文献类型：期刊文献

英文题名：Thermodynamic analysis of molecular simulations of N-2 and O-2 adsorption on zeolites under plateau special conditions

作者：Fu, Yaoguo[1,2];Liu, Yingshu[1,2];Yang, Xiong[1,2];Li, Ziyi[1,2];Jianh, Lijun[1];Zhang, Chuanzhao[3];Wang, Haoyu[3];Yang, Ralph T.[4]

第一作者：Fu, Yaoguo

通讯作者：Li, ZY[1]

机构：[1]Univ Sci & Technol Beijing, Sch Energy & Environm Engn, Beijing 100083, Peoples R China;[2]Beijing Higher Inst Engn Res, Ctr Energy Conservat & Environm Protect, Beijing 100083, Peoples R China;[3]Beijing Union Univ, Coll Biochem Engn, Beijing 100023, Peoples R China;[4]Univ Michigan, Dept Chem Engn, Ann Arbor, MI 48109 USA

第一机构：Univ Sci & Technol Beijing, Sch Energy & Environm Engn, Beijing 100083, Peoples R China

通讯机构：[1]corresponding author), Univ Sci & Technol Beijing, Sch Energy & Environm Engn, Beijing 100083, Peoples R China.

年份：2019

卷号：480

起止页码：868-875

外文期刊名：APPLIED SURFACE SCIENCE

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000463008200098)】；

基金：The authors would like to express the gratitude to the National Key R&D Program of China (No. 2017YFC0806304), the National Postdoctoral Program for Innovative Talents (No. BX201700029), the China Postdoctoral Science Foundation (No. 2018M630075), the Fundamental Research Funds for the Central Universities (No. FRF-TP-17-063A1, FRF-BD-18-015A), and the Beijing Natural Science Foundation (No. 8174064, 8182019). Thanks to the National Supercomputing Shenzhen Center (Shenzhen Cloud Computing Center) for the help on molecular simulation calculations.

语种：英文

外文关键词：Adsorption thermodynamics; PSA oxygen production; Molecular simulation; Adsorption heterogeneity; Zeolites

摘要：Adsorption thermodynamics of N-2 and O-2 on two most commonly used zeolites (5A and Li-LSX) under plateau special conditions of wide ranges of temperature (238-298 K) and pressure (0-300 kPa) for pressure swing adsorption (PSA) oxygen production were studied based on molecular simulations and theoretical model fitting. Adsorption isotherms for each adsorbate-adsorbent pair at different temperatures were fitted by Langmuir, Freundlich and Sips models, obtaining equilibrium parameters including adsorption capacity, strength, heterogeneity and N-2/O-2 selectivity. Thermodynamic parameters such as Gibb's free energy, enthalpy, and entropy changes were numerically derived, and isosteric adsorption heats and distributions of potential energy were simulated. The results suggest that the adsorption capacity and affinity follow the order of N-2-Li-LSX > N-2-5A > O-2-5A > O-2-Li-LSX, leading to higher N-2/O-2 selectivity on Li-LSX compared to 5A. For Li-LSX, N-2/O-2 selectivity increases significantly with temperature above 273 K due to the difference in adsorption thermodynamics of N-2 and O-2 varying with temperature in terms of different adsorption heterogeneities. For 5A, the homogeneous distributions of N-2 and O-2 as well as the wide scopes of affinities from Na+ and Ca2+ exhibit N-2/O-2 selectivity with negligible temperature dependence, which is beneficial for stable oxygen production with a fixed PSA process under large day-and-night temperature difference. This study provides theoretical basis for obtaining an optimal balance between efficiency and stability of oxygen production by using a proper mixture of Li-LSX and 5A.