Which delayed coking units conduct regular analysis of the four components of residue? Is there any practical value in this?
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Which delayed coking units conduct regular analysis of the four components of residue? Is there any practical value in this?
In catalysis or heavy oil catalysis, it is generally useful to conduct regular analyses of the four components, as this is helpful for operation. But now, faced with a complex and critically scarce raw material market, do you still have to use all types of oils? As for the raw materials used in coking, there’s no need to overuse them; it’s better to use them in moderation, as that is beneficial for the furnace tubes. Working with four components is still quite time-consuming
Four-component analysis is definitely useful, mainly regarding the contents of resins and asphaltenes; the mechanisms of coking proposed by experts such as Professor Xiao from the Petroleum University are all based on asphaltenes；
This analysis certainly needs to be conducted on a regular basis as a reference. The trend of crude oil becoming heavier is becoming increasingly severe; if you fail to adjust the circulation ratio or the temperature at the outlet of the heating furnace in a timely manner based on changes in these four components, the plant will eventually stop functioning. The salt content in crude oil is also worth paying attention to, and the same goes for the situation after desalination!
Four components need to be analyzed; the raw materials from the refinery itself are relatively stable, so the frequency of analysis can be reduced appropriately. The situation with local refineries is special, as the raw materials are quite varied. It is recommended to conduct regular analyses; as mentioned above, make corresponding adjustments to the process based on the properties of the raw materials.
It is very necessary; when the properties of the raw materials change, the operating conditions must also change. Daqing residue and Gudao residue show significantly different coking tendencies, and their operating conditions differ greatly. Raw materials with a high pitch content result in rapid coking, and the furnace tubes are prone to coking. If the pitch content is particularly high (e.g., above 8%), pellet coke is likely to form, so the temperature at the furnace outlet should be reduced. Raw materials with a high gel content, although they produce a large amount of coke, are easy to handle.
Our company does not carry out delayed coking, but it’s still beneficial to take the time to do it, as it can be helpful for the operations
As for analyzing the four components in the coking unit, I don’t think it’s necessary to do so; of course, doing it is better than not doing it, but it’s just too time-consuming. Our unit conducts such analyses once or twice a year, and due to the frequent changes in raw materials, it doesn’t provide any practical guidance. General precautions: 1. For raw material analysis, only sulfur content, residual carbon, and density are tested. 2. Measure the empty height of the coke tower. 3. Coke hardness during coking removal. That’s fine!
I believe that conducting four-component analysis holds some value in terms of guiding production, especially as it is very helpful for the long-term operation of coking processes. However, its usefulness is reduced when raw materials are changed frequently, because performing a four-component analysis on residue takes a considerable amount of time; by the time the results are available, the raw materials may have already been changed.
For companies whose coking feedstock properties change frequently, conducting a four-component analysis can provide guidance for production; it would be even better if model simulations could be used for analysis.