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!