TY - JOUR
T1 - Flash pyrolysis of kerogens from algal rich oil shales from the Eocene Huadian Formation, NE China
AU - Zhang, Z.
AU - Volkman, J.K.
AU - Greenwood, Paul
AU - Hu, W.
AU - Qin, J.
AU - Borjigin, T.
AU - Zhai, C.
AU - Liu, W.
PY - 2014
Y1 - 2014
N2 - The hydrocarbon composition of the kerogen fractions of two samples (HD-20 and HD-21) from oil shale layer 4 in the Eocene Huadian Formation, NE China were investigated by analytical flash pyrolysis (650°C/10s) followed by gas chromatography-mass spectrometry (Py-GC-MS). Organic petrography showed that the two kerogens were almost entirely derived from algal remains but contained very different algal maceral compositions, with 40% of the macerals in HD-20 being of macroalgal origin that were not present in HD-21. Py-GC-MS yielded high concentrations of n-alkanes from both kerogens, but with different molecular weight profiles due to the different algal contributors to the two kerogen samples. The hydrocarbon pyrolysates generated at 650°C from HD-21 in which the green microalga Botryococcus braunii was identified showed a higher proportion of longer chain alkanes and alkenes presumably from cracking of the botryococcus algaenan. We also identified a C40 monoaromatic lycopane derivative, which was absent in the HD-20. The high hydrocarbon potential of both kerogens can be attributed to common microalgal sources, whereas the macroalgae, which is abundant in HD-20, makes only a minor contribution to the hydrocarbon products.
AB - The hydrocarbon composition of the kerogen fractions of two samples (HD-20 and HD-21) from oil shale layer 4 in the Eocene Huadian Formation, NE China were investigated by analytical flash pyrolysis (650°C/10s) followed by gas chromatography-mass spectrometry (Py-GC-MS). Organic petrography showed that the two kerogens were almost entirely derived from algal remains but contained very different algal maceral compositions, with 40% of the macerals in HD-20 being of macroalgal origin that were not present in HD-21. Py-GC-MS yielded high concentrations of n-alkanes from both kerogens, but with different molecular weight profiles due to the different algal contributors to the two kerogen samples. The hydrocarbon pyrolysates generated at 650°C from HD-21 in which the green microalga Botryococcus braunii was identified showed a higher proportion of longer chain alkanes and alkenes presumably from cracking of the botryococcus algaenan. We also identified a C40 monoaromatic lycopane derivative, which was absent in the HD-20. The high hydrocarbon potential of both kerogens can be attributed to common microalgal sources, whereas the macroalgae, which is abundant in HD-20, makes only a minor contribution to the hydrocarbon products.
U2 - 10.1016/j.orggeochem.2014.08.004
DO - 10.1016/j.orggeochem.2014.08.004
M3 - Article
SN - 0146-6380
VL - 76
SP - 167
EP - 172
JO - Organic Geochemistry
JF - Organic Geochemistry
ER -