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1、http:/ http:/ http:/ ttp:/汽车尾气去除浓度效率进展Rajanikanth B S等人对模拟气体在等离子体放电催化中NOx的去除进行了实验研究,指出介质填充床的存在可使NO在低电压下有更高的去除效率。实验对三种不同的催化剂(Al2O3、BaTiO3、Al2O3 + Pd)进行了探讨,发现BaTiO3颗粒在气体组成为NO、O2、N2以及NO在N2中时有更高的去除效率。在NO的初始浓度为265 mg/m3时,NO的去除效率几乎达到99%。在模拟汽车尾气(组成为NOO2CO2N2 )中,相比其他介质,涂了Pd的Al2O3催化剂有更高的NO去除效率,在室温下NO去除效率相当于3
2、00甚至更高温度下尾气在惯常催化剂作用下的效率。Rajanikanth B S waiting for simulation of gas in the plasma discharge in the catalytic removal of NOx has carried on the experimental research, points out that the medium is the existence of the packed bed can make NO has a higher removal efficiency under low voltage. Experim
3、ents on three different kinds of catalyst (Al2O3, BaTiO3, Al2O3 + Pd) are discussed in this paper, found the BaTiO3 particles in gas composition to NO, O2, N2, and NO had higher removal efficiency in N2. In NO initial concentration of 265 mg/m3, the NO removal efficiency of almost 99%. In simulation
4、 of automobile exhaust (composition to NO, O2, CO2, N2), compared to other media, with Pd Al2O3 catalysts have higher the NO removal efficiency, NO removal efficiency at room temperature about 300 or higher temperature exhaust gas under the usual catalyst efficiency. Franeke K P等10研究指出,仅在放电条件下,部分NO被
5、氧化成NO2;在仅有氨作为还原剂,沸石作为催化剂时,可去除20%的NO;当等离子体置于催化之后,仅少量NO氧化成NO2;放电置于催化之前,约50%NO被去除;而当等离子体靠近催化放置时,有超过80 %的NO转化成N2。Franeke K P 10, such as research, points out that only under the condition of discharge, part NO was oxidized into NO2; In only ammonia as a reductant, zeolite as a catalyst, can remove 20% o
6、f NO; After the plasma in catalysis, only a small amount of the NO oxidation into NO2; Before discharge in catalytic, about 50% of the NO be removed; When placed near plasma catalysis, more than 80% of the NO into N2. 3.3 净化机动车尾气进展3.3 progress in motor vehicle exhaust purification 为实现美国环保局(EPA)提出的机动
7、车尾气中NOx必须还原90%以上的目标,等离子体协同的催化体系在治理机动车排气方面有了很大进展。目前,用该项技术NOx的还原效率可达到65%以上,同时,该项技术还可脱除92%96%的颗粒物,去除甲醛40%以上。To achieve the environmental protection agency (EPA) proposed by motor vehicle exhaust gas in the NOx reduction 90% above target, plasma TiXie with catalytic system has made great progress in the
8、 aspect of management of motor vehicle exhaust. At present, with the technology of NOx reduction efficiency can reach above 65%, at the same time, the technology can also be removed 92% 96% of the particulate matter, removal of formaldehyde by more than 40%. 美国学者指出,在富氧废气中采用低温等离子体技术处理汽车尾气,可使NO在O2和碳氢化
9、合物的协同作用下转变为NO2。而随后的金属氧化物催化剂可使NO2转化为N2。该方法强化了机动车排气中氮氧化物的还原,特别是那些有相对较高硫含量的汽车尾气。Miessner H等11也指出,SCR和低温等离子体相结合净化机动车排气,加强了整体反应,在相对低的温度下就能有效地去除NOx。Al2O3和ZrO2作为催化剂的加入,促进了反应向有利方向进行。当吊车供给每个NO分子30 ever的能量,温度为300,气速为20000 /h时,500 mg/m3的NO能还原一半以上。American scholars pointed out that using low temperature plasma
10、technology in the oxygen-enriched gas processing, automobile exhaust can make NO under the synergy of O2 and hydrocarbons into NO2. And then the metal oxide catalyst can make the NO2 into N2. The method to strengthen the nox reduction in motor vehicle exhaust, especially those who have a relatively
11、high sulfur content of automobile exhaust. Miessner H 11 also pointed out, such as SCR and combination of low temperature plasma purification of motor vehicle exhaust, strengthened the overall reaction, at relatively low temperatures can effectively remove NOx. Of Al2O3 and ZrO2 as a catalyst to joi
12、n, to promote the reaction to the favorable direction. When every 30 (NO molecular energy supply, the temperature is 300 , the gas velocity is 20000 / h, 500 mg/m3 can NO reduction of more than half. 国内学者发明了一种后置式汽车尾气净化器,尾气经锥体分散后进入电场的催化剂中,在低温等离子体和催化剂的协同作用下,尾气净化率大大提高。该净化器一方面可使催化剂活性增加,转化率提高;另一方面可避免催化剂烧
13、结,从而降低汽车尾气中有害气体的排放。与现有技术相比,该净化器具有以下优点:将酿酒设备低温等离子体技术与催化技术相结合,技术得到升级;适用于各种车型,不受汽车的原始排放限制,不同于现有的三元催化装置;没有起燃温度限制,对冷车启动同样有效,且适用范围广;结构紧凑,设计独特、新颖。Domestic scholars invented a rear type automobile exhaust purifier, exhaust after cones scattered into the catalyst of the electric field, under the low temperat
14、ure plasma and catalyst synergism, exhaust gas purification rate is greatly increased. The purifier can increase the catalyst activity on one hand, conversion efficiency; On the other hand can avoid catalyst sintering, to reduce emissions of harmful gas in tail gas. Compared with the existing techno
15、logy, the purifier has the following advantages: (1) the low temperature plasma technology combined with a catalytic technology, technology upgrade; (2) suitable for all kinds of vehicles, vehicle emission of the original without limit, is different from the existing ternary catalytic device; (3) th
16、ere is no limit to the light-off temperature of cold start as effective, and the applicable range is extensive; 4. Compact structure, unique design, novel. 3. 展望3. Look forward to 低温等离子体技术应用的可行性和条件试验已较充分,也有了大量理论基础,已为这项工艺简单、适用性强、流程短、能耗低、易于操作和自动化的新技术早日工业化打下了充分的基础。但在低温等离子体技术与催化协同作用方面研究较少,是一项全新的处理技术,二者相结合,等离子体场产生高能量活性粒子,促进催化反应,减少能耗;催化主导反应方向,让反应具有选择性,并能大大减少反应副产物