Innovation for realizing a sustainable low carbon and high exergy efficiency society

  A low carbon society and sustainable energy system are simultaneously realized by (1) expanding the use of wastes and renewable resources and (2) improving exergy efficiency of processes. For the promotion of those two... [ view full abstract ]

  A low carbon society and sustainable energy system are simultaneously realized by (1) expanding the use of wastes and renewable resources and (2) improving exergy efficiency of processes. For the promotion of those two fundamental measures, following innovations are required.

  To expand the use of wastes and renewable resources, the supply demand balance of wastes and biomass (one of promising renewable resources) is vital to build a steady utilization system of them. Recent technological development of IoT (Internet of Things) makes it much easier to bring a balance between a supply side and a demand side in a broader area. Wastes and biomass are transported to a most appropriate facility which can utilize them efficiently.

  To improve exergy efficiency, conventional energy saving measures such as reducing heat ross by strengthening thermal insulation performance contribute. However, to accelerate the transition to a decarbonized society, high exergy use of wastes and biomass is one of the key solutions. For such a high exergy use of those low carbon resources, upgrade use of them in industrial processes provides a clear guideline. Fossil fuels are not used with the full efficiency of exergy in industrial processes. If wastes and biomass are used together with fossil fuel by a direct or an indirect mixture method in a factory or a thermal power plant, they can be used with around two times higher exergy efficiency than the case wastes and biomass alone are used in a conventional process such as waste power generation. Then the ratio of fossil fuels can be decreased in steps to reduce carbon dioxide emission.

  In the future, from the viewpoint to use surplus electricity generated by photovoltaics, making a conventional industrial process relying on fossil fuels into hybrid one which use both electricity and fossil fuels would be effective in order to use much more renewable energy stably in industries. The fossil fuel in the hybrid processes can be replaced by hydrogen produced from renewable energy sources in due course of time. Based on the result of qualitative and quantitative evaluation by a thermodynamic model, the effectiveness of above innovations is discussed in this paper.