The Research On The Separation Of Butanone-Ethyl Acetate By Extractive Distillation

Butanone and ethyl acetate are two common organic solvents.After mixing the two,they form the lowest azeotrope,which cannot be separated by ordinary distillation.Therefore,this paper uses ethylene glycol as an extractant to separate butanone and ethyl acetate.First,the infinite dilution method was used to select ethylene glycol as the extractant,and ethylene glycol was used as the extractant to conduct the intermittent extractive distillation experiment.The experimental results prove that the separation requirement can be achieved,the change curve of ethyl acetate at the top with time is obtained,and high-purity ethyl acetate is obtained.Using the batch module of Aspen Plus,the simulation of batch extractive distillation was carried out,and the simulation effect was in good agreement with the experimental results.For the continuous extractive distillation process,the sensitivity analysis function of Aspen Plus was used to study the effects of extractant feed rate,reflux ratio,feed position,and number of trays on product purity.The best operating parameters were found when the raw material feed is 1000kg/h,the best operating parameters are:ethylene glycol feed amount is 500kg/h,extractive distillation tower tray number is30,mass reflux ratio is 0.45,raw material feeding position is the 17 th tower,The feed position of the extractant is the fifth tray,the number of the solvent recovery tray is10,the mass reflux ratio is 0.5,and the feed position is the fourth tray.Under the best operating parameters,ethyl acetate with a mass fraction of 99.91% and methyl ethyl ketone with a mass fraction of 99.60% were obtained,and the mass fraction of ethylene glycol reached 99.99%.The ethylene glycol to be replenished is only0.179 kg / h..Finally,the Aspen Plus Dynamics module is used to import the steady-state file under the best process conditions into the dynamic simulation.The control structure with fixed reflux ratio,fixed R / F control structure and fixed QR / F control structure are analyzed and studied first.With different dynamic control schemes,it was found that the purity of the product could not be maintained after the disturbance of the added feed amount and feed composition.Add a composition controller to check the reason and find that the ethyl acetate purity cannot be maintained because the solvent ratio is small.Finally,increase the solvent ratio and use the improved fixed reflux ratio control structure.After encountering the disturbance of the feed volume and feed composition,the response can quickly reach a steady state,ethyl acetate with a purity of greater than 99.5% and methyl ethyl ketone with a purity of greater than 97% can be obtained separately.The robust control is realized,which provides certain guiding significance for industrial production.