https://doi.org/10.1016/j.ijggc.2018.10.008
“From these loaded solutions, microwave regenerations were performed at three different temperatures: 70, 80 and 90 °C and the CO2 desorption curves are reported in Fig. 4.”
Fig. 4. CO2 desorption rates obtained performing microwave regeneration at 70 °C (a); 80 °C (b); 90 °C (c).
”
These regenerations curves were obtained to analyse the efficiency of microwave to release CO2 at different temperatures and from various MEA concentrations. As the regeneration temperature increase, it is possible to see that the maximal CO2 desorption rate increase as it could be expected as more energy is supplied to the solution. It is also clearly noticeable that MEA concentrations of 30 wt%, but specially 40 wt% and 50 wt% have the best regeneration performances under all tested temperatures. The integration of these desorption curves can be done to calculate the absolute amount of stripped CO2 at each condition and for the sake of comparison, the released quantity of CO2 after 20 min are reported in Table 1. As for the desorption rates, the absolute stripped amounts of CO2 confirmed that MEA concentrations between 30 and 50 wt% perform better at all temperatures. Higher concentrations of 60 and 70 wt% released significantly less CO2 even though these solutions contained initially more CO2. As explained earlier, the high viscosity of these high MEA concentrations may explain their poorer regeneration performance. This viscosity effect seems to be validated as when temperature increased, a viscosity reduction is expected resulting in an increase of the % H.A. (as reported in Table 1) for the 60 and 70 wt% MEA concentrations.
Table 1. CO2 stripped amount after 20 min of microwave regeneration at different temperatures from data of Fig. 4.
| MEA | 70 °C | 80 °C | 90 °C | |||
|---|---|---|---|---|---|---|
| (wt%) | CO2 stripped (mol) | % H.A.a | CO2 stripped (mol) | % H.A. | CO2 stripped (mol) | % H.A. |
| 10 | 0.0017 | 53 | 0.0026 | 54 | 0.0029 | 44 |
| 30 | 0.0031 | 96 | 0.0044 | 90 | 0.0059 | 87 |
| 40 | 0.0032 | 100 | 0.0047 | 96 | 0.0066 | 98 |
| 50 | 0.0029 | 92 | 0.0049 | 100 | 0.0068 | 100 |
| 60 | 0.0017 | 52 | 0.0039 | 81 | 0.0057 | 85 |
| 70 | 0.0015 | 47 | 0.0027 | 55 | 0.0052 | 76 |
- a
-
%H.A.: Percentage of the Highest Amount of stripped CO2 at a given temperature among the different MEA concentrations.
“