Advancing sustainable CO2 mitigation: Experimental and computational analysis of thermal carbon chitosan sorbent for automotive exhaust capture

Abstract

• The study focuses on the use of thermal carbonized chitosan (TCCS) as an adsorbent for capturing CO 2 from vehicle exhaust emissions. • The adsorption process was confirmed to be exothermic (ΔH = −26.42 kJ.mol −1 ) and primarily physical, with a low activation energy of 4.27 kJ.mol −1 . • Key performance indicators included a breakthrough time of 1280 s and saturation time of 2300 s, with 70 % of the adsorption bed utilized during the process. • A CFD simulation was conducted to validate experimental results, showing strong correlation and reliability of the TCCS-based adsorption system. • The research highlights TCCS’s potential as a sustainable solution for mitigating CO 2 emissions from automotive sources. This study investigated the efficiency of thermal carbon chitosan (TCCS) sorbent for CO 2 capture from vehicle exhaust emissions within a designed adsorption system. TCCS was synthesized and meticulously characterized using a series of analytical techniques, including Brunauer-Emmett-Teller (BET) surface area analysis, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Energy Dispersive X-ray Spectroscopy (EDX), and Differential Scanning Calorimetry (DSC). The TCCS adsorbent showed high thermal stability and a heating value (HHV) of 23.5 MJ/kg. Adsorption isotherm study demonstrated that the maximum capacity of CO 2 adsorption is 0.084 kg.CO 2 /kg.TCCS, as well as confirmation of the exothermic nature of the process with an enthalpy change (ΔH) of −26.42 kJ/mol. Kinetics study indicated that the adsorption mechanism was physical in nature, characterized by an activation energy (E D ) of 4.27 kJ/mol, which is lower than the threshold of 8 kJ/mol. The experimental breakthrough curve revealed a breakpoint time (t b ) of 1280 s, a saturation time (t s ) of 2300 s and illustrated that about 70 % of the adsorption bed (H b ) was used during the CO 2 adsorption process. To further validate the experimental results, a Computational Fluid Dynamics (CFD) simulation was conducted, revealing a strong correlation with the experimental data. The low error values between the experimental and CFD predicted results underscore the reliability of the TCCS-based adsorption system for effective CO 2 capture. This research contributes valuable insight into the potential of TCCS as a sustainable adsorbent for mitigating CO 2 emissions from automotive sources.