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 \({\hbox {CO}}_{2}\) 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 \({\hbox {CO}}_{2}\) production and energy consumption. The parametric study on the desorption time shows that there is a desorption time yielding the highest \({\hbox {CO}}_{2}\) production at low energy consumptions. Low evacuation pressures are necessary to reach high \({\hbox {CO}}_{2}\) 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 \({\hbox {CO}}_{2}\) desorption kinetics and allows reaching higher \({\hbox {CO}}_{2}\) 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.

在这项工作中，通过设计和分析两个温度-真空摆动吸附（TVSA）循环，研究了通过吸附的直接空气捕获（DAC）。在第一部分中，提出了一种新颖的描述\（{\ hbox {CO}} _ {2} \）在水蒸气存在下的吸附的方法，用于从文献中收集的共吸附动力学和热力学数据。其次，提出了两种TVSA循环设计：一种通过外部加热进行解吸，另一种采用蒸汽吹扫。提出了一种确定循环步骤时间的示意方法，并使用详细的第一原理模型通过循环模拟对运行条件进行了参数研究。最后，根据\（{\ hbox {CO}} _ {2} \）比较两个周期生产和能源消耗。对解吸时间的参数研究表明，在低能耗下，有一个解吸时间产生最高的\ {{hbox {CO}} _ {2} \）产量。低排气压力是要达到高\（{\ hbox中{CO}} _ {2} \）的生产，但较高的压力抽空到显示总是有利在特定的电能量需求方面。蒸汽吹扫需要额外的热能成本，但不仅可以降低单位电能消耗，还可以提高\（{\ hbox {CO}} _ {2} \）的解吸动力学，并可以达到更高的\（{\ hbox {CO}} _ {2} \）在较低的疏散压力下生产。这项工作的结果提出了将功率和热量的可用性直接与循环设计联系起来的可能性。