From waste to a solid mineral: a new technology that captures CO2 from the atmosphere and cleans up the planet

Carbon Capture 101


Large amounts of carbon dioxide (CO2) are released into Earth’s atmosphere when we do things like burn fossil fuels and produce cement. CO2 creates a heat-trapping blanket across our entire atmosphere, meaning that as our activities release more and more CO2, the trapped heat accumulates, and Earth becomes warmer and warmer. While some CO2 is absorbed in the soil and ocean, too much has detrimental effects. And because human activities have emitted CO2 past levels which can be managed by nature, additional technology that captures CO2 directly from the ocean and from the atmosphere has become necessary to help eliminate the growing dangers of continuously increasing CO2 (and other greenhouse gas) emissions.

45% of CO2 emissions stay directly in the atmosphere, contributing to the continued warming of our planet.


One technology-facilitated means of carbon sequestration is through direct air capture (DAC). This method removes atmospheric CO2 molecules right from the air. But traditional DAC technology has one significant shortcoming: it requires a lot of energy and is thus not effective at increasing the net sequestration of CO2 (i.e. it does not remove significantly more carbon from the air than it adds).

Alternatively, Earth RepAIR’s distributed direct air capture (DDAC) technology operates at ambient conditions, meaning it does not have to be heated or pressurized, drastically reducing energy usage, emissions, and costs, and increasing the net sequestration of CO2.

DDAC is just one component of a two-part system. The other is a rapid mineral carbonation (REACT) process that converts the captured CO2 into a stable, solid mineral by carbonating alkaline mineral residue from processed industrial waste materials.

“In essence, we’re converting carbon dioxide from the air into carbonate minerals that can be upcycled into construction materials, all under ambient conditions.” –Bu Wang


Coal-fired power plant produces coal ash waste stored in coal ash pond, which leaches toxins in the soil and water of nearby community

Industrial waste—like coal ash, steel slag, and cement kiln dust—can pollute the air, waterways, soil, groundwater, and drinking water in nearby communities when it’s disposed of in surface impoundments, landfills, or nearby waterways. This is a big problem: coal ash, for example, is the second largest waste stream in the U.S. after municipal garbage.

Utilizing landfilled mineral waste materials from decades of industrial operations enables Earth RepAIR to sustainably reach an unprecedented scale of CO2 sequestration. Not only can the carbonate residue recovered from this waste be used to reliably store CO2 for more than 100 years, but reducing the volume of waste helps curb further pollution, improving the health and safety of communities near waste sites.

As an added benefit, one of its potential uses may be as a supplementary cementitious material. This could be significant: cement is the main bonding agent in concrete, which makes up the majority of the world’s roads, bridges, dams, buildings, and other structures.