The Japanese government launched the "Cool Earth-Innovative Energy Technology Program" in March 2008 to contribute to the reduction of substantial global greenhouse gas emissions. 21 technologies, which can contribute to substantial reductions in CO_2 emissions through efficiency improvement and low carbonization, were selected. The Advanced Ultra Super Critical pressure power generation (A-USC), which aims to commercialize a 700 deg-C class pulverized coal (PC) power system with 46% power generation efficiency by around 2015, is included in the technologies. The capacity of PC power plants in Japan rose to 35GW in 2004. The latest plants have a 600 deg-C class steam temperature and a net thermal efficiency of approximately 42% (HHV). On the other hand, aged plants, which were built in the 70s and early '80s, will reach the point where they will need to be rebuilt or refurbished in the near future. The steam temperatures of the older plants are either 538 deg-C or 566 deg-C. We did a case study, retrofitting these plants with the advanced USC technology that uses a 700 deg-C class steam temperature to increase the thermal efficiency and to reduce CO_2 emissions. The study showed that the A-USC Technology is suitable for retrofitting older plants and can reduce CO_2 emissions by about 15%. This study was introduced at the last conference in 2007(1).Based on the study, we started a large-scale development of the A-USC technology in August 2008. 700 deg-C class boiler, turbine and valve technologies, which include high temperature material technology, are being developed. Some candidate materials for boilers are being tested. Turbine rotor and casing materials are being developed and tested, as well.Two years into the project, we have obtained some useful test results regarding the candidate materials.
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