Synthesis Design And Control Of Dividing Wall Columns Based On Batch Distillation

For batch distillation,its flexibility in operation and adaptability to special feed compositions and extreme conditions make it highly attractive.However,the significant energy consumption associated with batch distillation has been a major obstacle for its industrial application and is not aligned with the principles of sustainable development.Dividing wall column(DWC),as a promising energy-saving distillation technology,has emerged as a potential solution.Although there have been numerous studies on DWC and batch distillation individually,the research combining the two and exploring their dynamic control aspects is limited.Therefore,this study focuses on the feasibility and rationality of utilizing DWC technology for energy-saving purposes in batch distillation,using a case study of the separation of Benzene,toluene,and xylene(BTX)ternary system.The investigation covers dynamic response,distillation time,and energy consumption aspects.(1)This study selected three DWC configurations,namely,Top Dividing Wall Column(TDWC),Middle Dividing Wall Column(MDWC),and Bottom Dividing Wall Column(BDWC).Batch distillation was employed as the operating mode,and rational composition control systems and temperature control systems were designed based on the distinctive process characteristics of each configuration.The results demonstrate that both temperature control and composition control schemes can achieve the desired separation task,with temperature control exhibiting superior performance in terms of dynamic response and energy consumption.(2)This study includes a classic improved batch distillation structure,Middle Vessel Batch Distillation(MVD),as a control group to accomplish the separation task.The comparison with the aforementioned three DWC column structures reveals that BDWC performs the best,thereby demonstrating the superior economic and energy-saving advantages of applying DWC technology to batch distillation over traditional batch distillation column structures.Moreover,BDWC exhibits better performance in the context of batch distillation.This study focuses on the investigation from the perspective of dynamic simulation and control system design,using an actual separation case as the basis.A comparative analysis of the four structures is conducted in terms of control performance,distillation time,and energy consumption.The feasibility and effectiveness of employing batch DWC structures in practical production are demonstrated,and the more advantageous DWC structure is identified.The underlying reasons and mechanisms behind the experimental results are analyzed.This research provides valuable insights and practical significance for the further exploration and industrial application of batch DWC,thereby contributing to the green chemical industry and sustainable development in China.It holds significant research value and practical implications.