DIFFUSION MECHANISM OF HYDROCARBONS IN ZEOLITES .2. ANALYSIS OF EXPERIMENTAL-OBSERVATIONS

被引:141
作者
XIAO, JR [1 ]
WEI, J [1 ]
机构
[1] MIT,DEPT CHEM ENGN,CAMBRIDGE,MA 02139
关键词
D O I
10.1016/0009-2509(92)80237-7
中图分类号
TQ [化学工业];
学科分类号
0817 ;
摘要
The influence of the properties of molecule-zeolite systems on the diffusional and equilibrium behavior is experimentally investigated. Sixteen hydrocarbons, including paraffins, two aromatics and a naphthene, were studied in ZSM-5. The activation energy for diffusion is mainly responsible for the different diffusivities of various compounds. The diffusion coefficients of benzene, toluene, and 2-methylbutane in ZSM-5 are insensitive to the concentration up to about four molecules/unit cell, and the isotherms within this concentration range are of the Langmuir type. At higher concentrations, the diffusivities show strong concentration-dependent trends, and the Langmuir adsorption parameter sharply decreases. The predictions of the mechanistic models proposed in Part I agree, in general, with the experimental results of the diffusion measurements here, both with regard to the order of magnitude and the concentration dependence. Good agreement is also found for 5A between the theoretical predictions and literature data on the diffusion and equilibrium behavior.
引用
收藏
页码:1143 / 1159
页数:17
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共 57 条
  • [1] SORPTIVE AND MOLECULAR-SIEVE PROPERTIES OF A NEW ZEOLITIC MINERAL
    BARRER, RM
    RILEY, DW
    [J]. JOURNAL OF THE CHEMICAL SOCIETY, 1948, (FEB): : 133 - 143
  • [2] DIFFUSION OF SOME N-PARAFFINS IN ZEOLITE A
    BARRER, RM
    CLARKE, DJ
    [J]. JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS I, 1974, 70 (03): : 535 - 548
  • [3] MOLECULAR DIFFUSION IN CHABAZITE, MORDENITE AND LEVYNITE
    BARRER, RM
    BROOK, DW
    [J]. TRANSACTIONS OF THE FARADAY SOCIETY, 1953, 49 (09): : 1049 - 1059
  • [4] Kinetics of formation of zeolitic solid solutions.
    Barrer, RM
    Ibbitson, DA
    [J]. TRANSACTIONS OF THE FARADAY SOCIETY, 1944, 40 : 0206 - 0216
  • [5] Migration in crystal lattices.
    Barrer, RM
    [J]. TRANSACTIONS OF THE FARADAY SOCIETY, 1941, 37 : 0590 - 0599
  • [6] BARRER RM, 1971, P ROY SOC LOND A MAT, V332, P1
  • [7] Benson, 1976, THERMOCHEMICAL KINET, V23, P613
  • [8] BRECK DW, 1974, ZEOLITE MOL SIEVES, P636
  • [9] SORPTION KINETICS OF NORMAL-HEXANE ON MGA ZEOLITES OF DIFFERENT CRYSTAL SIZES - STUDY OF THE RATE-LIMITING TRANSPORT MECHANISM
    BULOW, M
    STRUVE, P
    FINGER, G
    REDSZUS, C
    EHRHARDT, K
    SCHIRMER, W
    KARGER, J
    [J]. JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS I, 1980, 76 : 597 - &
  • [10] INFLUENCE OF HYDROTHERMAL PRE-TREATMENT ON ZEOLITIC DIFFUSIVITY DETECTED BY COMPARATIVE SORPTION KINETICS AND SMALL-ANGLE X-RAY-SCATTERING INVESTIGATIONS
    BULOW, M
    STRUVE, P
    PIKUS, S
    [J]. ZEOLITES, 1982, 2 (04): : 267 - 270