Why You Should Reclaim and Recycle Used Oil

Michael C. Brown, Noria Corporation

Going “green” by becoming ecologically and environmentally responsible is an excellent practice that does not always have to cost your organization money. In many cases, it can actually save money. A number of industries have begun reclaiming or recycling used oil because it makes good business sense. These include automotive manufacturers, steel mills, paper mills, sugar mills, process plants and power generation plants.

Unfortunately, some companies do not reclaim or recycle used oil because they think they don’t have the time to devote to these programs. The engineering/reliability managers of these plants are often so busy managing the day-to-day processes that little or no attention is paid to the total lubricant life cycle, which in most instances would make their process more reliable and less expensive to maintain, especially when it comes to reclaiming oils.

Reclaiming and recycling used oil offers many benefits, such as increased machine reliability, considerable cost savings on oils, less time spent on oil change-outs, reduced environmental contamination and decreased waste disposal costs. Re-refining used oil requires about one-third the energy of refining crude oil to lubricant quality. Also, consider that it takes 42 gallons of crude oil but only one gallon of used oil to produce 2½ quarts of new, high-quality lubricating oil.

Oil Reclamation

Reclamation and recycling are related processes but with significant differences. Reclamation is the act of salvaging, recovering or reclaiming. In this context, the oil is rescued from normal degradation. It generally involves cleaning, drying and adsorption to remove water, acids, sludge and other contaminants. The reclaiming of oil is mostly a nonchemical process that restores an in-service lubricant to good health by removing impurities.

For the most part, reclamation can and should be done onsite to mitigate the chances of cross-contamination. Reclamation may also take place offsite where the vendor of the reclamation service drains the existing oil and replaces it with previously reclaimed oil.

Keep in mind that if the oil is removed from the plant and reclaimed at an offsite location, the potential for cross-contamination increases tremendously. In addition, if an oil spill or accident occurs during transport to the facility, the owner of the oil is liable.

Some oils like motor oils cannot be reclaimed, while others should not be reclaimed due to the costs involved. Additive formulations may be proprietary, or the additives are not easily sourced. There is also the question of whether the reclaimer would be able to finance the liability of equipment damage, downtime and/or bodily harm if there was a mixup with the viscosity or additive formulation.

The best option is to have your newly reclaimed oil tested by a reputable lab to ensure it complies with the machine’s original equipment manufacturer (OEM) specifications before it goes back into service.

Recycling Oil

Recycling is the act of returning something or a part of something back to useful service, which may be different from the original application. Whether it is in an engine, gearbox, hydraulic system or turbine, all lubricant oil eventually reaches the end of its useful life and must be drained from the machine, sump or reservoir.

Some forms of oil recycling can be done onsite. If your plant produces large amounts of used oil that can’t be reclaimed, this used oil can be turned into lubricant oils or fuel for burning in boilers, industrial furnaces, etc. On the other hand, if your used oils must be sent offsite because they are too badly contaminated with different viscosity/base oils and chemicals, or your plant does not have the volume to justify onsite recycling, make certain that the used lubricants are handled and processed in an environmentally acceptable manner by a waste-removal/recycling company.

A number of recycling organizations are available, but you must ensure that you are dealing with a reputable company that processes the oil correctly in compliance with your local laws and U.S. Environmental Protection Agency (EPA) regulations.

What is Used Oil?

The U.S. Environmental Protection Agency (EPA) defines used oil as “any oil that has been refined from crude oil or any synthetic oil that has been used and as a result of such use is contaminated by physical or chemical impurities.”

Oils used as lubricants, hydraulic fluids, heat transfer fluids, buoyants and for other similar purposes are considered used oil. Some examples include engine oil, transmission fluid, lubricating oil, hydraulic oil, gear oil, transformer fluid, cutting oil, tempering or quenching oils, greases and brake fluid.

Used oil does not include oils made from vegetable- or animal-based oils, oil wastes that have never been used (e.g., virgin oil spills), antifreeze, kerosene, or petroleum distillates used as solvents.

Is Reclaiming the Best Option?

Keeping your oils in service as long as possible is beneficial to your business in many ways. The cleaner and drier the oil, the longer your machines will last. Therefore, cleaning your oils while they are still in service and not allowing them to be used to the point of no return (viscosity degradation/oxidization) makes perfect sense. To achieve this, you first must know which oils can be reclaimed.

Typically, reclaimable oils include hydraulic oils, turbine oils, circulating oils for bearing lubrication, paper machine oils, gear oils, quench oils, some metalworking fluids, transformer oils, some synthetics and several specialty fluids.

Next, you need to determine your oil’s remaining useful life through oil analysis. Do not just rely on interval-based oil changes for your reclamation program. You may be leaving the oil in the machine too long. Employ a quality laboratory to conduct the testing and make sure you have a baseline sample from the new oil as a reference for the viscosity, cleanliness and additive levels. This will help you discover what’s happening to the oils in your machinery and how their life is being impacted.

The oil should be tested for the following:

  • Viscosity at 40 degrees C (ASTM D445)
  • Acid number (ASTM D664)
  • Rotating pressure vessel oxidation test (ASTM D2272)
  • Water separation at 130 degrees F (ASTM D1401)
  • Trace metals analysis (ASTM D5185)
  • Cleanliness level standards (ISO 4406:99)
  • Pressure differential scanning calorimetry (ASTM D6186)

Plant personnel should be trained to read sample reports and to take samples correctly with the right equipment. You may need to outfit your machinery with better breathers, quick connects and filters to keep as much contamination out of the machines/systems as possible.

Reclamation involves the oil being filtered and cleaned of debris, sludge and fine particles. Centrifuging is also used to remove suspended particles and some water. Many oil reclamation units dry the oil by heating it and applying a vacuum. Vacuum dehydrator units can be utilized onsite and are great assets if the costs can be justified. If not, you will need to have your oils reclaimed offsite.

Selecting a Reclamation Company

To help determine a prospective reclamation company’s credibility and expertise, it is important to ask a few simple questions, such as whether the oil is tested before and after it is reclaimed, if particle count data is provided at the site during reclamation, what the cost savings associated with reclamation are, if the oil can be refortified legally and accurately onsite, whether the original formulators are involved, and how the reclamation will impact the machine’s warranty.

In conclusion, all plants should have a coordinated plan for managing used lubricating oil, including how much oil is reclaimed and how much is recycled. Cleaner production methods and a focus on minimizing waste are the first steps to reduce used oil.

However, once the oil reaches the end of its useful life, it should be either reclaimed or recycled. If reclaimed, the oil may continue to serve its designed function for many more operating hours. Rigorous testing and record-keeping will be necessary for this approach.

If the used oil is a mixture of contaminants and waste oils or has been severely degraded and cannot be reclaimed, then it should be reprocessed by a recycler or repurposed into fuel. Of course, all of this is dependent on the type of contamination in the used oil.

Finally, be sure to follow all local laws and the EPA’s regulations for used oils. If you do not, harsh fines may be imposed.

61% of industrial plants reclaim or recycle used oil, based on a recent poll at MachineryLubrication.com

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About the Author

Michael C. Brown is an industrial services technician with Noria Corporation. He has more than 20 years of experience in heavy manufacturing and holds Machine...