Utilization of wasted heat by thermoelectric materials

Mitsubishi Steel Mfg. Co., Ltd.

Thermoelectric conversion module

Outline

Appx. 70 percent of energy used in Japan are low temperature heat energy which is less than 300 Celsius, and its huge part are wasted by emitting from automotive, production facility and power plant, etc. If this kind of wasted heat will be able to utilized, that would lead huge technological progress.

Thermoelectric materials are transforming heat energy to electric energy and it is increasing attention as utilizing wasted energy.

Our company in steel industries have huge wasted energy emitted from production facilities, so we would like to contribute into realizing low carbon society through utilizing this kind of so called “ Mottainai (too good to waste) heat.

Description

Heat transformation is a technology to draw electric energy by utilizing thermo-electromotive force, which is generated by setting things with different temperature, and this is old famous principal as Seebeck effect. Energy transformation materials utilizing this Seebeck effect are called as thermoelectric materials, and recently several kinds of thermoelectric are researched and developed in the point of energy conservation and global warming countermeasures.

One of the representative thermoelectric materials is Tellurium compounds (Bi2Te3, PbTe) and Antimony compounds (ZnSb), but there are concerns that those are contacting heavy metals and/or toxic elements. In addition, cost is expensive due to rare metals, and heat transforming efficiency is not enough at current stage, so it has not become popular.

In case of use of actual energy transformation, thermoelectric conversion module is used, which composes thermoelectric devise, insulating plate and electrode. It is advantage of thermoelectric module that can be smaller and lighter, in addition, easy maintenance and generate no noise and no vibration.

Our company has paid attention to possibility of effective utilization of wasted energy, ex. emitted heat from production facilities, and has progressed development and research. It is our original powder based thermoelectric materials that are not using toxic elements and high cost rare metals in addition to considering manufacturability. We are going to move forward basic research stage into practical research stage.

We are going to spread our original thermoelectric material and utilize wasted plant emitted heat, then We hope it will contribute into realizing low carbon society.