高校化学工程学报2011，Vol.25Issue(1)：172-176,5.
正庚烷在5A分子筛上的高温吸附/脱附及扩散性能
Adsorption/Desorption and Diffusion Property of n-Heptane on 5A Molecular Sieves under High Temperature
摘要
Abstract
The adsorption and desorption isotherms and the hysteresis loop of n-heptane on 5A molecular sieves (self-made) were analyzed by Intelligent Gravimetric Analyzer (IGA-100 type) under the higher temperature. The adsorption heat and adsorption/desorption diffusion coefficients of n-heptane on 5A molecular sieves were calculated. The adsorption mechanism of n-heptane in the 5A molecular sieves microporous were analyzed. The results show that: By increasing the adsorption temperature, the preferential degree decreases obviously and the hysteresis loop is formed. At 523 K, the equilibrium adsorption amount of n-heptane is 0.0884 kg.kg-1, which decreases 23.42％ than that at 423 K, but the desorption amount is 2.6 times of that at 423 K. The isosteric adsorption heat of n-heptane is 38.23～62.70 kJ-mol-1, which is obviously higher than its condensation heat. When the temperature between 423 K and 523 K, the adsorption/desorption diffusion coefficients of n-heptane are 10-11～10-9cm2.s-1. When the adsorption amount is 0.0732 kg·kg-1 at 523 K, the adsorption diffusivity of n-heptane reaches to 6.646× 10-10 cm2-s-1, which is about 3.8 times of that at 423 K, and the desorption diffusion coefficient (11.22×10-10 cm2.s-1) is 1.9 and 23.0 times of that at 473 K and 423 K,respectively. At the temperature below 473 K, the desorption diffusion coefficients are lower than the adsorption diffusion coefficients; At higher temperature (523 K, 473 K), the effect of adsorption amount on adsorption/desorption diffusion coefficients is obviously larger than that at 423 K. The desorption temperature of n-heptane is unsuitable to be lower than 473 K.关键词
正庚烷/5A分子筛/吸附等温线/扩散系数/吸附热Key words
n-heptane/ 5Amolecular sieves/ adsorption isotherms/ diffusion coefficient/ adsorption heat分类
化学化工引用本文复制引用
康亚飞,杜旭东,刘宗健,崔群,王海燕,姚虎卿..正庚烷在5A分子筛上的高温吸附/脱附及扩散性能[J].高校化学工程学报,2011,25(1):172-176,5.基金项目
国家自然科学基金(20876074). （20876074）
