Optimization And Experimental Study Of Vertical Double Wall Dividing-wall Column For Separating A Quaternarysystem

Distillation is one of the most mature and extensive technologies in contemporary chemical production.As a hot spot of research in the trend of equipment integration and equipment strengthening,the dividing wall column is being applied rapidly in industrial equipment.The dividing wall column is mainly used for the separation of the multi component system.At present,the research on the separation of three component mixtures by using the DWC has been relatively mature at home and abroad.There are few reports on the separation of four or more components.On the basis of summarizing the past research,a vertical double wall divided-wall column separating four-component mixture was proposed,which provided a kind of new structure for the separation process of four component.The following research has been done for this new type of DWC.In view of the traditional three tower process and kaibel column,the separation of the four component mixture has high energy consumption,high equipment cost,large occupied area,the high main tower section and the difficulty of controlling the spilt vapor ratio.A vertical double wall divided-wall column separating four-component mixture was proposed and the structure design of the tower was introduced and explained in detail.According to the structure and separation principle of the new divided-wall column,the five-tower model was designed and conducted a shortcut design calculation.Based on the separation system of n-Pentane-n-Hexane-heptane-N-octane,the process of VDWDWC was simulated using the process simulation software-Aspen plus.The separation effect and energy consumption of VDWDWC and kaibel column and the traditional three-column processes were compared.The effects of the feeding position of VDWDWC,the reflux ratio of the top of the tower,the position of the wall and the spilt liquid or vapor ratio on the separation effect and the energy consumption of the products were investigated.The sequential two-stage method was used to optimize the conventional three-column process and the VDWDWC by using pentane,hexane,heptane and octane as separators,and the annual total cost(TAC)was calculated.The VDWDWC experimental device was designed and built by ourselves.The effect of factors such as the reflux ratio at the top of the column,spilt liquid ratio,the flow rate of the main column and the feed composition on the separation effect and the temperature distribution on both sides of the wall were investigated through experiments.