催化裂化再生器中平衡催化剂年龄分布及水热失活模拟

Mathematical simulations of age distribution and hydrothermal deactivation for equilibrium catalyst in regenerator of catalytic cracking unit

基于催化剂全混流流动状态,确定了呈指数形式的再生器中平衡催化剂年龄概率密度函数,建立了关联催化剂置换率的催化剂平均年龄数学期望关系式。依据催化剂水热失活动力学模型方程确定了再生器中平衡催化剂催化活性数学模型。通过3套工业装置操作数据模拟,计算各装置因数。模型预测结果表明,催化剂置换率越高,再生器中催化剂平均年龄及年龄分散程度越小,平衡催化剂微反活性越高。在催化剂单耗不变时,随着再生器催化剂藏量减小或原料处理量增大,平衡催化剂微反活性均持续变大。适当减小再生器催化剂藏量,以及降低再生温度和水蒸气分压均有利于提高平衡催化剂微反活性。

Based on the flow properties of complete stirred-tank regenerator, the age probability density exponential function of equilibrium catalyst in regenerator of commercial FCC unit and mathematical expectation equation of catalyst average age related to catalyst replacement rate were determined. Based on catalyst hydrothermal deactivation equation, the mathematical model of catalytic activity for equilibrium catalysts in regenerator was developed. The unit factors of three FCC units were calculated through the micro-reaction activity simulation with the mathematical model. The model prediction results showed that the average age and age distribution extent become all to small, the micro-reaction activity of equilibrium catalyst increases along with catalyst replacement rate. If the regenerator＇s temperature or steam fraction pressure is lower, the micro-reaction activity of equilibrium catalyst in regenerator is higher. If catalyst consumption is invariant~ the micro-reaction activity of equilibrium catalyst increases along with the catalyst content of regenerator becoming to small or stock processing amount of commercial FCC unit becoming to large. It would be advantageous to the micro-reaction activity of equilibrium catalyst to reduce properly the catalyst content or the temperature or steam fraction pressure of regenerator.