The effect ofpartial internal wetting ofcatalyst pellets on apparent reaction kinetics at elevated temperatures and pressures is investigated experimentally and by modeling for benzene hydrogenation. A new method that combines adsorption and chemical reaction is introduced to study the kinetics influenced by capillary condensation ofreagents at steady-state conditions. It is shown that the extent ofliquid filling in the pellet interior has a critical effect on the global kinetics, and the current state of the catalyst depends on the history. Under certain conditions two steady states ofthe effectiveness factor exist. Moreover, either a decrease in temperature or increase in total pressure can increase the effectiveness factor. The model exhibits good agreement with experimental results.

The alkylation of benzene with ethylene over

The supercritical antisolvent (SAS) process has been used to produce submicronic Bronze Red particles. Among the process parameters, the pressure, temperature, and flow rate of the solution were studied. Two different solvents, ethanol and acetone, were also studied. The concentration of the liquid solution was kept unchanged in all of the experiments. The size and morphology of particles were affected by the temperature, pressure, and flow rate when ethanol was used as the solvent. Nevertheless, the size and morphology of the crystals precipitated from acetone were little sensitive to temperature and pressure but were influenced only by the flow rate. It was indicated that the interaction between the solute and the solvent played an important role in controlling the morphology and size of the crystals of Bronze Red under the same concentration.

Understanding the mechanism of liquid-phase evaporation in a three-phase fixed-bed reactor is of practical importance, because the reaction heat is usually 7-10 times the vaporization heat of the liquid components. Evaporation, especially the liquid dryout, can largely influence the reactor performance and even safety. To predict the vanishing condition of the liquid phase, Raoult's law was applied as a preliminary approach, with the liquid vanishing temperature defined based on a liquid flow rate of zero. While providing correct trends, Raoult's law exhibits some limitation in explaining the temperature profile in the reactor. To comprehensively understand the whole process of liquid evaporation, a set of experiments on inlet temperature, catalyst activity, liquid flow rate, gas flow rate, and operation pressure were carried out. A liquid-region length-predicting equation is suggested based on these experiments and the principle of heat balance.