CO_2在醇中溶解度的测定与分子连接性指数的关联

Measurement of the Solubility for CO_2 in Alcohols and its Correlation with the Molecular Connectivity Index

用恒定溶剂法测定了303.15K下CO2在乙醇、正丙醇、异丙醇、正丁醇、正戊醇、异戊醇、正己醇、正辛醇、乙二醇、1,2-丙二醇中的溶解度。实验表明:随着碳链的增长,吸收CO2的效果越好,CO2在正辛醇中的溶解度最大,CO2在二元醇中的亨利常数显著大于一元醇。利用线性回归方法建立CO2在醇中的亨利常数lgH与分子连接性指数的相关关系模型,模型计算简单易行,对CO2在醇中的亨利常数有良好的估算和预测能力,相关系数R>0.99,计算值和实验值吻合良好。研究表明:用一阶分子连接性指数1χv、羟基的个数N、经验参数COH三个参数可以描述CO2在醇中的溶解特性lgH,且精确度很高。

The solubility of CO2 in ethanol,propanol,isopropanol,butanol,amyl alcohol,isoamyl alcohol,hexanol,octanol,ethylene glycol and 1,2-propanediol were experimentally determined by the constant volume method at 303.15 K.The results show that the solubility of CO2 in above solvents increase with increasing the carbon-chain length in the alcohols,and the solubility of CO2 in octanol is the largest.It was found that the Henry＇s law constant of CO2 in diolis is significantly greater than that in monohydric alcohol.Using the linear correlation method,the Henry＇s law constant was correlated with MCI（Molecular Connectivity Index） and the correlated model could predict the Henry＇s law constant and the solubility of CO2 in alcohols well with the relative coefficient R〉0.99.The study also shows that using the first order MCI 1χv combined with the number of hydroxyl N and empirical parameters COH could satisfactorily predict the solubility of CO2 in alcohols mentioned above with very high accuracy.