Study On The Synthesis Of Methyl Glycolate By Reactive Distillation

Use the reactive distillation equipment designed by laboratory, methanol acid A solution which contains salt was reactant, cation exchange resin was catalyst. Conversion and yield were improved by taking water and ester out of the tower. The process condition of space velocity, reaction temperature, reactant ratio, reflux ratio was studied by the orthogonal experiment and the optimal process condition was determined by single-factor experiment. The results showed that mole ratio of methanol and acid A, space velocity had greater impact than reflux ratio and kettle temperature. On the condition of mole ratio 8, space velocity 0.013min-1, kettle temperature 85-95℃, catalyst loading 200g/L, the conversion of acid was 98.62%, yield of ester was 96.05%.Process conditions were optimization by Aspen Plus chemical simulation software. NRTL equation was selected as thermodynamic model and the binary phase diagram of acid-water-methanol-ester was calculated by Aspen Plus. The optimization simulation conditions are:the theoretical stages is 15, the number of reactors are 5, mole ratio of methanol and acid is 5, and the relative mistakes of simulation results are about 5%. Through the Aspen Plus simulation results, the theoretical basis of reactive distillation process was obtained to optimize the process, and pointed out the direction of the industrial scale.Esterification product was distillated and hydrolyzed by cation exchange resin. Reactive temperature, catalyst weight and ratio of water to ester were studied in the hydrolysis process. Water and methanol were removed from the hydrolysis and acid was got. Hydrolysis conversion of ester is over 95% at the condition:mole ratio of water to ester is 5, catalyst weight is 5%, top temperature is over 66.5℃.