Solid fuels are contrasted with gaseous fuels and liquid fuels. Solid fuel is used to burn and produce energy through combustion and exchange that heat through cauldron boilers in to water. There are various types of solid material that are used as solid fuel.
Here are some of most common solid fuels:
coal,
wood,
wood pellet,
biomass, peat,
hexamine fuel tablets
grains.
Solid fuels have been used by human for years to create fire, to warm homes or to heat water. Coal is still used in generating electricity today as well as producing hot water in multi fuel boilers. Some of the solid fuels are man made and smokeless others can generate smoke and can contribute to smog as well as creating pollution. The advantage of solid fuel is availability, renew-ability, regeneration, lower emissions and cost.