The integrated gasification combined cycle (IGCC) produces electricity from a solid or liquid fuel. First, the fuel is converted to syngas which is a mixture of hydrogen and carbon monoxide. Second, the syngas is converted to electricity in a combined cycle power block consisting of a gas turbine process and a steam turbine process which includes a heat recovery steam generator (HRSG). The combined cycle technology is similar to the technology used in modern natural gas fired power plants.
Coal based IGCC plants are still not fully commercial. A number of demonstration plants with electric output up to 300 MW have been built in Europe and the US, all with financial support from government. The motivation for pursuing this technology is the potential for better environmental performance at a low marginal cost. This is especially true for mercury removal and CO2 capture. In order to compete with conventional pulverized coal plants under current environmental regulation, the main challenges facing the IGCC technology today are capital cost and availability.