低碳化学与化工2025，Vol.50Issue(7)：83-90,8.DOI:10.12434/j.issn.2097-2547.20240384
Cu基MOFs在低浓度煤层气CH4/N2吸附分离中的分子模拟研究
Molecular simulation study of Cu-based MOFs for CH4/N2 adsorption separation in low-concentration coalbed methane
摘要
Abstract
At present,China has the problem of insufficient capacity of conventional natural gas,and it needs to develop unconventional natural gas such as coalbed methane as a supplement.In the process of coal mining,a large amount of air will be mixed to form low-concentration coalbed methane(methane volume fraction is less than 30%),which leads to a series of problems such as resource waste.Therefore,improving the recovery and utilization rate of low-concentration coalbed methane has become an urgent problem to be solved.The adsorption and separation of CH4/N2 in low concentration coalbed methane was studied by using the combination of Grand canonical Monte Carlo and density functional theory.Cu-based metal organic framework(MOFs)(Cu-BTC,MOF-143,ATC-Cu and MOF-399)and ATC-M modified by different metals(Zn,Co and Mo)were selected as adsorption materials.The effects of different pore sizes and metal centers on the adsorption and separation performances of CH4/N2 by MOFs were studied.The results show that the pore size of MOFs has a significant impact on their adsorption capacity and CH4/N2 adsorption selectivity.The closer the pore size of MOFs is to the molecular kinetic diameter of the gas,the higher the CH4/N2 adsorption selectivity.Among the seven MOFs,ATC-Zn has a pore size(0.4995 nm)that is closer to the molecular kinetic diameters of CH4 and N2(CH4:0.380 nm,N2:0.364 nm),achieving the best CH4/N2 separation performance.Metal center modification has no significant effect on the pore size of ATC-M.The charge of the modified metal center is the main factor affecting the CH4/N2 adsorption and separation performance.The larger the bader charge of the metal ion,the better the CH4/N2 adsorption and separation performance of MOFs.Among the seven MOFs,ATC-Zn has the best CH4/N2 adsorption and separation performance.At 298 K and 100 kPa,when n(CH4):n(N2)of low-concentration coalbed methane is 1:9,the CH4/N2 adsorption selectivity of ATC-Zn reaches as high as 6.46,providing a new research idea for the recovery and utilization of CH4 in low-concentration coalbed methane.关键词
铜基MOFs材料/CH4/N2/吸附分离/低浓度煤层气/孔径/电荷Key words
Cu-based MOFs/CH4/N2/adsorption separation/low-concentration coalbed methane/pore size/charge分类
化学化工引用本文复制引用
仙梦丹,高学婷,李刚森,刘雷,黄伟,左志军..Cu基MOFs在低浓度煤层气CH4/N2吸附分离中的分子模拟研究[J].低碳化学与化工,2025,50(7):83-90,8.基金项目
国家自然科学基金(22078214) （22078214）
山西省重点研发计划(202102090301005) （202102090301005）
山西省科技创新人才团队专项资金(202204051001009). （202204051001009）
