Design and Control of Various Heterogeneous Azeotropic Distillation Systems and Divided-Wall Column Processes
| Autor: | Yi-Chang Wu, 吳義章 |
|---|---|
| Rok vydání: | 2014 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 102 The design and control of three dehydration process systems via heterogeneous azeotropic distillation and dividing-wall column design will be investigated in this thesis. In the first part, the azeotropic distillation system to separate out methyl methacrylate (MMA) from a mixture including methyl methacrylate, methanol, and water is studied. In this work, a simple design &;#64258;owsheet is devised with a distillation column, a bottom decanter, and a stripper. This column/decanter/stripper design can further be simpli&;#64257;ed into an even simpler design &;#64258;owsheet with only one distillation column with sidedraw and a middle decanter. Optimal design and dynamic control of this simpli&;#64257;ed separation process are investigated in this report. It is shown that the product purity speci&;#64257;cations can be maintained despite feed disturbances by holding a tray temperature above the sidedraw location and another one below the sidedraw location. In the second part, energy-saving potential of heterogeneous azeotropic dividing-wall columns are investigated via a demonstrating example for the separation of pyridine and water using toluene as entrainer and another example of 1,4-dioxane dehydration process with small amounts of triethylamine (TEA) impurity. By comparing the optimized design of this dividing-wall column with the original design, significant reduction in the reboiler duty can be obtained. Furthermore, because two important control degree-of-freedoms are still preserved in the dividing-wall column, no hampering of the control performance can be observed. In the last part, we discuss the dynamics and control of heterogeneous azeotropic distillation column with two different decanter configurations. The main difference of these two configurations is the layout after condensing top vapor stream. For the first design, top vapor stream will go directly into a decanter. For the second design, top vapor stream will go into reflux drum and then the distillate stream goes into a decanter. In the thesis, we will investigate the proper overall control strategy for these two configurations. Overall control strategy of the first design is proposed with dual-temperature control loops. Large perturbations of the feed composition can be handled. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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