In the first step of the study, the scientists synthesized the membrane material from polyacrylonitrile, the polymer used in the production of high-temperature resistant fibers. The researchers applied the polymer solution onto glass and immersed it into distilled water. Then they washed the resulting membrane with water and organic alcohols and dried it.
At the experimental stage, the scientists placed the membrane under high pressure and began to pass through it motor oil samples. Comparison made between the chemical composition of the “before” and “after” samples showed that the membrane had removed more than 95% of contaminants. The samples’ properties, including carbon composition, optical density, dynamic viscosity and acid number were close to the properties of the unused motor oil.
The new method for purifying motor oil does not require distillation or heating to high temperatures, so it is simpler than the other methods of separating liquids, including distillation.
“Membrane filtration will help reduce the need to produce motor oil from fossil oil, thereby saving energy and raw materials and supporting our country’s closed-loop economy. It is also worth noting that the polymer membranes we proposed can be reused. The experiments showed that the pollutants trapped by the material can be washed away afterward. In the future, we plan to study the process of concentrating useful components of the purified engine oil with the help of polymer membranes with finer pores,” the Russian Science Foundation quotes Vladimir Volkov, Doctor of Chemistry.
Membranes are porous polymer compounds retaining the outside substances; they are used not only for purification of petroleum products, but also for purification of thermal power plants emissions. Such membranes act as a filter having a balance between permeability to a certain gas and selectivity of its separation from the other gases in the mixture.
