摘要
The performance of various types of zeolites for N2/O2 and CH4/N2 separation has been studied. The separation factors αN2/O2 and αCH4/N,2 for all the Na-form zeolites are < 1. Compared with Na-form zeolites, H-form zeolites adsorb larger quantities of O2 and smaller quantities of N2, so αN2/O2 is increased, but αCH4/N2 is reduced. On the contrast, Ca-form zeolites adsorb larger quantities of N2, so αN2/O2 is reduced but αCH4/N2 is increased. However the αN2/O2 and αCH4/N2 for both H- and Ca- form zeolites are <1. The changes in adsorption behavior can be explained in the light of energetics of sorption in zeolites. Chemical vapor deposition with silicon methoxide has been used to control the pore-opening size of the zeolites. As the amount of SiO2 deposition on NaA is increased, the adsorption of the bulkier component in the binary gas mixture is suppressed, so the values of αN2/O2 and αCH4/N2 for SiNaA zeolites are increased qulckly to>1. Experimental results show that if the right type of zeolite is chosen fine control of zeollte pore-opening size through chemical vapor deposition has a potential as a good method for preparing high selective adsorbent in gas separation.
The performance of various types of zeolites for N2/O2 and CH4/N2 separation has been studied. The separation factors αN2/O2 and αCH4/N,2 for all the Na-form zeolites are < 1. Compared with Na-form zeolites, H-form zeolites adsorb larger quantities of O2 and smaller quantities of N2, so αN2/O2 is increased, but αCH4/N2 is reduced. On the contrast, Ca-form zeolites adsorb larger quantities of N2, so αN2/O2 is reduced but αCH4/N2 is increased. However the αN2/O2 and αCH4/N2 for both H- and Ca- form zeolites are <1. The changes in adsorption behavior can be explained in the light of energetics of sorption in zeolites. Chemical vapor deposition with silicon methoxide has been used to control the pore-opening size of the zeolites. As the amount of SiO2 deposition on NaA is increased, the adsorption of the bulkier component in the binary gas mixture is suppressed, so the values of αN2/O2 and αCH4/N2 for SiNaA zeolites are increased qulckly to>1. Experimental results show that if the right type of zeolite is chosen fine control of zeollte pore-opening size through chemical vapor deposition has a potential as a good method for preparing high selective adsorbent in gas separation.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1995年第10期912-915,共4页
Acta Physico-Chimica Sinica
基金
国家重大基础研究项目
关键词
分子筛
甲烷
氮气
氧气
分离
孔口改性
N_2/O_2 separation, CH_4/N_2 separation, Zeolites, Chemical vapor deposition, Controlled pore-opening size
