Rubidium carbonate was used as an adsorbent to capture carbon dioxide from gaseous stream of carbon dioxide, nitrogen, and moisture in a fixed-bed to obtain the breakthrough data of CO2. Experiments were carried out at flow rates of carbon dioxide and nitrogen (5×10^(-6)-35×10^(-6) m3/min), moisture (0.5×10^(-6)-3.0×10^(-6) m3/h), amount of adsorbent (0.5×10^(-3)-1.8×10^(-3) kg), mole fraction of carbon dioxide (0.03-0.22), and different sorption temperatures (323-353 K) at atmospheric pressure. The deactivation model in the non-catalytic heterogeneous reaction systems was used to analyze the sorption kinetics among carbon dioxide, carbonate, and moisture, employing the experimental breakthrough data that fit the deactivation model better than the adsorption isotherm models in the literature.