Research And Development Of Catalyst For Dimethyl Oxalate Dydrogenation Ethylene Glycol

Ethylene glycol is a kind of important chemical raw materials.The traditional production technology dependent on non-renewable resources of oil, it generated by ethylene of Petroleum refinery oxidation to ethylene oxide and ethylene oxide hydrate generation ethylene glycol. And green technology was developed, it generated by synthesis gas catalytic accidentally united into dimethyl oxalate and dimethyl oxalate hydrogenate for ethylene glycol. A route for the subsequent hydrogenation process is the difficulty of green technology. Early exploitation catalyst of DMO hydrogenation catalyst contain chromium, it can pollute environment. In recent years, copper base catalyst was used for DMO hydrogenation reaction in this process, it showed good activity, but it had a short service life, so it is necessary to develop a catalyst that it is a highly active, long cycle, and environmental friendly catalyst.Through the investigation of catalyst carrier, active component of load, steamed ammonia temperature, calcination temperature and reduction temperature, it was found that the best preparation should be using silica sol as the carrier.when content of Cu is25%in this catalyst, the steamed ammonia temperature is90℃, catalyst calcination temperature is450℃and reduction temperature is350℃, it can get high DMO conversion and EG selectivity. The optimal DMO conversion is99.95%and EG selectivity is95.65%. Additionally, based on the investigation to this catalyst, the optimal reaction conditions were studied.The optimal reaction temperature is200-215℃, press is1.5-3.0MPa, space velocity is0.75-1.0h-1, the ratio of H2and DMO is70-90.In order to improve the reaction performance and service life of the catalyst, the promoter B, La, zinc was added. Through the preparation of samples for analysis and evaluation, it concluded that promoter B can improve the performance of the catalyst, promoter La would be helpful to improve the catalyst life, although it make the DMO conversion rate dropped, Adding promoter of zinc can improve the catalyst activity, but it makes EG selectivity decreased obviously.Several characterization methods, such as XRD, TPR, TG, SEM, were applied to discuss the effects of the catalyst promote. It showed that the catalyst showed good response performance when the catalyst active component copper exist Cu0, Cu+two forms.When thereaction run after300hours, we found that the deactivation Cu0grain has obviously increasesand the carbon content is higher in deactivation sample.Combined with the SEM analysis, itconcluded that the main cause of catalyst deactivation is carbon deposition of catalysts andcopper sintering of the catalyst active component.