Distillation Dynamics: Propagation and Fate of Disturbancesin Multicomponent Fractionation Columns

该项目旨在开发一个现象学模型来描述多组分系统的精馏塔动力学。为了改进精馏塔的实际设计和控制，该模型恰当地描述了精馏塔动力学的临界非线性和分布性，其数学框架足够简洁，可用于在线控制(如前馈控制器)、控制系统分析和精馏塔设计。最终目标是使精馏塔能够在较低的回流比下操作，从而降低能源消耗。更好地从根本上了解色谱柱动力学将使升级现有色谱柱和设计对干扰不那么敏感的新色谱柱成为可能。研究方法是基于简单逆流分离过程的多组分相干理论，如固定床层析理论。通过包括回流和再沸腾的动力学、两个或多个截面之间的相互作用以及热效应来扩展该理论。通过与实验结果的对比，验证了理论和动力学模型的正确性。实验是在工业实验室中进行的，中试规模的计算机控制蒸馏塔配有快速气相色谱系统，用于在线成分监测。

The project aims at developing a phenomenological model for describing distillation-column dynamics for multicomponent systems. For improving practical design and control of fractionation columns the model appropriately describes the critical nonlinear and distributed nature of column dynamics with a mathematical framework which is concise enough for on- line control (e.g. feed forward controllers), control system analysis, and column design. The ultimate goal is to make distillation columns operable at lower reflux ratios, and thus to lower energy consumption. Better fundamental understanding of column dynamics will make it possible to upgrade existing columns and design new ones which are less sensitive to disturbances. The research approach is based on the multicomponent coherence theory of simpler countercurrent separation processes such as fixed-bed chromatography theory. The theory is expanded by including the dynamics of reflux and reboil, interaction between two or more sections, and heat effects. The theory and the dynamic model are tested by comparison with experimental results. Experiments are carried out in an industrial laboratory with a pilot-plant-scale, computer controlled distillation column properly equipped with a fast gas chromatography system for on-line composition anonitoring.