Clean Coal Technology

   Coal is widely distributed & abundantly reserved, so it's possible to ensure the stable supply. However, CO2 emission from coal is larger than from other fossil fuels. There's a pressing need to develop the Integrated coal Gasification Combined Cycle (IGCC) plant which is high efficiency & eco-friendly. CRIEPI are developing the coal gasification technology which is key technology of IGCC.

< Basic Flow Diagram of IGCC system >

IGCC system is integrating coal gasification with combined cycle power generation system. In IGCC system, coal is gasified in a gasifier to produce synthetic fuel gas. The fuel gas is burned to operate a gas turbine. Then, high temperature exhaust gas from the gas turbine is sent into the boiler to produce steam that is used to operate a steam turbine.

   Japan has been working on development of a unique air blown IGCC technology. After experiencing the 200t/d pilot plant project successfully, Japanese government and all Japanese electric power companies decided to construct the IGCC demonstration plant using the air-blown gasifier, and Clean Coal Power R&D Co., Ltd. was established in June, 2001 to conduct the demonstration project. The output of the demonstration plant is 250MW, and the capacity of the gasifier is 1,700t/d. The target net thermal efficiency of the demonstration plant is 40.5% (HHV basis). The operation has started in September, 2007.

< Concept of Air-blown Two-stage Entrained Flow Gasifier >

The pulverized coal is pneumatically transported to the combustor and the reductor. The char contained in the product gas is collected and then recycled to the combustor. The gasifying agent (air) is fed into the combustor to burn the pulverized coal and the recycled char at high temperature, so that the coal ash was discharged from combustor as molten slag.

Copyright (C) Central Research Institute of Electric Power Industry