咪唑类离子液体对低压丙酮蒸气吸收性能研究

发布时间：2018-04-11 23:34

本文选题：低压吸收 + 气液平衡　；参考：《南京大学学报(自然科学)》2017年06期

【摘要】：在303.2~333.2K范围内,采用三釜气液平衡系统测量丙酮与5种咪唑类离子液体的二元气液平衡数据.然后采用非随机(局部)双液体模型(NRTL)关联二元体系的等温气液平衡.最后基于模型,获得了丙酮蒸气在离子液体中的无限稀释活度系数和亨利系数,并评价了吸收过程的Gibbs自由能、焓变、熵变和偏摩尔过量焓变等热力学性质.实验表明,亨利系数随着温度升高而增大,丙酮的无限稀释活度系数均小于1,混合溶液为负偏差溶液,利于丙酮的吸收.延长阳离子侧链烷基长度可缓慢提高丙酮溶解度,但相对于阳离子而言,阴离子对丙酮溶解度影响较大,且按如下顺序递增:[BF4][PF_6][Tf_2N].热力学分析表明丙酮吸收由体系的熵变控制.[Tf_2N]类离子液体吸收熵变值较大,混合溶液热力学稳定性高,与丙酮分子间作用力强,对丙酮溶解性能强.
[Abstract]:The binary gas-liquid equilibrium data of acetone and five kinds of imidazole ionic liquids were measured by using a three-vessel gas-liquid equilibrium system within the range of 303.2 ~ 333.2K.Then the isothermal vapor-liquid equilibrium of binary system is correlated by using a non-random (local) two-liquid model (NRTL).Finally, the infinite dilution activity coefficients and Henry's coefficients of acetone vapor in ionic liquids are obtained, and the thermodynamic properties of the absorption process such as Gibbs free energy, enthalpy change, entropy change and partial molar excess enthalpy change are evaluated.The results show that the Henry coefficient increases with the increase of temperature, the infinite dilution activity coefficient of acetone is less than 1, and the mixed solution is a negative deviation solution, which is propitious to the absorption of acetone.Prolonging the alkyl length of cationic side chain can increase the solubility of acetone slowly, but the anion has a great influence on the solubility of acetone compared with cationic ion, and increases in the following order: [BF4] [PF_6] [Tf_2N].The thermodynamic analysis shows that the absorption of acetone is controlled by the entropy change of the system. [Tf_2N] ionic liquids have large absorption entropy variation, high thermodynamic stability of mixed solution, strong interaction with acetone molecules, and strong solubility to acetone.
【作者单位】：江苏瑞达环保科技有限公司;南京大学盐城环保技术与工程研究院;南京大学化学化工学院;
【基金】：国家自然科学基金(91634104,21476105) 江苏省产学研项目-前瞻性联合研究项目(BY2016068-03)
【分类号】：O642

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