Agreement has been reached for the construction of an integrated coal gasification combined cycle (IGCC) plant in Fukushima Prefecture, Japan with a number of ASU producers thought to be interested in the project’s development.

Tokyo Electric Power, Mitsubishi Heavy Industry, Mitsubishi Electric and Joban Joint Power are the parties understood to be involved in the project.

The agreement will see the parties proceed with collaboration toward a world-class state-of-the-art IGCC plant, which Tokyo Electric Power had previously looked into for use in connection with the earthquake recovery in Fukushima.

More specifically, it states that two IGCC plants of approximately 540,000 kilowatts capacity each will be constructed and operated in the; one at the Tokyo Electric Power thermal power station in Hirono, and the other at the Joban Joint Power thermal power station in Nakoso.

With the plants set to start operation in the ‘early 2020s’ according to The Gas Review (TGR), the companies have already begun preparation as the ‘Fukushima Revitalisation Power Consortium’.

TGR explains that ASU (air separation unit) producers are interested in the project, as IGCC should bring about a demand for large ASUs.

IGCC is a method whereby coal is gasified and electric power is produced in a combined cycle involving a gas turbine and a steam turbine. More efficient than a cola-fired power station of the same scale, IGCC plants also contribute to a reduction in carbon dioxide (CO2) emissions.

Oxygen is used for partial oxidation in the gasification of coal, while nitrogen is used for the transportation of the crude coal and process purging.


Coal mining industry

Oxygen demand

A commercial-scale coal-fired oxy-combustion power plant requires thousands of tons of oxygen each day.

Currently, cryogenic distillation is the only commercially viable technology that will produce such large quantities of oxygen. Other air separation technologies like pressure swing adsorption, vacuum swing adsorption, and polymeric membranes cannot economically produce such quantities.

Ceramic membranes (oxygen ion transport membranes) are not yet commercially available for large-scale oxygen production, therefore making it difficult to compare them to cryogenic distillation, in terms of both investment and performance.

Cryogenic ASU performances have improved tremendously over the last 40 years. It is estimated that power consumption has been cut almost in half, while distillation column productivity (flow per square meter) has multiplied three-fold. The technology should continue to advance over the next decade, specifically through targeted improvements in oxy combustion and IGCC plants.

As an example in Japan, Mitsubishi Heavy Industries – one of the participants in the new IGCC project – has a strong track record in IGCC demonstration plants (on the grounds of Joban Joint Power) with an air-blown furnace using air and not oxygen for partial oxidation. At that plant, an ASU produced by Kobe Steel was installed.

Similarly, Chugoku Electric Power is moving along with the construction of an oxygen-blown IGCC demonstration plant at its Osaki power station in Hiroshima Prefecture, set to start operation in 2017. Air Liquide Japan has obtained the order for the accompanying ASU, with an oxygen generation capacity of 30,000 Nm3.

At a time when there is little new demand for such large ASUs in Japan, says TGR, ASU producers are naturally paying close attention to the development of this new IGCC project and its potential requirement for industrial gases.