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1
TRANSPHORM deliverable
Report from analysis of traffic activity in selected cities
D1.2.1
Lead beneficiary: IVL
Person months: 12
Nature: REPORT (R)
Dissemination level: PUBLIC (PU)
Delivery date from ANNEX I: MONTH 32
Notes:
Table of contents
Deliverable overview.............................................................................. 1
Copy of deliverable………………………………………………………………………………. 2
TRANSPHORM
Transport related Air Pollution and Health impacts –
Integrated Methodologies for Assessing Particulate Matter
Collaborative Project, Large-scale Integrating Project
SEVENTH FRAMEWORK PROGRAMME
ENV.2009.1.2.2.1 Transport related air pollution and health impacts
Deliverable D1.2.1, type R
Report on shipping emission factors
Due date of deliverable: project month 12
Actual submission date: project month 13
Start date of project: 1 January 2010 Duration: 48 months
Organisation name of lead contractor for this deliverable: IVL
Scientist responsible for this deliverable: Jana Moldanová
Revision: [1]
D1.2.1 TRANSPHORM Deliverable
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Contents
Report on shipping emission factors 3
Introduction 3
International legislation on emissions from shipping 6
Abatement techniques for reduction of air pollution 9
Emission factors for SO2 and CO2 10
Emission factors for VOC and CO 10
Emission factors for NOX 11
Emissions factors for PM mass 13
Emissions factors for PM number concentration 17
Emissions factors for PAH and benzo(a)pyrene 18
Conclusions 20
References 21
Deliverable TRANSPHORM D1.2.1
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Report on shipping emission factors
Jana Moldanová1, Erik Fridell
1, Andreas Petzold
2, Jukka-Pekka Jalkanen
3
1 IVL, Swedish Environmental Research Institute, Box 5302, 40014 Gothenburg, Sweden
2 Deutche Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, 82234 Wess-
ling, Germany 3 Finish Meteorological Institute, P.O. Box 503, 00101 Helsinki, Finland
Introduction
The main focus of this report is on emissions of particulate matter (PM) expressed as mass, number
size-distribution as well as some characteristics of the particle emissions such as black carbon, or-
ganic carbon and PAH. However, emission factors for a number of other compounds will be de-
scribed briefly. In the following text the emission factors reported in a few papers with compiled
data will be used to present suggested emission factors.
Emissions from a fleet of ships are usually calculated by means of quantifying the fuel consump-
tion by power production first and then multiplying the consumption by emission factors. Some
inventories use the bunker sales statistics as a direct estimate of the fuel consumption together with
an assumption of a distribution of ship and engines types. Others, including the bottom-up invento-
ries, estimate the power production, and thus the fuel consumption of individual ships, from fleet
movement statistics. Emission factors (EF) used are then related either to the generated power EFp
(g(species)/kWh) or to the fuel consumed EFf (g(species)/kg(fuel)), where the first one multiplied by the
specific fuel consumption (SFC, unit g(fuel)/kWh) is equal to the second one.
Emissions from a marine engine will depend on the type of fuel used as well as on characteristics
of the engine. The most important fuel parameters are if the fuel is heavy fuel oil (residual fuel,
HFO) or marine distillates (marine gasoil, MGO or marine diesel, MDO) and the sulphur content
(FSC). The emissions likely depend on the viscosity and the aromatics content of the fuel but there
is not sufficient data to link emission factors to these parameters. There are some other fuels that are
much more uncommon such as biodiesel, coal and natural gas.
Emissions have been found to vary significantly between engines. Probably the maintenance and
age of the engine are important for certain emission factors. For calculating emissions one usually
considers the engine power, the engine speed and the emissions standard. The latter applies to ni-
trogen oxides only. However, one can suspect that the emissions standard also will influence the
emissions of, e.g. particles and hydrocarbons, although there is, for most cases, not enough data
available to draw conclusions about this.
The engines on ships are usually one or several main engines, used for propulsions and a number
of auxiliary engines, used for propulsion, electricity generation, pumps etc. The main engine is of-
ten equipped with a shaft generator that produces electricity when the main engine is in operation.
In addition there are usually a number of boilers for hot water production fuel heating etc. Dominat-
ing sources of emissions at open sea are the main engines. At berth these are usually turned off
while the auxiliary engines still are being used. For those engines on ships operating with a power
plant principle, main engines are used for electricity generation and electrical motors are used for
propulsion. In these cases main engines are used both for propulsion and all additional equipment
power needs thus obviating the need for separate auxiliary engines. Here, main engines are run also
during harbour visits.
D1.2.1 TRANSPHORM Deliverable
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The engines are usually divided by engine speed into slow speed (60 – 300 rpm), medium speed
(300 – 1000 rpm) and high speed (1000 – 3000 rpm). Most modern larger merchant ships use slow
speed, two stroke engines or medium speed, four stroke engines. Some smaller vessels may use
high speed, four stroke diesel engines. The specific fuel consumption (SFC), expressed as mass of
fuel per unit of work by the engine (g/kWh), depend on the engine type and on the type of fuel used.
Typical values can be found in Table 1. Note that the SFC varies between different engines and will
typically be lower for larger engines than for smaller.
The fuel consumptions in Table 1 are for typical design speeds which usually correspond to an
engine load of 80-85% of the maximum engine power. If the engine is used at lower or higher loads
the specific fuel consumption is typically higher. Figure 1a shows SFC variation with changing en-
gine load under typical marine engine operation regime for a Wärtsilä 45 engine and SFC variation
used in the STEAM model (Jalkanen et al., 2009, Jalkanen et al., 2011). It can be seen that the SFC
will increase sharply at low loads. Figure 1b shows an example of how the SFC can vary with en-
gine load at different engine speeds.
Table 1. Specific fuel consumption for marine engines (Cooper and Gustafsson, 2005)
Engine type Fuel type SFC (g/kWh)
Slow speed Residual oil 195
Marine distillates 185
Medium speed Residual oil 215
Marine distillates 205
High speed Residual oil 215
Marine distillates 205
Emissions of some species like SO2, CO2 and metals are directly proportional to the SFC and fuel composition, regardless the type of engine or its operation regime (abatement techniques not accounted). Others, like NOX, VOC, CO and PM are dependent on combustion regime and thus on type of engine, its power setting and on physical properties of the fuel.
Deliverable TRANSPHORM D1.2.1
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a)
b)
Figure 1. Specific fuel oil consumption (SFC) change as a function of engine load. a - SFC as a function of engine
load under typical marine engine operation regime for a Wärtsilä 45 engine and SFC variation used in the
STEAM model (Jalkanen et al., 2009, Jalkanen et al., 2011). b – SFC change at variable engine speed from
Wärtsilä 45 project guide (2007). The iso-lines show the increase in fuel consumption in g/kWh relative to the
stated SFC at design speed.
SFC
(g/
kWh
)
Engine load
Wärtsilä46
D1.2.1 TRANSPHORM Deliverable
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International legislation on emissions from shipping
Legislation is in force to control the emissions from shipping through Annex VI of the Marine Pol-
lution Convention (MARPOL) that was adopted in 1997 by the Marine Environmental Protection
Committee (MEPC) of the International Maritime Organisation (IMO) and came into force in May
2005 (IMO, 2006). Annex VI with its amendment from October 2008 put limits on emissions of
SO2 and NOX globally and contains provisions allowing establishment of Emission Control Areas
(ECA) with more stringent reductions of fuel–sulphur content and of emissions of NOX, or both
(IMO, 2009). Emission Control Areas for PM are mentioned in Annex VI as well, however no regu-
lation for PM as such is given and the PM reduction is expected to come from the reduction of fuel-
sulphur.
Globally the average sulphur content in fuel is today around 2.7% while the IMO limit value is
4.5% which will be reduced to 3.5% after January 1, 2012. From the 1st of January 2020
1 the fuel
sulphur content will be below 0.5% which will effectively reduce the emissions of SO2 and of sul-
phate particles (Figure 2).
Figure 2. The maximum fuel sulphur content (FS, in mass %) for marine fuels allowed globally and in Emission
Control Areas (ECAs) given by IMO (years when different ECAs enter in force are shown) and the current av-
erage FS of HFO and MDO used by the global fleet (average fuel composition from Endresen et al., 2005)
For emissions of NOX all ships newly built or with installed engine manufactured after year 2000
and prior to 1st of January 2011 must meet the Tier I emission standard and after 1
st of January 2011
the Tier II standard (Figure 3). In addition, after the 1st of January 2016 the Tier III standard must
be met for ships operating in NOX-emission protection areas. The revised Annex VI expanded the
Tier I rules on engines built between 1st of January 1990 and 1
st of January 2000 for ships equipped
with engine with a power output of more than 5,000 kW and cylinder displacement at or above 90
litres provided that an approved and certified method for reduction of NOX emissions exists for the
engine.
1 This regulation may be postponed to 2025 if there is risk of fuel shortage
0 %
1 %
2 %
3 %
4 %
5 %
2005 2010 2015 2020
F S
IMO global limit
ECA limit
Global average HFO
Global average MDO
Baltic Sea ECA
North Sea & English Ch. ECA
North America’s coasts ECA
Deliverable TRANSPHORM D1.2.1
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Figure 3. The maximum emission factors for NOX (g/kWh) for marine diesel engines given by IMO
In Europe establishment of ECA for SOX in the Baltic Sea entered into force in May 2005, in the
North Sea and English Channel in November 2006 and both ECAs entered in effect 1 year later. In
these areas the allowed sulphur content has been reduced from the initial limit value of 1.5% to 1%
after 1st of July 2010 and will be further reduced to 0.1% 1
st of January 2015. In North America‟s
coastal waters the ECA for SOX and NOX will enter into effect 1st of August 2012 (see Figure 2).
Extension of the European ECAs to NOX emissions is under the discussion. In October 2010 pro-
posal of ECA for waters around Puerto Rico and the Virgin Islands was approved on the 61st ses-
sion of the Marine Environmental Protection Committee (MEPC 61). Establishment of this ECA
will enter into force in 2012 (www.imo.org).
Considering the long lifetime of ship engines, the NOX legislation will impact the NOX emis-
sions only with a large delay. Further, the expected increase in the volume of ship movements will
compensate for the environmental benefits of these measures and will lead to a continued growth in
ship emissions. So far the IMO does not specifically regulate particle emissions and there are stud-
ies showing that even with low-sulphur marine diesel, the PM emissions will still be significant
(Winnes and Fridell, 2009).
The rules governing the maximum permitted content of sulphur in fuels used for international
shipping as determined by Annex VI of the MARPOL73/78 have been transposed into EU law and
complemented by directive 2005/33/EC on the sulphur content of certain liquid fuels which in Au-
gust 2005 amended directive 1999/32/EC. Directives 1999/32/EC and 2005/33/EC (EC, 1999; EC,
2005) provide fuel sulphur content regulations for vessels operating in EU territorial seas as pre-
scribed in Annex VI (not its year-2008 amendment). In addition all passenger vessels on regular
services in EU territorial seas, also those operating outside the ECAs, must from 11 August 2006
comply with the 1.5% sulphur limit. These directives provide also sulphur limits for marine gas oils
(MGO) and marine diesel oils (MDO) sold in the EU member states. Until 10 August 2006 applied
the 0.2% sulphur limit to all marine distillates used in EU territory excluding ships in the territory
of Greece, the French DOM-TOM, Madeira, the Azores and the Canary Islands. Between August
2006 and December 2007, the 0.2% sulphur limit for lower grade marine diesel oils was dropped,
and a less stringent limit of 1.5% sulphur was introduced to allow use of the marine diesel oils in
order to comply with the SOX Emission Control Areas, in case supplies of 1.5% S heavy fuel oil
were insufficient. The exemption for Greece and the outermost regions continued to apply. Between
January 2008 and December 2009 a more stringent 0.1% sulphur limit applied to high grade marine
0
5
10
15
20
0 500 1000 1500 2000 2500
EF N
Ox
(g/k
Wh
)
Engine speed (rpm)
TIER I
TIER II
TIER III
D1.2.1 TRANSPHORM Deliverable
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gas oils used in EU territory while the 1.5% sulphur limit for the low grade marine gas and diesel
oils continued to apply. The exemption for Greece and the outermost regions continued to ap-
of marine gas oils in EU territory (described above) were deleted. Instead a 0.1% sulphur limit was
introduced for all marine gas oils placed on the market in EU Member States‟ territory. At the same
time a 0.1% sulphur limit started to apply to all types of marine fuel used by ships at berth in EU
ports and by inland waterway vessels. This applies to any use of the fuel e.g. in auxiliary engines,
main engines, boilers. This legislation goes beyond IMO‟s Annex VI. There are following exemp-
tions from this 0.1% limit: for ships which spend according to published timetables less than 2
hours at berth, for hybrid sea-river vessels while they are at sea, and for ships at berth which switch
off all engines and use shore-side electricity. The outermost EU regions continue to be exempt from
this provision, but Greece does not, apart from a 2-year derogation for 16 named Greek vessels until
2012. From July 1st 2010 the more stringent 1% FSC limit of IMO applies in European ECAs while
EC is preparing legislation that will transpose the 2008-amendment of Annex VI into EU law (to be
published in June 2011). Figure 4 shows development of the limits of the sulphur content of marine
fuels in EU.
Figure 4. The maximum fuel sulphur content (FS, in mass %) for marine fuels allowed in EU territorial waters
and EU inland waterways given by Directives 1999/32 and 2005/33/EC.
0.0%
0.5%
1.0%
1.5%
2.0%
2005 2007 2009 2011 2013 2015
F S
Marine fuels used in EU ECAs (as established)
Marine fuels used by passenger vessels in all territorial seas
Marine fuels used in EU ports by ships at berts& in inland waters
MGO sold in EU
lower grade MDO&MGO (transient)
MDO sold in EU
Deliverable TRANSPHORM D1.2.1
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Abatement techniques for reduction of air pollution
Emission factors need to take into account effects of abatement techniques. Some reductions of emission factors are summarized in Table 2. Most abatement techniques focus on the emissions of NOX. The most effective technique is selective catalytic reduction (SCR) where NOX react with an added reducing agent (normally urea) over a catalyst to produce nitrogen gas. The process is very efficient and reduction factors of 95% can be reached. There is however a certain minimum exhaust temperature needed for the reaction to take place. Many SCR installations are equipped with an oxidation catalyst in order to minimise the ammonia slip. This will also lead to the oxidation of CO and hydrocarbons thus reducing those emissions. Further, an SCR will also influence the PM emis-sions although the details are not quite clear. Other techniques for NOX reduction includes exhaust gas recirculation (EGR), engine modifications and different techniques to introduce water into the engine (humid air motor, HAM, direct water injection, DWI, emulsifier).
Scrubber techniques can be used to reduce the emissions of sulphur oxides to the atmosphere. The scrubbers can operate either with seawater or with freshwater under the addition of an alkaline compound. The scrubbers will trap the SOX as sulphates in the water. The efficiency will depend on, among other things, the alkalinity of the water and the volumes. Scrubbers will also capture particles but the efficiency varies between different reports.
Table 2. The various abatement techniques and their evaluated emission reduction efficiencies.
Abatement technique EFNOx EFSOx EFCO EFVOC EFPM EFNH3
Low NOX engine technologies1 −20% ±0
* ±0
† ±0
†
Exhaust gas recirculation1 −30 - −40%
Direct Water Injection1 −50 - −60% ±0 ±0 ±0
Humid Air Motor1 −70 - −85% ±0 ±0 ±0
Selective Catalytic Reduction1 −91% ±0 ±0 ±0 +0.1 g/kWh
SCR + oxidation catalyst2 −90% −70% −80%
Sea Water Scrubber3 ±0 −95% ±0-80%
‡
Fuel Emulsifier3 −10%
Wetpac3 −50%
* Some increase possible
† Unconfirmed up to 50 % reduction
‡ Value from Jalkanen et al. (2011). According to Corbett (2010) reductions range from -98% to -45%, largest fractions
of PM are reduced more effectively than the small ones. 1 Lövblad and Fridell, 2006
2 Cooper and Gustafsson, 2004
3 Jalkanen et al., 2009
D1.2.1 TRANSPHORM Deliverable
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Emission factors for SO2 and CO2
The emission of SO2 is proportional to the fuel consumption and the sulphur content in the fuel.
This is because virtually all the sulphur in the fuel will be oxidised into SO2 in the engine. The
emission factor expressed as mass of SO2 emitted per mass of fuel consumed is therefore
EFSO2 (g/kg fuel) = fS(%) * 20, (E 1)
where fS is the mass fraction of S in the fuel (in weight per cent) and factor 20 (19.97) comes from
recalculation of the molar weight from S to SO2 and from % to g/kg. To express the emission in
mass per engine work the specific fuel consumption must be used. In a more detailed analysis one
should consider that some sulphur is oxidised further into SO3 and may form sulphate particles.
This is typically on the order of 1-5 per cent of the S-content in the fuel, depending on the engine
load (Petzold et al., 2010).
In a corresponding way the emissions of CO2 will be dependent on the carbon content in the fuel
and the fuel consumption. This then neglect the small fraction of the carbon that will be emitted as
carbon monoxide, organic compounds and soot. The sum of these will typically be two to three or-
ders of magnitude lower than the CO2-emissions. The carbon content in marine fuels can vary
somewhat but is normally around 87%. Table 3 shows the emission factors for SO2 and CO2 for
different engine types expressed in mass of emission per engine work and mass of emission per
mass of fuel consumed.
Table 3 Emission factors for CO2 and SO2 from Cooper and Gustafsson (2004)
Engine type Fuel type FSC EFCO2
(g/kWh)
EFCO2
(g/kgfuel)
EFSO2
(g/kWh)
EFSO2
(g/kgfuel)
Slow speed Residual oil 2.7% 620 3 179 10.5 54.0
Residual oil 1% 620 3 179 3.90 20.0
Marine distillates 0.5% 588 3 179 1.85 10.0
Marine gas oil 0.1% 588 3 179 0.37 2.0
Medium Residual oil 2.7% 683 3 179 10.6 54.0
speed Residual oil 1% 683 3 179 4.30 20.0
Marine distillates 0.5% 652 3 179 2.05 10.0
Marine gas oil 0.1% 652 3 179 0.41 2.0
High speed Residual oil 2.7% 683 3 179 10.6 54.0
Residual oil 1% 683 3 179 4.30 20.0
Marine distillates 0.5% 652 3 179 2.05 10.0
Marine gas oil 0.1% 652 3 179 0.41 2.0
Emission factors for VOC and CO
The emissions of hydrocarbons and carbon monoxide represent incomplete combustion of the fuel.
These emissions from marine diesel engines are typically small due to the lean burning conditions
and stable engine loads, but sharp increases may occur during rapid load changes of engines (accel-
eration/deceleration phases) because of incomplete combustion of fuel. Typical emission factors can
be found in Table 4. Note that the emission of CO and HC will increase at lower load (manoeuvring
in Table 4). The details in the emissions at lower loads will depend on the operation and on the in-
dividual engine. Sarvi et al (2008) investigated the effect of engine load on emission factors of CO
and HC on a four-stroke MSD engine using HFO (Figure 5).
Deliverable TRANSPHORM D1.2.1
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Figure 5. Effect of engine load on emission factors (in g/kWh) for CO and HC. The engine is a four-stroke MSD
in propulsion mode using HFO (from Sarvi et al., 2008, their Figs 4 and 5).
Table 4. Emission factors for CO (EFCO) and HC (EFHC) from Cooper and Gustafsson (2004).
Engine type Fuel type Operational
mode
EFCO
(g/kWh)
EFCO
(g/kgfuel)
EFHC
(g/kWh)
EFHC
(g/kgfuel)
Slow speed Residual oil At sea 0.5 2.5 0.3 1.6
Manoeuvring 1.0 4.6 0.6 2.8
Marine distillates At sea 0.5 2.7 0.3 1.5
Manoeuvring 1.0 4.9 0.6 2.9
Medium speed Residual oil At sea 1.1 5.1 0.2 0.9
Manoeuvring 2.2 9.2 0.4 1.7
Marine distillates At sea 1.1 5.3 0.2 1.0
Manoeuvring 2.2 9.7 0.4 1.8
High speed Residual oil At sea 1.1 5.1 0.2 0.9
Manoeuvring 2.2 9.3 0.4 1.7
Marine distillates At sea 1.1 5.4 0.2 1.0
Manoeuvring 2.2 9.8 0.4 1.8
Emission factors for NOX
The larger part (~90%) of the nitrogen oxides emitted from marine engines is formed from nitrogen
in the air at the high temperatures prevailing in the combustion zones in the cylinders. The emis-
sions of nitrogen oxides is as mentioned earlier regulated for engines manufactured after the year
2000 and for engines with a power output of more than 5,000 kW and cylinder displacement at or
above 90 litres after 1990. The emission standards define the maximum allowed NOx emission fac-
tor (in g/kWh) determined by the year of installation of the ship engine and by its rated speed n.
This NOx emission factor is a weighted emission factor for a certain driving cycle at standard en-
gine inlet air humidity (10.71 g/kg) and temperature (25ºC). The driving cycle depends on type of
0
0.5
1
1.5
2
2.5
3
25 50 75 100
EF (
g/k
Wh
)
Engine load, % of max
CO
HC x 10
D1.2.1 TRANSPHORM Deliverable
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engine (cycles C1 for variable-speed, variable-load auxiliary engine, D2 for constant-speed auxilia-
ry engine, E2 for “Constant-speed main propulsion” application including diesel-electric drive and
all controllable-pitch propeller installations, E3 for propeller-law-operated main and auxiliary en-
gines) and the measured emission factor is corrected to the standard conditions. Determination of
the NOx emission factors is in detail described in the NOx Technical Code (Annex 14 i.e. revised
Annex VI of MARPOL from 2008, for Tier I is until 2011 possible to use Annex VI from 1997).
Emission factors in Tier I standard represents engine standard of year 2000, for older vessels an
engine upgrade may be needed but that is obligatory only provided that an approved and certified
method for reduction of NOX emissions exists. Tier II standard represents c.a. 20% emission reduc-
tion from Tier I and is expected to be met by internal engine combustion optimization measures.
The parameters examined by engine manufacturers include fuel injection timing, pressure, and rate
(rate shaping), fuel nozzle flow area, exhaust valve timing, and cylinder compression volume. Tier
III standard represents c.a. 80% reduction and requires dedicated NOx emission control technolo-
gies such as various forms of water induction into the combustion process (with fuel, scavenging
air, or in-cylinder), exhaust gas recirculation, or selective catalytic reduction. Typical emission fac-
tors for the different Tiers and engines speeds can be found in Table 5.
Table 5. Emission factors for NOX from Cooper and Gustafsson (2004) (no Tier) and IMO regulations. The emis-
sion factors in g/kgfuel assume that the SFC will not change between the Tiers.
Engine type Fuel type Emission
class
EFNOx
(g/kWh)
EFNOx
(g/kgfuel)
Slow speed Residual oil No Tier 18.1 87.4
Tier 1 17.0 82.1
Tier 2 14.4 69.5
Tier 3 3.4 16.4
Marine distillates No Tier 17.0 91.6
Tier 1 17.0 91.6
Tier 2 14.4 77.6
Tier 3 3.4 18.3
Medium speed Residual oil No Tier 14.0 61.7
Tier 1* 11.3 49.8
Tier 2† 8.98 39.6
Tier 3‡ 2.26 10.0
Marine distillates No Tier 13.0 63.2
Tier 1* 11.3 54.9
Tier 2† 8.98 43.7
Tier 3‡ 2.26 11.0
High speed Residual oil No Tier 12.7 58.9
Tier 1 9.8 45.5
Tier 2 7.7 35.7
Tier 3 1.96 9.1
Marine distillates No Tier 12.0 58.3
Tier 1 9.8 47.6
Tier 2 7.7 37.4
Tier 3 1.96 9.5 * EF for engine speed n = 1000 to 2000 rpm, EF = 45 · n
(-0.2) in Tier I.
† EF for engine speed n = 1000 to 2000 rpm, EF = 44 · n
(-0.23) in Tier II.
‡ EF for engine speed n = 1000 to 2000 rpm, EF = 9 · n
(-0.2) in Tier III.
Deliverable TRANSPHORM D1.2.1
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Emissions factors for PM mass
Particles emitted by marine engines consist of a volatile and non-volatile fraction. Volatiles are mainly sulphate with associated water and organic compounds. Non-volatiles consist of elemental carbon (soot, char) and of ash and mineral compounds containing Ca, V, Ni and other elements. Because of the high content of condensable matter in the exhaust the methodology of sampling im-pacts the PM mass found. Sampling directly in the hot exhaust captures to a large extend only the non-volatile part of PM while sampling in the diluted and cooled exhaust captures also some of the volatiles. The amount, however, depends on the dilution and temperature program of the sampling. Figure 6 shows the difference between PM sampled in the hot and diluted exhaust from a slow-speed diesel engine running on HFO with 1.9% sulphur.
Figure 6 Composition of PM (as mg/m3 exhaust gas) collected on filters in the diluted and hot exhaust gas (Mol-
danová et al., 2009).
Emissions of PM varies with fuel type, fuel sulphur content and engine operation mode. Table 6
shows EFPM for cruise conditions published by Cooper and Gustafsson (2004) for different marine
engines for HFO and MDO fuels together with EFPM from the Lloyds emission database (European
Commission, 2002). These emission factors are based on larger number of measurements (c.a. 45
measurements at IVL database and 25 in Lloyd‟s database). The mean FSC in Cooper and Gus-
tafsson (2004) was 2.3% and in EC (2002) 2.7%. The PM measurements reviewed in these reports
were performed using the partial dilution equipment, i.e. corresponding to the PM in „diluted‟ ex-
haust in Figure 6.
0
50
100
150
200
dilluted hot
mg/m
3
unidentified
sulph. assoc. water
sulphate
OC
EC
ash
D1.2.1 TRANSPHORM Deliverable
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Table 6. Emission factors for PM mass (EFPM) for cruise and manoeuvring conditions from Cooper and Gus-
tafsson (2004) for different marine engines for residual oil (RO) and marine distillates (MD). The mean FSC is
2.3 wt.% for RO and 0.4 wt.% for MDO. EFPM for cruise conditions from the Lloyds emission database (Euro-
pean Commission, 2002) for the global fleet, these EFPM are weighted for fuels used by the engine category. The
global FSC in this study is 2.7 wt.%.
Cooper & Gustafsson (2004) EC (2002)
Engine type Fuel type EFPM at sea EFPM manoeuvring EFPM at sea
g/kWh g/kgfuel g/kWh g/kgfuel g/kg fuel
SSD MD 0.2 1.08 0.4 1.97 7.6*
SSD RO 1.3 6.67 2.6 12.12
MSD MD 0.2 0.98 0.4 1.77 1.2*
MSD RO 0.5 2.33 1.0 4.23
HSD MD 0.2 0.98 0.4 1.77
HSD RO 0.5 2.33 1.0 4.23 * Mixture of MD and RO
When more recent data from individual engines are added, one can see a span of EFPM for en-gines using RO between 1 and 13 g/kg fuel with the mean around 7, and for engines using MD be-tween 0.2 and 1 g/kg fuel. Figure 7 shows a plot of the available data on EFPM at cruise conditions (engine load 75-90%) against the fuel-sulphur content (FSC). We can see a clear linear relation be-tween emission factor for PM and the FSC for data measured on engines using RO. Emission factor for MSD engines from Cooper and Gustafsson (2004) are lower comparing to other data, however there are only few more individual measurements for this engine and fuel category available. The Lloyds EF for SSD engines are included (EC, 2002) assuming FSC 2.7% which is Lloyd‟s estimate of the global mean FSC for RO.
Figure 7. Emission factors for particle mass EFPM as a function of FSC. EFPM for RO is plotted in blue, data for
MSD engines are with white cross, filled blue are for SSD. EFPM for MD is plotted in green, all for MSD engines.
The blue line is linear regression for the data measured on engines using residual oil (RO) (EFPM = 4.43 x FSC –
3.29, R2 = 0.63).
0
2
4
6
8
10
12
14
0 1 2 3 4
EFP
M [
g/kg
fu
el]
FSC [wt.%]
RO
RO MSD
MD
EC (2002)
Cooper (2004)
Cooper (2004)
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PM mass emission factors change with the engine load. In the stack typically between 1 and 5%
of sulphur is oxidized to SO3 (Moldanová et al., 2009; Petzold et al., 2010) and contributes to the
exhaust PM. Petzold et al. (2010) showed a positive correlation between the SO2 in-stack oxidation
and the engine load for engines using HFO with similar fuel sulphur content (between 2 – 2.5%)
(Figure 8a). While EF for sulphate is positively correlated to the engine power, i.e. contributes most
to the PM emissions at high engine loads, emissions of black or elemental carbon and of organic
carbon are higher at low engine loads and have their minima at loads around 50% and increases
somewhat at cruise conditions (Figure 8b, Petzold et al., 2010,). The resulting dependence of EFPM
on engine load thus varies with fuel sulphur content and potentially also with fuel type. One should
also remember that the fuel consumption of course also varies with the engine load making the
emissions (in g/hour) higher at cruising that at low loads.
In the STEAM2 model Jalkanen et al. (2011) use EFPM (emission factor for total particulate mat-
ter mass) and emission factors for 5 different PM components: EC, OC, sulphate, ash and the sul-
phate-associated water as a function of engine load and the FSC. The FSC dependence is built on
data from the 2nd IMO GHG study (IMO, 2009) and the dependence on engine load on data from
Agrawal et al. (2008a), Petzold et al. (2008) and Moldanova et al. (2009). Table 7 and Table 8 show
emission factors from STEAM2 for a span of FSC and engine loads.
a)
b)
Figure 8. a - Efficiency for converting fuel sulphur to particulate-matter sulphate at various engine loads and for
fuels with different sulphur contents given in wt-%; the dashed line represents a linear relationship between part
of sulphur in exhaust converted to sulphate and engine load. (Ref (1): Kasper et al., 2007; Ref (2): Agrawal et al.,
2008a; Ref (3): Agrawal et al., 2008b; Ref (4): Moldanová et al., 2009; other data: Petzold et al., 2010) (from
Petzold et al., 2010, their Fig. 4). b - Mass emission factor for carbon-containing compounds, sulphate and PM in
the raw exhaust gas, FSC 2.40wt-% (EC - elemental carbon, OM – organic matter, both analysed by multi-step
combustion method) (from Petzold et al., data in their Table 1).
0 20 40 60 80 100 1200.0
1.0
2.0
3.0
4.0
5.0
6.0
test, 2.40 wt-%
serial, 2.32 wt-%
Ref (1), 0.16 wt-%
Ref (2), 2.05 wt-%
Ref (3), 2.85 wt-%
Ref (4), 1.95 wt-%
Kurok, unpublished
su
lfu
r co
nve
rsio
n ,
%
engine load , % of max
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Table 7. Total PM2.5 emission factors (g/kWh) at selected engine loads and fuel sulphur content (wt-%)
Load 0.1% S 1.0% S 1.5% S 2.7% S 3.5% S
20% 0.41 0.99 1.31 2.08 2.60
40% 0.38 0.91 1.21 1.92 2.40
60% 0.36 0.87 1.15 1.83 2.28
80% 0.35 0.86 1.14 1.80 2.25
100% 0.36 0.88 1.16 1.84 2.30
Table 8. The emission factors of PM2.5 subcomponents (g/kWh) as a function of engine load. The fuel sulphur
content is 1.5 wt-%
Load EC OC Ash SO4= H2O Total PM
20% 0.06 0.23 0.06 0.54 0.42 1.31
40% 0.05 0.21 0.05 0.50 0.39 1.21
60% 0.05 0.20 0.05 0.48 0.37 1.15
80% 0.05 0.20 0.05 0.47 0.37 1.14
100% 0.05 0.20 0.05 0.48 0.37 1.16
In the atmosphere the oxidation of the emitted SO2 proceeds and in ship plumes sulphate be-
comes the dominant component of the PM. If all sulphur corresponding to 1% FSC would be oxi-
dised into H2SO4 and this H2SO4 would condense on particles in the ship plume, one would get an
emission factor for particulate H2SO4 of 30.6 g/kg fuel and, further, if also the water associated to
sulphate is accounted for an emission factor of 67 g/kg fuel is obtained. This numbers can be com-
pared to the typical EFPM that are a few grams per kg fuel.
While some measurements indicate that about 50 - 70% of the total suspended particles (TSP)
could be as PM2.5 and the remainder as PM10 (Cooper, 2003) other studies show that as for other
diesel engines the emissions are dominated by particles with diameters less than 1 µm (i.e. TSP =
PM10 = PM2.5). There are also studies that show the presence of larger (tar-like and reentrained) par-
ticles in the exhaust from slow speed engines using heavy fuel oil (Lyyränen et al., 1999; Fridell et
al., 2008; Moldanova et al., 2009) indicating that TSP may be larger than PM10. One can anticipate
that the particle size distribution will be dependent on fuel type, engine type, operation and age of
the gas plume.
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Emissions factors for PM number concentration
Emission factors for particle number concentrations are in the order of magnitude of 1016
/kg fuel.
Measurements, presented by Petzold et al. (2010), on a 4-stroke MSD burning RO show emission
factors for total particle number, EFN, between 1 and 4.5 x 1016
/kg fuel, with a positive correlation
between EFN and the engine load (Figure 9a). Airborne measurements in ship plumes have shown
EFN of the same order of magnitude but a factor of 2-3 lower (Lack et al., 2009; Petzold et al.,
2008; Murphy et al, 2009) (Figure 9a). Petzold et al. (2010) investigated the volatility of the emitted
particles in exhaust from a 4-stroke MSD test engine using a thermo denuder. They found that 2/3
of the particles at high load and 1/3 at low load were volatile and that the number of non-volatile
particles did not change for loads >20%. The increase in total particle emissions with load by a fac-
tor of 3 was almost entirely attributed to sulphuric acid-water droplets. Figure 9b shows the number
concentrations of particles in the accumulation mode, i.e. those with diameters in the range 0.1-3
µm, measured on test engines and in ship plumes.
a) b)
Figure 9. Emission factors for particle numbers measured on test engine burning RO with FSC 2.21 and in air-
borne measurements in ship plumes. a – total and non-volatile particles, b – particles in accumulation mode.
(from Petzold et al., 2010, data in Table 1)
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Emissions factors for PAH and benzo(a)pyrene
Polycyclic aromatic hydrocarbons (PAH) are compounds that consist of fused aromatic rings and do not contain heteroatoms or carry substituents. PAH cover a large group where naphthalene is the simplest species. There are several different groupings of PAH compounds defined for criteria pol-lutant critical levels. Widely used are EPA‟s 16 priority PAH “PAH-16” and EPA‟s 7 carcinogenic “PAH-7‟. In Europe “Total PAH-6” and “Total PAH-4” are defined for emission reporting to the European Commission (EC, 2000). Species included in these groups are shown in Table 9.
Table 9. PAH compounds and groups as defined by EPA and EC.
PAH species
Naphthalene
EP
A‟s
PA
H-1
6
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Pyrene
Benzo(a)anthracene
EP
A‟s
PA
H-7
Chrysene
Dibenzo(ah)anthracene
Benzo(a)pyrene
EC
‟s
Tota
l P
AH
-6
EC
‟s
Tota
l P
AH
-4
Benzo(b)fluoranthene Benzo(k)flouranthene Indeno(1,2,3-cd)pyrene
Benzo(ghi)perylene
Fluoranthene
There are only few data on emissions of PAHs from shipping. Publications of Lloyds (1995),
Cooper et al. (1996), Cooper (2001; 2003) and Agrawal et al. (2008; 2010) present a limited set of
Emission Factors of PAHs for a range of marine engines covering the most commonly used marine
fuels. Publications of Cooper et al. and Agrawal et al. are in agreement in that napthalenes and phe-
nanthrenes account for 80-90% of the measured PAH species. Cooper and Gustafsson (2004) pre-
sented, based on the first 4 publications, EFPAH for the EC‟s “Total PAH-4” for different engines
and fuels. The data used, however, do not cover the whole presented emission matrix. Comparing
these EFs with data from individual measurements found in literature one can observe that 1) the
measured EFs are largely variable with fuel and engine operation mode but relatively large variabil-
ity is present also for data obtained at similar conditions, 2) agreement between different EF esti-
mates for marine engines at full load operation using marine distillate fuels seems fairly good and
the EF is ~1x10-6
g/kWh, 3) different EF estimates for engines using heavy fuel oil differ for PAH-4
by factor 100 at most, Cooper and Gustafsson (2004) being lower than Agrawal et al. (2008b,
2010). Measurements of Agrawal et al. indicate that emission factors of these species for engines
running on HFO are much higher than those for engines running on distillate fuel. Emission factors
for PAH (Total-4) benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene and indeno[1,2,3-
cd]pyrene are summarised in Table 10. Measurements reported by Agrawal et al. (2008b, 2010)
show that PAH emissions at low engine loads tend to be substantially higher than emissions at op-
timum load. Figure 10 shows differences between EFs of several PAH species and groups at differ-
ent engine loads and the same EFs at optimum engine load expressed relatively to the EF at opti-
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mum load. We can see that large increase in EFs is in the 15% load mode. However, large variabil-
ity in the data exists as can be seen on difference between data points at 50% engine load.
Table 10. Emission factors for PAH (Total PAH-4, EC, 2000), benzo(a)pyrene. benzo(b)fluoranthene, ben-
zo(k)fluoranthene and indeno[1,2,3-cd]pyrene; st.dev. is standard deviation of the data.
Engine
type
Fuel
type
Cooper and Gustafsson (2004)
Agrawal et al., 2008
75-85% load
Agrawal et al., 2010
75-90% load
at sea manoeuvring
g/kgfuel g/kWh g/kWh g/kWh st.dev g/kWh st.dev
Total PAH-4
SSD MD 3.2×10-5
5.92×10-6
5.37×10-6
SSD RO 3.1×10-5
6.05×10-6
5.46×10-6
1.5×10-4
1.4×10-4
1.3×10-3
3.8×10-4
MSD&SSD MD 2.9×10-5
5.95×10-6
5.54×10-6
5.3×10-6
7.9×10-7
MSD&SSD RO 2.8×10-5
6.02×10-6
5.38×10-6
GT&ST MD 2.0×10-5
6.00×10-6
5.94×10-6
GT&ST RO 2.0×10-5
6.10×10-6
6.05×10-6
Benzo(a)pyrene
SSD MD 5.4×10-6
9.99×10-7
9.07×10-7
SSD RO 5.1×10-6
9.90×10-7
9.17×10-7
1.2×10-4
1.2×10-4
2.0×10-4
1.2×10-4
MSD&SSD MD 4.9×10-6
1.00×10-6
9.02×10-7
MSD&SSD RO 4.7×10-6
1.01×10-6
9.03×10-7
1.7×10-6
2.5×10-7
GT&ST MD 3.3×10-6
9.90×10-7
9.90×10-7
GT&ST RO 3.3×10-6
1.01×10-6
1.01×10-6
Benzo(b)fluoranthene
SSD MD 1.1×10-5
2.00×10-6
1.81×10-6
SSD RO 1.0×10-5
2.01×10-6
1.81×10-6
3.9×10-6
2.3×10-6
2.1×10-5
6.1×10-6
MSD&SSD MD 9.8×10-6
2.01×10-6
1.82×10-6
6.9×10-7
1.0×10-7
MSD&SSD RO 9.3×10-6
2.00×10-6
1.83×10-6
GT&ST MD 6.7×10-6
2.01×10-6
1.83×10-6
GT&ST RO 6.6×10-6
2.01×10-6
1.83×10-6
Benzo(k)fluoranthene
SSD MD 5.4×10-6
9.99×10-7
9.07×10-7
SSD RO 5.1×10-6
9.95×10-7
9.17×10-7
5.9×10-6
1.9×10-6
6.5×10-5
1.3×10-5
MSD&SSD MD 4.9×10-6
1.00×10-6
9.02×10-7
1.4×10-6
2.1×10-7
MSD&SSD RO 4.7×10-6
1.01×10-6
9.03×10-7
GT&ST MD 3.3×10-6
9.90×10-7
9.00×10-7
GT&ST RO 3.3×10-6
1.01×10-6
9.15×10-7
Indeno[1,2,3-cd]pyrene
SSD MD 1.1×10-5
2.00×10-6
1.81×10-6
SSD RO 1.0×10-5
2.01×10-6
1.81×10-6
2.3×10-5
2.2×10-5
9.9×10-4
2.4×10-4
MSD&SSD MD 9.8×10-6
2.01×10-6
1.82×10-6
1.5×10-6
2.2×10-7
MSD&SSD RO 9.3×10-6
2.00×10-6
1.83×10-6
GT&ST MD 6.7×10-6
2.01×10-6
1.83×10-6
GT&ST RO 6.6×10-6
2.01×10-6
1.83×10-6
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Figure 10. Difference between emission factors of various PAH species and groups and emission factors of the
same PAH species/groups at optimum engine load of 75-85% expressed relatively to the EF at optimum engine
load (i.e. 1 means EF 100% higher than at optimum load) (data from Agrawal et al., 2008b and 2010).
All findings on EFs for PAHs are quite consistent with how PAHs are formed, which is during incomplete combustion of organic matter including the petroleum products. The EFs are then ex-pected to be higher from combustion of fuel with higher PAH concentration and at low load condi-tions. In publications dealing with PAH emissions from shipping only Cooper et al. (2001) analysed fuels for PAH content. They found PAH content of 1% in MGO and 6.6% in MDO (0.5%S).
Conclusions
This report summarizes emission factors of gaseous and particulate species from shipping. It shows a rather complex picture where emission factors for CO2 and SO2 are directly proportional to the C and S content in fuel burned, NOx and directly emitted particulate sulphate are more efficient-ly produced in efficient combustion meaning high engine loads while CO, VOCs, particulate BC, OC and PAHs are more efficiently produced in incomplete combustion meaning low engine loads. Emission factors are thus function of fuel type, fuel sulphur content, type of engine and load of en-gine used. The activity data needed for calculation of emission inventory is than fuel used (at least MGO+MDO and HFO) in different types of engines, including engines equipped with different clean technologies, information on fuel sulphur content plus part of fuel used under different engine loads. Considering that the changes of EF against the engine load mostly deviate for very low loads (15-25%), separation on cruise and manoeuvring would be sufficient.
Emission factors for CO2, NOx, SO2 CO and HC presented here are based on a large number of measurements in Lloyd‟s and IVL‟s databases. These emission factors are widely used, however many other data and compiled emission factors exist. We have not performed a complete review of data for these species as focus of this report is on PM. Data on emission factors for PM mass, num-ber and composition for shipping are very limited. The existing emission inventories of PM mass emissions from shipping use ENTEC data on PM mass emission factors (EC and ENTEC, 2002). The existing data on PM number and composition are reviewed here.
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References
Agrawal, H.; Malloy, Q. G. J.; Welch, W. A.; Wayne Miller, J.; Cocker III., D. R., (2008a). In-use gaseous and particu-late matter emissions from a modern ocean going container vessel. Atmos. Environ. 42, 5504–5510.
Agrawal, H.; Welch, W. A.; Miller, J. W.; Cocker III, D. R. (2008b). Emission measurements from a crude oil tanker at sea. Environ. Sci. Technol. 42, 7098–7103.
Agrawal, H., Welch, W.A., Henningsen, S., Miller, J.W., Cocker III, D.R. (2010). Emissions from main propulsion engine on container ship at sea. J. Geophys. Res. 115, D23205.
Cooper, D. A., and K. Peterson (1996), Hydrocarbon, PAH and PCB emissions from ferries: A case study in the Skagerak‐Kattegatt‐Oresund region, Atmos. Environ., 30, 2463–2473.
Cooper, D. A. (2001) „Exhaust emissions from high speed passenger ferries‟, Atmos. Environ. 35, pp 4189-4200.
Cooper, D. A. (2003). Exhaust emissions from ships at berth, Atmospheric Environment 37, 3917-3830.
Cooper, D., Gustafsson, T. (2004). Methodology for calculating emissions from ships: 1. Update of emission factors. SMED Project report 4/2004, www.smed.se.
EC (1999) Council Directive 1999/32/EC of 26 April 1999 relating to a reduction in the sulphur content of certain liq-uid fuels, http://europa.eu/legislation_summaries/environment/air_pollution/l21050_en.htm
EC (2005). Directive 2005/33/EC of the European Parliament and of the Council of 6 July 2005 amending Directive
1999/32/EC, http://europa.eu/legislation_summaries/environment/air_pollution/l21050_en.htm
EC and ENTEC UK Limited, 2002. Quantification of Emissions from Ships Associated with Ship Movements between Ports in the European Community. European Commission. DG ENV.C1.
Endresen, Ø., Bakke, J., Sørgård, E., Berglen, T. F., Holmvang, P. (2005). Improved modelling of ship SO2 emissions –A fuel based approach. Atmospheric Environment 39, 3621-3628.
European Commission (2000) „Guidance document for EPER (European Pollutant Emission Register) implementation‟ November 2000. Refers to Council Directive 96/61 EC concerning IPPC (Integrated Pollution Prevention and Con-trol).
Fridell, E., Steen, E., Peterson, K. (2008). Primary particles in ship emissions. Atmospheric Environment 42, 1160.
International Maritime Organization (IMO) (2009). Second IMO GHG Study 2009, London, UK; Buhaug, Ø., Corbett, J.J., Endresen, Ø., Eyring, V., Faber, J., Hanayama, S., Lee, D.S., Lee, D., Lindstad, H., Markowska, A.Z., Mjelde, A., Nelissen, D., Nilsen, J., Pålsson, C., Winebrake, J.J., Wu, W., Yoshida, K.
Jalkanen, J.-P., Brink, A., Kalli, J., Pettersson, H., Kukkonen, J., Stipa, T. (2009). A modelling system for the exhaust emissions of marine traffic and its application in the Baltic Sea area. Atmos. Chem. Phys., 9, 9209–9223.
Jalkanen, J.-P., Johansson, L., Kukkonen, J., Brink, A., Kalli, J., Stipa, T. (2011), ”Extension of Ship Traffic Emission Assessment Model for Particulate Matter and Carbon Monoxide”, in preparation
Kasper, A.; Aufdenblatten, S.; Forss, A.; Mohr, M.; Burtscher, H. (2007). Particulate emissions from a low-speed ma-rine diesel engine. Aerosol Sci. Technol. 41, 24–32.
Lack, D. A.; Corbett, J. J.; Onasch, T.; Lerner, B.; Massoli, P.; Quinn, P. K.; Bates, T. S.; Covert, D. S.; Coffman, D.; Sierau, B. et al. (2009). Particulate emissions from commercial shipping: Chemical, physical, and optical properties. J. Geophys. Res. 114, D00F04.
Lloyd‟s Register Engineering Services (1995). Marine exhaust emissions research programme. London, England.
Lövblad, G., Fridell, E. (2006). Experiences from use of some techniques to reduce emissions from ships. Swedish Maritime Administration, Göteborg, Sweden.
Lyyränen, J., Jokiniemi, J., Kauppinen, E.I., Joutsensaari, J. (1999). Aerosol characterisation in medium-speed diesel engines operating with heavy fuel oils. Journal of Aerosol Science 30, 771–784.
Moldanová, J.; Fridell, E.; Popovicheva, O.; Demirdjian, B.; Tishkova, V.; Faccinetto, A.; Focsa, C. (2009). Characteri-sation of particulate matter and gaseous emissions from a large ship diesel engine. Atmos. Environ. 43, 2632–2641.
Petzold, A.; Hasselbach, J.; Lauer, P.; Baumann, R.; Franke, K.; Gurk, C.; Schlager, H.; Weingartner, E. (2008). Exper-imental studies on particle emissions from cruising ship, their characteristic properties, transformation and atmos-pheric lifetime in the marine boundary layer. Atmos. Chem. Phys. 8, 2387–2403.
Petzold, A.; Weingartner, E.; Hasselbach, J.; Lauer, P.; Kurok, C.; Fleischer, F. (2010). Physical properties, chemical composition, and cloud forming potential of particulate emissions from marine diesel engines at various load condi-tions. Environ. Sci. Technol. 44, 3800–3805.
Sarvi, A., Fogelholm, C.-J., Zevenhoven, R. (2008). Emissions from large-scale medium-speed diesel engines: 1. Influ-ence of engine operation mode and turbocharger. Fuel Proc. Tech., 89, 510-519.
Winnes, H., Fridell, E. (2009) Particle emissions from ships; dependence on fuel type. Journal of Air and Waste Man-agement Association, 59, 1391–1398.