Technology Research Area:

Integrated Gasification Combined Cycle

What is integrated gasification combined cycle, and what does it have to do with TVA's mission?

Integrated gasification combined cycle — coal gasification — breaks coal down into its basic chemical ingredients. The process exposes coal to steam and oxygen under high temperatures and pressures. Chemical reactions set in motion by these conditions result in a mixture of carbon monoxide, hydrogen and other gases that is collectively called syngas.

Sulfur is removed from the syngas, and the cleaned syngas is burned in a gas turbine to produce electricity. Burning syngas produces less than half the sulfur dioxide, nitrogen oxides, mercury and particulate matter produced by a typical coal-fired plant. This cleaner fuel could one day help TVA produce cleaner power from coal.

What is TVA doing about it?

TVA is investigating the use of coal gasification to provide syngas for gas-fired turbine power generation.

What are the possibilities for coal gasification?

Burning syngas not only produces lower levels of pollutants than traditional coal-fired power generation, but emissions of carbon dioxide (CO2), which contribute to global warming, could potentially be captured using much less energy than that required for the capture of CO2 from conventional coal-fired plants.

The fuel efficiency of syngas generation could possibly be boosted 50 percent or more using new technologies such as fuel cells and the ion transfer membrane.

Syngas-fueled combined-cycle technology competes with combined-cycle technology fueled by natural gas and could one day be cost competitive when natural gas prices are higher than normal.