Table 2 Comparison of this work and emerging technologies for DAC, DOC, and point source capture. CO₂ separation work with “th” subscript denotes thermal energy inputs, whereas “e” subscript denotes electrical work input.

From: Low energy carbon capture via electrochemically induced pH swing with electrochemical rebalancing

Method	Purpose	CO₂ separation work inputs (kJ mol_CO2⁻¹)	Current density (mA cm⁻²)
Alkaline solvent^2,9	DAC	264–396_th^a	N/A
Solid amine sorbents²	DAC	150–211_th^b	N/A
Amino acid solvents and solid bis-iminoguanidines¹⁰	DAC	152–422_th^c	N/A
Fuel cell concentrator¹⁷	DAC	350_e^d	0.5
Electrochemical alkaline sorbent regeneration³¹	DAC	374_e^f	0.5
Processing seawater within a BPMED reactor¹³	DOC	155_e^g	3.3
Titrating seawater with BPMED acid/base¹²	DOC	394_e^h	100
Traditional amine ab-/desorption⁴	Point source capture	132–150_th	N/A
Amine ad-/desorption with advanced flash stripper³²	Point source capture	92_thⁱ	N/A
Shell Cansolv⁶	Point source capture	103_th	N/A
Petra Nova³³	Point source capture	89_th^j	N/A
Quinone Direct binding⁷	Point source capture	56_e^k	0.5
EMAR⁸	Point source capture	30–113_e^l	2.7–11.8
This work	0.1 bar capture	61–145_e	20–150
	0.4 mbar capture	121–237_e	20 (extrapolated)

^aWork input excludes electrical work required to operate air–liquid contactor, pellet reactor, and auxiliary equipment.
^bDesorption energy for mid-range scenario; work input excludes electrical work required to operate air contactor fans and desorption vacuum pump.
^cEnergy required for bis(iminoguanidine) regeneration.
^dHydrogen gas is the energy source; Energy required to operate water cooling system is excluded.
^fThe process starts with a bicarbonate/carbonate solution, mimicking a solution saturated with DIC under 0.4 mbar inlet pCO₂. The value is the required work for alkaline sorbent solution regeneration.
^gWork input excludes costs for ocean water intake, pre-treatment, and pumping.
^hEnergy consumption for the best-case acid process; work input excludes electrical work required to operate pumps and chiller.
ⁱThe inlet gas source contains 11.3% CO₂, and the exit is 99% CO₂.
^jThe inlet gas source contains 11% CO₂, and the exit is 97% CO₂. This energy is calculated using the electrical power cost, excluding 50% used for compression, plus the steam cost associated with the CCS plant. The captured CO₂ was offset by the CO₂ emission in the CCS plant.
^kThe inlet gas source was simulated flue gas with 15% CO₂ and 3% O₂ in N₂, and exit partial pressure was ~0 bar. Note that the energy cost was calculated based on the amount of CO₂ absorbed, yet it is not clear that all absorbed CO₂ was released.
^lEnergy and current density values adopted from Fig. 8a of ref. ⁸. Simulated flue gas is 15% CO₂ in N₂.

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Table 2 Comparison of this work and emerging technologies for DAC, DOC, and point source capture. CO₂ separation work with “th” subscript denotes thermal energy inputs, whereas “e” subscript denotes electrical work input.

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