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102
Chapitre Entretien
General Fuel Information
• Crankcase oil fuel dilution can be higher when
biodiesel or biodiesel blends are used. This
increased level of fuel dilution when using
biodiesel or biodiesel blends is related to the
typically lower volatility of biodiesel. In-cylinder
emissions control strategies utilized in many of the
industrial latest engine designs may lead to a
higher level of biodiesel concentration in the
sump. The long-term effect of biodiesel
concentration in crankcase oil is unknown
currently.
• Perkins recommend the use of oil analysis to
check the quality of the engine oil if biodiesel fuel
is used. Ensure that the level of biodiesel in the
fuel is noted when the oil sample is taken.
Performance-Related Issues
Due to the lower energy content than the standard
distillate fuel B20 will cause a power loss in order of 2
to 4 percent. In addition, over time the power may
deteriorate further due to deposits in the fuel
injectors.
Biodiesel and biodiesel blends are known to cause
an increase in fuel system deposits, most significant
of which are deposits within the fuel injector. These
deposits can cause a loss in power due to restricted
or modified fuel injection or cause other functional
issues associated with these deposits.
Note: Perkins T40-0012 Fuel Cleaner is most
effective in cleaning and preventing the formation of
deposits. For more information refer to "Perkins
Diesel Fuel System Cleaner, and Perkins".
Biodiesel fuel contains metal contaminants (sodium,
potassium, calcium, and/or magnesium) that form
ash products upon combustion in the diesel engine.
The ash can have an impact on the life and
performance of aftertreatment emissions control
devices and can accumulate in DPF. The ash
accumulation may cause the need for more frequent
ash service intervals and causes loss of performance
General Requirements
Biodiesel has poor oxidation stability, which can
result in long-term problems in the storage of
biodiesel. Biodiesel fuel should be used within 6
months of manufacture. Equipment should not be
stored with the B20 biodiesel blends in the fuel
system for longer than 3 months.
Due to poor oxidation stability and other potential
issues, it is strongly recommended that engines with
limited operational time either not use B20 biodiesel
blends or, whilst accepting some risk, limit biodiesel
blend to a maximum of B5. Examples of applications
that should limit the use of biodiesel are the following:
Standby Generator sets and certain emergency
vehicles.
For standby generator sets and emergency vehicles
that cannot avoid use of biodiesel blends fuel quality
in the engine fuel tank must be sampled and checked
monthly. Test should include acid number
(EN14104), oxidation stability (EN 15751 commonly
know as the Rancimant test), and sediment
(ISO12937). For standby generator sets oxidation
stability of biodiesel blend must be 20 hours or more
as per EN 15751. If the test shows that the fuel has
degraded, fuel tank must be drained and engine
flashed by running with the fresh high-quality diesel
fuel.
Perkins strongly recommended that seasonally
operated engines have the fuel systems, including
fuel tanks, flashed with conventional diesel fuel
before prolonged shutdown periods. An example of
an application that should seasonally flush the fuel
system is a combine harvester.
Microbial contamination and growth can cause
corrosion in the fuel system and premature plugging
of the fuel filter. Consult your supplier of fuel for
assistance in selecting appropriate anti-microbial
additive.
Water accelerates microbial contamination and
growth. When biodiesel is compared to distillate
fuels, water is naturally more likely to exist in the
biodiesel. Therefore check frequently and if
necessary, drain the water separator.
Materials such as brass, bronze, copper, lead, tin,
and zinc accelerate the oxidation process of the
biodiesel fuel. The oxidation process can cause
deposits formation therefore these materials must not
be used for fuel tanks and fuel lines.
Renewable and Alternative Fuels
Perkins supports development and use of renewable
fuels through sustainability initiatives. In recent years
various forms of renewable and alternative
(synthetic) diesel fuels have started to emerge.
Synthetic diesel fuels are produced by gasification of
various feedstock and then synthesis to liquid to
obtain paraffinic diesel fuel. Based on the feedstock
used these fuels are commonly referred to as
Biomass to liquid (BTL), Gas to liquid (GTL) and Coal
to liquid (CTL). Hydrotreating of vegetable oils and
animal fats is another emerging process for
production of bio based diesel fuel called
Hydrotreated Vegetable Oil (HVO).
BTL and HVO fuels are considered to be low carbon
fuels as they reduce carbon foot print compared to
fossil fuels and are commonly referred to as
renewable fuels. These fuels must not be confused
with biodiesel FAME which is fundamentally different
fuel and is discussed in a separate section in this
manual.
SFBU9063-10
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