基于K-K方程的CO_2-离子液体吸收制冷工质对相平衡特性预测  

Prediction of phase equilibrium characteristics of CO_2-ionic liquid working pairs based on K-K equation

作　　者：彭丽 武卫东[1] 吴俊 汪力[1] PENG Li;WU Wei-dong;WU Jun;WANG Li(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093

出　　处：《高校化学工程学报》2019年第2期274-282,共9页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(51676129)

摘　　要：基于Krichevsky–Kasarnovsky(K-K)方程,首先通过将实验测得的溶解度数据与K-K方程相关联,得到不同温度下CO_2的亨利常数和无限稀释偏摩尔体积,然后运用改进的K-K(MKK)方程计算了温度为293.15～333.15 K及压力为0～5.0 MPa内CO_2在离子液体[emim][FAP]、[bmim][FAP]和[hmim][FAP]中的溶解度。结果表明:降低温度和升高压力都有助于提高CO_2的溶解度;同族离子液体阳离子的烷基链长度越长,CO_2的溶解度越大;当压力为5 MPa及温度为293.15 K时,CO_2在离子液体[hmim][FAP]中的溶解度值达到最大值为0.764 1;在相同条件下,CO_2在以上3种离子液体中的亨利常数与CO_2的溶解度大小次序相反,表明亨利常数越小,溶解度越大。由MKK方程计算得到的CO_2在3种离子液体中的溶解度值与实验值之间的总相对偏差绝对平均值分别为1.55%、2.09%和2.73%,表明MKK方程能以较好的精度预测CO_2在所研究离子液体中的溶解度。Henry's constant and partial molar volume of CO 2 at infinite dilution under different temperatures were obtained by correlating experimental solubility data with Krichevsky-Kasarnovsky (K-K) equation, and the solubility of CO 2 in ionic liquids (ILs)[emim][FAP],[bmim][FAP] and [hmim][FAP] was calculated using a modified K-K(MKK) equation at 293.15~333.15 K and 0~5.0 MPa. The results show that CO 2 solubility in the three ILs decreases with the increase of temperature but increases with the increase of pressure. Longer alkyl chains lead to higher CO 2 solubility. The solubility of CO 2 in [hmim][FAP] reaches the maximum value of 0.764 1 at 5 MPa and 293.15 K. Moreover, the Henry's constant of CO 2 in the above three ILs shows the opposite trend as that of CO 2 solubility under same conditions, which indicates that smaller Henry's constants means higher solubility. The absolute average values of total relative deviation between CO 2 solubility values in the three ILs calculated from MKK equation and the experimental values are 1.55%、2.09% and 2.73%, respectively, which indicates that the MKK equation can be used to predict CO 2 solubility in ILs.

关 键 词：溶解度 Krichevsky-Kasarnovsky 方程 亨利常数 偏摩尔体积 

分 类 号：O645.12[理学—物理化学]