Learn About Carbon Capture and Storage with the MRCI at COSI

On Saturday, May 7, the MRCI occupied a corner of the Battelle booth at the COSI Big Science Celebration 2022. Battelle, which co-leads the Midwest Regional Carbon Initiative along with the Illinois State Geological Survey, is a “visionary” sponsor/partner of COSI (Center of Science and Industry), a nationally recognized science/discovery center in downtown Columbus, Ohio.

The MRCI experiments centered around the geology of carbon capture and storage, challenging visitors to test their strength against a caprock and encouraging them to create their own Carbon Capture and Storage Rock Kits comprised of two cap rocks, two reservoir rocks, and pyrite and lava rock.

To learn more about the rocks in the Carbon Capture and Storage Rock kits, and to find fun experiments with the specimens – keep reading!

Carbon Capture and Storage Rock Kits

The Earth is made up of different rocks layered on top of each other. Some of these rocks are porous, which means that they have tiny holes in them that let water and air pass through them, and some are non-porous, which means that nothing can get through them. In carbon capture and storage, we look for special formations underground where layers of porous rocks, which we call storage reservoirs, are covered by layers of non-porous rocks, which we call cap rocks. These formations are good places to store gasses like carbon dioxide, which can build up in our atmosphere and cause our planet to get too hot too fast. The gas is pumped underground into the reservoirs and the cap rocks trap it there forever

The rocks in your kit are:


Shale – Cap Rock – Sedimentary rock formed from mineral-rich silt, or mud, deposited on the deep-ocean floor, basins of shallow seas, and river floodplains. It is a relatively impermeable rock, often found atop a salt dome. Most shales occur in big sheets that can be hundreds of feet thick, making it an ideal Cap Rock.


Salt – Cap Rock – Sedimentary rock that is made up almost entirely of halite, a mineral composed of sodium chloride, which is the kind of salt you put on French fries.  But because this rock is dug out of the earth, it contains additional minerals and other things which mean it’s not intended for humans to eat. Salt is formed by the evaporation of oceans that existed on the earth millions of years ago. In the US alone, there are thousands of square miles of salt deposits in the earth, which can reach thicknesses of over 100 feet.


Sandstone – Reservoir Rock – Sedimentary rock consisting of sand and mineral particles cemented together over millions of years. They are very porous and therefore make excellent storage reservoirs for water, oil, and carbon dioxide.


Dolomite – Both Reservoir Rock and Cap Rock – Sedimentary rock composed primarily of the mineral dolomite and formed in marine environments by deposits of lime-rich mud coming into contact with magnesium-right groundwater. Dolomite is porous and makes up approximately two percent of the Earth’s crust and 80% of carbonate rock petroleum reservoirs. Many dolomites have fossils – check yours with a magnifying lens and see how many you can find!

Lava rock
Lava Rock

Lava Rock – Volcanic rock, specifically foamed obsidian, is formed when gasses released in a volcanic eruption penetrate lava, but do not escape before it cools, leaving air pockets behind. These holes are a good example of the pores found in porous rocks.


Pyrite – also known as iron sulfide or “fool’s gold,” is commonly found among  sedimentary rocks, particularly in limestone, sandstone and carbonaceous siltstones or shales. While it looks a lot like gold, pyrite often appears as cubic crystals and is lighter and much harder to scratch.


EXPERIMENT! Use a magnifying glass to look at each rock sample. Which ones have pores? Which ones have other tiny pieces of other rocks in them? Can you see individual grains of sand?

EXPERIMENT! Use a pipette or dropper to put a small drop of water onto your rock specimens and observe what happens. Does the water sink into the rock or stay beaded up on top of it? How long does it take for the rock to absorb the water? The faster the water absorbs into the rock, the more porous it is and the better suited the rock is as a reservoir.

EXPERIMENT! Look at the salt specimen in your rock kit. Does it have a familiar shape? The cubes you see are a great example of crystalline structure, which happens when the individual atoms that make up salt stick together. Is there anything else in your rock kit that has a similar structure? Why do you think it formed that way?

Want to learn how to identify rocks on your own? Check out this great YouTube Video from The Science Mom

Glossary of terms:

Porous – rocks that have tiny holes in them that let water and air pass through them

Non-porous – rocks that do not have any holes or other ways to allow air or water to flow through them

Cap rock – thick layers of non-porous rocks that trap liquids and gasses in underground reservoirs

Reservoir rock – porous layers of rock that can hold liquids and gasses

Storage Reservoirs – special formations underground composed of layers of porous rocks in which gasses, like natural gas and carbon dioxide, and liquids, like water, can be stored.

Sedimentary rock – rocks that are created by the build up of organic materials, like plants and animals, or other rocks that are pressed together over thousands of years. They form close to the earth’s surface.

Climate change – A long-term change in the Earth’s weather patterns caused by the accumulation of too many greenhouse gasses, like Carbon Dioxide, in the Earth’s atmosphere. Climate change can make storms more severe and melt ice deposits that have remained frozen for millions of years.

Carbon dioxide – also known as CO2, is a gas present on the Earth that makes up a small amount of the air humans breathe in, and a large amount of what we breathe out. Trees take in Carbon Dioxide and release oxygen. In addition to coming from humans, Carbon Dioxide is also created when fossil fuels, like the gasoline we use to fuel our cars or the natural gas we use to cook our food, are burned. When too much CO2 accumulates in the Earth’s atmosphere, it can cause the Earth to heat up too fast, too soon. That’s why we are working to remove Carbon Dioxide from the air and store it safely in the ground.

Check out this website from the National Energy Technology Laboratory for more information on Carbon Dioxide.

Additional Learning

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