Hydrogen is the lightest and most abundant element in the universe and is currently a popular topic in the energy industry news. H2 is considered part of the energy mix as an energy carrier, used to transport and store energy from a primary source. A dive into the topic, using the Datapages Archives, shows that in early petroleum journals the word “hydrogen” appears primarily in reference to hydrogen sulfide (H2S) which is a naturally occurring gas that sours crude oil. The references to hydrogen as a source of energy (using fuel cells) did not begin until the mid-20th century.
A 1973 article in the Shale Shaker Digest by Dean A. McGee of Kerr-McGee Corp. describes the energy problem (as seen 52 years ago) “… the decade of the 1970’s promises to be very difficult for the energy businesses as the people of the United States demand the attainment of two vital national goals that are not entirely compatible – a clean environment and an abundant supply of low-cost energy.”
Many energy producers believe that natural hydrogen is an opportunity to provide cheap, low-carbon energy. However, the cost of the electrolyzers and the problems of storing hydrogen have slowed commercialization. The Archives can be a great resource for the exploration of natural hydrogen. The natural hydrogen system is based on ultra mafic rocks, so a quick review of the Archives shows more than 600 articles referencing “peridotite,” almost 200 articles for “dunite”, 669 articles for “serpentinite,” and more than 2,000 articles on “ultra-mafic.” There are almost 7,000 references to hydrogen alone. All of these are peer-reviewed articles, and this isn’t counting the listings for abstracts nor Search and Discovery.
There are four potential storage deposits for underground hydrogen storage: (1) salt caverns, (2) deep aquifers, (3) depleted oil and gas reservoirs, and (4) hard rock caverns. There are knowledge gaps concerning the timescale of hydrogen migration (i.e. days or years) which is controlled by a wide range of lithological and environmental variables (see accompanying image). The gaps will need to be filled before commercial production is successful.
The Hydrogen Rainbow
The industry uses color names to identify the type of hydrogen and the amount of greenhouse gases that are being released:
- Green H2: Produced by using clean electricity from surplus renewable energy sources, such as solar or wind power, to electrolyze water.
- Blue, low-carbon H2: The steam reforming process doesn’t avoid the creation of GHG’s, but carbon capture and storage is used.
- Grey: Created from natural gas or methane using steam methane reformation but without capturing the GHGs made in the process. Grey H2 is essentially the same as blue H2, but without the use of CCS.
- White (or Gold): A naturally occurring, geological H2 found in underground deposits
- Pink: Generated through electrolysis powered by nuclear energy
- Yellow: A relatively new term for H2 made through electrolysis using solar power
- Orange: A theoretical possibility for hydrogen generated in-situ in the sub-surface
The main advantage of white or gold hydrogen is the cost over the other forms. Grey costs less than $2 per kilogram, with green costing three times more. At present, Canada-based Hydroma extracts white H2 at approximately 50 cents per kilogram, while in Spain and Australia the project goals are about a dollar per kilogram.
Ongoing Hydrogen Extraction Operations
It was an accidental discovery, during the drilling of water well, that detected an underground accumulation of H2 that led to the one and only operational white hydrogen project, located in Bourakebougou, Mali. The well produces about five tons of H2 per year. The small-scale project has been in operation for a decade and powers the local village.
In Australia, the company Gold Hydrogen Limited has demonstrated the feasibility of drilling successful exploration wells to explore for naturally occurring hydrogen. Using modified drilling techniques, and special mud gas monitoring and sampling tools, they found natural hydrogen and helium within the Cambrian Parara Limestone, the Kulpara Formation and in the granitic basement. Hyterra has recently announced high concentrations of hydrogen in wells specifically drilled for hydrogen along the Mid-Continent Rift in the Central United States.
Currently, other countries exploring for H2 include the United States, France, Albania, Colombia and South Korea.
To learn more about H2 exploration visit the Datapages Archives. The collections from Australian Energy Producers (formerly APPEA), GeoExpro, and PESA are especially helpful.