MHIEC Receives Order for Full Refurbishment of Waste Incineration Plant in Itoman City, Okinawa Prefecture
-- Renovation to Extend Service Life, Enhance Energy Efficiency, and Reduce CO₂ Emissions at Itotoyo Environmental Improvement Center --

Tokyo, March 31, 2025 - Mitsubishi Heavy Industries Environmental & Chemical Engineering Co., Ltd (MHIEC), a part of Mitsubishi Heavy Industries (MHI) Group, has received an order from the Nanbu Wide-area Administration in Okinawa Prefecture for a full refurbishment of its Itotoyo Environmental Improvement Center (Tsukazato, Itoman City). The order calls for renovation of the facility's stoker type incinerator, capable of processing 200 tonnes per day (tpd) (Note1), to extend the plant's service life, enhance its energy efficiency, and reduce CO₂ emissions. The contract is valued at 1.506 billion yen (tax excluded), with completion scheduled for March 2026.

The Itotoyo Environmental Improvement Center was originally designed and constructed by MHI. On completion in March 1998, the facility incorporated two stoker type incinerators, each providing a processing capacity of 100 tpd, plus related equipment.

The purpose of this project is to upgrade the main equipment of the aging water supply equipment, electrical instruments, and exhaust gas treatment equipment and enhance energy efficiency through the adoption of high-efficiency motors and transformers. A new steam turbine with a generating capacity of 295kW will be installed and effective use will be made of excess steam from the boiler to reduce electricity purchasing. The project aims to reduce annual CO₂ emissions by 3% or more from the previous year. The durability of the exhaust gas treatment facilities will be improved and chemical usage will be reduced through the adoption of a proprietary Hybrid Bag Filter® (HBF) made of Polytetrafluoroethylene (PTFE) from MHIEC(Note2), which utilizes filter cloth used in dust collection filters, achieving world-leading removal of dioxins. This will also contribute to reduction of life-cycle costs (LCC).

In recent years, there has been an increase in refurbishment work to extend the service life of waste-to-energy facilities and address climate change. To facilitate further work of this nature, the Ministry of the Environment has established subsidies for waste-to-energy facilities(Note3) for purposes such as assisting waste-to-energy facilities in the adoption of advanced equipment.

MHIEC succeeded MHI's environmental protection business in 2008, taking over its accumulated technological development capabilities in environmental protection systems and abundant expertise in the construction, operation, and maintenance of waste management facilities both in Japan and overseas. Based on this robust track record, the company is well positioned to propose comprehensive solutions encompassing all aspects from plant construction to operation and maintenance. Based on this project and its past record, MHIEC will continue to seek order expansion through proactive offering of proposals for enhancing the efficiency of existing facilities, maintaining and improving the stability of operations, and lowering LCC.

• 1A stoker furnace is the main type of waste-to-energy plant. Air is supplied from below a fire grate made of heat-resistant castings to propel the materials to be burned (waste, etc.).
• 2Bag filter fibers are coated with a catalytic agent to maintain their standard function of removing toxic materials while improving their functionality through the additional ability to break down dioxin gases and NOx (nitrogen oxides).
• 3Municipal governments seeking to extend the service life of their waste-to-energy facilities and implement climate change countermeasures are eligible for subsidies on projects that will reduce CO₂ emissions (promoting the introduction of leading-edge facilities), or grants for establishing a sound material-cycle society, equivalent to one-half or one-third of project costs.