How to handle tail combustion in the regenerator
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My unit uses a partial regeneration method, with single-container fluidized coking. The current problem is that the temperature in the regenerator’s dilute phase is around 680 degrees, but it can reach 730 degrees at the inlet of the cyclone separator; once the material enters the three-cyclone system, the temperature drops back to around 670 degrees. Why is this? How can this be resolved? Should CO be added as an auxiliary fuel?
Increase pressure, increase main air flow, increase storage capacity, increase coking temperature; adjust the distribution of main air, adjust the steam used for stripping, adjust the oil-to-air ratio, adjust the ratio of recycled materials, adjust the amount of material processed in the reaction and the degree of reaction; identify suitable additives.
Add the third floor, calculate the hydrogen-to-carbon ratio, increase the reserves in the stripping section, and improve the stripping efficiency. There might be unexpected gains.
An inlet temperature of 730°C in the cyclone separator definitely indicates secondary combustion; the temperature drops again as it enters the third cyclone. If there is no issue with the temperature sensors, it’s possible that the CO has been completely burned off by then, or that the excess oxygen is only sufficient to sustain combustion up to that point. However, this situation not only damages the catalyst but also causes damage to the equipment itself. Regardless of the regeneration method, it is necessary to adjust the main air volume appropriately to control the oxygen content and ensure a certain level of coking effect. During operation, changes such as the processing volume, oxygen content, properties of the raw materials, stripping efficiency, storage capacity, and weather conditions can all affect coking (except in cases where the main air distribution pipes are damaged). It is necessary to keep the temperature of the dense phase in the regenerator within an appropriate range, and pay attention to changes in the temperature difference between the dense and thin phases (10°C–25°C). If this temperature difference starts to increase gradually, add an oxidizing agent or reduce the amount of main air supplied, while monitoring the temperature changes in various areas. If the temperature difference decreases, ensure that the temperatures in all areas drop simultaneously to prevent carbon buildup; in such cases, it may be possible to increase the amount of main air, but care must be taken to avoid secondary combustion. For the situation you mentioned, I tend to think it is caused by an excessive temperature difference; this can be controlled by reducing the main air flow at the beginning or by adding combustion aids. The above analysis and suggestions are purely personal opinions
Adjust the inventory level and it’s solved