Syngas (from synthesis gas) is the name given to fuel gasses of varying composition that are generated in coal gasification and some types of waste-to-energy facilities.

Syngas consists primarily of carbon monoxide and hydrogen, and has less than half the energy density of natural gas. Syngas can be produced from natural gas as follows:

 CH4 + H2O ==> CO + 3 H2

These gasses are combustible, and are often stored to be burned as a fuel source.

For the most part, the ammount of synthetic gas produced in a waste to energy facility is only enough to keep the plant operating.

Coal gasification processes[1] (e.g., the water gas process) are reasonably efficient and were used for many years to manufacture illuminating gas for gas lighting, before electric lighting became widely available.