Preparation of silicalite-1 membrane by solution-filling method and its alcohol extraction properties

A new method called “solution-filling (SF)” was developed for preparing zeolite membranes. High performance silicalite-1 membranes were successfully synthesized on silica tubes by this method. It was found that the average total flux of membranes synthesized by using SF method can be improved by about 90% compared with that of membranes without using SF method. The effects of different porous supports, such as silica tubes and α-alumina tubes, on the separation performance of the as-synthesized silicalite-1 membranes was investigated. It was found that the separation performance of membranes synthesized on silica tubes were better than that of membranes synthesized on α-alumina tubes which suggested that silica tubes may be more suitable to synthesize high performance silicalite-1 membranes. Pervaporation experiments showed that the total fluxes of silicalite-1 membrane at 333 K were 2.63, 0.87, 0.24, and 0.20 kg/(m2 h) towards methanol/H2O, ethanol/H2O, 2-propanol/H2O, and 1-propanol/H2O mixtures, respectively, and the corresponding separation factors were 22, 69, 81, and 159, respectively.