Transcript Energy Storage in Carbon Neutral Fuels

Energy Storage in Carbon
Neutral Fuels
Leon Di Marco
FSK Technology Research
OU Energy 3 April 2014
Why Store Renewable Energy in
HydroCarbon Fuels ?
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High Energy Density
Compatible with infrastructure etc
Made from water and carbon dioxide
Used for transport and power generation
Can be gas - methane CH4 , or liquid octane C8H18 , diesel , kerosene
• Potentially lots of excess wind + solar
Making Components
• Hydrogen from electrolysis with renewable
electricity - high energy + efficiency
• Future PhotoElectroCatalysis direct solar
• Carbon Dioxide captured from air
(CO2 from fossil flue gas has high net
emissions) or BECCS
• CO2 air capture in early stages of
development
Direct Air Capture of CO2
• Use wet (dry) alkali to chemically bond to
400ppm airflow at 2 m / s
• Can be KOH or NaOH but very strong bond
energy for recycling alkali
• Alternatives - carbonate / bicarbonate cycle
Na2CO3 + CO2 + H2O < > 2 NaHCO3
• Ammonia (carbonate) or amines (but not
MEA) or “ionic liquids”
Synthesising Fuel
• Methanation a standard process - Audi
using CO2 from biogas for car e-gas
• Synthetic gas to liquid fuel(s)
Fischer-Tropsch catalysis is well understood
and used by Shell to make synthetic diesel
from methane in Qatar
• Very low net carbon emissions using
renewable components
Conversion Efficiency
• Air Fuel Synthesis currently 45% using
intermediate CO2 + H2 to methanol then
standard methanol to gasoline process
• 70% from future high efficiency process
using low energy CO2 capture and coelectrolysis of CO2 and H2O at high temp
• Waste heat used for air capture process and
CHP
Costs
• Mainly arise from making hydrogen
• More expensive than fossil fuel with low
carbon price - about twice
• Not necessarily prohibitive compared with
alternative low carbon transport solutions
• Power2Gas captures excess renewable
power that will otherwise be lost
Power2Gas 1
• IWES study shows wind power can create
390 TWhr = 2/3 of German 2010 demand
• Grid storage for fluctuation = 0.04 TWhr
but gas network storage = 217 TWhr and
X 10 greater output rate
• Conversion efficiency >60% and use spare
heat for CHP then use stored gas to fire
generators when wind power is low
Power2Gas 2
• Audi e-gas project with two 3.6 MW wind
turbines giving 53 GWhr / year
• 2,800 tonne bio CO2 makes 1000 tonnes e-gas
• Fuels 1500 A3 e-gas cars for 15,000km with 150
tonnes spare ( high efficiency turbo gas engines)
• Spare electricity powers 1000 A1 e-tron electric
cars for 10,000 km
• WTW emissions < 30 gmCO2 / km but life cycle
emissions of e-gas car lower than e-tron
Stored Carbon in Fuel
• German gas network stores 21 bn m3
=
14 Mtonne methane or 37 Mtonnes CO2
• 5 Tonne CO2 embedded per car so offsets
nearly 8 M cars or 20% of German fleet
• Better using liquid fuel with 1000 X density
so about 2 m3 to offset a car
• Large strategic oil reserves - Germany 11 M
m3 , UK 3 Mtonnes (?)
Current Activity
• Liquid Fuels from air + water
Air Fuel Synthesis ( UK)
Sunfire (Germany) , CRI ( Iceland )
e-gas methane Audi/Fraunhofer (Germany)
• Air Capture - Coaway, Kilimanjaro, Global
Thermostat, Carbon Engineering - ( US /
Canada ) , Carbon Cycle ( UK) ,
Climeworks ( Swiss ) 4 kg / day CO2
demonstrator = 1 Tonne / year
Original IEEE paper -2012
• Energy Storage via Carbon-Neutral Fuels Made
From CO2, Water and Renewable Energy
Proc IEEE Vol 100, No2, Feb 2012
• Richard Pearson, lead author, and Jamie Turner
Lotus Engineering , now BP and JLR
• Matt Eiseman on air capture - PARC , now
Brookhaven National Lab
• Peter Edwards Oxford Uni Chemistry team
New Work on UK Advanced Fuels
• For DfT Advanced Fuel Consultation 2014
• Looks at integrated transport solution with
energy storage for power system - P2G
• Estimates that 10 million advanced hybrid
cars can be fuelled for 10km using a 10GW
wind farm in 2030, meeting EU urban rule
• Fuel cost > £1 / litre but only £ 0.05 / km
Future Work
• Fuel component R&D - CO2 Chem
network
• Integrated manufacturing plant
• High efficiency transport development
• Need for techno-economic model for UK
with transport and power sector
• © FSK Technology Research 2014
References
• Goeppert et al , Air as the renewable carbon source of the
future,
Energy Env Sci 2012 , Vol 5
• Graves et al , Sustainable Hydrocarbon Fuels by recycling
CO2 and H2O with renewable or nuclear energy,
Renew Sust Energy Rev , Vol 15, 2011
• Sterner M, Renewable Power Methane , Fraunhofer
IWES
( PhD thesis etc)
• Kay et al, Powering Ahead, RAC / Ricardo 2013
• Advanced Fuels : call for evidence , DfT Dec 2013
Negative Emissions ?
• about 2 Ttonnes of fossil CO2 already emitted - half is now
in the sea , so about 2 kgCO2 / m2 in air = 45 mol / m2
• Desert Solar power = 270 W / m2 or 8 GJ / m2 / year
• Enough solar energy to remove 32,000 mol CO2 per year
• Remove 1Ttonne over 40 years ie 25 Gtonne / year
• So use 1/ (40 X 750) = 1/30,000 of earth area = 20,000km2
this is 1% of Saudi land
• Machine aperture size 1000 km2 - say 10m X 100km
“Great Wall of Carbon”
• 40 X 500km oblong with 2,500 strips every 200m