AUSTIN (KXAN) – Salt is one of the most common seasonings/condiments on the planet. Every kitchen has it. For thousands of years, it has been a key ingredient in our civilization and now, University of Texas in Austin researchers say, it could be important to our transition to a cleaner future.
“Historically, salt formations have been associated with oil and gas exploration and production,” said Lorena Moscardelli, director at the State of Texas Advanced Resource Recovery Program at UT’s Bureau of Economic Geology.
In a new paper published last month in Tektonika, researchers with Moscardelli’s team argued for the role salt could play. “I think in the next five years, we will we will start to see this implemented,” Moscardelli said.
Lead author and UT research scientist Oliver Duffy pointed to salt domes in the Gulf of Mexico as an example. “Salt dorms can be 10 or so kilometers tall,” Duffy said. Some can be larger than Mount Everest.
“These salt domes will channel heat from deep in the earth,” Duffy said, making them an excellent source of geothermal power. But that’s not the only role salt could play.
Salt: the ultimate storage system
Salt domes and layers of salt found in other parts of the world, like the Permian Basin in West Texas, have a few unique properties that could make them excellent for storing fuel used in clean energy.
“It also seals. It doesn’t allow fluids to go in,” Duffy said. This means energy companies could drill into salt formations and use them to store gas and liquids, like hydrogen fuel.
“Then when the wind is not blowing, or the sun is not shining, you can tap into that hydrogen and generate power,” Moscardelli said.
By drilling a hole, then adding a little water, scientists can create a void in these deposits.
Different salt formations offer different opportunities
Salt deposits form when oceans evaporate, leaving behind the salt that was once water. Over time, other sediments pile on top of the salt layer. This creates a layer cake-like subsurface, where you’ll have a layer of sand, then a layer of salt, then a layer of clay and so on.
In the Gulf, these individual layers can be brittle. Duffy describes them as a graham cracker crust, while salt acts sort of like “toothpaste.”
As the layers crack, they push down on the salt, which flows upwards sort of like when you squeeze a tube of toothpaste. This motion creates these massive domes.
In West Texas, the layers don’t crack. This means the layers are more distinct.
“For energy purposes, what we have here in the Permian Basin is more extensive area, but much thinner,” said Post-Doctoral Researcher Ander Martinez-Doñate.
Instead of mountain-sized deposits, salt layers in West Texas can be several hundred feet thick. These layers can also be variable in size. “We will be capable of creating more caverns, but they will be smaller,” Martinez-Doñate said.
Complications of salt storage
While salt is currently used for the storage of gasses like helium, which is inert and doesn’t risk a reaction, hydrogen is not. So research is needed to see if anything in the salt deposits could cause a reaction.
According to Martinez-Doñate, other minerals can mix in with the salt deposits. “That’s a big part of the project to analyze all the risks with hydrogen storage. How does hydrogen react with the minerals?”
“The other big question,” Moscardelli said, “Is how microbes can react with hydrogen because microbes love to eat hydrogen.”
These two topics are exactly what the team of researchers are studying at UT’s Bureau of Economic Geology. “We still need to learn a lot. And we still need a lot of support that translates into funding.”
As for using salt in this way, is there any risk of us running out of salt? Moscardelli said no.
“I don’t think we’re running any risk of running out of salt for purposes of energy storage or for any other purposes.”