Preparation and Characterization of Pelleted and Powdered Activated Carbons Derived from Used Brewed Coffee

Abstract

The experimental study is the best way to find out the characteristics of activated carbon (AC) due to its very difficult definition based on its structural formulation or chemical analysis as an effect of its high degree of imperfection in the crystal structure. This experimental study’s objectives are to investigate the characteristics and the adsorption capacities of activated carbon generated from used brewed coffee. The carbonization procedure took place at a temperature of 600 °C. After being made into pellets and powder, the charcoal was heated to 600 °C and activated with the help of 150 mL of nitrogen flowing per minute. Thermogravimetric analyzer (TGA), scanning electron microscopy (SEM), and the adsorption isotherm test were all utilized in the characterization process. The results showed that for pelleted activated carbon (AC-Plt) and powdered activated carbon (AC-Pw), respectively, both activated carbons had average pore diameters in the mesopore category of 4.39 and 4.93 nm. In comparison to AC-Pw, AC-Plt has a larger specific pore surface area (105.857 cm3/g) and pore volume (0.164 cm3/g). The adsorption capabilities of AC-Plt, which has a bimodal pore size distribution, are greater than those of AC-Pw for nitrogen, CO2, and methylene blue. In this investigation, it was discovered that pelleted activated carbon was more suited for the adsorption of nitrogen, CO2, and methylene blue. HIGHLIGHTS The used brewed coffee was successfully converted into powdered and pelleted activated carbons using nitrogen as an activator agent through physical activation The use of natural binder to produce pelleted activated carbon undergoes pyrolysis during the activation process, producing gas that acts as an activating agent (e.g., CO2) so that nitrogen and CO2 work simultaneously and more effectively to develop more activated carbon pore structures Pelleted activated carbon has a higher specific pore surface area of 105.857 cm3/g, pore volume of 0.164 cm3/g, and better adsorption capabilities for nitrogen (75.252 cm3/g), CO2 (1.554 mmol/g) and methylene blue (1.215 mg/g) adsorptions than powdered activated carbon GRAPHICAL ABSTRACT