关键词: 正庚烷, 正辛烷, 5A分子筛, 吸附动力学

Abstract: Adsorption kinetics of n-heptane and n-octane on 5A molecular sieve pellets with/without binder was studied using gravimetric method. Diffusivities were derived from the simplified model and diffusion activation energies were evaluated. Results show that the diffusion time constants of n-paraffins on binder-free pellets are larger than those of adsorbates on pellets with binder. In the temperatures range of 300-480 K, the micropore diffusivities of n-pentane and n-hexane on binder-free pellets are (20.84~85.77)×10-14 and (3.80-23.44)×10-14 cm2/s, respectively; the macropore diffusivities of n-pentane and n-hexane on pellets with binder are (4.87-38.58)×10-7 and (4.28-14.65)×10-7 cm2/s, respectively. The diffusion activation energies of n-pentane and n-hexane are 10.74 and 12.71 kJ/mol on binder-free 5A molecular sieve respectively, 14.16 and 16.35 kJ/mol on 5A molecular sieve with binder respectively.

Key words: n-heptane, n-octane, 5A zeolite, adsorption kinetics