Non-Electricity Applications & Nuclear Hydrogen · Global Nuclear Energy Partnership (GNEP) and...
Transcript of Non-Electricity Applications & Nuclear Hydrogen · Global Nuclear Energy Partnership (GNEP) and...
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Hydrogen Production and Potential Non-Electricity Applications of Nuclear
Energy
Ramesh SadhankarJuly 9, 2008
Atomic Energy of Canada Ltd.Presented to
WNU Summer Institute 2008, Ottawa
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Outline of Presentation
• Background/rationale– Potential applications– Current and future generation reactor capabilities– Sustainability
• Low-temperature applications– Desalination– District heating
• High-temperature applications– Hydrogen Production
Hydrogen demand/supplyCurrent production methodsHydrogen production using nuclear energyCost of nuclear hydrogenSafety Hydrocarbon fuels from hydrogen
– Other process heat applications• Concluding remarks
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Present Generation Reactors
H
CH
TTT −
≤η• Schematic of CANDU-6 reactor•Reactor outlet 310º C, 9.9 MPa(g)•Gross turbine efficiency 35.3%
• Almost exclusively used for electricity generation• Power conversion efficiency ~35%•Is it possible to use waste heat to replace fossil fuel?
•Current generation reactors – are mostly water cooled•Outlet temp. are relatively low for process heat applications•Thermal efficiency of power conversion is low ~ 35%•2/3rd of thermal energy is discarded to the atmosphere – or a body of water•If the low level heat is instead used for heating, it will improve overall efficiency, save fossil fuel and reduce GHG emission.
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2000 2020 2040 2060 2080 2100
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illio
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FR Introduced 2050
FR Introduced 2030Known Resources
Speculative Resources
Uranium Resources
•Reducing GHG emissions by replacing fossil fuel by nuclear thermal energy•Sustainability – potentially abundant supply of fissile/fertile material
•Current thermal reactors use open (once-through) fuel cycle based on fissile U-235
•Natural uranium has only 0.7% U-235
•In future, symbiosis of thermal reactors and fast reactors will be able to close the fuel cycle
•Uranium utilization increases by more than 60 fold•Thorium is more abundant than uranium
Rationale Behind Non-Electricity Applications of Nuclear Energy
•Replacement of fossil fuel by nuclear heat will significantly reduce the GHG emissions• If the nuclear expansion continues with current design of reactors, the uranium resources may not be sufficient. Various studies predict 30-100 years of supply from the known resources.•Closing of the fuel cycle is being pursued by various international initiatives – like Global Nuclear Energy Partnership (GNEP) and Generation IV International Forum (GIF). Sodium Fast Reactors have already been demonstrated before. Gas Fast Reactors are under development through GIF.•Closing of the fuel cycle will guarantee virtually non-exhaustive supply of fertile and fissile material. •References:
•Technology Road Map, Generation IV International Forum, 2002•Can Uranium Supplies Sustain the Global Nuclear Renaissance? World Nuclear Association, www.world-nuclear.org
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Relative Energy Potential of Canadian Natural Resources
Natural Gas1%
Oil5%
Coal11%
U-235 83%
Uranium100%
Natural Gas0%Oil
0%
Coal0%
Fissile Uranium
Total Uranium
•Canada is the largest producer of uranium and has the second largest proven reserve of uranium deposits – only next to Australia.•Canada also has substantial oil and natural gas reserves and abundant oil sands reserves. •Current reactors use only U-235 isotope which is ~0.7% in the mined uranium. Even then uranium represents 83% of the total energy reserves•If uranium utilization is increased 60 fold by closing the fuel cycle, the energy potential of uranium reserve will be orders of magnitude higher than other energy sources.
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Potential Nuclear Heat Applications
Nuclear heat ~ 1000°C
•Current generation reactors are capable of delivering heat between 300 and 350°C. This type of heat can be used only for low temp. applications such as desalination and district heating.•In future, Generation IV reactors will operate at significantly higher temperatures, 500-1000°C and will make it possible to use nuclear heat directly in process industries, replacing currently used fossil fuel. This will significantly reduce GHG emissions.
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Generation IV Reactor Conceptsof Generation IV International Forum
Fast550SodiumSodium-Cooled Fast Reactor (SFR)
Thermal or Fast430-625WaterSupercritical Water-Cooled Reactors
Thermal950HeliumVery High-Temperature Gas Reactor (VHTR)
Epithermal700-850Fluoride salts
Molten Salt Reactor (MSR)
Fast550-800Lead-Bismuth
Lead-Cooled Fast Reactor (LFR)
Fast850HeliumGas-Cooled Fast Reactor (GFR)
Neutron Spectrum
Outlet Temp. ºC
CoolantReactor Type
•High outlet temperatures from the Gen IV reactors would allow nuclear heat to be used for process industries where the heat is currently supplied by fossil fuel•Because of the high outlet temperatures, electric power generation efficiencies will be significantly higher – 45-50% range.•Use of thermal energy, without producing electricity will increase the overall thermal efficiency
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Low-Temperature Applications
• Desalination• District Heating
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Water Desalination - Issues• 1/3rd of world’s population (1.7 billion) live in water scare areas –
estimated 2.4 billion by 2025– UN target – By 2015, reduce the population unable to access safe
drinking water to half of that in the year 2000.• 0.08% of the water on earth is accessible for direct human use
– 70% of the planet is covered with water– Fresh water – 2.5% of the total– 70% of the fresh water is frozen in polar ice caps – rest in soil
moistures or deep aquifers• Desalination is a solution – but energy intensive
– 7 – 22 kWh/m3 electrical plus thermal - depending on the process (distillation, RO or combination)
– Natural gas is the most common fuelGHG emissionsAffordability and availability
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Nuclear Water Desalination• Nuclear power – a sustainable source of energy for
desalination– 150 reactor years of experience – Largest desalination plant (80 000 m3/d) coupled with BN350
fast reactor operated until 1999 in Aktau, Kazakhstan for 26 years
– Four plants (1 000 – 2 000 m3/d) in Japan with combined 125 reactor-years
– India building a demonstration plant (6 300 m3/d)• IAEA activities
– International Nuclear Desalination Advisory Group – Collaborative Research Projects on nuclear desalination– Developed a computer code (DEEP) for economic evaluation
• Coupling of desalination plant to nuclear reactor– Avoid cross contamination by radioactivity– Limit the desalination load to a fraction of total power output – Alternate source of energy – in case of nuclear reactor
shutdown
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Nuclear Desalination Projects
Evaporators at Akatu, Kazakhstan Operating plant, Ohi, Japan
Hybrid desalination plant, India
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Water Desalination Challenges and Issues
• Disparity: Nuclear technology, infrastructure not available in many countries that have scare water resources
• Public perception: fear of radioactive contamination
• Socio-environmental aspects: location of nuclear plant, effect on marine environment
References:1. B.M.Misra; Role of nuclear desalination in meeting the potable water needs in water
scarce areas in the next decades, Desalination 166 (2004) 1-92. IAEA website http://www.iaea.org/nucleardesalination
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District Heating• In northern countries, space and water heating represents a
major energy consumption and it is largely supplied by fossil fuel
– In Canada commercial and residential sector account for 30% of energy consumption – 60% of which is for space and water heating
– Using nuclear heat presents opportunity for CO2 reduction• District heating infrastructures exist in some major cities in
Eastern Europe, Russia and FSU republics as well as some major cities in the West – Toronto, Helsinki etc. – supplied by fossil fuel
• The only nuclear powered district heating network is still operating in Refuna district in north central region of Switzerland
– Heat supplied from Beznau power plant – two 350 MWe PWRs– More than 2200 users – 80 MWth load– 31 km primary distribution network– Replaces 12740 tons of heating oil per year– Reduces CO2 emission by 44400 tons per year
• Requires heat at relatively low temperature ~ 80°C
•Apart from commercial and residential sector, there is also a need for space heating in industrial sectors. In Canada, greenhouses are extensively used for growing vegetables. Bruce A nuclear power station provides heat to a number of agribusinesses located in the energy park.
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District Heating• Issues, challenges
– Locating new nuclear plants near urban areas– Public perception – final product is delivered to
consumers directlyPreventing radioactive contaminationIntermediate heat transfer equipment
– Economics Cost competitive with current methodsConsider modular reactorsCombined Heat and Power (CHP)
– Seasonal demand – only in winter– Coupling – load following, outages of nuclear plant,
effects of transients, coupled dynamics of electricity production
References •Generation IV Roadmap Crosscutting Energy Products R&D Scope Report, Issued by the Nuclear Energy Research Advisory Committee and the Generation IV International Forum, December 2002•Non-Electric Applications of Nuclear Energy, IAEA-TECDOC-923, (Proceedings of an Advisory Group Meeting Held in Jakarta, Indonesia, 21-23 November 1995), IAEA, Vienna, January 1997.
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High-Temperature Applications
• Hydrogen Production through “water-splitting”
• Heat for process industries
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Hydrogen Demand and Supply• Current hydrogen production
World ~ 45 million t/aUS ~ 9-11 million t/aCanada ~ 3 million t/a
• Hydrogen used for chemical production is mixed with other gases
Ammonia – Hydrogen + NitrogenMethanol – Hydrogen + Carbon monoxide
• World DemandHydrogen - the “energy carrier” for the futureHydrogen has potential to replace fossil fuel and significantly reduce GHG emissionsDemand is expected to grow in both industrial and transportation sectors
• Upgrading of bitumen is a major use for hydrogen in Canada
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Hydrogen Demand - Transportation Sector• There is a strong incentive for alternative fuel for vehicles as the
oil production and prices peak• Hydrogen Fuel Cell Vehicles (FCV) - several challenges
– Performance improvement– Cost reduction – affordability – Infrastructure – for hydrogen storage and transport– Codes and standards – safety – public perception
• Plug-In Hybrid Vehicles (PHEV) are being considered as an alternative for near-term deployment
• Uncertain if FCV or PHEV will dominate in the medium and/or long-term – affects hydrogen demand
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Global Hydrogen Demand
• Global Energy Technology Strategy Program (GTSP) predictions are based on successful deployment hydrogen systems and 550 ppm CO2 climate policy
• Hydrogen deployment through 2035 is predicted to be in stationary applications – buildings and industry
• Hydrogen deployment in transportation sector is expected to increase only beyond 2050.
1. Reference: Global Energy Technology Strategy – Addressing Climate Change, Phase 2 Findings From An International Public-Private Sponsored Research Program, Global Energy Technology Strategy Program (GTSP), May 2007 –Authors – J.A. Edmunds, M.A. Wise, J.J. Dooley, S.H. Kim, S.J. Smith, P.J. Runci, L.E. Clarke, E.L. Malone and G.M. Stokes.
2. 1 EJ = 1 X 1018 J = 8.3 million tons of hydrogen
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Hydrogen Use in Canada
Hydrogen Systems Project Team, Feb, 2005
Reference: Hydrogen Systems : A Canadian Strategy for Greenhouse Gas Reduction and Economic Growth, Prepared by Hydrogen Systems Project Team, February 16, 2005
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Hydrogen for Oil Sands
• Hydrogen is used for upgradingPrimary upgrading – hydro-conversionSecondary upgrading –hydro-treating (removes S, N)
• Hydrogen consumption depends on the extent of upgrading 2.5 kg/b for normal synthetic crude - 38°API4.3 kg/b for higher quality crude - 40°APICost of hydrogen Vs value added determines the upgrading
• Hydrogen is produced on site – mostly by steam reforming of natural gas (SMR)
• Growing trend towards Partial Oxidation (POx) of coke (bitumen residue).
•Bitumen produced from Athabasca oil sands is converted to synthetic petroleum crude – through a process called upgrading which consists of increasinghydrogen/carbon ratio in the crude by addition of hydrogen•The extent of upgrading depends on the target quality of synthetic crude. Higher quality crude has higher price.•When the petroleum crude prices were low (~$40-50/b) greater hydrogen consumption was not economically justified. With the current high prices of crude (>$100/b), hydrogen demand for upgrading has gone up.•Because of increasing natural gas prices, there is a growing trend towards using bitumen residue as feedstock for hydrogen – but it produces significantly higher GHG emissions.
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Hydrogen Demand for Oil Sands
11.03.64500
1.70.56700
Hydrogen demand,kt/d
Million t/yMillion scf/d
3.30.7Synthetic crude oil, million b/d
5.01.2Bitumen production, million b/d
20402005
•With the current high prices of petroleum crude, the economics of producing synthetic crude from oil sands has significantly improved.•Bitumen production is expected to quadruple by 2040 based on the approved and planned projects in Athabasca•Hydrogen demand is expected to increase disproportionately because of increasing trend towards producing higher grade crude with additional upgrading.•These estimates are based on AECL’s internal study.
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Why Nuclear Hydrogen?
• High temperature Gen IV reactors makes it possible to produce hydrogen by “water-splitting” processes
Non-GHG emittingMuch more energy efficient and economical compared to present-day electrolysis
• Internationally, the nuclear hydrogen R&D is being driven by the projected increase in demand for the transport sector.
• In Canada, unique opportunities in oil-sands sector
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Current Production Methods
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Production of Hydrogen
• Theoretical energy required to produce hydrogen– Steam ~ 120 MJ/kg– Methane (natural gas) ~ 20 MJ/kg– Hydrogen Sulfide (found in natural gas in Alberta) ~ 10 MJ/kg
• Current production methods– More than 70% produced by reforming of natural gas – Steam-
Methane Reforming (SMR)– To a lesser extent from other hydrocarbon sources – e.g.
naphtha, petroleum residues (coke), Partial Oxidation processes
– ~ 2% by electrolysis water
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Steam-Methane Reforming
•More than 70% of hydrogen produced by this process •Uses natural gas - ~70% feed, ~30% fuel
•Produces 9.5 tons of CO2 for every ton of hydrogen•Cost ~$1500/ton at natural gas price of $6/GJ (2005) – no CO2sequestration – highly sensitive to natural gas price
C 850 4H CO OH2CH o2224 +→+
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Conventional SMR
2 million scf/d merchant plant1/50th of normal plant SMR
CO2 Absorption Tower
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Partial Oxidation of Hydrocarbons• Oxygen is introduced in the
feed • High-sulfur feed can be used –
but requires gas cleaning unit after HT Shift reactor
• Coke residues from upgrading plant can be used as a feed stock
• Cost competitive with Steam-Methane Reforming at natural gas price > $6/GJ
• Emits 14-16 ton of CO2 per ton of hydrogen
• Main attraction is price stability and secure supply of raw materials
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Electrolysis of Water
The only non-GHG emitting technology
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Conventional Electrolysis
• Not economical for large-scale production of hydrogen– Energy efficiency ~30%
compared with ~80% for SMR
• High equipment cost – Commercial cell capacity ~
5 kg/h– Requires 8 cells for a 1
ton/d plant• Requires cheap electric
power– Could be cost competitive if
produced during “of-peak” power.
•Unlike electricity, hydrogen can be stored. So off-peak capacity of a power plant can be used to produce hydrogen – thus improving the economics of the power plant operation.
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Hydrogen Production Using Nuclear Energy
• Nuclear-assisted steam methane reforming (>800°C)
• Electrolysis of water – conventional and high temperature
• Thermochemical cycles (500-900°C)
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Nuclear Assisted Steam-Methane Reforming
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Use of Nuclear Energy for Steam Methane Reforming
• Most (~ 30-35 Mt/y) of the hydrogen produced in the world is by steam methane reforming (SMR) using natural gas feedstock
• In SMR, Natural gas is also used as fuel• Emits about 9.5 tons of CO2 per ton of hydrogen
– ~ 1/3rd of CO2 from fuel – ~ 2/3rd of CO2 from the process – easy to sequester
• Natural gas fuel can be replaced by thermal energy from high-temp. Gen IV reactor
– Reduces total CO2 production by 1/3rd
– CO2 from the process can be easily sequestered – thus making the process CO2-free
• US DOE and JAEA pursuing the R&D – a novel SMR design is required
• AECL demonstrated a similar concept on a lab scale in 1980s.
2224 4HCOOH2CH +→+
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Integration of SMR with Gen IV High-Temp. Reactor
Source: JAEADemonstration planned for 2008-09
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Electrolysis – Using Nuclear Power
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Effect of Temperature on Energy Required for Electrolysis
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Comparison of Conventional Vs HT Electrolysis
~33%27%Overall efficiency -current nuclear plants
steamLiquid WaterFeed to the cell
~ 80%~ 80%Electrolysis efficiency
1.0-1.2 V2.0-2.1 VCell potential
5 MPa (50 bar)1 MPa (10 bar)Operating pressure
45-55%32-36%Overall efficiency – Gen IV VHTR (900°C)
Ceramic electrolyte (oxygen ion-conducting or proton-conducting ceramic electrolyte
Mostly alkaline solution (but also acidic solutions, PEM)
Electrolyte
~ 850°C<100°COperating temperature
High-Temperature Electrolysis
Conventional Electrolysis
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Status of HT Electrolysis
Being developed under US DOE’s Nuclear Hydrogen Initiative, At Idaho National Lab (INL)
Based on SOFC technology
Unlike SOFC, SOEC development is entirely in nuclear R&D community
Demonstrated at 100 L/h at INL
0.5 kg/h ( ~ 15 kW) integrated test planned to be complete by July 2008
Pilot scale planned for 200 kW
Several challenges – optimization of the cell design, equipments for handling hot (850 °C) hydrogen and oxygen
Parallel developments in Japan and France 25 cell prototype stack
lan to develop 1000 cell stack
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High Temperature Electrolysis Coupled with Gas Cooled Very High Temp. Reactor
• US DOE – New Generation Nuclear Plant (NGNP) project
– Prototype high-temperature helium cooled reactor
– Cogeneration of hydrogen– US $ 4 billion project– Start-up by 2020
• US DOE Nuclear Hydrogen Initiative program
– 2008 - Integrated lab scale demonstration (15 kW)
– 2011 – decision on technology (HTE or TC or both)
– 2013 - Pilot scale 200 kW 600 MWth ReactorHydrogen – 2383 t/d85 million scf/d
References:1. Herring JS, Lessing P., O’Brien JE, Stoots C, Hartvigsen J, Hydrogen production
through high-temperature electrolysis in a solid oxide cell, Second Information Exchange Meeting on Nuclear Hydrogen Production, Argonne National Laoboratory, IL, USA, October 2-3, 2003.
2. Herring JS, Lessing P., O’Brien, JE, Stoots C., Kaufmann, M., High temperature solid-oxide electrolyzer system, DOE Hydrogen Program FY 2004 Progress Report.
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Thermochemical Cycles
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Thermochemical cycles for H2 Production
Water O2
HighTemp.Heat
WasteHeat
H2
ChemicalsCycled
•Water splits spontaneously at very high temperatureH2O → H2 + ½ O2 (> 2500°C)
•Thermochemical cycle splits water at relatively lower temperature (<900°C)
Sulfur-Iodine Cycle
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Thermochemical cycle Efficiencies
Thermal efficiency of the process is important for economics
Higher temp. cycles have better thermal efficiencies
Minimum electrical energy use – maximizes energy efficiencyThermochemical cycles requiring electrical energy for one or more chemical reactions are known as hybrid cyclesTarget efficiencies are in the 40-50% range compared to 25-30% for conventional electrolysisSources of heat (non-GHG emitting) – Gen IV nuclear, Solar thermal, fusion
0
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th =η
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GH
TTT
H
CHthη
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Thermochemical cycles for H2 Production
– Thermochemical cycles have been studied since 1964
– In 2000, US DOE study screened 115 cycles
– Two promising cycles were recommended for further development
Sulfur-Iodine Cycle (General Atomics, USA)UT-3 (University of Tokyo Ca-Br-Fe process)
– US DOE’s Nuclear Hydrogen Initiative selected S-I cycle for demonstration
– Generation IV International Forum (GIF) also selected S-I for development
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References: 1. High Efficiency Generation of Hydrogen Fuels Using Nuclear Power, Annual
Report to the U.S. Department of Energy, August 1, 1999 through July 31, 2000, by L.C. Brown, J.F. Funk and S.K. Showalter, Report No. GA-A23451, July 2000
2. High Efficiency Generation of Hydrogen Fuels Using Nuclear Power, Final Technical Report to the U.S. Department of Energy for the period August 1, 1999 through Sept. 30, 2002, by L.C. Brown, G.E. Besenbruch, R.D. Lentsch, K.R. Shultz, J.F. Funk, P.S. Pickard, A.C. Marshall and S.K. Showalter, Report No. GA-A24285, June 2003
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Desirable Characteristics of Thermochemical Cycle
• Minimum number of chemical reaction steps• Minimum number of separation steps• Minimum number of elements• Employ elements which are abundant• Minimize flow of solids• Minimize use of expensive materials by avoiding corrosive
chemicals• Minimum electrical energy input • Extensively researched - many papers from many authors
and institutions• Tested at a moderate scale• Good efficiency and cost data are available• Temperature compatibility with the nuclear reactor
operating temperature
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Sulfur-Iodine Thermochemical Cycle
SO2 + I2+ 2H2O 2HI +H2SO4
1/2O2 +SO2 + H2O H2SO4
H2 + I2 2HI
Water
O2
H2
Heat
WasteHeat
>800°C
450°C
120°CHI
H2SO4
I2
SO2
•Requires high temperature (>850°C) reactor – e.g. VHTR, MSR•Significant challenges in separation of HI and H2SO4• Various process flow sheets proposed• Efficiency Vs. Cost optimization• Cogeneration can improve efficiency from 42% to 52%
•Low temp. waste heat can be used for desalination
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Current Status of S-I Process
• Endorsed for development by the Generation IV International Forum (GIF)
• GIF Hydrogen Project Plan identified remaining R&D tasks for the participants (Canada, France, Japan, South Korea, EURATOM and USA)
• JAEA has a fully integrated lab scale facility (50 L/h) • KAERI – just completed an integrated lab scale facility• US DOE and French CEA collaborating on a pilot plant
demonstration (5 Nm3/h) at General Atomics facility in San Diego – target commissioning July 2008
• US DOE’s Nuclear Hydrogen Program’s target for pilot plant by 2013
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S-I Cycle Development in JapanH2 Production Rate
Connect to HTTR
Pilot test
Basic engineering Testing Rig(on going)
30l/hr H2produced
Principle proved(1997)
Produce acids Decompose H2SO4
Decompose HI
Basic Engineering Test Rig
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Hybrid Sulfur Thermochemical Cycle
SO2 + 2H2O H2 +H2SO4
1/2O2 +SO2 + H2O H2SO4
Water
O2
H2
Heat
WasteHeat
>800°C
Electrolysis 30-90°C
H2SO4SO2
• Developed by EU Joint Research Center (ISPRA) and Westinghouse• Eliminates use of expensive iodine• Simple two-step process • Challenge is to reduce power consumption and cost of electrolyzers • Less efficient and cost-competitive compared to S-I Cycle •Estimated efficiency 37% to 40%• Selected by GIF as alternative technology
Electrical energy
H2
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Lower-Temperature Thermochemical Cycle
Water
O2
H2
Heat and
Electricity
WasteHeat
(g) 2HCl (s)CuCl*CuOH (s)2CuCl 222 +=+ O
2HCl 2Cu )(H 2CuCl(l) 2 +=+ g
Cuaq 2)(2CuCl (s) 4CuCl 2 +=
)(CuCl* CuOO21 (l) 2CuCl 22 s=+
CuCl
CuCl
35-75°C(electrolysis)
CuCl2
HCl
CuO*CuCl2
Cu
350-400°C
430-475°C
530°C
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Status of Cu-Cl Cycle DevelopmentConcept developed by US DOE (Argonne Nat. Lab)Hybrid cycle - ~40% of energy input is electrical Maximum temp. is 520ºC – compatible with lower temp. Gen IV reactors – SCWR, SFR Initial estimates of efficiency ~ 44% - comparable to S-I cycleChallenges
Solids handling - continuous transfer between stepsElectrolytic vessel is too large
Being investigated by GIF Hydrogen Project as an alternative technologyA consortium of Canadian universities developing all aspects of technology in collaboration with US DOE (ANL)AECL’s focus – on development of electrolytic step
Optimize efficiency – electrode configurationAECL also developing an alternative process to eliminate solid copper handling
References:1. M.A. Rosen, G.F. Naterer, R. Sadhankar and S. Suppiah, Nuclear-Based Hydrogen
Production with a Thermochemical Copper-Chlorine Cycle and Supercritical Water Reactor, in press, International Journal of Energy Research
2. “Generation IV Reactor Development in Canada”, R. Sadhankar, D. Brady, R. Duffey, H. Khartabil and S. Suppiah, 3rd International Symposium on SCWR Design and Technology, Shanghai, March 12-15, 2007.
3. “Future Hydrogen Production Using Nuclear Reactors”, R.R. Sadhankar, J. Li, H. Li, D.K. Ryland and S. Suppiah, Climate Change Technology Conference of the Engineering Institute of Canada, Ottawa, Ontario, 2006 May 9-12.
4. Leveraging Nuclear Research to Support Hydrogen Economy, R.R. Sadhankar, International Journal of Energy Research, Vol. 31, 1131-1141, May 2007.
5. Lewis MA, Serban M, Basco J, Hydrogen Production at <550°C Using Low Temperature Thermochemical Cycle., ANS/ENS International Meeting, New Orleans, LA, 16-18 Nov. 2003.
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Modified Cu-Cl Thermochemical Cycle
Water
O2
H2
Heat and
Electricity
WasteHeat
(g) 2HCl (s)CuCl*CuOH (s)2CuCl 222 +=+ O
(g)HCuCl)(HCl2CuCl 22 +=+ aq
)(CuCl* CuOO21 (l) 2CuCl 22 s=+
CuCl
(electrolysis)
CuCl2
CuO*CuCl2350-400°C
<100°C
530°C
• Eliminates solid copper handling• Development and optimization of electrolysis equipment is a challenge • Initial work by AECL shows promise
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Efficiency of Hydrogen Production Using Nuclear Electricity and Heat
Water-Splitting “carbon-free” Processes
70-8040-6045-5532-36Efficiency coupled with high-temperature Generation IV reactors, %
Not feasibleNot feasible3327Efficiency coupled with present generation nuclear reactors, %
70-80>4585-9075-80Efficiency of chemical process, %
~800530-850~80070-80Temperature Required, °C
Steam-Methane ReformingThermochemical
Water SplittingHigh-Temperature Electrolysis
Conventional Electrolysis
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Cost of Nuclear Hydrogen
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Cost of Nuclear Hydrogen
• Base-line costs (Source – International Nuclear Societies Council, 2004):– SMR - $1552/t ( for 50 t/day production, natural gas @ $
6.67/GJ)– Electrolysis - $ 2414 – 2712 /t (for 1 ton/day, $46-56/MWh)
• Nuclear Hydrogen costs– Sulfur-Iodine thermochemical (US DOE, 2007) $ 2200/t– Hybrid sulfur process (Westinghouse, 2005) - $2,400/t– High-temp. electrolysis (US DOE, 2007) $2,530/t
• Both thermochemical and high-temp. electrolysis are evolving technologies – cost cannot be estimated realistically
References:1. A.I. Miller, Hydrogen Economics for Automotive Use, Chapter 6 in Nuclear
Production of Hydrogen – Technologies and Perspectives for Global Deployment, International Nuclear Societies Council, 2004
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Cost Comparison
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Solar-PV
Nuclear -
electrolys
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Therm
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H2 C
ost,
$/kg
HighLow
Ca rb o n W a te r
Source: IEA Committee on Energy R&D, Hydrogen Co-ordination Group, June 2004
•Reference: Hydrogen Coordination Group, Committee on EWNERGY Research and Development, International Energy Agency, Organisation for Economic Co-operation and Development, Policy Analysis IEA/CERT/HCG(204)3, June 2004•The costs for hydrogen production from natural gas ad coal include the cost of CO2capture and storage.•Hydrogen production from on-shore wind, off-shore wind, solar thermal and solar PV power sources is assumed to be by electrolysis of water.
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Evolution of Cost Over Time
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Safety Considerations
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Nuclear Safety
• No historical precedent of co-location of hydrogen plant and nuclear reactor.
• Licensing challenges for first-of-a-kind • Regulators must be convinced that hydrogen plant does not pose
statistically significant hazard for nuclear reactor
Leave nothing to chance.-GNF
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Safety Considerations
• Quantitative Risk Analysis (also known as Probabilistic Safety Analysis) required
• Hazards due to hydrogen plant and heat transfer loopHydrogen ExplosionsChemical fires (H2, O2 and other reactive chemicals)Chemical releases (toxic, corrosive gasses and liquids)
• Radioactive contamination of hydrogen plantMigration of radioactive tritium through intermediate heat exchanger
• DOE estimated minimum distance based on 100 kg hydrogen explosion to reduce the probability of nuclear core damage to 1 in 1 million.
110 m 60 m with blast deflection barriers, earthen wall or below-grade nuclear plant
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Proposed Arrangement of Nuclear and Hydrogen Plants
References:1. Steven R. Sherman, Nuclear Plant /Hydrogen Plant Safety: Issues and Approaches,
ST-NH2 Conference, American Nuclear Society Meeting, Boston, June 24-28, 20072. Hyung Seok Kang et al. Regulatory Issues on the Safety Distance due to Gas
Explosion and an Overpressure Prediction by Correlation for the JAEA Explosion Test in an Open Space, ST-NH2 Conference, American Nuclear Society Meeting, Boston, June 24-28, 2007
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Hydrocarbon Fuels from Nuclear Hydrogen
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Hydrocarbon Fuels for Transportation
Nuclear PowerPlant
Hydrogen Plant
Coal Power Plant
Synfuel Plant
Separator
Water
WaterFlue Gas
CO2O2
H2
Coal
Electric Power
Heat +Electricity
Transportation Fuels
References:1. Ken Shultz, S. Locke Bogart, Richard P. Noceti, Synthesis of Hydrocarbon Fuels
Using Renewable and Nuclear Energy, ST-NH2 Conference, American Nuclear Society Meeting, Boston, June 24-28, 2007
2. B.D. Middleton and M.S. Kazimi, Nuclear Hydrogen and Captured Carbon Dioxide For Alternative Liquid Fuels, ST-NH2 Conference, American Nuclear Society Meting, Boston, June 24-28, 2007
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Nuclear Hydrogen + Captured CO2 – an Alternative Route to Hydrogen Economy
• Motivations– Technologies for CO2 capture and making synthetic fuels from
hydrogen and CO2 are available– Does not require large infrastructure changes to transportation sector
to achieve the same CO2 reduction
• Current CO2 emission in USA – Total 5900 million t/y– Thermal power plants ~ 1894 million t/y– Transportation section ~ 1891 million t/y
• Converting all CO2 from thermal power plants to synthetic fuel
– Reduces CO2 emissions by ~ 1/3rd
– Requires 255 million t/y of hydrogen (25 times the current demand)215 GWth (~ 105 GWe) Gen IV nuclear capacity150 to 300 new nuclear plants depending on individual plant capacities
– Replaces ~75% of gasoline
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High-Temperature Process Heat Applications
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Petroleum Refining
• Processes requiring large amount of thermal energy are potential candidates for Gen IV reactors
– Oil refineries– Petrochemical plants– Aluminium production
• A petroleum refinery requires about 500 MW of thermal energy – most of which at or below 540°C
• Major challenge is integration of process plant with a nuclear reactor
453
200-500112Steam Generation
20-603Effluent Water Cleaning
820-8505Hydrogen generation
430-54053Gasoline Reformer
340-38512Gasoline Desulphurisation
340-38515Middle Dist. Desulphurisation
340-38517Vacuum Gas Oil Desulphurisation
340-38520Vacuum Residue Distillation
50-8053Propane Deasphalting
230-38546Vacuum Distillation
230-370117Crude Oil Distillation
Temp, °C
Heat (MW)
ProcessThermal Power demand of 6 million t/y refinery
•Gen IV high temperature reactors could be used to provide thermal energy for process industries.• Combined heat and power applications (CHP) improve the overall energy efficiency.•Ref: Generation IV Roadmap – Crosscutting Energy Products R&D Scope Report issued by the Nuclear Energy Advisory Committee and the Generation IV International Forum, Report No. GIF-008-00
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Extraction of Bitumen from Deep Oil Sands Depositsof Gen IV Systems
•Steam Assisted Gravity Drainage (SAGD) – for deep deposits •Steam Requirements
•2.5 – 4.0 barrels of steam/barrel of oil•6-12 MPa, 275-320°C steam
• Challenges •Distance for steam travel•Fracture pressure of formation
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Conclusions• Use of nuclear thermal energy directly has tremendous potential
to replace fossil fuel and reduce GH-emissions• Current generation reactors can possibly be used for low-temp.
applications– Desalination, district heating– Challenges – dynamics of co-generation, public perception
• Hydrogen demand will grow rapidly– Demand from industry (oil refining, upgrading) is expected to peak
earlier – Demand from transportation sector is expected to dominate beyond
2050 – several challenges remain in the deployment of hydrogen as “energy carrier”
• Non-GHG emitting H2 production technologies required for the future
– Conventional electrolysis using “off-peak” power may be deployed in the interim
– Thermochemical cycles and high-temperature electrolysis need further development and demonstration but are important
– Coupling technologies and safety issues are equally important
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Topics for Discussion• Low Temperature Applications
– Potential to reduce greenhouse gas emissions– Technical challenges of deployment of nuclear reactors for
Combined Heat and Power (CHP) applications – load following, disruption of service due to outage of nuclear reactors, avoiding radioactive contamination, seasonal load for district heating
– Public perception – final product (potable water and heating) directly delivered to the customer, location of nuclear plants near urbanareas
– Adequacy of current generation and Gen III (1000-1500 MW) reactors for moderately low load applications for desalination and district heating
– Need to develop modular reactors (100MW?) for these applications– Disparity – availability of technology and nuclear infrastructure in
countries that need desalination– Economics – consumer affordability
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Topics for Discussion
• Hydrogen Production– Factors affecting growth in hydrogen demand: stationary fuel cell
applications, industrial applications – ammonia, methanol, oil upgrading etc., fuel cell vehicles, parallel development of plug-in hybrid vehicles
– Challenges of hydrogen as an “energy carrier”- storage, distribution, infrastructure, fuel cell costs and performance, safety codes and standards
– Factors favouring use of nuclear power for hydrogen: GHG reduction, energy efficiency at high temperatures, volatility ofnatural gas prices
– Technological challenges for deployment of high-temperature electrolysis and thermochemical cycles: developed on bench-scale, high costs of development and demonstration on large scale, integration (coupling) with nuclear plant, safety
– Can the “water-electrolysis” be deployed with the current nuclear reactors in the interim?
– Cost competitiveness of nuclear hydrogen
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