Thesis (M.Eng.)--Chulalongkorn University, 2001

A pervaporative membrane reactor for the synthesis of ethyl tert-butyl ether (ETBE) from a liquid phase reaction between ethanol (EtOH) and tert-butyl alcohol (TBA) was investigated. The study was divided into 3 main parts: kinetic study of supported beta-zeolite, study on permeation through polyvinyl alcohol (PVA) membrane and study on pervaporative membrane reactor. The supported beta-zeolite was selected because of better performance compared to a commercial catalyst, Amberlyst-15. The kinetic study was carried out using a semi-batch reactor. The effect of external mass transfer was investigated by varying stirring speeds. Three temperature levels of 323, 333 and 343 K were performed in the study to obtain the parameters in the Arrheniusʼ equation and the Vanʼt Hoff equation. Both concentration-based and activity-based models can fit the experimental results well. The permeation studies of H[subscript 2]O-EtOH binary system revealed that the membrane worked effectively for H[subscript 2]O removal at the mixtures containing H[subscript 2]O content lower than 62mol%. The permeation studies of quaternary mixtures (H2O-EtOH-TBA-ETBE) were performed at 3 temperature levels of 323, 333 and 343 K. It was found that the membrane was preferentially permeable to H[subscript 2]O. The permeability coefficients were correlated with the Arrheniusʼ equation. In the pervaporative membrane reactor studies, both experiment and simulation were carried out. An activity-based model was developed to investigate the performance of the pervaporative membrane reactor using parameters obtained from the independent experiments. Simulation results agreed well with experimental results. It was observed that the ratio of initial mole of EtOH to TBA, the ratio of membrane area to initial mole of TBA, the ratio of the amount of catalyst to initial mole of TBA and the operating temperature played important roles on the reactor performance. The analysis of the operating temperature and the ratio of membrane area to initial mole of TBA showed an optimum yield due to the competing effect of rate of reaction and rate of reactant losses.