Feasibility of Ternary Reactive Distillation Systems： Decomposition Reaction

• Main Authors: Chin-Shin Chen, 陳晉仕
• Other Authors: Cheng-Ching Yu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/24913219760483127384

碩士 === 國立臺灣大學 === 化學工程學研究所 === 95 === Abstract The reactive distillation offers significant economic advantages in some systems, especially when reactions are reversible and/or when azeotropes are presented. The feasibility analysis helps us to check whether a process is feasible or not. It is crucial and important because there are fewer methods for shortcut designs and the iterative design is always time-consuming in reactive distillation column. A lot of time would be saved for the design procedures of reactive distillation by getting rid of infeasible cases and focusing on the feasible ones. Systematical research on feasibility analysis of ternary azeotropic systems has been done by Guo et al (Guo et all, 2004). The analysis method they used is tray-by-tray calculations with difference point. There are two feasibility criteria, which are positive reaction extent is required and products can be reached by distillation or reactive distillation. In this work, we find that the feasibility analysis of reactive distillation in this method can be augmented by admitting the reverse reaction which can be demanded by excess positive reaction. And two conecepts which could be used to accelerate the feasibility analysis are shown. The first one is that vectors at equilibrium line and tray-by-tray calculations method with difference point are equivalent in feasibility analysis. And pinch points of tray-by-tray calculations under chemical equilibrium and infinite reflux ratio is just the reactive azeotrope. The number of feasible cases are increased from 27 to 48 in 113 all possible ternary configurations. Nine cases are feasible with low equilibrium constants, and twelve cases could be feasible with proper equilibrium constants. Those results are compared well with reactive distillation column simulations. Design and control of ternary ideal system, A↔B+C, are also be explored. Better design, both on economical and energy saving, could be found by using the result of feasibility analysis. And the designs are shown to be workable in dynamic.