permanent-carbon-storage
(5)
Carba
Carba is a Minneapolis-area climate-tech company that turns low-value waste biomass - dead trees, yard waste, and other biogenic scraps - into a stable, charcoal-like material called biocarbon (biochar). Using a patent-pending autothermal pyrolysis reactor and an anoxic (oxygen-starved) burial method, Carba locks carbon away for a certified 1,000+ years, most notably inside existing landfills where the material can also filter pollutants. The company sells the resulting permanent carbon-removal credits - including a five-year, 44,000-tonne deal with Microsoft - and aims to remove a billion tons of CO2 by 2035.
Capture6
Capture6 is a climate-tech company that turns the salty waste brine left over from desalination and water treatment into two things the world needs: fresh water and permanently removed atmospheric CO2. Its integrated platform converts brine into a CO2-absorbing solvent in a single step, eliminating costly brine disposal while producing freshwater, green chemicals, and durable carbon removal. Founded in 2021 and based in the San Francisco Bay Area with operations in New Zealand, the public benefit corporation works with water utilities, industry, and governments across California, Western Australia, New Zealand, and South Korea.
Vaulted Deep
Vaulted Deep is a Houston-based climate tech company that turns sludgy organic waste - biosolids, manure, food and agricultural waste, paper sludge - into permanent carbon removal by injecting it thousands of feet underground using patented slurry sequestration technology. Spun out of injection-well specialist Advantek in 2023, the company offers durable, low-cost, gigaton-scalable carbon dioxide removal while diverting hard-to-handle waste from landfills, oceans and fields. Its credits have been bought by Microsoft, Frontier Climate and others, and it won $8M in the Musk-backed XPRIZE Carbon Removal competition.
CREW Carbon
CREW Carbon is a Yale-spinout water and climate technology company based in Hamden, Connecticut. It retrofits municipal and industrial wastewater treatment plants with a closed-system enhanced-weathering process: dosing alkaline minerals into wastewater to convert dissolved CO2 into stable bicarbonate. The approach lowers operating costs and improves treatment performance for utilities while permanently and measurably removing atmospheric carbon, which it sells to corporate buyers as durable carbon removal credits.
Charm Industrial
Charm Industrial is a San Francisco-based climate company that converts agricultural residues into bio-oil through fast pyrolysis and injects it deep underground for permanent carbon removal. Founded in 2018 by Peter Reinhardt, Kevin Meissner, Shaun Meehan and Kelly Hering, Charm is one of the fastest-growing carbon dioxide removal companies and counts Frontier, Stripe, Microsoft, JPMorgan Chase, Meta and Shopify as customers.