A new process for the synthesis of dimethyl maleate:III esterification of methanol and maleic anhydride catalized by Mg-β and Fe-β zeolites

This work studied using Mg-β and Fe-β zeolites as the catalyst of the esterificatin of methanol and maleic anhydride.First,the calcination temperature was investigated and found best at 550℃ for Mg-β catalyst and best at 350℃ for Fe-β catalyst.Then,the effects of reaction temperature,reaction time,amount of the catalysts on the yield of dimethyl maleate were also investigated.Experimental results indicate that there exists an optimum reaction temperature and catalyst amount.For the Mg-β catalyst,the amount is 0.5 percent of the maleic anhydride,and it lows to 0.3% for the Fe-β zeolites.Both catalysts behave best at 110℃,the yield of dimethyl maleate reach 93.74%(Mg-β catalyst) and 91.91%(Fe-β catalyst) after 12 hours reaction.