Thermolysis of petroleum oil and solubility of deposits

The article discusses the process of formation of deposits in the pipelines of the engine oil system and the factors affecting the conditions for their formation. The technological process of oxidation and the criteria for indicator parameters characterizing the thermolysis of used oil are shown. An extractive method is proposed that ensures the removal of deposits from the pipeline using special flushing process fluids based on regenerated petroleum oil. To search for cheap and efficient hydrocarbon raw materials, regenerated petroleum oils were chosen from among the renewable resources of oil refining. The proposed process fluid was prepared on the basis of low-viscosity spent and then purified petroleum oil. The viscosity of the petroleum oil was adjusted with the addition of petroleum kerosene or diesel. Diluted surfactant solutions were used as additives. and detergent additive (alkali metal salts). It was revealed that in the oil system of an automobile engine at high temperatures (200-350 0C) oil thermolysis occurs, and the resulting deposits contain asphaltenes, carbons and carboids. The efficiency of dissolution of deposits in the mixture under study at low temperatures and the concentration of surfactants were revealed. The dependence of the interfacial tension on the concentration of various surfactants is shown. The limiting amounts of the content of the constituent components are found and the ratio of oily extract, from deposits of oxidized oil, is selected. As a result of the tests, it was found that the washing liquid reduces the interfacial tension between the surface of the pipes and deposits and leads to an increase in the movement of the liquid. It has been established that the process of washing off deposits depends on the composition of the deposits, as well as on the composition of the oily extract. The optimal mode and prescription composition of the flushing liquid has been selected. The efficiency of washing off the studied liquid with other means is shown, while it should be noted that this liquid has a simple component composition and is much cheaper than other means.