Stripe Climate

44.01 turns CO₂ into rock, harnessing the natural power of mineralization. Their technology injects CO₂ into peridotite, an abundantly available rock, where it is stored permanently. This storage approach can be paired with a variety of capture technologies.

Eion accelerates mineral weathering by mixing silicate rocks into soil. Their pelletized product is applied by farmers and ranchers to increase carbon in the soil, which over time makes its way into the ocean where it’s permanently stored as bicarbonate. Alongside their technology development, Eion is also conducting a novel soil study to improve the field’s measurement of CO₂ uptake.

Seachange leverages the power and scale of the world’s oceans to remove carbon. Their experimental electrochemical process sequesters CO₂ in seawater as carbonates, an inert material comparable to seashells, thereby enabling energy-efficient and permanent CO₂ removal.

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

CarbonBuilt’s process readily converts dilute CO₂ into calcium carbonate, creating a “no compromise” low-carbon alternative to traditional concrete. As a profitable and scalable solution for permanent CO₂ storage, CarbonBuilt’s technology platform can serve as a critical component of future carbon removal systems using direct air capture.

Climeworks uses renewable geothermal energy and waste heat to capture CO₂ directly from the air, concentrate it, and permanently sequester it underground in basaltic rock formations with Carbfix. While it’s early in scaling, it’s permanent, easy to measure, and the capacity of this approach is theoretically nearly limitless.

Project Vesta captures CO₂ by using an abundant, naturally occurring mineral called olivine. Ocean waves grind down the olivine, increasing its surface area. As the olivine breaks down, it captures atmospheric CO₂ from within the ocean and stabilizes it as limestone on the seafloor.

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.

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.

This project, a collaboration between 8 Rivers’ Calcite 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.

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.

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.

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.

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.

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.