Structure of Middle Distillate Fuels: On the Atomic Carbon and Hydrogen to Carbon Ratio at Alpha Position to Aromatic Rings

The alkyl, naphthenic, or total carbon atoms of the functional groups at alpha position to aromatic rings and their hydrogen to carbon ratio are some of the important parameters for structural analysis of fossil fuel products. The Brown-Ladner concept for the atomic hydrogen to carbon ratios at alpha, and beta and gamma positions is over twenty-five years old and, in spite of its very approximate nature, is still being used by both Proton and Carbon-13 Nuclear Magnetic Resonance analysts. In this paper, we present a number of novel formula-structure relationships for precise determination of different carbon atom types at alpha position to aromatic rings and the average number of hydrogens per alpha-carbon.