Start-up of Homogeneous Azeotropic Distillation Columns with Multiple Steady States

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• 作者：Nicolá ; s J. Scenna ; Sonia J. Benz ; Javier A. Francesconi ; and Né ; stor H. Rodrí ; guez
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2004
• 出版时间：January 21, 2004
• 年：2004
• 卷：43
• 期：2
• 页码：553 - 565
• 全文大小：215K
• 年卷期：v.43,no.2(January 21, 2004)
• ISSN：1520-5045

文摘

The impact of different start-up procedures on the behavior of two azeotropic distillation columnswith multiple steady states is analyzed. Several dynamic simulation results for the two studycases are presented. Through an examination of the profile evolutions corresponding to givenopen-loop start-up policies (manual start-up strategies), it can be seen how the column arrivesat different steady states as a function of the start-up policy. This shows that it is possible toidentify a set of critical values for supervision of the start-up. Also, guidelines of general validityare given with the aim of finding the appropriate start-up policy for obtaining a desired solution.A mechanistic (qualitative) approach is presented for the interpretation of the system behavior.Some connections among the system responses and the phenomenon of multiplicity are presented.Also, a quantitative, semiempirical relationship is introduced to corroborate the qualitativeexplanation of the system responses. Finally, closed-loop start-up policies using a simple PIcontroller are analyzed, showing that the desired steady state can always be achieved in thesecases.