The analysis of the data sets consisted of non-linear data fitting of the rate or equilibrium constants that define the
processes of Figure 1. In all calculations the pH was computed during the processes and all protonation equilibria
were continuously adjusted. The activities of all ionic species were estimated based on an expanded Debye-Hückel
equation. Note that the direct reaction of MEA with dissolved CO2 could not be observed in our data sets as the
concentration of CO2(aq) was too low under our conditions. The forward reaction rate has been determined by
several groups with values in the vincinity of 5000 M-1sec-1, see e.g.19. No information is given about the reverse
reaction.
Table 1 contains all relevant published rate and equilibrium constants, the table includes the reactions of CO2(aq) in
aqueous solution as well as the protonation constants of carbonate, bicarbonate, hydroxide and MEA. These values
were used in our data fitting.