Thermal balance of catalytic cracking

It’s that the burning load of your regenerator is too high

It is likely that the increase in catalyst residence time leads to an increase in coking, which in turn results in more heat being generated and a rise in temperature.

As the reserve increases, the residence time of the catalyst in the regenerator increases, leading to thorough coking and a larger amount of coke formation; this results in an increase in the heat released, and consequently the bed temperature in the regenerator rises. The answer on the 3rd floor is correct.

Firstly, there are many reasons for an increase in the bed temperature; when the reserve level is high, it’s possible that a certain factor changes, leading to an increase in the bed temperature, which makes one think that there is a causal relationship between them. Secondly, if there are no reasons for poor burning and the amount of burning remains constant, then as the reserve increases, the bed temperature should decrease. Just as one kilogram of firewood can heat one kilogram of water, what would happen if the firewood remains unchanged but the weight of the water increases? Third, the scenarios mentioned by the two posters in positions 3 and 4 cannot be ruled out either. In short, when it comes to carrying out tasks, it’s necessary to think about problems, but one must avoid putting oneself in a dead end; one needs to be flexible. Problems that are truly difficult to understand should be set aside for now, as there are indeed some issues that are very hard to explain clearly.

I still agree with the third floor option: it has a large capacity and allows for a longer stay, which enables more thorough burning. But at the same time, consider the impact of air volume as well; a slight increase in storage capacity may not have a significant effect on bed temperature. At the same time, consider the form of the regenerator as well! !

The inventory in the regenerator determines the residence time of the catalyst within it; increasing this inventory can prolong the burnout time, thereby increasing the amount of coking. This is just one of the reasons for the increase in regeneration temperature. 1 Oxygen partial pressure 2 Carbon content in catalyst

This post was last edited by xutj01 on 2009-6-2 08:55. The question raised by the original poster is highly valuable for research! Suggestion for improvement! I. Ideal state: The reserve level varies, while the temperature of the regeneration bed remains constant. II. Actual state: When the reserve value is high, the temperature of the regeneration bed is higher. Why? 1. It’s not a perfect burn in an ideal state; increasing the amount stored can prolong the burning time, thereby increasing the amount that burns. Floors 4, 7, etc.: good! This problem is a heat equilibrium problem. 2. It is not a perfect mixing in an ideal state; in reality, the temperature of the dilute phase in the regenerator – the temperature of the dense phase ≠ 0 ； It is estimated that there is a certain temperature difference; high storage levels can exacerbate catalyst backmixing and prolong heat transfer. This problem is combustion dynamics. 3. OP, you could provide more detailed information about the situation (regenerator structure, dimensions, temperatures of the dense and dilute streams in actual production, etc.). This will be useful for everyone’s discussion! 4. In combustion, the flame temperature varies, which is related to the flame height and size ； Secondly, the catalyst does not start burning as soon as it enters the regenerator; there is a process of temperature increase and ignition, etc., which is also related to factors such as air volume and space velocity.