外文翻譯--氣相轉(zhuǎn)移法合成mfi型沸石分子篩分離丁烷和二甲苯異構(gòu)體（英文）

1、Journal of Membrane Science 178 (2000) 25–34Separation of butane and xylene isomers with MFI-type zeolitic membrane synthesized by a vapor-phase transport methodTakaaki Matsufuji a, Norikazu Nishiyama a, Masahiko Matsuka

2、ta b,1, Korekazu Ueyama a,?a Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka-shi, Osaka 560-8531, Japan b Department of Applied Chemistry, Wased

3、a University, 3-4-1 Okubo, Shinnjyuku-ku, Tokyo 169-8555, JapanReceived 25 October 1999; received in revised form 2 March 2000; accepted 1 May 2000AbstractMFI-type zeolitic membranes were prepared by a vapor-phase transp

4、ort (VPT) method on porous ?-alumina flat disks. Single- and mixed-gas permeation measurements of butane isomers were performed in the temperature range of 300–375 K. The separation factor was always greater than the ide

5、al selectivity. This result is explained by the preferential adsorption of n-butane on MFI in the binary system. The pervaporation tests for xylene isomers were performed at 303 K. p-Xylene was the most permeable compone

6、nt in the unary system. In the permeation measurements of a binary mixture of p-xylene/m-xylene and a ternary mixture of p-xylene/m-xylene/o-xylene, p-xylene predominantly permeated in the early stage, and then, the flux

7、 of p-xylene decreased gradually and finally became lower than that of the other xylene isomers. The adsorption of m-xylene in the pores of MFI seemed to block the permeation of p-xylene. © 2000 Elsevier Science B.V

8、. All rights reserved.Keywords: Zeolite membrane; MFI; Gas separation; Adsorption; Pervaporation1. IntroductionIn recent years, zeolitic membranes have been synthesized by a hydrothermal method [1–21] and a vapor-phase t

9、ransport (VPT) method [22–28]. Since the size of zeolite pores is similar to the molecular dimension, both selective adsorption and molecular sieving play an important role in the separation of hydrocarbon mixtures. Inte

10、resting features on the? Corresponding author. Tel.: +81-6-6850-6255; fax: +81-6-6850-6255. E-mail addresses: mmatsu@mn.waseda.ac.jp (M. Matsukata), ueyama@cheng.es.osaka-u.ac.jp (K. Ueyama). 1 Tel.: +81-3-5286-3850; fax

11、: +81-3-5286-3850.separation of hydrocarbons using zeolitic membranes have been reported [1–28]. Separation using MFI-type zeolitic membranes were reported most often with respect to the separa- tion of linear and branch

12、ed hydrocarbon mixtures such as n-butane/i-butane [4,5,7,8,10–12] and n-hexane/2,2- dimethylbutane [4,10,12]. MFI has a framework struc- ture composed of two types of intersecting channels which are both defined by 10-me

13、mbered rings (MRs). Reported separation factors for the n-butane/i-butane and n-hexane/2,2-dimethylbutane mixtures were in the range of 20–60 and over 600, respectively, at room temperature. In addition to the separation

14、 of linear and branched hydrocarbon mixtures, the separation of aromatic0376-7388/00/$ – see front matter © 2000 Elsevier Science B.V. All rights reserved. PII: S0376-7388(00)00462-2T. Matsufuji et al. / Journal of

15、Membrane Science 178 (2000) 25–34 27Fig. 1. Schematic diagram of the experimental apparatus for per- vaporation.2.3. Permeation measurementsEpoxy resin was used as a sealant between mem- brane and apparatus. As pretreatm

16、ent for permeation tests, water adsorbed in the zeolitic membrane was removed by evacuation at 420 K for 2 h. Before each permeation experiment, the membrane was calcined for 4–10 h at 773 K to remove adsorbed components

17、 and epoxy resin.2.3.1. Pervaporation In order to evaluate the compactness of the MFI membranes, the pervaporation of 1,3,5-triisopropyl- benzene (TIPB) with a kinetic diameter (0.85 nm) larger than the pore dimensions o

18、f MFI (0.53 nm×0.56 nm, 0.51 nm×0.55 nm) was carried out for 25 h at 303 K. The zeolitic membrane was attached at one end of a glass tube with a cross-sectional area of 0.50×10?4 m2. Liquid TIPB were poure

19、d in the glass tube, as shown in Fig. 1. The permeation side wasFig. 2. Schematic diagram of gas permeation measurements.kept under vacuum. The permeant was continuously collected for 25 h in a cold trap using liquid nit

20、rogen and analyzed by a gas chromatograph equipped with a flame ionization detector. Pervaporation of xylene isomers were also perfor- med at 303 K. Single, binary (p-xylene/m-xylene) and ternary (p-xylene/m-xylene/o-xyl

21、ene) components of xylene isomers were tested. The compositions of the feed mixture were determined by the gas chromato- graph.2.3.2. Gas permeation measurements Gas permeation measurements were performed us- ing a press

22、ure gradient (PG) method. The permeation measurements were operated in a batch-wise manner, as shown in Fig. 2. In the PG method, the total pressure of the feed side was monitored using the pressure transmitter during th

23、e permeation measurement. The permeation side was evacuated to less than 50 Pa. This condition is referred to as vacuum. Single-gas permeation tests for He, N2, n-butane, i-butane and SF6 were performed in the temperatur

24、e range of 300–375 K. The perme- ances of these gases at atmospheric pressure were determined by using the rate of pressure decrease of the feed side from 105 to 95 kPa. Ideal selectivity was calculated from the ratio of

25、 permeances. Mixed-gas permeation measurements of butane isomers mixture were performed in the temperature range of 300–375 K. The initial feed gas and final feed gas were analyzed with a gas chromatograph (Ohkura, Model