Oil Degrades of Biokem
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OIL DEGRADES BIOKEM
When oil is used in a machine, the oil will
degrade slowly during use over a period of time,
depending on the type of lubricant, operating
temperature, operating conditions and the
physical environment.
Lubricant degradation has negative effects on
system lubrication and for example, hydraulic
system pressures; these problems can result in
serious consequences for the equipment
performance and reduce reliability leading to
breakdowns.
New lubricants are a formulation of base oil and
chemical additives. Lubricant additives are
present to counteract the majority of ill effects
that contaminants cause.
Oil Refiners (Shell, Exxon-Mobil, etc.) produce
base oils that can be categorised into groups
which gives an indication of its oxidation
characteristics. Where longer life is required,
Group II, Group III and Group IV base oils are
used by lubricant manufacturers.
The Group of oil used is determined by the
Original Equipment Manufacturers recommendations to satisfy the OEM
requirements for equipment service and
warranty purposes.
Lubricant additives play a critical role in
preventing lubricant degradation. The additives
are essentially sacrificial in their role of
protecting the base oil because the additives
will degrade first while minimising any
degradation to the base oil molecular
properties.
After additive content is consumed by
operational forces, the integrity of the
hydrocarbon base oil becomes compromised
because it is no longer protected by additives.
At this point lubricant oxidation and the
consequent tell-tale discolouration
commences.
In short, the modern lubricant has been
designed and formulated to meet the harsh
operating environment of modern equipment.
Contaminants can unbalance the lubricant and can result in less than optimum
performance in its duty, increasing equipment
damage which can ultimately lead to
breakdowns.
Types of lubricant additives
include:
· Antioxidants (anti-oxidation)
· Antiwear agents
· Viscosity index improvers
· Rust/corrosion inhibitors
· Demulsifiers
· Extreme pressure additives
· Antifoam agents
· Detergents/dispersants
Additive depletion and
oxidation
Antioxidant additives are the key to extending
your lubricants remaining useful life by significantly limiting lubricant degradation from
occurring, but antioxidants are depleted in the
process.
Being sacrificial, antioxidants deplete first
before the base oil begins to oxidise and studies
have shown that once 70% of the antioxidant
additives in new oil have been depleted,
physical changes within the lubricant begin to
occur.
The resulting lubricant oxidation increases the
lubricant viscosity, Total Acid Number (TAN)
and the formation of sludge and varnish.
By monitoring the antioxidant content of
lubricant, Biokem detects additive depletion in
advance and prevents lubricant oxidation,
thickening and acid and varnish formation.
The additive depletion and oxidation reaction is
accelerated by a number of factors, primarily:
High operating temperatures
Moisture contamination
Particle contamination
High Operating temperatures
High operating temperatures in the form of
mechanical and thermal energy both produce
heat which will accelerate lubricant
degradation. Heat generated by operating
equipment is unavoidable, but excessive heat
will lead to increases in the consumption of
antioxidant additives. The rate of lubricant
oxidation doubles for every 10°C rise in
operating temperature above 100°C.
Moisture contamination
Water contamination adversely affects the
lubricants by acting as a catalyst for oxidation and
causes rapid additive depletion. Water will react
with many oil additives, fracturing the additive into
two or more chemical fragments. Water also
promotes rusting, corrosion and filter plugging.
Common sources of water contamination are heat
exchangers and seal leaks, condensation,
inadequate reservoir covers and temperature drops
that lead to dissolved water becoming free.
Particulate contamination
Particulate contamination occurs in many forms
within in-service oil, causing abrasive wear,
fatigue and erosion. Additional contamination
is evident whenever dirt particles circulate
through the system at high pressure and at high
speed.
Airborne dirt particle contamination is a major
contamination source. Light enough to float in
air these particles can be introduced in exposed
reservoirs as the oil level goes down. Oil
reservoirs with levels that change frequently are
most at risk to large amounts of dirt and
airborne contamination. This is commonly how
new oil delivered from oil companies becomes
contaminated.
Particulate contaminated lubricant provides reduced lubricating properties and increases friction that results in heat generation.
During oxidation, polymerisation causes sticky molecular structures, commonly referred to as sludge . Sludge is a resinous like substance
that is darker in colour and leaves deposits throughout the entire lubrication system. Sludge is often why lubricant will darken during its time in use.
With sludge molecules being microscopic in
size, the molecules are not removed by some
traditional filter systems. Combined with their
sticky molecular structure and corrosive effect,
lubricant sludge will directly affect the reliability
and efficiency of all systems it is found within.
Oxidation by-products cause more oxidation,
starting a cycle where the more by-products are
present, the faster oxidation accelerates.
Quickly the level of oxidation will reach a point
where the lubricant becomes destroyed by a
change in its molecular structure and must be
replaced with new oil.
Preventing lubricant
Oxidation
Rapid lubricant degradation will occur when the
additive quantity falls below critical level, at this
point the rate of oxidation will increase due to
the lubricant not having enough additives to
counteract oxidation.
The PROPEL Oil Management process includes
monitoring of active antioxidant additive to
determine the level of lubricant remaining
useful life (% RUL), moisture contamination and
particulate cleanliness level.
By lubricant condition monitoring and renewal,
additive levels do not deplete below critical
levels, preventing lubricant degradation and
waste. PROPEL Oil Management will renew
lubricant to as good as new specification (or
higher) before oxidation occurs, preventing
costly lubricant replacement.
PROPEL Oil Management – Professionally
Renewed Oil Prolongs Equipment Life.