Study On Catalytic Dehydrogenation Of Diethanolamine For Iminodiacetic Acid

This thesis includes the Mn stability of CuMnOx catalyst,the preparation methods and preparation conditions of CuFeOx catalyst, and the process conditions of the catalytic dehydrogenation of diethanolamine.The different precipitation methods on preparing CuMnOx were compared, It is confirmed that the sequential precipitation method is better and when the CuMnOx catalyst pretreated by alkali will show more stability.The optimum preparation conditions of CuFeOx catalyst are that, molar ratio Cu/Fe of 1, the concentration of mix solution of 0.4mol/L,the pH of solution of 10, the temperature of precipitation of 70℃, the temperature of calcinations of 550℃, and the temperature of hydrogen reduction of 210℃,under the optimum process conditions for the catalytic dehydrogenation of diethanolamine:the reaction temperature of 150℃,the reaction pressure of 0.7Mpa, the reaction time of 3 hours, iminodiacetic acid(IDA) salt yield of 91.1% was obtained. During catalyst stabilization evaluation,it showed that over 80% of IDA yield,when Cu:Fe:Mn=l:0.4:0.6,the IDA yield can be upto 94.8%.Under the continuous Fix-bed process conditions for the catalytic dehydrogenation of diethanolamine:m(NaOH):m(DEA)=0.88, weight hourly weight velocity2.0hr-1, the reaction temperature of 170℃,the reaction pressure of 0.8Mpa,IDA yield of 22.1% was obtained,and it showed that the Fix-bed reactor and process can use for continuous catalytic dehydrogenating of diethanolamine.