The published kinetic models for methanol etherification over ZSM-5 zeolite were evaluated against our own experimental data. The process was investigated over a synthesized H-ZSM-5 zeolite using a laboratory fixed-bed reactor. The experiments were carried out at atmospheric pressure, temperatures of 170−270 °C, methanol feed concentrations up to 15 mol %, and gas phase velocity (WHSV) values in the range of 15−48 h −1 . The results showed a decrease of methanol conversion with respect to feed methanol concentration, with the single reaction product obtained in significant concentrations being dimethyl ether (no secondary products were observed in significant concentrations). The methanol conversion measurements were compared with theoretical predictions based on the main kinetic models published for methanol etherification over ZSM-5 zeolites with different acidities. As none of the published models fitted satisfactorily with our experimental data, we re-estimated the parameters of the tested models and applied a discrimination procedure in order to identify the most suitable one. The best quality of the fit was obtained by using an LH kinetic model based on the associative surface reaction mechanism. The adequacy of this kinetic model was confirmed by statistical and thermodynamic consistency criteria.

Three different inorganic scaffolds were obtained starting from the oxide system SiO2‒P2O5‒CaO‒MgO, to which Ce4+/Sm3+/Sr2+ cations were added in order to propose novel materials with potential application in the field of hard tissue engineering. Knowing the beneficial effects of each element, improved features in terms of mechanical properties, antibacterial activity and cellular response are expected. The compositions were processed in the form of scaffolds by a common sol-gel method, followed by a thermal treatment at 1000 and 1200 °C. The obtained samples were characterized from thermal, compositional, morphological and mechanical point of view. It was shown that each supplementary component triggers the modification of the crystalline phase composition, as well as microstructural details. Moreover, the shrinkage behavior is well correlated with the attained compression strength values. Sm was proven to be the best choice, since in addition to a superior mechanical resistance, a clear beneficial influence on the viability of 3T3 fibroblast cell line was observed.