Relationships Between Specific Gravities and Higher Heating Values of Petroleum Components

The aim of this study was to estimate mathematical relationships between higher heating value (HHV) and specific gravity of petroleum fuels. The HHV is an important property defining the energy content of petroleum related fuels. The specific gravities of petroleum fuels generally range from 0.56 to 0.92 (based on the specific gravity of pure water is 1 at 15.6°C). There is high regression between specific gravity and HHVs for petroleum fuels. An increase in specific gravity from 0.56 to 0.92 for petroleum fuels decreases the HHVs from 50.4 to 41.6 and the decreases are highly regular. The HHV (MJ/kg) of the petroleum sample as a function of the specific gravity of petroleum constituent can be calculated from:For aliphatics and alicyclicsHHV = –21.63SG + 62.88For aromaticsHHV = –2.67SG + 39.23According to the two equations, higher heating value of petroleum is a function of the specific gravity of petroleum constituent. The HHVs (MJ/kg) of the crude oil samples as a function of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and sulfur (S) can be calculated from the following equation:HHV = 31.6(C) + 142.3(H) + 30.8(S) – 15.4(O) – 14.5(N)