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The aim of this work was to investigate the performance of a cross-flow sandwich catalytic structure and to compare it with that of conventional random packings. The liquid-phase catalytic hydrogenation of Styrene to Ethylbenzene in n-Butanol solution was chosen as the test reaction. The intrinsic kinetics of the reaction was preliminarly investigated in a batch multiphase rotating basket reactor. The tests with the various kinds of catalytic packing were carried out in a tubular reactor (50 mm internal diameter) by recycling both the liquid and the gas phase. The results of this work show that mass transfer and hydrodynamic limiting effects in cross-flow structured packing are significantly lower than in a random bed of particles both in upflow and downflow concurrent regimes.

The catalytic oxidation of n -propanol in aqueous solution by gaseous oxygen was carried out in a packed-bed upflow reactor. Reaction rates were measured at different temperatures, liquid and gas superficial velocities, oxygen partial pressure and alcohol concentrations. The kind of rate controlling regime was identified by examining the influence of the operating conditions on the conversion rate. The experimental data were compared with reaction rates calculated by different reactor models. Single propanol solutions and mixtures with other aliphatic alcohols were tested to point out the interaction between the reactants and the influence of the liquid phase physical properties on the reactor performance. The results show a remarkable influence of the concentration of liquid phase reactants on propanol oxidation rate. A set of experimental runs was carried out using surfactant solutions to emphasize the surface tension effects.

We examined the conversion rate during the oxidation of ethanol in a trickle-bed reactor in a wide range of hydrodynamic conditions, temperatures and concentrations. The results have confirmed the findings of other authors that mass transfer of the gaseous reactant to the catalyst surface also takes place through zones of liquid which are not effective during a physical process. However, they have also shown an influence of the temperature and concentration of the volatile liquid reactant never reported before. This effect has been qualitatively explained by assuming that the supply of the ethanol to liquid zones with a poor renewal occurs mainly by an evaporation—condensation process. Accordingly, the data were well correlated by the ratio between the partial pressures of ethanol and oxygen in the gas phase.