Is diesel at normal pressure better or hydrotreated diesel better?
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I’d like to hear everyone’s opinions on whether normal-pressure diesel is better or hydrotreated diesel. Personally, I think normal-pressure diesel is better; I’m curious to know what others think.
Well, it depends on how you compare them. If the catalysis is geared towards diesel production, then its cetane number is likely to be better than that of conventional processes. But these days there’s a tendency to produce more gasoline, so the quality of diesel seems to be given less importance; therefore, it might not be as good as that produced by conventional methods, but it’s not certain either, hehe
This depends on the subsequent refining process, as well as the type of crude oil being processed. For example, the paraffin-based crude oil from Daqing produces diesel fuel at atmospheric pressure (that is, straight-run diesel) of good quality, with low gel content and a high cetane number. Catalyzed diesel, especially that produced using heavy catalysis, has a cetane number of less than 45 and high levels of gum; samples taken from the pipelines quickly turn a color similar to that of soy sauce, and hydrogenation refining is necessary to meet the quality standards. However, these two types of oils are generally not sold separately; they are offered for sale only after being blended into finished products.
Generally, vacuum distillation is preferred, but its yield is low, and it tends to be used for producing gasoline, resulting in limited comparability. Both types of oil need to be blended before being sold.
Of course, normal pressure is better! The crude oil supplied to refineries is becoming increasingly of lower quality! Catalyzed diesel isn’t much better either! The diesel cetane number of our equipment is generally only around 28! Hydrogenation is necessary~
At atmospheric pressure, it is straight-run diesel. Generally, based on the pattern of cetane numbers of various hydrocarbon fractions in diesel, straight-run diesel has the highest cetane number. Catalyzed diesel has a lower cetane number due to its higher content of polycyclic aromatic hydrocarbons. Of course, it is also affected by the properties of the raw materials. The diesel cetane number of paraffin-based crude oils is higher than that of naphthenic-based diesel.
At atmospheric pressure, it is straight-run diesel. Generally, based on the pattern of cetane numbers of various hydrocarbon fractions in diesel, straight-run diesel has the highest cetane number. Catalyzed diesel has a lower cetane number due to its higher content of polycyclic aromatic hydrocarbons. Of course, it is also affected by the properties of the raw materials. The diesel cetane number of paraffin-based crude oils is higher than that of naphthenic-based diesel.
Of course, straight-run diesel is the better choice; anyone who has studied petroleum processing knows this. Before the implementation of the Euro III standard, catalyzed gasoline was of high quality; now, catalytic converters are facing issues related to the quality of gasoline and diesel, requiring further processing.
At normal pressure, diesel is of good quality; there’s no need to consider the cetane number. Visually, straight-run diesel has a better color than catalyzed diesel, which in turn has a better color than coker diesel. Of course, in the end all of them are blended together, so it doesn’t make any sense to talk about which one is better or worse.
Catalyzed diesel has high sulfur and nitrogen contents as well as a high olefin content. During processing, a large amount of hydrogen is consumed, causing the temperature to rise
It is generally believed that vacuum distillation yields better quality diesel, while both atmospheric and catalytic processes produce diesel that requires blending before use. Photocatalytic diesel engines have difficulty starting, and their cetane number is lower than that of conventional diesel.
Needless to say, diesel at normal pressure is better; visually, the color of straight-run diesel is better than that of catalytically processed diesel, and its quality is more stable. It can leave the factory without hydrogenation. The quality of Cuichai diesel is unstable; it contains a high amount of olefins, and hydrogenation is required. Although both are ultimately blended, straight wood chips are pure pulp, while accelerated wood chips are a mixture.
Stop arguing. Hydrogenated diesel is better; it’s difficult to get diesel out of production without hydrogenation. What do you think, those who work with hydrogenation? ! :lol