Fluidization problem
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Dear teacher: In catalytic cracking, why does a catalyst with a high specific gravity degas more quickly and is harder to fluidize?
Because it has a high density, so its weight is heavy
The greater the specific gravity of the catalyst, the faster it separates from the fluidizing medium, meaning degassing occurs more quickly, which makes fluidization difficult.
When the catalyst has a high specific gravity, as can be seen from its particle size distribution, there is less fine powder in the 0–40um range; this increases the porosity between the catalyst particles, which is beneficial for degassing. Additionally, in the catalyst formula, the amount of molecular sieve decreases while the proportion of carriers such as kaolin increases. The larger pore sizes of these carriers also contribute to degassing. This is my personal understanding; please correct me if I’m wrong!