The Study Of Ethyl Propionate Produced By The Technology Of Reactive Distillation

Ethyl propionate are important organic synthetic and solvent,and have wide application in chemical,pharmaceutical,food and other fields.The traditional ethyl propionate production process is intermittent or semi-continuous,and the esterification reaction was carried out in reaction kettle or fixed bed with concentrated sulfuric acid as catalyst.After that,the product is obtained through neutralization,water washing and distillation.This kind of method has a large investment in equipment and it is also difficult to follow-up product purification.The reactive distillation can achieve continuous production,high conversion of raw materials and high product purity.Therefore,reactive distillation technology was chosen to synthesize ethyl propionate in this topic.In this paper,the kinetics of ethyl propionate was studied in batch stirred tank reactor after selecting the strong acid cation exchange resin Amberlyst45 as the best catalyst.The effects of stirring speed,catalyst amount,mole ratio of Propionic Acid:Ethanol and reaction temperature on the reaction process were investigated.A quasi-homogeneous reaction model was established and the kinetic data was fitted using the least squares method to obtain the kinetic equation of the reaction.The kinetic equation is used as the basic data to input the chemical engineering software,and the process of reactive distillation to synthesize ethyl propionate is simulated and optimized.The optimized results are as follows: the number of rectifying section,reaction section and stripping section of the rectifying column are 8,20,and 3.Propionic acid and ethanol were fed from the top and bottom of the reaction section respectively,respectively.The mole ratio of propionic acid:ethanol was 1.3:1,the ester phase in the top of towter was partially refluxed,and the reflux ratio of the ester phase was 1.8.A stainless steel catalytic distillation tower was set up for esterification of ethyl propionate.The reaction section was loaded with a catalyst pack,and the rectifying section and stripping section were filled with ?3×3 mm stainless steel ? mesh packing.Under the optimal conditions of simulation,the influence of the feedind position,The mole ratio of propionic acid:ethanol and the reflux ratio of the ester phase on product purity were studied.It was finally determined that there were 24 plates in the total tower,propionic acid was fedfrom the 7th plate and ethanol was fed from the 21 st plate,the mole ratio of propionic acid:ethanol was 1.3:1,and the reflux ratio of the ester phase was 1.8.Under this condition,the conversion rate of ethanol was 93.13%,and the content of ethyl propionate was 89.97%in the top tower.After the separation of water and ethanol by the phase separator,the content of ethyl propionate can reach 95.88 %,and the propionic acid content was in accordance with the industry standard for the product.The experimental results are in good agreement with the simulation results,and the model selection is accurate and reliable.