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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/26528


    Title: The conversions of 1,3,5-trimethylbenzene over beta zeolite: Effect of SiO2/Al2O3 ratio
    Authors: Chu,SJ;Chen,YW
    Contributors: 化學工程與材料工程學系
    Keywords: DISPROPORTIONATION;ISOMERIZATION;TRANSALKYLATION;CATALYSTS;XYLENE
    Date: 1998
    Issue Date: 2010-06-29 17:30:09 (UTC+8)
    Publisher: 中央大學
    Abstract: A series of beta zeolites with various SiO2/Al2O3 ratios has been synthesized. These samples were characterized with respect to crystallinity, particle size, acidity and sorption capacities of water, n-hexane and cyclohexane. The conversion of 1,3,5-trimethylbenzene (TrMB) was conducted in a fixed bed reactor at 493-743 K and atmospheric pressure. The conversion of 1,3,5-TrMB decreased with an increase in the SiO2/Al2O3 ratio of the zeolite. The zeolites with low SiO2/Al2O3 ratio favored the disproportionation and the zeolites with high SiO2/Al2O3 ratio favored the isomerization. These can be interpreted by the acid concentration of zeolite. In the isomerization, all zeolites produced more 1,2,4-TrMB than 1,2,3-TrMB. In the disproportionation, the selectivity of tetra-methylbenzene (TeMB) was in the order of 1,2,3,5- > 1,2,4,5- > 1,2,3,4-TeMB. The concentration of 1,2,4,5-TeMB is greater than that at equilibrium. The results show that shape selectivity comes into effect. The reaction temperature and the reaction time on stream also affect the selectivity significantly due to coke formation in the zeolites. (C) 1998 SCI.
    Relation: JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
    Appears in Collections:[化學工程與材料工程研究所] 期刊論文

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