Coal Gasification Technology
Coal Gasification Technology Q&A
What is coal gasification?
By adding a little bit of oxygen and heat and steaming the coal, fuel gas mainly comprised of carbon monoxide (CO) and hydrogen (H2) is created. The fuel gas is used to generate power. "Coal gasification" refers to the process of changing coal, a solid, into a fuel gas.
Why does coal gasification technology increase the generating efficiency?
In conventional coal-fired power generation, pulverized coal was burned in a boiler to create steam, and that steam was used to turn a steam turbine to generate power.
With the "Integrated Coal Gasification Combined Cycle (IGCC)," the coal is not burned in a boiler, but the gasified coal gas is used as a fuel for combined cycle power generation using both a gas turbine and a steam turbine, thus increasing the generating efficiency. As technology to further improve the generating efficiency, we plan to engage in establishing generating technology called "Integrated Coal Gasification Fuel Cell Combined Cycle (IGFC)," which performs a triple combined cycle using a fuel cell, gas turbine, and steam turbine.
How much CO2 can be reduced using coal gasification technology?
The generating efficiency for a USC (ultra-supercritical pressure pulverized coal-fired power generation) used in a cutting-edge coal-fired power station in Japan is about 40%. A commercial machine using the "Integrated Coal Gasification Combined Cycle (IGCC)" could improve the generating efficiency to about 46%, reducing the amount of CO2 emissions about 15% compared to the USC. Furthermore, if we can realize the "Integrated Coal Gasification Fuel Cell Combined Cycle (IGFC)," the ultimate high-efficiency coal-fired power generation that combines IGCC with a fuel cell, then the generating efficiency of a commercial plant could reach 55%, reducing the amount of CO2 emissions about 30% compared to the USC.
* Values for generating efficiency are sending-end, high-grade heating value-based (HHV).