Steady State Design and Economic Analysis of Divided Wall Columns

• Main Authors: Kai-Ti Chu, 朱愷悌
• Other Authors: Jeffery Ward
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/99012108297020535269

碩士 === 臺灣大學 === 化學工程學研究所 === 98 === Divided-wall columns (DWCs) can save energy and capital cost compared with traditional distillation columns. However the design of DWCs is more difficult because there are more degrees of freedom. This work provides a novel shortcut method that can be used for the design of three types of DWCs. A rational and efficient net flow model is constructed to describe DWC systems. The development of the method is based on dividing the DWC into several parts and applying the methods of Fenske-Underwood-Gilliland and the Kirkbride equation. A series of rigorous simulations are applied to two real systems in order to show the performance. The results show that the total annual cost (TAC) based on the design method is close to the minimum total annual cost. This method also provides good initial values for rigorous optimization. In economic analysis, this method is applied to calculate the total annual cost for different Ease of Separation Index (ESI) and different feed composition for three types of DWCs. Finally, the criterion of the choice of DWCs is presented according to TAC. However the control aspect should also receive attention, because of the vapor split disturbance problem for DWCM and DWCU. For an equivalent TAC, it is suggested to use DWCL according to this operating consideration. The steady state design and economic analysis for three types of DWCs in different feed condition are investigated in this work.