Abstract: The invention describes citric acid esters as heating materials and fuels in stationary and mobile internal combustion engines and also in heating installations. Such propellants and fuels are characterized in particular by the fact that they burn completely without soot or with very little soot, therefore cause distinctly lower emissions of soot or fine dust than known fossil and regenerative fuels such as gasoline, diesel, kerosene, vegetable oils and biodiesel. Citric acid esters can be obtained completely from regenerative vegetable sources and are therefore CO2 neutral.