KCaA型分子筛制备及其对CO2吸附性能的研究

采用离子交换法,在CaA型分子筛中加入氯化钾水溶液,并搅拌一定时间,将功能K+引入到CaA型分子筛结构中,以调控CaA型分子筛的孔径和增加它的吸附活性位点.考察了离子交换时间和气体吸附压力等条件对制备的KCaA型分子筛的结构、形貌和CO2吸附性能的影响.通过X射线衍射、扫描电子显微镜和CO2吸附等温线等表征手段,结果发现:获得的KCaA型分子筛具有与CaA型分子筛相同的结构与形貌;增大气体吸附压力,分子筛对CO2的吸附量增大;但随着离子交换时间的增长,分子筛对CO2的吸附能力先增大后减小;在室温及1bar气压下对CO2气体的吸附性能比原CaA型分子筛提高了26.7%.

Synthesis of KCaA Molecular Sieve and its CO2 Adsorption Capacity

The KCaA molecular sieve is prepared using the ion exchange method in which potassium chloride solution is used with stirring process.K + is added to the CaA molecular sieve to regulate its pore size and enhance its CO2 adsorption sites.The ion exchange time and the sorption pressure are investigated in this work. X-ray diffraction,scanning electron microscopy,energy dispersive spectrometer and the pressure composition isotherms technique are used to characterize the molecular sieves.Results indicate that the structure and morphology of the KCaA molecular sieve are the same with that of CaA molecular sieve;CO2 adsorption capacity of KCaA molecular sieves first increases with the increase of the testing pressure,followed by slightly decreasing as the ion exchange time increases;Moreover,CO2 adsorption capacity of the KCaA molecular sieve is found to be apparently higher(26.7%)than that of original CaA molecular sieve under a pressure of 1 bar.