Adsorption isotherm and kinetic characteristics of sawdust, shrimp shell, and wild sugarcane-based activated carbon for CO2 capture

Anthropogenic activities and transportation are primarily responsible for the release of CO2 into the atmosphere. In this work, waste-based adsorbents are used to capture CO2 by sorption. Activated carbon was prepared using wild sugarcane and shrimp shells, and it was analyzed using X-ray diffraction, field emission scanning electron microscope, Fourier transform infrared spectroscopies, and X-ray dispersive spectroscopy. Sorption results show a maximum CO2 uptake of 5.034 x 10(-3) mol/g and 4.014 x 10(-3) mol/g for the sorbent activated carbon-wild sugar cane shrimp shells (AC-WSSS) and activated carbon-sawdust shrimp shells (AC-SDSS), respectively. Thermodynamic studies of the sorbent AC-WSSS and AC-SDSS were performed and Delta G degrees (7.45 and 7.48 kJ/mol), Delta H degrees (13.66 and -48.57 kJ/mol), and Delta S degrees (38.32 and 36.44 kJ/mol.K) were calculated, and the feasibility of the process was evaluated. The experimental data of the activated carbon isotherm from sawdust and wild sugar cane shells was demonstrated with Langmuir, Freundlich, D-R, Temkin and Sips adsorption isotherm. Higher R-2 (0.9855) value for Langmuir isotherm shows the applicability of the model. The equilibrium point was reached in 80 and 85 min for the prepared biomass AC-WSSS and AC-SDSS, respectively. Desorption results show that the sorbent can be recycled for 3 cycles. It is observed that more than 80% of CO2 is removed from acetone even after three cycles of desorption experiments. From this work, it reveals that the adsorbent AC-WSSS and AC-SDSS finds to be a better potential for CO2 capture as adsorbent.