A model for a fluidised bed catalytic cracker

✍ Scribed by A.Z. Tigrel; D.L. Pyle

• Publisher: Elsevier Science
• Year: 1971
• Tongue: English
• Weight: 962 KB
• Volume: 26
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(71)86086-4

✦ Synopsis

model for the operation of a continuously operating fluidised catalytic cracker is developed on the basis of the two-phase theory of fluidisation. The model also incorporates the decay in catalyst activity which is a feature of cracking processes; the mean catalyst activity is evaluated using the residence time distribution for the particles.

The effect of variations in operating parameters on the reactor performance is illustrated, and it is shown that with either co-or counter-current flow of the catalyst particles there is an optimum circulation rate for conversion of the feedstock. The location of this optimum depends strongly on the extent of gas by-passing in the bubble phase, and in the case of counter-current vapour and particle flow there does not appear to be an optimum at all in the absence of bubbles.

It is suggested that the general method and the broad features of the results will apply to other fluidised bed reactors including catalyst circulation and decay.