Reaction Kinetics of Dehydrogenation of Diethanolamine
XU Guo-ming · Journal of Chemical Engineering of Chinese Universities · 2010
Diethanolamine dehydrogenation to form iminodiacetic acid is the key step for the glyphosate production.The reaction kinetics of diethanolamine dehydrogenation reaction over Raney-Cu catalyst was studied.The single-factor multilevel experiments were conducted to find out the effects of the initial concentration of diethanolamine,the amount of catalyst,reaction temperature and pressure on the dehydrogenation reaction.The kinetics data for diethanolamine dehydrogenation reaction were obtained by experiments carried out in a 5 L autoclave.Based on the mechanisms of diethanolamine dehydrogenation reaction,a kinetics model was proposed with the form of follows:-dCA/dt=VcatKAkCA/(1+KACA)·VL.The kinetics parameters in above model were numerically calculated by non-linear data fitting,and the results are:k=4.914×1010exp(-7.364×104/RT),mol·(L·cat)-1·h-1,KA=3.308×106exp(-5.450×104/RT),L·mol-1.The results show that the reaction rate controlling step is the dehydrogenation reaction on the catalyst surface,and the experimental results also show that the kinetics equation obtained is reliable in the range of the experiments.