monofuel

Monofuel is a term used in energy and propulsion to describe a fuel that consists of a single chemical species or a nearly pure substance used as the sole energy source in a system. It is contrasted with dual-fuel or multi-fuel systems that blend two or more fuels to adjust properties such as ignition, flame characteristics, or energy density. In practice, monofuels are chosen when predictable combustion behavior and simple fuel handling are important.

Examples and contexts vary by application. Common monofuels include methane in natural gas engines, hydrogen in fuel cells or hydrogen-using combustion engines, propane or kerosene in specific heating or propulsion applications, and methanol in certain microturbine or fuel-cell setups. In each case, the fuel is used as the primary energy source without intentional blending with other fuels.

Advantages of monofuels include simpler fuel management and storage, reduced risk of phase separation or incompatibilities from fuel blends, and often more straightforward engine or system calibration within a defined operating envelope. They can also simplify supply chains in remote or specialized environments where a single fuel is readily available.

Disadvantages include a narrower operating range of performance compared with blended fuels, greater sensitivity to impurities that can affect emissions or longevity, and less flexibility to optimize for varying conditions. Safety and handling considerations are also important, given the properties of pure fuels and their storage requirements.

See also: fuel, energy density, combustion.