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

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 degrees 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 pHPZC. 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 degrees 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.