The fuel gas quality is measured as a methane number. By means of a catalytic technology, in the presence of steam, the methane number of a low-grade fuel gas can be improved, allowing highest efficiency. Moreover, converting wasted side streams into fuel gas reduces green house gas emissions of the offshore & maritime industry.

1. © Wärtsilä
FUEL GAS QUALITY CONTOL
FOR GAS MODE OPERATIONS
METHANE NUMBER
4th April 2017, Chiba
Reetta Kaila
Product Manager, GasReformer
Wärtsilä Gas Solutions
Fuel Gas Handling
18.4.2017 GasTech2017 - WärtsiläGasReformer/ Reetta Kaila1
April 4-7, 2017 Makuhari Messe, Chiba, Japan

2. © Wärtsilä
LNG-powered vessels – Emissions in Gas Mode operation
18.4.20172
EMISSIONS IN LOW PRESSURE GAS MODE OPERATION
Wärtsilä 31DF
0
20
40
60
80
100
CO2 NOx SOx PM
DF/ Gas (LP) GD/ Gas (HP) Diesel/HFO
-25% -25%
-25% -37%
-85% -96%
-100% -100%
Shifting from diesel to gas
reduces GHG emissions by -25%
Low pressure (LP) operation with Wärtsilä Dual Fuel and WINGD 2-stroke engines
TIER III compliant NOx emissions (without SCRs)
SOx & PM free emissions
(without scrubbers)
GasTech2017 - WärtsiläGasReformer/ Reetta Kaila

3. © Wärtsilä
Methane Number (MN) is as a measure for knock
sensitivity and can be calculated from the gas
composition
18.4.20173
Fuel Gas Requirements for Gas Mode Operation: LHV & MN
METHANE NUMBER
Component MN
Methane CH4 100
Ethane C2H4 43
Propane C3H8 34
Butane+ C4H10+ 10
Carbon dioxide CO2 200
Nitrogen N2 200
Hydrogen H2 0
Wärtsilä Methane Number Calculator
http://www.wartsila.com/products/marine-oil-gas/gas-solutions/methane-number-
calculator
Derating required
Lower performance
Better knocking
resistance
• Lower heating value, LHV > 28 MJ/Nm3
• Methane Number, MN > 80
GasTech2017 - WärtsiläGasReformer/ Reetta Kaila

4. © Wärtsilä
• The natural gas composition varies substantially
between the various production fields.
• LNG quality depends also on the LNG train and is
affected by aging when stored:
Generally LNG contains more C2+
hydrocarbons than pipeline NG
• No CO2
• Negliglible N2
MN between 65 – 85
18.4.20174
LNG Composition and Quality as a Fuel Gas
LNG QUALITY
Typical LNG composition
CH4 >90%
C2-C4 < 10%
N2 < 4%
LNG tank
Boil-off gas (BOG)
Heat
ingress
The lighter fractions will boil-off first, resulting in a
gradual increase of density of the remaining part
Density differences
cause rollover
GasTech2017 - WärtsiläGasReformer/ Reetta Kaila

5. © Wärtsilä 18.4.20175
Examples of NG and LNG compositions and Methane Numbers
LNG COMPOSITION
Typical
compositions
Vol% CH4 PIPELINE NG
PRELUDE
LNG
QATAR LNG LOTOS LNG GASUM LNG
Methane CH4 100 % 83 % 83 % 90 % 93 % 99 %
Ethane C2H6 0 % 5 % 13 % 6 % 7 % 1 %
Propane C3H8 0 % 3 % 3 % 2 % 0 % 0 %
Butanes C4H10 0 % 1 % 0 % 1 % 0 % 0 %
Pentanes+ C5H12+ 0 % 1 % 0 % 0 % 0 % 0 %
Carbon dioxide CO2 0 % 6 % 0 % 0 % 0 % 0 %
Nitrogen N2 0 % 0 % 0 % 0 % 0 % 0 %
Molar weight (MW) kg/kmol 16.0 20.5 19.0 18.0 17.0 16.2
METHANE
NUMBER
100.0 69.0 67.5 72.5 83.7 95.6
Trace amounts of chlorine, fluorine, ammonia, hydrogen sulphide, particles.
GasTech2017 - WärtsiläGasReformer/ Reetta Kaila

6. © Wärtsilä 18.4.20176
Fuel flexibility on LNG-powered vessels
FUEL FLEXIBILITY
LNG bunkering vessel WSD59 10K
1. Flexibility in bunkering 2. Varying LNG quality 3. Full load operation
MN >80
LNG
NATURAL
BOIL-OFF
MN 65-85
GasTech2017 - WärtsiläGasReformer/ Reetta Kaila

7. © Wärtsilä
MN 65-85
LNG
NATURAL
BOIL-OFF
18.4.20178
Wärtsilä GasReformer to improve the Methane Number
GASREFORMER
MN >80
MN 100
Steam
Water
GasTech2017 - WärtsiläGasReformer/ Reetta Kaila

8. © Wärtsilä
LPG/BOG
(MN 20-40)
APG
(MN 40-60)
LNG
(MN 60-80)
18.4.20179
Wärtsilä GasReformer – a catalytic process
GASREFORMER
With help of steam
all heavier hydrocarbons of the
feed gas are turned into methane
Methane Number
of the product gas is
improved to100±5
Feed gas flexibility
• Fluctuating gas quality
• Presence of higher HCs (C2+)
• Low methane content, <50%
• Low methane numbers (MN20)
No side products
are formed
Energy content (98.5%) not lost
into side products (NGLs)
GasTech2017 - WärtsiläGasReformer/ Reetta Kaila

9. © Wärtsilä10
GASREFORMER PERFORMANCE
GasReformer Performance
10 MW APG GR
2x High Cube 20” container
18.4.2017
C2H6
3 %
C3H8
38 %
C4H10
12 %
C4H10
24 %
C5H12
11 %
C5H12
10 %
C6H14
2 %
CO2
1 %
Feed Gas, MN 20
C4H10
36%
C3H8
38%
C5H12
22%
GASREFORMER Unit
FEED GAS (MN 20-60) 170-175 g/kWh
PRODUCT GAS (MN 95-110) 195-260 g/kWh
FRESH WATER (for STEAM) 40-90 (200-300) g/kWh
OPEX 0.12-0.17 cent/kWh
H2
7 %
CH4
75 %
CO2
18 %
Product Gas MN 109
CH4
75%
GasTech2017 - WärtsiläGasReformer/ Reetta Kaila

10. © Wärtsilä
Prototype 2.7 MW GR Test Unit 1 MW
18.4.201711
GASREFORMER REFERENCE
GR Pilot 8 MW
Prototype Pilot unit Test unit
Year 2006-2008 2010-2012 2015-2016
Capacity 2.7 MW 8 MW 1 MW
Feedstock LPG Simulated APG LVOC/LPG/samples
MN, feed 40 100/75/65/52/43 20
MN, product 107 95-103 109
Engine 6L34SG 6L34SG 6L20DF
Dimensions ~5*2.5*3 m 9*2.5*3.5 m 6*2.5*2.9 m
Weight 22 ton 9.4 ton
Application and location - Drilling platform, South-China Sea Test site, Bermeo, Spain
Owner - CNOOC/NewField Wärtsilä
GasTech2017 - WärtsiläGasReformer/ Reetta Kaila

11. © Wärtsilä
VLGC/LPG carriers – BOG utilization in Gas Mode
12
APPLICATIONS: VLGC/LPG CARRIERS
LPGDF
ENGINES
GasReformer
C3
C4C1
Clean power
generation
C4 = Butane
C3 = Propane
C1 = Methane
LEG MN 43 DF derating to 73%
Propane MN 34 DF derating to 65%
C3/C4+ MN <30 DF derating is not feasible
18.4.2017
FULL RE-
LIQUEFACTION
PLANT
LIQUEFIED
PROPANE/
LPG
NATURAL
BOIL-OFF
BOG
MN 20-30
Natural Gas
MN 105
Consumption of LPG/ BOG:
• 20 days voyage
• average load of 14 MW
2.4% of a full 83k LPG cargo
For comparison:
Consumption of HFO:
• 14 MW power output
• ~ 20 000 ton/a fuel oil
• HFO price US$ 370/ton
US$ 7.4 Million/a
GasTech2017 - WärtsiläGasReformer/ Reetta Kaila

12. reetta.kaila@wartsila.com
#GasBassador #GasTech2017 #WartsilaKnowsGas
Thank you