Technical Issues

Fuel Switching
Lanfranco Benedetti - CESA
Tripartite 2010 - Tokyo
Some Regulations:
(1) Article 4b of "EU COUNCIL DIRECTIVE 1999/32/EC of 26 April 1999 relating to
a reduction in the sulphur content, introduces 0.1% sulphur limit (m/m) for
marine fuel.
a. Effective Date: January 1, 2010
b. Applies to: All types of marine fuel used by ships at berth for more than two
hours in EU ports unless an approved emission abatement technology is
employed or shore power is available
(2) California Air Resources Board (CARB)
a. Effective Dates:
Phase I (in force) since July 1, 2009 (ISO 8217) at or below 1.5%S or (ISO 8217) at
or below 0.5%S
Phase II - January 1, 2012 (ISO 8217) at or below 0.1%S
b. Applies to: All types of marine fuel used by ships within California Waters
Why Low Sulphur?
First the chemical reaction
Conversion Mechanism from Sulphur Dioxide to Suphuric acid
Sulphur Trioxide and Sulphuric Acid in aerosol form damaging
Health and Environment
Second: Sulphur effect on us
Allergen - Asthma
Trigger - Respiratory (breathing) effects
Constrict airways – Wheezing- Chest Tightness - Coughing
Chronic exposure may cause Bronchitis
High Concentrations can cause Severe Shortness of Breath
Pulmonary Edema
Fluid in the Lungs.
Those most sensitive are children, the elderly
Long-term exposure to low concentrations can cause headache, nausea and dizziness.
Studies of workers exposed to high levels of sulfur dioxide have found increased risk for
lung, stomach and brain cancer
Exposure to increased levels from outdoor air pollution during
pregnancy is associated with an increased risk for
low birth
weight and premature birth.
Long term exposure may
decrease fertility in males and females.
Third: Sulphur effect on environment
ACID RAINS effects on Forests
ACID RAINS effects on our Cities
What Policy Makers are asking to Maritime
EU 01
What Policy Makers are asking to other sectors
Currently, jet fuel has a specification maximum of 3,000 ppm for
However, jet fuel in the market has a lower sulphur content.
Worldwide surveys conducted over the years found that annual
weighted average jet fuel sulphur content ranged from 321-800 ppm.
Hydrodesulphurization, which could be applied to remove the fuel
sulphur, is a common process in petroleum refineries, and low sulphur
diesel fuel is already widely used internationally.
Low sulphur jet fuel has a sulphur content less than 15 ppm.
What Policy Makers are asking to other sectors
Land Based Transport
“SECA” for Land Based Transport
The strictest limit for shipping fuel, as of 2015 applicable in the Sulfur Emission
Control Areas will still be 0,1%.
The permissible sulfur content of diesel fuel for land based transport is limited to
10 ppm (i.e. 0,001%).
The permissible sulfur content of aviation fuel is limited to 600 ppm (i.e. 0,06%)
with a program for further reduction to 15 ppm (i.e. 0,0015%).
That means ships will still be allowed to emit 100 times (!) more sulfur per fuel
unit respect to land based transport.
That means ships will still be allowed to emit still 2 times (!) more sulfur per fuel
unit respect to air based transport in the short run and nearly 100 times more in
the long term perspective.
Technical Issues
Low sulphur fuels
Properties “made worse”
Properties “improved”
Aromatics & Naphthalenes
Aromatics & Naphthalenes
(for effect on aged fuel system elastomers)
(for combustion properties)
Specific Energy
Hydrogen content
Copper Corrosion
Water Separation
Thermal stability (for
continuous operation)
Technical Issues
Main problems identified on components like (but not
Cylinder Oils
Technical Issues
In California, where fuel switching regulations have been
in force since 1 July 2009, there were 15 reported
casualty investigations attributed to fuel switching in
the three months following implementation.
The San Francisco Bar Pilots now say they have seen an
incident every 1 – 3 days, involving engine failures, start
failure whilst at berth and/or changes in speed which
effect maneuverability.
Technical Issues:
Boilers - Usage
Boilers are used on ships either for propulsion or as auxiliary
Boilers for propulsion are used in combination with steam
turbines but uncommon.
Boilers are used for propulsion in ships that transport LNG.
Cargo boil off during transport is used as fuel for the ship.
For thermal efficiency, these boilers operate at high pressure of
about 60 bar.
Boil-off gas (BOG) is used for propulsion in combination with a
liquid fuel.
Technical Issues:
Boilers - Problems
Boilers that are constructed for the use of Heavy Fuel Oil
(HFO) can in general not be used with Marine Gas Oil
(MGO) without modifications.
A switch from HFO to
MGO in a boiler that is
designed for HFO use
could lead to operational
problems with potential
flame failure and an
increased risk of a boiler
Technical Issues:
Boilers - Solutions
Reports state that boiler explosions are due to defects or improper
(Flame out for some reason and a high pressure of fuel gas is built up in the burner and
the control system is malfunctioning or disconnected).
Proper procedures, training, and maintenance are essential for
vessels to safely switch between heavy/intermediate fuel oils
and marine distillates.
Modification in burner management and associated control
systems are needed (as flame failure detection).
See also IMO subcommittee on bulk liquids (2007)
Technical Issues:
Piping - Problems
The existing piping used to transport heated HFO from the pump to the
boiler may not be suitable to transport MGO:
(1) MGO needs to be delivered at ambient temperature (storage tank
temperature – 40°) while HFO is delivered at 150°;
(2) exists a concern that MGO flowing through hot piping may vaporize
creating vapor locks and causing irregular fuel flow towards the burner
resulting in flame extinction. The lighter the fuel, the easier the
evaporation and the larger the risk for an air/fuel mix which is potentially
Therefore, MGO is not to be delivered through heated pipes to the burner.
Technical Issues:
Piping - Solutions
In normal ship installations, "heat tracing" of pipes (by steam or electric
heating) can be turned on or off. In this kind of installation, proper
operation may be sufficient to avoid the risk of an explosion.
In many cases, the operation of fuel switching is automatically handled by
the ships' hardware and software.
There are concerns that the crew on many ships may not be familiar with
how to handle safely these situations. Proper instructions should be given.
Consideration should be given to dedicated MGO delivery piping and
The boilers do normally run on MGO during start up; however, at this point the system has not yet been heated. After
the boiler pressure is up, the pipes can be emptied of MGO and then heated and used for HFO. MGO is thus not
introduced to the boiler through heated pipes at this stage.
Technical Issues:
Pumps - Problems
There is an increased risk of wear and pump breakdown if the oil has a higher
viscosity and lower lubricity than what the pump is designed for.
Extremely low sulphur content and consequent low viscosity levels have a strong
impact on fuel injection and pump/valve lubrication
There may be increased smoke emissions since the amount of fuel injected in
the burner is set for HFO with a higher density and lower calorific value than
When two different fuels are mixed there is a risk of incompatibility, which may
cause clogging of fuel filters and separator, sticking of fuel injection pumps and
considerable pump deterioration
Technical Issues:
Pumps - Solutions
Screw pumps must be modified;
Specially treated materials;
Fuel pumps and valves may need to be replaced due
to the different viscosity of the fuels;
Pumps must be capable of handling low viscosity
fuels while retaining the required pressures and
Technical Issues:
Cylinder Oils - Problems
Cylinder oil used in large slow speed diesel engines is highly
alkaline to counteract the acidic conditions produced when
burning the more normal high sulphur fuel oil.
The affect of using low sulphur fuel could lead to the situation
where excess alkalinity occurs.
Excess alkalinity could be as corrosive as excess acidity.
Additives package not necessary when low sulphur fuels are
used. Risk of metal to metal contact in the piston (rings/liner)
and rapid wear due to additives deposit.
Technical Issues:
Cylinder Oils - Solutions
The grade of cylinder oil should therefore
be matched to the sulphur content of the
fuel and both Owners and Engine
Manufacturers may have to consider the
possibility of dual cylinder oil systems.
Technical Issues:
Storage- Problems
The problem of different grades of fuel could mean segregated storage
tanks but it also raises the possibility of dual pumping systems etc.
At the moment most ships do not have enough individual tanks to be
able to keep some tanks just for low sulphur fuel for those few
occasions when a vessel will be in a SECA.
Charterers are also raising problems because if a vessel keeps certain
tanks just for low sulphur fuel, they are not available to the Charterer to
use for bunkering in low cost ports.
Also if these segregated tanks are relatively small, they may not have
the capacity to take the minimum quantity of a grade imposed at some
ports with financial implications for Charterers.
Technical Issues:
Storage- Solutions
One way round the problem of dual
pumping systems would be to change
over to low sulphur fuel early enough so
that the transfer system and daily use
tanks are flushed through before the
vessel enters a SECA but this would have
to be planned well in advance of entering
Considerable justified uncertainty
as to how, and to what extent, the
Directive would be enforced after
The Recommendation directs
the 1 January deadline.
Member States to enforce the
Directive fully and completely as
from 1 January 2010. However,
indicates to assess the appropriate
The position beginning to
penalty to be applied to nonemerge is that Member States
complying vessels.
are starting to enforce the
reluctantly, but in some cases
with gusto.
Some Italian ports have taken a
harder line and Trieste, for
example, will issue non-complaint
In early April 2010, the United vessels burning higher sulphur
Kingdom announced that it would fuels with fines of between
be fully enforcing the Directive €15,000 and €150,000.
from 20 April 2010. From this
date, ships at berth in U.K. ports
are not permitted to use bunker
In contrast, authorities in France
fuel exceeding the 0.1% limit.
and Germany have confirmed that
they will be applying the Directive,
but do not appear to have offered
a clear response or guidelines
Technical problems do exists
Technical Solutions do exsist
Investments are necessary
Investments, such as:
•Implementing fuel saving measures;
•Installing exhaust cleaning equipment ;
•Switching to LNG as fuel.
can decrease the fuel cost burden to a fraction by investing new ships
or up-grading existing ones.
Policy Makers should take appropriate action to facilitate the
application of cleaner technologies .
+++ Thank you for your attention +++
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