To investigate the potential performance limits of direct air capture using amine-functionalised adsorbents, we minimised the specific work equivalent of a TVSA process using the global sensitivity analysis and a purity requirement of 98%. The results, including a comparison with pilot plant data, a modelling benchmark, and an optimistic industry future estimate, are shown in Table . Firstly, note that the electricity requirement from modelling studies appears to be much lower than industry data and future estimates. This implies that additional modelling of the whole system (i.e., the whole gas flow path), rather than just the adsorbent bed, may be required to capture the vacuum and blower work accurately. Secondly, if a "unicorn" adsorbent is found, our results suggest that the heat and electricity requirements can reduce by around 50% compared to current modelling benchmarks through adsorbent improvements alone. This agrees with optimistic energy consumption estimates by Climeworks, who also suggest a possible 50% reduction compared to current values. So, whilst the second law thermodynamic efficiencies of 45% found in this study will likely be unattainable, second law efficiencies of over 20%, as predicted by Climeworks, may be within reach if the right adsorbent is found. This contrasts with a previous commentary from Herzog, who argued that second law efficiencies of much above 10% for DAC are unrealistic. *** [107] However, we believe this may not be very optimistic.