(350b) Self-Heat Recuperation and Its Applications in Chemical Industries

The combustion of fossil fuels for heating produces a large amount of carbon dioxide (CO2), which is the main contributor to the global greenhouse gas effect. Hence, the reduction of carbon dioxide (CO2) emission and the reduction of energy consumption for heating has nowadays become a very important issue in the efforts to suppress global warming. Heat recovery technology such as pinch technology, which exchanges heat between the hot and cold streams in a process, has been applied to thermal processes to reduce energy consumption. Although the net energy input seems to be reduced by using exhausted heat as the additional heat, the heat is also provided by the combustion of fossil fuels, leading to exergy destruction during energy conversion from chemical energy to heat.

Recently, Kuchonthara and Tsutsumi have proposed an energy and exergy recuperative integrated gasification power generation system and a design method for the system. Authors following on this concept and developed self-heat recuperation technology (SHRT) based on exergy recuperation. The most important characteristic of this technology is that the entire process stream heat can be recirculated into a process without any heat addition, leading to marked reduction of exergy and energy savings for the process.

In this research, the process design methodology based on self-heat recuperation is illustrated with the theoretical minimum energy required. Then, the energy required for processes based on self-heat recuperation and that for conventional processes with heat recovery in chemical industries are compared. From these results, the direction of energy saving process designs with fundamental developments is shown.