GeoKiln was founded in late 2024. Two Ph. D.s head the company and conducted the webinar. These are technical leader Alexei Tcherniak and chemical engineer Lorna Ortiz. Tcherniak calls the company’s process to engineer, or manufacture, hydrogen in the subsurface via serpentinization of iron-rich rock with applied heat - affordable, scalable, clean, and net zero positive. They call the process Manufactured Subsurface Hydrogen, or MSSH.
The heat injected into the
surface via electrical resistive heaters serves to accelerate a chemical
reaction that is likely already occurring. How much of the iron-rich rock has
already been serpentinized is important since it dictates how much is left over
and available to be serpentinized via GeoKiln’s process. Thus, Tcherniak says
the present goal and concern is de-risking geology.
Ortiz thinks the economics
can work well, with a targeted produced hydrogen price of 1.5 per kg, which
would make it cheaper than grey hydrogen and much cheaper than blue and
especially green hydrogen. Where it is produced is very important as well. The
location of off-takers is important. Early pilots will likely be deployed in
places where there is both existing hydrogen infrastructure and available
off-takers, in addition to favorable geology. Tcherniak thinks that natural
hydrogen exploration can be big, but it is limited to where it can be produced,
and the likelihood of finding big accumulations in favorable places is not
good. Production near the point of use is important for hydrogen since it is
challenging to transport.
Webinar facilitator,
Enverus’s Graham Bain, compares engineered H2 to engineered oil & gas via
fracking and engineered geothermal via EGS and AGS. Tcherniak points
out that sedimentary basins are not important for engineered serpentinization,
so the areas with the highest potential are in areas with little to no oil
& gas production. As far as transferable skills from the oil & gas
industry, geochemistry is an important one.
Some of the challenges of
validating before scaling up include the need to get enough flow to evaluate.
This is dependent on natural fractures in the rock, which is typically olivine.
Once the process is scaled up, there will be a need to evaluate type curves to
determine the estimated ultimate recovery (EUR) of the manufactured hydrogen.
The technology basically
involves building a plant, a hydrogen reactor, in the subsurface. There is a
need to control the chemical reactions, the applied heat, and ultimately H2
production. The tech involves accelerating reactions that are already
happening. The process involves injection wells and producing wells. That will
likely increase costs a bit. Subsurface electrical resistive heaters are
utilized to provide the heat. There will be a search for the most viable economic
way to manufacture the H2. Geology will drive the process. Well spacing needs
to be considered. Pressure management is important. Monitoring is needed. No
water is injected. Heat is injected surgically. No mass is injected, so new
fractures are not propagated. However, I wonder if that could be done in the
future to increase flow to the surface if needed.
Favorable geology is rocks
that contain iron for serpentinization, which involves chemically reducing
hydrogen from water. The presence and availability of fractures is important.
Sulfur-containing minerals such as pyrite are to be avoided for now. If
necessary, they can be managed where present in the future, as they are with
sour gas and oil. How much iron remains in the rock is an important
consideration, or how much has already been serpentinized. Tcherniak notes that
1km to 1.5 km depth is ideal. Shallower is fine since it is cheaper, as is
deeper, if the rock is better.
There was a question about
the ownership of subsurface H2. Orti noted that each state has its own
regulations, which must be navigated for now. Some terms need to be finalized,
such as royalties. It is likely that areas with more favorable regulations will
be prioritized for now.
Responding to a question
about technology readiness, Tcherniak noted that the technology of deploying
heat to help recover hydrocarbons is fully derisked in several successful
projects around the world, but the heaters have yet to be deployed in the
particular geology favorable for hydrogen production via
serpentinization.
After MSSH is validated, it
will be scaled up (drill baby drill). Asked about other possible gases that
might be produced and their potential effects on local drinking water,
Tcherniak noted that pure olivine produces just H and water vapor. However, if
carbonates are present, there could be some CO2 produced, and if pyrite is
present, there could be some H2S produced. He also pointed out that the radius
of stimulation is very constrained, typically 20-30 or so meters. He reiterated
that the process is controllable. He also noted that subsurface heating is also
being explored to enhance CCS. Asked about success 5 years out, he said that
they hoped to have producing projects making significant quantities of H2,
ideally in several countries.
The webinar/podcast was mainly a
discussion, so there were no figures. I got the following graphics from
GeoKiln’s website, Geokiln
- Unlock the Future, which describe the technology, the
challenges, the benefits, and the targeted production costs.
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