摘要
采用智能质量分析仪IGA,在较高温度(150—300℃)下,测定5A分子筛对正己烷的吸附/脱附等温线,考察吸附温度对吸附等温线的影响,研究改性5A分子筛的二次孔结构与正己烷吸附/脱附及扩散性能的关系。结果表明:5A分子筛对正己烷的吸附等温线随着吸附温度的升高优惠程度逐渐降低,在300℃下,5A分子筛对正己烷吸附等温线接近线性,压力从14 kPa降至1.4 kPa,被5A分子筛吸附的正己烷可脱附出45.95%;在200℃下,改性5A分子筛(5A-11)对正己烷的脱附质量比是未改性(5A-1)的3.5倍;正己烷在5A-11分子筛上的脱附扩散系数为8×10-13m2/s,约是未改性的20倍;5A-11分子筛拥有较小的二次孔孔径和较为合理的大孔分布,使其对正己烷有着良好的脱附性能。
The adsorption and desorption isotherms of n-hexane on 5A zeolite were measured at 150-300 ℃ by Intelligent Gravimetric Analysis（IGA）.The effect of adsorption temperature on adsorption isotherms was investigated.The relationship of adsorption/desorption,the diffusion performance of n-hexane and mecrospore structure of 5A zeolite were studied.The results show that the adsorption isotherms degree of n-hexane reduces gradually with increasing adsorption temperature.At 300 ℃,adsorption isotherm of n-hexane is close to linear on 5A zeolite,the pressure reduces from 14 kPa to 1.4 kPa,the desorption capacity of n-hexane is 45.95% of adsorption capacity on 5A zeolite.At 200 ℃,the desorption capacity of n-hexane on modified 5A zeolite（5A-11） is 3.5 times that of unmodified 5A zeolite（5A-1）.The diffusion coefficient of n-hexane on 5A-11 zeolite is 8×10^-13 m^2/s,and 20 times that of 5A-1 zeolite.5A-11 zeolite has favorable desorption performance for n-hexane because it provides with smaller mecrospore diameter and preferable macrospore distribution.
出处
《化学工程》
CAS
CSCD
北大核心
2010年第11期1-4,共4页
Chemical Engineering(China)
基金
国家自然科学基金资助项目(20876074)
关键词
正己烷
5A分子筛
吸附
脱附
扩散
n-hexane
5A zeolite
adsorption
desorption
diffusion
