The new technique turns ordinary rocks into carbon machines

Of all greenhouse gases to warming the planet, human activity is released into the atmosphere, carbon dioxide is the most significant emissionsS As such, experts suggest that in addition to drastically reducing the use of fossil fuels, we must actively remove carbon dioxide (CO2) from the atmosphere. However, what is known as carbon capture technology is usually expensive and/or energy intense and requires solutions for carbon storage.

Now researchers at Stanford University have suggested a surprising practical strategy: make the rocks do it for us.

They are not joking. Stanford chemists Matthew Kanan and Jukuan Chen have developed a process that uses heat to convert minerals into materials that absorb CO2 – constantly. As described in a a exploration Posted on Wednesday in the magazine NatureThe process is practical and inexpensive. In addition, the many useful scales of Canan and Chen could meet the needs of a common agricultural practice by hitting two birds with one stone.

“The earth has an inexhastible supply of minerals that are capable of removing CO2 from the atmosphere, But i Just Don’s React Enough on Their Own to Counter Grehou Author of the Study, Said in Stanford statementS “Our work solves this problem in a way that we think is a unique scale.”

For decades, scientists have been studying ways to accelerate the natural absorption of CO2 of some rocks, a process called atmospheric influences that can take hundreds, if not thousands of years. Kanan and Chen seem to have cracked the code, turning common slow falling minerals called silicates into fast -standing minerals.

“We planned to activate new chemistry to activate inert (not chemically reactive) silicate minerals through a simple ion exchange reaction,” Chen explained. Ions are atoms or groups of atoms with electric charge. “We didn’t expect it to work as well as he did.”

Canan and Chen are inspired by the production of cement, where a furnace or furnace converts a limestone (sedimentary) into a reactive compound called calcium oxide, which is then mixed with sand. Chemists reproduced this process, but exchanged sand for a material called magnesium silicate. Magnesium silicate contains two minerals, which with heat exchanged ions and turn into magnesium oxide and calcium silicate: minerals that quickly.

“The process acts as a multiplier,” Kanan said. “You take a reactive mineral, calcium oxide and magnesium silicate, which is more or less inert, and generate two reactive minerals.”

To test their results, Kanan and Chen expose wet calcium silicate and magnesium air oxide. They have become carbonate minerals – the result of atmospheric influences – no weeks to months.

“You can imagine the spread of magnesium oxide and calcium silicate on large ground areas to remove CO2 from the surrounding air,” Kanan said. “An exciting application we are testing now is to add them to agricultural soil.” This application can also be practical for farmers who add calcium carbonate to the soil when it is too acidic: a solution called a restriction.

“Adding our product would eliminate the need for limitation, as both mineral components are alkaline (basic, unlike acid),” Kanan explained. “In addition, such as calcium silicate atmospheric conditions, it releases silicon to the soil in the form that plants can occupy, which can improve the yield and resistance of crops. Ideally, farmers would pay for these minerals because they are useful for farm productivity and soil health – and as a bonus, there is carbon removal. “

Approximately one tonne of magnesium oxide and calcium silicate can absorb one tone CO2 from the atmosphere – and this assessment reports CO2 emitted by the furnaces themselves, which still require less than half the energy used in other carbon capture technologies.

However, the scaling of this solution to an impactful level will require millions of tons of magnesium oxide and calcium silicate, annually. Nevertheless, Chen points out that if the evaluations of the natural reserves of magnesium silicates such as olivine or serpentine are accurate, they would be sufficient to remove the entire atmospheric CO2 from the person, and then some. In addition, silicates can be restored from paste (mining residues).

“Society has already figured out how to produce billions of tons of cement a year, and the cement furnaces have been working for decades,” Kanan said. “If we use this knowledge and designs, there is a clear way to move from the discovery of a laboratory to the removal of carbon on a meaningful scale.”