【作者】 邵可可；

【导师】 李希；

【作者基本信息】 浙江大学 ， 化学工程， 2007， 硕士

【摘要】 精对苯二甲酸(PTA)是聚酯工业的重要原料，主要采用对二甲苯(PX)空气液相氧化法生产。PX氧化得到粗对苯二甲酸(CTA)，再通过加氢精制得到精对苯二甲酸。本课题组对PTA生产工艺进行过长期的化学工程研究，掌握了该过程的氧化反应动力学，热力学，反应器流动与传递规律等过程信息，本论文在以上工作基础上，进行PTA全流程的模拟，开发包括氧化和加氢工序的全流程模拟软件，为过程开发和工业应用提供技术平台。论文对PTA过程中涉及的基础数据库进行了整理与完善，在此基础上建立了统一的单元数学模型，进而开发出基于联立方程法的并行流程模拟软件，模拟结果与工业运行数据吻合，最后对人机界面软件进行了开发。论文主要内容包括：◆PTA体系热力学数据库的整理与完善PTA体系内存在着相当复杂的多元热力学平衡关系，热力学数据库是单元模型的重要组成部分。本文利用HOC理论与UNIQUAC模型，建立了适用于气液、液液、汽液、液固多种相平衡计算的热力学数据库，回归得到了PTA生产体系中涉及到的13种主要物质的热力学模型参数，同时还提供了计算各相态混合物热焓的方法。◆统一单元模型的建立以往PTA流程模拟中一个常见的问题就是代码的可移植性不高，对于不同单元、不同体系，微小的改动都会导致模型、算法的全面变化。本文从一般的角度出发，对单级单元与多级单元分别进行了统一格式建模。充分利用各单元中普遍适用的质量守恒方程、相平衡方程、能量守恒方程，对单元参数与模型进行整理。◆PTA流程模拟算法的开发对于PTA体系内的各单元模型，利用联立方程的思想，采用Newton—Raphson方法进行求解。将求解的过程分解为求各单元方程残差与导数矩阵的模型端、求解Jacobi矩阵的服务端与定义流程的客户端。通过三者的有机结合，克服了原有的联立方程法中单元模型不能重用的缺点，使程序能够适用于各种要求下的计算。同时，充分利用稀疏矩阵的特点节省计算资源，提高计算速度。◆PTA流程模拟程序的界面开发对得到的PTA流程模拟程序进行了初步的界面开发，创建了友好的人机界面，使用户能够直观地进行输入与输出，详细地显示计算结果。更多还原

【Abstract】 Purified terephthalic acid (PTA), one of the main feedstock of polyester, is usually produced by liquid oxidization of p-xylene (PX). The byproduct, 4-carboxybenzaldehyd (4-CBA) is reduced by hydrogenating so that the purity of the product can achieve the industrial requirement. About this process, the mechanisms in reaction, phase equilibrium, gas-liquid mass transfer have been researched and mastered by our group. With all the knowledge, this paper will develop the software to simulate the whole process including oxidation and hydrogenation, and provide a basical platform for industrial application.Basical databases is supplied in this paper, mechanism models of all the units and the whole process are constructed which agree well with the industrial data. Advanced simultaneous equations method and parallel calculating are applied to simulate different PTA processes, and the interface of the program is developed, too.The thesis includes mainly following four parts.The Thermodynamic Databases of PTA ProcessThe thermodynamic databases are significant for mechanism models of units, while the thermodynamic equlibria of PTA process are complicated, including Vapor-Liquid\Gas-Liquid\Solid-Liquid\Liquid-Liquid equlibria in the same time. With HOC and UNIQUAC models, this paper provides databases to calculate all kinds of equilibria and enthalpy of PTA process which considers 13 materials. Necessary parameters are correlated and a good agreement is obtained.Mechanism Models of Units in PTA ProcessIn order to deal with the difficulty in reusing units models for different processes, with the mass conservation equations, energy conservation equations, and the thermodynamical equibria equations, etc, this paper conduct units models in the same uniform. Data structure is discussed to difine the function of units in process simulation, freedom is considered, too.PTA Whole Process SimulationBased on simultaneous equations, Newton-Raphson method is used to solve the large-scale nonlinear equations of the whole process. An advanced algorithm is also developed to calculate different processes, which with special structure of Client/Server/Models. Solution for sparse matrix and parallel calculating are applied, too.Interface of PTA process simulation programIn this part, the interface of the process simulation program is built to visualize the program, which is developed with Visual Basic. Visual input/output systems are constructed.更多还原