An alternative to achieving efficiency improvements in conventional pulverized coal-fired power stations is through the use of gasification technology. IGCC plants use a gasifier to convert coal or other hydrocarbon feedstock into gaseous components by applying heat under pressure in the presence of steam. In Integrated Gasification Combined-Cycle systems, the syngas is cleaned of its hydrogen sulfide, ammonia and particulate matter and is burned as fuel in a combustion turbine (much like natural gas is burned in a turbine).
The IGCC process 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. The process, which is used in countries like the UK, supposedly creates less sulfur gas due to it being “cleaned” by burning the gasses with either oxygen or air. While the process is said to be better for the environment than ordinary coal or fuel oil plants, it still results in creating gasses that contribute to global warming.