Interest in the integrated gasification combined cycle (IGCC) process is based principally on its potential environmental benefits. When the gasifier is supplied by oxygen instead of air, IGCC plant offer the potential to capture relatively pure carbon dioxide (without nitrogen dilution) that could then be sequestered to virtually eliminate greenhouse gas emissions. There are several gasification processes in operation as well as in development. These can be broadly divided into three main categories: fixed bed, moving bed (e.g. fluidised bed) and entrained flow processes.  The table below summaries the typical properties for several gasifiers.

  

In IGCC power plants, the coal is gasified and the off-take gas is combusted in gas turbines to generate electricity. The hot combustion gases are then passed through boilers to produce steam for further power generation or other industrial use. Thermal efficiencies of 45% higher heat value (HHV) or greater have been achieved in such plant. Several full-scale demonstration plants are operating commercially in the USA and in Europe.