离子强度智能开关溶剂-有机物体系的相平衡热力学及其应用研究

Intelligent switchable solvents with ionic strength are a green solvent which can replace traditional volatile solvent to extract useful components from solid materals and replace inorganic salt in salting-out process. Application of intelligent switchable solvents with ionic strength will reduce the energy consumption of the production process, diminish the pollution of volatile solvents on the environment and avoid producing the waste water containing salt. As a result it becomes the object of green chemistry technology. The key factor for application of intelligent switchable solvents with ionic strength to the industrial process is the phase equlibrium thermodynamics for intelligent switchable solvents with ionic strength-organic compounds systems.The project is to investigate the phase equilibrium of tetrahydrofuran, acetonitrile, pyridine, 2-methylimidazole, chymotrypsin and lysozyme in switchable solvents with various ionic strength, construct the corresponding phase diagram of multi-component system, and establish the thermodynamic model of the phase equilibrium for the system, acquire the relationship between the corresponding model parameters and ionic strength and polarity in solutions. Based on the phase equilibrium thermodynamics and phase diagram, we study the extraction process and crystallization process for organic compounds, and analyze the influence of ionic strength on the yield of organic compounds and crystal morphology and activity for protein, and investigate the influencing factors of additive residues in product, and obtain the optimum process conditions. The completion of the project can provide a theoretical basis for the application of intelligent switch solvent with ionic strength in the valuable component extraction from solid materials and the green salting-out process. The project is of important academic value and practical significance and has a broad application prospects.

以离子强度智能开关溶剂代替传统的易挥发性溶剂萃取固体中的有效成分以及代替盐析过程中的无机盐，可以大大降低生产过程的能耗、减少易挥发性溶剂对环境的污染和避免含盐废水的产生，是绿色化学发展的方向。其应用到工业过程的关键是离子强度智能开关溶剂-有机物的相平衡热力学。本项目研究四氢呋喃、乙腈、吡啶、2-甲基咪唑、α-糜蛋白酶和溶菌酶等在不同离子强度智能开关溶剂中于不同离子强度下的相平衡，绘制相应的平衡相图，建立体系的相平衡热力学模型，得到相应的模型参数及其与离子强度和溶液极性的关系。探讨有机物的萃取分离和结晶工艺，分析离子强度的变化对有机物的收率以及蛋白质结晶形态和活性的影响，考察添加剂在产品中残留量的影响因素,得到较为为适宜的工艺条件。该项目为离子强度智能开关溶剂在萃取固体中的有效成分和绿色盐析过程中的应用提供理论依据，具有重要的学术价值和现实意义，有着广阔的应用前景。

本项目系统开展了离子强度智能开关溶剂体系的相化学和热力学性质研究，测量了283.15-308.15 K 温度范围内N,N二甲基环已胺/三乙胺/N,N二甲基苄胺-二氧化碳-水体系的密度、粘度、折光率和电导率，采用两种经验模型关联了体系密度、粘度、折光率和电导率与温度和组成的关系，根据物性数据，计算了溶液的表观摩尔体积、标准偏摩尔体积、相对粘度、粘度B系数；测定了三元体系(DMCAH-bicarbonate/TEAH-bicarbonate/BDMAH-bicarbonate + toluene/acetonitrile/THF/pyridine/1,3-dioxolan+水)在常压不同温度(15,25,35℃)下的液液相平衡数据。实验数据用Othmer-Tobias方程进行可靠性关联,关联结果表明数据的可靠性较好,根据实验结果绘制了三元相图。对不同温度下的液液平衡实验数据,用e-NRTL活度系数方程进行了关联,求得方程的二元交互作用系数,关联结果表明e-NRTL方程对该体系适用较好。由实验数据计算得到衡量有机物抽提性能的参数(分配系数、选择性系数)。 这些结果为开关溶剂体系在化工分离中的应用提供了重要的信息。