What are advantages of gaseous fuels over solid and liquid fuels?

1. They can be carried easily through pipelines to the point of use, so there is no handling or storage labour.
2. They mix intimately with air, so combustion is complete with only a small excess of air. Little CO or smoke is formed.
3. No ash or residue is left after burning.
4. Combustion is easy to start, stop and control, and the flame length and temperature can be adjusted.
5. They have high thermal efficiency and a high calorific value per unit mass. They can be preheated using waste heat, which saves fuel.
6. They burn cleanly, with no smoke or soot, so pollution is low.
7. There is no spontaneous combustion of the kind seen with stored coal.

Limitations: they need large storage tanks, and a leak is a fire or explosion hazard.