Residual Sulfur Content Research Articles

Impact of Sulfate Adsorption on Particle Morphology during the Precipitation of Ni-Rich Hydroxide Precursors for Li-Ion Battery Cathode Active Materials

Nickel-cobalt-manganese-hydroxides (NixCoyMnz(OH)2, with x+y+z = 1) are utilized as precursor for lithium-ion battery cathode active material (CAM). The physical properties and electrochemical performance of CAM are affected by the morphology, crystallinity and impurity content of the associated NixCoyMnz(OH)2 (with x+y+z = 1) employed for the CAM synthesis. To promote the mechanistic understanding of the NixCoyMnz(OH)2 (with x+y+z = 1) formation, the coprecipitation pH23 °C-value was systematically varied from 8.6–12.7 during the synthesis of Ni0.8Co0.1Mn0.1(OH)2, and the obtained powders were characterized by elemental analysis. A dependency of residual sulfur content and crystallinity of the obtained Ni0.8Co0.1Mn0.1(OH)2 on the pH-value in relation to the point-of-zero-charge (pzc) is revealed. This result is rationalized by a pH-dependent sulfate adsorption equilibrium. Furthermore, a suppression of the growth along the (001) plane of the crystallites due to sulfate adsorption is identified. This in turn governs the vertical primary particle size and thus the porosity of the secondary particles, which was verified by substituting the sulfate ion of the metal feed by nitrate or acetate. Adsorption/desorption experiments demonstrate the possibility to decouple secondary particle morphology and residual impurity content. The demonstrated relationships allow formulating design strategies to tailor the NixCoyMnz(OH)2 (with x+y+z = 1) morphology and its impurity content for CAM synthesis.

Synthesis of ultrafine (Mo,W)Si2 composite powders from high purity molybdenum concentrate

(Mo,W)Si2 composite powders with the grain size of about 1 ?m were synthesized at 1150? for 2 h. The high purity molybdenum concentrate (with the main component of MoS2), W and Si powders were utilized as raw materials and lime as desulfurizer. The graphite felt was laid between the compact (made of MoS2, W and Si) and the lime to facilitate the separation of the produced composite powders from desulfurization product. The phase composition, microstructure evolution, and residual sulfur content during the silicothermic reduction reaction were evaluated. The experimental results showed that the reaction could be completed after a reaction time of 1150? for 2 h, and the residual sulfur content of the product was 0.087 wt.%. It was concluded that the interactions between Si and the intermediate products of SiS and SiS2 are crucial for the preparationof (Mo,W)Si2 composite powders at low temperatures. The preparation process could be divided into three stages: solid state reactions between MoS2, W and Si to produce MoSi2, WSi2 and gaseous SiS; gas-solid reaction between MoS2, W and gaseous SiS to generate MoSi2, WSi2 and gaseous SiS2; and gas-solid reaction between gaseous SiS2 and Si to form SiS gas. With this short flow process, fine-grained (Mo,W)Si2 composite powders can be produced at low cost at low temperature, which has great application potential.

Synthesis and characterization of lanthanum-modified pseudoboehmite - The precursor of alumina supports and catalysts

The present work shows that the introduction of 0.25–1.25 wt% lanthanum to the composition of aluminum hydroxide at the stage of its hydrothermal synthesis allows increasing the content of the pseudoboehmite phase in the product up to 95 wt% and, as a consequence, reduces the content of the “amorphous” component. Lanthanum uniformly distributes over the surface of aluminum hydroxide as isolated cations with a surface density of 10–15 cations per 10 nm 2 . During plasticizing of lanthanum-modified pseudoboehmite followed by granulation and heat treatment, the formation of the oxide form of La is not observed, and the cations retain their isolated state. The specific surface area of La-modified alumina increases by 18–26 m 2 /g compared to the unmodified sample, while the pore volume remains the same and the average pore diameter slightly reduces. It was found that when the content of La in pseudoboehmite was 1 wt%, the temperature of reaching a residual sulfur content of 10 ppm in the hydrotreated diesel fuel was 5 °C lower comparing to the unmodified sample. • The effect of La addition at the stage of pseudoboehmite preparation was studied. • La promotes the formation of pseudoboehmite phase. • La is present as isolated cations on the surface of pseudoboehmite and alumina. • Catalyst with 1 wt% La shows the highest HDS and HDN activity.

A novel sulfur‐emission free route for preparing ultrafine MoSi2 powder by silicothermic reduction of MoS2

AbstractThe extraction of metal from sulfide mineral is usually accompanied by the emission of sulfur‐containing gas (e.g., SO2), which will cause serious pollution to the environment. In this work, a sulfur‐emission free route for preparing ultrafine molybdenum disilicide (MoSi2) powder by silicothermic reduction of MoS2 with the desulfurization agent of lime was proposed. The internal MoS2‐Si mixture is wrapped in an external desulfurization layer composed of lime. After the reaction is completed, the prepared MoSi2 can be easily separated from the desulfurization layer by using a non‐chemical method. In addition, when the reaction temperature is higher than 1000°C, almost all S in MoS2 is transformed to sulfur‐containing gas SiS, which can be fully captured by lime to generate CaS, Si, and CaSiO3. For the raw material with a MoS2:Si molar ratio of 1:4, after reacting at 1000, 1100, and 1200°C for 2 h, the average grain sizes of the obtained MoSi2 powder are approximately 100, 300, and 800 nm, respectively. Moreover, when the reaction time is prolonged from 2 to 6 h at 1000°C, the average grain size of the acquired MoSi2 powder is about 200 nm, and the residual sulfur content is about 0.12%. This work provides a new insight to extract metals or metal compounds from sulfide ores without releasing sulfur‐containing gas.

Study on the molybdenum electro-extraction from MoS2 in the molten salt

In this study, the electrochemical behavior of MoS2 in NaCl-KCl eutectic system was revealed by transient electrochemical techniques, using a homemade Mo metallic cavity electrode (MCE). In order to investigate the difference between MoS2 and molybdenum free ions in the molten salt, a metallic molybdenum electrode was electro-dissolved into the electrolyte in the form of molybdenum ions. The valence of molybdenum free ions was estimated to be in form of Mo6+ through the XPS analysis. The results of the electrochemical tests show that the reduction steps for MoS2 in NaCl-KCl salt was two and the corresponding reduction potentials were −0.37 V and −0.65 V (vs. Pt), respectively. A three-step reduction was found while investigating molybdenum free ions and the corresponding reduction potentials were 0.15 V, −0.40 V and −0.54 V (vs. Pt), respectively. The results of electrochemical impedance spectroscopy (EIS) analysis on the MoS2 pellet show a decreasing resistance with the increasing of potential. Moreover, potentiostatic electrolysis processes under different potentials were also carried out. Na2Mo3S4 was found to be the intermediate product during the reduction of MoS2 and Mo powder with residual sulfur content of 372 ppm was obtained as the cathode product after the electrolysis under 2.60 V for 20 h. At the same time, elemental sulfur was collected as the anodic product with a self-design condense apparatus.

HYDROPROCESSING OF PETROLEUM FRACTIONS OVER MODIFIED ALUMINIUM OXIDE CATALYSTS

The hydro processing of gasoline and diesel oil fractions over aluminum-nickel-molybdenum catalysts modified by additives HY, ZSM-5, phosphorus and rare earth elements were studied. At the hydro processing of straight-run gasoline over NiO-MoO3- Ce2О3-Р2О5–ZSM(30%)-Al2O3 the content of isoalkanes increases in comparison with the initial from 26.3 to 35.7- 38.3% at 320-400оС. The octane number of refined gasoline at 400оС is 83.7 (RON) and 69.7 (MON). The sulfur content decreases from 0.037% (initial gasoline) to 0.0022%. At hydro processing of straight-run gasoline over NiO-MoO3-La2О3-Р2О5-ZSM-Al2O3 in the range of 320–400 oC the content of isoalkanes is 30.7- 44.3%. The octane number of refined gasoline at 400oC is maximum and is equal to 91.8 (RON) and 72.4 (MON). Under these conditions the sulfur content decreases from 0.0092% to 0.0028%. The optimal conditions for the hydro processing of straight-run gasoline were revealed: T=400˚С, V=2 h-1, Р = 4.0MPa. The catalyst NiO-MoO3-La2О3-Р2О5-ZSM-HY-Al2O3 has the highest hydro desulfurizing activity, the residual sulfur content at 400oС is 0.0012%. The catalyst NiO-MoO3-La2О3-Р2О5-ZSM-Al2O3 has the highest hydro desulfurizing activity. At hydro processing of straight-run diesel fraction on this catalyst under optimal conditions the sulfur content decreases from 0.6400 % to 0.0740 % and during hydro processing of a straight-run diesel fraction with a higher sulfur content 0.8042% - up to 0.053%, which, apparently, is associated with the presence in the feedstock of various types of organosulfur compounds. The lowest pour point and cloud point under optimal conditions reaches minus 39.6oС and minus 30.5oС respectively. Thus, developed modified zeolite-containing catalysts for the hydro processing of gasoline and diesel fractions carry out hydro processing, hydro isomerization and hydrogenation in one stage. The developed catalysts make possible to obtain high-octane low-sulfur gasoline and low-solidification low-sulfur diesel fuel.

Three-phase trickle-bed reactor model for industrial hydrotreating processes: CFD and experimental verification

Catalytic hydrotreating (HDT) is a process used to remove impurities from refinery streams, reacting a given feed with hydrogen at high temperature and pressure in a trickle-bed reactor. In order to optimize the operation of such reactors, one needs information about the detailed performance of the reactor. However, mathematical models of such reactors have not received due attention in last decades. Therefore, this work aimed at revisiting a plug flow HDT model to predict the performance of industrial diesel hydrotreating reactor, which considers most of the HDT reactions, gas-liquid and liquid-solid mass transfer, as well as the influence of catalyst deactivation and quenches injection on model predictions. A fourteen pseudo-component reactional network was proposed and successfully used. Computational fluid dynamics (CFD) predictions verified the plug flow behavior of the industrial HDT reactor. Both the CFD and plug flow models were verified using real process plant data, inspecting residual sulfur content and temperature profiles, with maximum relative error of 14%. Pressure and species concentration profiles as well as the effect of inlet pressure and temperature on final sulfur content were predicted and discussed. Catalyst deactivation is an important factor for accurate prediction of industrial HDT over time of campaign.

Influence of Desulfurization with Fe2O3 on the Reduction of Nickel Converter Slag.

Generally in the nickel converter slag, metals are mainly in the form of sulfides, which are difficult to separate from slag. Although metal oxides in the slag, such as NiO, CoO, and Cu2O, are easily reduced into metal using carbon, the presence of sulfur inhibits the reduction reaction. In this study, the addition of Fe2O3 to nickel converter slag produced desulfurized slag, which enhanced the carbothermal reduction process. Increasing the desulfurization rate promoted the conversion of sulfides into oxides in slag, which significantly increased the activity of NiO, Cu2O, and Fe2O3. However, the residual sulfur content had no significant effect on the activity of FeO and CoO, due to the high initial FeO content and cobalt existing mainly in the form of oxides. The optimum addition of Fe2O3 was 15.0 g per 100 g nickel slag, while the desulfurization ratio was 36.84% and the rates of nikel, cobalt and copper recovery were 95.33%, 77.73%, and 73.83%, respectively.

Titanium-supported W-containing PEO layers enriched with Mn or Zn in oxidative desulfurization and the zwitterionic liquid effect

Titanium-supported oxide layers of W, W + Zn and W + Mn, formed by plasma electrolytic oxidation, were established to catalyze the peroxide oxidation of thiophene. The most active compositions based on Zn-W-containing PEO layers were also tested in the oxidation of a number of organosulfur compounds and diesel fuel desulfurization. Preliminary covering the samples by zwitterionic liquid (ZIL) made it possible to achieve residual sulfur content as low as 6 ppm. The change in the morphology and composition of samples with and without ZIL was studied during catalytic tests. It was found that ZIL reduces the etching of the sample surfaces when interacting with the reaction medium.

Ce-, Zr-containing oxide layers formed by plasma electrolytic oxidation on titanium as catalysts for oxidative desulfurization

Mixed cerium-zirconum-titanum oxide layers: CeOx + TiO2, CeOx + ZrO2 + TiO2, ZrO2 + TiO2 - on titanium were formed by plasma electrolytic oxidation technique in the electrolytes with different ratio of Ce(SO4)3: Zr(SO4)2 and investigated by the complex of physical-chemical methods. Their activity was studied in the peroxide oxidation of sulfur compounds (thiophene, thioanizole and dibenzothiophene) and the desulfurization of diesel fuel. Element and phase composition of the PEO-coated samples affect their catalytic activity. ZrO2 + TiO2 + CeOx systems with the largest content of zirconium showed the highest catalytic activity in oil desulfurization. Their catalytic activity correlates with the presence of the double oxides ZrTiO4 and Ti2ZrO6 in the coating composition. The decrease in the activity of catalysts when they are used in consecutive cycles can be accounted for by the etching of the coatings in the area of the pores. This drawback one can overcome by the addition of an ionic liquid namely 4-(3′-ethylimidazolium)-butanesulfonate, which increases not only the activity, but also the stability of the catalysts. Under these conditions, the structure and activity of the catalyst did not change significantly over several reaction cycles. The combination of PEO treatment and deposition of the ionic liquid allowed one not only to oxidize model substrates, but also carry out the desulfurization of diesel fuel to a residual sulfur content of less than 10 ppm.

Influence of technological parameters and hydrogen-containing gas consumption on the efficiency of middle distillates hydrodesulphurization process

This paper presents the results of a study of the influence of process parameters (contact time, temperature and pressure) and hydrogen-containing gas consumption on the efficiency of catalytic hydrotreating of middle distillate fractions, performed using a mathematical model of the process. It was found that with the increase in the contact time of the raw material with the catalyst, the concentration of sulfides decreases more rapidly than the concentrations of benzothiophenes and dibenzothiophenes. The degree of conversion of sulfides, benzothiophenes and dibenzothiophenes increases with the process temperature in the range from 350 to 425 °C by 39.9; 37.5 and 19.4%, respectively. The greatest degree of desulfurization is achieved by simultaneous increase in pressure and temperature. Thus, at a temperature of 430 °C, an increase in pressure from 2.0 to 4.0 MPa leads to a decrease in the residual sulfur content from 230 to 13.5 ppm. With an increase in the consumption of hydrogen-containing gas from 42,000 to 50,000 m3/h, the efficiency of the hydrotreating process of the middle distillate fractions increases (the residual content of total sulfur in the hydrotreating product decreases from 55.9 to 24.8 ppm).

Optimization of oxidative desulfurization of gas condensate via response surface methodology approach

In the present research, modeling and optimization of a new method of oxidative desulfurization (ODS) of sour gas condensate has been done. In the ODS process, combination of H2SO4, HNO3, and NO2 as oxidizing agents at varying concentrations followed by extraction, was applied. A response surface methodology (RSM) was deployed for the experimental design, model development, and testing the validity of the model using Design-Expert® software.Moreover, investigation of the main effects as well as the combined effects of the process parameters on the response was also carried out. For the first time in a gas-liquid ODS system, a mixing-assisted oxidative desulfurization (MAOD) approach was considered by applying a shear mixer. The value greater than 0.9 for R2 of the sulfur removal data confirmed that the quadratic equation properly fitted the experimental data. Optimization results predicted that the implementation of the process at 0.593, 0.682, and 0.264 mol of H2SO4, HNO3, and NO2, respectively, for a sample of 1500 gr gas condensate, would result in the minimum residual sulfur content of 100.9 ppmw (95.61% sulfur removal) while the actual value of sulfur removal at the predicted optimized conditions was determined as 102 ppmw (95.56% sulfur removal). With respect to the obtained results, the developed model was in good agreement with the experimental results.

Magnetic supported ionic liquid catalysts with tunable pore volume for enhanced deep oxidative desulfurization

Magnetic core-shell structure microspheres with tunable pore volumes were synthesized and used to immobilize a polyoxometalate-based ionic liquid for oxidative desulfurization of diesel fuel. The as-prepared catalysts were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and nitrogen adsorption–desorption. The results showed that the small catalyst had a large pore volume and the large catalyst had a small pore volume, while their BET surface areas and pore sizes were almost the same. Compared with the large catalyst, the small catalyst showed better catalytic activity, probably due to the promotion of its large pore volume. Under the optimal reaction conditions, the removal of 4,6-dimethyldibenzothiophene could reach 95.4% with a residual sulfur content of 9.2 mg kg−1. After the reaction, the catalyst could be separated by a magnetic field and recycled at least 7 times with little decrease in desulfurization efficiency.

Effect of residual sulfur content on the degradation behavior of cellulose acetate

ABSTRACTFour unplasticized, commercially available cellulose acetate (CA) powders were artificially aged for up to 30 weeks in a humid oven at 70°C and 50% relative humidity (RH) to see if higher levels of residual sulfate groups (−OSO2OH)− attached to the cellulose backbone affected degradation. Qualitative x-ray fluorescence (XRF) of unaged powders showed that three contained the same amount of sulfur while the fourth exhibited more. Three powders were manufactured recently whereas the fourth was produced in the 1970s. Powders were aged in lidded borosilicate glass bottles to impede evaporation of acids generated during artificial aging. A water reservoir was enclosed within each bottle to help maintain humidity. Changes to the level of acidity and sample weight were characterized at various time points. All samples emitted acid vapor with aging yet the powder with higher residual sulfate content emitted the most. Similarly, with aging, only the powder with higher level of sulfur content showed a weight loss. No unique behavior was observed from the powder that had naturally aged for forty years before being artificially aged.

Study on reduction of MoS2 powders with activated carbon to produce Mo2C under vacuum conditions

A method of preparing Mo2C via vacuum carbothermic reduction of MoS2 in the temperature range of 1350–1550°C was proposed. The effects of MoS2-to-C molar ratio (α, α = 1:1, 1:1.5, and 1:2.5) and reaction temperature (1350 to 1550°C) on the reaction were studied in detail. The phase transition, morphological evolution, and residual sulfur content of the products were analyzed by X-ray diffraction, field-emission scanning electron microscopy, and carbon–sulfur analysis, respectively. The results showed that the complete decomposition of MoS2 under vacuum is difficult, whereas activated carbon can react with MoS2 under vacuum to generate Mo2C. Meanwhile, higher temperatures and the addition of more carbon accelerated the rate of carbothermic reduction reaction and further decreased the residual sulfur content. From the experimental results, the optimum molar ratio α was concluded to be 1:1.5.

Study on the preparation of molybdenum silicides by the silicothermic reduction of MoS2

In this paper, a novel process about the silicothermic reduction of molybdenum disulfide was proposed to prepare molybdenum silicides. This new method has a short process, which is beneficial for energy saving, environmental protection and cost reduction relative to the traditional methods by using pure molybdenum and silicon as the raw materials. It was found that the phase compositions and microstructures of products were greatly influenced by the molar ratio of Si to MoS2 and temperature. From the experimental results, it was concluded that MoSi2, Mo5Si3 and Mo3Si can be prepared when the temperature was above 1100 °C, 1300 °C and 1500 °C, and the Si/MoS2 molar ratio was 4, 2.6 and 7/3, respectively. When the Si/MoS2 molar ratio was less than 4 and the temperature was below 1100 °C, only one Mo-Si compound (MoSi2) was generated; while above 1200 °C, the excessive MoS2 could react with MoSi2 to generate Mo5Si3, but Mo5Si3 can't react with excessive MoS2 below 1300 °C; until above 1400 °C, Mo5Si3 and MoS2 can react to generate Mo3Si. However, even at 1600 °C, excessive MoS2 couldn't react with Mo3Si but can be decomposed. Besides molybdenum silicides, other products SiS or SiS2 can also be generated. SiS could escape from sample at 1100 °C in the form of gas while SiS2 couldn't. Both the increases of temperature and molar ratio of Si to MoSi2 were beneficial for the decrease of the residual sulfur content in the final products. From the experimental results, it was found that as increasing the temperature or the molar ratio of Si to MoS2 from 7/3 to 4, the grain size of products increased and the sintering phenomenon among grains was more and more obvious.

Catalyst for selective hydrotreating of catalytic cracking gasoline without preliminary fractionation

A new CoMo catalyst for selective hydrotreating of FCC gasoline has been developed; the catalyst is intended for the production of hydrotreated gasoline with up to 10 ppm of sulfur and with a research octane number decreased by less than 1.0. The new catalyst allows hydrotreating of FCC gasoline without its preliminary separation into the light and heavy fractions. The hydrotreating conditions were as follows: hourly space velocity 2.2 h–1, temperature 270°C, pressure 2.5 MPa, H2/feed = 150 m3/m3. The high degree of hydrodesulfurization at minimum decrease in the octane number is achieved due to the high activity of the developed catalyst in hydrodesulfurization of the sulfur-containing components of the feedstock and conversion of reactive high-octane olefins of FCC gasoline into less reactive derivatives with high octane numbers. The catalyst is a CoMoS phase deposited on a support containing amorphous aluminosilicate and γ-Al2O3. The method for the preparation of the catalyst is adapted to the equipment of Russian plants and feedstocks. The parameters of hydrotreating using this catalyst ensure the hydrotreating of FCC gasoline to a residual sulfur content of less than 10 ppm with minimum redesign of the equipment currently available at Russian refineries.

Reactivation of an industrial batch of CoMo/Al2O3 catalyst for the deep hydrotreatment of oil fractions

The results from industrial tests of technology developed earlier for the reactivation of CoMo/Al2O3 catalyst for the deep hydrotreating of diesel fuel, including the oxidative regeneration of the catalyst with subsequent treatment using organic complexing agents, are presented. Samples of the catalyst, fresh and at different stages of its reactivation, are investigated using a set of analytical and physicochemical methods. The chemical composition, textural characteristics, mechanical strength, structure of the active sulfide component (TEM, XPS) are determined. Catalytic tests are performed that include lifetime tests (360 h) in the hydrotreatment of a straight-run diesel fraction. The restoration of the physicochemical and catalytic properties is observed for a sample subjected to oxidative regeneration with subsequent treatment using organic complexing agents. An industrial batch of deep hydrotreatment catalyst reactivated by this technology is loaded into an L-24-6 industrial plant facility and ensures stable purification of straight-run diesel fuel containing up to 10% of light catalytic cracking gas oil to a residual sulfur content of less than 10 ppm. Comparison of the obtained results and data on the industrial operation of fresh catalysts shows that the technology developed by the Institute of Catalysis and PAO Gazprom Neft ensures almost complete restoration of the properties of the deactivated catalysts.

Synthesis, characterization and application of some non-halogen ionic liquids as green solvents for deep desulfurization of diesel oil

Some non-halogen ionic liquids (1-n-butyl-3-methylimidazolium hydrosulphates ([BMIM][[HSO4]), 1-n-butyl-3-methylimidazolium acetate ([BMIM][CH3COO]), 1-n-butyl-3-methylimidazolium dibutyl phosphate ([BMIM][DBP]), 1-n-octyl-3-methylimidazolium hydrosulphates ([OMIM][HSO4]), and 1-n-octyl-3-methylimidazolium acetate ([OMIM][CH3COO])) were synthesized, characterized, and used as solvents for extraction of sulfur compounds in model oils. All investigated ionic liquids show high desulfurization performance from the model oils. The influence of factors such as the structures of ionic liquid anions and cations, and the structure of sulfur compounds on the deep desulfurization was investigated. Some ionic liquids with high, mild and low desulfurization ability ([OMIM][CH3COO], [BMIM][DBP], and [BMIM][[HSO4], respectively) were used as solvents to extract sulfur compounds in diesel oil. The residual sulfur contents in diesel oil meet Euro III and Euro IV standards after five or six extraction cycles corresponding to a desulfurization efficiency of approximately 97%. The combination of oxidation reagents and [BMIM][HSO4] or [BPy][HSO4] increases the desulfurization efficiency. The used ionic liquids were recovered by re-extraction of sulfur compounds and oxidation products of DBT from ionic liquid phase to ethyl acetate or cyclohexane. The formation of sulfones and sulfoxides during oxidative desulfurization was confirmed by FT-IR spectra of ethyl acetate that was used to recover ionic liquids. The slight decrease in desulfurization efficiency of recovered ionic liquids shows their high potential of reusability. Used ethyl acetate and cyclohexane were recovered by distillation and sulfur compounds can be used for other purposes. The extraction process was performed at room temperatures and under normal pressures; no high hydrogen pressure was needed.

Catalytic oxidative desulfurization of BT and DBT from n -octane using cyclohexanone peroxide and catalyst of molybdenum supported on 4A molecular sieve

Abstract In this paper, the performance of catalytic oxidative desulfurization (ODS) was studied using catalyst MoO 3 /4A which was prepared by depositing molybdenum on 4A molecular sieve, a microporous material. Dibenzothiophene (DBT) and benzothiophene (BT) were selected as the target compounds, and oil-soluble cyclohexanone peroxide (CYHPO) as an oxidant. The effects of relevant parameters on ODS including molybdenum loading, reaction temperature, reaction time, the molar ratio of CYHPO/DBT and the weight of catalyst MoO 3 /4A were investigated, and the oxidation mechanisms as well as the kinetics were also examined individually. The catalytic oxidative removal of DBT and the residual sulfur content reached 99.0% and 5 ppmw, respectively, at an optimal catalytic condition of Mo loading of 6 wt.%, molar ratio of CYHPO/DBT of 2.5 and volume mass ratio of model gasoline to catalyst MoO 3 /4A of 100 at 373 K over 30 min. The optimal design of experiments using Box–Behnken method was employed to evaluate the effects of individual process variables such as, reaction temperature, reaction time and molar ratio of CYHPO/DBT and their optimum values were found to be 340 K, 38 min and 3.8, respectively, to achieve a conversion of 100%. The catalyst could be reused for 4 times before the total DBT content of treated model gasoline was higher than 10 ppmw, and the activity of the desulfurization system was above 95% after regenerating for 9 times. The catalytic oxidation of DBT and BT fitted the pseudo-first order kinetic model pretty well. The catalyst MoO 3 /4A was characterized by the scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectrum (XPS), and the data showed that a thin layer of active components was covered on the catalyst surface which helped to explain the satisfactory catalytic performance.