Coal Gasification – UPSC Prelims

Coal Gasification:
  • Process: Coal gasification is a process in which coal is partially oxidised with air, oxygen, steam or carbon dioxide to form a fuel gas.
  • This gas is then used instead of piped natural gas, methane and others for deriving energy.
  • In-situ gasification of coal – or Underground Coal Gasification (UCG) – is the technique of converting coal into gas while it is still in the seam and then extracting it through wells.
  • Production of Syngas: It produces Syngas which is a mixture consisting primarily of methane (CH4), carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2) and water vapour (H2O).

  • Applications:
    • Steel companies typically use coking coal in their manufacturing process. Most of the coking coal is imported and is expensive.
    • To cut costs, plants can use syngas, which comes from coal gasification plants in the place of coking coal.
    • It is primarily used for electricity generation, for the production of chemical feedstocks.
    • The hydrogen obtained from coal gasification can be used for various purposes such as making ammonia, powering a hydrogen economy.
    • Methane or natural gas extracted from coal gasification can be converted into LNG for direct use as fuel in the transport sector.
  • Concerns:
    • Coal gasification is one of the more water-intensive forms of energy production.
    • There are concerns about water contamination, land subsidence and disposing of waste water safely.
    • Coal gasification actually produces more carbon dioxide than a conventional coal-powered thermal power plant.
    • The syngas process converts a relatively high-quality energy source (coal) to a lower quality state (gas) and consumes a lot of energy in doing so.