Catalytic cracking units are present in most refineries to convert a large
fraction of heavy oils. Over the last 50 years, catalyst development and im
provement of the technology in the reaction zone lead to a continuous evolu
tion, that is still going on, of this process. In this paper, R&D tools for
technology are discussed through the development of riser separation syste
ms and catalyst coolers. Catalyst circulation aspects in the reaction zone
are also discussed.