The determination of zeolite crystal diffusivity by gas chromatography—II. Experimental

✍ Scribed by A.S. Chiang; A.G. Dixon; Y.H. Ma

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 715 KB
• Volume: 39
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(84)80004-4

✦ Synopsis

Experimental results are reported for the adsorption of propane and n-butane in a column packed with Linde 5A ZeoIite crystals, and methane, propane, a-and ire-butane in a column packed with silicalite crystals. The adsorption equilibrium constant K and crystal diffusivity 0, were obtained at different temperatures in the range lOO-3OO"C, for each sorbate and packing and the heat of adsorption and diffusional activation energy were determined. The results show that in order to separate the effects of K and the pressure drop, the latter must be independently estimated by a suitable correlation. The values of X thus obtained agree well with current iiterature and are well-determined. Similarly. there is a hiah correlation between D, and the axial diffusivity D,, which may be resolved by fitting the model simultane&sly to runs made at boih high and low velocitiei. The values of DC found are in broad agreement with the results of adsorption rate measurements for the Linde 5A zeolite. For the silicalite lower diffusivities were obtained, which may point to a surface resistance or a wncentrationdependent diffusivity.