on-board emission measurements–no · obtainingthe correctedemission factor note that the no x...
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On-board emission measurements – NOX
Erik Fridell
2012-10-23
� Research and consultancy by IVL Swedish Environmental Research Institute
– around 200 employees
– engineers, economists, social scientists, geoscientists, chemists, biologists, agriculturalists, communicators etc.
� Independent- owned by a foundation (SIVL) in which both the Government and commercial life are represented on the Board
� Accredited laboratories
� More than 40 years' experience
– In continuous development since 1966
– Marine emissions measurements since 1989
On Board Measurements
• Measurements for NOX certificates in Sweden - Shipowners with low NOX
emissions get lower fairway and port dues
• Measurements for NOX certificates in Norway – NOX tax /fund system
• Research projects e.g.:• Ammonia slip measurements• PM measurements
Regulations, nitrogen oxides
0
5
10
15
20
1990 2000 2010 2020 2030
NO
X(g
/kW
h)
Year
NOX (g/kWh)
World
NOX (g/kWh)
ECA
Tier II from 2012, global
Tier III from 2016, NOX-ECAs
How to comply with Tier III?• Selective Catalytic Reduction• EGR + water?• LNG
Weighting of Test Cycles
Speed 100% 100% 100% 100%
Power 100% 75% 50% 25%
Weightfactor
0.2 0.5 0.15 0.15
Speed 100% 100% 100% 100% 100%
Power 100% 75% 50% 25% 10%
Weightfactor
0.05 0.25 0.3 0.3 0.1
E2for ME
D2for AE
Constant-speedtest cycles
Current Swedish certification is based on ME at 75% and AE at 50% power only
Obtaining the corrected emission factorNote that the NOX formation depend on ambient factors
NOx Emission Factors (g/kWh)
NOx corrected mass flow
MeasuredNOx
emission (ppm concentration)
MeasuredCO2,
CO, O2
emissions
Ambient factors
Inlet Air (Temp & RH)
Intercool. Temp
Ambient Press.
Fuel Carbon
(%)
Specific FuelConsumption
(g/kWh)
FuelDensity
FuelConsumption
(l/hr.)
Engine (brake)
power
Marine SCRSCR have been tested in Swedish watersfor about 15 years thanks to fairway duesreductions and customer pressure
SCR can reduce approx. 95% of NOX
� Deactivation
� Low temperature activity
� Ammonia slip
NOX and NH3 conc in exhaust – SCR system in short transfer
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
14:50:00 15:06:40 15:23:20 15:40:00
NH
3 (
pp
m)
0
50
100
150
200
250
300
350
400
450
500
NO
x (
pp
m)
NH3
NOx Horiba
NH3 slip measurement
Absorbent
Teflon hoseSond
Evacuating Pump
/ volume meter
Exhaust
Sampling & Analysis or On-line measurement
Laser Diode Spectrometer
Photometer
How to monitor NOX
� Continuous onboard
– Good for total emissions
– Monitor deactivation
– Translation from measured values to corrected value from measurement cycle?
– Ammonia slip
– Downtime?
� Factory measurement
– No control of deactivation
– No control of ammonia slip
– How to monitor that the system is used? (urea consumption)
� Onboard regular checks
– Corrected NOX EF
– Control of ammonia slip
– Urea consumption?
Thank you for your attention!
www.ivl.se
Regulations, sulphur
How to comply?• Low-sulphur fuel• Scrubbers• LNG
0
1
2
3
4
5
1995 2000 2005 2010 2015 2020 2025 2030S-c
on
ten
t in
fu
el
(%)
Year
S (%) World
S (%) SECA
S (%) EU ports
Scrubbers � The exhaust is brought in contact with scrubberwater (bubbling, or mist).
� SO2 reacts with salt and form ions.
� The water is treated and returned to sea
� Can be open withseawater or closed loop with freshwater and NaOH
� Established technology on land
SO2 (gas) + H2O + ½O2 ==> SO42- + 2H+
HCO3- + H+ ==> CO2 + H2O
Technical criteria for scrubbers
� Scrubbers in combination with heavy fuel oil is an alternative to use low-sulphur fuel
� Scrubbers will reduce the SO2 emissions to equivalent levels
� Scrubbers will to some extent reduce emissions of NOx and PM
� Sulphates and other substances will be emitted to sea with the washwater
Washwater criteria (IMO)
� pH – max 2 pH units below seawater
� PAH – 2.25 mg/kWh of ”PAH-phenanthrene equivalents”
– A means to monitor hydrocarbons
� Turbidity – 25 FMU
– Not good for monitoring PM
� Nitrates - max 12% of NOx in exhaust gas removed
– Risk for eutrophication
