Abstract:

Based on the flow pattern of perfect mixing and the age probability density exponential function of equilibrium catalyst in commercial FCC unit, a model equation was established by derivation of catalyst deactivation kinetics, in which equilibrium catalyst activity or micro-reactor activity was related to carbon and metal contents on catalyst, replacement rate of catalyst, temperature and steam partial pressure in regenerator. The mathematical model with high calculation precision for equilibrium catalysts activity or micro-reactor activity was developed through the simulation for operation data of commercial FCC unit and model parameter estimation. The comparison of model parameters indicated that the effect of V contaminate on catalyst activity is the biggest and the effect of Na is the smallest, while the effect of Ni and Fe is in the middle. The results predicted by the model showed that the activity or micro-reactor activity of equilibrium catalyst increases with the decrease of metal and carbon contents on catalyst and the increase of catalyst consumption. It would be advantageous to the activity or micro-reactor activity of equilibrium catalyst to reduce properly the catalyst hold-up or the temperature in regenerator.

Key words: catalytic cracking, catalyst, deactivation, kinetics, equilibrium catalyst activity, metal contamination, mathematical modeling

摘要：

基于催化剂全混流流动状态和呈指数形式的催化剂年龄概率密度函数,经催化剂失活动力学方程推导,确定了关联催化剂碳含量、金属沉积量、催化剂置换率、再生器温度和水蒸气分压的平衡催化剂活性或微反活性模型方程。对工业催化裂化装置操作数据进行模拟计算,确定了催化剂失活模型参数,建立了具有较高模拟计算精度的裂化催化剂失活动力学和平衡催化剂活性模型。比较模型参数大小可知,V沉积对催化剂活性的影响最大,其次是Ni和Fe,Na的影响最小。模型预测结果表明,随着平衡催化剂金属沉积量或碳含量减少,催化剂单耗增大,平衡催化剂活性或微反活性逐渐增大。适当降低再生器温度和催化剂藏量有利于提高平衡催化剂活性。

关键词: 催化裂化, 催化剂, 失活, 动力学, 平衡催化剂活性, 金属污染, 数学模拟