重油加氢处理与催化裂化过程中的分子管理工程基础

Fluid catalytic cracking is a major method for converting heavy oil into light products. In China, the processing capacity of FCC units has over 200 million tons per year. As the requirement of clean products and productive processes, the hydroprocessing of FCC feedstocks become the first choice. However, as the lack of understanding of the two reaction processes at the molecular level, the saturated aromatics become polycyclic aromatics again by dehydrogenation reactions in the FCC process, which increases the yield of slurry and reduces the efficiency of molecular management. This project will have a deeper understanding of heavy oil at the molecular level by the molecular distillation and advanced analytic methods. The molecular simulation will help to understand the hydrogenation of polycyclic aromatics and the catalytic cracking of naphthenic aromatics at the molecular level. Furthermore, the influencing mechanism of molecular structure size, catalyst properties, and reaction conditions on the saturation of polycyclic aromatics and the cracking of naphthenic aromatics will be studied. On the basis of the experimental results, the novel FCC catalyst will be developed, which can enhance the ring-opening reaction of naphthenic aromatics, realize the relay of ring-saturating and ring-opening reactions of polycyclic aromatics at the molecular level, and lay the foundation for the development of novel technologies for converting polycyclic aromatics into high value-added products. Finally, molecular kinetic models of heavy oil hydroprocessing and catalytic cracking will be modified and the system model will be established to realize the process simulation and control at the molecular level, which can increase the yield and value-added of products significantly.

作为重油轻质化的重要手段，我国催化裂化（FCC）年加工能力已超2亿吨。随着产品质量升级和生产过程清洁化要求不断提高，对FCC原料进行加氢预处理成为首要选择。但由于对两个反应过程分子水平转化规律认识不深入，导致加氢饱和的环烷芳烃在FCC过程中重新脱氢生成稠环芳烃，增大FCC外甩油浆量，降低分子管理效率。本项目将采用分子蒸馏和先进分析手段从分子层面深入认识重油资源；结合分子模拟技术深入研究多环芳烃催化加氢和环烷芳烃催化裂化分子水平转化规律，认识烃分子结构尺寸、催化剂性质和反应条件对多环芳烃加氢饱和及环烷芳烃开环裂化的影响机制；开发FCC专用催化剂，促进环烷芳烃开环裂化反应，实现多环芳烃加氢饱和与开环裂化反应在分子尺度上的接力，为发展多环芳烃定向转化新技术奠定基础；进一步完善重油催化加氢和催化裂化分子尺度动力学模型，并建立系统模型，实现整个过程的分子级模拟及优化控制，大幅提高目的产品收率和附加值

石油是宝贵的不可再生资源，提高原子经济性是炼化技术开发的核心问题。本研究以富芳重油催化加氢与催化裂化过程中的分子管理增效，系统优化富芳重油催化加氢和催化裂化反应过程，实现目的产品收率和附加值最大化为总体科学目标。首先，采用分子蒸馏、核磁、全二维气相色谱-质谱联用仪、傅里叶变换离子回旋共振质谱等先进技术从分子层面上深入认识富芳重油及加氢重油在组成和结构上的差异，获得芳烃化合物的组成与结构信息；其次通过模型化合物的加氢和催化裂化实验，结合分子模拟技术深入认识分子三维尺寸、催化剂性质、反应条件等对多环芳烃催化加氢和环烷芳烃催化裂化反应过程的影响规律，确定了多环芳烃适度加氢和环烷芳烃定向转化的适宜条件，提出了多环芳烃在加氢过程的吸附机理与扩散规律和环烷芳烃催化裂化反应机理；再次，以富芳重油催化加氢和加氢重油催化裂化中试实验为基础，结合上述研究结果研究了加氢过程的动力学模型，构建了加氢重油催化裂化反应的分子尺度动力学模型，深化石油资源分子水平转化规律认识，并在此基础上开发了加氢重油催化裂化专用催化剂；最后，提出了富芳重油加氢-催化裂化耦合工艺并进行了中试试验，结合ASPEN HYSYS建立系统模型并进行优化分析，实现了多环芳烃加氢饱和与开环裂化过程在分子尺度上的接力。通过本项目的研究，在富芳重油的分子表征与分子组学、多环芳烃加氢饱和的反应机理与条件优化控制、环烷芳烃催化裂化反应机理与定向转化调控机制、富芳组分加氢饱和—催化裂化耦合反应动力学与系统优化等方面取得了重要的结果，对富芳重油分子级转化、实现低价值原料高原子经济性加工、将多环芳烃定向转化为BTX等有机化工原料等过程的深入认识具有重要的科学意义。为我国炼油产业从“燃油型”向“化工型”转变过程中，石蜡基、中间基和环烷基原油加工路线的选取，提供了理论指导。