fuel oil is used in Diesel engines, several residual compounds are formed,
including Sodium Vanadates,
which are highly corrosive as they are in a liquid state at temperatures of
between 350º and 650ºC, according to the molar ratio of Vanadium to
Sodium of the compound formed (See Dossier
rb, Section B , page 8).
has been amply explained in our technical documentation on the subject of
corrosion, during the combustion of fuel oil the presence of these Sodium Vanadates
causes corrosion at every point of the exhaust gas circuit of a Cogeneration
Plant, wherever the temperature is in excess of 340º - 350 ºC, and the
effect is ever more damaging the higher the content of vandates
and the higher the temperature.
phenomenon is the cause of corrosion on:
The Exhaust Valves of the engine
Heat exchangers of the related boilers
where the temperature of the inlet gases is usually between 350ºC and 390ºC,
or even slightly higher.
corrosive effects are produced when
the engine is warm, i.e., while the engine is running continuously, and can be more severe on the heat exchangers if the engine is stopped
repeatedly, given that at standstill, in addition to corrosion by vanadates, there may occur corrosion due to acidity of
the encrusted residues, mainly produced by the presence of SO3 in the
residues which gives rise to corrosive sulphuric acid below 160ºC.
bertomeu” beco F1/ASF
has been demonstrated to be fully effective in neutralising all these effects
of corrosion, and no other additive is able to guarantee the same tried and
treatment of fuel oil with our additive “rb bertomeu” beco F1/ASF works
on two basic factors during the combustion of fuel oil:
a) It changes the composition of the Vanadates, thereby raising their melting point and eliminates their corrosive effect at
the operating temperatures of valves, turbos and
b) It minimises the catalytic effect
that Vanadium from the fuel oil has in the oxidising of SO2 into SO3, and
thereby reduces the presence of SO3
in the exhaust gases and consequently the liability of the formation of
corrosive sulphuric acid as the temperature drops.
For more information, please read the document "RB-8 Anticorrosive efect of the heavy fuel oil additive “rb bertomeu” beco F1/ASF"
Both these factors are
key the prevention of corrosion on exhaust valves, on turbos and on
the exhaust gas side of boiler
heat-exchangers in power plants with Diesel engines running on
fuel oil, both when the engines are
running, and during standstill
when the engines are not in continuous operation.
have checked the operating logs and incident reports available in our
database which relate to cogeneration plants running on fuel oil that
regularly use our additive “rb bertomeu” beco F1/ASF and
we have not found a single plant where corrosion has occurred on the turbos nor on
the steam boilers, while the valves have suffered only the
slightest of superficial corrosion which is removed at engine overhauls. This
means the life in service of these components is tripled, as measured against
installations where beco F1/ASF is not used.
For more information, please read the study "Minera de Santa Marta power plant. Valve savings historical data."
Equally, to give a common example
about the extension on the TBO (time between overhaul) of an engine
exhaust valves until doubling the normal value,
we can mention the tests, carried out in collaboration with the plant owner
and the engines manufacturer , along 2000-2002, in a power plant
equipped with engines Deutz BV 16M 640 running on fuel oil (See
our report RB-13 Energyworks-Carballo extension of the useful life of exhaust valves up to doubling TBO (Time between overhauls) ). Most relevant
data of that test are the following :
Beginning of tests : 2000
End of tests : 2002
Engine power : 6.3 MWhe
Fuel : heavy
Fuel additive : "rb bertomeu" beco F1/ASF
Exhaust valves installed in the
engine for the tests : New : 6
Reconditioned : 26
TBO : 203
% of normal TBO (normal TBO + 103 %)
The test was given as concluded
when the objective of doubling normal TBO was reached.
Exhaust valves changed during the
test, between TBO 0 % and TBO 150 % : 0
Exhaust valves changed during the
test, between TBO 150 % and TBO 203 % : 3
Reusable exhaust valves at the end
of tests : 31 (96.8 %)
Non Reusable exhaust valves at the
end of tests : 1 ( 3.2 %)
comparative analysis of the differences
in corrosion which exist between engines and boilers in cogeneration
plants that regularly use our additive for fuel oil “rb bertomeu” beco F1/ASF and other similar plants that either do
not use treatment for fuel oil or an inferior treatment, are worthy of
several comments of a general nature:
In power plants where the
bertomeu” beco F1/ASF
is used there is no corrosion detectable on the heat
exchangers of the boilers nor on the turbos.
The slight corrosion on the exhaust valves has been discussed in previous
studies and is very much lower than that found where our additive beco F1/ASF is not used.
The absence of corrosion, when our
treatment is applied, is based on the elimination of corrosive vanadates at relatively low temperatures (340-380ºC) that
are present in turbos and boiler heat exchangers
(higher on the exhaust valves of the engines) as well as on reduction to a
minimum of the oxidisation of SO2 into SO3.
In power plants where our treatment for
fuel oil is not used, although we do not have operating data at our
disposal, we do have considerable
experience contributed by our customers who have turned to using our
additive beco F1/ASF after finding corrosion at
various points of the exhaust gas circuit, mainly on exhaust valves and turbos. The following are some of the more relevant
1- In practically all the engines substantial corrosion appears on the exhaust
valves. The degree of corrosion is such that many of the valves have to be
replaced due to blowouts occurring before the general maintenance stoppage,
and those that pass the complete TBO have such high levels of corrosion that
the necessary adjustment is severe and means that the valve may only be
re-used once or twice (four to six times when our treatment with beco F1/ASF is used).
2- The fact that the valves in an engine affected by corrosion may be of a
different material to those in other engines, or reconditioned valves (used
previously in other engines and later corrected) ought not to suppose a
significant difference in the occurrence of corrosion as detected in
practice. In fact, in many of the engines using our treatment “rb bertomeu” beco F1/ASF, reconditioned valves are used, while
still complying with scheduled TBOs (or even higher
periods of time). (Please read our techincal document RB-24 The additive “rb bertomeu” beco F1/ASF and the increment of the useful life of reconditioned exhaust valves, in diesel engines using heavy fuel oil )”
3- A blowout is basically severe corrosion on certain
point of the valve seat, which may be due to defects in the rotocap or localised defects in the material of the
valve, but may also be aggravated by a lower level of anti-corrosion
protection in the treatment of the fuel oil, given that the corrosive vanadates formed in this case accelerate the corrosion
triggered by such defects, and end in perforating or blowing out the valves
before the TBO is due.
4- Regarding possible corrosion on the
boiler heat exchanger, we may say that if corrosion appears during
continuous operation it means that the fuel oil is not being treated, or that
the treatment used is not as effective as our additive beco F1/ASF, which has prevented all corrosion at this point, both in
continuous operation and in discontinuous operation, wherever it has been
On the other hand, in some plants tests have been
made with an additive of the type
combustion finalizing or combustion catalyst in the flow of gases
entering the boiler (in order to reduce soot and organic unburned residues
which dirty the heat exchangers of the boilers) which would obviously
encourage the oxidisation or complete combustion of the all the unburned or
partially burnt compounds that may be present in the exhaust gases of the
engines, e.g. hydrocarbons, carbons and CO, but also of SO2, which would
oxidise to SO3 aggravating corrosion during stoppages with discontinuous
operation. It has also been observed that the injection of certain types of
additive causes greater dirtying of the boiler heat exchangers, defeating the
object of cleaning them.
5- In the case of newer co-generation Plants, with a few thousand hours in
operation, corrosion on the turbos will not have been still detected at this stage
in any of the engines, as corrosion develops over a longer period than on the
exhaust valves. Our experience in this area, which we hope is useful to
yourselves, is as follows:
5.1 Several of our customers with Cogeneration Plants have had to replace turbos or parts of them, when corrosion appeared after a relatively low number of
hours in operation (12,000 – 14,000) , before applying our additive treatment for fuel oil.
5.2 The application of the additive “rb bertomeu” beco F1/ASF has eliminated corrosion on the turbos, as well as reducing incrusted residues. We have customers whose engines have reached over 40,000 hours in operation with the original turbos.
5.3 If the appropriate anti-corrosion treatment
is not applied, corrosion on the turbos is
inevitable, especially if corrosion has been detected on the exhaust
valves and on the boiler heat exchangers, as the corrosive compounds present
in the exhaust gases are the same and the temperatures are quite similar.