Optimization and kinetics of the desulfurization of diesel fuel via high shear mixing oxidation assisted by adsorption of sulfones onto chitosan-coated bentonite

ABSTRACT

Rapid increase in the worldwide consumption of fuel has resulted in environmental and health hazards arising from elevated concentrations of sulfur dioxide and sulfate particulate matter in the atmosphere. In this study, the reduction of the sulfur content in commercial diesel with an initial concentration of 1428 ppm was carried out via oxidative desulfurization (ODS) assisted by high shear mixing using hydrogen peroxide as oxidant and phosphotungstic acid as catalyst in combination with the fixed-bed adsorption of sulfur compounds onto chitosan-coated bentonite (CCB) and activated carbon (AC). The effects of mixing speed (8,000–12,000 rpm), oxidation temperature (60–80ºC), and oxidation time (20–40 min) on sulfur removal were analyzed using the response surface methodology based on the Box–Behnken Design. Results show that the maximum sulfur removal of 81.97% could be attained at the following optimum conditions: 12,000 rpm, 80°C, and 34 min. Fixed-bed studies illustrated that CCB (0.2 mm) has higher adsorption efficiency of 82.66% than AC of 63.24% in the removal of sulfones from diesel.

KEYWORDS:

• Adsorption
• box-behnken design
• diesel
• fixed bed adsorption
• mixing-assisted oxidative desulfurization

Acknowledgments

The authors would like to thank the Ministry of Science and Technology (Taiwan) (MOST 105-2221-E-041-002-MY3) and National Research Foundation (Korea) through Ministry of Education (No. 2016R1A6A1A03012812) for providing financial support for this research undertaking.

Additional information

Funding

This work was supported by the Ministry of Science and Technology [MOST 105-2221-E-041-002-MY3];National Research Foundation (Korea) [2016R1A6A1A03012812];