Dive Brief:
- Microsoft has tapped climate tech startup Crew Carbon’s wastewater treatment technology to remove carbon dioxide emitted into the atmosphere by municipal wastewater plants.
- Crew’s wastewater alkalinity enhancement technology — developed at and backed by Yale University — will deliver Microsoft up to 23,602 verified carbon removal units, according to the offtake agreement announced earlier this month.
- This technology is designed to be integrated into existing wastewater infrastructure to make the treatment process more efficient and cost-effective while permanently removing the trapped carbon dioxide.
Dive Insight:
Crew’s technology accelerates the process of enhanced rock weathering — a carbon dioxide removal strategy that takes carbon out of the air and stores it in rocks — by dosing minerals like calcium carbonate or limestone in wastewater treatment reactors. This alters the pH levels and alkalinity of the wastewater to react with biogenic CO2 produced during sewage treatment, converting it into stable bicarbonate ions. This compound then locks the carbon into a permanent liquid form, preventing it from being released into the atmosphere, according to Crew.
“Microsoft’s offtake agreement with CREW supports the advancement of a novel, wastewater-based approach that is highly durable and measurable,” Phillip Goodman, Microsoft’s carbon removal portfolio director, said in an Aug. 4 press release. “CREW has shown that carbon removal in the wastewater sector is implementable and scalable with high Monitoring, Reporting and Verification (MRV) certainty.”
Crew’s deal with Microsoft follows other carbon removal agreements the startup has signed with corporate buyers like JPMorgan Chase, Google, Stripe, Autodesk and more through the decarbonization initiative Frontier, backed in part by the aforementioned companies. Crew said in the release it has over $40 million in carbon removal commitments.
The offtake agreement comes after an April report alleged Microsoft — which is responsible for the bulk of contracted durable carbon removals to date — had paused future CDR purchases. At the time, Microsoft’s chief sustainability officer told ESG Dive that its “carbon removal program has not ended.”
Microsoft was the top carbon removal purchaser in the first quarter of this year, accounting for 43% of Q1’s purchases.
