A transformative low cost approach for Direct Air Mineralization of CO2 via repeated cycles of ambient weathering of metal oxides

Increasing concentration of CO 2 in the atmosphere poses a threat to the global climate. One
promising method for reducing atmospheric CO 2 is a repeated enhanced weathering process.
Enhanced weathering is a process where a natural reaction between CO 2 gas and minerals rich in
magnesium and/or calcium is accelerated to quickly form a solid carbonate. The cycle can be
repeated by separating the CO 2 from the carbonate by heating it up, extracting the pure CO 2 , and
exposing the reactive minerals to the air again. The technology we propose here combines
innovations in enhanced weathering alongside an engineered system that passively exposes these
reactive minerals to the air. It has the potential to significantly reduce the cost of permanent, high
quality carbon removal, and the resulting pure CO 2 can be permanently stored in geological
formations or sold for use in durable goods like cement or building materials. This project aims
to validate key parameters that have already been established at lab scale, build a
proof-of-concept of the engineered “passive air contactor”, and perform an economic and
geographic assessment of the process to find ideal locations to implement the process. In
addition to low costs, the process is limited in land requirements, can be located anywhere, is
highly verifiable and monitorable, is permanent, and limits the need for mining and extraction.
Bringing this technology and process to market has the potential to remove 1 gigaton of CO 2 by
2035, at a cost of $50/tCO 2 .