Sky-High Carbon Removal Showdown: Climeworks Gen 2 vs. Heirloom Limestone vs. Carbon Engineering’s AIR2 DAC
Climeworks’ Generation 2 DAC uses modular solid-sorbent containers; the Orca plant in Iceland has operated since 2021 at 4,000 t/yr, and Mammoth is designed for 36,000 t/yr (72 modules), though by May 2024 only 12 modules were online and capture was ~100 t. Gen3, unveiled in 2024, doubles CO₂ capture per module and cuts energy use by about 50%, with the first Gen3 deployment at the Project Cypress megaton-scale DAC hub in Louisiana planned for 2029 to reach 1,000,000 t/yr and a target cost of $250–$350/ton by 2030. Heirloom’s limestone DAC cycles CaCO₃ via calcination (~900°C) to CaO and back