Parametric analysis on the sulfone adsorption of using iron impregnated bentonite

Abstract Sulfur left in liquid fuel is oxidized during combustion and released into the atmosphere, contributing to the worsening of global warming. To address this, oil refineries make use of hydrodesulfurization (HDS) to reduce sulfur content in the fuel. Alternatives to HDS are being studied due to its extreme operating conditions. An alternative for treating sulfur in fuel is oxidative desulfurization, which converts sulfur to sulfones and can be extracted using adsorption methods. This study focuses on the use of bentonite modified with Fe 3+ to improve its adsorptive performance for removing dibenzothiophene sulfone (DBTO) in model oil. The prepared Fe 3+ -bentonite adsorbents resulted in lower removal of sulfur compared to raw bentonite. This is due to Fe 3+ being a hard acid, thus lowering the affinity of bentonite in adsorbing DBTO, which is a soft base. Three parameters were varied in this study, namely adsorption time, adsorbent dosage, and temperature. Results showed that DBTO removal increased with adsorption time as the DBTO molecules occupy more adsorption sites. Increasing adsorbent dosage also increases sulfur removal as it introduces more reaction sites for DBTO removal. The DBTO and bentonite system was also found to be endothermic as desulfurization increased with the temperature rise. With the data collected in this study, it is recommended to explore the possible upscaling of adsorptive desulfurization.