Product · Materials Science
Product · InnDex 42 · Evidence provided · High specification risk
DAC-integrated manufactured limestone aggregate that chemically fixes atmospheric CO₂ into construction material.
Mission Zero's direct air capture unit (250 t CO₂/yr) feeds captured CO₂ into OCO Technology's accelerated carbonation process, which mineralizes it into limestone aggregate for concrete and fill applications. Addresses construction's reliance on virgin limestone and industrial CO₂ sources by closing the carbon loop at source. Operational since May 2025 in Norfolk, UK.
Mission Zero's direct air capture unit at Norfolk feeds captured CO₂ into OCO Technology's accelerated carbonation process, mineralising it into limestone aggregate for concrete and fill applications — a closed loop where atmospheric carbon becomes a structural material rather than a managed waste stream. Operational since May 2025 and government-backed, this is one of very few DAC-to-construction-material pathways with a functioning physical facility rather than a lab or modelled proposition. One piece of provided evidence backs the record. The carbon arithmetic is where scrutiny is warranted: DAC electricity demand is roughly 4–6 MWh per tonne of CO₂ captured, and the net sequestration claim depends entirely on the grid carbon intensity of that power draw — a renewable-powered facility and a grid-average facility produce very different lifecycle numbers. The facility capacity of 250 tonnes CO₂ per year is a pilot scale; at that output, aggregate supply into construction is a demonstration quantity, not a supply-chain option for a major project. Compressive strength and durability performance of DAC-carbonated aggregate versus virgin limestone requires extended field validation that the April 2025 operational start cannot yet provide. Market adoption economics hinge on carbon pricing, embodied-carbon accounting standards, and regulatory incentives that are not uniformly in place. The right interest level for a specifier is serious and anticipatory — this technology has the right bones — but the supply chain, verified carbon accounting, and cost basis needed for specification are a few years away from maturity.
Deployment is real and government-backed (DESNZ DAC Innovation Programme), with operational start confirmed May 2025 and C2I award documented. However, the core claim—that the final aggregate is carbon-negative—rests on unvalidated assumptions. No third-party LCA, EPD, or verified carbon accounting has been published. Material performance in concrete (durability, strength, workability) is not disclosed. DAC capture efficiency (~250 t/yr) and ACT process yields are not independently audited. The source excerpt is primarily website boilerplate with no technical detail. Risk of greenwashing lies in claiming carbon-negative status without cradle-to-gate or cradle-to-grave verification that accounts for DAC energy input (grid electricity source unknown), ACT process energy, transport, and aggregate application.
#direct_air_capture #carbon_fixation #manufactured_aggregate #decarbonisation #accelerated_carbonation