CO_(2)在{[Bmim][BF_(4)]+碱金属盐}金属络合离子液体中的溶解度及溶解机理研究  

10On the solubility and dissolution mechanism of CO_(2) in{[Bmim][BF_(4)]+alkali metal salt}metal complex ionic liquid

作　　者：王兰云[1,2,3] 周华健 张亚娟 WANG Lanyun;ZHOU Huajian;ZHANG Yajuan(School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,Henan,China;Cultivation Base of State Key Labora-tory of Gas Geology and Gas Control,Henan Polytechnic University,Jiaozuo 454000,Henan,China;Co-construction and Cooperation Between the Provinces and Departments for Safe Production and Clean and Efficient Utilization of Coal Innovation Center,Henan Polytechnic University,Jiao-zuo 454000,Henan,China)

机构地区：[1]河南理工大学安全科学与工程学院,河南焦作454000 [2]河南理工大学瓦斯地质与瓦斯控制国家重点实验室培育基地,河南焦作454000 [3]河南理工大学煤炭安全生产与清洁高效利用省部共建协同创新中心,河南焦作454000

出　　处：《河南理工大学学报（自然科学版）》2023年第6期86-95,共10页Journal of Henan Polytechnic University（Natural Science）

基　　金：国家自然科学基金资助项目(51874124,52074108);河南省科技攻关项目(212102310007);河南省高校重点科研项目(22A620001);河南省高校创新人才项目(22HASTIT012)。

摘　　要：为更加经济有效地捕获CO_(2),减少环境污染,加强资源合理利用,制备不同浓度的[Bmim][BF_(4)]+MBF_(4)(M=Li^(+),Na^(+)和K^(+))金属络合离子液体,在压力100~4 000 k Pa,温度30,40,50℃条件下,使用反应釜进行气体吸收试验,测定CO_(2)在金属络合离子液体(metal complex ionic liquids,MILs)中的溶解度,并采用密度泛函模拟计算MILs与CO_(2)混合体系的稳定构型的电荷分布、Fukui指数和结合能参数,从微观角度分析MILs吸收CO_(2)机理。结果表明:CO_(2)在MILs中的溶解度随温度升高和压力降低而降低;添加碱金属盐可促进离子液体(ionic liquids,ILs)对CO_(2)的吸收,但当ILs中碱金属盐浓度≥1 mol/L时会抑制CO_(2)吸收;0.010 mol/L的[Bmim][BF_(4)]+KBF_(4)吸收CO_(2)量最高;密度泛函计算结果显示[Bmim][BF_(4)]+KBF_(4)体系的K^(+)体积大,氢键作用力强,且K+在ILs中溶解度小,造成的空间位阻较小,因而拥有更多的自由体积容纳CO_(2)。与纯ILs相比,MILs具有更高的CO_(2)吸收量,在温室气体治理中具有较好的应用前景。In order to capture carbon dioxide more economically and effectively,reduce environmental pollu‐tion,and strengthen the rational use of resources,various concentrations of metal complex ionic liquids[Bmim][BF_(4)]+MBF_(4)(M=Li^(+),Na^(+)and K^(+))were prepared in this paper.Under the pressure range of 100~4000 kPa,the gas absorption experiment was carried out at 30,40 and 50℃by using a high-pressure reactor,and the solubility of CO_(2)in metal complex ionic liquids(MILs)was measured.Density functional simulation was used to calculate the charge distribution,Fukui index,and binding energy parameters of the stable con‐figuration of the mixed system of MILs and CO_(2),and to analyze the CO_(2)absorption mechanism of MILs from a microscopic perspective.The experimental results show that the solubility of CO_(2)in MILs decreases with increasing temperature and decreasing pressure.Adding alkali metal salt can promote the absorption of CO_(2)by ILs,but when the concentration of alkali metal salt in ILs is≥1 mol/L,it will inhibit CO_(2)absorption.Be‐sides,0.010 mol/L[Bmim][BF_(4)]+KBF_(4)absorbs the highest amount of CO_(2).The density functional calcula‐tion results demonstrate that[Bmim][BF_(4)]+KBF_(4)has a large K+volume and strong hydrogen bond force,and the solubility of K+in the ionic liquid is small,resulting in less steric hindrance,so[Bmim][BF_(4)]+KBF_(4)has more free volume to accommodate CO_(2).Overall,MILs have higher CO_(2)absorption than pure ILs,and have a better application prospects in greenhouse gases management.

关 键 词：CO_(2)吸收 碱金属盐 [Bmim][BF4]离子液体 金属络合离子液体 密度泛函计算 

分 类 号：X511[环境科学与工程—环境工程]