首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 101 毫秒
1.
脉冲电晕环境中13X分子筛对NO分解作用的研究   总被引:2,自引:0,他引:2  
在常温、常压下,利用脉冲电晕放电产生冷等离子体,使一氧化氮发生分解,直接生成氮气和氧气,用四极杆质谱仪在线测量反应过程中反应物和生成物的变化。在自行研制的实验台上,考察了13X分子筛在不同的脉冲电晕放电条件下,表现出来的不同特性及其对反应转化率的影响。在30 ℃~430 ℃、流量375 mL/min~1 333 mL/min,分析了该反应过程中13X分子筛对转化率的促进作用。在同一脉冲放电条件下,控制13X分子筛的温度为200 ℃,转化率从30 ℃时的1.2%上升到19.7%;转化率最高可以达到35.9%。并对反应过程中13X分子筛的吸附特性做了初步探讨。  相似文献   

2.
This study examined the discharge property of methane in a pulsed plasma using single and sequential pulse modes. A pulsed corona discharge occurred, followed by a pulsed spark discharge. An equivalent single channel model (ESC model) for the pulsed plasma of methane was established. The maximum temperature of methane in the discharge channel was estimated. The pyrolysis property of the channel methane was estimated from Senkin simulation and single channel discharge experiment.  相似文献   

3.
Trichloroethylene (TCE) and vinyl chloride (VC) removal by gas phase pulsed corona discharge was investigated with attention to energy efficiency and byproduct identification. Approximately 50–95% removal of TCE and vinyl chloride was observed, depending on the energy density applied to the gas. Water vapor reduced TCE removal in some experiments. Evidence was found for post-corona reactions leading to removal of vinyl chloride downstream of the plasma discharge, while significant post-corona removal of TCE was not observed. Removal efficiencies of 100–900 g/kW-hr in the case of 1000 ppm feed of TCE, and of 2–24 g/kW-hr for a 100 ppm feed of vinyl chloride were found. In the TCE experiments, the formation of dichloroacetyl chloride was observed, while an unknown byproduct was found with vinyl chloride. The addition of a platinum-rhodium coated electrode was found to reduce the post-corona removal of vinyl chloride at low energy density.  相似文献   

4.
The decomposition of methylene blue (MB) in aqueous solution was investigated using a pulsed corona discharge. The discharge was ignited in the gas bubbled in the solution through several needle electrodes. The influence of treatment time, volume of the treated solution and initial concentration of the dye in solution on MB degradation was studied. The effect of the nature of the gas introduced was also investigated. For the same energy input, MB conversion increased in the order air < argon < oxygen. When using oxygen, the decomposition of MB exceeded 95% after ~20 min plasma treatment. Higher efficiency was obtained for higher treated volume and higher initial concentration. At 90% conversion the yield obtained with oxygen was ~5 g/kWh for an initial concentration of 150 mg/l and a treated volume of solution of 100 ml.  相似文献   

5.
Experiments are performed to develop a pulsed corona discharge system for the conversion ofmethane to hydrogen at atmospheric pressure (≌760 Torr) without using a catalyst. The corona dischargewas energized by 10-12 μs wide voltage pulses (≤7 kV) at a repetition rate of about 1.0-1.5 kHz. Theresidual gases were characterized by mass spectrometry. The conversion of methane is as high as 50.8% producing the 70% yield of hydrogen. The influences of argon on the discharge of methane were studied.This result could be useful for the mass production of hydrogen in both academic and industrial point ofview.  相似文献   

6.
The authors recently developed a high-frequency pulsed plasma process for methane conversion to acetylene and hydrogen using a co-axial cylindrical (CAC) type of reactor. The energy efficiency represented by methane conversion rate per unit input energy has been improved so that such a pulsed plasma has potential for commercial acetylene production. A pulsed plasma consists of a pulsed corona discharge and a pulsed spark discharge. Most of energy is injected over the duration of the pulsed spark discharge. Methane conversion using this kind of pulsed plasma is a kind of pyrolysis enhanced by the pulsed spark discharge. In this study, a point-to-point (PTP) type of reactor that can produce a discharge channel over the duration of a pulse discharge was used for the pulsed plasma conversion of methane. The energy efficiency and carbon formation on electrodes have been improved. The influences of pulse frequency and pulse voltage on methane conversion rate and product selectivity were investigated. The features of methane conversion using PTP and CAC reactors were discussed.  相似文献   

7.
OH radical in the corona discharge with pipe–nozzle–plate electrode has been diagnosed by optical emission spectroscopy. Spatial variations of OH radical emission in discharge gap have been measured. Relative intensity of OH radical emission spectroscopy increases with increasing water vapor flux injected into the reactor or intensity of electric field supported. In positive pulsed corona discharge, relative intensity is higher than that in positive DC corona discharge and lower than that in negative DC corona discharge. Strongest intensity of OH radical spectrum appears within the range of 5 mm near the discharge nozzle- electrode. In addition, it is proved that the efficiency of desulphurization from flue gas by pulsed corona discharge plasma processes can be improved when OH radical is produced in the reactor.  相似文献   

8.
Pulsed discharge deNO x /deSO2 process has been studied for over 20 years, but how to achieve higher removal rate at lower cost remains one of the crucial issues for realization of its industrial application. This paper presents a novel deNO x /deSO2 process that combines a wire-plate type pulsed discharge reactor and a corona radical shower. Our aim is to increase the deNO x /deSO2 rate of wire-plate type reactor by enhancing the generation of radicals with pulsed corona radical shower. Effect of a nozzle electrode on the production of OH radical was studied by emissive spectrum, and deNO x /deSO2 experiments using a wire-plate reactor with pulsed corona radical shower were conducted. The experimental results demonstrated that corona radical shower could enhance the production of radicals and the deNO x /SO2 performance of a wire-plate reactor. This study will play a positive role in the industrial application of wire-plate pulsed discharge deNO x /deSO2 reactor.  相似文献   

9.
Plasma oxidation of ethanethiol in air was investigated using three plasma regimes: surface dielectric pulsed corona discharge, surface dielectric barrier discharge and pulsed corona discharge (PCD) in the plasma reactor. Catalytic plasma degradation of ethanethiol was also performed on the singular or binary metals doped ?èCAl2O3. The ethanethiol removal rate increased with increasing energy density but energy efficiency was first increased and then decreased with increasing energy density under three various types of discharges. PCD plasma required the lowest energy density at the similar ethanethiol removal performance compared with the other two plasma discharges. The main intermediate by-products of ethanethiol oxidation by plasma are CH3CHO, HCHO, CO and CO2. The sum of these intermediate products selectivities is 19?C43?%, implying that some other intermediates containing carbon were undetermined. When using PCD plasma combined with catalysts, ethanethiol removal rate and energy efficiency were all evidently improved. The maximum energy efficiency was achieved about 200?g kWh?1 using Fe?CMn/?èCAl2O3 assisted PCD plasma, which was about 4.4 times when using PCD plasma alone. The mechanism of ethanethiol oxidation is also discussed.  相似文献   

10.
二氯甲烷在担载型三氧化铬催化剂上的催化降解   总被引:1,自引:0,他引:1  
本文研究了二氯甲烷在不同的担载型CrO_3催化剂上的催化降解.实验揭示:碳纤维的单丝直径粗细,吸附能力,ZSM-5沸石中晶格外铝的含量以及Al_2O_3的形貌与物相等均明显影响催化剂的催化活性与选择性.文中对不同的载体作了比较,还对活性组分CrO_3的铬的价态,用氢气还原与空气灼烧两种预处理对催化行为的影响进行了讨论.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号