The photo is sourced from nikkei.com
The power generation process takes place in several stages. First, coal is gasified with oxygen to produce synthesis gas, the main components of which are carbon monoxide (CO) and hydrogen (H2). Synthesis gas is then purified to remove sulfur and impunities. Most of this feedstock is fed into a combined cycle unit where thermal energy produced as a result of combustion in a gas turbine goes into the adjacent steam turbine, which generates additional power as a result. Some of this synthesis gas goes to the CO2 capture unit where carbon monoxide upon coming in contact with steam is converted into carbon dioxide, which is retained in the absorber. Upon the extraction of CO2, synthesis gas becomes a hydrogen-rich fuel. The fuel is fed into a solid oxide fuel cell, which is also used to generate electricity.
The results of this experiment will be used in the modernisation of a coal-fired power plant in Nagasaki Prefecture, which is supposed to be completed by 2026. The project will be implemented by J-Power, a Japanese company, which co-owns the Osaki CoolGen Corporation with another Japanese power company, Chugoku Electric Power.
According to Ember research centre, the share of coal in Japan’s energy mix stood at 33% in 2021. The other 67% were represented by gas (35%), fuel oil and diesel fuel (3%), as well as nuclear power plants (6%) and renewables (17%). At the same time, the commissioning balance of coal-fired power plants in Japan remains positive so far: Global Energy Monitor says that, in the period from 2019 through the first half of 2022, coal-fired TPPs with an overall capacity of 5.7 gigawatts (GW) were put in operation while 0.9 GW of capacity was decommissioned.