Mitsubishi Heavy Industries Environmental & Chemical Engineering Co., Ltd. (MHIEC) has completed a significant upgrade of the Hokubu Waste-to-Energy Plant in Kagoshima City, enhancing its capacity to process municipal solid waste while reducing carbon emissions.
The six-year project, spanning from fiscal 2020 to fiscal 2025, involved the renovation of the plant's stoker-type incinerators, which have a processing capacity of 530 tonnes per day. Originally constructed by Mitsubishi Heavy Industries and completed in March 2007, the facility now features two units of stoker-type incinerators, each capable of processing 265 tonnes per day, and related equipment that supports power generation.
Key improvements include the introduction of a low-temperature catalyst to the Selective Catalytic NOx Reduction (SCR) system, a proprietary MHIEC technology. This enhancement allows for increased heat recovery rates by removing nitrous oxides at lower temperatures without the need to heat exhaust gases to high temperatures.
Additionally, the plant adopted a low excess air ratio incineration technology to improve combustion efficiency and boiler performance. These upgrades have increased the output of the plant's steam turbines from 8,700 kW to 10,005 kW, leading to a projected reduction in CO2 emissions by approximately 33.1% annually.
MHIEC, which took over Mitsubishi Heavy Industries' waste treatment plant business in 2008, brings extensive expertise in environmental systems and waste management facility operation. The company aims to continue its role in extending the life of existing waste treatment facilities, addressing global warming, and reducing lifecycle costs to contribute to energy decarbonization through waste energy collection.