Density fluctuations in catalytic unit regeneration inclined tubes
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My catalytic unit uses a catalyst cooler; the density of the material in the regeneration inclined tube, from the cooler to before it enters the lift pipe, varies from 1000 liters to around 1500 liters. This value returns to normal after some time. What could be the reason for this? Have you encountered such a situation?
The full name of catalytic cracking is fluidized catalytic cracking process, which involves the transportation of gas and solids. There is really a lot to say about the concept of fluidization; I would recommend that workers read President Lu Chunxi’s article on “Fluidization Technology in Catalytic Cracking” at https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=308229. Additionally, this design is said to be a patented project by a large engineering firm, and its main purposes are to reduce the temperature of the regenerated catalyst, increase the catalyst-to-oil ratio, and optimize the product distribution! But the actual results in use don’t seem very satisfactory!
The performance isn’t very good; we think it’s necessary to use it, unless it needs to be removed during maintenance
Anyway, as far as I know, it’s one company – the biggest one! The concept is good, but it’s not really suitable for catalytic units that have already been built; it disrupts the fluidization balance of the original system, and this issue wasn’t properly taken into account during the design phase! Upon inquiry, it turns out that many facilities simply treat this stage as a dead-end process, as if this step in the workflow doesn’t exist at all!
Is there any treatment for a bed that has become stagnant? Will a stagnant bed affect fluidization?
It was added on later; proper consideration wasn’t given during the design process, resulting in something that’s practically useless... Does it even have any purpose?……
The reasons are: 1. The loose points of the inclined tube were not adjusted properly; 2. The sulfurization air flow in the cooler was not set correctly; 3. There were fluctuations in the pressure of the non-purified air or the pressurized air; 4. Changes in the properties of the raw materials, as well as variations in the amount of coke formed, affected the coking process. Adjustments can be made in response to changes in density, gas production volume, and charring temperature.
It seems that there aren’t any significant fluctuations in the aspects you mentioned. Changes in the properties of the raw materials lead to changes in the burning effect, which in turn affects the carbon content on the catalyst and thus its fluidization properties
The particle size of the catalyst affects the fluidization effect; as the carbon content on the catalyst surface increases, the particle size also increases accordingly. An increase in the carbon content of the catalyst raises both the coking temperature and the flue gas temperature; the increased thermal driving efficiency of the flue gas also affects fluidization. These are just personal opinions.