Synthesis of nanofluids composed of deep eutectic solvents and metal-modified MCM-41 particles as multifunctional promoters for fuel oil desulfurization

Compared with traditional hydrodesulfurization,new nonhydrodesulfurization methods have the advantage of a high removal efficiency for thiophene compounds under mild conditions.However,independent nonhydrodesulfurization technologies are faced with their own shortcomings,such as limitations of the desulfurization performance and regeneration of materials.To overcome these limitations,four nanofluids were prepared by dispersing different metal-modified MCM-41 particles in deep eutectic solvent as multifunctional promoters to develop a comprehensive desulfurization method.Based on the excellent adsorbability and high catalytic activity of the dispersed particles and the outstanding extractability of deep eutectic solvent in nanofluids,a high sulfur removal of 99.33%was achieved for model oil under mild conditions in 15 min.The nanofluids also showed excellent reusability due to their high structural stability.In addition,NF@Cu/Al-MCM-41-2.5%exhibited the best desulfurization performance among the prepared nanofluids.This result was obtained because the introduction of Al ions increased the number of acid sites and defect sites to improve the catalytic activity and adsorbability,and the best affinity of Cu/Al-MCM-41 for the deep eutectic solvent favored the reaction mass transfer.This work opens the door to the development of a comprehensive nonhydrodesulfurization method based on the design of nanofluid materials.

Oxidative desulfurization of dibenzothiophene over Fe promoted Co–Mo/Al_2O_3 and Ni–Mo/Al_2O_3 catalysts using hydrogen peroxide and formic acid as oxidants

This work reports the enhancing effect of a highly cost effective and efficient metal, Fe, incorporation to Co or Ni based Mo/Al2O3 catalysts in the oxidative desulfurization （ODS） of dibenzothiophene （DBT） using H2O2 and formic acid as oxidants. The influence of operating parameters i.e. reaction time, catalyst dose, reaction temperature and oxidant amount on oxidation process was investigated. Results revealed that 99% DBT conversion was achieved at 60℃ and 150 min reaction time over Fe-Ni-Mo/Al2O3. Fe tremendously enhanced the ODS activity of Co or Ni based Mo/Al2O3 catalysts following the activity order：Fe-Ni-Mo/Al2O3 〉 Fe-Co-Mo/Al2O3 〉 Ni-Mo/Al2O3 〉 Co-Mo/Al2O3, while H2O2 exhibited higher oxidation activity than formic acid over all catalyst systems. Insight about the surface morphology and textural properties of fresh and spent catalysts were achieved using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive X-ray （EDX） analysis, Atomic Absorption Spectroscopy （AAS） and BET surface area analysis, which helped in the interpretation of experimental data. The present study can be deemed as an effective approach on industrial level for ODS of fuel oils crediting to its high efficiency, low process/catalyst cost, safety and mild operating condition.