Adsorption Desulfurization of Liquid Fuel Using a Blend of Date Stones and Walnut Shells by Box–Behnken Design

ABSTRACT A specific microporous KOH/activated‐biochar (K/ BC ) was produced from a blend of date stones (DS) and walnut shells (WS) and used in the adsorptive desulfurization (ADS) of two types of model fuel DBT/n‐hexane (S‐hex), DBT/cyclohexane (S‐cyclohex). The equivalent mix of the DS and WS was carbonized at 500°C for 1 h at a heating rate of 50°C/min, followed by KOH activation via the optimized route. The BET surface area, total pore volume, and average pore diameter of the developing K/ BC were, respectively, 463.48 m 2 /g, 0.2265 cm 3 /g, and 1.9469 nm. The statistical study employing response surface methodology (RSM) revealed that temperature and dosage adsorbent had a major effect on DBT elimination. The ADS of S‐Hex was 97.8% compared with 99.05% for S‐cyclohex. The ADS from the studied models of fuel followed the Langmuir model of the adsorption isotherms and the pseudo‐second‐order model of kinetics. The K/ BC was recyclable and operative even after 4 cycles of reusability with a reasonable efficiency, demonstrating the said adsorbent could be advised for the ADS process at the industrial scale. As a whole, the developed K/ BC can be recommended as a powerful adsorbent for providing an ultra‐low sulfur fuel.