3 replies to this topic

[ssskharche]

why gasoil is used directly as a diesel fuel ?

why it doesn't require the proceesing like gasoline?

 

 

thank you

[Napo]

Ssskharche,

You need to review the local regulations, specially for the sulphur content. You need a crude oil with very very low content in sulphur for employ directly gas oil as diesel. You need a finish treatment for comply the regulation.

In the gasoline case we need others process for increase the octane number, obviously with anothers treatments.

Napo.

[colt16]

Because Diesel fuel and Gasoline fuel is different. Quality of Gasoline is determined by octane number which is a function of aromatics and naphthenes content in gasoline. Hence Naphtha which has paraffins (low octane number) needs to be catalytically reformed to have aromatics that have high octane number. Before it can be catalytically reformed, it needs to be hydrotreated to remove things that can poison the catalytic reformer catalysts. Thus these are already two additional processing steps. The other gasoline blendstocks from alkylation unit and so on are a different path into the gasoline pool.

Quality of diesel on the other hand is based on Cetane Number. The more straight chain paraffins you have the higher the cetane number. Generally Diesel cut from Crude Tower will already meet Cetane specifications without issues. What is left is some desulphurization to be perfomed depending on where you are and what is the sulfur spec required.

[rdcrags]

This is usually an issue of not being familiar with stream names. Gas oil (note space) is the cut heavier than diesel and lighter than residue. It is typically fed to FCC or hydrocracking units. Gasoil (no space) is what diesel fuel is called in some regions. Same as U.S. diesel except for diesel index spec. Gasoil does have a wider boiling range in some regions than does U.S. diesel fuel, however, and that leads to the confusion.