Fractionation tower re-refining tank
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What are the reasons for coking in the re-refining tank of the catalytic unit’s fractionation system?
If the re-refining tank cokes, will the bottom of the distillation tower also coke?
The raw materials play a role, temperature matters as well, and your operations also have an impact.
First, it is necessary to check whether the amount of slurry returning to the surface is sufficient to ensure effective washing of oil and gas; for other aspects, reference can be made to measures taken at the bottom of the tower to prevent coking
If the re-refining tank cokes, the bottom of the distillation tower is more likely to coke as well. There are many reasons for this. First, it relates to the raw materials. The crude oil becomes heavier, increasing the liquid phase load. Secondly, improper operation resulted in the bottom temperature remaining above the specified process limits for an extended period.
What does that mean? Could you explain it in detail?
The distillation temperature of the reprocessed oil is definitely not low
If the amount of slurry returning upward is low, the oil and gas washing effect cannot be ensured; as a result, the catalyst is carried to the upper trays and then enters the re-refining system, causing coking. Secondly, the reprocessed oil has a high temperature, slow flow rate, and long residence time, which may exacerbate coking. I agree with others’ views: if the reprocessed oil system suffers from coking, the slurry system should be even more affected