The humidity effects on the benzene decomposition process were investigated by the dielectric barrier discharge（DBD） plasma reactor.The results showed that the water vapor played an important role in the benzene oxi...The humidity effects on the benzene decomposition process were investigated by the dielectric barrier discharge（DBD） plasma reactor.The results showed that the water vapor played an important role in the benzene oxidation process.It was found that there was an optimum humidity value for the benzene removal efficiency,and at around 60% relative humidity（RH）,the optimum benzene removal efficiency was achieved.At a SIE of 378 J/L,the removal efficiency was 66% at 0% RH,while the removal efficiency reached 75.3% at 60% RH and dropped to 69% at 80% RH.Furthermore,the addition of water inhibited the formation of ozone and NO2 remarkably.Both of the concentrations of ozone and NO2 decreased with increasing of the RH at the same specific input energy.At a SIE of 256 J/L,the concentrations of ozone and NO2 were 5.4 mg/L and 1791 ppm under dry conditions,whereas they were only 3.4 mg/L and 1119 ppm at 63.5%RH,respectively.Finally,the outlet gas after benzene degradation was qualitatively analyzed by FT-IR and GC-MS to determine possible intermediate byproducts.The results suggested that the byproducts in decomposition of benzene primarily consisted of phenol and substitutions of phenol.Based on these byproducts a benzene degradation mechanism was proposed.展开更多
For improving the energy efficiency of plasma volatile organic compounds( VOCs) decomposition, a pulse modulated power is used to drive the dielectric barrier discharge( DBD) plasma to treat benzene. Through the chang...For improving the energy efficiency of plasma volatile organic compounds( VOCs) decomposition, a pulse modulated power is used to drive the dielectric barrier discharge( DBD) plasma to treat benzene. Through the change of pulse duty cycle,the pulse modulation effect on benzene removal energy efficiency was investigated. The results show that pulse modulation can improve the energy yield and reduce the temperature of the chamber wall. There is an optimal duty cycle for achieving the maximum energy yield at a certain discharge voltage. The effect of initial benzene concentration on the decomposition efficiency and carbon selectivity in pulse modulation plasma were studied. The results indicate that the removal efficiency and carbon balance increase with the specific input energy( SIE) and decrease with the concentration. The energy yield increases with increasing initial concentration and achieves maximum around 180 J / L SIE for all initial concentrations.展开更多
In this paper,the formation mechanism of mesoporous CeO_(2) synthesized by thermal decomposition of Ce-MOF and its performance of benzene catalytic combustion,as well as the structure-activity relationship between the...In this paper,the formation mechanism of mesoporous CeO_(2) synthesized by thermal decomposition of Ce-MOF and its performance of benzene catalytic combustion,as well as the structure-activity relationship between them were studied in depth.The self-assembly process and physicochemical properties of CeO_(2) were characterized by thermogravimetry analysis,powder X-ray diffraction,N2 adsorption/desorption,high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy techniques.Characterization results show that Ce-MOF is completely decomposed into pure mesoporous CeO_(2) when the decomposition temperature is higher than 400℃.At this threshold temperature,CeO_(2)(400) has the largest specific surface area and pore volume of 114 m^(2)/g and 0.152 cm^(3)/g,respectively.CeO_(2)(400) exhibits very high catalytic activity for benzene combustion,which can completely catalyze the degradation of benzene at 260℃.Meanwhile,the mesoporous CeO_(2)(400) supported Pt nanocrystalline catalysts were prepared by high temperature solution-phase reduction method.Pt/CeO_(2)(400)can completely degrade benzene at about 200℃ and represents high durability and good waterresistance for benzene combustion during 100 h of continuous reaction.展开更多
Single-stage process of obtaining active carbon by thermal processing of plant raw materials (mixture of different types of wood sawdust), impregnated with the mixture of phosphoric acid, urea and nitric acid salts ha...Single-stage process of obtaining active carbon by thermal processing of plant raw materials (mixture of different types of wood sawdust), impregnated with the mixture of phosphoric acid, urea and nitric acid salts has been developed. Active influence of impregnates on the process of carbonization and formation of carbon residue has been formed. It is established that carbon residue obtained in the interval of heating 20℃-(500℃-700℃), possesses high sorption activity to the vapors of organic compounds and has ion-exchange capacity. It has been showed that the value of carton residue depending on the impregnate used in the wood increases compared to the yield of non-treated initial raw materials by 3.1 times at 600℃ and by 4.2 times at 700℃.展开更多
基金supported by National Natural Science Foundation of China(Nos.11205007 and 11205029)
文摘The humidity effects on the benzene decomposition process were investigated by the dielectric barrier discharge（DBD） plasma reactor.The results showed that the water vapor played an important role in the benzene oxidation process.It was found that there was an optimum humidity value for the benzene removal efficiency,and at around 60% relative humidity（RH）,the optimum benzene removal efficiency was achieved.At a SIE of 378 J/L,the removal efficiency was 66% at 0% RH,while the removal efficiency reached 75.3% at 60% RH and dropped to 69% at 80% RH.Furthermore,the addition of water inhibited the formation of ozone and NO2 remarkably.Both of the concentrations of ozone and NO2 decreased with increasing of the RH at the same specific input energy.At a SIE of 256 J/L,the concentrations of ozone and NO2 were 5.4 mg/L and 1791 ppm under dry conditions,whereas they were only 3.4 mg/L and 1119 ppm at 63.5%RH,respectively.Finally,the outlet gas after benzene degradation was qualitatively analyzed by FT-IR and GC-MS to determine possible intermediate byproducts.The results suggested that the byproducts in decomposition of benzene primarily consisted of phenol and substitutions of phenol.Based on these byproducts a benzene degradation mechanism was proposed.
文摘For improving the energy efficiency of plasma volatile organic compounds( VOCs) decomposition, a pulse modulated power is used to drive the dielectric barrier discharge( DBD) plasma to treat benzene. Through the change of pulse duty cycle,the pulse modulation effect on benzene removal energy efficiency was investigated. The results show that pulse modulation can improve the energy yield and reduce the temperature of the chamber wall. There is an optimal duty cycle for achieving the maximum energy yield at a certain discharge voltage. The effect of initial benzene concentration on the decomposition efficiency and carbon selectivity in pulse modulation plasma were studied. The results indicate that the removal efficiency and carbon balance increase with the specific input energy( SIE) and decrease with the concentration. The energy yield increases with increasing initial concentration and achieves maximum around 180 J / L SIE for all initial concentrations.
基金Project supported by Zhejiang Public Welfare Technology Research Project(LGG19B070003)the Foundation of Science and Technology of the Shaoxing City(2018C10019)the National Natural Science Foundation of China(21577094)。
文摘In this paper,the formation mechanism of mesoporous CeO_(2) synthesized by thermal decomposition of Ce-MOF and its performance of benzene catalytic combustion,as well as the structure-activity relationship between them were studied in depth.The self-assembly process and physicochemical properties of CeO_(2) were characterized by thermogravimetry analysis,powder X-ray diffraction,N2 adsorption/desorption,high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy techniques.Characterization results show that Ce-MOF is completely decomposed into pure mesoporous CeO_(2) when the decomposition temperature is higher than 400℃.At this threshold temperature,CeO_(2)(400) has the largest specific surface area and pore volume of 114 m^(2)/g and 0.152 cm^(3)/g,respectively.CeO_(2)(400) exhibits very high catalytic activity for benzene combustion,which can completely catalyze the degradation of benzene at 260℃.Meanwhile,the mesoporous CeO_(2)(400) supported Pt nanocrystalline catalysts were prepared by high temperature solution-phase reduction method.Pt/CeO_(2)(400)can completely degrade benzene at about 200℃ and represents high durability and good waterresistance for benzene combustion during 100 h of continuous reaction.
文摘Single-stage process of obtaining active carbon by thermal processing of plant raw materials (mixture of different types of wood sawdust), impregnated with the mixture of phosphoric acid, urea and nitric acid salts has been developed. Active influence of impregnates on the process of carbonization and formation of carbon residue has been formed. It is established that carbon residue obtained in the interval of heating 20℃-(500℃-700℃), possesses high sorption activity to the vapors of organic compounds and has ion-exchange capacity. It has been showed that the value of carton residue depending on the impregnate used in the wood increases compared to the yield of non-treated initial raw materials by 3.1 times at 600℃ and by 4.2 times at 700℃.
