Investigation of the performance of activated carbon derived from ripe plantain peels for CO2 capture: Modelling and optimisation using response surface methodology

This study investigates the potential of activated carbon derived from ripe plantain peels (PPAC) for carbon dioxide (CO2) capture. PPAC was prepared through carbonization and activation using H3PO4, and its unique properties were extensively characterized which revealed irregular sponge-like protrusions and well-defined pores under Scanning Electron Microscopy (SEM). Elemental analysis identified carbon, silicon, and oxygen as major components, corroborated by X-ray Diffraction (XRD) analysis indicating the presence of silicon oxide (SiO2), potassium oxide (K2O), and calcium oxide (CaO). Fourier Transform Infrared (FTIR) spectroscopy highlighted diverse functional groups on PPAC's surface. CO2 adsorption tests were conducted at 27°C and 40°C with varying pressures on PPAC particles of 150µm and 845µm sizes. Results revealed that CO2 adsorption capacity increased with escalating pressures. Remarkably, at 27°C, PPAC exhibited superior performance than at 40°C, attributed to a higher-pressure drop enhancing the driving force for CO2 adsorption. Larger particles (845µm) demonstrated higher adsorption capacity due to increased surface area, enhanced pore accessibility, and faster mass transfer. The Response Surface Methodology (RSM) conducted gave 2FI model as the most representative of the design data and showed high accuracy (R2=0.9973) and low error metrics (MSE=0.01697, RMSE=0.130269, MAE=0.109, MAPE=2.7244). The Adeq Precision value of 76.26 validated the model's reliability. Optimization using RSM yielded optimal CO2 adsorption values (9.69 mmol/g) at 27°C and 100 bars. PPAC emerges as a promising solution for CO2 capture, offering valuable prospects in mitigating emissions and addressing climate change challenges.