氨合成催化剂还原动力学

A Study of the Reduction Kinetics of Ammonia Synthesis Catalyst

在热天平上使用等温还原法考察了 A110-2型氨合成催化剂的还原动力学、还原气中氢分压的改变对还原速率的影响和 A110-2型催化剂粒度变化对其还原性能的影响;用“收缩核模型”提出了 A110-2型倦化剂的还原动力学方程。试验表明,在0.034—2.07mm 粒度范围内,A110-2型催化剂粒度大小的改变,不影响其反应控制机理,但明显影响反应速率指前因子值的大小。从气相反应物在固相反应物上吸附强弱和反应级数之间的关系,阐述了氢分压对还原速率的影响随着还原的进行而发生变化的内在原因。

The reduction characteristics of ammonia synthesis catalyst A110-2 were investigated with a thermal balance.A reduction kinetic equation for catalyst A110-2 was established and tested to indicate that this reaction mechanism con- formed to the shrinking-core model.In addition,the effect of pellet size of samples and the H_2 content in reduction gas on reduction kinetics were studied.The expe- rimental resultsshowed that pellet size had no effect on reaction mechanism for A110-2 catalyst,but pellet size of 0.034-2.07mm,would obviously impair the value of preexponential factor.The effect of H_2 partial pressure on the rate of reduction was found to be dependent on x,the reduction degrees of the cata- lyst.