离子强度智能开关溶剂—有机物体系相平衡热力学研究

发布时间：2018-07-10 17:20

本文选题：开关溶剂 + N　；参考：《扬州大学》2017年硕士论文

【摘要】：本文研究的离子强度智能开关溶剂体系是在水中加入N,N-二甲基环已胺(DMCA)或三乙胺(TEA)。N,N-二甲基环已胺和三乙胺都是是疏水性叔胺,在分子状态时,疏水性叔胺不溶于水,而向其水溶液中通入C02后变为离子形式的碳酸氢盐([HC03]-),与水形成均相体系,溶液的离子强度大大增加。当向体系中通入N2或加热的情况下[HCO3]-又会变为胺,溶液的离子强度几乎接近于零。正是这种离子强度的可逆性,使得离子强度智能开关溶剂在有机物-水体系中回收水溶液中的有机物质、盐析萃取等方面有着较为广阔的应用前景。离子强度智能开关溶剂各项物性、相平衡等热力学数据的缺乏使其在分离过程中的实际应用遇到一些困难,本文主要研究了离子强度智能开关溶剂的物化性质及离子强度智能开关溶剂-有机物-水体系的液-液相平衡,为其在工业中的应用提供了基础数据和理论依据,具有较高的理论价值和工业应用价值。具体完成了以下几个方面的工作:(1)采用重量法测定DMCA-水体系吸收C02后,生成[DMCAH][HC03](N,N-二甲基环已胺碳酸氢盐)的速率。使用乌氏粘度计,振动式比重计测定水相的粘度和密度两种基本物性,并用核磁共振C13谱进行表征。考察了温度、DMCA与水的体积比等因素对DMCA吸收C02速率的影响。将实验测得的粘度和密度数据用Vogel-Tamman-Fulcher方程进行关联,平均相对偏差(ARD)和标准偏差(SD)值都较小,效果较好。再用实验测得的密度数据计算出[DMCAH][HC03]溶液的表观摩尔体积。(2)选用DMCA和TEA两种离子强度亲水性可切换开关溶剂,测定了 298.15K、303.15K、308.15K三个温度下四个三元体系(水+ DMCA +甲苯;水+ TEA 十甲苯;水+[DMCAH][HC03]+甲苯;水+[TEAH][HC03](三乙胺-碳酸氢盐)+甲苯)液-液相平衡数据,绘制相应的三元液-液平衡相图。选用Othmer-Tobias方程检验了实验数据的可靠性,该方程对四个三元体系在不同温度下的液-液相平衡数据关联精度R2均接近于1,证实了所测定实验数据的准确性。采用NRTL液-液相平衡模型对四个三元体系进行关联,得到的计算值与实验值吻合,效果较好。该实验数据为离子强度智能开关溶剂分离回收水溶液中的有机物提供了热力学基础。(3)以TEA作为智能离子强度开关溶剂,测定298.15K、303.15K、308.15K三个温度下两个三元体系(TEA十水+1,3-二氧五环;[TEAH][HC03]+水+1,3-二氧五环)液-液相平衡数据,绘制相应的三元液-液平衡相图。选用Othrmer-Tobias方程对实验数据进行可靠性验证,回归得到的线性相关系数均大于0.99,验证了数据的可靠性。再用NRTL液-液相平衡模型进行关联,实验值与模拟值的均方根偏差(RMSD)比较小,说明了关联效果较好,精确度比较高,也为亲水性可切换离子强度智能开关溶剂的盐析萃取工艺提供了理论基础。
[Abstract]:In this paper, the ionic strength intelligent switch solvent system is to add N, N- two methyl cyclohexylamine (DMCA) or three ethylamine (TEA).N, N- two methyl cyclohexylamine and three ethylamine are hydrophobic tertiary amines, and at molecular state, hydrophobic tertiary amines are insoluble in water, and they turn into the water solution into ionic form of the bicarbonate ([HC03]-) in the water solution. In the homogeneous system with water, the ionic strength of the solution increases greatly. When N2 or heating is used in the system, the [HCO3]- becomes amines, and the ionic strength of the solution almost approaches zero. It is the reversibility of the ionic strength to reclaim the organic matter in the aqueous solution by the ionic strength intelligent switch solvent. There is a broad application prospect in salting out extraction. The lack of thermodynamics data such as ionic strength intelligent switch solvent and phase equilibrium make it difficult to apply in the process of separation. In this paper, the physical and chemical properties of ionic strength intelligent switch solvent and the solvent of ionic strength intelligent switch are studied in this paper. The liquid liquid equilibrium of the material water system provides basic data and theoretical basis for its application in industry. It has high theoretical value and industrial application value. The following work has been completed: (1) the determination of C02 by the gravimetric method for the absorption of DMCA- water system to [DMCAH][HC03] (N, N- two methyl cyclohexane bicarbonate) Rate. Using the wulson viscometer, two basic properties of the viscosity and density of water phase are measured by a vibratory hydrometer, and the C13 spectra are used to characterize the water. The influence of the temperature, the volume ratio of DMCA and the volume of water on the C02 rate of DMCA absorption is investigated. The viscosity and density measured by the experiment are correlated with the Vogel-Tamman-Fulcher equation. The relative deviation (ARD) and the standard deviation (SD) value are small and the effect is better. The apparent molar volume of [DMCAH][HC03] solution is calculated with the density data obtained by the experiment. (2) four three elements (water + DMCA + toluene) under the three temperatures of 298.15K, 303.15K and 308.15K are determined by using two kinds of ionic strength hydrophilic switching solvents of DMCA and TEA; Water + TEA ten toluene, water +[DMCAH][HC03]+ toluene, water +[TEAH][HC03] (three ethylamine - bicarbonate) + toluene, liquid liquid equilibrium data, draw a corresponding three element liquid liquid equilibrium phase diagram. The reliability of the experimental data is tested by using the Othmer-Tobias equation, and the equation is related to the liquid liquid equilibrium data of the four three body systems at different temperatures. The degree R2 is close to 1, which confirms the accuracy of the measured data. The NRTL liquid liquid equilibrium model is used to relate the four three element systems. The calculated values are in good agreement with the experimental values. The experimental data provide a thermodynamic basis for the organic matter in the solvent separation and recovery of the aqueous solution by the ionic strength intelligent switch. (3) TEA as the basis. For the intelligent ion intensity switch solvent, two three elements (TEA ten water +1,3- two oxygen ring, [TEAH][HC03]+ water +1,3- two oxy ring) liquid liquid equilibrium data were measured at three temperatures of 298.15K, 303.15K and 308.15K, and the corresponding liquid liquid equilibrium phase diagram was drawn. The reliability of the experimental data was verified by the Othrmer-Tobias equation, and the regression was obtained. The linear correlation coefficient is more than 0.99, which validates the reliability of the data. The correlation is used by the NRTL liquid liquid equilibrium model. The experimental value is smaller than the mean square deviation (RMSD) of the simulated value. It shows that the correlation effect is better and the accuracy is higher. It also provides a reasonable solution for the salting out extraction process of the hydrophilic switching ionic strength intelligent switch solvent. On the basis.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O642.42

【参考文献】