Relationship between FCC catalyst activity and yield
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I would like to ask everyone: what is the relationship between the activity of FCC catalysts and the yield of light oil? If the activity increases by one unit, how much does the light oil yield change? Thank you!
There should be a range; generally, the microreactivity of catalysts is around 65. The level of light yield is determined by many factors, not just catalyst activity; therefore, knowing only the level of activity is not enough to determine the amount of light yield.
There is indeed an issue of optimizing catalyst activity, with main considerations including the properties of the raw materials, the properties of the system balance agents, and the desired yield of the target product. The catalyst activity in typical units ranges between 60 and 72; if it is too high, while the gasoline yield may increase, the gas yield and coking rate also rise. The optimal catalyst activity for each specific device will vary.
Activity is usually expressed as conversion rate. It has high activity and a high conversion rate as well. However, conversion rate and yield, especially the liquid yield, are not the same concept. The conversion rate is too high, which may lead to a rapid increase in coke and gas yields; the liquid yield reaches a peak and then starts to decline after that point. Therefore, it is not possible to specifically describe how light harvesting changes when activity increases by one unit.