Preparation of Zeolite Film on the Surface of Ceramic Filter and Its Application to Reaction/Separation System

沸石是硅酸铝的晶体，具有微孔，其大小几乎与烃分子的大小相同。这种孔径大小反映了沸石的高择形性能。然而，这些沸石通常被制备成0.1-3毫米大小的粉状晶体。因此，本工作的主要目的是开发制备沸石薄膜的方法，并将所获得的薄膜应用于反应和分离在同一位置发生的体系。通过实验，我们得到了以下结果：1.用我们开发的方法在氧化铝陶瓷过滤器的表面制备了两种沸石薄膜：A型沸石和ZSM-5沸石。采用化学气相沉积技术，完全消除了硅酸铝非晶相对应的微孔。然而，对于A型沸石薄膜，很难消除与沸石晶体之间的孔相对应的大孔。生长的ZSM-5分子筛膜均有大孔存在。在甲苯-乙醇体系中，用所制备的ZSM-5分子筛膜进行渗透汽化，乙醇的分离系数可达100左右。

Zeolites are crystals of alumino-silicate, and have micro pores, the size of which are almost equal to those of hydrocarbon molecules. This pore size reflects on the high shape selectivity of zeolites. However, these zeolites are usually prepared as powdery crystals of 0.1-3 mm in size. Hence, the main objective of this work is to develop the method for preparing zeolites as thin films, and apply the obtained film to the system where the reaction and separation occur at the same position. From experiments we got the following results :1. The thin films of two kinds of zeolites ; A-type zeolite and ZSM-5 zeolite, were prepared on the surface of alumina ceramic filter by the methods developed by us.2. Micro pores, which correspond to amorphous phase of alumino-silicate, were completely eliminated by the technique of chemical vapor deposition. In case of A-type zeolite film, it was, however, difficult to eliminate macro pores, which correspond to the apertures among zeolite crystals. There were to any macro pores of as-grown ZSM-5 zeolite film.3. In the system of toluene-ethanol, the separation factor of ethanol of about 100 was achieved by the pervaporation technique using prepared the ZSM-5 zeolite film.