Ex-Situ CO2 Mineralization: Bridging Laboratory Science and Industrial Reality. Part II: Techno-Economics, Life-Cycle Assessment, and Market-Driven Deployment Strategies

Abstract

Ex-situ CO₂ mineralization is moving from laboratory demonstration toward early commercial deployment, but gigaton-scale implementation requires credible economics, favorable life-cycle performance, real product markets, and standards-based verification. This second part of a two-part review examines the techno-economic, environmental, market, policy, and certification dimensions of the technology. Processing costs for industrial-residue systems are approximately \$30 to \$80 per ton of CO₂ on a cradle-to-gate basis for facilities colocated with the CO₂ source, excluding CO₂ capture and product credits, at a nominal 100 ktCO₂/year scale and \$0.08/kWh electricity; costs outside these boundary conditions differ substantially and are reported separately throughout. Revenue from carbonated aggregates, supplementary cementitious materials, precipitated calcium carbonate, and carbon-removal credits can offset a significant portion of these costs. Net carbon-removal efficiencies range from approximately 50% to 95% across pathways, a spread driven principally by feedstock activation demand and grid carbon intensity rather than by carbonation chemistry; residue-based systems integrating renewable energy typically achieve 75% to 95%, whereas activation-intensive natural silicate routes remain more energy sensitive. Commercial operators (CarbonFree, Fortera, Neustark, Greenore) stand at TRL 7–9 alongside earlier-stage ventures, with combined nameplate capacity of approximately 70–90 ktCO₂/year and independently verified delivered volumes that are substantially lower. Construction materials are the primary near-term market, with demand for low-carbon aggregates and cement additives growing rapidly. A bottom-up buildup of operational and publicly announced projects places 2030 capacity at approximately 0.4–5 MtCO₂/year. Reaching the 1–2 GtCO₂/year that IPCC-consistent carbon-removal portfolios would assign to mineralization by 2050 requires sustained capacity growth of 38–43% per year for two decades and a cumulative capital of approximately \$0.2–0.7 trillion for the mineralization system. Gigaton-scale deployment is therefore presented as a conditional scenario with explicitly stated preconditions, not as a forecast. Policy mechanisms, including enhanced 45Q credits, EU Innovation Fund support, and emerging carbon-removal procurement programs, are catalyzing investment.