Prospective life cycle assessment of megatonne-scale direct air carbon capture and storage via calcium-looping - Preprint

[Geoengineering News]

https://chemrxiv.org/engage/chemrxiv/article-details/690cdd17a482cba1228796d2

Authors: Vittoria Bolongaro, David Yang Shu, Noah McQueen, André Bardow 

12 November 2025

Abstract 

Calcium-looping direct air capture is a mature technology that could contribute to the gigatonne-scale carbon removal industry. However, the environmental impacts and tradeoffs of its large-scale deployment have not been assessed. Here, we perform a prospective life cycle assessment of megatonne-scale calcium-looping DACCS systems, demonstrating removal efficiencies exceeding 80% for autonomous systems by 2030, and ranging from 85% to 96% by 2050, depending on the energy system. Net removal of 1 GtCO2 increases other environmental impacts by under 2% of the global safe operating space in most scenarios. Calcium-looping removal efficiency aligns with other mature DACCS technologies, indicating location and supply chain integration as key selection criteria. We thus investigate integrating calcium-looping DACCS with cement plants, offering dual benefits for carbon removal and cement decarbonization. Our results indicate that by 2050, DACCS-cement integration could produce net-negative cement if limestone is cycled once through the DAC units before entering the cement kiln. These findings position calcium-looping DACCS as a promising solution for both CO2 removal and cement decarbonization.

Source: ChemRxiv