Polyoxometalate-based silica-supported ionic liquids for heterogeneous oxidative desulfurization in fuels

Abstract

With the aim of deep desulfurization, silica-supported polyoxometalate-based ionic liquids were successfully prepared by a one-pot hydrothermal process and employed in heterogeneous oxidative desulfurization of various sulfur compounds. The compositions and structures of the hybrid samples were characterized by various methods such as FT-IR, XPS, Raman, UV-Vis, wide-angle XRD and N 2 adsorption-desorption. The experimental results indicated that the hybrid materials presented a high dispersion of tungsten species and excellent catalytic activity for the removal of 4,6-dimethyldibenzothiophene without any organic solvent as extractant, and the sulfur removal could reach 100.0% under mild conditions. The catalytic performance on various substrates was also investigated in detail. After cycling seven cycles, the sulfur removal of the heterogeneous system still reached 93.0%. The GC-MS analysis results demonstrated that the sulfur compound was first adsorbed by the catalyst and subsequently oxidized to its corresponding sulfone.

Oxidative Desulfurization of Liquid Fuels Using Polyoxometalate-Based Catalysts: A Review

“…Li et al 192 examined the oxidative desulfurization of model oils using 30% H 2 O 2 as the oxidant and an Keggin-type Zhang et al 193 proposed that a catalytic system consisting of 0.1 [C 4 mim] 3 PMO/SiO 2 -250 (0.01g) and 30% H 2 O 2 could remove 100% of S-compounds (250 ppm) within 1 h at 60 °C. The reactivity of various sulfur-containing compounds (C 4 -IL) in the ordered mesoporous silica (OMS) and employed this catalyst for the oxidative desulfurization of a model fuel using H 2 O 2 as the oxidant.…”

“…Zhang et al proposed that a catalytic system consisting of 0.1­[C 4 mim] 3 PMO/SiO 2 -250 (0.01g) and 30% H 2 O 2 could remove 100% of S-compounds (250 ppm) within 1 h at 60 °C. The reactivity of various sulfur-containing compounds decreased in the following order: 4,6-DMDBT > 4-MDBT > DBT > BT.…”

Desulfurization of Diesel Using Ionic Liquids: Process Design and Optimization Using COSMO-Based Models and Aspen Plus

“…Various researchers have demonstrated the use of ILs in desulfurization of diesel as a promising and an environmentally benign technology . Several techniques have been investigated, including extractive desulfurization (EDS), oxidative desulfurization (ODS), combined extractive and oxidative desulfurization (ECODS), and desulfurization using immobilized ILs. − The main factors that influence the results obtained from each technique include the length of the alkyl chain of the IL cation, the type of cation and anion, temperature, pressure, and time. What all these techniques have in common is their superior ability to extract high-molecular-weight sulfur compounds, such as BT and DBT, at mild operating conditions relative to those of conventional HDS.…”

Aerobic oxidative desulfurization via magnetic mesoporous silica-supported tungsten oxide catalysts

“…However, H 2 O 2 has some shortcomings such as strict transportation requirements and high cost. Moreover, H 2 O 2 as the oxidant has the biphasic problem of the mass transfer, thus decreasing the desulfurization efficiency (Li et al 2019;Zhang et al 2018). To overcome these shortcomings, O 2 has been applied as alternative oxidant in oxidative desulfurization process, due to its low cost, easy availability and high environmental safety.…”