Wednesday, November 26, 2008
Integrated Gasification Combined Cycle: The Future?
Integrated Gasification Combined Cycle (IGCC) can help provide electricity from coal in an environmentally sustainable way. IGCC partially burns coal to generate gas. IGCC can lower air emissions, lower water usage and produce less solid waste. Coal gasification takes place in the presence of a controlled 'shortage' of air/oxygen. The synthesis gas (syngas) is cleaned and then burned with either oxygen or air, generating combustion products at high temperature and pressureBut only two coal fired power plants in the country currently use IGCC technology.
IGCC uses a combined cycle format with a gas turbine driven by the combusted syngas, while the exhaust gases are heat exchanged with water/steam to generate superheated steam to drive a steam turbine. Using IGCC, more of the power comes from the gas turbine. Typically 60-70% of the power comes from the gas turbine with IGCC.