Environmentally friendly energy system models using material circulation and energy cascade - The optimization work

The objectives of this paper are to develop advanced energy management systems for an energy efficient and environmentally friendly society and to provide an assessment model for zero emission (of materials) and energy cascade systems. This paper introduces two types of advanced energy system models: energy cascade with zero emission by material circulation and a super environmentally benign industrial district from the viewpoint of complete energy utilization and environment conservation. An assessment model is developed to quantify the energy saving effect from the advanced energy cascade systems which consist of four major industry groups and 12 subgroups in Japan. The results show that an energy saving effect of 25% could be realized from the zero emission and energy cascade systems. It is, moreover, found that the minimum fuel and energy consumption rate could be obtained from an optimum area composition of major groups. This paper develops an energy cascade balance table which indicates the material and heat flow directions from a higher potential level to a lower potential level. The table proposes current energy consumption with respect to temperature level. The proposed energy models demonstrate how to maximize the heat utilization among various industries.