https://doi.org/10.1016/j.ijggc.2018.10.008
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Desorption curves of Fig. 4 were all obtained using an initial microwave power of 100 W to quickly heat the solution to the desired regeneration temperature and then the power was manually reduced and controlled to maintain that temperature constant. Values of these constant-temperature powers were recorded and reported in Fig. 5 as some interesting trends can be observed. First, it can be seen that performing the regeneration at higher temperatures required, as expected, higher microwave powers to account for example for higher heat losses from the system, for higher vapour emissions but also for desorbing higher amount of CO2.
Fig. 5. Constant-temperature microwave powers for various MEA concentrations and temperatures. Dotted lines are included to show trends.
Besides, the analysis of the MEA concentration effect on the power consumption seems to emphasis once again the influence of viscosity on the microwave desorption process. For each tested temperature, the power consumptions were quite similar at low MEA concentrations, as indicated by the horizontal dotted lines in Fig. 5, until a given concentration was reached where the power consumption started to decrease with further concentration (or viscosity) increase. These threshold concentrations were found to increase with temperature (around 35 wt% at 70 °C, 40 wt% at 80 °C, and 50 wt% at 90 °C) but more interestingly, they are all linked by the same viscosity value (calculated from literature data (Amundsen et al., 2009)). This indicate that above that viscosity value, the desorption of CO2 may be hindered by mass transfer limitations resulting in lower desorbed amount and therefore a lower microwave power consumption is necessary.
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