Diffusion of oxygen and nitrogen in 5A zeolite crystals and commercial 5A pellets

✍ Scribed by Douglas M. Ruthven; Zhige Xu

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 526 KB
• Volume: 48
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(93)80214-b

✦ Synopsis

The diffusion of oxygen and nitrogen in large laboratory synthesized crystals of SA zeolite and in commercial 5A adsorbent pellets was studied by the zero length column (ZLC) method. The data clearly show that intracrystalline diffusion is much too fast to exert any significant influence on the sorption kinetics in the commercial adsorbent and the dominance of macropore diffusional resistance was confirmed by replicate experiments with different particle size fractions. At subambient temperatures surface diffusion makes a significant contribution to the macro diffusivity, especially for nitrogen, leading to interesting trends for the concentration and temperature dependence. These effects are analyzed in detail.