Coal gasification is the process of producing
syngas–a mixture consisting primarily of
methane (CH
4),
carbon monoxide (CO),
hydrogen (H
2),
carbon dioxide (CO
2) and water vapor (H
2O)–from
coal and
water, air and/or oxygen. Historically, coal was gasified using early technology to produce
coal gas (also known as "town gas"), which is a combustible gas traditionally used for municipal lighting and heating before the advent of industrial-scale production of natural gas. In current practice, large-scale instances of coal gasification are primarily for electricity generation, such as in
integrated gasification combined cycle power plants, for production of chemical feedstocks, or for production of synthetic natural gas. The hydrogen obtained from coal
gasification can be used for various purposes such as making
ammonia, powering a
hydrogen economy, or upgrading fossil fuels. Alternatively, coal-derived syngas can be converted into transportation fuels such as
gasoline and
diesel through additional treatment via the
Fischer-Tropsch process or into
methanol which itself can be used as transportation fuel or fuel additive, or which can be converted into gasoline by the
methanol to gasoline process. Methane or natural gas extracted from coal gasification can be converted into
LNG for direct use as fuel in transport sector. LNG would fetch good price equivalent to gasoline or diesel as it can replace these fuels in transport sector.