Research On The Synthesis Of Ethylene Glycol By Methanol And Formaldehyde

This research deeply discussed and optimized the technical conditions in the synthesis of ethylene glycol(EG) by methanol and formaldehyde. By a lot of experiments, di-tertiary-butyl peroxide(DTBP) and dicumyl peroxide(DCP) were chosen as the evocator in the method of synthesis by one-step or multi-steps. The affections of the amount and flowrate of evocator, reaction temperature and time, mass ratio of methanol to formaldehyde, catalyzer were also discussed. Finally, the way of synthesis was optimized and simplified, the yield was increased.This research also includes new method on the synthesis of DTBP. Then the goal of recycle, decreasing cost and clear technology are basically realized. The product was analysed by red infrared spectrum and gas spectrum. Improved process that changed the mol ratio to 0.64 and feeding method could make the yield reach to 92.5%, as well as the purity to 99.6% . It also could increase the reaction temperature to 15℃The optimum one-step synthesis conditions are as follow, using DTBP as evocator, reaction temperature and time were set to 145℃and 4h,the mass ratio of methanol/formaldehyde was 8, the content of DTBP in raw material was 2.5%, the dropping speed of DTBP was 0.5ml/min.When the reaction terminated, the mass content of EG in the product could reach to 9.65%, one mol DTBP can produce 7.6mol EG.. DCP was able to make the yield be about 12% by several steps of reaction.Furthermore the separation process was simulated and optimized. Through the reaction distillation process, EG could be got at the bottom of reaction distillation tower with the purity above 90%.