Upload
nguyenanh
View
221
Download
2
Embed Size (px)
Citation preview
The Potential of GTL Diesel to Meet Future Exhaust Emission Limits
Paul Schaberg, Sasol Technology
12th Diesel Engine-Efficiency and Emissions Research Conference, Detroit, August 20-24, 2006
Co-authors
DaimlerChrysler AGHans-Otto HerrmannStefan KeppelerWalter Friess
SasolChevron Consulting Ltd Mark Schnell
Sasol Technology
Johan Botha
Presentation overview
Status and availability of GTL diesel fuel
Impact of GTL diesel fuel on performance and emissions
Without engine modifications
With software adaptation
With hardware adaptation
GTL Demonstration Vehicle
Conclusions
GTL diesel fuel production Oryx GTL, Qatar
330 MM 1 000 bpdSCF/d
LPGnatural gas 24 000 bpd
diesel
9 000 bpd naphtha Commercial
production in 2006
ProductProduct workupworkup UtilitiesUtilities pipepipe rackrack GasGas feedfeed
CurrentCurrentglobal marketglobal market13,500,00013,500,000
GTL diesel Fuel Meeting diesel demand growth
GTL industry potential GTLGTL industry potential GTL diesel capacity ~600 000diesel capacity ~600 000
Cumulative additionalCumulative additionalglobal demandglobal demand
~4 600 000~4 600 000
20052005 20152015
AnnualAnnualglobal growthglobal growth
(at 3%)(at 3%)
4%4%13%13% ofof NEWNEW demanddemand
ofof TOTALTOTAL demade ndmand
Sasol Chevron potential GTLSasol Chevron potential GTL diesel capacity ~300 000diesel capacity ~300 000
Oryx GTLOryx GTL24 00024 000
Global dieselGlobal diesel demanddemand
~13.5 million~13.5 million
((~~ 1 500 ppm S)1 500 ppm S) (volumes in bpd)(volumes in bpd) (~ 50 ppm S)(~ 50 ppm S)
5
Properties of SasolChevron GTL diesel fuel
Clear, almost odourless liquid
Highly paraffinic (total aromatic content <1%, polycyclic aromatic content < 0.05%)
Density ~ 0.77 kg/l
H/C ratio ~ 2.10 mol/mol
Energy content ~ 47.1 MJ/kg
Cetane number >>70
Very low sulphur (< 1ppm)
Good thermal stability
Impact of GTL diesel fuel on performance and emissions : Review
40 40
-100
Heavy Duty
Part
icul
ates
(%)
Light Duty
MB C220 CDI vehicle with EU3 and EU4 calibrations
With software adaptation
20 20
0
-20
-40
-60
-80
0
-20
-40
-60
-80
-100 -40 -30 -20 -10 0 10 20 -40 -30 -20 -10 0 10 20
NOx (%) NOx (%)
Potential reductions in all regulated emissions (HC, CO, NOX, PM), as well as in CO2 and other unregulated emissions
Part
icul
ates
(%)
Source : SAE Paper 2003-01-0763, NREL
Impact of GTL diesel fuel on engine performance and emissions
No engine modifications
+ • HC reduction potential 90% • CO reduction potential 90% • PM reduction potential 35%
• Limited NOX-reduction
- • Slightly reduced power • Higher volumetric
fuel consumption
Vehicle: MB E220 CDI
GTL diesel fuel offers high emission reduction potential for non-adapted engines. These benefits can be utilized in existing vehicle fleet.
Impact of GTL diesel fuel on engine performance and emissions
Software adaptation only
+
-
• Simultaneous particulate and NOX reduction of up to 35%
• Must still meet emission limits with conventional diesel
• Higher volumetric fuel consumption
Software adaptation would facilitate NOX reduction from engines operated with GTL diesel fuel. However, potential is limited by certification requirements.
Impact of GTL diesel fuel on engine performance and emissions
Hardware adaptation offers maximum potential to reduce emissions at lower cost. This scenario requires dedicated GTL engines.
Hardware and software adaptation
+ • Potential to reduce all engine-
out emissions • No power loss • Reduced overall cost
- • Dedicated engine • Requires new standard
to utilize full potential
Project Target: 0.08 g/km NOx (NEDC) without active NOx aftertreatment
Baseline EU4 Engine
GTL fuel + hardware adaptation Requires ~ 70% NOx-Reduction
Engine and vehicle data
Vehicle details : Mercedes Benz E320 CDI Model year : 2005
Gearbox : 7-speed automatic transmission
Emission status : EU 4 (baseline)
Emission test cycle : New European Driving Cycle NEDC 2000
Vehicle weight class : 4000 lbs
Engine details : Mercedes Benz OM642 Configuration : 3 litre, 6 cylinders, 72 degree V
Compression ratio : 18:1 (baseline)
Fuel management : Common rail, direct injection, piezo injectors, 1600 bar peak pressure
Air management : VGT turbocharged, intercooled
Emission control : Cooled EGR, inlet swirl control, closed coupled DOC, DPF
Rated torque : 510 Nm from 1600 to 2800 rev/min
Rated power : 165 kW at 3600 rev/min
Hardware optimization strategy
Relative NOx (%)
Rel
ativ
e So
ot (%
) EU 4 Engine
CR = 15:1 + recalibration
Adapted injector configuration + recalibration
Two-step hardware optimization strategy:
Step 1: Reduction of compression ratio (CR=15:1)
Step 2: Adaptation of injector parameters
Due to availibility of a DPF, main focus of engine
optimization was reduction of nitrogen oxide
emissions
Smok
e
Impact of compression ratio on emissions
NOX relevant engine operating point
HC relevant engine operating point
CR 16:1 GTL Diesel Fuel
1800 rpm bmep = 8.9 bar
CR 15:1 GTL Diesel Fuel Optimized Injection Strategy
CR 15:1 GTL Diesel Fuel
Hyd
roca
rbon
Em
issi
ons
CR 16:1 GTL Diesel Fuel
1000 rpm bmep = 4.2 bar "cold conditions"
CR 15:1 GTL Diesel Fuel Optimized Injection Strategy
Oxides of Nitrogen Oxides of Nitrogen
GTL diesel fuel + compression ratio reduction offers significant improvement potential for NOx at higher load, while maintaining low HC emissions at low
temperature operating conditions
-20
100
Crank Angle [deg]
10
20
30
40
50
60
-20.0
0.0
20.0
40.0
60.0
80.0
100.0-4-20246
0
20
40
60
80
100
-6.0
-2.0
2.0
6.0
-20.0
20.0
60.0
100.0
140.0
-20
100
Crank Angle [deg]
-4-20246
Impact of GTL diesel fuel on combustion parameters
1000 rpm, bmep = 4 bar, CR = 16:1 1800 rpm, bmep = 8,9 bar
EU Diesel EU Diesel, CR = 16:1 GTL Diesel Fuel
GTL Diesel Fuel CR = 15:1
Cyl
inde
r Pre
ssur
eH
eat R
elea
se R
ate
Rat
e of
Cyl
. Pre
ssur
e R
ise
Inje
ctor
Sig
nal
Inje
ctor
Sig
nal
Rat
e of
Cyl
. Pre
ssur
e R
ise
Cyl
inde
r Pre
ssur
eH
eat R
elea
se R
ate
-30 -20 -10 0 10 20 30 40 50 -30 -20 -10 0 10 20 30 40 50
Crank Angle [deg] Crank Angle [deg]
GTL Demonstration VehicleEmissions and performance
120
Part
icul
ate
Filte
r
0.08 g/km
0.5 g/km 0.05 g/km
0.005 g/km
Result
0 NOx CO THC PM
Exhaust Emissions
100
80
60
Rel
ativ
e Le
vel (
%)
40 EU4 limit EU4 production vehicle Project target20
EU4 Limit
Project TargetEU4 Production Vehicle
Result
GTL Demonstration VehicleEmissions and performance
0
20
40
60
80
100
120
Rel
ativ
e Le
vel (
%)
Part
icul
ate
Filte
r
0.08 g/km
0.5 g/km 0.05 g/km
0.005 g/km
165 kW
EU4 limit
Project target EU4 production vehicle
Result
NOx CO THC PM CO2 Vol FC Maximum
Exhaust Emissions Fuel Consumption Power
Project emission targets were achieved without compromising maximum power or energy efficiency.
Conclusions
GTL diesel fuel is an enabler for cost-efficient reductions in exhaust emissions
Engine efficiency and performance need not be compromised by the adaptation for GTL diesel fuel.
The results corroborate that clean fuels are one means to comply with future, more stringent emission regulations in a cost-effective manner.
Potential future development of such dedicated “GTL diesel engines” will be determined by the widespread availability and the cost of GTL diesel fuels. Also, a standard for such fuels would have to be developed.