Common Hydraulic Oil Reclamation Methods

Hydraulic Oil Recycling and Reclamation: A Practical Overview

Learn how hydraulic oil recycling and reclamation reduce waste, extend oil life, and cut production costs. Explore purification, refining, and best practices for maintaining oil quality and sustainability.

Hydraulic oil is the lifeblood of hydraulic systems, serving as the primary means of power transmission, lubrication, and cooling. Its quality directly determines system reliability, equipment lifespan, and operating efficiency.

As industries pursue sustainability and cost reduction, hydraulic oil recycling and reuse have become increasingly important. In China, many large and medium-sized plants now collect and reclaim used hydraulic oil—achieving recovery rates around 80% and successfully regenerating about 70% of degraded oil. This effort has reduced the annual demand for new oil by over 55%, highlighting the economic and environmental value of reclamation.

However, hydraulic oil recycling is a technically demanding process, requiring careful assessment of oil condition, proper treatment methods, and professional equipment.

Understanding Hydraulic Oil and Its Degradation

Hydraulic oil is a blend of base oils and performance additives, formulated to resist oxidation, wear, and corrosion while maintaining stable viscosity under pressure.

Over time, operating stress causes the oil to degrade through:

Oxidation (due to heat and air exposure)

Contamination (water, particles, and sludge)

Additive depletion (loss of anti-wear, anti-foam, or antioxidant agents)

The extent of degradation determines which recycling or reclamation process is appropriate.

Common Hydraulic Oil Reclamation Methods

1. Filtration and Purification (for Reusable Oil)

In most cases, used hydraulic oil primarily contains solid contaminants, water, and sludge, while its base chemistry remains stable. Such oil can often be reclaimed through professional purification systems, which perform:

Fine filtration to remove solid impurities

Vacuum dehydration and degassing to remove moisture and air

Demulsification to separate oil and water phases

After treatment, the oil’s particle count, water content, and cleanliness level can be restored to meet national or ISO standards, allowing it to be safely reused in industrial machinery.

This method is both cost-effective and sustainable, making it suitable for routine maintenance and long-term contamination control.

2. Re-Refining and Re-Additization (for Severely Degraded Oil)

When hydraulic oil becomes dark, viscous, or has a pungent odor, it indicates severe degradation. In such cases, filtration alone is insufficient.

The process typically includes:

Laboratory testing – analyzing acidity, viscosity, and contamination levels

Re-refining – removing acids, heavy metals, and degraded compounds, converting waste oil into a clean base stock

Re-additization – blending with a new additive package to restore its performance properties (anti-wear, anti-oxidation, anti-corrosion, etc.)

This approach essentially regenerates waste hydraulic oil into a near-new condition, enabling it to perform reliably once again.

The Value of Proactive Maintenance

Preventing contamination is always more effective than remediation. Regular use of oil filtration and purification equipment helps maintain oil quality by controlling:

Moisture levels (via vacuum dehydration)

Solid contaminants (via precision filtration)

Acid formation (via deacidification and oxidation control)

Studies show that maintaining a consistent oil purification schedule can extend hydraulic oil life by up to 2 times, significantly reducing both downtime and consumption costs.

Clean oil also ensures better equipment performance, minimizing wear, reducing heat generation, and preventing system failure.

Looking Ahead: Toward Sustainable Hydraulic Oil Use

With the global expansion of hydraulic machinery, demand for hydraulic oil continues to rise, even as petroleum resources become more limited.

The future of hydraulic oil management lies in:

Higher recycling rates through advanced purification and refining technologies

Smarter monitoring systems to detect contamination early

Environmentally responsible oil management to minimize waste and emissions

By embracing hydraulic oil recycling and reclamation, industries can achieve:

✅ Reduced demand for virgin oil

✅ Lower operating and disposal costs

✅ Extended equipment service life

✅ Smaller environmental footprint

Key Takeaway

Hydraulic oil recycling isn't just waste reduction—it's performance preservation.

Through proper filtration, purification, and re-refining, industries can reclaim valuable resources, protect equipment, and contribute to a more sustainable industrial future.