Can vacuum distillation in industry completely separate oil from asphalt?
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Can vacuum distillation in industry completely separate oil from asphalt? Does the asphalt at the bottom of the vacuum distillation tower contain oil? Are there still n-hexane-soluble substances in the asphalt from the bottom of the vacuum distillation tower?
Can vacuum distillation in industry completely separate oil from asphalt? Asphalt can also be considered a type of heavy oil! The quality standards for vacuum-treated asphalt mainly depend on penetration, ductility, and softening point! If it contains oil, it might only contain waxed oil; but if the amount of waxed oil is high, how can the quality of the asphalt be ensured to be satisfactory?
Asphalt must contain oil; otherwise, its ductility will not meet the requirements.
It mainly processes raw materials similar to coal tar, with the main goal of recovering as much oil as possible. It would be ideal if there was no oil in the asphalt at the bottom of the vacuum distillation tower – is this achievable?
Firstly, the vacuum distillation towers used in industrial plants are unable to achieve precise separation of asphaltenes and non-asphaltenes, as coal tar has a very complex composition with a wide range of boiling points. Additionally, due to the limited height and number of trays in such vacuum distillation towers, their precision in separation is quite limited. To increase the oil yield, one can only raise the outlet temperature of the furnace, the vacuum level, the top temperature of the tower, and the amount of product taken off as side streams. However, doing so inevitably leads to an increase in the density of various products; the side stream products located lower down may contain asphaltenes, which can cause difficulties in subsequent processing steps. So it’s not the case that the more oil is extracted, the better; a comprehensive consideration is needed.
A set of solvent deasphalting equipment can be added; as far as I know, the asphalt market is saturated
Depressurization cannot achieve separation; an additional deasphalting unit is required for separation.