The assay of particular coal from Illinois is as follows by mass: 67.40 percent carbon (C), 5.31 percent hydrogen (H2), 15.11 percent oxygen (O2), 1.44 percent nitrogen (N2), 2.36 percent sulfur (S), and 8.38 percent ash (noncombustibles). What are the higher and lower heating values of this coal? The heating value of sulfur is 9160 kJ/kg. Note: The combustible constituents in the coal are carbon C, hydrogen H2, and sulfur S. The heating value of sulfur is given to be 9160 kJ/kg. The higher and lower heating values of hydrogen are 141,800 kJ/kg and 120,000 kJ/kg, respectively, and the heating value of carbon is 32,800 kJ/kg Note that if the combustion of a fuel does not yield any water in the combustion of gases, the higher and lower heating values are equivalent for that fuel.