基于非原始平均球近似理论的离子液体体系相平衡模型

The development of thermodyanmic model for system containing ionic liquids is one of the key research areas.In these studies, ionic liquids were assumed to be present as molecular species, and the electrostatic interactions between ions were not considered.In this program, the predictive model of phase equilibrium for system containing ionic liquids are establised on the basis of the non-primitive mean spherical approximation (MSA) approach by accounting for electrostatic interaction between ions and hard-sphere perturbation theory by accounting for the dispersion interaction with Cotterman et al.'s equation of state for a Lennard-Jones fluid.The specific content includes:(1) The phase equilibrium model for system containing ionic liquids is established. (2) The vapor pressure data are measured for water, 1-propanol, and 2-propanol as well as their binary mixtures with the ionic liuqid [EMIM][DEP].(3) The parameters for phase equilibrium model are confirmed through the equation of state for density of ionic liquids. (4) The established thermodynamic model is evaluated by calculating the measured vapor pressure data and other phase equilibrium data containing ionic liquids taken from literature.The establised thermodynamic model will provide theoretical basis for research and development of clean reaction-separation processes with ionic liquids.

含离子液体体系热力学模型的开发是当前研究的热点之一，但几乎都将离子液体作为中性分子处理，未考虑离子之间的静电作用。本项目拟用积分方程理论的非原始平均球近似描述离子-离子之间的静电作用，微扰理论描述基团之间的硬球和色散作用，并引入基团贡献的概念建立可以准确预测含离子液体体系相平衡的热力学模型。具体工作内容包括：离子液体体系相平衡预测模型的建立；含1-乙基-3-甲基咪唑磷酸二乙酯离子液体的正丙醇、异丙醇、水及其二元混合物体系相平衡数据的测定；通过离子液体密度性质的状态方程确定相平衡预测模型的参数；计算测定的汽液平衡数据，并扩展到文献上报道的其它含离子液体体系的汽液相平衡数据，验证模型的可靠性和通用性。为离子液体清洁反应分离过程的研究开发提供完善的理论基础。

本课题采用积分方程理论的非原始平均球近似描述离子-离子之间的静电作用，微扰理论描述基团之间的硬球和色散作用，并引入基团贡献的概念建立了可以准确预测含离子液体体系相平衡的热力学模型。首先建立了含离子液体体系相平衡预测模型。测定了含1-乙基-3-甲基咪唑磷酸二乙酯离子液体的正丙醇、异丙醇、水及其二元混合物体系相平衡数据。利用建立的离子液体密度性质 的状态方程对文献上报道的离子液体密度数据进行了关联和预测，建立了可靠的模型参数（基团的软球直径和色散能）数据库。基于建立的含离子液体体系相平衡模型和建立的模型参数数据库，对测定的汽液平衡数据以及文献上报道的汽液相平衡数据进行了计算。结果表明离子液体性质的模型和含离子液体体系的预测模型具有一定的合理性和可靠性，为离子液体清洁反应分离过程的研究开发提供完善的理论基础。