Industrial-use VOx-based catalysts usually have a higher active temperature window (>250-300℃),which becomes a“bottleneck”for the practical application of PCDD/Fs catalytic degradation technology.In this work,VO...Industrial-use VOx-based catalysts usually have a higher active temperature window (>250-300℃),which becomes a“bottleneck”for the practical application of PCDD/Fs catalytic degradation technology.In this work,VO_(x)-FeO_(x)/TiO_(2) catalyst prepared via mechanochemically method was investigated for the catalytic removal of PCDD/Fs.The removal efficiency of 1,2-DCBz,pure PCDD/Fs gas generated in the lab,PCDD/Fs from actual fue gas,long-term were studied,and the degradation mechanism was explored using FTIR and TOFMS.The degradation efficiency of 1,2-DCBz and PCDD/Fs on VO_(x)-FeO_(x)/TiO_(2) were higher than that of VO_(x)/TiO_(2)catalyst,and the optimal FeOx addition ratio was 3 wt.%.The characterization results show that the addition of FeOx can effectively improve the pore structure,surface acidity,and VOx dispersion of the catalyst,thus contributing to increasing the V^(5+)content and surface-active oxygen,which is conducive to the improvement of adsorption and redox performance of the catalyst.Under the actual MSWI (municipal solid waste incineration)fue gas,the PCDD/Fs removal efficiency over VTi-3Fe-MC maintained long-term stability,higher than 85%for 240 min.This result was not significantly reduced compared with the data obtained in the laboratory.According to the analysis results of intermediate products by FTIR and GC-TOFMS,it can be inferred that the epoxidation fracture of benzene ring is the rate-limiting step of dioxin catalytic degradation reaction.This work gives an in-depth view into the PCDD/Fs removal over VO_(x)-FeO_(x)/TiO_(2) catalysts and could provide guidelines for the rational design of reliable catalysts for industrial applications.展开更多
The Mn-Ce-Fe mixed oxide(MCFe)was prepared by co-precipitation and the catalytic performance was tested by using 1,2-dichlorobenzene(1,2-DCB)and furan as model molecules of PCDD/F.The effect of O_(2)concentration,SO_(...The Mn-Ce-Fe mixed oxide(MCFe)was prepared by co-precipitation and the catalytic performance was tested by using 1,2-dichlorobenzene(1,2-DCB)and furan as model molecules of PCDD/F.The effect of O_(2)concentration,SO_(2) and NO on the catalytic activity was studied.At 270℃,the MCFe oxide catalyst presents significant simultaneous removal efficiency of 75.25%and 100%for 1,2-DCB and furan,respectively.Brunauer-Emmett-Teller(BET)method(BET),X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR),H_2-temperature programmed reduction(H_(2)-TPR),NH_(3)-temperature programmed desorption(NH_3-TPD)and O_(2)-TPD were used to characterize the catalysts before and after the reaction.Competition tests suggest that the oxidation behavior of furan occurred prior to that of 1,2-DCB.According to the intermediate products detected by gas chromatography-mass spectrometry(GC-MS),the by-products include chlorinated hydrocarbons,long-chain hydrocarbons,ketone,etc.Possible catalytic oxidation reaction paths are proposed.展开更多
The removal of polychlorinated dibenzo-p-dioxins and dibenzo-furans(PCDD/Fs)and dust from municipal solid waste incineration flue gas within a single device can improve operational efficiency and reduce costs.In this ...The removal of polychlorinated dibenzo-p-dioxins and dibenzo-furans(PCDD/Fs)and dust from municipal solid waste incineration flue gas within a single device can improve operational efficiency and reduce costs.In this study,a catalytic filter was developed using ultrasonic immersion and polytetrafluoroethylene(PTFE)membrane fixation,combining a blank PTFE and VO_(x)/TiO_(2) catalyst.Chlorobenzene(CB)and furan were selected as model molecules for PCDD/Fs.A series of VO_(x)/TiO_(2) catalysts were synthesized through a mechanochemical method,with different types and ratios of components tested.Among these catalysts,the VWMoTi catalyst demonstrated the highest CB removal efficiency(RE),reaching over 85%at temperatures below 200℃.The VWMoTi catalyst was impregnated into a PTFE filter for the catalytic combustion of CB and furan.The process parameters,including the catalyst loading and catalyst particle size,were analyzed.The physicochemical properties of the catalytic filter were extensively characterized.The catalytic activity of CB,furan,and dust removal performance of the catalytic filters was investigated.At 240℃,the RE values of CB and furan were 70.82%and 100%,respectively,whereas the RE of dust reached 99.99%.展开更多
A novel selective catalytic reduction(SCR)catalyst with high catalytic activity on chloroaromatic organics at lower temperatures(160-180℃)is critical for municipal solid waste incineration(MSWI)plants.This study prep...A novel selective catalytic reduction(SCR)catalyst with high catalytic activity on chloroaromatic organics at lower temperatures(160-180℃)is critical for municipal solid waste incineration(MSWI)plants.This study prepares a series of honeycomb-type VO_(x)/TiO_(2) catalysts and finally develops a new low-temperature catalyst with high catalytic activity in eliminating chloroaromatic organics.Based on the conversion efficiency(CE)of 1,2-dichlorobenzene(1,2-DCB)and CO_(2) selectivity,the optimal VO_(x) content of 4.06%(in weight)in VO_(x)/TiO_(2) catalyst is first confirmed.By modifying CeO_(x) and WO_(x),a novel honeycomb-type catalyst of VO_(x)-CeO_(x)-WO_(x)/TiO_(2) achieves the highest CE(93.1%-93.6%)and CO_(2) selectivity(40.9%-60.7%)at 150-200℃.It was found that the CeO_(x) and WO_(x) can improve the catalytic activity by enriching the surface content of V and O,increasing the proportion of V5+and Osurf,enlarging the supply source of reactive oxygen species and their storage capacity,and accelerating the redox cycle of VO_(x),CeO_(x),WO_(x),and reactive oxygen species.This study can guide the development of monolithic low-temperature catalysts with high catalytic activity in eliminating chloroaromatic organics in MSWI flue gas.展开更多
During the period of COVID-19,the medical waste disposal capacity is seriously inadequate.The main technical process of the municipal solid waste incineration system is the same as that of the medical waste incinerati...During the period of COVID-19,the medical waste disposal capacity is seriously inadequate.The main technical process of the municipal solid waste incineration system is the same as that of the medical waste incineration system.Under the conditions of optimizing the technological process,improving the supporting facilities,and controlling the co-processing ratio,the municipal solid waste incinerator(grate furnace)co-processing medical waste is feasible.Some suggested guidelines for emergency treatment of medical waste from COVID-19 have been provided by China.展开更多
In this study,Mn-based bimetallic oxide catalysts were synthesized via the solvothermal method.Different metals(Ce,Co and Fe)exhibited a great impact on the physicochemical properties of catalysts,resulting in differe...In this study,Mn-based bimetallic oxide catalysts were synthesized via the solvothermal method.Different metals(Ce,Co and Fe)exhibited a great impact on the physicochemical properties of catalysts,resulting in different catalytic activities for the simultaneous removal of 1,2-dichlorobenzene(1,2-DCB)and furan,as a model of polychlorinated dibenzodioxins and dibenzo-furans(PCDD/Fs).Fe–MnOx presented the best catalytic activity,with a removal efficiency of 62%for 1,2-DCB and 100%for furan at 240℃.Several analytical techniques were employed,namely,Brunauer–Emmett–Teller(BET),X-ray diffraction(XRD),scanning electron microscope(SEM),X-ray photoelectron spectroscopy(XPS),H_(2)temperature-programmed reduction(H_(2)-TPR),and ammonia temperature programmed desorption(NH_(3)-TPD).Compared with pure MnOx catalysts,Fe–MnOx shows a higher specific surface area of 117.9 m^(2)/g.SEM observations showed flower-like nanosheet structures for Fe–MnOx.XPS analysis indicated that Mn^(4+)/Mn^(3+)and active oxygen play the key roles in the catalytic oxidation of 1,2-DCB and furan.The catalytic activity,selectivity and stability of Mn-based bimetallic oxide catalysts for the oxidation of 1,2-DCB and furan were tested.Competition exists between 1,2-DCB and furan such that the adsorption of furan occurs prior to 1,2-DCB.展开更多
Correctionto:Waste Disposal&Sustainable Energy(2022)4:105-116 https://doi.0rg/10.1007/s42768-022-00096-1 The section‘Conflict of Interest'has been amended:'Jianhua Yan is the Editor-in-Chief of Waste Disp...Correctionto:Waste Disposal&Sustainable Energy(2022)4:105-116 https://doi.0rg/10.1007/s42768-022-00096-1 The section‘Conflict of Interest'has been amended:'Jianhua Yan is the Editor-in-Chief of Waste Disposal&Sustainable Energy.'The revised‘Conflict of Interest'is as follows:Jianhua Yan is the Editor-in-Chief of Waste Disposal&Sustainable Energy.The authors declare that they haveno conflictofinterest.展开更多
Domestic waste in China is mainly collected as a combination of different types of materials.The components are variable and complex,with very different combustion characteristics making it difficult to optimize the b...Domestic waste in China is mainly collected as a combination of different types of materials.The components are variable and complex,with very different combustion characteristics making it difficult to optimize the burning to reduce pollution.There are still some controversies about the accuracy of using carbon monoxide(CO)emission to characterize waste incineration performance.Here,we investigated the relationship between waste classification,incineration conditions and dioxin emission and concluded that the concentration of CO in flue gas could not be used as the only criterion of combustion efficiency and safety.Considering the close relationship between the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)and products of incomplete combustion,the relatively low concentrations of CO are not a reliable indicator that an incinerator equipped with an activated carbon injection system and fabric filter could achieve the national standards for PCDD/F emission.The goal,therefore,is not only to lower the emission of PCDD/Fs and other pollutants through clas-sifying the waste components at the source,but also to reduce the need for the treatment of incinerated waste to protect the environment and to increase the power generation efficiency of municipal solid waste incineration(MSWI)plants.As the demand for waste disposal continues to rapidly increase,the need for a safe waste incineration system with dioxin emission controls makes the classification of waste an indispensable part of future MSWI systems.展开更多
This study was carried out in a full-scale(50 t/d)rotary kiln incinerator to explore the removal characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)by different units of air pollution contr...This study was carried out in a full-scale(50 t/d)rotary kiln incinerator to explore the removal characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)by different units of air pollution control devices(APCDs),and special interest was focused on the“memory effect”phenomenon of PCDD/Fs in the wet scrubber(WS),which usually caused an undesirable rise in PCDD/F emission concentrations.The general removal efficiency of PCDD/Fs by APCDs was 99.4%(from 14.11 at exhaust heat boiler(EHB)outlet to 0.09 ng I-TEQ/Nm^(3)at stack)under medical waste(MW)incineration condition,and 99.2%(from 19.91 to 0.16 ng I-TEQ/Nm^(3))under hazardous waste(HW)incineration condition.The PCDD/F concentrations in flue gas decreased along the APCDs except for WS,in which the“memory effect”was observed.In detail,WS largely increased the I-TEQ concentration of gas-phase PCDD/Fs from 0.047 to 0.188 ng I-TEQ/Nm^(3)in the flue gas,and the concentration of particulate-phase PCDD/Fs increased from 0.003 to 0.030 ng I-TEQ/Nm^(3).In addition,this study found that phase migration promoted the accumulation of PCDD/Fs in scrubbing water,and the flow entrainment phenomenon played a great role in causing the“memory effect”.The PCDD/F concentrations of fly ash collected from cyclone and fabric filter(FF)were as high as 4.23 and 6.99 ng I-TEQ/g,respectively,which had exceeded the national landfill limitation(3 ng I-TEQ/g)in China.The system balance calculations revealed that APCDs promoted the migration of PCDD/Fs from the gas-phase to the particulate-phase,which caused fly ash to be the main carrier of PCDD/Fs and led to excessive emissions.The results of this study can contribute to the optimized design of combustion conditions and system cleaning for controlling PCDD/F emissions from rotary kiln incinerators.展开更多
基金supported by the Natural Science Foundation of Zhejiang Province (No. LY21E060007)the National Natural Science Foundation of China (No. 52006191)。
文摘Industrial-use VOx-based catalysts usually have a higher active temperature window (>250-300℃),which becomes a“bottleneck”for the practical application of PCDD/Fs catalytic degradation technology.In this work,VO_(x)-FeO_(x)/TiO_(2) catalyst prepared via mechanochemically method was investigated for the catalytic removal of PCDD/Fs.The removal efficiency of 1,2-DCBz,pure PCDD/Fs gas generated in the lab,PCDD/Fs from actual fue gas,long-term were studied,and the degradation mechanism was explored using FTIR and TOFMS.The degradation efficiency of 1,2-DCBz and PCDD/Fs on VO_(x)-FeO_(x)/TiO_(2) were higher than that of VO_(x)/TiO_(2)catalyst,and the optimal FeOx addition ratio was 3 wt.%.The characterization results show that the addition of FeOx can effectively improve the pore structure,surface acidity,and VOx dispersion of the catalyst,thus contributing to increasing the V^(5+)content and surface-active oxygen,which is conducive to the improvement of adsorption and redox performance of the catalyst.Under the actual MSWI (municipal solid waste incineration)fue gas,the PCDD/Fs removal efficiency over VTi-3Fe-MC maintained long-term stability,higher than 85%for 240 min.This result was not significantly reduced compared with the data obtained in the laboratory.According to the analysis results of intermediate products by FTIR and GC-TOFMS,it can be inferred that the epoxidation fracture of benzene ring is the rate-limiting step of dioxin catalytic degradation reaction.This work gives an in-depth view into the PCDD/Fs removal over VO_(x)-FeO_(x)/TiO_(2) catalysts and could provide guidelines for the rational design of reliable catalysts for industrial applications.
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(LQ23E060002)the National Natural Science Foundation of China(51976192)。
文摘The Mn-Ce-Fe mixed oxide(MCFe)was prepared by co-precipitation and the catalytic performance was tested by using 1,2-dichlorobenzene(1,2-DCB)and furan as model molecules of PCDD/F.The effect of O_(2)concentration,SO_(2) and NO on the catalytic activity was studied.At 270℃,the MCFe oxide catalyst presents significant simultaneous removal efficiency of 75.25%and 100%for 1,2-DCB and furan,respectively.Brunauer-Emmett-Teller(BET)method(BET),X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR),H_2-temperature programmed reduction(H_(2)-TPR),NH_(3)-temperature programmed desorption(NH_3-TPD)and O_(2)-TPD were used to characterize the catalysts before and after the reaction.Competition tests suggest that the oxidation behavior of furan occurred prior to that of 1,2-DCB.According to the intermediate products detected by gas chromatography-mass spectrometry(GC-MS),the by-products include chlorinated hydrocarbons,long-chain hydrocarbons,ketone,etc.Possible catalytic oxidation reaction paths are proposed.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LQ23E060002)the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2023C03125).
文摘The removal of polychlorinated dibenzo-p-dioxins and dibenzo-furans(PCDD/Fs)and dust from municipal solid waste incineration flue gas within a single device can improve operational efficiency and reduce costs.In this study,a catalytic filter was developed using ultrasonic immersion and polytetrafluoroethylene(PTFE)membrane fixation,combining a blank PTFE and VO_(x)/TiO_(2) catalyst.Chlorobenzene(CB)and furan were selected as model molecules for PCDD/Fs.A series of VO_(x)/TiO_(2) catalysts were synthesized through a mechanochemical method,with different types and ratios of components tested.Among these catalysts,the VWMoTi catalyst demonstrated the highest CB removal efficiency(RE),reaching over 85%at temperatures below 200℃.The VWMoTi catalyst was impregnated into a PTFE filter for the catalytic combustion of CB and furan.The process parameters,including the catalyst loading and catalyst particle size,were analyzed.The physicochemical properties of the catalytic filter were extensively characterized.The catalytic activity of CB,furan,and dust removal performance of the catalytic filters was investigated.At 240℃,the RE values of CB and furan were 70.82%and 100%,respectively,whereas the RE of dust reached 99.99%.
基金supported by the National Key Research and Development Program of China (No.2020YFC1910100).
文摘A novel selective catalytic reduction(SCR)catalyst with high catalytic activity on chloroaromatic organics at lower temperatures(160-180℃)is critical for municipal solid waste incineration(MSWI)plants.This study prepares a series of honeycomb-type VO_(x)/TiO_(2) catalysts and finally develops a new low-temperature catalyst with high catalytic activity in eliminating chloroaromatic organics.Based on the conversion efficiency(CE)of 1,2-dichlorobenzene(1,2-DCB)and CO_(2) selectivity,the optimal VO_(x) content of 4.06%(in weight)in VO_(x)/TiO_(2) catalyst is first confirmed.By modifying CeO_(x) and WO_(x),a novel honeycomb-type catalyst of VO_(x)-CeO_(x)-WO_(x)/TiO_(2) achieves the highest CE(93.1%-93.6%)and CO_(2) selectivity(40.9%-60.7%)at 150-200℃.It was found that the CeO_(x) and WO_(x) can improve the catalytic activity by enriching the surface content of V and O,increasing the proportion of V5+and Osurf,enlarging the supply source of reactive oxygen species and their storage capacity,and accelerating the redox cycle of VO_(x),CeO_(x),WO_(x),and reactive oxygen species.This study can guide the development of monolithic low-temperature catalysts with high catalytic activity in eliminating chloroaromatic organics in MSWI flue gas.
基金supported by the National Natural Science Foundation of China(51621005)the Fundamental Research Funds for the Central Universities(2019FZA4010).
文摘During the period of COVID-19,the medical waste disposal capacity is seriously inadequate.The main technical process of the municipal solid waste incineration system is the same as that of the medical waste incineration system.Under the conditions of optimizing the technological process,improving the supporting facilities,and controlling the co-processing ratio,the municipal solid waste incinerator(grate furnace)co-processing medical waste is feasible.Some suggested guidelines for emergency treatment of medical waste from COVID-19 have been provided by China.
基金supported by the Natural Science Foundation of Zhejiang Province(No.LY21E060007)the National Natural Science Foundation of China(No.51976192,No.52006191).
文摘In this study,Mn-based bimetallic oxide catalysts were synthesized via the solvothermal method.Different metals(Ce,Co and Fe)exhibited a great impact on the physicochemical properties of catalysts,resulting in different catalytic activities for the simultaneous removal of 1,2-dichlorobenzene(1,2-DCB)and furan,as a model of polychlorinated dibenzodioxins and dibenzo-furans(PCDD/Fs).Fe–MnOx presented the best catalytic activity,with a removal efficiency of 62%for 1,2-DCB and 100%for furan at 240℃.Several analytical techniques were employed,namely,Brunauer–Emmett–Teller(BET),X-ray diffraction(XRD),scanning electron microscope(SEM),X-ray photoelectron spectroscopy(XPS),H_(2)temperature-programmed reduction(H_(2)-TPR),and ammonia temperature programmed desorption(NH_(3)-TPD).Compared with pure MnOx catalysts,Fe–MnOx shows a higher specific surface area of 117.9 m^(2)/g.SEM observations showed flower-like nanosheet structures for Fe–MnOx.XPS analysis indicated that Mn^(4+)/Mn^(3+)and active oxygen play the key roles in the catalytic oxidation of 1,2-DCB and furan.The catalytic activity,selectivity and stability of Mn-based bimetallic oxide catalysts for the oxidation of 1,2-DCB and furan were tested.Competition exists between 1,2-DCB and furan such that the adsorption of furan occurs prior to 1,2-DCB.
文摘Correctionto:Waste Disposal&Sustainable Energy(2022)4:105-116 https://doi.0rg/10.1007/s42768-022-00096-1 The section‘Conflict of Interest'has been amended:'Jianhua Yan is the Editor-in-Chief of Waste Disposal&Sustainable Energy.'The revised‘Conflict of Interest'is as follows:Jianhua Yan is the Editor-in-Chief of Waste Disposal&Sustainable Energy.The authors declare that they haveno conflictofinterest.
基金the National Natural Science Foundation of China(51621005)the National Key Research and Development Program of China(2017YFC0703100).
文摘Domestic waste in China is mainly collected as a combination of different types of materials.The components are variable and complex,with very different combustion characteristics making it difficult to optimize the burning to reduce pollution.There are still some controversies about the accuracy of using carbon monoxide(CO)emission to characterize waste incineration performance.Here,we investigated the relationship between waste classification,incineration conditions and dioxin emission and concluded that the concentration of CO in flue gas could not be used as the only criterion of combustion efficiency and safety.Considering the close relationship between the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)and products of incomplete combustion,the relatively low concentrations of CO are not a reliable indicator that an incinerator equipped with an activated carbon injection system and fabric filter could achieve the national standards for PCDD/F emission.The goal,therefore,is not only to lower the emission of PCDD/Fs and other pollutants through clas-sifying the waste components at the source,but also to reduce the need for the treatment of incinerated waste to protect the environment and to increase the power generation efficiency of municipal solid waste incineration(MSWI)plants.As the demand for waste disposal continues to rapidly increase,the need for a safe waste incineration system with dioxin emission controls makes the classification of waste an indispensable part of future MSWI systems.
基金supported by the National Key Research and Development Program of China(No.2020YFC1910100).
文摘This study was carried out in a full-scale(50 t/d)rotary kiln incinerator to explore the removal characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)by different units of air pollution control devices(APCDs),and special interest was focused on the“memory effect”phenomenon of PCDD/Fs in the wet scrubber(WS),which usually caused an undesirable rise in PCDD/F emission concentrations.The general removal efficiency of PCDD/Fs by APCDs was 99.4%(from 14.11 at exhaust heat boiler(EHB)outlet to 0.09 ng I-TEQ/Nm^(3)at stack)under medical waste(MW)incineration condition,and 99.2%(from 19.91 to 0.16 ng I-TEQ/Nm^(3))under hazardous waste(HW)incineration condition.The PCDD/F concentrations in flue gas decreased along the APCDs except for WS,in which the“memory effect”was observed.In detail,WS largely increased the I-TEQ concentration of gas-phase PCDD/Fs from 0.047 to 0.188 ng I-TEQ/Nm^(3)in the flue gas,and the concentration of particulate-phase PCDD/Fs increased from 0.003 to 0.030 ng I-TEQ/Nm^(3).In addition,this study found that phase migration promoted the accumulation of PCDD/Fs in scrubbing water,and the flow entrainment phenomenon played a great role in causing the“memory effect”.The PCDD/F concentrations of fly ash collected from cyclone and fabric filter(FF)were as high as 4.23 and 6.99 ng I-TEQ/g,respectively,which had exceeded the national landfill limitation(3 ng I-TEQ/g)in China.The system balance calculations revealed that APCDs promoted the migration of PCDD/Fs from the gas-phase to the particulate-phase,which caused fly ash to be the main carrier of PCDD/Fs and led to excessive emissions.The results of this study can contribute to the optimized design of combustion conditions and system cleaning for controlling PCDD/F emissions from rotary kiln incinerators.
