Oxidative Desulfurization Of Fuel Oil Research Articles

Remarkable Catalytic Performance of MoO(O2)2 Loaded in NH2‐UiO‐66 for Oxidative Desulfurization of Fuel Oil

AbstractA highly efficient oxidative desulfurization composite catalyst NH2‐Uio‐66‐Mo has been prepared and applied in the catalytic oxidative desulfurization. It was elucidated that Mo6+ could increase the oxygen vacancies and active sites on the catalyst and increase the pore size of UiO‐66. Meanwhile, the removal rate of dibenzothiophene (DBT) reached 99.2 % after 60 min under optimal conditions and remained above 90 % after 5 cycles, showing the composite catalyst's remarkable catalytic performance and satisfactory reusability NH2‐UiO‐66‐Mo. In addition, kinetic studies revealed that the desulfurization process can present a pseudo‐first‐order kinetic process. The apparent activation energy was 10.6 kJ/mol. Finally, in combination with oxides, possible oxidation pathways were identified.

Advances in Oxidative Desulfurization of Fuel Oils over MOFs-Based Heterogeneous Catalysts

Catalytic oxidative desulfurization (ODS) of fuel oils is considered one of the most promising non-hydrodesulfurization technologies due to the advantages of mild reaction conditions, low cost and easy removal of aromatic sulfur compounds. Based on this reason, the preparation of highly efficient ODS catalysts has been a hot research topic in this field. Recently, metal-organic frameworks (MOFs) have attracted extensive attention due to the advantages involving abundant metal centers, high surface area, rich porosity and varied pore structures. For this, the synthesis and catalytic performance of the ODS catalysts based on MOFs materials have been widely studied. Until now, many research achievements have been obtained along this direction. In this article, we will review the advances in oxidative desulfurization of fuel oils over MOFs-based heterogeneous catalysts. The catalytic ODS performance over various types of catalysts is compared and discussed. The perspectives for future work are proposed in this field.

Research Progress of Phase Transfer Catalysts Used in Oxidative Desulfurization of Fuel Oil

The removal of sulfur compounds from fuel oil has been a major concern of the fuel industry. Hydrodesulfurization (HDS) is the most common desulfurization method currently used in oil refineries. However, HDS requires high temperature and high pressure conditions, consumption of hydrogen, and the removal effect of thiophene sulfides is not ideal. In view of defects of HDS, nonhydrodesulfurization technologies have been developed. Oxidative desulfurization (ODS) is regarded as the most potential desulfurization technology to replace HDS in industry because of mild operating conditions and high desulfurization efficiency. However, most ODS reactions are performed in heterogeneous systems. The common problem is that the oxidant and sulfur-containing compounds cannot contact effectively. Phase Transfer Catalysts (PTCs) are a class of catalysts that can assist in the transfer of reactants, thereby increasing mass transfer and accelerating the reaction rate of the heterogeneous ODS system. In this review, we divide PTCs applied to ODS into quaternary ammonium salts PTCs, ILs PTCs, polymers PTCs, supported PTCs and reaction-controlled PTCs, and will systematically introduce and summarize the research progress of PTCs used in ODS system. It is pointed out that reaction-controlled PTCs have a broad prospect in ODS system. In addition, the synthesis and recovery of PTCs will be briefly described.

Synthesis of Defect-Rich Titanium Terephthalate with the Assistance of Acetic Acid for Room-Temperature Oxidative Desulfurization of Fuel Oil

The development of highly active oxidative desulfurization (ODS) catalysts is of practical importance for producing clean fuel oil. Recently, metal–organic frameworks (MOFs) have been attempted as ...

Oxidative Desulfurization of Fuel Oil at Room Temperature Catalyzed by Ordered Meso-macroporous HPW/SiO2

A serial of ordered meso-macroporous phosphotungstic acid (HPW) supported on SiO2 nanocomposites were successfully prepared by a homogeneous precipitation method, using monodispersed polystyrene (PS) microspheres and cationic surfactant as structure directing agent. These nanocomposites were used as catalysts for oxidative desulfurization (ODS) of model fuel. The materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption isothrem, X-ray diffraction (XRD), and Fourier transform infrared spectra (FTIR). The characterization results suggested that the as-prepared material possessed ordered meso-macroporous architectures with Keggin type phosphotungstic acid dispersed homogeneously in SiO2 matrix. Under the selected reaction conditions, dibenzothiophene (DBT) in model fuel can be removed within 2 h at room temperature (30 °C). In addition, only 1.2% of efficiency lose than the fresh catalyst even after 5 cycles.

Immobilization of Acidic Ionic Liquid on Silica Gel for Catalytic Oxidative Desulfurization of Fuel Oils(II): Desulfurization

A series of highly dispersed ionic liquid catalysts were used for the oxidation desulfurization of dibenzothiophene (DBT) in model oil in the presence of H2O2. The effects of the loading of [BMIM]HSO4immobilized, reaction time, temperature, O/S molar ratio and the dosage of catalysts on DBT removal were investigated in detail. The catalyst with the loading of [BMIM]HSO4was 25% exhibited the highest activity. The DBT removal of model oil can reach 99.9% in 5 h at 60 °C, O/S molar ratio of 10, Vmodeloil=10mL, mcatalysts=2.00g. The catalysts can be easily recycled and can be recycled 2 times without a significant decrease in activity.

Immobilization of Acidic Ionic Liquid in Silica Gel for Catalytic Oxidative Desulfurization of Fuel Oils(I): Preparation and Charaterization of Catalysts

A series of highly dispersed ionic liquid catalysts were prepared by immobilized acidic ionic liquid [BMIM]HSO4 in silica gel through sol-gel methods. The structures and properties of the catalysts were characterized by FT-IR, SEM and XRD. The results showed the [BMIM]HSO4 had been successfully confined or encapsulated in a silica-gel matrix.

Oxidative Desulfurization of Fuel Oils

Several attractive approaches toward oxidative desulfurization of fuel oils, such as using H 2 O 2 /organic acids, H 2 O 2 /heteropolyacid, H 2 O 2 /Ti-containing zeolites, and other non-hydrogen peroxide systems (e.g., t -butyl hydroperoxide etc.) are reviewed. A new alternative oxidative desulfurization process using emulsion catalysts was developed mainly by our group, is introduced in detail. Limitations because of interphase mass transfer are greatly reduced in the emulsion reaction medium. The amphiphilic emulsion catalysts can selectively oxidize the sulfur-containing molecules present in diesel to their corresponding sulfones when using H 2 O 2 as the oxidant under mild conditions. The sulfones in the oxidized fuel oils can be removed by a polar extractant. The sulfur level of a prehydrotreated diesel can be lowered from a few hundred μg/g to 0.1 μg/g after oxidation and subsequent extraction whereas the sulfur level of a straight-run diesel can be decreased from 6000 to 30 μg/g after oxidation and extraction. 摘要：综述了燃油的氧化脱硫, 包括一些具有吸引力的氧化脱硫方法, 如 H 2 O 2 /有机酸, H 2 O 2 /杂多酸, H 2 O 2 /含钛分子筛和其它非过氧化氢体系 (如叔丁基过氧化物等). 对本课题组开发的新型乳液催化氧化脱硫体系进行了详细的介绍. 在乳液体系中, 界面间的传质限制被大大降低. 在温和条件下, 双亲性乳液催化剂可以将柴油中的含硫化合物选择氧化成其相应的砜类化合物. 氧化得到的砜可以使用极性萃取剂将其从油品中除去. 经过氧化和萃取之后, 加氢柴油中的硫含量可以从几百 μg/g 降低至 0.1 μg/g, 而直馏柴油中的硫含量则可以从 6000 μg/g 降低至 30 μg/g. The sulfur-containing compounds in diesel can be oxidized to their corresponding sulfones by the amphiphilic emulsion catalysts under mild conditions, and the sulfones can be removed by a polar extractant.

Ultra-deep Oxidative Desulfurization of Fuel Oil Catalyzed by Dawson-type Polyoxotungstate Emulsion Catalysts

The Dawson-type polyoxotungstate emulsion catalysts Q18P2W18, Q18P2W17, and Q18P2W12 were successfully synthesized and characterized by IR and 31P MAS NMR. They were used for the oxidation of sulfur-containing compounds such as 4,6-dimethyldibenzothiophene (4,6-DMDBT), dibenzothiophene (DBT), benzothiophene (BT), and 2,5-dimethythiophene (2,5-DMT) with H2O2 as an oxidant under mild conditions. The activity of the catalysts decreased in the order: Q18P2W12 > Q18P2W17 > Q18P2W18. The oxidative reactivity of the sulfur-containing compounds decreased according to DBT > 4,6-DMDBT > BT > 2,5-DMT. BT was completely oxidized into the corresponding sulfone upon catalysis by Q18P2W12 at 60 °C for 30 min. ：合成了 Dawson 型聚氧钨酸乳液催化剂 Q18P2W18, Q18P2W17, 和 Q18P2W12. 采用红外光谱和固体核磁技术对其进行了表征, 并用于温和条件下 H2O2 氧化 4,6-二甲基二苯并噻吩 (4,6-DMDBT)、二苯并噻吩 (DBT)、苯并噻吩 (BT) 和 2,5-二甲基噻吩 (2,5-DMT) 等含硫化合物的反应中. 结果表明, 各催化剂的活性大小顺序为 Q18P2W12 > Q18P2W17 > Q18P2W18. 含硫化合物的氧化活性顺序为 DBT > 4,6-DMDBT > BT > 2,5-DMT. 在 60 °C 反应 30 min 内, Q18P2W12 催化剂能够催化氧化 BT 完全转化成相应的砜.

Oxidative Desulfurization of Fuel Oil with Hydrogen Peroxide Catalyzed by Keggin-type Polyoxotungstate in a DC Magnetic Field

The oxidation of sulfur-containing compounds was conducted in a DC magnetic field-assisted system, composed of model compound or diesel, 30 wt% hydrogen peroxide, and an iron mono-substituted Keggin-type heteropolytungstate [(C4H9)4N]4 [PW11Fe(H2O)O39] catalyst. By combining oxidative desulfurization (ODS) in a magnetic field and acetonitrile extraction, when magnetic field intensity was at 17.3 mT, the removal efficiency of the model compound dibenzothiophene (DBT) in petroleum ether with 1,000 ppm S can reach 98% at 70°C within 30 min with O/S ratio = 3 and catalyst dosage 5%, with 2% increase over that without magnetic field assistance. Under the same reaction conditions, the sulfur level of diesel oil was reduced from 5,647 to 508 ppm. This shows that the DC magnetic field facilitates the oxidation of sulfur-bearing compounds, which allowed greater sulfur removal efficiency under milder reaction conditions.

Oxidative Desulfurization of Fuel Oil by Pyridinium-Based Ionic Liquids

In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF4 was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF4 has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H2O2) = 1:1:0.4, temperature 55 °C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration.

Deep Oxidative Desulfurization of Fuel Oils Catalyzed by Decatungstates in the Ionic Liquid of [Bmim]PF6

Three decatungstates with short carbon chains as the cations, such as tetrabutylammonium decatungstate ([(C4H9)4N]4W10O32), tetramethylammonium decatungstate ([(CH3)4N]4W10O32), and benzyltriethylammonium decatungstate ([(C2H5)3NC7H7]4W10O32), were synthesized and then used as a catalyst in the extractive catalytic oxidative desulfurization (ECODS) system in the ionic liquid (IL) of [Bmim]PF6, and hydrogen dioxide (H2O2) was used as an oxidant. During the optimized process, the sulfur level in the model oil (1000 ppm S) can be reduced to 8 ppm, which is consistent with the standards of deep desulfurization. The temperature, the reaction time, and the amount of H2O2 and catalyst, as well as the type of the cations of decatungstates, all played vital roles in desulfurization efficiency, which were studied in detail to optimize the reaction conditions. The system could be recycled five times before the sulfur removal decreased sharply.

Oxidative Desulfurization of Fuel Oil: Modeling Based on Artificial Neural Network

Oxidative desulfurization of fuel oil was investigated using a process consisting of oxidation and distillation steps. In the oxidation step, various organic carboxylic acid/H2 O2 systems, especially acetic acid/H2 O2, were used as oxidant. They oxidize both easy and refractory sulfur compounds and convert them into oxidized sulfur compounds. The oxidized sulfur compounds are finally removed from fuel oil by distillation in the presence of water. The sulfur content of fuel oil was decreased to levels as low as 20 ppm (up to 90%) in a short contact time, ambient temperature, and atmospheric pressure. The results showed that applying this process did not have any deleterious influence on the distillation characteristic, composition, and content of fuel oil that was examined. An artificial neural network, using back propagation (BP), was also utilized for modeling oxidative desulfuration process of fuel oil. The comparison between the output of ANN modeling and the experimental data showed satisfactory agreement.