International Journal of Coal Geology, Vol.153, 28-36, 2016
Differences in bitumen and kerogen-bound fatty acid fractions during diagenesis and early catagenesis in a maturity series of New Zealand coals
Oxygen-bearing functional groups, in particular the carboxylic groups of acids and esters, are mainly responsible for the chemical reactivity of sedimentary organic matter. We have studied kerogen and bitumen fractions from a coalification series from the New Zealand Coal Band covering the rank range from 0.28% to 0.80% vitrinite reflectance. We investigated the composition of fatty acids separated from the bitumen, and compared this to the distribution of kerogen-bound fatty acids (esters) obtained after selective chemical degradation of the macromolecular organic matter. We found remarkable differences in the fatty acid composition between bitumen and kerogen-bound acids, both in the short (