Study On Lactate Esters Dehydration To Acrylic Acid And Its Esters By New Catalyst

This article is about the research of dehydration reaction of lactateesters to produce acrylic acid and its esters. Catalysts are prepared byblending MMT and zeolite that synthesized by a simple hydro-thermalreaction. Through kinds of continuous catalytic reactions, we researchedthe influences to dehydrant products of lactate esters caused by thedifference of temperature and agent, such as the kind of product and itsyield rate；the activity of catalysts blending with different ratio of MMT;the necessity of organic base and its effect to dehydration reaction; thesuccession of catalyst activity and its regeneration. The research alsostudied the dehydration mechanism of lactate esters in weak baseambiance.The research reveals that, in the existence of weak base, the rising oftemperature is conducive to the dehydration of lactate esters in certainscale, higher temperature will give a negative effect. The optimaltemperature of dehydration to methyl lactate is320℃, and to ethyl lactateis290℃.Under the optimal temperature, lactate esters in alcohol agent willgive acrylate esters as majority in catalytic reaction, and acrylic acid thatin water. The dehydration of lactate esters will have a better result inalcohol agent than that of taking in water. The conversion rates of lactateesters in all reactions reach70%. The conversion rate of ethyl lactate even comes to100%when taking methanol as agent, and it also has the highestyield rate of dehydration,71.91%.Among catalysts that have different ratio of MMT blending withzeolite,20%Li type MMT catalyst has the best activity to the catalyticreaction. Compare with the zeolite bought from market, zeolite thathomemade has a better effect.With the comparison of catalytic reaction of lactate esters that withand without organic base, the research finds that the adding of base wasnecessary to keep the stability of catalyst activity, but more base willcause negative effect.The catalyst that newly produced has very high activity, but it willfall down in a few hours. The time is about3to4hours. The activity ofcatalyst will be activated when temperature rises to500℃and keeps2hours. The falling of activity of catalyst is caused by the blocking of somepore path.The mechanism of catalytic reaction was studied by the difference ofdehydration that caused by agent, it's E2reaction mechanism.