Ethylene epoxidation with hydrogen peroxide was studied in a laboratory-scale trickle bed reactor under a broad range of experimental conditions (15–80 °C, 2.5–8.5 bar) utilizing a commercial titanium-silicate catalyst (TS-1). The catalyst was very stable and selective over 150 h time-on-stream. The main reaction product was ethylene oxide, while 2-methoxyethanol and ethylene glycol were observed as kinetic byproducts. In most of the experiments, ethylene glycol was not detected at all. An increase in temperature and pressure affected negatively the ethylene oxide selectivity, while an increase in the hydrogen peroxide concentration improved both the ethylene oxide selectivity and ethylene conversion. Ethylene epoxidation was comparable with propylene epoxidation, displaying, however, important differences in activity and selectivity, which were attributed to the partial pressures studied in the present work. It was demonstrated that TS-1 is a very selective and active catalyst for the selective epoxidation of ethylene with hydrogen peroxide.

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The adsorption efficiency of commercial activated carbon toward ibuprofen (IBU) was investigated and described using the adsorption dynamic intraparticle model (ADIM). Although the adsorption capacity of activated carbon has been widely studied, the kinetic models used in the literature are simplified, treating adsorption kinetics with pseudo-kinetic approaches. In this paper, a realistic model is proposed, quantitatively describing the influence of the main operation parameters on the adsorption kinetics and thermodynamics. The thermodynamic data were interpreted successfully with the Freundlich isotherm, deriving an endothermic adsorption mechanism. The system was found to be dominated by the intraparticle diffusion regime, and the collected data allowed the determination of the surface activation energy (E S = 60 ± 7 kJ/mol) and the fluid–solid apparent activation energy (E A = 6 ± 1 kJ/mol). The obtained parameters will be used to design adsorption columns, allowing the scale-up of the process.

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