Turbine Oil Regeneration

In the power generation industry, turbine oil regeneration plays an important role in preserving one of the most critical and costly assets. Turbines represent a significant investment, requiring substantial financial resources, making the proper servicing and maintenance of these machines a top priority. One of the most essential aspects of turbine maintenance is lubrication, as turbine oil acts as the lifeblood of these machines. High-quality turbine oil can last for over a decade; however, due to the harsh operating conditions in which it functions, it may begin to degrade prematurely.

Factors such as high temperatures, contamination, and oxidative stress contribute to oil aging, which can affect the performance and safety of the entire turbine system. For this reason, regular monitoring and regeneration of turbine oil are essential practices for maintaining optimal turbine performance and preventing unexpected downtime.

Causes of Aging of Turbine Oils

During the operation of turbine units, oil gradually undergoes significant changes, commonly referred to as “aging,” which involve alterations in its chemical and physical properties. Turbine oils are primarily composed of hydrocarbons, and their aging occurs as these hydrocarbons come into contact with oxygen in the air. This process is accelerated by catalytic reactions with water and metals and is further intensified by increasing temperatures. As oxidation progresses, the oil undergoes a number of key changes:

• Density and viscosity increase.

• Demulsifying ability deteriorates.

• Acidic and volatile products form, leading to corrosive tendencies.

• Dense oxidation products precipitate, resulting in sludge formation.

• The oil darkens due to the accumulation of oxidation by-products.

In the absence of oxygen and water, oxidation reactions do not occur. However, when oxygen diffuses into the oil, conditions such as spraying, splashing, and foaming promote rapid oxygen dissolution, reaching an equilibrium concentration (around 4 % by volume for petroleum-based turbine oil). This state accelerates the aging process to its maximum rate.

While oxidation can occur even at indoor temperature or below 32 °F, it progresses much faster at elevated temperatures. Under such conditions, even minimal oxygen presence can trigger the rapid formation of acidic products. Notably, every 10 °F increase above 230 °F nearly doubles the oxidation rate. Moreover, oxidation products can act as catalysts, further accelerating the oil aging process. Experience shows that mixing new oil with oxidized or sludge-containing oil does not inhibit oxidation; instead, it can intensify the process within the mixture.

Turbine oils, especially those used in steam turbines, are intended to last between 10 and 20 years, but are subject to gradual degradation. This deterioration creates challenges for operators seeking to maintain oil performance under harsh operating conditions and to prevent unplanned equipment downtime.

Over long-term operation, turbine oils in lubrication systems undergo significant changes that impair their functional properties. The three main factors contributing to this degradation include:

• Contamination with mechanical particles.

• Oxidation of the oil.

• Water ingress into the oil.

These factors are often interrelated and collectively affect oil quality. The primary indicator of oil degradation is an increase in its acid number (AN), which measures the concentration of acidic constituents in the oil. The acid number indicates how many milligrams of potassium hydroxide are required to neutralize 1 gram of oil (mg KOH/g).

For example, new high-viscosity-grade oil has an acid number of approximately 0.02 mg KOH/g, whereas waste oil may exhibit a significantly higher value, such as 0.98 mg KOH/g, indicating a high degree of aging.

Fluidex Turbine Oil Regeneration Technology 

For countering the negative effects of oil aging, regeneration technologies have been developed to restore the original properties of turbine oil and extend its service life. One such advanced turbine oil regeneration technology is Fluidex, implemented in the FLD 12R machine, which provides an efficient and environmentally friendly solution for reclaiming degraded turbine oil. 

The Fluidex regeneration technology helps mitigate operational risks while preserving natural resources. The equipment operates based on the principle of adsorptive purification, where contaminants are removed using a regenerable sorbent. Once saturated, the sorbent can be reactivated and reused multiple times. Typically, it can withstand between 500 and 700 regeneration cycles, which corresponds to several years of continuous operation.

After reaching the end of its service life, the sorbent remains environmentally safe. It can be disposed of as standard construction waste or even reused as a soil conditioner to improve soil structure.

The adsorbents used in the FLD 12R machine are highly efficient and intended for repeated use, ensuring long-term, reliable oil purification with minimum environmental impact. This approach makes the technology not only cost-effective, but also environmentally sustainable.

Benefits of Turbine Oil Regeneration

Turbine oil regeneration, as an alternative to oil replacement, delivers multiple benefits:

• Extended service life of oil: regeneration removes contaminants and restores chemical balance, significantly extending the useful life of oil and reducing the frequency of oil replacement.

• Cost savings: by regenerating used oil, companies avoid the high costs associated with frequent oil replacement, as well as maintenance costs caused by degraded oil.

• Environmental sustainability: regeneration conserves natural resources by reducing the need for new oil production and disposal, thereby lowering the environmental footprint of power plants.

Power generation facilities depend heavily on reliable turbines to ensure continuous electricity production. The aging of turbine oil leads to the formation of harmful by-products such as acids, sludge, and emulsions, which can severely compromise turbine performance if left unaddressed.

The Fluidex turbine oil regeneration technology, used in FLD 12R machines, offers an effective and sustainable solution for reclaiming degraded turbine oil. By removing contaminants, oxidation by-products, and moisture, this technology helps extend the service life of turbine oil, reduce maintenance costs, and support environmental sustainability. Through regular oil analysis and regeneration, power plants can ensure reliable turbine operation, minimize downtime, and maximize efficiency.