Heavy oil is a product of separation of secondary refining products, boiling at 350-360ºС, from the oil. This is a viscous dark brown substance.
Pyrolysis treatment of heavy oil consists of two stages. At the first stage, the substance is heated, separating the liquid part. The output is the pyrolysis oil, which is a long distillate, similar to heavy fuel oil in its properties. Selling this product is more lucrative than selling heavy oil.
The second treatment stage is the distillation of the pyrolysis oil. This results in gasoline and diesel fractions, as well as residual oil, which can used in further recycling.
It should be noted that the pyrolysis process is still under development. There are reasons to believe in development of the existing and implementation of new processing technologies. There are two main directions of research: catalytic pyrolysis and pyrolysis with the addition of various substances, which facilitate decomposition of the hydrocarbon substances and slow side reactions.