An evaluation of ex situ, industrial-scale, aqueous CO2 mineralization

It is essential to objectively evaluate the many CO2 mitigation strategies in order to prioritize investments of capital and research. Aqueous CO2 mineralization is one potential strategy to permanently sequester CO2, without the associated long-term monitoring and liability issues. Investigators are studying and optimizing aqueous CO2 mineralization for the production of inorganic carbonates and are scaling up some of these processes. This paper adopts a life-cycle approach toward the evaluation of energy requirements and discusses other potential barriers for three CO2 mineralization pathways: industrial caustics, naturally occurring minerals, and industrial wastes. This analysis is based on CO2 capture from a 1 GW coal-fired power plant using one of the three mineral mineralization pathways. The investigators utilize consistent system boundaries and process-modeling assumptions, standard engineering calculations to estimate energy requirements, and publicly available data for upstream energy requirements and for the production of products/co-products. The results suggest that some industrial wastes show promise for CO2 mineralization, but their availability is limited. The other pathways currently have large energy penalties and face other significant barriers, such as the production of large quantities of potentially hazardous waste and large-scale mining.

► Energy, mining and waste production are important considerations for ex situ CO2 mineralization.
► Some industrial wastes show promise for CO2 mineralization.
► CO2 mineralization with naturally occurring minerals is unlikely to be feasible in the near term.
► Ex situ mineralization processes requiring the production of caustics are unlikely to be feasible.