilized Candida Rugosa Lipase Reactor
The synthesis of citronellyl butyrate by direct esterification reaction catalyzed by immobilized lipase from Candida rugosa was studied in a continuous packed bed reactor using n-hexane as organic solvent. Parameters such as residence time, temperature, and pH were examined. The optimum conversion was obtained at a flow rate of 1 ml/min (residence time 8 min), temperature of 50 °C, and pH 7.5. ...
متن کاملA scalable silicon microreactor for preferential CO oxidation: performance comparison with a tubular packed-bed microreactor
PEM fuel cells utilizing hydrogen and oxygen have shown great promise as future sources of clean, efficient power. Due to difficulties encountered in hydrogen storage and transport, investigation of on-board generation of hydrogen via fuel processing of liquid hydrocarbons has gained prominence. To achieve these goals, the need for compact reactor systems with effective component and heat integ...
متن کامل