加氢裂化宏观动力学模型研究

A STUDY ON MACRO-KINETIC MODEL OF HYDROCRACKING PROCESS

所建立的加氢裂化宏观动力学模型，考虑了原料油的组成、操作参数以及催化剂等主要因素的影响，模型直观，简捷明了而不失真，且避免了复杂费时的数学计算。应用模型可预测各种条件下的产品分布及氢耗，模拟效果良好。

In this paper,the kinetics model is founded by considering the hydrocracking reaction sys-tem(products and feedstocks)as composed of two cuts(shown as cut￣+ and cut￣-,respectively). The heavier fraction(cut￣+) cracks via a first-order reaction to form the lighterfraction (cut￣-).The reaction equation is written as The kinetics differential equation is the hydrocracking products are divided into gas,light naphtha (LNA ),heavy naphtha(HNA),jet fuel(JET),diesel(DIE)and unconverted oil (UNCO).Based on equation(2),their vields are expressed as The velocity constants are functions of the hydrogen partial pressure,hydrogen-oil ratioand reaction ternperautre. To a given catalyst, the activated energy is only governed by theproperties of the feedstock.The experiments were carried out on the fixed bed of the hydro-cracking pilot. The operation mode is the single-stage series once through(SSOT).Threegroups of catalyst were used which have been widely applied in industry. The operation condi-tions were selected as : reaction temperation, 340～390℃,liquid hourly space velocity(LHSV),1.0～2.6h￣(-1),hydrogen partial pressure(pH2),8.0～14.0 MPa,hydrogen-oil ra-tio (HOR),600～1400 V/V, Although the kinetics rnodel is simple,but it can be used topredicate efficiently the product yields,to evaluate the relative activation of the catalysts andoptimize the products structure,The results predicted fit the experirnental data fairlv well.The model can also supply basic datum for engineering design and for industrial production. Inthe meantime , the mathematical difficulty of polyparameter estirnation in studying the kineticsof complex reaction system is avoided.