Catalysis Of Ethyl Lactate Synthesis And Pervaporation Dehydration Of Ethanol

As basic organic chemical raw materials, ethyl lactate have been widely used in the industry fields. Ethyl lactate is a kind of excellent green solvents, and could be an excellent alternative of the solvents which is harmful to environment. Traditionally, the production of ethyl lactate is carried out with lactic acid and alcohol as starting materials, in the presence of concentrated sulfuric acid. But this process usually will lead to the formation of by-products and equipment erosion. Therefore it has attracted great attentions to investigate new catalysts which can replace concentrated sulfuric acid.For the esterification reaction, strong acid cation exchange resin has advantages of high selectivity, high catalytic efficiency and high repetition rate. In this work, ethyl lactate were synthesized with the catalysis of regenerated perfluoro-ion-exchange membranes which as strong acid cation exchange resin. Influence factors on the preparation of ethyl lactate were explored. Lactic acid conversion was obtained in67.5%in the presence of regenerated perfluoro-ion-exchange membranes at75℃for240min, with1:4of lactic acid/alcohol as the starting materials.The reaction kinetics for the liquid phase synthesis of ethyl lactate over regenerated perfluoro-ion-exchange membranes catalyst was investigated in three flask. According to the kinetic date, the kinetic equation was regressed by the model of pseudo homogeneous phase. Without consideration of internal and external diffusion, the concentration change of lactic acid with reaction time was determined and the parameters of the kinetic model were evaluated by the initial reaction rate method. The frequency factor was7.98×105L·(mol·min)-1and activated energy was53.17kJ·mol-1. the dynamics equation can be expressed as follows:-rHL=x0.76472×7.98×105e-53.17×105/RT(CHLCEIOH-CELCW/1.45)(mol·L-1·min-1)Achievements in this work will be helpful for preparation of ethyl lactate in industry with strong acid cation exchange resin as catalysts.At last, the pervaporation performance of the PVA membrane were studied using the flat-plate membrane module made in our laboratory with a diameter of100mm(effective area:0.001256m2). The pervaporation performance of PVA/PES membrane, PVA—CS/PES membrane and PVA—CS—CNT/PES membrane in ethanol/water was tested. The experimental results show that the pervaporation performance of PVA—CS—CNT/PES membrane is best, separation factor is75, permeation flux is268g·m-2·h-1...