Currently, many studies on CCS and CCU are being conducted to solve global warming, but there is no effective method on CCU due to problems of CO2 conversion ratio and energy efficiency. Carbon recycling can be realized by converting CO2 into various hydrocarbon, and many hydrocarbons can be produced from CO and H2. Therefore, it is considered optimal to generate CO from CO2. However, since it is difficult to convert CO2 into CO and it is required a high temperature field over 2000 ℃ to thermally convert CO2 into CO, it is not very realistic. In addition, the study using plasma achieved CO2 conversion ratios of 23% with plasma only and 45% plasma + catalysis. On the other hand, the applicants have so far achieved CO2 conversion ratio of 43% with plasma only. In this study, we try to achieve CO2 conversion ratio of 80 to 90% or more by further devising.
Research concept: Microwave assisted conversion of CO2 to CO
CO2 is a very stable substance, and it is required a high temperature field over 2000℃ to thermally convert CO2 into CO. Thus, it is not very realistic. In recent years, studies have been conducted using electrocatalysis or photocatalysis that can be reacted at low temperature. However, there are still problems with CO2 conversion ratio and energy efficiency. This study has characteristics that it aims at high CO2 conversion ratio and high energy efficiency by using microwave plasma and so on.
Currently, a lot of studies on CCU are being carried out, but it is not expected many of them to be put into practical use in the future as an extension of the current technology. In the carbon recycling technology roadmap, announced by the Ministry of Economy, Trade and Industry, a goal has been set that various hydrocarbons such as alcohols, fuels and chemicals with high added values are produced directly form CO2 or are produced by mixing H2 and CO. Although these targets have been set, most of the hydrocarbons corresponding to these targets can be produced from CO and H2 with current technology. In other words, if CO2 can be converted into CO with high efficiency, it will be possible to produce high added value hydrocarbons by reacting the produced CO with H2. In this research group, a module consists of Yamamoto in plasma based reaction engineering, Kishida and Oshima in catalyst based reaction engineering, and Kudo in device design based reaction engineering, and we perform the study to achieve breakthroughs in conventional technology.