Please explain the difference between catalyzed diesel and coker diesel ? And explain the reason

The feedstock for delayed coking is generally residue, and the chemical reaction that produces diesel is a thermal cracking reaction that follows the mechanism of free radical reactions. The feedstock for catalytic cracking is generally wax oil or paraffin-based atmospheric residue, and the chemical reactions that take place are primarily catalytic cracking reactions under the action of acid catalysts, following the normal carbon ion mechanism; simultaneously, aromatization reactions and hydrogen transfer reactions also occur. Coked diesel has a high sulfur content and a high level of unsaturated hydrocarbons; its cetane number is higher than that of catalyzed diesel, but it is unstable and prone to discoloration. Its density is lower than that of catalyzed diesel, its aromatic content is lower as well, and it contains more impurities. Catalytic diesel has a high degree of unsaturation, a high density, and many impurities as well. Catalyzed diesel has better stability than coker diesel, but it has a high aromatic content and a low cetane number. After hydrorefining, both types of diesel show significant improvements in color and stability. However, generally speaking, the cetane number of the catalyzed diesel after hydrogenation is lower than that of the cokerized diesel after hydrogenation. This post was last edited by hgshy on 2009-4-12 19:52]

Catalyzed diesel has a high density and contains many naphthenes and aromatics. Hydrogenation requires a large amount of hydrogen, results in a low cetane number, and even modification is needed to meet the requirements. Coker diesel contains a high amount of unsaturated hydrocarbons and tends to discolor easily.

The density of accelerant wood is higher, the bromine value of charred wood is higher; when hydrogenating accelerant wood, the temperature rise is lower

I would like to ask about the differences between diesel produced by heavy oil catalysis and delayed coking.

Catalyzed diesel has a high content of aromatics, while coked diesel has a high content of olefins.

Can it be understood in this way that the quality of coke diesel after hydrogenation is better than that of catalytic diesel after hydrogenation, with the quality criteria being that hydroprocessed coker diesel is superior to hydroprocessed catalytic diesel?

Coker diesel has a higher cetane number than catalytic diesel, but due to its high content of unsaturated hydrocarbons, it is highly unstable and must be refined before it can be released for sale； Catalytically stabilized diesel has a low cetane number, and it can only be released for sale after hydrogenation. As for the raw materials, they are all similar – heavy oil.

I’ve learned that it seems these two types of diesel have lower quality compared to the diesel produced by atmospheric and vacuum distillation units

This post was last edited by Refiner on 2009-6-26 10:53. The sulfur content of coke wood is higher than that of accelerator wood； The nitrogen content of charred wood is lower than that of accelerated-aging wood ； The density of charred wood is higher than that of accelerated-aging wood, and its final melting point is also higher ； The cetane number of charred wood is higher than that of accelerated wood ；

The lower nitrogen content in charred wood compared to accelerated-aging wood is likely due to differences in the raw materials and the reaction processes involved! ! !

“The density of accelerant wood is higher, the bromine value of charred wood is higher, and a smaller temperature rise occurs when accelerant wood is hydrogenated. What does it mean by a higher bromine value on the fourth floor?

“The density of accelerant wood is higher, the bromine value of charred wood is higher, and a smaller temperature rise occurs when accelerant wood is hydrogenated. What does it mean by a higher bromine value on the fourth floor?

Catalyzed diesel has a high density and contains many naphthenes and aromatics. Coker diesel contains a high amount of unsaturated hydrocarbons and tends to discolor easily.