Establishment of Innovative Carbon Nanofiber Synthesis Technology Utilizing Carbon Dioxide

The 18th century industrial revolution dramatically changed people’s lives and allowed for rapid growth of the global economy. However, since that time, the mass consumption of fossil fuels has resulted in the release of large amounts of carbon dioxide (CO₂) into the atmosphere, creating a greenhouse effect and global warming. In turn, global warming poses a serious threat to the workings of society. Thus, the immobilization of emitted CO₂ and the development of effective CO₂ utilization technologies are currently being investigated toward the development of a sustainable society. This study proposes the manufacture of carbon nanofiber (CNF) materials using CO₂ gas as a carbon source. It is expected that this technology will be valuable as a means of recapturing CO₂. We report herein the effects of CO₂ on CNF growth using CO₂ and hydrocarbon gases on simple catalytic chemical vapor deposition (CCVD) catalysts, including Fe, Ni, and Co. Four factors were examined: the effectiveness of the catalyst, the reaction temperature, the CO₂ concentration, and the specific hydrocarbons supplied in the feed gas. Use of these techniques will enable one to expect (1) future utilization of exhaust gas emitted from thermal power stations and factories as a carbon source and (2) the future possibility of directly converting CO₂ to CNF by utilizing the heat given off by emission from factories and other thermal power-generating facilities as a heat source in CNF synthesis, as well as the future possibility of proposing an effective CO₂ utilization system that will be revolutionary in its impact.