In recent years, ecological conservation and environmental concerns have become significant influences on production facilities around the world. Progressive actions can now be found right at the center of major industrial operations, including in steel, paper, and sugar mills as well as different processing plants. These industries are focusing on regenerating, reclamation, and recycling used lubrication oil in a profitable yet ecologically-sound manner.
Often, the technical manager of large plants is so busy managing production and ensuring there is minimal downtime occurring that very little attention is paid to the plant’s total lubricant cycle. This is in part due to how the life cycle is set up. Often, the plant’s purchasing department orders the lubricating oil based on price. A separate department, the handling and storage department, then ensures the lubrication is disposed of through a waste removal company. At every step, the manager is further removed from the process; they need to be proactive about their procedures, especially when conservation and reclamation come into the conversation.
Various local, state, and federal authorities have set regulations concerning the proper handling and disposal of lubricating oils. This includes the Environmental Protection Agency (EPA), which has also issued used-oil-management standards that state regulatory officials are required to implement.
There are a number of ways to follow these standards, such as selling the used lubricating oils to a recycling plant where they will be recycled into fuel oil or base oil stocks. The site could also reclaim its own oil and have it for in-plant usage. Oil reclamation is the process of taking used lubricating oils, rehabilitating them, and returning them to a like-new condition.
When oil is reclaimed, you:
- Conserve a valuable resource.
- Prevent environmental contaminations.
- Save money by reducing waste disposal costs.
- Reduce long-term liability for disposed-of products.
When to recycle, reclaim, or regenerate
Reclamation and recycling are related processes, but there are significant differences between the two.
Recycling is the process of taking the lubricating waste and transforming it into a product that can be used for a host of different uses. Every lubrication oil charge will eventually reach the end of its life. When this happens, the oil needs to be drained from the machine system. From here, the oil is recycled, and either gets refined into a new base oil or is treated and sold as fuel oil.
The plant engineer doesn’t need to be concerned about what kind of technology is used for recycling since plants typically send their lubricating oil off to be recycled. It is important, however, that the plant engineer ensures the recycled lubricants are handled and processed in an environmentally acceptable manner. This can be accomplished by asking the removal company to produce a copy of an independent environmental audit of its site and processes. This is also when the plant engineer should ensure the company is properly licensed to process used oil. The engineer should also consider making regular visits to the site to ensure proper protocols are being followed.
With the goal of returning an oil to a like-new condition, reclamation can be a great asset to any plant. Reclamation treats a charge of lubricating oil and returns the charge to the machine sump. Reclamation generally involves cleaning, drying, and adsorbing to remove color, acids, and sludge. It is essentially a nonchemical process that restores in-service lubricating oil for reuse in a system.
It is preferable to have this process happen on-site, but it can also be taken off-site, where a vendor drains the existing charge and replaces it with previously reclaimed oil.
One of the more advanced ways to treat your in-service oil is to regenerate it. While oil regeneration is a newer technology, there are already companies offering regenerative solutions to help plants around the world go beyond oil recycling and reclamation. Oil regeneration allows us to stop treating industrial oils as a consumable product and instead start caring for them as a long-term asset in your maintenance and reliability program.
Unlike recycling, where the contaminated oil is shifted to a different application, oil regeneration focuses on keeping the oil in a like-new state. Through processes such as our double-separation technology (DST), combined with additive top-ups and other treatment methods, oil regeneration maintains oil in a highly clean state that allows it to be continually reused, potentially indefinitely. In some applications, the same oil can be used for years and years with performance characteristics that are equal to or better than “new” oil shipping in from a standard supplier.
This shift towards oil as an asset represents an exciting and disruptive change in the lubrication industry because it allows plants to simplify many of their processes. Regenerating your oil makes it possible to:
- Extend oil life significantly
- Lower associated labor costs for oil changes, storage, etc.
- Maintain oil in a highly clean state that extends component, seal, and asset life
- More predictable and consistent cost structure (less affected by shipping or supply chain issues and oil price volatility)
Oil reclamation and regeneration in practice
Turbine oils and hydraulic oils lend themselves to being reclaimed or being filtered and cleaned of debris, sludge, and fine particles. Transformer oils also are often maintained in similar ways, but it is important to ensure that the lubricant’s performance hasn’t been negatively affected by the reclamation or regeneration process.
Hydraulic oils are a complex mixture of carefully selected base oils and specific additives. Top-tier hydraulic oils, often called antiwear hydraulic oils, must meet performance specifications set by the original equipment manufacturers (OEM), hydraulic pump makers, and standards organizations such as the American Society of Testing and Materials (ASTM).
Plant engineers are increasingly interested in extending the life of their hydraulic fluids. As a result, suppliers and consultants are often asked about how to carry this out.
Because of their high-pressure operations, hydraulic oils tend to accumulate silt. This silt must be eliminated to prevent valve sticking and polishing wear. Hydraulic oil is reclaimed through a combination of filtration, vacuum dehydration, and adsorption. This combination results in the removal of fine particles, sludge, and water, while simultaneously regenerating the performance level.
When considering a reclamation service for hydraulic oil, make sure to:
- Ensure reclamation vendors can show proof of previous successes.
- Obtain a certificate of analysis from the vendor at the end of the reclamation.
Compare this to the condition of the oil before the reclamation.
- Understand the performance capabilities of the new oil and the performance requirements of the OEM.
- Perform quality tests through an independent lab to verify beginning and ending oil conditions and performance characteristics.
- File test certificates and records for the next oil change.
Great care must be used when reclaiming turbine oil. While centrifuging and filtration will remove particles and water, the turbine oil must also continue to perform its duties, such as cooling, sealing, lubricating, and preventing corrosion. Even though the application is critical, turbine oil sump volumes warrant the reclamation effort.
The key to turbine oil reclamation is evaluating its performance under specific test procedures. Turbine oil is reclaimed using a combination of filtration, fresh oil sweetening, and additive sweetening. To sweeten something is to ensure it is low in sulfur. This combination results in fine particle, sludge, and water removal as well as the regeneration of the oil’s performance level.
When considering a reclamation service for turbine oil, make sure to:
- Ensure the lubrication supplier is working closely with you on testing and recharging.
- Obtain a test certificate on the performance of the new oil.
- Test reclaimed oil prior to refilling to ensure compliance with performance targets.
- Check the compatibility — up to fifteen percent of the old charge can remain in the turbine system.
- Perform quality tests through an independent lab to verify beginning-to-end oil conditions and performance capabilities.
- Verify oil performance after reclamation using bench tests such as the Rotating Pressure Vessel Oxidation Test (RPVOT) (ASTM D2272).
After finding a reputable and trusted reclamation or regeneration solution provider, the key is to assemble a reclamation team to manage the process.
Assembling your team
Managing lubrication recycling, reclamation, or regeneration activities is often neglected in plants today. But if there is a sufficient volume of used lubrication at the site to justify reclamation, it is extremely helpful to form a team to focus on this process. A recycling and reclamation team can consist of a combination of any of the following:
- Lubrication engineer
- Maintenance engineer
- Lubrication supplier representative
- Reclamation company representative
- Environmental officer
Used oils should be broken into two categories — either regeneration/reclamation or recycling. The plant manager will have to make the ultimate decision between regeneration/reclamation and recycling. But because lubricants have different processing requirements, some lubricants are not good candidates for regeneration or reclamation. If it’s not clear whether the used oil stream is a good candidate for these approaches, contact your solution provider to learn more about what lubricants are most compatible with their technology.
Lubricants that may need further research to decide if they are a good candidate for regeneration or reclamation include:
- Cutting fluids
- Hydraulic oils
- Turbine oils
- Transformer oils
Using Recycled Oil
There are several things that industrial plants around the world tend to do with waste oil, including:
- Burning it without treatment, although this is not advised.
- Reprocessing it into an industrial fuel.
- Re-refining it into a new lubrication oil.
- Disposing of it at a landfill, but again this is far from ideal.
Unless they are being regenerated to a “like new” state, all lubricants eventually reach a condition where they can no longer be used and must be discarded as used lubricating oil, the plant engineer has options available to minimize the volume of used oil being generated, such as:
- Using in-line oil sensors to ensure that the oil life is extended and unnecessary oil changes are not occurring.
- Using an oil mist lubrication on industrial gearboxes and other equipment.
- Choosing an extended drain period diesel engine oil for fleets.
- Selecting equipment with reduced oil sump sizes.
- Improving the filtration of the lubrication oil charge and dosing with additives.
- Preventing oil charge contamination.
Every plant should have a coordinated plan for managing used lubricating oil. Cleaner production methods and waste minimization should be the first initiatives in reducing waste oil at a factory. But whether you are continually regenerating oil or waiting for it to reach the end of its design life to reclaim or recycle it, these practices can help you decrease oil consumption and mitigate the environmental impact of lubricants in your operations.