Pervaporation and vapour permeation of methanol and MTBE through a microporous methylated silica membrane

Abstract

The combination of conventional unit operations with pervaporation or vapour permeation membrane separation processes offers opportunities for process intensification in terms of augmenting capacity and decreasing energy consumption of conventional unit operations. The MTBE production process is an often studied example of a so-called hybrid process in which distillation is combined with pervaporation or vapour permeation. In this work transport of pure methanol through and separation of methanol from MTBE by a supported microporous methylated membrane (developed by the Energy research Centre of the Netherlands) is studied. Several aspects of modelling of transport through the support layers and the selective layer are addressed, thereby comparing the Maxwell-Stefan equations for pure methanol transport with a practical engineering model. From experiments performed at temperatures up to 140°C it appeared that both the selectivity towards methanol and flux of the membrane are high. The thesis ends with a study comparing pervaporation and vapour permeation on laboratory scale as well as on large scale by simulations.