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Somehow it doesn’t even seem possible that used motor oil can be recycled and reused.  It doesn’t seem possible because used motor oil is such awful, messy stuff that it’s hard to imagine how anyone could really clean it. But it can, and millions of gallons of it are recycled every year – thankfully keeping it out of waterways and landfills across the country.  Here’s how it all works.

Used motor oils are collected from places that “change oil,” this includes, garages, dealerships, Jiffy Lubes and from various commercial operations. From there it is usually loaded into 18 wheel tanker trucks and transported to special chemical processing facilities called “Re-refineries.” Re-refineries are specialized oil processing plants are structurally similar to standard petroleum refineries but are designed to process used motor oil.

How it’s done

Recycling used motor oil occurs through a series of sequential separation steps, each of which removes a particular component in the used oil.

The first step in the recycling process is removing any water from the used oil. Since “oil and water don’t mix”, this process is the easy part.  The water is extracted and thoroughly cleaned. Next the lighter components are pulled from the mix and these highly flammable fuels are actually used to power the refinery. The next step is to remove any ethylene glycol. Ethylene glycol is the primary component in most automotive antifreeze mixes. This contaminated ethylene glycol is then cleaned up and processed for re-use in recycled antifreeze.

Then a process called “vacuum distillation” is used to remove the portion of the oil suitable for reuse as lubricating oil.  This leaves other heavier oils and other combustion by-products for use in road paving. The extracted lubricating oil next undergoes hydro-treating to remove residual polymers and other chemical compounds, and to saturate carbon chains with hydrogen.

Then the remaining oils are separated

The final oil separation, or “fractionating,” separates the oil into three different oil grades. The first are light viscosity lubricants suitable for general lubricant applications, then low viscosity lubricants for automotive oil use, and finally high viscosity lubricants for heavy-duty applications such as grease and thick oils.

Part of the final production steps involves blending detergents and many other additives into the three grades of oil products. Then each product is finally tested for quality and purity before putting it into containers for retail sale.

As you can see, the original “hopelessly” contaminated oil is indeed cleaned up and reused.  This is a win-win for everyone.  Not only is it not necessary to pump out new oil from the ground, old oil isn’t discarded haphazardly.

Article Courtesy of: Ken Garff West Valley


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