Purification of motor oil is quite an important process with the annual growth of the number of vehicles. More automobiles mean more motor oil to dispose of, or to purify by restoring its qualities for further reuse. Disposal is an expensive process and is often problematic from the environmental viewpoint. The following is an overview of the modern oil reclamation approaches.
It should be noted that the process of purification of motor oil occurs in special repair facilities or any other site where extensive quantities of new oil are used, or old oil collected.
Used motor oils are collected separately by types into baths, mobile or stationary drain devices and funnels. Storage is also separate. Used product is stored in barrels or any other closed vessels. When all available vessels are closed, the used product is sent to purification facility.
If the purification equipment operates in one shift, the annual volume of purified oil can be up to 100 tons.
In general case, mineral oils previously used in equipment, tractors, road construction machinery, combines etc can be purified.
Industrial purification and regeneration of motor oils implies intensive influence of high temperatures, acids and alkali. The equipment for purification can be quite complex. The processes can also have a negative effect on the oil. To neutralize such effects, a finishing purification is required to bring the regenerated product to specifications by mixing it with additives.
Industry experts point out that waste motor oils can be restored in most cases for reuse in machines which operate with fewer loads. The required condition for start of regeneration is careful collection of oil to prevent water, dust and detergents from entering the oil.
Purification of used motor oil allows to significantly improve its properties (water content, particulate matter content, acidity, stability, viscosity etc). A correct selection of regeneration methods requires a quick analysis of the product.
The process of used motor oil regeneration consists of several stages: preparation and heating of the product, treating the oil with a special separation agent, coarse purification (settling), fine purification with centrifuges and storage with subsequent dispatch of the product to the customer.
Approaches to purification of motor oil with increased amount of contaminants are different. If a droplet of the product leaves a black stain on filter paper, the proruct must be pre-treated in a reactor tank. The product is pumped into the reactor tank and heated, then finely dispersed separation agent is added to the product. The product and the agent are stirred for 5 – 7 minutes for better coagulation and settling. The suspension then must settle in the reactor for 10-24 hours. The time depends on original degree of contamination, water and detergent content.
Then the oil is treated to remove fine particulate matter and water.
A sample of oil is then analyzed in a laboratory to determine its properties and to choose further reuse.