催化裂化结焦催化剂烧焦再生模型的研究(I)*——烧焦再生物理模型的建立

摘要

Models of FCC coked catalyst particles and coke burning dynamics were analyzed.It was pointed out that to study the coke burning reaction of coked catalyst must take the view point of macrodynamics.Not only intrinsic dynamics of coke burning must be considered,but the diffusion transfer resistance of gas phase in the process of coked catalyst burning considered as well.Coking burning process of greater particle catalyst can be simulated by the particle-pellet model,homogeneous model and shrinking unreacted core model.These models have much greater errors to pellet zeolite catalyst.Considering the characteristics of zeolite catalyst,a modified pellet-particle model was put forward and its physical structure,coke distribution and coke burning steps discussed in detail,supplying a basis for establishment and deduction of mathematical equation of the model.%对催化裂化结焦催化剂颗粒模型和结炭燃烧动力学进行了系统的分析和研究，指出研究结焦催化剂的烧焦反应过程必须采用宏观动力学的观点，既要考虑结炭燃烧的本征动力学，又要考虑结焦催化剂烧焦过程中气相组分的扩散传递阻力；并指出大多数催化剂颗粒模型如粒子-颗粒模型、均匀模型、未反应核收缩模型等对大颗粒催化剂的烧焦再生过程能够较好地进行模拟，但对粒径微小的沸石催化剂烧焦再生的模拟误差很大。根据沸石催化剂的特点，提出了修正的颗粒-粒子动态等温物理模型，并对该模型的物理结构、焦炭分布以及焦炭燃烧的步骤进行了详细的描述，同时也为该模型的数学方程的建立和推导提供了依据。