Development of Catalytic Zeolite Membrane and Its Application to Simultaneous Resction and Separation

沸石是晶态硅酸铝，广泛用作催化剂和吸附剂。MFI型沸石的晶体内有细小的孔隙，其直径与苯的分子尺寸几乎相同。因此，该沸石具有较高的分子筛分效果。当成功将沸石制备成膜的形状时，该膜可以实现新的分离和高性能的同时反应和分离。本项目的主要目标是开发MFI型分子筛催化膜，并将其应用于高分离和同时反应分离过程。1997财政年度，我们开展了以下研究工作：采用一种新的方法--均匀混合水热合成法成功地制备了无针孔的MFI型分子筛催化膜。该膜具有良好的抗热冲击和机械冲击性能，可在773K以上温度下使用。二甲苯与邻位异构体…的分离系数1998财年，将该膜应用于高分离和同时反应分离过程，取得了以下结果：1)浓醋酸中水的选择性渗透：在温度为343K~363K，醋酸浓度为20%~98%的条件下，只有水可以透过膜；2)选择性分离氢气和氮气混合物中的氢，氧气和二氧化碳：在483K的流动体系中，氢与其他气体的分离系数约为100。3)同时反应和再生：甲醇的反应是一个连续的反应，如甲醇()SY三取代左。[)醚()SY三取代左。[)烯烃()SY三取代左。[)烷烃+芳烃。甲醇通过催化沸石膜扩散，进行反应。当甲醇转化为烯烃时，它们完全通过膜，获得高选择性的烯烃。烯烃选择性由常规固定床反应器的7%提高到85%以上。较少

Zeolites are crystalline alumino-silicate, and widely used as catalysts and adsorbents. MFI-type zeolite has fine pores within its crystals, the diameter of which is almost the same as the molecular size of benzene. Hence, the zeolite shows high molecular-sieving effect. When the zeolite is succeeded to be prepare in the shape of membrane, the membrane can enable to realize new separation and simultaneous reaction and separation with high performance. The main objective of this project is to development of MFI-type zeolite catalytic membrane, and to apply it to high separation and simultaneous reaction and separation processes.In fiscal year of 1997, we conducted the following research work :MFI-type catalytic membrane was succeeded to prepared without any pin-holes by a new method, well-mixed hydrothermal synthesis. This membrane was found to show high proof against thermal and mechanical shocks and to be used at above 773 K.The separation factor of para- to ortho-isomers of xylene an … More d diethyl-benzene was 3 and 7, respectively.In fiscal year of 1998, the membrane was applied to high separation and simultaneous reaction and separation processes, and the following results were obtained :1) Selective permeation of water from concentrated acetic acid : only water can permeate through the membrane under the conditions of temperature from 343 K to 363 K and the concentration of acetic acid from 20 to 98%.2) Selective separation of hydrogen from mixtures of hydrogen with nitrogen, oxygen and carbon dioxide : the separation factor of hydrogen to the other gas was found to be about 100 in the flow system at 483 K.3) Simultaneous reaction and regeneration : Reaction of methanol is a consecutive reaction, such as methanol (]SY.tri-substituted left.[) ether (]SY.tri-substituted left.[) olefin (]SY.tri-substituted left.[) paraffin+aromatics. Methanol diffuses through the catalytic zeolite membrane undertaking the reaction. When methanol is converted to olefin, they pass completely through the membrane, attaining high selectivity of olefin. The selectivity of olefin was enhanced up to 85% as compared with only 7% for the usage of conventional fixed bed reactors. Less