Man L23/30DF, Project Manual

Page: 43 / 392

Exhaust gas components of medium
speed four-stroke diesel engines
The exhaust gas is composed of numerous constit-
uents which are formed either from the combustion
air, the fuel and lube oil used or which are chemical
reaction products formed during the combustion
process. Only some of these are to be considered
as harmful substances.
For the typical exhaust gas composition of a MAN
Diesel & Turbo four-stroke engine without any
exhaust gas treatment devices, please see tables
below (only for guidance). All engines produced cur-
rently fulfil IMO Tier II.
Carbon dioxide CO
2
Carbon dioxide (CO2) is a product of combustion of
all fossil fuels.
Among all internal combustion engines the diesel
engine has the lowest specific CO2 emission based
on the same fuel quality, due to its superior effi-
ciency.
Sulphur oxides SO
X
Sulphur oxides (SO
X
) are formed by the combustion
of the sulphur contained in the fuel.
Among all propulsion systems the diesel process
results in the lowest specific SOx emission based
on the same fuel quality, due to its superior effi-
ciency.
Nitrogen oxides NO
X
The high temperatures prevailing in the combustion
chamber of an internal combustion engine causes
the chemical reaction of nitrogen (contained in the
combustion air as well as in some fuel grades) and
oxygen (contained in the combustion air) to nitrogen
oxides (NO
X
).
Carbon monoxide CO
Carbon monoxide (CO) is formed during incomplete
combustion.
In MAN Diesel & Turbo four-stroke diesel engines,
optimisation of mixture formation and turbocharging
process successfully reduces the CO content of the
exhaust gas to a very low level.
Hydrocarbons HC
The hydrocarbons (HC) contained in the exhaust
gas are composed of a multitude of various organic
compounds as a result of incomplete combustion.
Due to the efficient combustion process, the HC
content of exhaust gas of MAN Diesel & Turbo four-
stroke diesel engines is at a very low level.
Particulate matter PM
Particulate matter (PM) consists of soot (elemental
carbon) and ash.
MAN Diesel & Turbo
1655210-7.3
Page 1 (2)
Exhaust gas components
D 10 28 0
L23/30DF, L28/32S-DF, V28/32S, V28/32H, L28/32S, L27/38S, L23/30S, L21/31S,
L16/24S, L28/32DF, L16/24, L21/31, L23/30H, L27/38, L28/32H
2016.02.22