Abstract
In this work, direct air capture (DAC) via adsorption is studied through the design and analysis of two temperature–vacuum swing adsorption (TVSA) cycles. In the first part, a novel way of describing the adsorption of $${\hbox {CO}}_{2}$$
CO
2
in presence of water vapor is proposed for co-adsorption kinetic and thermodynamic data gathered from the literature. Secondly, two TVSA cycle designs are proposed: one with a desorption step via external heating, and one with a steam purge. A schematic method for the determination of the cycle step times is proposed and a parametric study on the operating conditions is performed via cycle simulations using a detailed, first principles model. Finally, the two cycles are compared in terms of $${\hbox {CO}}_{2}$$
CO
2
production and energy consumption. The parametric study on the desorption time shows that there is a desorption time yielding the highest $${\hbox {CO}}_{2}$$
CO
2
production at low energy consumptions. Low evacuation pressures are necessary to reach high $${\hbox {CO}}_{2}$$
CO
2
production, but higher evacuation pressures show to be always favorable in terms of specific electrical energy requirements. A steam purge requires an additional thermal energy cost, but it not only allows decreasing the specific electrical energy consumptions, it also enhances $${\hbox {CO}}_{2}$$
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2
desorption kinetics and allows reaching higher $${\hbox {CO}}_{2}$$
CO
2
productions at milder evacuation pressures. The results of this work present the possibility to directly relate the availability of power and heat to the design of the cycle.
Correction to: Analysis of direct capture of CO2 from ambient air via steam-assisted temperature–vacuum swing adsorption
