The benchtop flow-through reactor employed a standard quartz cuvette with a 1 cm pathlength. CO2 rich gas was flowed over a 0.5 cm 2 piece of contactor placed at the bottom of the cuvette. The gas at the outlet was analyzed using the in-line LI-COR Ò -850 infrared sensing system specifically tuned for low-concentration CO2 flow and for H2O sensing. The LI-COR Ò sensor was used to establish saturation of CO2 as well as H2O which reached 100% relative humidity within ~30 min.