Abstract: This paper begins by tracing the origins of catalytic cracking processes, briefly reviewing their evolution from the initial fixed-bed operations, through a short phase of moving-bed processes, to the development of fluidized bed technologies, and ultimately to the circulation fluidized bed processes. Subsequently, the focus is on the rise of research in fast fluidized beds, particularly the systematic research efforts in this field by domestic scientists represented by Mooson Kwauk. During the development of theoretical models, the Institute of Process Engineering, Chinese Academy of Sciences, worked closely with SINOPEC and other entities to jointly promote several significant upgrades of catalytic cracking process technologies, including the technology for fast fluidized bed regenerators and the technology for maximizing the production of isomerized alkanes in diameter-transformed fluidized bed reactors. With the continuous advancement of catalytic cracking technology in China, domestic research on fast fluidized beds is also deepening, with the scope of research expanding from experimental observations to axial models, multi-scale theories, and multi-scale simulation methods. By reviewing the development trajectory of fast fluidized bed research and its close relationship with catalytic cracking processes, this paper aims to provide insights and ideas for the study of new technologies and theories, in the hope of promoting the future development and application of fluidization technologies.

Key words: fluidization, fast bed, catalytic cracking, multiscale, simulation