The regeneration technology of waste lubricating oil is widely used in machinery, chemical industry and other fields. The used engine oil is often discarded because it is mixed with water, organic matter, pigment, dust and other impurities. According to the principle that oil and water are immiscible and the boiling point of water is lower than that of engine oil, water can be removed by heating and static separation. Organic matter is removed by concentrated H2SO4 oxidation, pigment is adsorbed by activated clay, and mechanical impurities are removed by filtration, thus achieving the purpose of engine oil regeneration.

Steps/methods

dehydrate

Waste engine oil is collected in the oil collecting tank to remove water, and then placed in the oil refining tank. After the temperature rises to a certain temperature, stop heating, let it stand for about 24 hours, so that the surface water can be discharged, and then slowly raise the temperature to a certain temperature (when the oil temperature is close to 2 dollars, it should be heated slowly to prevent the oil from boiling and overflowing), so as to evaporate the water. After about two hours, the oil did not turn over and black oil and gas emerged from the oil surface.

Suitable for pickling

After the oil is cooled to normal temperature, slowly add sulfuric acid (concentration is about 92 ~ 98%) under stirring, and the amount of acid added generally depends on the degree of oil pollution. After adding the acid, continue to stir for half an hour, then let it stand for about 12 hours, and discharge the acid residue.

alkaline wash

Reheat the oil after pickling, add soda ash (Na2CO3) while stirring, fully stir and let it stand for 1 hour, and let it stand for more than 4 hours after the test paper is neutral, and then discharge the alkali residue.

Activated clay adsorption

Heat the oil to a certain temperature and keep it at a constant temperature, add activated clay (its dosage is about 3.5-5% of the oil) while stirring at a constant temperature, continue stirring for half an hour after adding activated clay, stand at a specific constant temperature for one night, and filter while it is hot the next day.

filter

It can be filtered by oil filter, and qualified oil can be obtained after filtering. If there is no oil filter, you can also use the method of hanging and filtering with cloth bags.

end

Matters needing attention

The above is the general operation flow of oil purification, but it depends on the actual situation. If there is little water containing impurities, the first step can be omitted; If the color of oil is normal after acid and alkali treatment, it is not necessary to decolorize and adsorb with activated clay.