Why does the dilute-phase temperature increase with catalytic freshener addition? (Oxygen-poor regeneration)

1. The bed level is too low. 2. The wind pressure used for transporting the catalyst feed is too high, resulting in a reduced amount of air used

I still don’t quite understand; I’m a beginner. Under normal operation, the dilute-phase temperature is usually around 700 degrees; today, after adding fresh agents, it rose to 750 degrees. If it were a problem with the air flow, the temperature wouldn’t rise so quickly.

The bed level is too low; the pressure of the conveying air is high and the flow rate is large, resulting in instability of the bed layer and abnormal charring.

Could it be that the addition rate was too fast, resulting in overheating at the rear? Also, is the interval between additions too short or is the duration of each addition too long? We usually control the addition to occur every half hour, for about 100 seconds each time

So I asked why there is overheating and what the principle behind it is

This post was last edited by lilei8610 on 2012-10-10 22:32. The temperature of the freshener is at room temperature, while the temperature of the catalyst in the regenerator is as high as 700°C. When a freshening agent is added, the large temperature difference between the freshening agent and the regenerating agent causes a sharp drop in the local temperature of the bed layer, resulting in a poorer coking effect. In some areas, the coke does not burn completely, leading to an excess of oxygen. Excess oxygen passes through the regenerator bed into the dilute phase, where it reacts with CO to release heat. Due to the low catalyst content in the dilute phase and the lack of heat-carrying catalysts, the temperature in this zone rises sharply, resulting in overheating in the dilute phase. Therefore, when adding fresh agents, close attention must be paid to the temperature in the dilute phase zone to prevent secondary combustion.

Okay, thank you. I finally understand.

What was said on the 7th floor is already quite comprehensive; one additional point is that the high activity of the fresh catalyst leads to reduced selectivity and increased coking, which disrupts the balance between burning and coking – and this is also one of the reasons for the rise in temperature. As for the temperature drop earlier, I fully agree with what was said on floor 7

In addition to what has been mentioned above, 1) the 0-40um content of freshening agents is generally around 17, while that of balancing agents is around 15; a high content of fine powder is also one of the factors. 2) When low-temperature catalysts enter the regenerator, some of the catalyst particles may experience thermal expansion, which is also a contributing factor.

I’ve learned something; I make a little progress every day! ! Thank you, masters! ! !