Design Of Reactive Dividing Wall Distillation Column: Separation Of More Unfavorable Reactant System

For the separation of chemical reactant systems with unfavorable thermodynamic properties(that is,the reactants are the lightest and heaviest components,and the products are the light and heaviest components),the introduction of external circulation between the top of the reactive distillation column and the reaction section can improve the thermodynamic efficiency of the system,the reduction of equipment investment costs and operation energy consumption,thereby obtaining the top-middle external loop reaction distillation column.On this basis,the introduction of partition wall technology is still possible to improve the steady-state performance of the system.In this paper,the design of the Reactive Dividing-Wall Disitillation Column(R-DWDC)is studied for the above-mentioned reactants.First of all,this article presents four possible R-DWDC topological structures,and builds a steady-state model of R-DWDC.Taking the quaternary ideal reactant system as the research object,combining the reactant overfeeding technology and the partition wall technology,the separation problem of the more unfavorable reactant system is solved.Using Aspen Plus software to establish simulation models of four R-DWDC topological structures and conduct comprehensive design,obtain the optimal R-DWDC design of different topological structures.The results show that the reaction separation wall distillation column can effectively solve the reaction separation problem of the more unfavorable reactant system,and R-DWDCⅡ with excessive feed of the lightest reactant has higher steady-state performance.Secondly,this article studies the dynamic characteristics and controllability of R-DWDC for the separation of ideal quaternary reactant systems,and designs a decentralized control scheme based on steady-state design.The simulation results show that the product output concentration can return to the set value in a short period of time when the feed flow and composition are greatly disturbed.The decentralized control scheme can effectively suppress the influence of interference,and the system has a good performance.Dynamic performance.In summary,R-DWDC has higher steady-state performance and better dynamic characteristics when the chemical reactant system with low conversion rate and unfavorable thermodynamic characteristics is reacted and separated.