Japanese Challenge to Create a Low Carbon Society Clean Coal Technologies, Now and Future

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1 Japanese Challenge to Create a Low Carbon Society Clean Coal Technologies, Now and Future Yoshihiko Nakagaki Chairman of the Japan Coal Energy Center (JCOAL) Advisor to Electric Power Development Co., Ltd. (J-POWER) Minoru Yoshida Director, General Manager of Planning and Coordination Dept., Japan Coal Energy Center (JCOAL) Yoshikazu Noguchi Director of Business Planning Dept., Electric Power Development Co., Ltd. (J-POWER) Introduction Under the increase of world energy demand especially in major developing countries, coal is expected to account almost 30% in the future. Also energy demand will not be satisfied without coal. However, it is true that 30% of carbon dioxide emission is from coal-fired power stations, and there is no other effective solution than abating these emissions. The key is Clean Coal Technologies (CCT), to make power stations to low carbon. It is necessary to develop and transfer these CCTs together with developed and developing countries. Japan, who has excellent CCTs, should play an important role to develop higher innovative technologies and is challenging to make a low carbon society in the world. 1. Coal s advantages as an energy resource and the world energy situation Coal resources have three major advantages. Firstly, they exist in abundance. According to BP estimates in 2009, the reserves-to-production ratio is significantly longer for coal (122 years) compared to oil (42 years) and natural gas (60 years). Secondly, resources are widely distributed around the world, reducing geopolitical risks. And thirdly, coal fuel prices are comparatively low and stable, making coal a highly economical energy resource. Another important factor to consider is that coal acts as a brake against fuel price increases through its competition with other fossil fuels subject to high price volatility, i.e., oil and natural gas. Coal is thus an outstanding energy resource from the point of view of stable supply. Due to these advantages, coal plays an important role in the world s primary energy and electric power markets. In the reference scenario of the IEA s World Energy Outlook 2009 (WEO 2009), world primary energy supply and demand are projected to increase some 40% from 2007 to Over the same period, coal s share is estimated to increase from around 27% to about 29%, with the increases being particularly marked in emerging economies such as China and India. In the electric power sector, coal s share is the largest. Figure 1 shows breakdowns of power generation by energy source in several major economies in Approximately 42% of world 1

2 electricity was generated by coal-fired power plants, and coal s share was particularly high in China (81%), India (68%), and the United States (49%), all of which are heavy energy consumers. Even Denmark and Germany, where uptake of renewables is more advanced, are dependent on coal for around 50% of their output, reflecting coal s role as a core power source underpinning power generation using renewable resources that are subject to vagaries of supply, such as wind and solar power. According to the IEA s reference scenario forecasts in WEO 2009, electricity demand will grow approximately 74% and demand for coal power by approximately 86% by 2030, resulting in coal s share rising from 42% in 2007 to 44% in Growth will be conspicuous in China and India, and developed countries such as the U.S. and Germany, are planning to build considerable new coal-fired capacity. While coal as a fuel is a major source of CO 2 emissions, its advantages make it likely that it will continue to be used by countries around the world. Coal-fired power plants therefore have to be made cleaner. Figure 1 Power generation by energy source in major countries (2007) 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% China 81% 1% 2% 15% 0% India 68% 5% 8% 2% 16% 2% 0% U.S. 49% 2% 21% 19% 6% 1% 2% Japan 28% 14% 26% 24% 7% 0% 2% EU 31% 3% 22% 28% 9% 3% 3% Germany 49% 1% 12% 22% 4% 5% 6% Denmark 47% 4% 22% 0% 9% 18% World total 42% 6% 21% 14% 16% 1% 1% Coal Oil Gas Nuclear Hydro Biomass + Waste Wind Other renewables Sources: IEA Electricity Information 2008 for Germany and Denmark; IEA World Energy Outlook 2009 for other economies. 2. World CO 2 emissions from coal-fired power plants Figure 2 shows CO 2 emissions from coal-fired power plants in the world. In 2007, approximately 8.7 billion tons (around 30%) of the world s CO 2 emissions came from coal-fired power plants. Of this, CO 2 emissions from coal-fired power plants in three countries China, India, 2

3 and the U.S. accounted for approximately 20% of the world total. According to the IEA s WEO 2009 reference scenario, coal-fired power plants will account for approximately 13.9 billion tons (34%) of world CO 2 emissions in 2030, of which China, India, and the U.S. will together account for almost one quarter (24%). Reflecting substantial growth in energy consumption in China and India, coal power in these two countries alone will account for approximately 20% of world emissions. Reducing CO 2 emissions from coal-fired power plants, particularly in China, India, and the U.S., thus holds the key to reducing CO 2 emissions of the world as a whole. For reference, it may be noted that Japan s CO 2 emissions from coal-fired power plants accounted for approximately 1% of the world total in 2007, and this figure is projected to shrink to 0.6% by Figure 2 CO2 emissions (Gt) Carbon emissions from coal-fired power plants in Japan, U.S., China, and India Other Coal-fired power plants in other countries Coal power in Japan Coal power in India Coal power in U.S. Coal power in China China, U.S., and India Source: IEA World Energy Outlook Coal power situation in Japan Figure 3 shows trends in power output in Japan since Early in the 1970s, Japan was heavily dependent on oil-fired power generation. Following twice oil crises during that decade, however, reducing dependence on oil in an effort to stabilize energy supplies was adopted as a base of the national energy policy. More specifically, development of nuclear power, coal power, and natural gas (LNG) was pursued in order to create substitute sources of power to oil. Regarding coal power, J-POWER s Matsushima Thermal Power Plant entered service in 1981 as Japan s first large capacity power plant fueled by coal imported from overseas, prompting the development of many coal-fired power plants using imported coal. 3

4 Figure 3 Trends in power output of general electricity utilities in Japan New energies 0.6% Nuclear 30.6% Geothermal heat 0.3% Oil 7.9% LNG 26.0% Coal 24.7% Hydro 9.1% Source: Agency for Natural Resources and Energy, Overview of Development of Power Sources Trends in power generation efficiency of coal-fired power plants Figure 4 shows trends in the design thermal efficiency of coal-fired power plants, taking J-POWER as an example. Increases in power generation efficiency to date have been achieved mainly through technological advances in two areas: improvements in the steam conditions of steam turbines i.e., increases in steam temperature and steam pressure and increases in the unit capacity of power generation. Steam conditions have improved as technology has advanced from subcritical in the 1960s to supercritical in the 1980s, and then to ultra-supercritical (USC) with the entry into operation in 1997 of the Matsuura Thermal Power Plant s No. 2 Unit. Steam conditions have continued to improve since then, with the Isogo Thermal Power Plant s newest No. 2 Unit, which entered service in July 2009, operating at a reheat steam temperature of 620 o C, which is highest in the world.. Presently, around one third of Japan s coal-fired power generation capacity consists of USC plants. 4

5 Figure Operation and maintenance of coal-fired power plants Figure 5 shows the changes over time in power generation efficiency at two coal-fired power plants. Proper operation and maintenance is crucial if efficiency is to be maintained. Routine monitoring of plant performance and inspection of plants, and appropriate operation and maintenance in accordance with the findings, are prerequisites for maintaining efficiency. As plants operate for around 40 years, proper operation and maintenance over the long term is just as important as the construction of high-efficiency plants. Organizations including the Power Generation and Transmission Task Force of the Asia-Pacific Partnership on Clean Development and Climate (APP) are currently working on identifying best practice in individual countries and sharing information on technologies to assist efficient operation and maintenance. Figure 5 Thermal Efficiency (%, HHV) Takasago Power Station Unit 1 & Unit Designed Efficiency Efficiency Degradation 20 Coal-fired Plant in Country-X Year since Commissioning Source: Federation of Electric Power Companies, Japan (actual data for Takasago)

6 3-3. Environmental measures employed at coal-fired power plants Figure 6 shows a comparison of emissions of sulfur oxides (SOx) and nitrogen oxides (NOx) from thermal power plants in several developed countries. Measures of this kind are markedly more advanced in Japan than in developed countries in Europe and North America. The technologies typically used in Japan are flue gas desulfurization systems for dealing with SOx, and combustion improvement and de-nox In emerging economies such as China, solving conventional environmental problems such as these is an extremely urgent priority. SOx and NOx are not only harmful to human health, but also give rise to environmental problems such as acid rain. As acid rain aggravates forest damage, action of this kind to reduce atmospheric pollutants helps preserve the forests that act as carbon sinks. Figure 6 g/kwh SOx and NOx emissions in coal-fired power generation USA Canada UK (2005) (2005) (2005) France Germany Italy Japan (2005) (2005) (2005) (2007) Sulfer Oxide (SOx) Nitrogen Oxide (NOx) Isogo (2007) Source: Federation of Electric Power Companies, Japan (and actual data for Isogo) 3-4. Effect of replacement of aging coal-fired power plants Figure 7 shows a concrete example of environmental improvements that can be achieved by replacing an aging coal-fired power plant; in this case, J-POWER s Isogo Thermal Power Plant. The old Isogo Thermal Power Plant was a subcritical plant built in the late 1960s, but the new Isogo Thermal Power Plant uses the latest USC technology, dramatically increasing gross efficiency. Coupled with reductions in auxiliary power requirements achieved through technological advances, the result is a reduction in the CO 2 emission intensity on the net basis by as much as 17%. Other advanced environmental steps have also been taken, including installation of a dry flue gas desulfurization system, resulting in emissions of conventional atmospheric pollutants (SOx, NOx, and dust) being reduced to almost zero and putting the plant on a par with natural gas-fired power 6

7 plants. Figure 7 4. State of the world s coal-fired power plants and potential for CO 2 emission reduction 4-1. State of the world s coal-fired power plants Figure 8 shows the proportions of coal-fired power plants in major countries that operated under at least supercritical steam conditions as of 2005, according to IEA data. Worldwide, approximately 20% of coal-fired power plants are high-efficiency plants that are supercritical, and approximately 80% are subcritical. Figure 9, meanwhile, shows a breakdown of the ages of the world s coal-fired power plants by size. Many coal-fired power plants presently in operation are small old plants with a capacity of less than 300,000 kw that have been in operation for at least 25 years. The average efficiency of the world s coal-fired power plants is therefore relatively low at around 28% (net %, HHV). Factors such as the higher plant cost and more sophisticated operation and maintenance requirements of supercritical plants compared with subcritical ones, and the even greater cost gap where plants are small in scale due to the state of the power grid in a country, have probably discouraged the wider spread of supercritical plants. However, considerable reductions in CO 2 emissions can be achieved by replacing, modifying, and improving the operation of such small, aging coal-fired power plants, and estimates by the IEA put the potential for reductions in CO 2 emissions at between 1.35 and 1.7 billion tons. 7

8 Figure 8 Figure Power generation efficiency and CO 2 reduction potential of major countries Figure 10 shows a comparison of gross efficiency of coal-fired power plants in several major countries, and Figure 11 shows the CO 2 reductions that would be achieved by replacing all current coal-fired power plants in the U.S., China, and India with the best such plants in Japan based on the data shown in Figure 10. The reduction here is estimated to be approximately 1.3 billion tons, which is equivalent to approximately 5% of total world CO 2 emissions. These are of course no more than estimates, and there exist in practice many obstacles to actually implementing the necessary 8

9 replacement. The fact remains, however, that there exists considerable potential for reductions in CO 2 emissions. These estimates are based on present capacity. The IEA s WEO 2009 indicates, however, that construction of numerous new coal-fired power plants is planned, with China and India planning to build around 1,000 GW of new capacity, equal to almost double the present capacity. Considering that the lifespan of a coal-fired plant is in the region of 40 years, it is important that these planned plants be made as efficient as possible. Figure 10 Figure 11 Actual CO2 emissions from coal fired PS (2005) and Estimated emissions with best practice Mt-CO2 (JP Isogo #N1 efficiency) 2000 ( 377 ( 705) 377 (Mt-CO2) ) (Mt-CO2) (Mt-CO2) approx. 1300MtCO ( 22) ( 180) 0 Actual Emission BP Case Actual Emission BP Case Actual Emission BP Case Actual Emission BP Case Japan USA 9 China India Source: IEA World Energy Outlook 2007, Ecofys International Comparison of Fossil Power Efficiency and CO2 Intensity 2008 provided by FEPC

10 5. Roadmap for reduction of CO 2 emissions from coal-fired power plants There are two keys to solve the problem of global warming: technology and international collaboration. It is important to reduce world CO 2 emissions by promoting worldwide spread of currently available technologies, while at the same time pursuing the development and commercialization of more advanced technologies so as to set in motion a global cycle for the development, commercialization, transfer, and spread of such CCT. Figure 12 shows a suggested roadmap for the reduction of CO 2 emissions from coal-fired power plants. (1) In the short term (between now and c. 2020), introduction of highly efficient plants (USC, etc.) and use of wood biomass fuels (CO 2 neutral fuels) when new coal-fired capacity is built or aging plants are replaced. (2) In the medium term (c ), introduction of even more efficient plants (IGCC, A-USC, etc.), use of wood biomass fuels and partial adoption of CCS when new coal-fired capacity is built or aging plants are replaced. (3) In the long term (c ), introduction of the most efficient plants (IGFC, etc.), use of wood biomass fuels, etc., and full-scale adoption of CCS. *USC: Ultra-supercritical A-USC: Advanced ultra-supercritical IGCC: Integrated coal gasification combined cycle IGFC: Integrated coal gasification fuel cell combined cycle CCS: Carbon capture and storage In March 2008, the Japanese government announced the Cool Earth-Innovative Energy Technology Program, which identifies 21 innovative technologies to be prioritized, including high-efficiency coal-fired power generation technologies (IGCC, IGFC, and A-USC) and CCS technologies. This was followed in June 2009 by the Ministry of Economy, Trade and Industry s announcement of future Japanese coal policy. This proposes two initiatives: the Cool Gen Project to promote empirical research aimed at achieving zero emission coal-fired power generation by combining IGCC, IGFC (for the ultimate power generation efficiency), and CCS; and the Clean Coal for the Earth Project to promote the spread overseas of Japan s outstanding coal utilization technologies and to help combat global warming. 10

11 Figure Use of biomass fuels by coal-fired power plants Biomass fuels are solid fuels that may be regarded as being carbon free. As coal is also a solid fuel, biomass fuels can easily be used together with coal by coal-fired power plants. As Figure 13 shows, various types of biomass fuels are available, including carbonized municipal waste, dehydrated or carbonized sewage sludge, and wood biomass. In Japan, action is underway to introduce these various biomass fuels. Mixed use of biomass fuels is an immediately effective means of reducing CO 2 emissions. It contributes to recycling if waste is used, and effectively preserves forests and secures carbon sinks if thinned wood from forests is used. Wood biomass fuel can be burned at a concentration of around 3% at existing coal-fired power plants, and it is considered technically possible to raise this figure to 10% by installing separate fuel feed systems. In this case, however, securing stable and economical supplies of biomass resources would become an issue. 11

12 Figure Development of high-efficiency coal power technologies Figure 14 shows next generation, high-efficiency coal power technologies. Development of more efficient coal power technologies is taking two directions. The first is coal gasification technology. Integrated coal gasification combined cycle technology (IGCC) consists of gasifying coal to syngas which is used to generate electricity combined with gas turbines and steam turbines. If 1,500 o C-class gas turbines of the kind used for natural gas can be adopted, it should be possible to achieve an approximately 13% reduction in CO 2 emissions in relative terms compared with the currently most efficient coal-fired power generation technology. Integrated coal gasification fuel cell combined cycle (IGFC) technology lies further down the road than IGCC, and aims to make use of certain syngas, such as H 2 and CO, to power fuel cells in order to produce electricity even more efficiently by means of a triple cycle. If achieved, this would enable CO 2 emissions to be reduced by at least 25% in relative terms compared with at present. Figure 15 shows the coal gasification power technologies presently under development in Japan. In Japan, both air-blown and oxygen-blown methods of entrained-bed coal gasification technologies are being developed. Air-blown technology is being developed for the purpose of IGCC development, while oxygen-blown technology is being developed for multipurpose applications and for use in power generation as part of IGFC as well as IGCC systems. Development of air-blown IGCC is being pursued by Clean Coal Power R&D Co., Ltd. at a 250,000 kw pilot plant funded by power utilities. Construction of the plant has been completed, and 12

13 trials now underway at what represents the final stage of development prior to commercialization are steadily producing results. Regarding oxygen-blown technology, on the other hand, tests are being carried out by J-POWER at the EAGLE pilot plant, where CO 2 capture tests are also now being conducted. Building on the results of EAGLE pilot trials, the next stage will be a 170,000 kw-class output IGCC demonstration trial and CO 2 capture tests will be undertaken jointly by J-POWER and Chugoku Electric Power. In Japan, too, commercialization of coal gasification technology is now very close to commercial use. Secondly, there is advanced USC, whose target is to raise the steam conditions of pulverized coal-fired power generation to the 700 o C level. Development of materials for high-temperature, high-pressure is presently being pursued in Japan, and component tests using actual plants are planned. Figure 14 PC 1500 class GT IGCC IGFC USC 700 class A-USC Gas Turbine Fuel Cell Gas Turbine Boiler Steam Turbine Boiler Steam Turbine Gasifier Steam Turbine Gasifier Steam Turbine Gross:43%(HHV) Net : 41%(HHV) Gross:50% Net : 48% Gross:51-53% Net :46-48% Gross:60% above Net :55% above * CO2 reduction rate is based on latest USC plant. Thus the reduction rate becomes much higher when using existing plants as a base. Figure 15 Coal Gasification Air-blown (IGCC) Organization: 11 Power Co. + CRIEPI Coal Consumption: 1,700t/day(250MW) Test Period: FY CCP R&D Nakoso P/S Coal Gasification Oxygen-blown (IGFC) Organization: J-Power / NEDO Coal Consumption: 150t/day Test Period: FY J-POWER Wakamatsu R.I. EAGLE Pilot Plant Coal Gasification 燃焼前回収法微粉炭火力発電 Oxygen-blown (IGCC /CO2 ) Organization: J-Power / Chugoku J パワー 若松研究所 Chugoku Osaki P/S EAGLE 試験装置 Coal Consumption: 1,100t/day(170MW) Osaki Cool Gen Test Start: 2017/3 (planned) 13

14 5-3. Development of CO 2 capture and storage technologies Carbon Capture and Storage (CCS) is a method of capturing and storing CO 2 emitted when fossil fuels are used, and it is drawing growing interest worldwide as the prime element in a portfolio of techniques for achieving substantial reductions in CO 2 emissions. CO 2 is captured from CO 2 emission sources such as thermal power plants, transported by pipeline or ship, and stored in the ground or under the sea, and CCS requires that the capture, transportation, storage of CO 2 all function together as an integrated system of disposal for it to work. While CCS offers a potentially key means of reducing CO 2 emissions, it must be remembered that the technology required is still at the development stage and numerous challenges remain to be resolved. As CO 2 capture also requires considerable energy and penalize efficiency, the efficiency of power plants needs to be increased to the full. There are three main ways of capturing CO 2. Two are for capturing CO 2 produced by pulverized coal power plants, which are presently the commonest form of coal power plants. These are: post-combustion capture and oxy-fuel combustion. The third method for capturing CO 2 from coal gasification power generation is pre-combustion capture. In Japan, several CO 2 capture pilot tests are underway. Figure 16 shows the current state of development of CO 2 capture technologies by J-POWER. Regarding investigative research into CCS, Japan CCS Co., Ltd. was formed in May 2008 with the involvement of 37 companies in the private sector, including oil developers, power utilities, engineering companies, and steel producers, and plans for surveys of several storage sites and CCS demonstration trials are under development. Numerous challenges must be overcome technical, economical, environmental, and otherwise before CCS can be successfully commercialized. In the years ahead, knowledge and experience of CCS must be urgently accumulated through the development of technologies, surveying of storage sites, and real-world testing based on cooperation between the government and private sectors. As regards the development of technologies, it is necessary to pursue reductions in CO 2 capture energy and capture cost requirements, and to conduct more detailed surveys of potential sites to expand storage potential. Due to the possibility of multilateral partnerships owing to uneven global distribution of storage sites, it is important that flexible mechanisms such as CDM be made applicable. CCS entails considerable energy and cost inputs. For it to become a commercial reality, therefore, hardware is not the only thing that will be required; it is also essential that governments develop the necessary institutional support in terms of policy, finance, and legislation. 14

15 Figure 16 PCF Oxy-fuel PCF Post-combustion Coal Gasification 燃焼前回収法微粉炭火力発電 Pre-combustion Organization: Australia/JP,IHI Mitsui Scale: 30MW class CO2 captured: 30,000 t-co2/year Test Period: (planned) Organization: J-POWER/ MHI Gas Flow: 1,750Nm3/h CO2 captured: 10 t-co2/day Test Period: 2007/ / 3 Organization: J-POWER / NEDO Gas Flow: 1,000Nm3/h CO2 captured: about 20 t-co2/day Test Period: 2008/ / 3 Australia Callide P/S J-POWER Matsushima P/S Chemical Absorption T.E. J パワー 若松研究所 EAGLE 試験装置 J-POWER Wakamatsu R.I. EAGLE Pilot Plant 6. Cycles of CCT development, commercialization, transfer, and dissemination Figure 17 presents a scheme for the development, commercialization, transfer, and dissemination of CCT. There are still many low-efficiency subcritical power plants in operation around the world, and many new ones are also being built. As previously noted, application of high-efficiency technologies as epitomized by already-available USC technologies would enable major reductions in CO 2 emissions and preservation of coal resources. Developed and developing countries should work together to transplant and promote the spread of high-efficiency power generation technologies through partnerships between the government and private sectors. To achieve this, bilateral and multilateral frameworks for the introduction of high-efficiency power generation technologies need to be put in place, and various incentives and domestic policies introduced to remove technical obstacles and to eliminate the problem of increased costs. Creating an attractive business environment for the private enterprises that should play the principal role in promoting the spread of technologies is the key to promoting the adoption of high-efficiency power generation technologies. Developing the next generation of high-efficiency power generation technologies and CCS technologies to follow on from USC will also be important. In order to work toward the ultimate objective of achieving zero emissions, it is necessary to pursue the development, commercialization, and spread of innovative low-carbon technologies as coal-fired capacity is built and replaced. What we need to do so is ensure that the technologies developed jointly with developed or developing countries are steadily transplanted to and adopted in developing countries, and pursue reductions in world CO 2 emissions through a global cycle of development, commercialization, transfer, and dissemination. 15

16 Figure 17 Conclusion The situation surrounding energy and global warming is filled with uncertainties, and we have to recognize the fact that every energy resource has its advantages, disadvantages, and attendant risks. There is, then, no single energy magic bullet. As an energy resource, coal is essential to the world s energy security. For Japan in particular, with its poor energy self-sufficiency, coal has an essential role to play in helping to create a balanced and flexible energy supply portfolio. Given this environment, it is important to pursue the development and spread of clean coal technologies in order to reduce CO 2 emissions. The basic goal should be to pursue sustainable growth while maintaining a balance between the three Es, i.e., energy stability, economic efficiency and environmental harmony. Global warming is a complex problem that involves many challenges, such as balancing energy and environmental needs and tackling long-term multilateral issues on a global scale, and arguing that coal use should be limited solely on the grounds of CO 2 emissions is too simplistic to meet these challenges. The problem of global warming is a global one, and a global approach based on international cooperation is indispensable. By promoting the global spread of currently-available technologies while even cleaner CCTs are developed and commercialized to build up best practice that can be introduced around the world, it should be possible to achieve major reductions in world CO 2 emissions. The keys to tackle global warming are technology and international cooperation. CCT that improves efficiency and makes coal power cleaner needs to be deployed worldwide, and in this 16

17 Japan has a role to play in leading the world. REFERENCES 1. BP Statistics 2009, Statistical Review of World Energy IEA, World Energy Outlook IEA, Electricity Information Agency for Natural Resources and Energy of Japan, Overview of Development of Power Sources Federation of Electric Power Companies of Japan, Possible MRVable Indicators for Power Sector - Workshop on mitigation potentials, comparability of efforts and sectoral approaches 6. Bhattacharya, S., IEA Activities in Cleaner Fossil Fuels, Poznan, Poland (December 9, 2008). 7. ECOFYS, International Comparison of Fossil Power Generation Efficiency IEA, World Energy Outlook ECOFYS, International Comparison of Fossil Power Generation Efficiency and CO2 intensity