A Short Note on Control Structures for Thermally Coupled Distillation Sequences for Four-Component Mixtures
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- 作者：Salvador Herná ; ndez ; Ivá ; n R. Gudiñ ; o-Mares ; J. Carlos Cá ; rdenas ; Juan Gabriel Segovia-Herná ; ndez ; and Vicente Rico-Ramí ; rez
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2005
- 出版时间：July 20, 2005
- 年：2005
- 卷：44
- 期：15
- 页码：5857 - 5863
- 全文大小：435K
- 年卷期：v.44,no.15(July 20, 2005)
- ISSN：1520-5045
文摘
Thermally coupled distillation represents an alternative to conventional distillation to separatemulticomponent mixtures. Industrial implementation of those systems can be achieved by usingthe divided-wall distillation column. It has been proven that a savings of up to 30% in the totalannual costs can be obtained with these complex distillation sequences. In a previous work byCárdenas et al. (Cárdenas, J. C.; Hernández, S.; Gudiño-Mares, I. R.; Esparza-Hernández, F.;Irianda-Araraujo, C. Y.; Domínguez-Lira, L. M. Analysis of Control Properties of ThermallyCoupled Distillation Sequences for Four-Component Mixtures. Ind. Eng. Chem. Res. 2005, 44,391-399), it was found that thermally coupled distillation sequences not only can provide savingsin the total annual costs but also can present good dynamic responses under closed-loop operationin contrast to distillation sequences based on conventional columns. In the previous study,pairings in the control loops were established according to practical considerations, i.e., distillatecomposition-reflux rate, bottoms composition-reboiler heat duty, and side-stream purity-flowrate. As a result, in this work some new pairings in the control loops, obtained by using therelative gain array, were tested in order to improve the dynamic responses of the thermallycoupled distillation sequences for the separation of quaternary mixtures of hydrocarbons. Theresults showed that the dynamic responses were improved significantly for the case of changesin the set points. As a result, savings in total annual costs can be achieved without introducingcontrol problems.