Japan is the world's largest importer of coal. We have developed the advanced clean coal technology such as high-efficiency coal fired power plant (PFBC, USC, A-USC) , gasification (IGCC) and liquefaction technology by promoting technological cooperation among public and private sectors. Japanese Government has been providing financial and technical support to R&D activities on clean coal technology and technology transfer to overseas countries mainly in south and east Asia. Furthermore, Japan is also promoting the demonstration project of integration of IGCC and CCS with international cooperation through bilateral framework and multilateral framework such as IEA, CSLF, APP and APEC. Japan will contribute to solving the climate change issues by advancing clean coal technology and promoting its technology transfer.
All advanced countries face the global environment issue to reduce drastically CO2 emission in the coming 50 years of this century. Iron making and power generation industries in Japan consume a huge amount of coal because of its reasonable cost and stable supply. Hence they are strongly requested to reduce CO2 emission. Iron making industry has developed a series of technologies to produce high quality steel products for saving the energy consumption over the world at the minimum energy consumption, applying raw materials and energy of low quality. Nevertheless they are asked to develop the technology to reduce further CO2 emission. In the present review, the authors summarize a series of the iron making technology developed recently and currently under development to meet future regulation of CO2 emission. The blast furnace, coke making oven and sintering of iron ore are major steps of iron making. Coal and coal derived products are heavily applied and higher efficiency of their use has been attempted. Industrial complex reconstruction, as well as technological development are continuously intended in the coming years.
Global warming should be an urgent issue to be undertaken by all the major economies in the world. Simultaneously, developing countries, especially the least developing countries, need to achieve economic growth to provide better living standard to their people, most of who are facing difficult life because of low incomes and growth of economies. In order to achieve necessary growth, those countries surely need supply of primary energy, mostly oil and coal, to be increased, since many of those countries do not have any facility or technology to utilize renewable energy yet, such as wind or solar and need to consume conventional energy sources with current equipment. How we can fight with climate change, achieving economic growth of developing countries, which still need large amount of fossil fuels supply. We seem to be facing difficult task. One of the answers is transfer of technology, which we have in Japan, to developing countries for improving efficiency of energy related plants, and rehabilitation or renovation of old facility to save energy consumption and reduce greenhouse gases.
CO2 sequestration into a depleted oil reservoir has been expected to be a method of reducing the CO2 emission. We focus on the in-situ microbial conversion of CO2 into CH4 by hydrogenotrophic methanogens that inhabit oil reservoirs universally. It is important for this conversion process to accelerate the supply of H2 for the CH4 production by methanogens in reservoirs. This study aims to search for oil-degrading and H2-producing thermophilic bacteria (ODHPTB) that can produce H2 from oil in reservoir brine. Reservoir brine was extracted from 10 producing wells in Yabase Oilfield in Japan. Indigenous bacteria in brine were incubated with sterilized oil under anaerobic conditions (10% CO2 and 90% N2) at 50°C and/or 75°C. Both the production of H2, CH4, and the consumption of CO2 were observed in almost all culture systems after 2 months incubation. The maximum production of H2 was 1267 Nml/l-med. for 4 months incubation. Petrotoga sp. and Thermotoga sp. which were reported as ODHPTB were detected as dominant bacteria from each enrichment culture solution by gene analysis. These culture solutions and raw brine were inoculated into nutrient agar medium and incubated under anaerobic conditions at 50°C and/or 75°C. Microbial single colonies which were formed in the nutrient agar medium after 2 weeks incubation were picked and inoculated into sterilized brine including sterilized oil as sole hydrogen source. More than 38 strains were isolated and incubated in the brine medium, and then producing hydrogen from oil were observed from 38 strains after 1 month incubation. The maximum production of H2 was 26 Nml/l-med. for 3 months incubation. These results show the in-situ microbial conversion of CO2 and residual oil into CH4 using ODHPTB and hydrogenotrophic methanogens is promising. Moreover, the valuable characteristics of ODHPTB isolated in this study, made it suitable to be injected into reservoirs to stimulate the conversion of CO2 into CH4.
CO2 capture and storage (CCS) is one of expected methods to reduce CO2 emissions into the atmosphere. The Japan consortium to proceed the CO2 sequestration into coal seams carried out the project "Japan CO2 Geosequestration in Coal Seams Project (JCOP) " on CO2 injection and CH4 production during 2002 to 2007 at Yubari City, Hokkaido, which is hereinafter called as Yubari ECBMR pilot test. A targeted coal seam at the project was located about 890m below the surface. The project had a problem on CO2 injection with low injection rate of about 3ton/day. In the pilot-test data, it was observed as a common pattern that CO2 injection rate was decreasing during 3 to 10 days after starting CO2 injection, because of decreasing permeability around the injector. The maximum decreasing ratio of the permeability was evaluated as 1/50 of the initial one. The reason was assumed by swelling of the coal seam around the injector by injection liquid CO2. In this study, an analytical model has been presented in consideration of permeability reduction by swelling. Present predictions on CO2 injection rate with the model have been matched with monitoring data measured at the Yubari ECBMR pilot test. The ratio of permeability reduction of coal seams by the swelling (swelling factor) has been evaluated as 1/50 to 1/16. In this research, numerical simulations, which use double porosity model and Palmer & Mansoori model to express permeability reduction by shrinkage of micro-pores caused by CO2 adsorption, called as coal matrix swelling, has been carried out with the ECLIPS (CBM option) . A history matching study was conducted to estimate CH4 desorption time and production bottom-hole pressure (BHP). Other reservoir parameters such as pore compressibility and gas-water relative permeability curve, were set based on the report of Yubari pilot test and previous researches by Yamaguchi et al. (2007) and Pekot & Reeves (2002) . The numerical simulations for sensitivity studies on CO2 injectivity and CH4 productivity have been carried out by giving CO2 and CH4 adsorption capacities and viscocities of CO2 and water as a function of the coal seam temperature (30 to 60 °C) . Finally, the numerical simulation results with five spot model have been presented to evaluate CO2 injectivity and CH4 productivity by changing the well spacing. The results show that CO2 injection is roughly proportional to number of injectors, however the time at the maximum CH4 production rate is delayed with area including four production wells. From view of economical evaluation, drilling cost of wells and accumulated present value of revenue of CH4 production will be important to decide the optimum well spacing.
Mine ventilation measurements using with SF6 as tracer gas were carried out at Kushiro Coal Mine operated by Taiheiyo-tanko Co., Ltd. in 1997, in order to investigate the flows in the inclined airway and its network flows from the inlet portals to the main fan. The photo-acoustic gas monitor of SF6 with high sensitivity of 10 ppb resolution of gas concentration was used to measure gas concentration-time curves. Two injection methods were applied to measure airflow in the inclined shaft by stepwise gas injection, and the ventilation network flows by pulsed injection of the tracer gas from the inlet portals. The effective gas diffusion coefficient in the single mine airway has been investigated by the measurement and numerical simulation results, and it was evaluated as 20 m2/s that is almost same order to that of Taylor's equation. On the other hand, the effective diffusion coefficient in the large scale of mine ventilation network has been evaluated as 200 m2/s that is one order larger value to Taylor's one. As the result of the measurements, the effective diffusion coefficient in mine ventilation airways has been evaluated as one order larger than usual turbulent diffusion coefficient (≈ 2∼25 m2/s) , and the average traveling velocity of tracer gas was about 70% to the average airflow velocity to the flow passes. Authors have presented a possible mechanism of the large effective diffusion coefficient and delay of the gas travelling in mine airways, that are generated by weak re-circulated flows formed in dead spaces and roads connecting main airways without airflows. Furthermore, the revised equation and numerical method for gas concentration-time curves in mine network ventilation flows has been presented which was extended from the Taylor's equation to evaluate effective diffusion coefficient of a single flow channel, and it has been shown that the presented model can be used for matching with the measured results including gas diffusion characteristics of mine ventilation airflows.
The world produced over 6.7 billion tons of coal in 2008. Coal is one of the world's most important resources of energy, generating almost 40% of electricity worldwide. The world relies on coal for about 30% of the primary energy consumption in the Asia Pacific region. The largest coal producing countries are not confined to one region. Coal will continue to play a key role in the world's energy mix, with demand in certain regions, such as Asian countries, set to glow rapidly. The world consumption of coal can have a significant impact on the environment. Minimizing the negative impacts of human activities-including coal utilization- is a key global priority. Essentials to continue the clean use of coal are economically efficient and stable supply. It is also important to evaluate non-conventional type resources such as low rank coal and Coal Bed Methane/Coal Mine Methane, to raise an increase of the amount of the resources and the resources recovery rate.
Fossil fuels including coal play a key role as crucial energies in contributing to economic development in Asia. On the other hand, its limited quantity and the environmental problems causing from its usage have become a serious global issue and a countermeasure to solve such problems is very much demanded. Along with the pursuit of sustainable development, highly effective utilization technology of fossil resource with considering environmental problems should be therefore, accompanied. Kyushu-university's sophisticated research through long years of accumulated experience on the fossil resources and environmental sectors together with the advanced large-scale commercial and empirical equipments will enable us to foster cooperative research and provide internship program for the future researchers. Then, this program is executed as a consignment business from the Ministry of Economy, Trade and Industry from 2007 fiscal year to 2009 fiscal year. The lecture that uses the textbooks developed by this program is scheduled to be started a course in fiscal year 2010.
The global warming and the depletion of natural resource deposits have become a serious issue worldwide. In order to alleviate these issues, a process development for coal-based direct reduction technology has been carried out. Offering a solution to recover steel mill waste including EAF dust, the FASTMET® Process produces valuable DRI and crude zinc oxide from the steel mill waste which contains valuable metals such as zinc. Moreover the ITmk3® Process can produce iron nugget which is equivalent as pig iron by using low grade iron ore fine as well as steaming coal. This suggests that coal-based direct reduction technology could be a solution to alleviate both issues mentioned above.