For their distinguished global warming potential（GWP100）and long atmosphere lifespan,CF_4,SF_6 and SF_5CF_3were significant in the field of greenhouse gas research.The details of discharging character and the optima...For their distinguished global warming potential（GWP100）and long atmosphere lifespan,CF_4,SF_6 and SF_5CF_3were significant in the field of greenhouse gas research.The details of discharging character and the optimal parameter were discussed by using a Dielectric Barrier Discharge（DBD）reactor to decompose these potent greenhouse gases in this work.The results showed that SF_6 could be decomposed by 92% under the conditions of 5 min resident time and3000 V applied voltage with the partial pressure of 2.0 k Pa,28.2 k Pa,and 1.8 k Pa for SF_6,air and water vapor,respectively.0.4 k Pa CF_4 could be decomposed by 98.2% for 4 min resident time with 30 k Pa Ar added.The decomposition of SF_5CF_3 was much more effective than that of SF_6 and CF_4and moreover,1.3 k Pa SF_5CF_3,discharged with 30 k PaO_2,Ar and air,could not be detected when the resident time was 80 s,40 s,and 120 s,respectively.All the results indicated that DBD was a feasible technique for the abatement of potent greenhouse gases.展开更多
A coaxial dielectric barrier discharge (DBD) reactor was used for plasma-catalytic degradation of tetracycline hydrochloride over a series of Mn/γ-Al2O3 catalysts prepared by the incipient wetness impregnation method...A coaxial dielectric barrier discharge (DBD) reactor was used for plasma-catalytic degradation of tetracycline hydrochloride over a series of Mn/γ-Al2O3 catalysts prepared by the incipient wetness impregnation method.The combination of plasma and the Mn/γ-Al2O3 catalysts significantly enhanced the degradation efficiency of tetracycline hydrochloride compared to the plasma process alone,with the 10% Mn/γ-Al2O3 catalyst exhibiting the best tetracycline hydrochloride degradation efficiency.A maximum degradation efficiency of 99.3% can be achieved after 5 min oxidation and a discharge power of 1.3 W,with only 69.7% by a single plasma process.The highest energy yield of the plasma-catalytic process is 91.7 g kWh-1.Probable reaction mechanisms of the plasma-catalytic removal of tetracycline hydrochloride were also proposed.展开更多
This paper discusses the removal of nitric oxide （NO） with low-temperature selective catalytic reduction driven by a dielectric barrier discharge with ammonia （NH3） as a reductant. We explored the effects of NH3, ...This paper discusses the removal of nitric oxide （NO） with low-temperature selective catalytic reduction driven by a dielectric barrier discharge with ammonia （NH3） as a reductant. We explored the effects of NH3, O2, temperature and water under different applied voltage on NO removal at atmospheric pressure. The results showed that when the gas concentration ration of NH3/NO was 0.23-0.67, the NO removal efficiency and the energy consumption was acceptable. The NO removal efficiency reached 84% under an applied voltage of 7 kV, 400 ppm NO and 90 ppm NH3 at a temperature of 150 ℃. Water vapor had a negative effect because NO formation reactions were strengthened and NH3 was oxidized directly rather than reduced NO molecules. The outlet gas components were observed via Fourier transform infrared spectroscopy for revealing the decomposition process and mechanism.展开更多
In this paper, a study of homogenous dielectric barrier discharge Ar–NHwas made in order to investigate the electrical and the physical characteristics of homogenous discharge at atmospheric pressure. The discharge m...In this paper, a study of homogenous dielectric barrier discharge Ar–NHwas made in order to investigate the electrical and the physical characteristics of homogenous discharge at atmospheric pressure. The discharge model includes the electrical module and the chemical kinetic module. The results obtained by the present model were compared with experimental work. The evolution of the plasmas voltage, the species densities, and the concentration of charged species are analyzed and discussed.展开更多
A wire-mesh catalyst coated by La0.8Sr0.2MnO3 was combined with a dielectric barrier discharge （DBD） reactor for toluene removal at atmospheric pressure. It was found that toluene removal efficiency and carbon dioxi...A wire-mesh catalyst coated by La0.8Sr0.2MnO3 was combined with a dielectric barrier discharge （DBD） reactor for toluene removal at atmospheric pressure. It was found that toluene removal efficiency and carbon dioxide selectivity were enhanced in the catalytic packed-bed reactor. In addition, ozone and nitrogen monoxide from the gas effluent byproducts decreased. This is the first time that ultrasound combined with plasma has been used for toluene removal. A synergistic effect on toluene removal was observed in the plasma-assisted ultrasound system. At the same time, the system increased toluene conversion and reduced ozone emission.展开更多
The performance of dielectric material is a key factor against a long time action in dielectric barrier discharge （DBD） plasma. In this study, the aging of the Al2O3 dielectric material was studied by the Atomic For...The performance of dielectric material is a key factor against a long time action in dielectric barrier discharge （DBD） plasma. In this study, the aging of the Al2O3 dielectric material was studied by the Atomic Force Microscope （AFM）, X-ray Photoelectron spectrum （XPS） and Auger electron spectrum （AES） methods. The results showerd that the performance of the dielectric does not descend after an 1000 h aging experiment. Therefore the thin dielectric layers of α-Al2O3 porcelain with a purity above 99% can sustain a long time action of DBD plasma and form gas ionization discharges steadily.展开更多
Effects of carrier gas composition（N2/air） on NH3 production, energy efficiency regarding NH3 production and byproducts formation from plasma-catalytic decomposition of urea were systematically investigated using an...Effects of carrier gas composition（N2/air） on NH3 production, energy efficiency regarding NH3 production and byproducts formation from plasma-catalytic decomposition of urea were systematically investigated using an Al2 O3-packed dielectric barrier discharge（DBD） reactor at room temperature. Results show that the presence of O2 in the carrier gas accelerates the conversion of urea but leads to less generation of NH3. The final yield of NH3 in the gas phase decreased from 70.5%, 78.7%, 66.6% and 67.2% to 54.1%, 51.7%, 49.6% and 53.4% for applied voltages of 17, 19, 21 and 23 kV, respectively when air was used as the carrier gas instead of N2.From the viewpoint of energy savings, however, air carrier gas is better than N2 due to reduced energy consumption and increased energy efficiency for decomposition of a fixed amount of urea. Carrier gas composition has little influence on the major decomposition pathways of urea under the synergetic effects of plasma and Al2 O3 catalyst to give NH3 and CO2 as the main products. Compared to a small amount of N2 O formed with N2 as the carrier gas, however,more byproducts including N2O and NO2 in the gas phase and NH4 NO3 in solid deposits were produced with air as the carrier gas, probably due to the unproductive consumption of NH3, the possible intermediate HNCO and even urea by the abundant active oxygen species and nitrogen oxides generated in air-DBD plasma.展开更多
基金supported by National Natural Science Foundation of China(Nos.20507004,21577023)
文摘For their distinguished global warming potential（GWP100）and long atmosphere lifespan,CF_4,SF_6 and SF_5CF_3were significant in the field of greenhouse gas research.The details of discharging character and the optimal parameter were discussed by using a Dielectric Barrier Discharge（DBD）reactor to decompose these potent greenhouse gases in this work.The results showed that SF_6 could be decomposed by 92% under the conditions of 5 min resident time and3000 V applied voltage with the partial pressure of 2.0 k Pa,28.2 k Pa,and 1.8 k Pa for SF_6,air and water vapor,respectively.0.4 k Pa CF_4 could be decomposed by 98.2% for 4 min resident time with 30 k Pa Ar added.The decomposition of SF_5CF_3 was much more effective than that of SF_6 and CF_4and moreover,1.3 k Pa SF_5CF_3,discharged with 30 k PaO_2,Ar and air,could not be detected when the resident time was 80 s,40 s,and 120 s,respectively.All the results indicated that DBD was a feasible technique for the abatement of potent greenhouse gases.
文摘A coaxial dielectric barrier discharge (DBD) reactor was used for plasma-catalytic degradation of tetracycline hydrochloride over a series of Mn/γ-Al2O3 catalysts prepared by the incipient wetness impregnation method.The combination of plasma and the Mn/γ-Al2O3 catalysts significantly enhanced the degradation efficiency of tetracycline hydrochloride compared to the plasma process alone,with the 10% Mn/γ-Al2O3 catalyst exhibiting the best tetracycline hydrochloride degradation efficiency.A maximum degradation efficiency of 99.3% can be achieved after 5 min oxidation and a discharge power of 1.3 W,with only 69.7% by a single plasma process.The highest energy yield of the plasma-catalytic process is 91.7 g kWh-1.Probable reaction mechanisms of the plasma-catalytic removal of tetracycline hydrochloride were also proposed.
基金financial support for this research was provided by National Natural Science Foundation of China (No. 21577023)the Key Project supported by the Science and Technology Commission of Shanghai Municipality (No. 15DZ1205904)Technology Innovation and Energy Saving Enhancement Project supported by Shanghai SASAC (No. 2013019)
文摘This paper discusses the removal of nitric oxide （NO） with low-temperature selective catalytic reduction driven by a dielectric barrier discharge with ammonia （NH3） as a reductant. We explored the effects of NH3, O2, temperature and water under different applied voltage on NO removal at atmospheric pressure. The results showed that when the gas concentration ration of NH3/NO was 0.23-0.67, the NO removal efficiency and the energy consumption was acceptable. The NO removal efficiency reached 84% under an applied voltage of 7 kV, 400 ppm NO and 90 ppm NH3 at a temperature of 150 ℃. Water vapor had a negative effect because NO formation reactions were strengthened and NH3 was oxidized directly rather than reduced NO molecules. The outlet gas components were observed via Fourier transform infrared spectroscopy for revealing the decomposition process and mechanism.
文摘In this paper, a study of homogenous dielectric barrier discharge Ar–NHwas made in order to investigate the electrical and the physical characteristics of homogenous discharge at atmospheric pressure. The discharge model includes the electrical module and the chemical kinetic module. The results obtained by the present model were compared with experimental work. The evolution of the plasmas voltage, the species densities, and the concentration of charged species are analyzed and discussed.
基金supported by the Program for Chang Jiang Scholars and Innovative Research Terms in Universities(No. IRT0936)the National Basic Research Program of China (No. 2009CB219905, 2009CB219907)
文摘A wire-mesh catalyst coated by La0.8Sr0.2MnO3 was combined with a dielectric barrier discharge （DBD） reactor for toluene removal at atmospheric pressure. It was found that toluene removal efficiency and carbon dioxide selectivity were enhanced in the catalytic packed-bed reactor. In addition, ozone and nitrogen monoxide from the gas effluent byproducts decreased. This is the first time that ultrasound combined with plasma has been used for toluene removal. A synergistic effect on toluene removal was observed in the plasma-assisted ultrasound system. At the same time, the system increased toluene conversion and reduced ozone emission.
基金supported by National Natural Science Foundation of China(No.60371035)Special Prophase Project on Basic Research of National Commission of Science and Technology(No.2004ccA06300)Project of Social Development of Dalian City(No.2004B3SF181)
文摘The performance of dielectric material is a key factor against a long time action in dielectric barrier discharge （DBD） plasma. In this study, the aging of the Al2O3 dielectric material was studied by the Atomic Force Microscope （AFM）, X-ray Photoelectron spectrum （XPS） and Auger electron spectrum （AES） methods. The results showerd that the performance of the dielectric does not descend after an 1000 h aging experiment. Therefore the thin dielectric layers of α-Al2O3 porcelain with a purity above 99% can sustain a long time action of DBD plasma and form gas ionization discharges steadily.
基金supported by the National Natural Science Foundation of China (Nos. 21547004, 51638001)the Beijing Natural Science Foundation (No. 8152011)the Scientific Research Program of Beijing Municipal Education Commission (No. KM201510005009)
文摘Effects of carrier gas composition（N2/air） on NH3 production, energy efficiency regarding NH3 production and byproducts formation from plasma-catalytic decomposition of urea were systematically investigated using an Al2 O3-packed dielectric barrier discharge（DBD） reactor at room temperature. Results show that the presence of O2 in the carrier gas accelerates the conversion of urea but leads to less generation of NH3. The final yield of NH3 in the gas phase decreased from 70.5%, 78.7%, 66.6% and 67.2% to 54.1%, 51.7%, 49.6% and 53.4% for applied voltages of 17, 19, 21 and 23 kV, respectively when air was used as the carrier gas instead of N2.From the viewpoint of energy savings, however, air carrier gas is better than N2 due to reduced energy consumption and increased energy efficiency for decomposition of a fixed amount of urea. Carrier gas composition has little influence on the major decomposition pathways of urea under the synergetic effects of plasma and Al2 O3 catalyst to give NH3 and CO2 as the main products. Compared to a small amount of N2 O formed with N2 as the carrier gas, however,more byproducts including N2O and NO2 in the gas phase and NH4 NO3 in solid deposits were produced with air as the carrier gas, probably due to the unproductive consumption of NH3, the possible intermediate HNCO and even urea by the abundant active oxygen species and nitrogen oxides generated in air-DBD plasma.
