含溶剂多组元相平衡的研究及应用

发布时间：2018-01-06 12:31

本文关键词：含溶剂多组元相平衡的研究及应用　出处：《天津大学》2015年硕士论文　论文类型：学位论文

【摘要】：相平衡是分离工艺开发、设备设计及流程准确模拟的理论基础。相平衡数据给出了平衡分离过程进行分离操作的极限,是多组元分离计算的基础。对于相对挥发度接近于1的难分离物系工业上通常采用特殊精馏(萃取精馏或共沸精馏等)的手段进行分离,其原理都是往混合物中加入溶剂,以增大各组分间的相对挥发度。因而,含溶剂的多组元体系相平衡数据对于此类难分离物系而言显得尤为重要。本研究中,利用汽液双循环相平衡仪,针对苯-噻吩和醋酸-水两组难分离物系,测定了加入相关溶剂后的多组元体系的汽液平衡数据,以期为其分离过程设计、工艺改进及流程模拟计算提供准确可靠的热力学基础数据。实验测定了101.33kPa下苯-噻吩、苯-二甲基亚砜(DMSO)和醋酸-醋酸仲丁酯(SBA)三个二元物系及苯-噻吩-二甲基亚砜、醋酸-醋酸仲丁酯-水两个三元体系的汽液平衡数据,丰富了苯-噻吩及醋酸-水两个待分离体系含溶剂的多元汽液平衡数据。测得的二元物系汽液相平衡数据均符合Herington面积法热力学一致性检验标准。选用NRTL和UNIQUAC活度系数模型对不含醋酸的二元物系实验数据进行热力学关联;对于含醋酸的体系,考虑到醋酸的强缔合性质,采用化学理论和HaydenO’Connell(HOC)相结合的方法对汽相的非理想性进行校正,选用NRTL-HOC和UNIQUAC-HOC模型进行关联;获得了相应的二元交互作用参数,温度偏差及组成偏差,结果表明两种模型均能较好的关联实验数据。利用二元物系UNIQUAC模型参数预测三元体系汽液平衡数据,预测值与实验值较为符合,平均偏差均在3%以内,获得了较好的预测结果,满足工程实际需求。此外,对醋酸-水体系的分离,在共沸精馏的基础上,提出一种萃取-共沸精馏集成的分离工艺。以醋酸仲丁酯为溶剂,通过间歇萃取实验对萃取段的可行性及模型参数的准确性、可靠性进行了验证;应用Aspen Plus流程模拟软件对集成分离工艺进行模拟优化,并以最低能耗为目标进行换热网络分析。在相同设备条件和设计规定下,分别以醋酸正丙酯和醋酸异丁酯为溶剂对分离过程进行模拟优化,得到最优能耗,进而对三种不同溶剂分离过程的能耗进行对比分析。
[Abstract]:The phase equilibrium separation process development, theoretical basis of equipment design and process simulation. The phase equilibrium data gives the equilibrium separation process for ultimate separation operation, the multicomponent separation calculation basis. The relative volatility of close to 1 are usually difficult to isolate the Department of industrial used special distillation (or extractive distillation were azeotropic distillation etc.) means of separation, the principle is adding solvent to the mixture, so as to increase the relative volatility between different components. Therefore, the multi-component systems containing solvent phase equilibrium data for such hard separation system is particularly important. In this study, the use of double circulating vapor-liquid equilibrium according to the instrument, thiophene and benzene - acetic acid water two group hard separation system, the vapor-liquid equilibrium data of multicomponent system added after the solvent was determined, in order for the separation process design, process improvement and process simulation for accurate The thermodynamic basis of reliable data. The experimental determination of 101.33kPa benzene and thiophene, benzene and two dimethyl sulfoxide (DMSO) - sec butyl acetate and acetic acid (SBA) three two yuan system and benzene and thiophene - two dimethyl sulfoxide, acetic acid sec butyl acetate - two three yuan water vapour liquid system equilibrium data, rich benzene and thiophene and acetic acid - water separation system to two solvent containing multiple vapor-liquid equilibrium data. Two yuan is measured by the vapor-liquid phase equilibrium data were fitted with Herington area method of thermodynamic consistency test standard. The choice of NRTL and UNIQUAC activity coefficient model were related to two yuan. Department of experimental data for containing acetic acid; acetic acid containing system, taking into account the strong association properties of acetic acid, the chemical theory and HaydenO Connell (HOC) method combining the non ideal phase correction of steam, using NRTL-HOC and UNIQUAC-HOC models were obtained corresponding relationship; The two element interaction parameters, composition and temperature deviation deviation, the results show that the correlation of experimental data of two kinds of model can better predict. Three yuan of vapor-liquid equilibrium data with two component system UNIQUAC model parameters, the predictive value is consistent with the experimental values, the average deviation is within 3%, obtain better prediction results and meet the actual needs of the project. In addition, the separation of acetic acid water system, on the basis of azeotropic distillation, put forward a kind of integrated extraction azeotropic distillation separation process. The SEC butyl acetate as solvent, the feasibility and accuracy of the model parameters on the extraction section of the intermittent extraction experiments, reliability has been verified the application of Aspen Plus process simulation software; simulation and optimization of integrated separation technology, and with the minimum energy consumption as the target of analysis of heat exchanger network. In the same conditions and provisions of equipment design, respectively, n-Propyl Acetate and vinegar The separation process was simulated and optimized by isobutyl ester as the solvent, and the optimal energy consumption was obtained. Then the energy consumption of three different solvent separation processes was compared and analyzed.

【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ028;TQ013.1

【相似文献】