Nakoso IGCC plant complete in Japan, to support Fukushima recovery

April 23, 2021
Rory Pasquariello

A consortium led by Mitsubishi Power, a subsidiary of Mitsubishi Heavy Industries (MHI) group, has completed the construction of an integrated coal gasification combined cycle (IGCC) plant in Iwaki, Fukushima, that was followed by the formal handover to the customer, Nakoso IGCC Power GK.

Operation of the new facility, which is a commercial power plant incorporating coal gasification technologies, got underway on April 16. Mitsubishi Power manufactured the core air-blown IGCC system, including the coal gasification furnace. The project called for creation of the world's largest IGCC configuration, roughly twice the scale of the Nakoso Unit 10 (former IGCC demonstration plant) completed earlier. This is the first domestically developed air-blown IGCC system of such large scale in commercial use. Compared to the Unit 10, power generation efficiency has been substantially enhanced reaching 48%, which was enabled by the gas turbine's having a higher combustion temperature.

In this case, the IGCC plant adopts a high-efficiency “combined cycle” methodology. Coal is gasified in a gasification furnace at high temperature under high pressure; sulfur, ash and the like are separated out and removed; and the refined gas is used as fuel to drive a gas turbine. In this configuration, the gas turbine is combined with a steam turbine that operates using the steam generated by a waste heat recovery boiler fueled by waste gas. Compared to conventional coal-fired power plants, IGCC plants provide greater power generation efficiency and help to reduce carbon emissions. For these reasons, they do respond to the needs of power providers in their efforts to make effective use of resources while simultaneously protecting the environment.