Our portfolio

We work with a multidisciplinary group of top scientific experts to help us evaluate promising carbon removal technologies. You can explore our growing portfolio of projects below or read about our selection process here.

Purchase date
Pathway
Location
Track
Supplier
Delivery status
32 total projects
Splash image for Vaulted Deep

Vaulted Deep

Vaulted injects carbon-rich organic waste biomass deep underground for permanent storage. This disposal method also replaces harmful disposal practices like land application and incineration. As a spinoff from an established waste disposal company, Vaulted benefits from already-permitted well infrastructure, and a team with longstanding operational experience.

Track
Offtake - 2024
Prepurchase - 2023
Contracted tons
154,146
Location
Houston, TX, US
Delivered tons
1,666
Pathway
Biomass carbon removal & storage
Splash image for Lithos

Lithos

Lithos accelerates the natural ability of rocks to absorb CO₂ by spreading superfine crushed basalt on farmlands and measuring the removal empirically. They’re pioneering a novel measurement technique that more accurately quantifies the carbon permanently removed from enhanced weathering.

Track
Offtake - 2023
Prepurchase - 2022
Contracted tons
154,880
Location
San Francisco, CA, US
Pathway
Enhanced weathering
Splash image for CarbonCapture Inc.

CarbonCapture Inc.

CarbonCapture’s direct air capture machines use solid sorbents that soak up atmospheric CO₂ and release concentrated CO₂ when heated. CarbonCapture’s core innovation is making the capture system modular and upgradeable so that they can swap in best-in-class sorbents as they become available. The captured CO₂ stream is then stored permanently underground.

Track
Offtake - 2023
Contracted tons
45,500
Location
Los Angeles, CA, US
Pathway
Direct air capture
Splash image for Heirloom

Heirloom

Over geologic timescales, CO₂ chemically binds to minerals and permanently turns to stone. Heirloom is building a direct air capture solution that accelerates this process to absorb CO₂ from the ambient air in days rather than years, and then extracts the CO₂ to be stored permanently underground.

Track
Offtake - 2023
Contracted tons
26,889
Location
Brisbane, CA, US
Pathway
Direct air capture
Splash image for Airhive

Airhive

Airhive is building a geochemical direct air capture system using an ultra porous sorbent structure 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.

Track
Prepurchase - 2023
Contracted tons
943
Location
London, UK
Pathway
Direct air capture
Splash image for Alkali Earth

Alkali Earth

Alkali Earth uses alkaline byproducts, like steel slag, as gravel aggregates for building road surfaces. The calcium- and magnesium-rich minerals in the gravel react with atmospheric CO₂ to form stable carbonates, storing it permanently while cementing the road surfaces. Spreading the gravel across roads increases the surface area exposed to CO₂ and leverages road traffic to agitate the gravel further, accelerating CO₂ uptake.

Track
Prepurchase - 2023
Contracted tons
1,351
Location
Northfield, MN, US
Pathway
Enhanced weathering
Splash image for Banyu Carbon

Banyu Carbon

Banyu uses sunlight to capture CO₂ from seawater and store it permanently. A reusable, light-activated molecule that becomes acidic when exposed to light causes carbon dissolved in seawater to degas as CO₂, which is then compressed for storage. Because only a small portion of the visible light spectrum is needed to trigger the reaction and the light-activated molecule can be reused thousands of times, this is a highly energy-efficient approach to direct ocean removal.

Track
Prepurchase - 2023
Contracted tons
360
Location
Seattle, WA, US
Pathway
Direct ocean removal
Splash image for Carbon Atlantis

Carbon Atlantis

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. Their cell architecture is designed to allow for industrial-sized stacks, and the components of this modular system are readily available and industry-proven, making the process cost-effective and energy-efficient. The CO₂ is then run through Paebbl's mineralization process for permanent storage in construction materials.

Track
Prepurchase - 2023
Contracted tons
275
Location
Munich, Germany
Pathway
Direct air capture
Splash image for CarbonBlue

CarbonBlue

CarbonBlue has developed a calcium looping process to remove CO₂ from seawater or freshwater. Their novel mineralization, dissolution and brine hydrolysis regeneration releases CO₂ captured from water without needing any external feedstock of minerals or chemicals. The reactors are highly energy efficient and require a low enough regeneration temperature to enable utilization of waste heat.

Track
Prepurchase - 2023
Contracted tons
400
Location
Haifa, Israel
Pathway
Direct ocean removal
Splash image for CarbonRun

CarbonRun

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. The alkalinity can be monitored at multiple points throughout the river, simplifying measurement.

Track
Prepurchase - 2023
Contracted tons
1,291
Location
Halifax, Nova Scotia, CA
Pathway
Ocean alkalinity enhancement
Splash image for EDAC Labs

EDAC Labs

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. The EDAC Labs process is energy efficient, uses abundant mine wastes, and produces valuable revenue-generating co-products.

Track
Prepurchase - 2023
Contracted tons
317
Location
Baltimore, MD, US
Pathway
Enhanced weathering
Splash image for Holocene

Holocene

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. Their process runs at lower temperatures, further reducing the energy required and increasing energy flexibility.

Track
Prepurchase - 2023
Contracted tons
332
Location
Knoxville, TN, US
Pathway
Direct air capture
Splash image for Mati

Mati

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.

Track
Prepurchase - 2023
Contracted tons
1,513
Location
Houston, TX, US
Delivered tons
50
Pathway
Enhanced weathering
Splash image for Planetary

Planetary

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.

Track
Prepurchase - 2023
Contracted tons
937
Location
Dartmouth, Nova Scotia, CA
Pathway
Ocean alkalinity enhancement
Splash image for Spiritus

Spiritus

Spiritus uses a sorbent made from a readily available polymer with a high capacity for CO₂. The CO₂-saturated sorbent is 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.

Track
Prepurchase - 2023
Contracted tons
713
Location
Los Alamos, NM, US
Pathway
Direct air capture
Splash image for Carboniferous

Carboniferous

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 preserved and stored durably in ocean sediments. The team will experiment to determine the stability of sunken biomass as well as the interaction with ocean biogeochemistry.

Track
R&D - 2023
Contracted tons
-
Location
Houston, TX, US
Pathway
Biomass carbon removal & storage
Splash image for Rewind.earth

Rewind.earth

Rewind sinks 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. Through pilot deployments, the team will examine the durability of sunken biomass and better ways to measure and model the carbon removed.

Track
R&D - 2023
Contracted tons
-
Location
Tel Aviv, Israel
Pathway
Biomass carbon removal & storage
Splash image for Charm Industrial

Charm Industrial

Charm Industrial has created a novel process for preparing and injecting bio-oil into geologic storage. Bio-oil is produced from biomass and maintains much of the carbon that was captured naturally by the plants. By injecting it into secure geologic storage, they’re making the carbon storage permanent.

Track
Offtake - 2023
Contracted tons
112,003
Location
San Francisco, CA, US
Delivered tons
483
Pathway
Biomass carbon removal & storage
Splash image for Arbor

Arbor

Arbor is developing a modular, compact approach to Biomass Carbon Removal and Storage (BiCRS), the process of removing carbon by converting biomass waste to products such as electricity and permanently storing the CO₂ underground. Their technology combines a gasifier that can work flexibly across biomass types with an advanced turbine that maximizes electrical efficiency. Arbor’s modular system can be quickly deployed and is designed to be manufactured at substantially lower costs.

Track
Prepurchase - 2022
Contracted tons
1,000
Location
Los Angeles, CA, US
Pathway
Biomass carbon removal & storage
Splash image for Arca

Arca

Arca is capturing CO₂ from the atmosphere and mineralizing it into rock. They work with producers of critical metals, transforming mine waste into a massive carbon sink. With autonomous rovers, their approach accelerates carbon mineralization, a natural process storing CO₂ permanently as new carbonate minerals. By creating a system that works directly at the mine site, Arca avoids the cost and emissions of moving material to processing facilities.

Track
Prepurchase - 2022
Contracted tons
380
Location
Vancouver, British Columbia, CA
Pathway
Enhanced weathering
Splash image for Captura

Captura

Captura is harnessing the ocean for scalable removal by designing an electrochemical process to separate acid and base from seawater. The acid is used to remove CO₂ that’s present in seawater, which is injected for permanent geologic storage. The base is used to treat and return the remaining water safely to the ocean, and the ocean then draws down further CO₂ from the atmosphere. Captura is developing optimized membranes to increase electrical efficiency and reduce removal costs.

Track
Prepurchase - 2022
Contracted tons
508
Location
Pasadena, CA, US
Pathway
Direct ocean removal
Splash image for Carbon To Stone

Carbon To Stone

Carbon To Stone is developing a new form of direct air capture, in which a solvent that binds CO₂ is regenerated by reacting with alkaline waste materials. By replacing conventional solvent regeneration using heat or pressure changes with direct mineralization of low-cost alkaline wastes such as steel slag, the team can significantly reduce the energy, and thus the cost, required. The CO₂ is durably stored as solid carbonate materials that can be used for alternative cements.

Track
Prepurchase - 2022
Contracted tons
1,269
Location
Ithaca, NY, US
Pathway
Direct air capture
Splash image for Cella

Cella

Cella increases the options for safe and secure carbon storage via mineralization. They accelerate the natural process that converts CO₂ into solid mineral form by injecting it into volcanic rock formations together with saline water and geothermal brine waste, with an approach that lowers cost and minimizes environmental impacts. Cella’s technology integrates low-carbon geothermal heat and can be paired with a variety of capture methods.

Track
Prepurchase - 2022
Contracted tons
2,198
Location
New York, NY, US
Pathway
Storage only
Storage subcategory
Geologic mineralization
Splash image for CREW

CREW

CREW is building specialized reactors to enhance natural weathering. The container-based system creates optimized conditions to speed up the weathering of alkaline minerals, and the discharged water stores CO₂ from wastewater safely and permanently as bicarbonate ions in the ocean. CREW’s system makes measuring CO₂ removed easier and can react with CO₂ from a variety of sources, including direct air capture and biomass systems, to maximize scale.

Track
Prepurchase - 2022
Contracted tons
615
Location
New Haven, CT, US
Pathway
Enhanced weathering
Splash image for Inplanet

Inplanet

Inplanet accelerates natural mineral weathering to permanently sequester CO₂ and regenerate tropical soils. They partner with farmers to apply safe silicate rock powders under warmer and wetter conditions that can result in faster weathering rates and thus faster CO₂ drawdown. The team is developing monitoring stations to generate public field trial data to improve the field’s understanding of how weathering rates vary under tropical soil and weather conditions across Brazil.

Track
Prepurchase - 2022
Contracted tons
1,041
Location
Munich, Germany
Pathway
Enhanced weathering
Splash image for Kodama

Kodama

Kodama Systems and the Yale Carbon Containment Lab are deploying a proof-of-concept method of storing waste woody biomass by burying it in anoxic chambers underground, preventing decomposition. The team will experiment with how chamber conditions and above-ground disturbances impact durability and reversal risk.

Track
R&D - 2022
Contracted tons
-
Location
Sonora, CA, US
Pathway
Biomass carbon removal & storage
Splash image for Nitricity

Nitricity

Nitricity is exploring the potential of integrating carbon removal into a novel process for the electrified production of clean fertilizer. This process combines carbon-neutral nitrogen compounds, phosphate rock and CO₂, producing nitrophosphates for the fertilizer industry and storing CO₂ durably as limestone. This new pathway could present a low-cost storage solution for dilute CO₂ streams with co-benefits of decarbonizing the fertilizer industry.

Track
R&D - 2022
Contracted tons
-
Location
Fremont, CA, US
Pathway
Storage only
Storage subcategory
Surface mineralization
Splash image for AspiraDAC

AspiraDAC

AspiraDAC is building a modular, solar-powered direct air capture system with the energy supply integrated into the modules. Their metal-organic framework sorbent has low temperature heat requirements and a path to cheap material costs, and their modular approach allows them to experiment with a more distributed scale-up.

Track
Prepurchase - 2022
Contracted tons
500
Location
Sydney, Australia
Pathway
Direct air capture
Splash image for Calcite-Origen

Calcite-Origen

This project, a collaboration between 8 Rivers and Origen, accelerates the natural process of carbon mineralization by contacting highly reactive slaked lime with ambient air to capture CO₂. The resulting carbonate minerals are calcined to create a concentrated CO₂ stream for geologic storage, and then looped continuously. The inexpensive materials and fast cycle time make this a promising approach to affordable capture at scale.

Track
Prepurchase - 2022
Contracted tons
278
Location
Durham, US and Bristol, UK
Pathway
Direct air capture
Splash image for RepAir

RepAir

RepAir uses clean electricity to capture CO₂ from the air using a novel electrochemical cell and partners with Carbfix to inject and mineralize the CO₂ underground. The demonstrated energy efficiency of RepAir’s capture step is already notable and continues to advance. This approach has the potential to deliver low-cost carbon removal that minimizes added strain to the electric grid.

Track
Prepurchase - 2022
Contracted tons
199
Location
Tel Aviv, Israel
Pathway
Direct air capture
Splash image for Travertine

Travertine

Travertine is re-engineering chemical production for carbon removal. Using electrochemistry, Travertine produces sulfuric acid to accelerate the weathering of ultramafic mine tailings, releasing reactive elements that convert carbon dioxide from the air into carbonate minerals that are stable on geologic timescales. Their process turns mining waste into a source of carbon removal as well as raw materials for other clean transition technologies such as batteries.

Track
Prepurchase - 2022
Contracted tons
365
Location
Boulder, CO, US
Pathway
Enhanced weathering
Splash image for Living Carbon

Living Carbon

Living Carbon wants to engineer algae to rapidly produce sporopollenin, a highly durable biopolymer which can then be dried, harvested and stored. Initial research aims to better understand the field’s thinking on the durability of sporopollenin as well as the optimal algae strain to quickly produce it. Applying synthetic biology tools to engineer natural systems for improved and durable carbon capture has the potential to be a low-cost and scalable removal pathway.

Track
R&D - 2022
Contracted tons
-
Location
Hayward, CA, US
Pathway
Biomass carbon removal & storage

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