Integrated gasification combined cycle (IGCC)

In the initial phase of IGCC, solid fuels undergo a process known as gasification. In this process, the fuel is exposed to a controlled amount of oxygen under high temperatures and pressures, converting it into a mixture of hydrogen and carbon monoxide known as “synthesis gas” or “syngas”. Importantly, the impurities in this syngas such as sulfur and mercury are removed through a cleaning process, ensuring that the gas that is finally burned is significantly cleaner than it would be in conventional power plants.

In the second phase, the clean syngas is fed into a gas turbine, generating power. The hot exhaust gases from the gas turbine are then used to produce steam, which in turn powers a steam turbine to generate additional electricity. Both these processes, the gas turbine cycle and the steam cycle, make up the “combined cycle” part of IGCC. By using waste heat from the gas turbine to produce steam, this technology is incredibly efficient and reduces the total amount of fuel needed for power generation.

The Integrated Gasification Combined Cycle is a ‘green’ technology because it has the potential to significantly cut the emissions associated with burning coal, including nitrogen oxides, sulfur dioxide, and particulates. IGCC also produces less carbon dioxide per unit of output than conventional coal-burning power plants. Moreover, IGCC provides an easier way to capture and store carbon dioxide emissions compared to other coal power technologies, a process known as carbon capture and storage (CCS), potentially bringing it closer to a zero-emission technology.