An
integrated gasification combined cycle (
IGCC) is a technology that uses a high pressure gasifier to turn
coal and other carbon based fuels into pressurized gas—synthesis gas (
syngas). It can then remove impurities from the syngas prior to the power generation cycle. Some of these pollutants, such as
sulfur, can be turned into re-usable byproducts. This results in lower emissions of
sulfur dioxide, particulates,
mercury, and in some cases
carbon dioxide. With additional process equipment, a
water-gas shift reaction can increase gasification efficiency and reduce
carbon monoxide emissions by converting it to carbon dioxide. The resulting carbon dioxide from the shift reaction can be separated, compressed, and stored through sequestration. Excess heat from the primary combustion and syngas fired generation is then passed to a
steam cycle, similar to a
combined cycle gas turbine. This process results in improved thermodynamic efficiency compared to conventional pulverized coal.