(381s) An Experimental Investigation: Continuous Fixed Bed Adsorption of CO2 over Carbon Based Adsorbent

Increased carbon dioxide concentration in the environment is leading to serious issues for humankind, including increased earth’s surface temperature, climate change, ocean acidification, and impact on ecosystem. The utmost domineering issue is the alarming pace at which the CO₂ level is accelerating within the environment. The current work demonstrates the comprehensive experimental study on continuous fixed bed CO₂ adsorption over commercial activated carbon RBAA-3. The carbon-based adsorbent (RBAA-3) is characterized in detail by BET surface area analyzer, SEM, and Raman analyses. In experimental study, the breakthrough response is analyzed as a function of temperature, feed gas flow rate, and initial CO₂ concentrations. The lower temperature (or 298K) remained best for CO₂ capture over RBAA-3 and allowed robust adsorption up to 1140 seconds compared to the higher temperatures (328K; 878 sec). The breakthrough time of CO₂ adsorption decreased with increasing feed gas flow rate because of lower residence time at higher flow rates. Interestingly, the lower initial CO₂ concentration showed the better breakthrough profile compared to the higher one. The adsorbent effectiveness is predicted as CO₂ adsorption capacity (mmol/g) determined under varied set of operating conditions. Further, the bed characteristics parameters such as capacity utilization factor, column efficiency, length of mass transfer zone, and usable bed height are also evaluated to determine the adsorption system performance for CO₂ capture. The maximal CO₂ capacity of 1.18 mmol/g was achieved at 298 K with flow feed rate of 5 L/min with C_in=5%. The minimal L_MTZ nearly equal to 1.77 cm was determined with a good utilization factor of 0.965 at 298 K. The maximum usable bed height is 23.39 cm, with an improved efficiency of 93.57%. The superior adsorption characteristics and capture capacity exhibited by RBAA-3 suggested that utilized adsorbent could be economically used for CO₂ capture.