How to Properly Dispose of Used Engine Oil

Motor oil, the lubricant of the engine, can play the role of lubrication, cleaning, cooling, sealing, wear reduction, rust prevention, and corrosion prevention for the engine. After a long period of use, motor oil will produce deposits, sludge and varnish, which will lead to deterioration. These substances are deposited on the surface of friction parts, lube orifices and filters, which can also cause various machine failures.

Then in order to avoid these problems, it is necessary to change the oil diligently to ensure a sound operation of the equipment. Used engine oil is the used lubricating oil replaced from all kinds of construction machinery, vehicles and ships.

With the rapid development of industry, the demand for motor oil is also increasing, and every year, in order to get rid of used engine oil, it is dumped or incinerated regardless of the consequences. This is not only a problem of environmental pollution, but also an energy crisis, so how should we properly dispose of used engine oil?

Where Does Used Engine Oil Go?


Used oil that has been replaced is often not valued because of its low economic value and is dumped into rivers, field clearings or garbage bins. This practice can cause significant environmental pollution and waste of resources. Studies have shown that one barrel (200L in volume) of used oil poured into water can pollute 3.5 square kilometers of water. Moreover, the heavy metal salt additives and organic substances such as anti-wear agents containing chlorine, sulfur and phosphorus contained in lubricating oil are harmful to people and organisms, and these substances mixed into water may eventually end up endangering human health through various channels.


At present, using used engine oil as fuel is also a common treatment method. Many construction sites will mix used motor oil with other construction waste that needs to be incinerated and then incinerate to destroy it, and this disposal method is also very harmful to the environment.


The used engine oil will be transported to the refinery for recycling, and the used engine oil of bad quality will be turned into fuel oil through dehydration, distillation, cooling, bleaching and other "renovation" means, and then blended with the regular national standard oil according to a certain ratio to form poor quality diesel oil. The better quality used engine oil will be processed to remove the deteriorated components and impurities and pollutants to become recycled lubricants, and then flow to the engine oil market through packaging. But this method requires precise control and strict requirements.

Road oiling

Spraying used engine oil on dust-prone roads and using its adhesive effect to hold the dust in place and provide dust control is also a treatment method for used lubricants. In the United States, a significant portion of recycled used lubricating oil is used for this purpose. However, used oil sprayed on roads can also be washed into drains by rainwater when it rains, eventually entering rivers and polluting water or entering soil and contaminating it, so it can also pollute the environment.

How to Properly Dispose of Used Engine Oil?

The recycling of the replaced used lubricating oil is undoubtedly the most appropriate way, which not only can make full use of the resources, but also can bring considerable economic benefits, and also avoid the environmental pollution caused by random discarding.

Decanter centrifuge is one of the best solution for oil purification and waste oil regeneration.

Working principle:

Due to the difference of density between oil and water, the oil-water mixture will generate different centrifugal force under high speed rotation, thus separating oil and water. The material enters the centrifuge through the central feeding tube, and under the action of centrifugal force, the solids will settle on the wall of the bowl, while the liquid phases with different densities will form concentric cylinders, with the lighter liquid phase in the inner layer and the heavier liquid phase in the outer layer. The thickness of the different liquid rings can be changed by adjusting the overflow weir and the variable impeller. The solids deposited on the wall of the bowl will be conveyed by the screw to the cone end and discharged through the discharge port.


Uses of Refined Used Engine Oil

Although the use of diesel oil refined from used engine oil for vehicles may damage the fuel system of vehicles, it is not a big problem for the use of stoves used by catering companies or some mechanical plants. The price of the fuel refined from used engine oil is much cheaper than the gas in the market, and many catering companies and machine shops are willing to use this fuel.

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