Introduction and Evolution of Gasification Melting Furnaces in Toyohashi City, Aichi Prefecture: 1999 to 2020s

Introduction and Evolution of Gasification Melting Furnaces in Toyohashi City, Aichi Prefecture: 1999 to 2020s

Background of Introduction and Initial Efforts (1999)
In 1999, a direct-coupled gasification and melting furnace by Mitsui Engineering & Shipbuilding was introduced in Toyohashi City, Aichi Prefecture, becoming a new model case for waste treatment and environmental protection in the region. This innovative technology separated waste into pyrolysis gas and residue, which was then completely combusted at a temperature of over 1,400°C to significantly reduce dioxin and other toxic substances. In addition, the glassy slag produced after pyrolysis could be reused as road materials, thus simultaneously turning waste into a resource and reducing environmental impact.

With an initial capacity of approximately 100,000 tons of waste per year, the facility attracted the attention of Toyohashi City and other municipalities in and outside of Aichi Prefecture. The facility led the evolution of waste treatment technology in Japan and had a significant impact on environmental policy from the 2000s onward.

Evolution of Technology and Efforts to Address Challenges (2010s)
In the 2010s, Toyohashi's gasification and melting furnaces improved their capacity and efficiency through facility upgrades and operational improvements. The annual waste treatment volume increased to 150,000 tons, which now includes not only general waste but also industrial and plastic waste.

Major developments during this period included

Increased energy recovery efficiency
A gas turbine power generation system was partially installed, increasing the efficiency of generating thermal energy from waste by 25%. The amount of electricity generated reached 35,000 MWh/year, enough to power approximately 1,000 households.

Enhanced recycling
Recycling technology for slag and metal resources obtained in the waste treatment process has been improved. 1,000 tons of slag are used as road materials annually, and the recovery of iron, copper, and aluminum has increased by about 20% each.

Contribution to the Local Economy
Through the operation of the facility, Toyohashi City has created new employment opportunities in cooperation with small and medium-sized businesses and recyclers in Aichi Prefecture. The facility also accepted waste from neighboring Shizuoka and Mie prefectures, expanding its role as a wide-area waste treatment center.

At the same time, however, the facility was aging and operating costs were rising. To address these issues, automation of the operation management system and introduction of more efficient technologies were promoted.

Current Status and Further Evolution (2020s)
In the 2020s, the facility will be further upgraded to achieve an annual waste treatment capacity of 200,000 tons and an annual power generation capacity of 5,000 MWh. Exhaust gas purification capacity is maintained at levels well below environmental standards, and slag recycling is expanded to 5,000 tons per year.

Notably, the plant aims not only to improve the efficiency of waste treatment, but also to create a zero-emission society within the region, and with plans to introduce technology to convert emissions into hydrogen by 2025, it is attracting attention as a center for utilizing hydrogen energy within Aichi Prefecture.

In addition to Mitsui Engineering & Shipbuilding, JFE Engineering, Ebara Corporation, and other companies are involved in the operation of the facility, which is promoting both technological innovation and local economic revitalization. In addition, a wide-area waste acceptance system has been established, and industrial waste from Gifu and Shizuoka prefectures is efficiently processed.

Historical Significance
For more than 20 years since its introduction in 1999, the gasification melting furnace in Toyohashi, Aichi Prefecture, has contributed to the evolution of waste treatment technology and the building of a sustainable society. The technological evolution and its impact on local communities, especially since the 2010s, are symbolic of Japan's environmental policy and the development of a resource-recycling society. The facility will continue to play an important role as a model case for waste treatment technology in Japan and abroad.