Marine Installation Manual 2022-03 7-3
7 Engine Emissions
7.1 Exhaust gas emissions
X62DF-S2.0
7.1.2 Regulation and calculation criteria for SO
x
emissions
Regulation 14 of MARPOL Annex VI specifies the limits for SO
x
. Such limits
are specifically defined for designated Emission Control Areas (ECA) as well as
globally. As shown Figure 7-3, the ECA limit has been gradually reduced from its
initial value of 1.5% to 1.0% (2010) and finally to 0.1% (2015). The global limit
has also been gradually reduced from its initial value of 3.5% (2012) to 0.5%
(2020).
Figure 7-3 Sulphur limits introduced by IMO according to MARPOL Annex VI
SO
x
Calculation criteria
Total SO
x
emissions are linked mainly to two factors. The first factor is the sulphur
content of the fuel, which must fulfill the requirements stated under Regulation 18
of
MARPOL Annex VI
. The second factor is the fuel consumption.
SO
x
emissions (as SO
2
) can be calculated with the following formula:.
Formula 7-2
where:
m
SOx
........... = Oxides of sulphur emissions [kg/h]
BSFC ..........= Brake Specific Fuel Consumption [g/kWh]
2.0 ..............= Molar mass ratio of sulphur to sulphur dioxide
SC ..............= Sulphur Content [%]
P
ME
........... = Power (Main Engine) [kW]
BSFC is a function of the engine type and power. Values for specific projects are
available from the
GTD.
100 1000
E
P