Study On Transesterification Of Isopropyl Formate With Methanol

Isopropyl formate is a by-product of a certain process,and uses in combustion as fuel because its little value in industrial applications.Therefore,this paper explored a consumption way of isopropyl formate by the transesterification with methanol to produce methyl formate and isopropanol which have more industrial values.The catalysis of different alkali and acid catalytic systems were observed,and the kinetic behaviours of the transesterification reactions isopropyl formate with methanol were studied and kinetic models were established accordingly,and its parameters were obtained from the experimental results by regression.The results are as follows:The transesterification experiments were carried out in a high pressure reactor of 100 mL.Firstly,different alkali catalysts such as KOH,NaOH,717 strong basic anion exchange resin and sodium methoxide were selected to catalyze the transesterification reaction of isopropyl formate with methanol.The catalytic effect of catalysts on the reaction was studied under different conditions,and the suitable catalyst sodium methoxide was selected for further investigation.Using sodium methoxide as catalyst,the effects of reaction conditions(reaction temperature,molar ratio of raw materials and catalyst dosage)were investigated.The optimized reaction conditions are obtained as follows:reaction temperature is 433.15 K,methanol/isopropyl formate molar ratio is 5:1,catalyst sodium methoxide dosage is 0.5%wt of the total raw materials.The highest equilibrium conversion of isopropyl formate is 67.8%.The kinetic equation of transesterification reaction of isopropyl formate with methanol was derived based on the homogeneous second-order reversible reaction model.The kinetic parameters(positive activation energy is 126.64 kJ·mol-1,reverse activation energy is 148.38 kJ·mol-1,reaction enthalpy is-21.74 kJ·mol-1)were obtained by regression from the experimental results under 413.15-453.15 K.The experimental results at different methanol/isopropyl formate ratios show that the kinetic model has good reliability.Different acid catalysts such as acid 292-1 resin,3 A molecular sieve and solid acid HND-580 were also selected to catalyze the transesterification reaction of isopropyl formate with methanol.The catalytic effect of catalysts on the reaction was studied under different conditions,and the suitable catalyst acid 292-1 resin was selected for further investigation.Using acid 292-1 resin as catalyst,the effects of reaction conditions(reaction temperature,molar ratio of raw materials,catalyst dosage)and reusability of catalyst were investigated after eliminating the influence of external diffusion over resin particles.The optimized reaction conditions are obtained as follows:reaction temperature is 433.15 K,stirring rate is 300 rpm,methanol/isopropyl formate molar ratio is 5:1,catalyst acid 292-1 resin dosage is 0.5%wt of the total raw materials.The highest equilibrium conversion of isopropyl formate is 86.2%.It is also found that the catalyst has good reusability.The kinetic equation of transesterification reaction of isopropyl formate with methanol was derived based on the homogeneous second-order reversible reaction model.The kinetic parameters(positive activation energy is 34.83 kJ·mol-1,reverse activation energy is 53.28 kJ·mol-1,reaction enthalpy is-18.46 kJ·mol-1)were obtained by regression from the experimental results under 413.15?453.15 K.The good kinetic model reliability was verified.Because the transesterification of isopropyl formate with methanol catalyzed by acid 292-1 resin is a liquid-solid phase reaction process,LHHW and ER adsorption models were built to describe the transesterification reaction of isopropyl formate with methanol under the assumption of monolayer adsorption.The corresponding parameters were obtained through experimental data processing by Matlab software.And the activation energy of the surface reaction over resin is 122.33 kJ·mol-1.The obtained LHHW and ER model equation were used to predict the transesterification reaction under 433.15 K and different methanol/isopropyl formate molar ratios,and the results were compared with the experimental data.It can can be found that LHHW model has good prediction and is more suitable to describe the transesterification process of isopropyl formate with methanol.