Post on 21-Jan-2015
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SNG: A Renewable, Regional Biofuel.
Looking at Possible Markets
Thomas Cheneycheney (at) unbc.ca
What is SNG● SNG stands for synthetic natural gas created
by anerobic digestion or methanization of gasified wood .
● Renewable Power Methane is a related product
● Can be used in existing natural gas infrastructure.
Objectives● Introduce SNG
production methods
● SNG uses
● SNGs role as energy currency in renewable energy system1 MW SNG production facility at Gussing,
Austria
How SNGis Made from WoodFeedstock Pre-treatment
Gasification GasCleaning
Gasification
Methanization
CO2 removal, Compression
Gas Grid
SNG Markets● Space and Water
Heating○ Existing gas furnaces ○ Peak load for alternative
fuel systems● Power Generation
○ intermittent ○ peak load
● Vehicle Fuels○ Liquified bionatural gas○ Compressed bionatural gas
www.energy.alberta.ca -
Energy Efficiency● 60-70+% wood to SNG
on LHV basis)● ~ 90% including
cogeneration (● 10-15 % higher than
biomass to liquids efficiency (GM2012)
● Potential for polygeneration
● Allothermal and autothermal
● Low temperature gasification for efficient
~850 C
From ECN
Allothermal vs Autothermal
gasification heat produced outside of the gasifier
gasification heat produced inside the gasifier
Diagrams from Gassner and Marechal (2012)
Two Allothermal Design philosophiesSwiss-Austrian
● Steam Assisted gasification
● reforming tars in gasification
● Biodiesel gas cleaning requires cleaner gas ○ less efficient process
due to steam content
Dutch
● Uses simple low-steam content, gasification system
● Needs better tar cleaning system
● 6% higher modeled SNG production efficiency.
http://www.ecn.nl/docs/library/report/2010/m10050.pdf
Allothermal Gasification
● Higher capital costs○ $927-$1755 /KWth ○ complex system○ lower pressures to allow for
heat transfer by fluidization medium
● Slightly lower efficiency● Based on avoiding
requirement for oxygen generation on site.
Photo: www.aer-gas.de/index.php?l=C&m=A
Allothermal Gasification process in Gassner and Marechal 2012
Autothermal CFB Gasification
● Lower capital cost○ $1240-$521/KWth○ Simpler system○ pressurized gasification and higher methanization
pressure● Requires oxygen supply● Slightly higher efficiency than allothermal
systems
Autothermal Gasifier
From Gassner and Marechal (2012)
SNG Production Prices $/GJ
Larger and autothermal plants have lower costs. Based on Gassner and Marechal (2012) and adapted to British Columbian conditions
Low Wood Cost High Wood Cost
5 MW CFB $26.42 $33.23
20 MW CFB $18.76 $25.56
100 MW CFB $13.48 $19.62
5 MW FICFB $32.42 $39.45
20 MW FICFB $22.25 $29.28
100 MW FICFB $18.08 $24.81
ButSNG is so expensive!
Only when the costs of the carbon dioxide climate damage are ignored (Ackerman and Stanton, 2004)
A carbon price of $100 per tonne CO2 increases the cost of natural gas by $5 per GJ
SNG With Carbon Tax$ emissions mitigations cost
low wood cost High wood costs
5 MW CFB $388.49 $524.54
20 MW CFB $235.12 $371.16
100 MW CFB $129.51 $252.39
5 MW FICFB $508.36 $648.95
20 MW FICFB $305.09 $445.69
100 MW FICFB $221.64 $356.11
Biofuels $/TCO2 Reduction
SNG has competitive mitigation costs
SNG
From Fulton et al. (2004) Biofuels for Transportation. http://www.cti2000.it/Bionett/All-2004-004%20IEA%20biofuels%20report.pdf
GHG Effects of SNG ● Carbo et al (2011)
found significant potential to combine CCS with carbon capture and storage
● Net negative CO2 when combined with carbon capture and storage
www.climate101.org
Methane Leakage ● Depends on the quality of the grid
● Life-cycle analysis of shale gas and natural gas suggests limited impact of methane emissions from transmission.
Natural gas has better than GHG balance than coal!
Biomethane has even lower seeing role of combustion GHG
SNG USES
© Lasse Hejdenberg/Hejdlösabilder
With SNG any natural gas bus can be a biogas bus
Buses● Natural gas buses are
widely used● 150 units in Canada● $45,000 Capital
premium
Source: Marbek (2010)
Truck● 700- 900 miles range ● $70,000 more
expensive capital costs● Spark ignition and
HPDI (natural gas/diesel mixture)○ spark ignition 10% less fuel
economy.○ or 5% diesel mixture
Marine Traffic
LNG MS Stavangerfjord
● LNG becoming popular as a marine fuel due to large mobile "point" source of demand.
● Ferry in operation in Norway● Considered by BC Ferries (BC ferries uses 118 Million
liters of diesel p/.a) and Washington State Ferries
Norwegian LNG Ferry
http://baltictransportjournal.com/poland/last-of-four-lng-ferries-for-torghattan-nord,23.html
Rail LNG LOCOS
CN Rail exploring LNG propulsion
Biogas Train in Sweden
fr.wikipedia.org
Retrofit cost of 1 Million Euro 1.3 Million $ Canadian
Power generation
www.ecomagination.com
SNG Electricity generation● SNG works in existing natural gas generators
and turbines● Can provide flexible low capital cost biomass
power ● Natural gas turbines cost 1.2 Mil Canadian
per MW.
http://www.emr.gov.yk.ca/oilandgas/pdf/eagleplain_.pdf
Renewable Power Methane
http://www.iwes.fraunhofer.de/de/publikationen/uebersicht/2010/towards_100_integrationofresimulationscenariosandstoragebylinkin/_jcr_content/pressrelease/linklistPar/download/file.res/2010-049_Towards-Integration_NREL.pdf
Peak Load Heating● Technological and Economic
barriers● Biomass boilers high capital
costs ○ 5 MWth $ 600 per KWth○ Nat Gas. $196 per KWth
https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcRcml0wFkH4yJA2uYFq0Y546UUP55zcHFktcBeUARpm_v1CQ9uO
Challenges with biomass systems
● Turndown Ratio ○ Max prod: Min Prod
● Typically 3:1○ Load variation much
greater○ Long start up time for
solid biomass systems makes load following by start up and shutdown unfeasible
http://www.riebenbauer.at
Food vs Fuel?
Heat Pump System Limits● High capital cost● Air source units have
much lower heat production at low temperatures
● natural gas backup and peaking ○ SNG can replace fossil
natural gas
SNG Heating ● SNG Heating can work
where natural gas works, due to quick start-up of boilers and furnaces
● SNG is expensive so other options will likely make sense for baseload!
Flying on Liquified NG?XB-70
Boeing SUGAR Freeze
LNG vs HydrogenLBM greater energy storage density
· Liquid Biomethane 22.2 MJ/L· Liquid Hydrogen 8.5 MJ/L
Liquid hydrogen better energy KG/Mass· Liquid Biomethane 53.6 MJ/KG· Liquid Hydrogen 141.6 MJ/KG
LBM is a better fuel choice when volume is limited.
The decarbonization Triangle
H2
e-
Muradov (2013), DOI: 10.1039/c3ee22879g
CH4
CO2
H2OO2
Various energy currencies
4H2 + CO2 CH4 + 2H2O
ConclusionSNG offers ● energy efficient biofuel production● Second generation biofuel● Transportation, heating and power
generation fuel● Low emissions● Existing infrastructure● Integration with Wind, Water Solar sources
through Renewable Power Methane.
Future Gas Well?Fu
Thanks!
www.us.all.biz -