internal use only 1 © wärtsilä wartsila proposals for exhaust gas emissions abatement p. tremuli...
TRANSCRIPT
1 © Wärtsilä
INTERNAL USE ONLY
Wartsila Proposals for Exhaust Gas Emissions Abatement
P. Tremuli 22.1.2008
2 © Wärtsilä
Agenda
1) Introduction
2) Key legislation
- Marine exhaust emissions legislation
- Wartsila engines vs. Legislation
3) Abatement technologies
- Wet Low NOx technologies
- Gas Engines
- SCR technology
- Scrubbing technology
- Common Rail
3 © Wärtsilä
Map to Lower Emissions
Exhaust GasEmission
Abatement
PRIMARY
METHODS
SECONDARY
METHODS
COMBUSTION
CYCLE
ENHANCEMENT
ENGINE
MODIFICATION
NOX
SOX
PARTICULATEMATTER
PM
LOW NOX
COMBUSTION
DOUBLE STAGETURBOCHARGING
WITH HIGH MILLER
COMMON RAIL
SMOKE
FUEL
CONSUMPTION
CO2
GAS ENGINES
WET METHODS
SELECTIVE
CATALYTIC
REDUCTION
SCR
SCRUBBER
PARTICULATE
FILTERS
DPF
4 © Wärtsilä
INTERNAL USE ONLY
KEY LEGISLATION
5 © Wärtsilä
Marine exhaust emissions legislation
• IMO (International Maritime Organisation)
• EU (European Union)
• SECA (Sulphur Emission Control Areas)
• EPA (Environmental Protection Agency - U.S.)
• Local Authorities
• Alaska
• California
• Canada
• River Rhine
• Norway, Sweden… (European Fee Incentive Programs)
• Voluntary Emission Reduction Programs
• American Bureau of Shipping ABS
• Bureau Veritas BV
• Det Norske Veritas DNV
• Lloyd's Register LR
• Registro Italiano Navale RINA
• Russian Maritime Register Of Shipping
6 © Wärtsilä
Transition of NOx emission limitsN
Ox g
/kW
h
20
07
20
11
20
15
20
20
2
8
16
IMO (slow speed engine)
IMO (high speed engine)
EPA NOx+HC
EU NOx+HC2
00
5
17
9.8
15
13.5~
10.2
7.8
6.3~
4.9
3.4
1.96
10.2
20
00
7.8
EPA Tier I
EPA Tier II
EPA Tier III
EPA Tier IV
-2 / -3.5 g/kWh
IMO Tier II
IMO Tier III
Norway proposal
IMO Tier III
Japan proposal
11
7 © Wärtsilä
Transition of SOx emission limits
Year
S in
fue
l (%
)
1
4
3
2
07 171615141312111009080605
IMO actual limitin Baltic SeaSECA area
IMO actual limitin
North Sea & EnglishChannel
SECA area
IMO actual Global cap
Option BGlobal cap
Option Bfor SECA areas
Option B1 (US)in costal areas X miles
from shore
Option B2 (BIMCO)Global Cap
Option B2 (BIMCO)for SECA areas
Option COnly distillates
8 © Wärtsilä
Next SECAs
9 © Wärtsilä
Wartsila Engines’ Portfolio vs. Legislation
SP
EC
IFIC
NO
E
MIS
SIO
NS
(g
/kW
h)
x
4
6
8
10
12
14
16
0 200 400 600 800 1000 1200 1400 1600 1800 2000
2
RPM
18
20
0
IMO limit
Low NOx comb.Wetpac E
SCR
W64 W46 W38 W32 W26 W20RTA
x
n < 130 rpm 17,0 g/kWh
130 rpm ≤ n < 2000 rpm 45 x n -0,2 g/kWh
n ≥ 2000 rpm 9,8 g/kWh
Wetpac
10 © Wärtsilä
Wartsila Gas Engines’ Portfolio vs. Legislation
SP
EC
IFIC
NO
E
MIS
SIO
NS
(g
/kW
h)
x
4
6
8
10
12
14
16
0 200 400 600 800 1000 1200 1400 1600 1800 2000
2
RPM
18
20
0
IMO limit
Low NOx comb.Wetpac E
SCR
W50DF W34DF
n < 130 rpm - > 17,0 g/kWh
130 rpm ≤ n < 2000 rpm -> 45 x n -0,2 g/kWh
n ≥ 2000 rpm - > 9,8 g/kWh
Wetpac H
Gas mode operation
11 © Wärtsilä
INTERNAL USE ONLY
ABATEMENT TECHNOLOGIES
12 © Wärtsilä
NOx vs. CO2C
O2
& P
art
icu
late
NOx
NO MIRACLES!!!NO MIRACLES!!!
Reduction Reduction targettarget
13 © Wärtsilä
Low NOx Combustion
– High combustion air temperature at injection
start
– Short injection period
– Good fuel atomization
– Optimal combustion space geometry
14 © Wärtsilä
Wet Low NOx Technologies
NOx reduction due to:
• Lower combustion air temperature through vaporization of the liquid water prior to and/or during combustion
• Increased heat capacity of the cylinder charge, which reduces the temperature increase during combustion
• Dilution of oxygen concentration in the cylinder charge
Wetpac H Wetpac EWetpac DWI
Three Wetpac technologies have been developed/tested:
Direct Water Injection Humidification Water-fuel-Emulsions
15 © Wärtsilä
Wetpac DWI (Direct Water Injection)
Strengths
• High NOx reduction level achievable: 50%• Water-to-Fuel ratio typically: 0.7• Low water consumption compared to Humidification • Water quality is less crucial compared to Humidification• Air duct system can be left unaffected – no risk for corrosion/ fouling of CAC, etc• Flexible system – control of water flow rate, timing, duration and switch off/on• Less increase of turbocharger speed and less drift towards compressor surge line compared to the Humidification method due to no increase of rec. temp. and less water flow – high engine load can be achieved and high (50%) NOx reduction also at full engine load• No major change in heat recovery possibilities• Good long term experiences with low sulphur fuels (<1.5%)
Weaknesses
• High fuel consumption penalty• Increased smoke formation especially at low loads
• Remedy: switch off or less water at low load• More complicated/expensive system compared to Humidification• Challenges in terms of piston top and injector corrosion with high sulphur fuels (>1.5%)
TechnologyH:\GHn\Env_ bookle t\section_ 7\s_7 A_13 .PPT
NOx Reduction - Primary Measures
Water
Water Pressure200 - 400 bar
Water Needleand
Fuel Needlein the Same
InjectorFuel Pressure
1200 - 1800 bar
Fuel
DWI system with “Tandem-nozzle”
TechnologyH:\GHn\Env_ bookle t\section_ 7\s_7 A_14 .PPT
NOx Reduction - Primary Measures - Principle of theDWI System with “Tandem Nozzle”
Flow fuse
High pressureWater Pump
Watertank
Water
Fuel
Water needle
Fuel needle
Solenoidvalve
Control unit
T
16 © Wärtsilä
Wetpac H (Humidification)
Strengths
• Only marginal increase of SFOC• Less complicated/expensive system compared to DWI• Flexible system – control of water flow rate and switch off/on
Weaknesses
• Lower NOx reduction (40%) compared to DWI (50%)• High water consumption compared to DWI
• Very clean water is required in order to avoid fouling/corrosion of CAC and air duct system
• Major change in heat recovery possibilities - less cooling water heat available for production of clean water• Water-to-fuel ratio 1,3÷2
• Turbocharger speed increase and drift towards compressor surge line due to increased rec. temp. and high water flow
• By-pass is required (anti-surge device)• Not possible together with pulse charging systems
• Full NOx reduction (40%) can not normally be achieved at full engine load and low loads
• Increased smoke formation especially at low loads• Remedy: switch off or less water at low loads
• Limited long term experience• Unacceptable corrosion observed in the air duct system including CAC on 500h endurance test with high sulphur fuel (3%)• Encouraging lab and field experiences (rather few hours) with low sulphur fuel and low NOx reduction levels (about 30%)
Evaporised water is partly re-condensingin the charge air cooler
Compressor
Heat from cooling wateris reducing re-condensing
Water injection 130-135 bar
Saturated air40…70°C
Injected water mist is evaporated and hot air after compressor is cooled tosaturation point
Unevaporised watercaptured in WMC and re-circulated
Standard Wetpac H unit
17 © Wärtsilä
Wetpac E (water-fuel Emulsions)
Strengths
• Only marginal increase of SFOC • Reduced smoke formation especially at low load• Low water consumption compared to Humidification
• Water-to-fuel ratio 0,3• Almost similar to that of DWI, but due to low NOx reduction the water consumption is low
• Water quality is less crucial compared to Humidification• Less increase of turbocharger speed and less drift towards compressor surge line compared to the Humidification method, due to no increase of rec. temp. and less water flow – high engine load can be achieved• No major change in heat recovery possibilities
Weaknesses
• Low NOx reduction potential (15-20%)• Limited flexibility
• Increased smoke formation and poor engine performance due to too large nozzles in case of switching off the system
• Increased mechanical stress on the fuel injection system in case ”standard” nozzles are used
• Limited long term experience• 400h endurance test showed extreme turbine nozzle ring fouling
• Root cause was very bad water quality
Water droplets inside fuel droplet
Fuel Oil droplet
18 © Wärtsilä
0
0.5
1
1.5
2
2.5
3
0 10 20 30 40 50 60
Wetpac – NOx reduction potentials and typical fuel consumption penalties
DWI
Emulsion
In
crea
se o
f S
pec
ific
Fu
el C
on
sum
pti
on
(%
)
NOx reduction (%)
Humidification
Achievable withWetpac H (Marine)
Achievable withWetpac DWI
Achievable withWetpac E
19 © Wärtsilä
NOx Reduction with Selective Catalytic Reduction (SCR Catalyst)
Control Control UnitUnit
BoilerBoiler
Urea Urea TankTank
Dosing Dosing UnitUnit
Compressed Compressed AirAir
SilencerSilencer
Selective Selective Catalytic Catalytic ReactorReactor
Pumping Pumping UnitUnit
Performance NOx reduction 85-95%
HC reduction 75-80%
Soot reduction 20%
Sound Attenuation 20 dB (A)
Operation Temperature Span 300-500 °C
Fuel MGO/MDO/HFO
Specific costs Invest cost 25-50 €/kW
Running cost 2-4 €/MWh
20 © Wärtsilä
Marine SCR reference list 2006 Totally more than 100 engines with SCR installed
Vessel Engines Delivery Fuel Notes
Aurora af Helsingborg 1 x WV6R32 1992 MDO
Silja Serenade 1 x WV8R32 1995 HFO 0.5% S
Silja Symphony 1 x WV8R32 1995 HFO 0.5% S
Gabriella 1 x WV6R32 1997 HFO 0.5% S Retrofit
Thjelvar 2 x WV4R32 + 4 x WV12V32 1997 HFO 0.5% S Compact SCR
Birka Princess 4 x WV12V32 + 2 x WV6R32 + 1 x WV4R32
1999 1999
HFO 0.5%S HFO 0.5%S
Compact SCR, retrofit Compact SCR, retrofit
M/V Spaarneborg 1 x 7RTA52U + 2 x W6L20 1999 HFO + MDO
M/V Schieborg 1 x 7RTA52U + 2 x W6L20 1999 HFO + MDO
M/V Slingeborg 1 x 7RTA52U + 2 x W6L20 2000 HFO + MDO
Visby 4 x 12V46 + 3 x 9L20 2000 HFO Compact SCR
Gotland 4 x 12V46 + 3 x 9L20 2000 HFO Compact SCR
Birka Exporter 1 x WV16V32 2000 HFO Compact SCR, retrofit
Birka Transporter 1 x WV16V32 2002 HFO Compact SCR, retrofit
Birka Shipper 1 x WV16V32 2001 HFO Compact SCR, retrofit
Birka Paradise 4 x 6L46 + 4 x 6L32 2002 HFO Compact SCR
Tallink Victoria 4 x 16V32LNE + 3 x 6R32LNE 2002 HFO Compact SCR
Balticborg 1 x 9L46C 2003 HFO <1%S
Bothniaborg 1 x 9L46C 2004 HFO <1%S
Normand Skipper 4 x 6R32LNE 2005 MDO
Tallink Galaxy 4 x 16V32LNE + 3 x 6R32LNE 2006 HFO
Ulstein 275 4 x 9L20 2006 MDO Ulstein 276 4 x 9L20 2007 MDO Flekkefjord 186 2 x 8L32 + 1 x 6L20 2007 MDO
21 © Wärtsilä
Dual Fuel
Used on W34DF and W50DF
* ** ** * **
******
** **
***
**
Intake ofair and gas
Compression ofair and gas
Ignition bypilot diesel fuel
Otto principle
Low-pressure gas admission
Pilot diesel injection
Gas mode: Ex. In. Ex. In.Ex. In.
Intake ofair
Compression ofair
Injection ofdiesel fuel
Diesel principle
Diesel injection
Diesel mode:Ex. In. Ex. In.Ex. In.
22 © Wärtsilä
Dual Fuel
Operatingwindow
The
rmal
effi
cien
cy [
% ]
NO
x em
issi
ons
[ g /
kW h
]
BM
EP
[ ba
r ]
Air / Fuel ratio
Knocking
Mis
firin
g
Optimum performancefor all cylinders
23 © Wärtsilä
Emissions
0%
20%
40%
60%
80%
100%
120%
HFO DF
CO2 NOX SOX
CO2 -30%
NOX -85%
SOX -99.9%
– Very low particulate emissions– No visible smoke– No sludge deposits
24 © Wärtsilä
LNG tanks
LNG tank location• Rule requirements
– From side: B/5– From bottom: B/15 or 2 m
(the lesser)
• Novel location in cruise ships– In centre line casing– Free ventilation to open air– Fire insulated space– “Drip tray” below tanks
capable of containing the fuel of an entire tank
25 © Wärtsilä
LNG in Europe
Import terminal
Export terminal
25 © Wärtsilä
26 © Wärtsilä
SOx - Solutions for compliance
Clean exhaust gas
Fuel Solutions
Amongst the solutions on the fuel strategy side, we can list the following:
– Running MDO– Balance emissions by running
different fuel on different engines– Running on 1,5%S fuel– Blend fuel before use
Not much can be done at engine level to reduce sulphur emission:what is in the fuel will be found in the exhaust gases.
Cleaning exhaust gases with scrubber has a long track record on land base applications. The technology is about to be applied for Marine installation.
– Seawater scrubber– Freshwater scrubber
+ alkaline additive– Combination of the above
• Emission trading could have been a solution but it is not yet in place for SOx.• Cold ironing by definition is only proposed at berth, an consequently can not be
considered as a solution for SOx abatement at sea.
27 © Wärtsilä
General outlook of Marine Scrubber System
Scrubber
pHpH
NaOH unitFresh or Greywater source
WaterTreatmentHeat
Exchanger
Seawater pH management with seawater
pH
• This process is an closed loop system.
• Closed loop needs freshwater, to which NaOH is added for the neutralization of SOx.
Exhaust Gas
28 © Wärtsilä
Equipment Compounds 1 (all-in-one)
29 © Wärtsilä
Equipment Compounds 2 (all-in-one)
30 © Wärtsilä
Fuel Injection – Common Rail
31 © Wärtsilä
Fuel Injection – Common Rail
Used on W32, W38 and W46
32 © Wärtsilä
Extreme Miller cycle
• NOx reduction up to 50%
• 10% Fuel consumption reduction
• Thermal loading enhancement
•Good load acceptance with Variable Inlet closing
33 © Wärtsilä
Extreme Miller
34 © Wärtsilä
2 Stage Turbocharging
35 © Wärtsilä
Thank you!