Sandia studying subterranean storage of hydrogen
11 April 2024
Scientists at Sandia National Laboratories are using computer simulations and laboratory experiments to see if depleted oil and natural gas reservoirs can be used for storing hydrogen. Hydrogen is an important clean fuel: It can be made by splitting water using solar or wind power, it can be used to generate electricity and power heavy industry, and it could be used to power fuel-cell-based vehicles. Additionally, hydrogen could be stored for months and used when energy needs outpace the supply delivered by renewable energy sources.
Hydrogen would be good for seasonal and long-term storage. If you think of solar energy, in the summer you can produce a lot of electricity, but you don’t need a lot for heating. The excess can be turned into hydrogen and stored until winter.
—Sandia chemical engineer Tuan Ho, who is leading the research.
However, hydrogen has a much lower volumetric energy density than carbon-based fuels such as natural gas or propane and is much more difficult to compress, Ho said. This means storing huge amounts of hydrogen in metal tanks on the surface is just not feasible, he added.
Hydrogen can be stored underground in salt caverns, but salt deposits are not widespread across the US, said Don Conley, the manager for Sandia’s underground hydrogen storage work. Therefore, Ho’s team is studying if hydrogen stored in depleted oil and gas reservoirs will get stuck in the rock, leak out, or get contaminated.
Ho’s team recently shared their findings in a paper published in the International Journal of Hydrogen Energy.
First, Ho’s team studied if hydrogen would get stuck in the sandstone or shale that forms the body and seal around many oil and gas reservoirs or leak out. Sandstone is composed of sand-sized grains of minerals and rocks that have been compressed over eons; sandstone has a lot of gaps between particles and thus can store water in aquifers or form oil and gas reservoirs. Shale is mud compressed into rock and is made up of much smaller particles of clay-rich minerals. Thus, shale can form a seal around sandstone, trapping oil and natural gas.
You want the hydrogen to stay where you inject it. You don’t want it to migrate away from the storage zone and get lost. That’s just a waste of money, which is a big concern for any storage facility.
—Tuan Ho
”
Ho’s collaborators at the University of Oklahoma used experiments to study how hydrogen interacts with samples of sandstone and shale. They found that hydrogen does not stay inside sandstone after it is pumped out, but up to 10% of the adsorbed gas got stuck inside the shale sample, Ho said. These results were confirmed by Ho’s computer simulations.
Taking a closer look at a specific type of clay that is common in the shale around oil and gas reservoirs, Ho conducted computer simulations of the molecular interactions between layers of montmorillonite clay, water and hydrogen. He found that hydrogen does not prefer to go into the watery gaps between mineral layers of that kind of clay.
This means that the loss of hydrogen in clay due to getting stuck or moving through it would be tiny, Ho said. This is quite positive for underground storage of hydrogen. These findings on clay were published last year in the journal Sustainable Energy and Fuels.
Additional absorption experiments are being conducted at Stevens Institute of Technology and the University of Oklahoma to confirm the molecular simulation results, Ho said.
Using both experiments and simulation, Ho’s team found that residual natural gas can be released from the rock into the hydrogen when hydrogen is injected into a depleted natural gas reservoir. This means that when the hydrogen is removed for use, it will contain a small amount of natural gas, Ho said.
That’s not terrible because natural gas still has energy, but it contains carbon, so when this hydrogen is burned, it will produce a small amount of carbon dioxide. It’s something we need to be aware of.
—Tuan Ho
Ho’s team, principally Sandia postdoctoral researcher Aditya Choudhary, is currently studying the effects of hydrogen on a depleted oil reservoir and how leftover oil might contaminate or interact with hydrogen gas using both molecular simulations and experiments.
The findings from Ho’s research can be used to inform and guide large field-scale tests of underground hydrogen storage, said Conley, the manager for Sandia’s portion of the Department of Energy Office of Fossil Energy and Carbon Management’s Subsurface Hydrogen Assessment, Storage, and Technology Acceleration project. The SHASTA project plans to conduct such a field-scale test in the future to demonstrate the feasibility of depleted oil and natural gas reservoirs for hydrogen storage, he added.
Additional research is needed to understand how microorganisms and other chemicals in depleted petroleum reservoirs might interact with stored hydrogen, Ho said.
The project is funded by Sandia’s Laboratory Directed Research and Development program.
Resources
Tuan A. Ho, Son T. Dang, Nabankur Dasgupta, Aditya Choudhary, Chandra S. Rai, Yifeng Wang (2024) “Nuclear magnetic resonance and molecular simulation study of H2 and CH4 adsorption onto shale and sandstone for hydrogen geological storage,” International Journal of Hydrogen Energy, Volume 51, Part A, 2024, Pages 158-166, doi: 10.1016/j.ijhydene.2023.11.011
Tuan A. Ho, Carlos F. Jove-Colon and Yifeng Wang (2023) “Low hydrogen solubility in clay interlayers limits gas loss in hydrogen geological storage.” Sustainable Energy and Fuels doi: 10.1039/D3SE00363A
Batteries can cope for short term storage, up to 4 hours or so, they aren't suitable even for overnight.
And for seasonal storage, they have nothing to do with it.
Most of the comparisons between hydrogen and batteries are irrelevant, as they are not remotely comparable in many applications.
So relative efficiencies and so on don't even come into play.
Posted by: Davemart | 11 April 2024 at 02:35 AM
Agree with Davemart that the dichotomy of pitting battery against H2 is wrong, because battery and H2 should be used together, with battery for short-term and H2 for longer term e-storage.
If waste heat is useable, then H2 can also be used to store daily solar energy for use in the evening by local fuel cells or engine whereby the waste heat is collected and used to make hot water for bathing, laundry and dish washing. The local natural gas piping system can be repurposed for H2 and can store several day's worth of H2 without even needing underground storage.
One easy way to investigate and quantitate the extent of H2 loss in a typical natural gas reservoir is to build a reduced-scale model of a typical natural gas reservoir with shale walls and the inside filled with sandstone and apply appropriate degree of moisture and typical microbes. Then H2 will be pumped in and recovered after a while, with the percentage of in and out quantitated carefully.
Posted by: Roger Pham | 11 April 2024 at 05:29 PM
Hi Roger.
It is difficult for any of us to hit an even handed stance, and my issue is that many on the subject of the use of hydrogen, just like nuclear before it, seem to have adopted such a locked in stance that objective assessment is impossible, as they are arguing a case, not realistically assessing.
This is the sort of thing I mean:
https://www.hydrogeninsight.com/policy/hydrogen-pipeline-network-would-cost-customers-87-more-to-use-than-existing-gas-grid-study/2-1-1623816
I do not wish to argue against the figures they present, nor is it necessary to do so to demonstrate that their assessment is false, although after that is noted questions must arise about which how they arrived in detail at those figures.
They charge the carrying costs of the current gas network to a revamped hydrogen network, which at first seems fair enough.
So what would happen to those costs if the gas network was not used, and new electric infrastructure installed instead?
The answer is of course that the current gas network would be a total write off, and in addition there would be both costs for whatever was needed to make it safe and to install vast new electric infrastructure, for long distance in Germany substantially underground, as they are not willing to have the countryside ruined by pylons and their construction.
So although the costs of a hydrogen network might be higher than current, that does not mean that it might not be by far the cheapest option.
This is fake accounting.
They also assume that the hydrogen is used in the most inefficient way possible, by burning it in boilers.
Obviously should fuel cells which are 90% plus efficient in electric plus heat be used, then the figures they present are a nonsense.
There would therefore appear to be two possible choices, should my analysis be accepted.
The writer of the piece is either entirely incompetent, or is knowingly misrepresenting in an attempt to knock a technology they dislike.
Unfortunately I have encountered a lot of this quasi religious 'from first principles' stuff which adopts a conclusion, ie no hydrogen, and argues backwards from this to make a rationale.
It is second only to the nuclear arguments of my youth in this respect.
Posted by: Davemart | 12 April 2024 at 02:11 AM