吸收—水合复合法分离低碳混合气体的过程模拟与优化

发布时间：2018-02-24 02:10

本文关键词： 水合物动力学流程建模收敛方法经济性评价全局优化方法　出处：《天津大学》2016年博士论文　论文类型：学位论文

【摘要】：本论文针对催化裂化干气和催化裂解气低能耗分离低碳烯烃的需求,结合较高浓度油吸收效率高、较低浓度水合效率高的优势,开发了一种用于分离低碳气体混合物的吸收-水合复合工艺。现有的流程模拟软件中均没有关于水合物的物性计算方法,为了模拟和评估所开发的流程,本文参考现有的热力学理论,在方程导向的建模环境中编写了多相相平衡计算程序,并根据动力学实验的结果,使用时间正交离散的方法,拟合了乙烯水合动力学参数。以动力学和热力学模型为基础,建立了水合操作单元的模型,并将模型成功地链接到流程模拟软件中;在流程模拟软件中构建了整个吸收-水合复合流程,以经济性评估为参考,优化了流程操作条件。计算结果表明,吸收-水合流程的年平均费用比传统吸收法低12%;同时发现,虽然水合物能够有效回收低浓度的C2,但是对于高浓度的C2,由于其内部的大小孔结构,水合物并不能提供较高的选择性。最后,针对大规模流程高效模拟的需求,讨论了化工系统工程的发展方向,包括更先进的建模工具、全局优化、计算容错和并行计算等,提出了一种实现热耦合流程全局优化的框架,该框架包括并行的全局优化算法、简化的操作单元模型、帮助流程收敛的渐变边界法以及挟点分析等内容,该框架适用于优化复杂的热耦合系统。
[Abstract]:In this paper, according to the demand of FCC dry gas and catalytic cracking gas for low energy consumption separation of low carbon olefin, combined with the advantages of higher oil absorption efficiency and higher hydration efficiency. An absorption-hydration composite process for the separation of low-carbon gas mixtures has been developed. There are no methods for calculating the physical properties of hydrates in existing process simulation software. In this paper, referring to the existing thermodynamic theory, a multiphase equilibrium calculation program is written in the equation-oriented modeling environment. According to the results of the kinetic experiments, the method of time orthogonal discretization is used. Based on the kinetic and thermodynamic models, the model of hydration unit was established, and the model was successfully linked to the process simulation software. The whole absorption-hydration complex process was constructed in the process simulation software, and the operating conditions were optimized with the economic evaluation as the reference. The calculation results show that the annual average cost of the absorption-hydration process is 12% lower than that of the traditional absorption method. At the same time, it is found that, Although hydrates can recover low concentration of C _ 2 effectively, for high concentration C _ 2, hydrates can not provide high selectivity due to their internal macroporous structure. This paper discusses the development direction of chemical engineering, including more advanced modeling tools, global optimization, computational fault tolerance and parallel computing, and proposes a framework for global optimization of thermally coupled processes, which includes parallel global optimization algorithms. The simplified operation unit model, the gradient boundary method to help the convergence of the process and the analysis of the carrying point, etc., are suitable for the optimization of complex thermal coupling systems.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TQ028.1

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