RHO分子筛空分性能评价

Air Separation Performance Evaluation of RHO Molecular Sieve

RHO分子筛由于独特的孔道结构在O_(2)N_(2)分离方面表现出其特有的性质。采用水热合成法合成Na,Cs-RHO分子筛,进行碱金属离子交换改性,然后利用XRD和SEM对样品进行表征。通过单组分气体吸附实验、Aspen Adsorption软件模拟混合组分穿透曲线实验和双塔PSA空分实验对吸附剂性能进行评价。结果表明:Li-RHO是一种容易通过阳离子调控骨架扭曲程度的分子筛,O_(2)N_(2)平衡分离性能参数最大。穿透曲线实验结果表明,弱吸附组分(N2)首先穿透吸附床,O2因强吸附而后穿出,Li-RHO的动力学分离因子很高。Aspen Adsorption模拟结果表明,Li-RHO制得的N2纯度和回收率最高,可能是一种具有良好应用前景的空分吸附剂。

RHO molecular sieves demonstrate unique properties in O_(2)/N_(2)separation due to their special pore structure.The Na,Cs-RHO molecular sieves were synthesized by hydrothermal synthesis,modified by alkali metal ion exchange,and then the samples were characterized by XRD and SEM.Adsorbent performance was evaluated by single-component gas adsorption experiments,Aspen Adsorption software simulation of mixed component penetration curve experiments and two-tower PSA air separation experiments.The results of adsorption experiments showed that Li-RHO was a molecular sieve that could easily adjust the degree of framework distortion by cations and had the largest O_(2)/N_(2)equilibrium separation performance parameters.The results of the breakthrough curve showed that the weakly adsorbed component(N_(2))penetrated the adsorption bed first,and O_(2)penetrated out later due to strong adsorption,and the kinetic separation factor of Li-RHO was high.The results of Aspen Adsorption simulation showed that Li-RHO produced the highest purity and recovery of N_(2),and may be a promising adsorbent for air separation.