Study On The Combination Of Continuous Distillation And Extractive Distillation To Extract Diethylbenzene From C₁₀ Aromatics

The origin,production status,use and highly processing technology situation of C10 arenes were summarized in this paper.The resources of diethyl benzene was rich in our country.If diethyl benzene isomers can be separated,not only the use expanded,but also the value of product added.The method which combined continuous distillation and extractive distillation was adopted to refine the diethyl benzene fraction from C10 arenes after comparing the method of separating diethyl benzene at home and abroad.The method of continuous distillation was firstly adopted to refine diethyl benzene mixtures.The process was simulated by Aspen Plus,and the conditions of simulation such as top product ratio,column plate number,feed position and reflux ratio were studied.The once experimental apparatus of continuous distillation was established on the basis of best simulation data.The experimental results showed the purity of diethyl benzene mixture at the top was 65.83%with the yield of 77.26%,under the conditions of that tower height was 160cm,feed position was 80cm,feeding speed was 3g/min,distillation flow rate was 0.57g/min and reflux ratio was 5.The second experimental apparatus was also established.The results showed the purity of diethyl benzene mixture at the bottom was 78.23%with the yield of 93.88%,under the conditions of that tower height was 200cm,feed position was 90cm,feeding speed was 3g/min,distillation flow rate was 0.63g/min and reflux ratio was 5.The method of extractive distillation was secondly adopted to refine m-diethyl benzene and p-diethyl benzene.The solvent was preliminarily selected according to the simulation result of single state extractive distillation by Aspen Plus software.Experimental apparatus of single state vapor-liquid equilibrium was set up.The solvent was finally determined by measuring the vapor-liquid equilibrium data of components under different solvent systems and calculating the relative volatility of each component.Extractive distillation which used sulfolane as extractive solvent was simulated by Aspen Plus as well,and the conditions of simulation such as top product ratio,solvent ratio,reflux ratio,column plate number,material position and solvent position were studied.The experimental apparatus of extractive distillation was established on the basis of best simulation data.The results showed the purity of m-diethyl benzene mixture was 74.10%with the yield of 87.92%,under the conditions of that tower height was 220cm,material position was 110cm,solvent position was 30cm,material's feeding speed was lg/min,solvent's feeding speed was 3g/min,distillation flow rate was 0.7g/min and reflux ratio was 5.The experimental result corresponded with the simulation result.The triple continuous extractive distillation process of separating high purity m-diethyl benzene and p-diethyl benzene from C10 arenes was designed by Aspen Plus finally.The six conditions such as top product ratio,solvent ratio,reflux ratio,column plate number,material position and solvent position were discussed as well.According to the simulation result,the orthogonal experiment of six factors and five levels was designed to optimize the conditions.The simulation results showed that m-diethyl benzene was 95.38%with the yield of 91.02%after the second extractive distillation and that p-diethyl benzene was 95.54%with yield of 90.08%after the third extractive distillation.The method of combining continuous distillation and extractive distillation was adopted to refine the diethyl benzene fraction from C10 arenes,which can provide basic data for further research.