芳烃型催化重整集总反应动力学模型

LUMPED KINETIC MODEL OF AROMATIC TYPE CATALYTIC NAPHTHA REFORMING

按集总理论指导原则,从催化重整反应机理出发,针对以生产芳烃为主要目的的重整装置,提出了1个包含27个集总、52个反应的催化重整反应动力学模型,并以移动床连续重整径向反应器为基础建立了相应的数学模型。该模型将C8芳烃进一步细分为乙苯和二甲苯2个集总,将C9芳烃进一步细分为三甲苯、甲乙苯和丙苯3个集总。采用工业实测数据估计了相应的111个模型参数。结果表明,所得动力学参数符合经典的双功能催化重整反应机理,由失活常数结果可见,酸中心失活比金属中心失活更为严重。通过UOP连续重整工业装置的模拟计算对模型进行了验证,结果表明,该模型能较准确地预测各反应物出口质量含量和催化剂出口积炭含量。该模型可为芳烃型重整装置的优化及产品组成预测提供重要依据。

According to the guiding principles of lumping theory, a new kinetic model involving 92 lumped components and 52 reactions for catalytic naphtha reforming was developed to satisfy the commercial reforming units to produce aromatics based on the reaction mechanisms, and a mathematic model is formed for continuous reforming moving-bed radial-flow reactor. The C8 aromatics were divided into ethylbenzene and xylene, and C9 aromatics were divided into trimethylbenzene, methylethylbenzene and propylbenzene respectively in the modeling. The 111 parameters were estimated based on the data from plant, which coincided well with the mechanisms of reforming reactions catalyzed by typical bifunctional catalyst. The deactivation constants showed that the deactivation on acidic sites of bifunctional catalyst was more serious than on its metal sites. The simulation of UOP commercial continuous reforming unit was carried out for verifying the model. The results showed that perfect agreement of material compositions and catalyst coke content at the exit of the fourth reactor was obtained between simulated values and actual values, which means that the model could predict aromatic composition in detail and provide a basis for optimization of reforming unit to produce aromatics.