Secondary fuels are produced to maximize their potential for combustion. Their prominent characteristics are derived from primary fuel using a process of distillation and refining.

These so-called artificial fuels are distributed for both industry and domestic use in solid states (e.g. charcoal) liquid (e.g. gasoline), or gas (e.g. methanol). New methods are producing more environmentally-responsible fuels such as ethanol or sustainable aviation fuel (SAF) that reduce the reliance on fossil fuels.