1. Possibility of Active Carbon Recycle Energy System
Yukitaka KATO
Research Laboratory for Nuclear Reactors,
Center for Research into Innovative Nuclear Energy Systems (CRINES),
Tokyo Institute of Technology
16 April, 2009
11:30-11:50 Session 5; Economics and Market Analysis of Hydrogen Production and Use (Invited presentation)
Fourth NEA Information Exchange Meeting on Nuclear Production of Hydrogen
13-16 April 2009, Oakbrook, IL, USA

2. Contents Carbon Supply Security
Carbon Balance of Japan
Carbon vision for future
Proposal of Active Carbon Recycle Energy System, ACRES
ACRES with Methane
ACRES with Carbon Monoxide
ACRES in Steel Making
Conclusion

3. Energy Balance of Japan, depending on Imported Carbon
Primary Energy
Total　23.1x1018 J
Import　83.4% (Almost fossil fuels)
Domestic 16.6%
(Nuclear 11.4%, Renewable 4.4%, Fossil fuels 0.8％）
Energy Consumption
Waste heat (anergy)　26.8%
Utilization　69.5%
Public 21.5%
Transportation 16.8%
Industry 31.2%
Electricity 36% (Nuclear sharing 40% )
Heat 55% (Frontier of Nuclear)
Plastics, 9.1%
Carbon resources, 84%
Carbon resources covers 84% of all energy sources, and is almost imported.
Carbon resources is used only 9.1% for plastic materials.
Carbon resources over 90% is used for just heat source fuels.
Plastics, 9.1%
Energy balance and flow in Japan (2004)
Fig , Energy White Paper of Japan, METI, Japan, 2006

4. Carbon Supply Security
Excess of CO2 emission
Carbon consumption and CO2 emission enhance energy resource depletion and global warming.
Carbon resources of over 90% is used for just fuels.
Shortage of carbon supply
Japan imports all of carbon resources, hardly depends on overseas.
Carbon supply security of country is vulnerable. Difficulty of industrial development in the country remains by unreliability of resource supply security.
Establishment of carbon supply security is crucible for a country development.

5. Carbon vision for future
Conservation of carbon consumption, recycle use of carbon
Evolution of relationship between carbon and production industry
Stop of carbon once-through use
Recycle use of carbon
Use of nuclear power for the primary energy source for Carbon Recycle
Zero CO2 emission
Sufficient amounts to ensure the country energy demand
Establishment of carbon recycle energy system

6. Proposal of Active Carbon Recycle Energy System, ACRES

7. Subjects: Hydrogen as an energy carrier
Evolution of energy conversion
For Industrial revolution in 20th C
Phase change of water → Electricity production
For mobile use
Water decomposition and regeneration → Hydrogen production
H2: Difficulty of storage and transportation, Risk of explosion, Complex electricity production system　
H2O(v)
H2 + O2
Work, W
Excess compression work for storage
Risk of explosion
Complex power conversion
Energy, E E W
H2O(l)
H2O
Water phase change
Water decomposition / oxidation
Water
Hydrogen
Conventional energy conversion

8. Proposal: Carbon as an energy carrier
Carbon recycle: Usage of carbon as an energy carrier
Ease for storage and transportation
Co-use of carbon for sources of heat and material
Adaptability to conventional infrastructures and retail usages
CxHyOz + O2
Active Carbon Recycle Energy System, ACRES E W
Material
CO2 + H2O
CO2 reduction/oxidation
Carbon dioxide
Proposed ACRES

9. Three Processes for ACRES
Recovery and separation
Recov./Sep. energy
Effluent CO2
Separated CO2
Regen. energy
Usage
Materials
Regeneration
Energy
Hydro carbon
Carbon flow
Input E > output E
Fig. Three processes for Carbon Recycle

10. ACRES with methane

11. Structure of ACRES with methane
Recovery and separation
Physical and chemical sorptions
Recov./Sep. energy
Effluent CO2
Separated CO2
Regen. energy
Usage
4H2O
4H2O
Regeneration
Materials
Water decomposition：　4H2O→4H2+2O2
Methanation：　CO2+4H2 →　CH4+2H2O
Energy
CH4
Combustion E: CH4+2O2 → CO2+4H2O
Hydrogen E: CH4+H2O → 4H2+CO2
Materials:　xCH4 →　（-CH2-）x + x/2H2
Fig. Methane recycle system

12. Enthalpy balance of ACRES with metahne
CO2+4H2, +2O2
-165
Thermally reversible
Metanation
CH4+2H2O, +2O2
Reforming, Waste heat recovery
Electricity H2
ＣＨ4
Work/heat
+967
Water decomposition
CO2
-802
Combustion energy
Oxidation
CO2+4H2O(g)
[HHV-kJ/mol-CO2]
Recycle ratio = Output heat/input electricity = 82.9%
Fig. Enthalpy balance of Methane carbon recycle energy system based on water electrolysis
Enthalpy loss for methane conversion/recycle is less 20%

13. ACRES with carbon monoxide

14. Structure of ACRES with Carbon Monoxide
CO is active and useable resource for energy and material usages
Recovery and separation
Physical and chemical sorptions
Recov./Sep. energy
Effluent CO2
Separated CO2
Regen. energy
Usage
H2O
Regeneration
Materials CO
CO2 electrolysis: CO2→CO+1/2O2 　
Water electrolysis: H2O→H2+1/2O2
Methanation: CO2+H2→CO+H2O
Energy
H2O+1/2O2
Combustion/Reduction E : CO+1/2O2 → CO2
Hydrogen E : CO+H2O→H2+CO2
Materials: xCO+yH2 +zO2→ CxHyOz
Fig. Carbon monoxide recycle system

15. Fig. Enthalpy balance of CO2/CO recycle energy system
Enthalpy balance of ACRES wit CO -Co-use of electricity and heat for CO regeneration-
Thermally regenerative
CO+H2O, +1/2O2
+41
　CO has higher energy density than H2
Enthalpy loss from H2 to CO is nothing.
CO2+H2, +1/2O2
CO production
Work/Heat/Reductant
Electricity
+242
-283
Oxidation
Water decomposition
Recycle ratio = Output heat/input electricity = 103%
CO2+H2O(g)
[HHV-kJ/mol-CO2]
Fig. Enthalpy balance of CO2/CO recycle energy system

16. Development of ACRES Developments of carbon recycle processes
Selection of recycle media
Technology for CO2 recovery
Tech. for hydrocarbon regeneration
Innovative nuclear reactor having high-fuel efficiency and breeding ability
Development of market of carbon recycle
Showing the benefits of recycle use
Application on carbon-use industries
Expansion of market of carbon recycle use
Synergy between nuclear power and industries.

17. INES-3, Nov., 2010, Tokyo
Welcome to,
The Third International Meeting on Innovative Nuclear Energy Systems, INES-3
-Contribution of Nuclear Power on a Low Carbon Society-
31st October – 3rd November, 2010, Tokyo
Organized by CRINES (Center for Research into Innovative Nuclear Energy Systems), Tokyo Tech
URL:

18. Thank you! yukitaka@nr.titech.ac.jp
Tokyo Tech Global-COE Program, “Multidisciplinary Education and Research Center for Energy Science”