Distribution of light alkanes in the reaction of graphite hydrogenation at pressure of 0.1–7.8 GPa and temperatures of 1000–1350°C

ABSTRACT

We studied the effect of pressure and temperature on the hydrocarbon (HC) chain length distribution and total amount of HCs in the reaction of direct graphite hydrogenation at pressures of 0.1–7.8 GPa and temperatures of 1000–1350°C. An increase in pressure was found to lead both to an increase in the absolute yield of HCs due to direct graphite hydrogenation and to chain elongation of HC products. Light alkanes predominate among HCs in the entire studied range of P–T parameters. However, their concentration in quenched fluids increases as pressure is elevated, from less than 10 rel.% at 0.1 GPa to more than 40–50 rel.% at P ≥ 3.8 GPa. Methane is actually the only light alkane among reaction products at 0.1 GPa and 1000°C, while it is a minor component at 7.8 GPa and 1350°C. The most stable alkane at pressures above 3.8 GPa is ethane (C₂H₆).

KEYWORDS:

• HPHT experiment
• hydrocarbons
• graphite hydrogenation
• gas chromatography–mass spectrometry

Acknowledgements

We thank Yury Borzdov and Alexander Khokhryakov for assistance throughout the study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The study was supported by a grant 16-17-10041 from the Russian Science Foundation. IHPV experiments at 0.1 GPa were supported by program 19 of the Presidium of the Russian Academy of Sciences.