The atmospheric and vacuum distillation unit was originally designed to process crude oil with a high API value; now it needs to process crude oil with a lower API value. Will the processing volume decrease?
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Dear experts: I have a question. The atmospheric and vacuum distillation unit was originally designed to process crude oil with a high API value; now it needs to process crude oil with a lower API value. Will the processing volume decrease? (With the device remaining unchanged)
It definitely will. A low API density indicates a high content of heavy components. The draw rate in the atmospheric tower is low, while the load on the vacuum tower is high. The refinery where I work uses a \"slightly wet\" vacuum deep distillation technique in its vacuum tower to process low-API crude oil.
It is necessary to reduce the amount of processing； As the specific gravity increases, the heat transfer pressure drop rises, leading to overpressure in the feed line or overload of the feed pump. Reduced pressure leads to overload, an increase in wax oil, or difficulties in transporting residue oil. Adjustments are made based on the operation status of the equipment and the conditions of the raw materials
The amount of processing depends on the capacity of your vacuum and residue pumps; when processing heavy oil, it’s crucial to consider whether the residue can be removed
First and foremost, it is necessary to address the issue of the maximum processing capacity. Under normal circumstances, significant changes occur in the composition of the crude oil, which leads to substantial variations in the production volumes of light and heavy fraction products; the amount of heavy fractions increases greatly. This in turn causes changes in the heat exchange system, resulting in a decrease in temperature, which increases the load on the heating furnace. The increased production of heavy oil means that the flow rate of the heavy oil pump is no longer sufficient for production needs. Therefore, without altering the equipment, the maximum processing capacity has to be reduced. Moreover, since the columns remain unchanged, the opening rates of the tray openings as well as the locations of the side streams are not suitable for processing the new crude oil, which has a significant impact on both the yield and quality of the products.
It should have an impact; based on material balance calculations, the proportions of light and heavy oils vary, and it is necessary to determine whether the processing capacity of the subsequent treatment units is sufficient to handle the volume of material involved. If it can hold up, there’s no problem; otherwise, load reduction is definitely necessary