Spiritus | Expert voices: Spiritus CEO on the future of DAC

Expert voices: Spiritus CEO on the future of DAC

Photo illustration: Gabriella Turrisi/Axios. Photo: courtesy of Spiritus

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Founders need to be maniacal about developing the best solution for their market, says Spiritus CEO Charles Cadieu.

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Why he matters: Cadieu just led his Los Alamos, N.M.-based direct air capture startup out of stealth mode this week with backing from Silicon Valley venture firm Khosla Ventures and a carbon removal purchase deal with heavyweight Frontier.

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This interview was edited for length and clarity.

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On the DAC market:

"It's an incredibly exciting time...The whole project financing world is starting to see this as becoming very viable with these advanced purchases. And that's going to be a critical linchpin to really scale this market, which we saw with solar and wind. Economics are going to be the major driver here. And there will be consolidation. I could imagine maybe a small handful of less than five techniques."

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What was the big story in climate tech this week?

"Let's go with our news. It's something dear to us, and something we've been waiting to tell the world for some time."

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What is going undernoticed in climate tech right now?

"The DAC and sequestration incentives within the IRA. 45 Q gets to $180 per ton that the federal government is paying through either direct payment or tax incentive. That can really demonstrate removal for sub $100, as we're planning to at Spiritus."

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What is one tip for climate tech founders?

"My approach is to really have the best solution in the market. I think if you're not somewhat maniacally going for that best solution, it's going to be hard to win over the long term."

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What was your first job?

"In the summers, I would work in my dad's physics lab. I would do work on solid state physics and materials development for magnetic thin films. I tried to make a device called a spin valve. That was cutting my teeth on real agony and lots of hours of futility. But that also kind of developed my perseverance as to how to see deep tech through."

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In three-ish words, how would you change the climate tech landscape?

"Rally behind solutions."

Rewind.earth

Biomass carbon removal and storage

Tel Aviv, Israel

R&D

Rewind.earth uses cranes off of boats to sink agricultural and forest residues to the oxygenless bottom of the Black Sea, the largest anoxic body of water on Earth. Oxygenless water dramatically slows biomass decomposition. The lack of living organisms in the Black Sea limits any potential ecosystem risks. This process allows for affordable and environmentally safe carbon removal.

Carboniferous

Biomass carbon removal and storage

Houston, TX, US

R&D

Carboniferous sinks bundles of leftover sugarcane fiber and corn stover into deep, salty, oxygenless basins in the Gulf of Mexico. The lack of oxygen in these environments–and therefore absence of animals and most microbes–slows the breakdown of biomass so it is efficiently preserved and stored durably in ocean sediments. The team will conduct experiments to determine the functional stability of sunken biomass as well as the interaction with ocean biogeochemistry.

Vycarb

Ocean alkalinity enhancement

Brooklyn, NY, US

58 tons

Vycarb uses a reactor to add limestone alkalinity to coastal ocean water, resulting in the drawdown and storage of atmospheric CO₂. Their dissolution system has a novel sensing apparatus that base tests water, dissolves calcium carbonate, and doses alkalinity into the water at a controlled amount safe for dispersion. Their closed system makes it easier to measure the amount of dissolved alkalinity added and CO₂ removed.

Arbon

Direct air capture

New York, NY, US

173 tons

Arbon uses a 'humidity-swing' process to capture CO₂ from the air. The sorbent binds CO₂ when dry and releases it when wet. This process uses less energy than approaches that rely on changing temperature and pressure to release CO₂. The sorbent’s ability to bind CO₂ has been shown to remain stable over thousands of cycles. Both of these innovations could reduce the cost of DAC.

Vaulted

Biomass carbon removal and storage

Houston, TX, US

1,666 tons

Vaulted injects organic waste into durable wells, where the carbon in the waste is sequestered as it decomposes. Using a specialized slurry injection technology, their process can handle a wide range of organic carbon sources with minimal energy and upfront processing. Their system has the potential to be deployed quickly at large scales.

Spiritus

Direct air capture

Los Alamos, NM

713 tons

Spiritus uses a sorbent made from commercially-available materials and a passive air contactor that requires little energy to capture CO₂. The CO₂-saturated sorbent is then regenerated using a novel desorption process, capturing the CO₂ and allowing the sorbent to be reused with less energy than a higher-heat vacuum chamber typically used in direct air capture approaches. The high-performance, inexpensive sorbent and lower regeneration energy provide a path to low cost.

Planetary

Ocean alkalinity enhancement

Nova Scotia, Canada

937 tons

Planetary harnesses the ocean for scalable removal. They introduce alkaline materials to existing ocean outfalls like wastewater plants and power station cooling loops. This speeds up the sequestration of CO₂ safely and permanently as bicarbonate ions in the ocean. Planetary then verifies the removal through advanced measurement and modeling techniques.

Mati

Enhanced weathering

US and India

1,513 tons

Mati applies silicate rock powders to agricultural fields, starting with rice paddy farms in India. These rocks react with water and CO₂ to produce dissolved inorganic carbon that is subsequently stored in the local watershed and eventually in the ocean. Mati relies on rice field flooding and higher subtropical temperatures to accelerate weathering, and extensive sampling and soil and river modeling to measure removal and deliver co-benefits to smallholder farmers.

Holocene

Direct air capture

Knoxville, TN, US

332 tons

Holocene captures CO₂ from air using organic molecules that can be produced at low cost. In the first step of their process, CO₂ is captured from air when it comes into contact with a liquid solution. In the second step, a chemical reaction crystallizes the material as a solid. That solid is heated up to release the CO₂, minimizing energy wasted in heating water. Holocene’s process runs at lower temperatures, further reducing the energy required, increasing energy flexibility, and lowering overall cost.

EDAC Labs

Enhanced weathering

Baltimore, MD, US

317 tons

EDAC Labs uses an electrochemical process to produce acid and base. The acid is used to start the recovery of valuable metals from mining waste, and the base is used to capture CO₂ from air. The acid and base streams are then combined to produce metals that can be sold for applications such as batteries, and solid carbonates, which permanently store CO₂.

CarbonRun

Ocean alkalinity enhancement

Nova Scotia, CA

1,291 tons

CarbonRun enhances the natural ability of river currents to weather abundant, low-cost limestone and reduce river acidity levels. This benefits river ecosystems locally and enhances the rivers’ ability to capture CO₂ from the atmosphere. Rivers, which are natural carbon transport systems, then deliver CO₂ to the ocean for permanent storage in the form of bicarbonate.

CarbonBlue

Direct ocean removal

Haifa, Israel

400 tons

CarbonBlue uses calcium in a closed-loop cycle to mineralize, separate, and remove dissolved CO₂ from water. This results in a pure stream of CO₂ that can be durably sequestered. Their approach can operate in freshwater or saltwater and can rely on waste heat for the regeneration process. The team plans to integrate with desalination plants and other water-withdrawing industries, reducing energy usage and costs.

Carbon Atlantis

Direct air capture

Munich, Germany

275 tons

Carbon Atlantis is using a process known as electrochemical pH-swing. Their system uses a solvent to capture CO₂ and an acid to release it. This approach is inspired by recent innovation in Proton Exchange Membrane fuel cells and electrolyzers, making the process both cost-effective and energy-efficient. The CO₂ is then run through

Banyu Carbon

Direct ocean removal

Seattle, WA, US

360 tons

Banyu Carbon uses sunlight to capture CO₂ from seawater. A reusable, light-activated molecule that becomes acidic when exposed to light causes carbon dissolved in seawater to degas as CO₂, which is then stored permanently. Because only a small portion of the visible light spectrum is needed to trigger the reaction, this is a highly energy-efficient approach to direct ocean removal.

Alkali Earth

Enhanced weathering

Northfield, MN, US

1,351 tons

Alkali Earth uses alkaline byproducts from industrial processes as carbon-removing gravel to apply to roads. These minerals act as a sink for atmospheric CO₂, storing it permanently while cementing road surfaces. The formation of CO₂-containing minerals within the gravel can be directly measured, leading to high-confidence in resulting removals.

Airhive

Direct air capture

London, UK

943 tons

Airhive is building a geochemical direct air capture system using a sorbent that can be made out of cheap and abundant minerals. This sorbent reacts rapidly with atmospheric CO₂ when mixed with air in Airhive’s fluidized bed reactor. Coupled with a regeneration process that’s powered by electricity to release the CO₂ for geologic storage, this provides a promising approach to low-cost DAC.