The ratio of the coke yield to the residual carbon value in coking units is often greater than 2; what could be the reason?
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This post was last edited by Refiner on 2009-8-16 20:16. The ratio of the coke yield to the residual carbon value in our plant is often greater than 2; we’re not sure what’s causing this issue. I would appreciate it if experts could help me analyze how to reduce this ratio. Thank you
The furnace temperature is too low or the quality of the raw materials is too poor.
I think it is due to an increase in the circulation ratio aimed at raising light yield; our circulation ratio is around 40-50
I concluded that it is mainly influenced by operational parameters such as the cycle ratio, operational stability, and system pressure.
Please provide your parameters. Sinopec requires that the residual carbon value/petcoke yield be less than 0.7; in other words, the ratio of coke yield to residual carbon value should be around 1.4.
Raw material density: 922, residue carbon: 8, coke yield: 17. The furnace outlet temperature is 500 degrees, the carbon tower inlet temperature is 492 degrees, the top of the tower is at 420 degrees, the tower pressure is 0.2 MPa, and the recycle ratio is 0.4
The residual carbon analysis data is incorrect. It should be above 10.
Our residue carbon content has always been between 7 and 9; we’ve never seen it exceed 10
Mainly, the residue is too light, and in addition, the circulation rate is high, which results in a large amount of wax oil participating in the reaction and increases the coke yield. The withdrawal rate of the atmospheric and vacuum distillation unit seems to be relatively low. The relative density of residue/heavy oil is generally >0.934, API
For coking feedstocks, a density of 0.922 is too low.
9# canoliu: The circulation ratio of our unit is 0.6 as per the design value, while it is 0.4 in actual production; it shouldn’t be considered high, right?