Catalytic oxidation desulfurization(CODS)technology has shown great promise for diesel desulfurization by virtue of its low cost,mild reaction conditions,and superior desulfurization performance.Herein,a series of FeM...Catalytic oxidation desulfurization(CODS)technology has shown great promise for diesel desulfurization by virtue of its low cost,mild reaction conditions,and superior desulfurization performance.Herein,a series of FeMoO_(x)/LaTiO_(y)-z samples with diverse Fe/Mo ratios were prepared via a facile citric acid-assisted method.The impact of Fe incorporation on the dispersion and surface elemental states of Mo species,as well as oxygen species content of the synthesized FeMoO_(x)/LaTiO_(y)-z catalysts were systematically characterized using TEM,BET,UV-vis DRS,XPS,XANES,and reaction kinetics,and their CODS performances were examined for 4,6-DMDBT removal.Experimental results demonstrated that Fe/Mo ratio significantly affected the Ti−O bond strength,surface dispersion and electronic structure of Mo O_(2)species on FeMoO_(x)/LaTiO_(y)-z catalysts.FeMoO_(x)/LaTiO_(y)-2 catalyst showed outstanding cycling durability and the best CODS performance with almost 100%removal of 4,6-DMDBT from model oil within 75 min due to its proper MoO3 dispersion,optimal redox property,and the most oxygen vacancy concentration.Nevertheless,further enhancing Fe content led to the increased dispersion of Mo species,while the decrease active Mo species as well as the increase of steric effect for 4,6-DMDBT accessing to the catalytic reactive sites considerably increase the apparent activation energy of FeMoO_(x)/LaTiO_(y)-z(z>2)catalysts during the CODS process,thereby seriously suppressing their CODS performances.Moreover,Radical trapping experiments reveal that the·,generated by the activation of O_(2)at the active sites,catalytic oxidized 4,6-DMDBT to the product of 4,6-DMDBTO_(2),thereby enabling both deep desulfurization and recovery of high-value 4,6-DMDBTO_(2).These findings offer an alternative strategy to achieve ultra deep desulfurization as well as separate and recover high economic value sulfone substances from diesel.展开更多
The chemical composition of seawater affects the desulfurization of chalcopyrite in flotation.In this study,desulfurization experiments of chalcopyrite were conducted in both deionized(DI)water and seawater.The result...The chemical composition of seawater affects the desulfurization of chalcopyrite in flotation.In this study,desulfurization experiments of chalcopyrite were conducted in both deionized(DI)water and seawater.The results showed that,the copper grade of the concentrate obtained from seawater flotation decreased to 24.30%,compared to 24.60%in DI water.Concurrently,the recovery of chalcopyrite decreased from 51.39%to 38.67%,while the selectivity index(SI)also had a reduction from 2.006 to 1.798.The incorporation of ethylene diamine tetraacetic acid(EDTA),sodium silicate(SS),and sodium hexametaphosphate(SHMP)yielded an enhancement in the SI value,elevating it from 1.798 to 1.897,2.250 and 2.153,separately.It is particularly noteworthy that an excess of EDTA resulted in a SI value of merely 1.831.The mechanism of action was elucidated through analysis of surface charge measurements,X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FT-IR),extended Derjaguin-Landau Verwey-Overbeek(E-DLVO)theory,and density functional theory(DFT)calculations.展开更多
The influence of sulfur content in raw materials on oxidized pellets was studied. The results show that most sulfur exists in the form of elementary sulfur in pyrite cinder, and over 95% sulfur is removed in producing...The influence of sulfur content in raw materials on oxidized pellets was studied. The results show that most sulfur exists in the form of elementary sulfur in pyrite cinder, and over 95% sulfur is removed in producing pyrite cinder oxidized pellets. The compressive strength of fired pellets drops from 3 186 N to 2 405 N when the ratio of pyrite cinder increases from 40% to 70% under the conditions of preheating at 900℃ for 9 min and firing at 1 230 ℃ for 15 min. The porosity and microstructures of fired pellets prove that the higher ratio of pyrite cinder is given, and the more holes and cracks are achieved, leading to the better reducibility index （RI） and reduction swelling index （RSI）, and the lower compressive strength of fired pellets and the worse reduction degradation index （RDI）.展开更多
The absorbent composing of Bayer red mud and water was prepared and applied to removing SO2 from flue gas.Effects of the ratio of liquid to solid(L/S),the absorption temperature,the inlet SO2 concentration,the O2 conc...The absorbent composing of Bayer red mud and water was prepared and applied to removing SO2 from flue gas.Effects of the ratio of liquid to solid(L/S),the absorption temperature,the inlet SO2 concentration,the O2 concentration,SO4^2-and other different components of Bayer red mud on desulfurization were conducted.The mechanism of flue gas desulfurization was also established.The results indicated that L/S was the prominent factor,followed by the inlet SO2 concentration and the temperature was the least among them.The optimum condition was as follows:L/S,the temperature and the SO2 concentration were 20:1,25℃and 1000 mg/m^3,respectively,under the gas flow of 1.5 L/min.The desulfurization efficiency was not significantly influenced when O2 concentration was above 7%.The accumulation of SO4^2-inhibited the desulfurization efficiency.The alkali absorption and metal ions liquid catalytic oxidation were involved in the process,which accounted for 98.61%.展开更多
The massive accumulation of flue gas desulfurization(FGD)gypsum produced in the wet limestone-gypsum flue gas desulfurization process not only encroaches on lands but also causes serious environmental pollution.The pr...The massive accumulation of flue gas desulfurization(FGD)gypsum produced in the wet limestone-gypsum flue gas desulfurization process not only encroaches on lands but also causes serious environmental pollution.The preparation ofα-hemihydrate gypsum(α-HH)is an important way to achieve high-value utilization of FGD gypsum.Although the glycerol-water solution approach can be used to produceα-HH from FGD gypsum under mild conditions,the transition is kinetically unfavorable in the mixed solution.Here,an easy pretreatment was used to activate FGD gypsum by calcination and hydration to readily complete the transition.The pretreatment deteriorated the crystallinity of FGD gypsum and caused it to form small irregular flaky crystals,which dramatically increased the specific surface area.Additionally,most of the organics adsorbed onto FGD gypsum surfaces were removed after pretreatment.The poor crystallinity,increased specific surface area,and elimination of organics adsorbed onto crystal surfaces effectively improved the conversion activity of FGD gypsum,thereby promoting dihydrate gypsum(DH)dissolution andα-HH nucleation.Overall,the phase transition of FGD gypsum toα-HH is facilitated.展开更多
Several methods of deep desulfurization in alumina production process were studied, and the costs of these methods were compared. It is found that most of the S2- in sodium aluminate solution can be removed by adding ...Several methods of deep desulfurization in alumina production process were studied, and the costs of these methods were compared. It is found that most of the S2- in sodium aluminate solution can be removed by adding sodium nitrate or hydrogen peroxide in digestion process, and in this way the effect of S2- on alumina product quality is eliminated. However, the removal efficiency of 2?32OS in sodium aluminate solution is very low by this method. Both S2- and 2?32OS in sodium aluminate solution can be removed completely by wet oxidation method in digestion process. The cost of desulfurization by wet oxidation is lower than by adding sodium nitrate or hydrogen peroxide. The results of this research reveal that wet oxidation is an economical and feasible method for the removal of sulfur in alumina production process to improve alumina quality, and provide valuable guidelines for alumina production by high-sulfur bauxite.展开更多
To recover metal from copper slags,a new process involving two steps of oxidative desulfurization followed by smelting reduction was proposed in which one hazardous waste(waste cathode carbon)was used to treat another...To recover metal from copper slags,a new process involving two steps of oxidative desulfurization followed by smelting reduction was proposed in which one hazardous waste(waste cathode carbon)was used to treat another(copper slags).The waste cathode carbon is used not only as a reducing agent but also as a fluxing agent to decrease slag melting point.Upon holding for 60 min in air atmosphere first and then smelting with 14.4 wt%waste cathode carbon and 25 wt%CaO for 180 min in high purity Ar atmosphere at 1450℃,the recovery rates of Cu and Fe reach 95.89%and 94.64%,respectively,and meanwhile greater than 90%of the fluoride from waste cathode carbon is transferred into the final slag as CaF_(2) and Ca_(2)Si_(2)F_(2)O_(7),which makes the content of soluble F in the slag meet the national emission standard.Besides,the sulphur content in the obtained Fe-Cu alloy is low to 0.03 wt%.展开更多
Desulfurization experiments of CuO, γ-Al2O3 and CuO/γ-Al2O3 were made in simulated flue gas by means of thermogravimetric analysis. It is found that reaction activities of CuO supported on γ-Al2O3 could be highly i...Desulfurization experiments of CuO, γ-Al2O3 and CuO/γ-Al2O3 were made in simulated flue gas by means of thermogravimetric analysis. It is found that reaction activities of CuO supported on γ-Al2O3 could be highly improved. Desulfurization kinetics of CuO/γ-Al2O3 was studied in the temperature range of 250 °C-400 °C and SO2 concentration of 0.1%-0.9%. The experimental data were tested and compared with kinetics models of volume reaction model(VRM), grain size model(GSM), random pore model(RPM) and pore-blocking model(PBM). Correlation analysis shows that VRM and RPM models do not fit experimental data well. GSM contradicts with the changes in the physical and chemical properties of Cu O/γ-Al2O3 as the desulfurization proceeds. It is found that PBM is consistent with the change of pore structure of CuO/γ-Al2O3 sorbent during desulfurization process and predicts the conversion-time curves of the sorbent well. Meanwhile, kinetics parameters are obtained and discussed.展开更多
Fuel desulfurization is an appealing topic for the chemical industry since severe environmental regulations regarding SO_2 emissions have been legislated in many countries. In order to reduce the amount of sulfur-cont...Fuel desulfurization is an appealing topic for the chemical industry since severe environmental regulations regarding SO_2 emissions have been legislated in many countries. In order to reduce the amount of sulfur-containing compounds in fuels,responsible for high SO_x emission levels,a green chemistry approach is compulsory. In this paper,vanadium salen and salophen complexes were used in the oxidation of a model aromatic sulfide,such as dibenzothiophene( DBT),in the presence of H_2O_2 as green oxidant. The oxidative process was successfully coupled with the extraction of the oxidized compounds by ionic liquids. The system resulted highly selective for sulfide oxidation,showing poor reactivity toward the oxidation of alkenes and allowing a significant reduction of S content in a model benzine. To note,the use of microwave in place of standard heating allowed to obtain 98% of DBT oxidation and almost complete sulfur extraction in the model fuel in 1000 s. For these reasons,this system was considered an easy,rapid and clean process to achieve fuel desulfurization.展开更多
Recently, organosulfur removal from liquid petroleum fuels is very significant aspect of environment protecting and fuel cell requests. Therefore, improved approaches to remove sulfur are still essential. In the prese...Recently, organosulfur removal from liquid petroleum fuels is very significant aspect of environment protecting and fuel cell requests. Therefore, improved approaches to remove sulfur are still essential. In the present work, a simple catalytic oxidative desulfurization (CODS) system for Iraqi gasoil fraction has been successfully developed using CuO-ZnO nanocomposites as catalysts, and H 2O 2 as oxidant under microwave irradiation. The main reaction parameters influencing sulfur conversion including microwave power, irradiation time, catalyst dosage and H 2O 2 to gasoil volume ratio have been investigated. The CuO-ZnO nanocomposites was synthesized with different weight ratios and characterized by XRD, FE-SEM, AFM and BET surface area methods. The results reveal that, high sulfur conversion (93%) has been achieved under suitable conditions of microwave CODS as follows: microwave power of 540 W, irradiation time of 15 min, catalyst dosage of 8 g/L (0.4 g), and H 2O 2 ∶gasoil volume ratio of 0.3. The catalyst reusability shows that the synthesized catalyst can be reused five times without an important loss in its activity.展开更多
By orthodox experiment, the main influence factors of desulfurization by sulfolobas of pH value, temperature, coal slurry concentration and coal granularity are studied in detail and the optimal experimental condition...By orthodox experiment, the main influence factors of desulfurization by sulfolobas of pH value, temperature, coal slurry concentration and coal granularity are studied in detail and the optimal experimental conditions were also obtained. The experimental results demonstrate that sulfolobas being kind of linking-heat, acidophilic and self-supported bacterium with double characters can effectively remove inorganic and organic sulfur in coal. The superlatively desulfurization rate is up to 48.57% total sulfur and 41.71% inorganic sulfur within 10 d and its desulfurization rate can be greatly affected by the four factors above mentioned. Therefore, the optimum conditions of desulfurization are obtained by comprehensive experiment and they are as following: pH value 3, temperature 70℃, coal slurry concentration 10% and coal granularity 150 μm, respectively. Moreover, the repetition experimental results confirm that the desulfurization by sulfolobas is steady.展开更多
Titania coating of multi wall carbon nano tube(MWCNT) was carried out by sol-gel method in order to improve its photo catalytic properties.The effect of MWCNT/TiO_2 mass to volume ratio on adsorption ability,reaction ...Titania coating of multi wall carbon nano tube(MWCNT) was carried out by sol-gel method in order to improve its photo catalytic properties.The effect of MWCNT/TiO_2 mass to volume ratio on adsorption ability,reaction rate and photo-catalytic removal efficiency of dibenzothiophene(DBT) from n-hexane solution was investigated using a 9 W UV lamp.The results show that the addition of nanotubes improves the photo-catalytic properties of TiO_2 by two factors;however,the DBT removal rate versus MWCNT content is found to follow a bimodal pattern.Two factors are observed to affect the removal rate of DBT and produce two optimum values for MWCNT content.First,large quantities of MWCNTs prevent light absorption by the solution and decrease removal efficiency.By contrast,a low dosage of MWCNT causes recombination of the electron holes,which also decreases the DBT removal rate.The optimum MWCNT contents in the composite are found to be 0.25 g and 0.75 g MWCNT per 80 m L of sol.展开更多
The recovery of iron from iron sinking slag and lead smelter slag was investigated by desulfurization-reduction bath smelting. The effects of lead smelter slag(LSS) to iron sinking slag(ISS) mass ratio and temperature...The recovery of iron from iron sinking slag and lead smelter slag was investigated by desulfurization-reduction bath smelting. The effects of lead smelter slag(LSS) to iron sinking slag(ISS) mass ratio and temperature were investigated in desulfurization experiments. The X-ray diffraction(XRD) and X-ray fluorescence(XRF) analyses show that the optimum conditions are LSS:ISS of 3:7 and temperature of 1350°C. The composition of desulfurization products is mainly Zn Fe2O4, and the desulfurization rate of 99.66% is obtained under optimum conditions. The thermogravimetric(TG) and differential scanning calorimeter(DSC) analyses demonstrate that reductant is necessary for decomposition and reduction of zinc ferrite in desulfurization product. The effects of reductant, temperature and feeding modes on iron enrichment were investigated in reduction experiments. The scanning electron microscope(SEM) and energy dispersive spectrometer(EDS) determination show that the iron content of reduction product is up to 99.36% under optimum conditions of coke as reductant, reduction temperature of 1450°C and the feeding mode of premixing.展开更多
In this research,1-butyl-pyridinium tetrafluoroborate([C4Py][BF4]-)was prepared by ion exchange method and was characterized by1H-NM R,13C-NM R,and FT-IR techniques.The synthesized ionic liquid w as used for removal o...In this research,1-butyl-pyridinium tetrafluoroborate([C4Py][BF4]-)was prepared by ion exchange method and was characterized by1H-NM R,13C-NM R,and FT-IR techniques.The synthesized ionic liquid w as used for removal of dibenzothiophene as a typical organosulfur pollutant from organic medium.The effect of different parameters on the extraction efficiency w as studied and optimized.At the optimized conditions,97.68%of dibenzothiophene w as extracted from 1 000 mg/L n-hexane solution.The extraction efficiency obtained in this w ork w as higher than the previous reported values.The desulfurization reaction w as kinetically follow ed the second order mechanism.The ionic liquid w as reusable and after four regeneration cycles 97%of its original extraction efficiency w as retained.展开更多
The influence of coal desulfurization by fungus was experimentally studied.The results suggest that fungus can effectively remove inorganic and organic sulfur in coal,and main influences of desulfurization by fungus o...The influence of coal desulfurization by fungus was experimentally studied.The results suggest that fungus can effectively remove inorganic and organic sulfur in coal,and main influences of desulfurization by fungus of pH value,temperature,coal slurry concentration and coal granularity were studied by orthodox experiment and the optimal experimental conditions are′as follows:pH value 6,temperature 45℃,coal slurry concentration 10%and coal granularity 100μm.Under above conditions,fungus car remove up to 44.96%total sulfur and 54.87%inorganic sulfur within two days,and their desulfurization rates will increase along with time.Compared with sulfolobas,desulphurization by fungus is steady and more effective,and has advantage of high speed.展开更多
基金supported by the Natural Science Foundation of Guangdong Province(2024A1515010908,2025A1515011103)Opening Project of Hubei Key Laboratory of Plasma Chemistry and Advanced Materials(2024P11)+2 种基金Postdoctoral Fellowship Program of CPSF(GZC20233104)National Natural Science Foundation of China(22202087)Opening Project of Hubei Key Laboratory of Biomass Fibers and Eco-Dyeing&Finishing(STRZ202418)。
文摘Catalytic oxidation desulfurization(CODS)technology has shown great promise for diesel desulfurization by virtue of its low cost,mild reaction conditions,and superior desulfurization performance.Herein,a series of FeMoO_(x)/LaTiO_(y)-z samples with diverse Fe/Mo ratios were prepared via a facile citric acid-assisted method.The impact of Fe incorporation on the dispersion and surface elemental states of Mo species,as well as oxygen species content of the synthesized FeMoO_(x)/LaTiO_(y)-z catalysts were systematically characterized using TEM,BET,UV-vis DRS,XPS,XANES,and reaction kinetics,and their CODS performances were examined for 4,6-DMDBT removal.Experimental results demonstrated that Fe/Mo ratio significantly affected the Ti−O bond strength,surface dispersion and electronic structure of Mo O_(2)species on FeMoO_(x)/LaTiO_(y)-z catalysts.FeMoO_(x)/LaTiO_(y)-2 catalyst showed outstanding cycling durability and the best CODS performance with almost 100%removal of 4,6-DMDBT from model oil within 75 min due to its proper MoO3 dispersion,optimal redox property,and the most oxygen vacancy concentration.Nevertheless,further enhancing Fe content led to the increased dispersion of Mo species,while the decrease active Mo species as well as the increase of steric effect for 4,6-DMDBT accessing to the catalytic reactive sites considerably increase the apparent activation energy of FeMoO_(x)/LaTiO_(y)-z(z>2)catalysts during the CODS process,thereby seriously suppressing their CODS performances.Moreover,Radical trapping experiments reveal that the·,generated by the activation of O_(2)at the active sites,catalytic oxidized 4,6-DMDBT to the product of 4,6-DMDBTO_(2),thereby enabling both deep desulfurization and recovery of high-value 4,6-DMDBTO_(2).These findings offer an alternative strategy to achieve ultra deep desulfurization as well as separate and recover high economic value sulfone substances from diesel.
基金Project(52174239)supported by the National Natural Science Foundation of ChinaProject(2021YFC2902400)supported by the National Key R&D Program of China。
文摘The chemical composition of seawater affects the desulfurization of chalcopyrite in flotation.In this study,desulfurization experiments of chalcopyrite were conducted in both deionized(DI)water and seawater.The results showed that,the copper grade of the concentrate obtained from seawater flotation decreased to 24.30%,compared to 24.60%in DI water.Concurrently,the recovery of chalcopyrite decreased from 51.39%to 38.67%,while the selectivity index(SI)also had a reduction from 2.006 to 1.798.The incorporation of ethylene diamine tetraacetic acid(EDTA),sodium silicate(SS),and sodium hexametaphosphate(SHMP)yielded an enhancement in the SI value,elevating it from 1.798 to 1.897,2.250 and 2.153,separately.It is particularly noteworthy that an excess of EDTA resulted in a SI value of merely 1.831.The mechanism of action was elucidated through analysis of surface charge measurements,X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FT-IR),extended Derjaguin-Landau Verwey-Overbeek(E-DLVO)theory,and density functional theory(DFT)calculations.
基金Project(2007k02) supported by the Technology Fund of the Land and Resources Department of Hunan Province, China
文摘The influence of sulfur content in raw materials on oxidized pellets was studied. The results show that most sulfur exists in the form of elementary sulfur in pyrite cinder, and over 95% sulfur is removed in producing pyrite cinder oxidized pellets. The compressive strength of fired pellets drops from 3 186 N to 2 405 N when the ratio of pyrite cinder increases from 40% to 70% under the conditions of preheating at 900℃ for 9 min and firing at 1 230 ℃ for 15 min. The porosity and microstructures of fired pellets prove that the higher ratio of pyrite cinder is given, and the more holes and cracks are achieved, leading to the better reducibility index （RI） and reduction swelling index （RSI）, and the lower compressive strength of fired pellets and the worse reduction degradation index （RDI）.
基金Project(2017YFC0210500)supported by the National Key Technology R&D Program of ChinaProject(2017ACA092)supported by the Major Projects of Technical Innovation in Hubei Province,China
文摘The absorbent composing of Bayer red mud and water was prepared and applied to removing SO2 from flue gas.Effects of the ratio of liquid to solid(L/S),the absorption temperature,the inlet SO2 concentration,the O2 concentration,SO4^2-and other different components of Bayer red mud on desulfurization were conducted.The mechanism of flue gas desulfurization was also established.The results indicated that L/S was the prominent factor,followed by the inlet SO2 concentration and the temperature was the least among them.The optimum condition was as follows:L/S,the temperature and the SO2 concentration were 20:1,25℃and 1000 mg/m^3,respectively,under the gas flow of 1.5 L/min.The desulfurization efficiency was not significantly influenced when O2 concentration was above 7%.The accumulation of SO4^2-inhibited the desulfurization efficiency.The alkali absorption and metal ions liquid catalytic oxidation were involved in the process,which accounted for 98.61%.
基金Projects(51904104,51974117,51804114)supported by the National Natural Science Foundation of ChinaProjects(2018YFC1901601,2018YFC1901602,2018YFC1901605)supported by the National Key Scientific Research Project of China+1 种基金Project(2015CX005)supported by the Innovation Driven Plan of Central South University,ChinaProject(18B226)supported by the Excellent Youth Project of Hunan Education Department,China
文摘The massive accumulation of flue gas desulfurization(FGD)gypsum produced in the wet limestone-gypsum flue gas desulfurization process not only encroaches on lands but also causes serious environmental pollution.The preparation ofα-hemihydrate gypsum(α-HH)is an important way to achieve high-value utilization of FGD gypsum.Although the glycerol-water solution approach can be used to produceα-HH from FGD gypsum under mild conditions,the transition is kinetically unfavorable in the mixed solution.Here,an easy pretreatment was used to activate FGD gypsum by calcination and hydration to readily complete the transition.The pretreatment deteriorated the crystallinity of FGD gypsum and caused it to form small irregular flaky crystals,which dramatically increased the specific surface area.Additionally,most of the organics adsorbed onto FGD gypsum surfaces were removed after pretreatment.The poor crystallinity,increased specific surface area,and elimination of organics adsorbed onto crystal surfaces effectively improved the conversion activity of FGD gypsum,thereby promoting dihydrate gypsum(DH)dissolution andα-HH nucleation.Overall,the phase transition of FGD gypsum toα-HH is facilitated.
基金Project(51404121)supported by the National Natural Science Foundation of ChinaProject(KKSY201452041)supported by Yunnan Provincal Personnel Training Funds for Kunming University of Science and Technology,China
文摘Several methods of deep desulfurization in alumina production process were studied, and the costs of these methods were compared. It is found that most of the S2- in sodium aluminate solution can be removed by adding sodium nitrate or hydrogen peroxide in digestion process, and in this way the effect of S2- on alumina product quality is eliminated. However, the removal efficiency of 2?32OS in sodium aluminate solution is very low by this method. Both S2- and 2?32OS in sodium aluminate solution can be removed completely by wet oxidation method in digestion process. The cost of desulfurization by wet oxidation is lower than by adding sodium nitrate or hydrogen peroxide. The results of this research reveal that wet oxidation is an economical and feasible method for the removal of sulfur in alumina production process to improve alumina quality, and provide valuable guidelines for alumina production by high-sulfur bauxite.
基金Project(U1602272)supported by the National Natural Science Foundation of China。
文摘To recover metal from copper slags,a new process involving two steps of oxidative desulfurization followed by smelting reduction was proposed in which one hazardous waste(waste cathode carbon)was used to treat another(copper slags).The waste cathode carbon is used not only as a reducing agent but also as a fluxing agent to decrease slag melting point.Upon holding for 60 min in air atmosphere first and then smelting with 14.4 wt%waste cathode carbon and 25 wt%CaO for 180 min in high purity Ar atmosphere at 1450℃,the recovery rates of Cu and Fe reach 95.89%and 94.64%,respectively,and meanwhile greater than 90%of the fluoride from waste cathode carbon is transferred into the final slag as CaF_(2) and Ca_(2)Si_(2)F_(2)O_(7),which makes the content of soluble F in the slag meet the national emission standard.Besides,the sulphur content in the obtained Fe-Cu alloy is low to 0.03 wt%.
基金Projects(51264023,51364020,U1202271)supported by the National Natural Science Foundation of ChinaProject(IRT1250)supported by the Program for Innovative Research Team in University of Ministry of Education of ChinaProject(2014HA003)supported by the Yunnan Province Science and Technology Talents Program,China
文摘Desulfurization experiments of CuO, γ-Al2O3 and CuO/γ-Al2O3 were made in simulated flue gas by means of thermogravimetric analysis. It is found that reaction activities of CuO supported on γ-Al2O3 could be highly improved. Desulfurization kinetics of CuO/γ-Al2O3 was studied in the temperature range of 250 °C-400 °C and SO2 concentration of 0.1%-0.9%. The experimental data were tested and compared with kinetics models of volume reaction model(VRM), grain size model(GSM), random pore model(RPM) and pore-blocking model(PBM). Correlation analysis shows that VRM and RPM models do not fit experimental data well. GSM contradicts with the changes in the physical and chemical properties of Cu O/γ-Al2O3 as the desulfurization proceeds. It is found that PBM is consistent with the change of pore structure of CuO/γ-Al2O3 sorbent during desulfurization process and predicts the conversion-time curves of the sorbent well. Meanwhile, kinetics parameters are obtained and discussed.
基金The project was supported by the University of Rome“Tor Vergata”,SUSCARE project.
文摘Fuel desulfurization is an appealing topic for the chemical industry since severe environmental regulations regarding SO_2 emissions have been legislated in many countries. In order to reduce the amount of sulfur-containing compounds in fuels,responsible for high SO_x emission levels,a green chemistry approach is compulsory. In this paper,vanadium salen and salophen complexes were used in the oxidation of a model aromatic sulfide,such as dibenzothiophene( DBT),in the presence of H_2O_2 as green oxidant. The oxidative process was successfully coupled with the extraction of the oxidized compounds by ionic liquids. The system resulted highly selective for sulfide oxidation,showing poor reactivity toward the oxidation of alkenes and allowing a significant reduction of S content in a model benzine. To note,the use of microwave in place of standard heating allowed to obtain 98% of DBT oxidation and almost complete sulfur extraction in the model fuel in 1000 s. For these reasons,this system was considered an easy,rapid and clean process to achieve fuel desulfurization.
文摘Recently, organosulfur removal from liquid petroleum fuels is very significant aspect of environment protecting and fuel cell requests. Therefore, improved approaches to remove sulfur are still essential. In the present work, a simple catalytic oxidative desulfurization (CODS) system for Iraqi gasoil fraction has been successfully developed using CuO-ZnO nanocomposites as catalysts, and H 2O 2 as oxidant under microwave irradiation. The main reaction parameters influencing sulfur conversion including microwave power, irradiation time, catalyst dosage and H 2O 2 to gasoil volume ratio have been investigated. The CuO-ZnO nanocomposites was synthesized with different weight ratios and characterized by XRD, FE-SEM, AFM and BET surface area methods. The results reveal that, high sulfur conversion (93%) has been achieved under suitable conditions of microwave CODS as follows: microwave power of 540 W, irradiation time of 15 min, catalyst dosage of 8 g/L (0.4 g), and H 2O 2 ∶gasoil volume ratio of 0.3. The catalyst reusability shows that the synthesized catalyst can be reused five times without an important loss in its activity.
文摘By orthodox experiment, the main influence factors of desulfurization by sulfolobas of pH value, temperature, coal slurry concentration and coal granularity are studied in detail and the optimal experimental conditions were also obtained. The experimental results demonstrate that sulfolobas being kind of linking-heat, acidophilic and self-supported bacterium with double characters can effectively remove inorganic and organic sulfur in coal. The superlatively desulfurization rate is up to 48.57% total sulfur and 41.71% inorganic sulfur within 10 d and its desulfurization rate can be greatly affected by the four factors above mentioned. Therefore, the optimum conditions of desulfurization are obtained by comprehensive experiment and they are as following: pH value 3, temperature 70℃, coal slurry concentration 10% and coal granularity 150 μm, respectively. Moreover, the repetition experimental results confirm that the desulfurization by sulfolobas is steady.
文摘Titania coating of multi wall carbon nano tube(MWCNT) was carried out by sol-gel method in order to improve its photo catalytic properties.The effect of MWCNT/TiO_2 mass to volume ratio on adsorption ability,reaction rate and photo-catalytic removal efficiency of dibenzothiophene(DBT) from n-hexane solution was investigated using a 9 W UV lamp.The results show that the addition of nanotubes improves the photo-catalytic properties of TiO_2 by two factors;however,the DBT removal rate versus MWCNT content is found to follow a bimodal pattern.Two factors are observed to affect the removal rate of DBT and produce two optimum values for MWCNT content.First,large quantities of MWCNTs prevent light absorption by the solution and decrease removal efficiency.By contrast,a low dosage of MWCNT causes recombination of the electron holes,which also decreases the DBT removal rate.The optimum MWCNT contents in the composite are found to be 0.25 g and 0.75 g MWCNT per 80 m L of sol.
基金Project(2011AA061003)supported by the National High Technology Research and Development Program of China
文摘The recovery of iron from iron sinking slag and lead smelter slag was investigated by desulfurization-reduction bath smelting. The effects of lead smelter slag(LSS) to iron sinking slag(ISS) mass ratio and temperature were investigated in desulfurization experiments. The X-ray diffraction(XRD) and X-ray fluorescence(XRF) analyses show that the optimum conditions are LSS:ISS of 3:7 and temperature of 1350°C. The composition of desulfurization products is mainly Zn Fe2O4, and the desulfurization rate of 99.66% is obtained under optimum conditions. The thermogravimetric(TG) and differential scanning calorimeter(DSC) analyses demonstrate that reductant is necessary for decomposition and reduction of zinc ferrite in desulfurization product. The effects of reductant, temperature and feeding modes on iron enrichment were investigated in reduction experiments. The scanning electron microscope(SEM) and energy dispersive spectrometer(EDS) determination show that the iron content of reduction product is up to 99.36% under optimum conditions of coke as reductant, reduction temperature of 1450°C and the feeding mode of premixing.
文摘In this research,1-butyl-pyridinium tetrafluoroborate([C4Py][BF4]-)was prepared by ion exchange method and was characterized by1H-NM R,13C-NM R,and FT-IR techniques.The synthesized ionic liquid w as used for removal of dibenzothiophene as a typical organosulfur pollutant from organic medium.The effect of different parameters on the extraction efficiency w as studied and optimized.At the optimized conditions,97.68%of dibenzothiophene w as extracted from 1 000 mg/L n-hexane solution.The extraction efficiency obtained in this w ork w as higher than the previous reported values.The desulfurization reaction w as kinetically follow ed the second order mechanism.The ionic liquid w as reusable and after four regeneration cycles 97%of its original extraction efficiency w as retained.
基金Project(2002AA649220)supported by Hi-tech Research and Development Programeproject(1667)supported by thePostdoctoral Science Foundation of Central South University
文摘The influence of coal desulfurization by fungus was experimentally studied.The results suggest that fungus can effectively remove inorganic and organic sulfur in coal,and main influences of desulfurization by fungus of pH value,temperature,coal slurry concentration and coal granularity were studied by orthodox experiment and the optimal experimental conditions are′as follows:pH value 6,temperature 45℃,coal slurry concentration 10%and coal granularity 100μm.Under above conditions,fungus car remove up to 44.96%total sulfur and 54.87%inorganic sulfur within two days,and their desulfurization rates will increase along with time.Compared with sulfolobas,desulphurization by fungus is steady and more effective,and has advantage of high speed.
