Utilization of cocoa pod husk waste biomass for post-combustion CO2 adsorption

Abstract

Biomass-derived activated carbon for carbon dioxide (CO2) post-combustion has been drawing attention because they are cost-effective and environment-friendly. In this study, activated carbon was prepared from cocoa pod husk waste (COP) biomass for CO2 adsorption. The COP was pyrolyzed and activated using potassium hydroxide (KOH). The activated carbon prepared was characterized using scanning electron microscopy (SEM), Scanning Electron Microscopy- Energy Dispersive Spectroscopy and Fourier transform infrared spectroscopy (FTIR) analysis. The performance of the activated carbons prepared for CO2 was evaluated using a CO2 gas analyzer. Optimization of the adsorption process of CO2 was carried out by varying some important variables affecting the adsorption process. Results showed activated carbon prepared has a good pore structure with high carbon content that supported CO2 adsorption. The Freundlich model provided the best fit with the experimental data while data fitted well to pseudo-second-order kinetics with an adsorption capacity of 6.5 mg/g. The optimal condition for CO2 adsorption, was an adsorption time of 1 min, a Carbonization temperature of 700 °C, and Bed height of 5 cm, and % CO2 removal of 99.5%. The study revealed (COP) biomass as a suitable activated carbon precursor for CO2 capture.