Sr^(2+)交换调控ETS-4分子筛选择性吸附CH_(4)中N_(2)性能  

Improvement on Selective Adsorption of N_(2) Over CH_(4) by ETS-4 Molecular Sieve via Sr^(2+)Ion-Exchange

作　　者：陈永灏 彭祺龙 姜豪 孙辉[1] 沈本贤[1] 张健[2] 李文龙 刘英杰 郭龙 CHEN Yonghao;PENG Qilong;JIANG Hao;SUN Hui;SHEN Benxian;ZHANG Jian;LI Wenlong;LIU Yingjie;GUO Long(Petroleum Processing Research Center, School of Chemical Engineering, East China University of Science and Technology,Shanghai 200237, China;Northwest Oilfield Branch, SINOPEC, Urumqi 830011, China)

机构地区：[1]华东理工大学化工学院石油加工研究所,上海200237 [2]中国石化西北油田分公司,新疆乌鲁木齐830011

出　　处：《石油学报（石油加工）》2022年第1期1-10,共10页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金项目(21878097,91634112和22178109);上海市自然科学基金(21ZR1417700)资助。

摘　　要：以正硅酸四乙酯为硅源、三氯化钛为钛源,采用水热法合成了Na-ETS-4材料,并通过Sr^(2+)交换和热处理制备了不同Sr^(2+)交换度的改性Sr-ETS-4样品;采用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线荧光光谱(XRF)、热重-差热(TGA-DSC)和拉曼光谱等手段对样品进行了分析表征;实验测定结合分子模拟的方法研究了改性前后分子筛样品对N_(2)和CH_(4)的吸附性能。结果表明:合成的Na-ETS-4与Sr-ETS-4样品均呈现片状堆叠的晶体结构;随着Sr^(2+)交换度的增加,改性Sr-ETS-4样品的热稳定性提高,N_(2)吸附速率增加,Sr-ETS-4-0.10-270样品的吸附速率常数较Sr-ETS-4-0.02-270样品提高了32倍,且N_(2)平衡吸附量逐渐上升。模拟计算结果也表明,Sr^(2+)交换改性可以增加ETS-4分子筛对N_(2)的吸附容量与N_(2)/CH_(4)分离因子。离子交换和热处理对ETS-4分子筛的调控显著提升了N_(2)/CH_(4)的平衡及动力学选择性,有助于实现天然气中N_(2)的选择性吸附分离。The Na-ETS-4 material was synthesized by hydrothermal method using tetraethyl orthosilicate as silicon source and titanium trichloride as titanium source.The modified Sr-ETS-4 samples with different exchange degrees were prepared by Sr ion exchange and heat treatment,and analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray fluorescence spectroscopy(XRF),thermogravimetry analysis(TGA)and Raman spectroscopy.The adsorption properties of the molecular sieve samples on nitrogen and methane before and after modification were investigated by experimental measurements combined with molecular simulations.Results show that a crystal structure of lamellar stacking is obtained in both synthesized Na-ETS-4 and Sr-ETS-4 samples.The thermal stability,nitrogen adsorption rate and adsorption capacity of the Sr-ETS-4 have been improved with the increase of Sr ion exchange degree.In addition,the adsorption rate constant of Sr-ETS-4-0.10-270 sample is 32 times higher than that of Sr-ETS-4-0.02-270 sample.Simulation calculation results also show that the Sr ion exchange modification increases the adsorption capacity of ETS-4 molecular sieve for nitrogen and the separation factor of nitrogen/methane.The tuning of ETS-4 molecular sieve by ion exchange and heat treatment significantly improve the equilibrium and kinetic selectivity of nitrogen over methane,which favors to realize the selective adsorption separation of nitrogen in natural gas.

关 键 词：ETS-4 天然气脱氮 选择性吸附 离子交换 

分 类 号：TQ028.3[化学工程]