Abstract: The feasible executions of FCC processes based on the technical idea of "low temperature contact and high catalyst/oil ratio operation" were analyzed systematically. These processes could be categorized into two groups according to the material and/or energy exchange modes between system and surrounding. Various case studies following this idea were discussed and some positive results showed that the heavy oil crackability was enhanced, product slates were improved and clean fuels were produced cleanly.

Key words: catalytic cracking, low temperature contact, high catalyst/oil ratio, systematic analysis, technical effect