The 2nd Joint Qatar – Japan Environmental Symposium, QP - JCCP
The 21st Joint GCC – Japan Environmental Symposium 5th– 6th February 2013
Tackling Challenges to Sustainable Energy
and Environment
Takashi Tatsumi
Executive Vice-president for Research
Tokyo Institute of Technology
ü Energy is crucially important as causative factor in economic development.
ü The expanded supply and use of energy are raising difficult global issues concerning climate changes and environmental protection.
ü To cope with these issues, the present energy system needs fundamental changes.
ü There is a close relationship between energy use per capita and GDP per capita.
The present energy system needs fundamental changes
Close relationship between energy use per capita and GDP per capita in different countries (Source: data in the 2006 Key World Energy Statistics from IEA, Author: Frank van Mierlo).
There is a substantial deviation from the linear correlation between energy consumption and GDP per capita, which reflects (1) the adoption of increasingly more efficient technologies
for energy production and utilization, (2) changes in the composition of economic activity, (3) attitudes and policies toward energy saving, etc.
We definitely need to decouple GDP growth from energy growth. To aim for this, we need to develop and introduce more energy-saving processes, devices, and solutions.
Decoupling GDP growth from energy growth required
Energy fluxes from primary energy sources to utilizations (in quads equal to 1.093 x 1018 J) for year 2010 in USA
(Source: adapted from Lawrence Livermore National Laboratory)
57%
Was
te
43%
Use
d
We must reduce the waste energy ü Fossil fuels are the primary energy source and non-fossil fuels
sources, including nuclear energy, accounts for only 16.8% of the total energy use.
ü Only about 43% of the primary energy is used for energy services while the rest is rejected (waste) energy typically in the form of low temperature waste heat.
ü For electricity generation, only 32% (12.71/39.49) of the input energy is transformed into electric energy and in transportation, only 25% (6.86/27.45) of the input energy is used.
ü Thus it is strongly suggested that our major effort to be directed toward sustainable energy and a reduction of greenhouse gases (GHGs) emissions is to reduce the amount of waste energy.
How to attain the target level of CO2 in the climate change mitigation scenario?
ü New advanced materials will particularly spur the development of
processes and materials in the area of energy conversion, energy storage and transport, and efficient energy use.
ü According to the IEA estimation, the CO2 stratospheric concentration must be limited to 450 ppm in order to mitigate the climate change.
ü Although the major contribution toward reducing CO2 emissions should be made by increasing energy efficiency, the target level of CO2 cannot be reached without the substantial contribution of renewables, nuclear energy, and carbon capture and storage (CCS).
Future Sustainable Energy Scenario
ü However, even in the 450 ppm scenario, the contribution of fossil fuels will remain dominant and almost unchanged in terms of total energy consumption.
ü So the use of renewable energies should compensate for the increase in the energy consumption owing to an increased portion of world population that obtain access to a higher energy consumption per capita.
ü We need to develop methods of alternative energy
generation in consideration of these aspects to make an appropriate choice between several alternatives.
Resource
Energy carrier Electricity Heat Mechanical
energy Liquid
Fuel Biomass + + + Hydro + + + Ocean + + + Solar + + + Geothermal + + Wind + +
Possible Energy Carrier for Renewable Energy Sources
ü Liquid fuels can be directly produced only from biomass.
ü Majority (43%) of the world energy final consumption is associated with liquid fuels, while only 17% is accounted for by electric energy.
A fast transition to energy carrier other than the liquid fuels is not expected, particularly in the transportation sector, because: ü The electricity cannot be efficiently stored. So the growing
tendency in transportation is toward hybrid vehicles rather than full electrical ones.
ü Airplanes and trucks can use only liquid fuels. ü The alternative possibility is to install fuel cells to use H2 as
energy carrier. However, this is in rather deep distress due to problems such as storage of H2 on board, cost of fuel cell production and limited lifetime, etc.
ü Liquid biofules can be integrated into the existing energy infrastructure.
The Importance of Liquid Fuels
How to store and transport the solar energy? ü Solar energy will be the future dominating renewable energy:
If the irradiation on only 1% of the Earth’s surface is converted into electric energy at 10% efficiency, a resource base of 105 TW would be provided, which is 10 times as much as the estimated world energy increase by year 2050.
ü Solar energy might be utilized for producing H2 through electrolysis of water. H2 is ideally clean. However, the low energy density of H2 per volume is a serious issue.
ü How about utilizing solar H2 to produce liquid fuels? Then we don’t need to develop a new energy infrastructure.
ArpChem Project Structure
Government-Sponsored Project for Artificial Photosynthesis of Chemicals (ArpChem)
Photocatalytic Production of
Solar H2
INPEX Fuji Film
Mitsui Chemical Mitsubishi Chemical
Project Leader: Takashi Tatsumi Tokyo Institute of Technology
2012-2021 FY (10 years Proj.) 16 MUSD for 2012
Membrane Separation of
H2 from O2
Mitsubishi Chemical JFCC
Catalytic Production of Light Olefins
from CO2 and H2
Mitsubishi Chemical Sumitomo Chemical
University of Tokyo Kyoto University
Tokyo Univ. of Science
Nagoya Institute of Technology
Yamaguchi University
Tokyo Institute of Technology
Toyamai University
How to store and transport the solar energy? ü CO2 can be reduced to liquid fuels as well as chemicals. Of
course, the conversion of CO2 needs non-fossil renewable H2. ü H2 can be directly produced by photocatalytic splitting of water as well as electrolysis of water by solar electricity. CO2 + H2 CO + H2O (Reverse Water Gas Shift Reaction) CO + H2 Hydrocarbons (Fischer-Tropsch Synthesis) or CO + H2 CH3OH (Methanol Synthesis) n CH3OH (CH2)n + n H2O (MTG or MTO on zeolites)
Prof. Domen
Introduction of fuels derived from renewable resources is necessary
ü Biomass conversion will be the preferable mid-term
option to produce liquid fuels.
ü The introduction of more energy-efficient devices in the transportation sector will not compensate for the rapid expansion on the use of liquid fuels owing to the worldwide increase in the number of vehicles.
ü Therefore, the reduction in the CO2 emissions of transportation for the near future will depend mainly on the introduction of fuels derived from renewable resources such as biomass.
Generations of Biomass
First generation Bioalcohols (bioethanol, biobutanol and biopropanol), Biodiesel Second generation Those mainly produced from cellulose, hemicellulose, or lignin through advanced thermochemical, biochemical or catalytic routes. Third generation e.g., Algal oil Fourth generation Isobutanol adopting non-natural metabolic engineering approach.
The Problems with Biomass ü High cost at least in the near future except for few special
cases like bioethanol from sugarcane in Brazil. So biofuel growth will greatly depend on the government subsidies.
ü The alternative is to produce fuels from natural gas (GTL) or coal (CTL), which could be currently also more expensive than fuels from oil.
ü The life-cycle assessment (LCA) suggests that the contribution of biofuels to the reduction of CO2 emissions is small, close to neutral, or even negative, depending on conditions.
Carbon neutrality of biomass ethanol Raw
material Location Output/Input
energy ratio CO2
emission/% Source
Sugar cane
Brazil 7 〜 8 -85 〜 -87% Macedo 2003+
Corn USA 0.77 +30% Pimentel 2003
Corn USA 0.99 +1%+ USDA 2002
Corn USA 1.3 -23% Misono 2010
Beat UK 2.0 -50% Misono 2010
LCA of GHG for Production of Ethanol from Sugarcane in Thailand (Dr. Sagisaka, AIST, Japan)
GHG emission g-GHG/MJ
Fertilizer & Agrochem. Cultivator Fuel Ethanol Production
Transport Dehydration
Gasoline: 70-GHG/MJ
A General View on Biofuel
The assessment of the real impact of the use of biofuel on CO2 (or GHG) emissions is still a matter of debate. Substantial benefits could be questioned also from the point of the supply amount. Therefore, biofuels should be considered as a transitional solution and preferable pathways must be taken accordingly. On the other hand, the possibility of using biomass wastes could offer double benefits of reducing their environmental impact and an efficient valorization of abandoned resources. Close integration and proper balance with production of food and raw materials must be attained to bring benefits to local agriculture, land preservation, employment creation and rural quality of life.
Improvement in the sustainability and efficiency of the production, storage and use of energy required
The following key technological areas require a better design of materials and structures to attain high levels of performance. (1) Reversible chemical to electric energy conversion such as
advanced fuel cells and electrolysis, (2) Solar to electric energy conversion such as third-generation photovoltanic cells, water photoelectrolysis, water photochemical splitting, and photoelectrochemical devices, (3) Thermal to electric energy conversion, namely thermoelectric devices that can utilize solar and low-grade waste heat, (4) Electrical energy storage such as advanced secondary batteries and supercapacitors.
FUTUREーPV Innovation Project FUkushima Top-level United center for Renewable Energy research -Photo Voltaics Innovation
u Reconstruction Agency, MEXT and METI Project aiming to establish top-level united center for renewable energy research in Fukushima, focusing on technological development and practical use of high efficient solar cells.
Research target: “Si Nano-Wire Solar Cells” To improve the conversion efficiency of silicon solar cell to more than 30% by combining bandgap engineered nano-wire solar cells and high efficiency Si heterojunction solar cells as a tandem system
Research Director Prof. Makoto Konagai, Tokyo Institute of Technology
Conclusions ü Fossil fuels and infrastructure for them will be the dominant
factor in the future energy scenario.
ü However, it is necessary to accelerate the transition to renewable energy due to GHG emissions, energy security, etc.
ü To decrease the stratopheric CO2 concentration to acceptable levels, increase in the energy efficiency has the dominant role.
ü For a short term, energy saving, storage or reuse of CO2 together with nuclear and biomass energy will be the strategy to be adopted.
ü On the long-term perspective, the solar energy will become the major source of renewable energy.
Thank you for your attention! ありがとうございました
شكراShukran シュクラン!