Double Divided Wall Distillation Column For Separating Somewhat Favorable System

External recycle reactive distillation column has proved to facilitate forward reaction to a certain extend for separating somewhat favorable system.However,it does not fully consider the coupling of substances and energy,the optimum separation effect cannot be achieved,energy efficiency and economic benefits still have room to be promoted.Therefore,it is necessary to further explore the optimal structural of distillation column.In order to solve the problems of high energy consumption and high investment cost in the ER-RDC,this paper proposes the configuration by combining process intensification and presents a variety of DWDC with different coupling degrees.Firstly,the two separated sequences of ER-RDC are coupled to form RDC+DWDC.On this basis,the structure of double dividing wall distillation column was obtained by coupling the RDC,and two configurations of DDWDCI(the right wall is located at the top of the column)and DDWDCII(the right wall is located at the middle of the column)are formed during the discussion on the position of dividing wall.In this paper,configurations of RDC+DWDC,DDWDCI and DDWDCII are designed respectively.The economic index TAC is taken as the objective function to optimize each steady state structure.The optimum structure of CRDC and ER-RDC are taken as basis reference model,the conclusion is drawn after analyzing and comparing the steady state performance of five structures,the DDWDC II with the highest coupling degree achieves the optimal performance,for somewhat favorable reactant system,the reaction rate is proved,the operating cost is by 50%and 50.2%respectively,and the TAC is reduced by 43.7%and 47.2%,which obtains the best steady state performance.Meanwhile,under the four-point temperature inference control strategy,when the system is confronted with the disturbance of ±20%changes in feed flow rate,DDWDCII can also obtain better dynamic characteristics.It is fully proved that DDWDCII is the optimum structure of separating somewhat favorable system.It is also confirmed that the steady state performance of distillation column enhances with the increases of coupling degree.