
147Fuels
8.4.1 Chemical Composition
All liquid fuels mainly consist of mixtures of hydrocar-
bon compounds with a higher ratio of carbon to hydro-
gen than that of gaseous fuels, fuel nitrogen (0.1%–2.2%
by weight), sulfur (0.2%–3% by weight), and ash (min-
erals). The hydrocarbons are complex materials, which
are difcult to analyze; therefore, it is common practice
to measure an ultimate chemical analysis and several
physical properties rather than to nd their chemical
structures.
An ultimate chemical analysis refers to an analysis
routine that includes carbon, hydrogen, nitrogen, sulfur,
and ash. It may be appropriate to request analyses for ...