Desulfurization Of Benzothiophene Research Articles

Oxidative Desulfurization of Benzothiophene by Persulfate and Cu-Loaded g-C3 N4 via the Polymerization Pathway

Oxidative Desulfurization of Benzothiophene by Persulfate and Cu-Loaded g-C₃ N₄ via the Polymerization Pathway

Preparation of highly active g-C3N4 supported amphiphilic quaternary ammonium phosphotungstate catalyst for solvent-free oxidative desulfurization of benzothiophene

Preparation of highly active g-C3N4 supported amphiphilic quaternary ammonium phosphotungstate catalyst for solvent-free oxidative desulfurization of benzothiophene

Evolution of nickel species in reactive adsorption desulfurization of benzothiophene

Reactive adsorption desulfurization (RADS) is one of the main means for the ultra-deep desulfurization of gasoline. Metallic Ni is normally assumed as the main RADS active site, and NiSx is the intermediate phase during RADS process. In this work, the evolution of nickel species, especially NiSx, were examined over NiO/ZnO-Al2O3-SiO2 and NiSO4/ZnO-Al2O3-SiO2 adsorbents. Results showed that both of the adsorbents performed high desulfurization efficiency. However, differences of the activation mechanism were observed. For the NiO adsorbent, BT (benzothiophene) can be adsorbed onto the reduced Ni sites, then the C-S bond ruptures to form NiSx. For the NiSO4 adsorbent, NiSO4 phase are firstly self-sulfied to NiSx in the presence of hydrogen or n-heptane. XRD and XPS results presented that NiO and NiSx could be found after the RADS reaction in two spent adsorbents. As same as the sulfurization of NiO into NiSx is a primary condition for the RADS reaction, NiSO4 can be partly in situ self-sulfied to NiSx. To verify the self-sulfidation of NiSO4, H2 pretreatment showed that there were NiO and NiSx species on the pretreated NiSO4/ZnO-Al2O3-SiO2 adsorbent, and the desulfurization performance of the adsorbent was obviously improved, indicating that the formation and accumulations of NiSx could promote the RADS activity. At last, the RADS mechanism of BT on two kinds of adsorbents are presented and discussed based on the assumption of NiO and NiSx as the main active components.

Oxidative Desulfurization of Benzothiophene by Persulfate and Cu-Doped G-C3n4 Via the Polymerization Pathway

Oxidative Desulfurization of Benzothiophene by Persulfate and Cu-Doped G-C3n4 Via the Polymerization Pathway

Novel flower-like (Bi(Bi2S3)9I3)2/3 nanostructure as efficient photocatalyst for photocatalytic desulfurization of benzothiophene under visible light irradiation

Here, we report the preparation of hierarchical flower-like (Bi(Bi2S3)9I3)2/3 nanostructures that acts as a strong photocatalyst in the desulfurization of benzothiophene. We optimized the reaction time, type of capping agent and reflux temperature to tune the shape of porous flower-like (Bi(Bi2S3)9I3)2/3 nanostructures to achieve the highest desulfurization performance. We investigated the characteristic shape, size, purity, and optical response of the flower-shape nanostructures using XRD, EDS, FESEM, UV–Vis-DRS analysis. The flower-like (Bi(Bi2S3)9I3)2/3 nanostructures showed a significant photocatalytic property in desulfurization of benzothiophene as a model fuel. The hierarchical flower-like (Bi(Bi2S3)9I3)2/3 photocatalyst with an energy gap of 1.15 eV, exhibits a 92% photocatalytic desulfurization performance after 2 h of visible light irradiation. The (Bi(Bi2S3)9I3)2/3 nanostructures show a high photocatalytic reproducibility after 4 rounds of exposure. We proposed a photo-oxidation mechanism based on the active species scavenging, which revealed the role of photo-produced h+ and O2− species as essential in the photocatalytic desulfurization process. These findings provide a new prospect and design strategy for the development of efficient photocatalysts in desulfurization process.

Synthesis BiVO4 modified by CuO supported onto bentonite for molecular oxygen photocatalytic oxidative desulfurization of fuel under visible light

A highly photocatalytic activity of bismuth vanadate (BiVO4) modified by CuO was synthesized loaded onto the bentonite (BTT) and applied to photocatalytic oxidative desulfurization of model oil. The photocatalyst was characterized by XRD, SEM, EDS, FT-IR, XPS and UV–vis DRS. The influences of the mass ratio of cata./model oil, the flow rate of molecular oxygen and the irradiation time on the photocatalytic oxidative desulfurization of model oil were investigated by using molecular oxygen as the oxidant. The sulfur removal performances and products of the photocatalytic oxidative desulfurization of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) in model oil under visible light were also discussed. The results showed that the photocatalytic activity of CuO modified BiVO4/BTT for organic sulfur compounds under visible light was significantly higher than that of BiVO4 and BiVO4/BTT. Its oxidative desulfurization reactions for BT, DBT, 4-6DMDBT were the pseudo-first-order reaction, and the desulfurization activity as well as apparent activation energy followed the order of DBT > 4,6-DMDBT > BT. The photocatalytic oxidative desulfurization mechanism of CuO-BiVO4/BTT was analyzed through the calculated band gap, valence band and conduction band position. The recycling experiment presented that DBT removal by CuO-BiVO4/BTT still reached 81.5% after ten cycles.

Evolution of Nickel Species in Reactive Adsorption Desulfurization of Benzothiophene

Reactive adsorption desulfurization (RADS) is one of the main means for the ultra-deep desulfurization of gasoline. Metallic Ni is normally assumed as the main RADS active site, and NiSx is the intermediate phase during RADS process. In this work, the evolution of nickel species, especially NiSx, were examined over NiO/ZnO-Al2O3-SiO2 and NiSO4/ZnO-Al2O3-SiO2 adsorbents. Results showed that both of the adsorbents performed high desulfurization efficiency. However, differences of the activation mechanism were observed. For the NiO adsorbent, BT (benzothiophene) can be adsorbed onto the reduced Ni sites, then the C-S bond ruptures to form NiSx. For the NiSO4 adsorbent, NiSO4 phase are firstly self-sulfied to NiSx in the presence of hydrogen or n-heptane. XRD and XPS results presented that NiO and NiSx could be found after the RADS reaction in two spent adsorbents. As same as the sulfurization of NiO into NiSx is a primary condition for the RADS reaction, NiSO4 can be partly in situ self-sulfied to NiSx. To verify the self-sulfidation of NiSO4, H2 pretreatment showed that there were NiO and NiSx species on the pretreated NiSO4/ZnO-Al2O3-SiO2 adsorbent, and the desulfurization performance of the adsorbent was obviously improved, indicating that the formation and accumulations of NiSx could promote the RADS activity. At last, the RADS mechanism of BT on two kinds of adsorbents are presented and discussed based on the assumption of NiO and NiSx as the main active components.

Hydrodesulfurization of benzothiophene on Ni2P surface

The study of benzothiophene hydrodesulfurization reaction path contribute to clarifying the mechanism of hydrodesulfurization (HDS) of heavy oil. In this work, experiments and simulations were combined to study the reaction pathway of benzothiophene hydrodesulfurization catalyzed by Ni2P. In experimental part, Ni2P catalyst was prepared and characterized. Then, the catalytic property of the catalyst for benzothiophene hydrodesulfurization was evaluated. The substance types and contents in the liquid phase products were detected to verify the accuracy of the simulation results. Dmol3 module of the Materials Studio (MS) simulation software was used to simulate the adsorption and hydrodesulfurization of benzothiophene on the surface of Ni2P catalyst and explore the most probable reaction path. The results showed that the most stable adsorption configuration of benzothiophene on the surface of Ni2P was Ni-hcp. In addition, indirect desulfurization of benzothiophene was more advantageous than direct desulfurization. The most possible path for indirect desulfurization was Benzothiophene (BT) – Dihydrobenzothiophene (DHBT) – C8H9S2 – 2-phenylethyl mercaptan (PET) – Ethylbenzene (EB), while that of direct desulfurization was Benzothiophene (BT) – C8H7S2 – Styrene thiol (CMT) – Styrene (ST) – Ethylbenzene (EB).

Kinetics of Triphase Extractive Oxidative Desulfurization of Benzothiophene with Molecular Oxygen Catalyzed by HPA‐5

AbstractThe triphasic aerobic extractive desulfurization of benzothiophene (BT) using an aqueous H8[PV5Mo7O40] solution as catalyst and O2 as oxidant was investigated. A time‐resolved analysis of all reaction products in the gas, organic and aqueous phase, is given. The organic sulfur in BT is mainly converted to sulfuric acid. Mass transport limitations can be excluded. The reaction orders are 1 with regard to BT, and 0.5 both for HPA‐5 and O2. Calculated data derived from this mechanism with a power law kinetic approach show good agreement to the experimental data for conversions below 60 %. At higher BT conversions, significant deviations are found, suggesting that acidic products formed in the BT oxidation affect the catalyst and therefore the initial kinetics of the BT oxidation.

Evaluation of the membrane efficiency of both Nafion and sulfonated poly (ether ether ketone) using electrochemical membrane reactor toward desulfurization of a model diesel fuel

In this paper, the desulfurization of a model diesel fuel containing thiophene and/or benzothiophene using an electrochemical membrane reactor was studied using commercial Nafion and synthesized sulfonated poly ether ether ketone (SPEEK) with the same 40wt.% Pt/C electrocatalyst. Thiophene and benzothiophene desulfurization under different current density and constant total charge were investigated toward optimum desulfurization conditions. Dihydrobenzothiophene (DHBT) and thiophene as hydrogenation products and H2S as the product of desulfurization were detected. Desulfurization efficiency of 85% at 20mAcm−2 and 75% at 30mAcm−2 was obtained for thiophene using Nafion and SPEEK respectively, while benzothiophene desulfurization efficiency was about 70% and 65% related to Nafion and SPEEK. Also, the maximum yield of 85% for DHBT at 40mAcm−2. Based on the indirect calculation, the H2S yield approaches 98% and 96% for Nafion and SPEEK system at about 100% selectivity in electroreduction of benzothiophene.

VOHPO4.5H2O/KIT-6 composites: Preparation and their application in extractive and catalytic oxidation desulfurization of benzothiophene and dibenzothiphene

Abstract The catalytic activity of vanadyl hydrogen phosphate hemihydrate (VPO) for deep desulfurization of a model fuel was explored. For this purpose, a series of composites containing different amounts of vanadyl hydrogen phosphate and well-ordered mesoporous silica (KIT-6) were prepared and their structural and textural characterizations were carried out using SEM, TEM, ICP-AES, FT-IR, N2 adsorption-desorption, XPS and XRD techniques. It was found that the catalyst with maximum vanadium phosphate loading (VPKA) shows the highest catalytic activity in dibenzothiophene (DBT) removal through oxidative desulfurization (ODS) process. Different reaction conditions such as temperature, the mole ratio of H2O2:DBT, and catalyst loading were investigated in the catalytic system.

Desulfurization of benzothiophene from model diesel fuel using experimental (dynamic electroreduction) and theoretical (DFT) approaches

In this paper, desulfurization of benzothiophene from model diesel fuel was investigated experimentally using dynamic electroreduction method. Also based on possible reaction pathway of benzothiophene electroreduction, the corresponding reduction potential was calculated by Gibbs free energy of relative reaction derived from DFT calculation and confirmed with experimental studies. This calculation revealed that the appropriate reduction potential for direct desulfurization of benzothiophene to Styrene is −0.147 V.Finally, bulk desulfurization of emulsified model-diesel was done at best operational conditions (i.e., 0.3 V adsorption potential, −0.15 V reduction potential and frequency of 10 Hz). Initial and desulfurized fuels were analyzed with Fourier transform infrared spectroscopy, and GC-MS analysis showed the styrene and dihydrobenzothiophene were products of BT desulfurization. The total sulfur content was measured by the total elemental sulfur analyzer which revealed that 23.3%, 38.4% and 48.2% of sulfur content was converted to H2S after 4 h, 6 h, and 8 h respectively.

Superoxide Ion as Oxidative Desulfurizing Agent for Aromatic Sulfur Compounds in Ionic Liquid Media

The generation of superoxide (O2•–) in ionic liquids (ILs) has been used to destroy hazardous materials. In this study, O2•– was used for the oxidative desulfurization of benzothiophene (BT) and dibenzothiophene (DBT) in two ILs as reaction media. The O2•– was released by dissolving potassium superoxide in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [BMPyrr][TFSI] and n-methoxyethyl-n-methylmorpholinium bis(trifluoromethylsulfonyl)imide [MOEMMor][TFSI]. The highest conversion percentages for BT in [MOEMMor][TFSI] and [BMPyrr][TFSI] were 99.4 and 96.6%, respectively, and the highest conversion percentages for DBT in [MOEMMor][TFSI] and [BMPyrr][TFSI] were 98.3 and 94.3%, respectively. As the temperature was increased, the reaction of the O2•– with BT and DBT was enhanced significantly. The BT was converted easier than DBT due to the nucleophilic characteristic of the O2•– and the higher electron density of the sulfur atom in DBT than that in BT. In addition, the ILs had a clear effect o...

Catalytic Performance of Ammonium Salt of Molybdenum Heteropoly Acid Supported Silica for Oxidative Desulfurization of Benzothiophene, Dibenzothiophene and 4,6-Dimethyldibenzothiophene in Model Oil

Catalytic Performance of Ammonium Salt of Molybdenum Heteropoly Acid Supported Silica for Oxidative Desulfurization of Benzothiophene, Dibenzothiophene and 4,6-Dimethyldibenzothiophene in Model Oil

Optimization analysis of mixing-assisted oxidative desulfurization of model sulfur compounds using commercial ferrate(VI)

Mixing-assisted oxidative desulfurization of benzothiophene (BT) and dibenzothiophene (DBT) was investigated using commercial ferrate(VI). The effect of operating parameters such as temperature (50...

Facile Oxidative Desulfurisation of Benzothiophene Using Polyoxometalate H4[α-SiW12O40]/Zr Catalyst

A highly active catalyst H4[α-SiW12O40]/Zr based polyoxometalete Keggin type was prepared by wet impregnation method and was characterized by FTIR spectroscopy, X-ray diffractometer, surface textural property by SEM, and analysis of porosity by BET method. H4[α-SiW12O40]/Zr was successfully synthesized and showed uniform properties with block solid structure which was applied as heterogeneous stable catalyst for oxidative desulfurization of benzothiophene under simple and mild condition using H2O2 as oxidant. Facile conversion of benzothiophene to sulfone by using heterogeneus H4[α-SiW12O40]/Zr catalyst up to 99% was observed to show the active catalytically. Keggin H4[α-SiW12O40]/Zr cage structure after reaction was different from fresh catalyst which was indicated by the instability of H4[α-SiW12O40]/Zr under reaction condition. © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

Deep oxidative desulfurization of benzothiophene and dibenzothiophene with a peroxophosphotungstate–ionic liquid brush assembly

A novel, efficient and reusable heterogeneous catalytic assembly of peroxophosphotungstate held in an ionic liquid brush was synthesized and an extraction and catalytic oxidative desulfurization (ECODS) procedure was developed for a model oil of benzothiophene (BT) and dibenzothiophene (DBT) using 30 wt% hydrogen peroxide as terminal oxidant and methanol as solvent under mild conditions. Several factors that affect sulfur removal were investigated in detail. The highest sulfur removal can reach 100% for BT in 7 h at 70 °C when the molar ratio of H2O2, S and catalyst is 10:1:0.025. The sulfur removal for DBT can also reach 100% in 4 h at 50 °C with the same molar ratio of H2O2, S and catalyst. The experimental results demonstrate that this ECODS process has no apparent scale‐up effect. The catalyst can be easily recovered (via simple filtration) and recycled five times without a significant decrease in activity. Copyright © 2015 John Wiley & Sons, Ltd.

Catalytic oxidative desulfurization of benzothiophene using silica-supported heteropolyacid catalyst: activity, deactivation and regeneration of the catalyst

A series of silica-supported heteropolyacid catalysts were prepared by the hydrothermal dispersion and ultrasonic impregnation methods, using phosphotungstic acid as active component and HMS molecular sieve as support. The catalytic stability of catalysts in the oxidative desulfurization of benzothiophene has been investigated. The results show that the sulfur removal of the two catalysts decreased from 97.81 and 95.63 to 81.28 and 75.3 % after eight cycles. The fresh and spent catalysts were characterized by Fourier transform infrared spectra, N2 adsorption, X-ray diffraction and transmission electron microscopy. The main results indicate that the deactivation process of the catalysts went through two stages, i.e., the dissolution of active component is the main factor at prophase and the adsorption of N-hexadecane and sulfone is the primary reason at anaphase. Furthermore, the former is an irreversible deactivation and the latter is a reversible deactivation which can be regenerated by solvent extraction.

Theoretical studies on the desulfurization of benzothiophene (thianaphthene) and thienothiophene (thiophthene) by carbon–sulfur bond cleavage: binuclear iron carbonyl intermediates

The lowest energy (C8H6S)Fe2(CO)nand (C6H4S2)Fe2(CO)nstructures (n= 6, 5) derived from benzothiophene and thienothiophene, respectively, have an iron atom inserted into C–S bond of the ligand thiophene ring.

Catalytic Desulfurization of Benzothiophene Using Keggin Type Polyoxometalates as catalyst

Performance of catalytic desulfurization of benzothiophen (BT) was studied using polyoxometalates as catalyst. Polyoxometalates H3[a-PW12O40] and H4[a-SiW12O40], have different heteroatom in Keggin structure and catalytic activities. Polyoxometalates H3[a-PW12O40] and H4[a-SiW12O40] have high crystallinity with homogeneous distribution particles. Desulfurization of BT using polyoxometalates H3[a-PW12O40] and H4[a-SiW12O40] resulted % conversion up to 99% for 3 h reaction time and at temperature 40 oC. Application of polyoxometalates H3[a-PW12O40] and H4[a-SiW12O40] for crude oil desulfurization showed % conversion of 4-88%. The main functional groups of polyoxometalates still retained after catalytic desulfurization indicated the stability of polyoxometalate compounds