Abstract:

Fluid catalytic cracking (FCC) is a crucial conversion process in a petroleum refinery, which produces important chemicals, e.g. gasoline, diesel, light olefins, etc. Computational fluid dynamics (CFD) modeling of FCC reaction processes assists to understand the behaviors of flow and reaction in FCC riser reactors, design and optimize the FCC units, and finally provide the guidance for production and implement the virtual tuning and scale up of processes. This study reviews the recent processes in the multiphase flow models, reaction kinetics and the coupling between flow and FCC reaction. In terms of the coupling approaches, summaries and critical comments are present from the usage of turbulent models, the impact of flow structures, more sophisticated models to crude oil vaporization models. Based on the previous studies, it is pointed out by the authors that although CFD modeling can well reveal the behaviors of flow and reaction in FCC riser reactor of industrial scale, the current theoretical models and modeling techniques have a long way to run up with the experiment counterpart since there is no successful application of CFD reactive modeling of a series of FCC riser reactors ranging from a bench scale to the industrial scale. For the future of FCC reactive modeling, it is very necessary to emphasize the studies on the modeling and the computing efficiency, then strike a balance between them to realize the virtual process engineering.

Key words: FCC, multiphase flow, reaction kinetics, two-fluid model, simulation

摘要：

流化催化裂化（fluid catalytic cracking，FCC）工艺是石油炼制中的重要转化工艺，用于生产汽油、柴油、轻质烯烃等重要化工原料。FCC反应过程的CFD模拟有助于理解FCC反应器中流动和反应行为，辅助设计和优化FCC工艺设备，最终指导工业生产和实现虚拟调控和放大。从与FCC反应模拟相关的多相流动模型、反应动力学模型以及流动与反应之间耦合等方面做了回顾和总结。在流动与反应耦合研究方面，从湍流模型的使用、流动结构的影响、精细化模型的发展以及原油汽化模型的重要性这4个角度做了分析比较及总结。基于已有的研究工作，认为虽然很多研究表明CFD模拟能较好地揭示工业FCC提升管反应器内的流动和反应行为，但缺乏采用同一方法实现从小试到工业反应器模拟放大的实例，从侧面反映了当前的FCC理论模型和模拟技术还远未达到可以代替实验的水平。展望未来的FCC反应模拟，建议从模型精细度和计算效率上加强研发，并在此两方面寻求平衡，最终实现虚拟调控。

关键词: 催化裂化, 多相流, 反应动力学, 双流体模型, 模拟