Adsorptive removal of dibenzothiophene from model fuel over activated carbon developed by KOH activation of pinecone: Equilibrium and kinetic studies

Abstract

Activated carbon (AC) was developed from pinecone using KOH as an activator to eliminate dibenzothiophene (DBT) from a synthetic model of gasoline fuel. The best sample was the AC prepared, employing a 1.5:1 KOH: feed impregnation ratio at 750°C for 1 h. Thus, it was tested in the adsorptive elimination of DBT from the fuel after being identified by X‐ray diffraction (XRD), field‐emission scanning electron microscopy (FESEM), energy dispersive X‐ray (EDX), N₂ adsorption–desorption isotherms, pore volume distribution, Fourier transform infrared spectroscopy (FTIR), total basic and acid groups, and pH_PZC. The as‐obtained AC exhibited a Brunauer–Emmett–Teller (BET) surface area of 478.89 m²/g with an average pore size of 2.0 nm, indicating its micropores structure. A removal performance of 97.90% was obtained using 0.30 g of AC at 20°C for 30 min, while the adsorptive capacity amounted to 34.38 mg/g as per the Langmuir isotherm. The as‐synthesized AC exhibited a good adsorptive performance for eliminating S compounds from commercial gasoline (42.11%) under the optimal experimental conditions, which increased to 88.16% with increasing the mass of AC implemented in the adsorption process. The adsorption of DBT through the fixed‐bed approach was also adopted, and the results at various flow rates of the effluent through fixed bed of the AC were close to that obtained via the batch‐adsorption system. The regenerated AC exhibited excellent adsorptive performance for DBT until 5 cycles of reuse, reflecting the effectiveness of the obtained AC. Finally, the Langmuir adsorption isotherm and pseudo‐second‐order kinetics model best described the DBT adsorption by the AC developed from pinecone.