Author: Carlo Carniani – Senior Petroleum Engineer
INTRODUCTION
It is generally acknowledged that hydrogen gas is a promising resource for power production in the next future. Several publications are available reviewing the availability and use of hydrogen sources. While certain methods of hydrogen production are substantially known (e.g. electrolysis) and are expected to expand in the future, the possibility of exploiting native or geologic hydrogen is stil at its infancy. Several authors claim, on the basis of geological arguments, that hydrogen gas of natural origin may be abundant enough to be a significant energy source. The same authors claim that the reason why this resource is not presently available in large quantities might be a consequence of the fact that hydrogen is not actually searched with proper methods. (Zgonnik, 2020)
This possibility has pretty much to do with chemistry: the role of chemical analysis in hydrogen gas discovery is potentially decisive. According to the presently known discoveries, hydrogen gas is associated with other geological fluid sources: for example, geyser-like water sources like in Mali, block 25, Bourakébougou field (“Hydroma Inc. Block 25 Mali,”)).
Chemical analysis performed on site is crucial for identifying the presence of hydrogen and assess it quantitatively.
Moreover, since hydrogen gas is associated with other geological fluids (water, CO2, H2S, Hydrocarbons) a separation issue occurs as well.
Along with separation, gathering may also present different challenges from those the Oil&Gas industry is accustomed to face: rather than a limited number of high rate wells, it is more likely that native hydrogen has to be collected from a high number of very low rate sources.
Another important aspect in geological hydrogen production is storage: apart from long term storage in suitable underground reservoirs, analogously to what is currently happening with natural gas, it is conceivable that intermediate small scale storage steps will be required in an hypothetical future hydrogen gathering network.
A number of promising developments are possible out of recent results from research in materials science and fuel cells development. The purpose of this paper is giving a flavor of the ongoing chemical research on matters which may help in making native hydrogen a widespread energy source in the next future, without pretending of being exhaustive.