Table 2.

Estimated capital expenditures (CAPEX) for the MgO looping process.

CAPEX	Cost [M$]		Comments
	Lower bound	Upper bound
Raw mineral	8,760	110,376	Lower bound: Estimated based on open pit mining cost ($10 tonne−1)75 and inflated to represent the required size reductions. Upper bound: cost of calcined magnesia76.
Air separation unit and condensera	785	2,260	Lower bound: scaled from Keith et al. installed calciner cost20. Upper bound: scaled from NASEM Report (built-in installation costs)7.
Oxy-fired calcinera	930	12,202	Lower bound: Scaled from Keith et al.20. Upper bound: Scaled from NASEM Report (Built-in 4.5× factor for new technology)7.
Land	129	1,796	Lower bound: Pasteur farm real estate at $1390 per acre. Upper bound: Farm real estate at $6430 per acre54.
Transportation (Conveyor System)a	129	1050	Price from mining cost data46,77. Lower bound: 1.5× factor to account for commercial possibility. Upper bound: 4.5× factor to account for new technology application.
Stirring equipment	28	84	Price quote for industrial farming equipment with a 1.5× factor for new equipment application.
Recollection equipment	22	67	Price quote for industrial farming equipment with a 1.5× factor for new equipment application.
Total CAPEX [M$]	$10,783	$127,835
CAPEX Annualized [M$ year−1]	$794	$16,053	CRF of 7.4% used for lower bound and 12.5% used for upper bound.
CO2 capture from air [GtCO2 year−1]	0.064	0.18	Only includes CO2 captured directly from the air.
Total CO2 capture [GtCO2 year−1]	0.12	0.34	Includes CO2 captured directly from the air and produced via calcination.
CAPEX [$ tCO2−1 captured]	$12	$89
CAPEX [$ tCO2−1 produced]	$7	$47

^aAssumed a scale-up factor⁶⁸.