重质油裂解-气化双功能催化剂制备与反应机理研究

Efficient utilization of heavy oil (represented by extra-heavy oil, oil sand/bitumen and vacuum residue) by cracking-gasification process has received extensive attention because of the degradation and extinction of conventional petroleum, giving the strategic direction for heavy oil processing. A bi-functional catalyst with both effects of oil cracking and coke gasification was studied, thus to enhance the liquid yield in cracking and meanwhile to realize catalyst regeneration by coke gasification and produce syngas. Catalysts with specified pore structures and moderate activity were prepared by hydrothermal synthesis, atomization molding and impregnation modification methods, and then characterized the cracking acidity, gasification alkaline sites and the mutual effects. Heavy oil cracking was conducted in a self-made fluidized bed reactor to investigate the product distribution and study the heavy oil molecules cracking mechanism over the catalysts with different pore structures and acidic sites. The effects of pores and catalytic sites on coke reactivity for the catalysts are carried out in a micro-fluidized bed reactor to build up the kinetic model of catalyst regeneration via coke gasification. Finally, based on the characterization and experiment results, the reaction mechanism of oil cracking and coke gasification is revealed over the catalysts with different pore structures and acidic-alkaline sites and thus to provide some fundamentals for the catalyst development and heavy oil carking gasification process.

随着原油重质化与资源减少，通过裂解-气化技术实现以稠油、油砂沥青与炼厂减压渣油为代表的重质油的梯级高效利用得到了广泛关注，代表重质油加工的战略方向。本课题将研究同时具备催化重质油裂解与其形成焦炭气化活性的双功能催化剂，不仅提高重油裂解液体收率和品质，而且催化重油裂解生成焦碳的气化以副产合成气并同时再生催化剂。通过水热合成、喷雾成型和浸渍改性等方法制备特定孔结构与催化活性的催化剂，研究制备方法对催化剂孔结构与酸-碱活性位的作用规律；采用流化床反应装置考察重油裂解产物分布，研究不同类型催化剂的孔结构与酸性中心对重油大分子的作用机理；利用微型流化床反应分析仪研究焦炭活性与催化剂孔结构以及催化气化中心的对应关系，建立积碳催化剂气化再生动力学模型；基于表征与反应评价优化催化剂制备过程，揭示催化剂孔结构与酸-碱活性位对重油裂解与焦炭气化的作用机理，为重质油裂解气化技术与催化剂开发提供理论基础。