Can naphtha produced in larger quantities by hydrocracking units be used as a feedstock for straight-run diesel?
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I would like to ask my fellow Sichuanese friends: what will happen if straight-run diesel feedstock is used in a hydrocracking unit? The current processing plan for the hydrocracking unit aims to produce more naphtha. Since diesel is difficult to sell, it is being considered whether straight-run diesel can be fed into the hydrocracking unit; large amounts of residue oil and diesel are to be recycled to produce more naphtha, which will serve as feedstock for reforming. It is not clear whether this approach is feasible, and I hope professionals can provide guidance.
It’s feasible; wherever there are refineries in the country, such operating units exist!
The catalyst must have high selectivity; otherwise, the gas yield will be too high, affecting efficiency!
It is possible to feed the material into the unit, but doing so with straight-run diesel will increase the diesel yield; as for the production of heavy naphtha, it depends on the catalyst as well as on the degree of reaction. Generally, when the dry point of the diesel is kept between 330–340°C, the boiling range of the heavy naphtha remains within the range of 75°C–160°C℃
Are there any approximate yield figures for a full cycle of diesel and residue oil processing, with only naphtha and gas as outputs?
It is definitely possible; there is only one set of diesel hydrocracking units in the country, and unfortunately it has not yet been put into operation, but it was designed by a patent holder. It should be noted that if the original design was for a paraffin oil cracking unit, temperature must be carefully controlled after switching to diesel to prevent overheating. Furthermore, to avoid a significant decrease in liquid yield, the space velocity should be increased and the reaction temperature appropriately reduced.
May I ask where the diesel hydrocracking unit you are referring to is located?
Yes, our second-stage cracking reactor can now process diesel produced by this facility or diesel from the diesel hydrogenation unit. As for the specifics, it also depends on the properties of your raw materials, as well as proper control of the reaction temperature