Sorption and diffusion of benzene in HZSM-5 and silicalite crystals
Sorption and diffusion of benzene in HZSM-5 and silicalite crystals
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DOI：
10.1002/aic.690341016
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发表时间：
1988-10
期刊：
影响因子：
3.7
通讯作者：
D. B. Shah;D. Hayhurst;G. Evanina;Chang-Jie Guo
中科院分区：
文献类型：
--
作者：
D. B. Shah;D. Hayhurst;G. Evanina;Chang-Jie Guo
基于十元氧环的中孔沸石如ZSM-5和ZSM-11的发现促使沸石在许多新型分离、吸附和择形催化过程中的应用显著增加。ZSM-5具有与许多商业上重要的芳族化合物和取代的链烷烃分子相同的孔径。基于扩散分子的尺寸和构型，ZSM-5被提出了广泛的吸附和催化应用。Jacobs等人测定了芳烃在ZSM-5及其贫铝结构类似物硅沸石上的吸附平衡，并对芳烃在ZSM-5上的吸附行为进行了研究。（I 98 I），Stach et al.（1986）和Pope（1984，1986）。Doelle等人研究了苯在ZSM-5上的吸附。（1981）以及Choudhary和Srinivasan（1987 a）的研究。Wu等报道了气相中C6-C1芳烃在硅质岩中的吸附和扩散。（1983）以及Choudhary和Singh（1986）对液相ZSM-5的研究。Choudhary和Srinivasan（1987 b，c）使用动态吸附/解吸技术测量了催化条件下苯在HZSM-5中的扩散。当从上述来源的吸附和扩散数据进行分析，吸附容量的数据是一致的。例如，发现ZSM-5对苯的极限吸附容量为0.1至0.12 kg/kg。然而，对于扩散，报告的数据没有显示出相同的一致性。例如，已经发现环状烃如苯的校正扩散率Do的值在两到三个数量级上变化[S X m2/s，如Wu等人报道的。（1983）在373 K时的结果与Zikanova等人报告的5倍结果相比。（1987）在393 K处]。奥尔森内尔Choudhary和Srinivasan（1987 b）报告的瓦尔-
The discovery of intermediate-pore zeolites such as ZSM-5 and ZSM-11 based on the ten-membered oxygen rings prompted considerable increase in the use of zeolites in many novel separative, adsorptive and shape-selective catalytic processes. ZSM-5 has the same pore size as many of the commercially important aromatics and substituted paraffinic molecules. A wide range of adsorptive and catalytic applications of ZSM-5 has been proposed based on the size and configuration of diffusing molecules. Few studies, however, have been reported on intrinsic sorption and diffusion of aromatics and substituted parafins in this zeolite.The adsorption equilibria of aromatic hydrocarbons on ZSM-5 and its aluminum-deficient structural analog silicalite have been measured by Jacobs et al.(I 98 I), Stach et al.(1 986), and Pope (1984, 1986). Adsorption of benzene on ZSM-5 has been investigated by Doelle et al.(1981) and by Choudhary and Srinivasan (1 987a). Adsorption and diffusion of C6-C, aromatics in silicalite from the gas phase have been reported by Wu et al.(1983) and for ZSM-5 in liquid phase by Choudhary and Singh (1986). Choudhary and Srinivasan (1987b, c) have measured diffusion of benzene in HZSM-5 under catalytic conditions using a dynamic sorption/desorption technique. When the sorption and diffusion data from above sources are analyzed, the data on sorption capacity are found to be consistent. For example, the limiting sorption capacity of ZSM-5 for benzene is found to be 0.1 to 0.12 kg/kg. For diffusion, however, the reported data do not show the same consistency. For example, the values of corrected diffusivities, Do, for a cyclic hydrocarbon such as benzene have been found to vary over two to three orders of magnitude [S x m2/s as reported by Wu et al.(1983) at 373 K vs. 5 x reported by Zikanova et al.(1987) at 393 K]. Olsonetal.(1981) reportedavalueof 10-" at 588 K, whereas Choudhary and Srinivasan (1987b) report val-