September 23, 2022

Natural hydrogen from sedimentary organic matter

It is said that natural molecular hydrogen (H2) has the potential to become the most important renewable energy source of the future. Most attention is currently focussed on inorganic sources of H2, and we are the very beginning of the long road to development, but what about sedimentary organic matter? Can it also be considered a viable potential feedstock for natural molecular hydrogen (H2)? There are after all 557 sedimentary basins, many with established hydrocarbon production infrastructures.

We have studied overmature tracts of the Songliao Basin (China) and the Cooper Basin (Australia) and concluded that the yield of generated H2 per rock volume closely resembles that of economic shale gas in United States shale gas provinces! Good news indeed.  We have also devised a new kinetic modelling protocol for H2 generation that can readily be employed to reevaluate deep exploration acreage. We are busy presenting our findings at workshops in Vienna and Perth in 2023, and two papers were published last year. Check them out (Horsfield et al., 2022; Mahlstedt et al., 2022).

Enlarge the figure "Energy Gas Kinetics Summary (3K/my)". This shows the range of reactions taking place during progressive subsidence. The kinetics for late gas and hydrogen generation are not sensitive to OM type. The reactions occurring during catagenesis are highly sensitive.

Horsfield, B., Mahlstedt, N., Weniger, P., Misch, D., Vranjes-Wessely, S., Han, S. & Wang, C. (2022) Molecular hydrogen from organic sources in the deep Songliao Basin, P.R. China. International Journal of Hydrogen Energy, 47,16750-16774.

Mahlstedt, N., Horsfield, B., Weniger, P., Misch, D., Shi, X., Noah, M. & Boreham, C.J. (2022) Molecular hydrogen from organic sources in geological systems. Journal of Natural Gas Science and Engineering 105, 104704.