What type of fuels can a boiler typically use?

A boiler can typically utilize a variety of fuels to generate heat and produce steam, which is essential for various industrial and heating applications. The most common fuel types include natural gas, propane, oil, coal, and biomass.

Natural gas is favored for its efficiency and lower emissions compared to other fossil fuels. Propane is also commonly used, particularly in areas where natural gas availability is limited. Oil boilers are widely employed in locations where oil is more accessible or cost-effective. Coal has traditionally been a significant source of fuel for boilers in large power plants, although its use is declining due to environmental concerns. Biomass refers to organic materials, such as wood pellets or agricultural waste, which are utilized as renewable energy sources in some boiler systems.

The other options presented include fuel types that either do not serve as primary fuels for traditional boiler systems or are less common. For instance, nuclear fuel is typically associated with nuclear reactors, and geothermal energy is harnessed through specific systems designed for direct heating or electricity generation, not conventional boilers. Electricity can power electric boilers, but it is not used as a fuel in the same sense as the others listed in the correct answer. Hydrogen is an emerging fuel source but is not widely implemented in traditional boiler systems yet. Lastly