四種等離子形態(tài)凈化技術(shù)

1、 四種等離子形態(tài)凈化技術(shù) 等離子體是含有大量電子、離子、分子、中性原子、激 發(fā)態(tài)原子、 光子和自由基等組成的物質(zhì)的第四種形態(tài)。 其總 正負(fù)電荷數(shù)相等宏觀上呈電中性， 但具有導(dǎo)電和受電磁影響 的性質(zhì)，表現(xiàn)出很高的化學(xué)活性。根據(jù)體系能量狀態(tài)、溫度 和離子密度， 等離子體通?？煞譃楦邷氐入x子體和低溫等離 子體(包括熱等離子體和冷等離子體) 。高溫等離子體的電 離度接近， 各種粒子的溫度幾乎相同， 并且體系處于熱力學(xué) 平衡狀態(tài)， 它主要應(yīng)用于受控?zé)岷朔磻?yīng)研究方面。 低溫等離 子體則處于熱力學(xué)非平衡狀態(tài)，各種粒子溫度并不相同。Plasma is contains a lot of electrons,

2、ions, molecules, neutral atoms, excited atoms and photons and free radicals of material such as the fourth form. It equals the total number of positive and negative charges on macro is electrically neutral, but has the properties of conductive and electromagnetic influence, showing a high chemical a

3、ctivity. According to system energy state, temperature and ion density, plasma is usually divided into high temperature plasma and low temperature plasma (including hotcold plasmaand plasma). Close to high temperature plasma ionization degree, all kinds of particle temperatureis almost the same, and

4、 the system is in a state of thermodynamic equilibrium, it is mainly used in controlled thermonuclear reaction research. Low temperature plasma is in a state of non-equilibrium thermodynamics, a variety of particle temperature is not the same.低溫等離子體可通過(guò)前沿陡、脈寬窄(納秒級(jí))的高壓脈沖放電在常溫常壓下獲得，其中的高能電子和O 0HCO HC NO

5、X SOX H2SRSH等發(fā)生作用，轉(zhuǎn)化為 CO2 H2O N2、S、SO2等無(wú)害或 低害物質(zhì)，從而使廢氣得到凈化。它可促使一些在通常條件下不易進(jìn)行的化學(xué)反應(yīng)得以進(jìn)行，甚至在極短時(shí)間內(nèi)完成， 故屬低濃度vocs臺(tái)理的前沿技術(shù)。Low temperature plasma can be through the frontsteep pulse width (nanosecond) under high voltage pulse discharge in the normal temperature atmospheric pressure, the high energy electron a

6、nd O & # 61655;,OH, & # 61655; And other active particles can with all kinds of pollutants such as CO, HC and NOX, SOX, H2S,RSH, converted into C02, H20, N2, S, harmless or less harmful material such as SO2, which makes exhaust gas purification. It may prompt some chemical reaction under the conditi

7、on of usually not easy to possible, even in a very short time, so it belongs to the low concentration of VOCs treatment at the forefront of technology.1.2協(xié)同作用機(jī)理1.2 coordination mechanism低溫等離子體和催化協(xié)同作用處理廢氣的主要原理等離子體中可源源不斷地產(chǎn)生大量極活潑的高活性物種，這在普通的熱化學(xué)反應(yīng)中不易得到，這些活性物種（特別是高能電子）含有巨大的能量，可以引發(fā)位于等離子體附近的催化 劑，并可降低反應(yīng)的活化能

8、。同時(shí)，催化劑還可選擇性地促進(jìn)等離子體產(chǎn)生的副產(chǎn)物反應(yīng)，得到無(wú)污染的物質(zhì)。但是目前國(guó)內(nèi)外在等離子體和催化協(xié)同作用機(jī)理方面的分析和研 究比較少，在這方面的認(rèn)識(shí)還遠(yuǎn)遠(yuǎn)不夠。Low temperature plasma and catalytic synergy processing waste gas in the main principle of the plasma can be continuously produced a large number of highly reactive species extremely lively, it is not easy to get in

9、the common thermal chemical reaction, these active species (especially high energy electron) contains vast amounts of energy, can trigger near plasma catalyst, and can reduce the activation energy of reaction. At the same time, the catalyst can selectively promote plasma by-product generated in the

10、reaction, non-pollution material. But at home and abroad in the plasma and catalytic mechanism of synergy of less analysis and research, in this respect knowledge is not enough.有學(xué)者認(rèn)為，固相催化劑的活性是由它們的化學(xué)和物相 組成，晶體結(jié)構(gòu)以及活性比表面所決定。在等離子體的作用下，催化劑表面將形成超細(xì)顆粒(平均顆粒直徑為5-500nm，比表面約為100 m2/g)，這將大大增加催化劑的比表面積， 并且破壞催化劑的晶體結(jié)

11、構(gòu)，鋼塑土工格柵擁有更多的空 穴，從而導(dǎo)致高的催化活性。相比普通的催化劑，等離子體作用后的催化劑有如下獨(dú)特之處： 具有高度分布的活性物 種，能耗減少，加強(qiáng)了催化劑的活性和選擇性，延長(zhǎng)了催化劑壽命；縮短了制備時(shí)間。另外，等離子體的作用可促進(jìn)催化劑中的組分均勻分布，降低對(duì)毒物的敏感程度。這些特性將使得等離子體一催化技術(shù)有更大的應(yīng)用前景。The scholar thinks, the activity of solid catalyst is by their chemical and phase composition, crystal structure and surface activity

12、 than the decision. Under the action of plasma and catalyst surface will form ultrafine particles (average particle diameter of 5-500 - nm, specific surface is about 100 m2/ g), which will greatly increase the specific surface area of catalyst, and damaging the catalyst crystal structure, it has mor

13、e holes, leading to high catalytic activity. Compared with the ordinary catalyst, catalyst after the plasma function has the following unique: 1) a highly distributed active species, (2) to reduce energy consumption, (3) strengthen the catalyst activity and selectivity, extend the service life of th

14、e catalyst; (4) to shorten the preparation time. In addition,therole ofthe plasmacan promotethecatalystisuniformdistribution,reducethesensitivity of poison. These features willmake plasma-catalytic technology has more application prospects.2.研究進(jìn)展2. The research progress歐美和日本等國(guó)對(duì)低溫等離子體催化技術(shù)的研究開(kāi)展得比較早，主要

15、把該技術(shù)應(yīng)用于脫硫脫硝、消除揮發(fā)性有機(jī)化合物、凈化汽車尾氣、治理有毒有害化合物等方面。目前，很多國(guó)家的學(xué)術(shù)機(jī)構(gòu)、政府和商業(yè)機(jī)構(gòu)都在積極地開(kāi)展此類研究。近年來(lái)，國(guó)內(nèi)有很多學(xué)者在等離子體煙氣脫硫脫硝、 汽車尾氣凈化、有機(jī)廢氣處理等方面取得了較多實(shí)驗(yàn)結(jié)果， 在這方面的研究已比較成熟。Europe and the United States and Japan and other countries the study of low temperature plasma catalysis technology develops early, mainly apply the technology t

16、o the desulfurization denitration,elimination of volatile organic compounds, purifying automobile exhaust, governance, poisonous and harmful compounds, etc. At present, academic institutions, government and business organizations in many countries are actively conducting such research. In recent yea

17、rs, there are a lot of domestic scholars in plasma flue gas desulfurization denitration, car tail gas purification, organic waste gas treatment more experimental results are obtained, in this aspect of the research is relatively mature.3.1處理VOCs進(jìn)展3.1 VOCs processing progress國(guó)內(nèi)外大量研究表明，等離子體-催化協(xié)同作用相比單個(gè)

18、作用時(shí)能大大增強(qiáng)凈化效果。Kang M等人在常壓下用等離子體/TiO2催化體系去除苯，催化劑的質(zhì)量百分比為3%苯的濃度為1000 mg/m3,在僅有氧氣等離子體沒(méi)有TiO2催化劑時(shí)，40%勺苯分解；在 TQ2/O2等離子體下，脫除率達(dá) 到70% 在O2等離子體中，TiO2負(fù)載于丫 -AI2O3上時(shí)甲苯 的轉(zhuǎn)化率達(dá)到80%At home and abroad a large number of studies have shown that plasma - catalytic synergy when compared to a single role can greatly enhance

19、the purification effect. Kang M and others under ordinary conditions of benzene by the plasma/TiO2 catalysts, catalyst quality percentage is 3%, the benzene concentration of 1000 mg/m3, when only oxygen plasma no TiO2 catalyst, 40% of benzene decomposition; In the TiO2 / O2 plasma, the removal rate

20、of 70%; TiO2 in O2 plasma load in gamma Al2O3 on toluene conversion rate reached 80%.Futamura S等對(duì)有害大氣污染物(HAP在低溫等離子 體化學(xué)處理中金屬氧化物的催化活性進(jìn)行了研究，在沒(méi)有 Mn02作催化劑時(shí)，苯的摩爾轉(zhuǎn)化率為30%而在有 Mn02作催化劑時(shí)，苯的摩爾轉(zhuǎn)化率可以大大提高。Franeke K P等人研究指出，在僅有催化劑時(shí)，20%的DCE二氯乙烯)轉(zhuǎn)化成CO2僅放電條件下，轉(zhuǎn)化70%的 DCE只有當(dāng)兩者協(xié)同作用時(shí)，有90%的 DCE被去除，并且 C02為主要氧化產(chǎn)物。Futamura S

21、on hazardous air pollutants (HAP) in thelow temperature plasma chemical treatment of metal oxide catalytic activity was studied, in the absence of Mn02 as catalyst, the molar conversion of benzene is 30%, and in the MnO2 as catalyst, the molar conversion of benzene can be greatly improved. Franeke K

22、 P et al. Research suggests that in catalyst, only 20% of the DCE(vinyl chloride) is converted into CO2; Only discharge condition, the conversion of 70%of the DCE; Only when both synergy, 90%of the DCEhas been removed, and CO2 as the main oxidation products.秦張峰等應(yīng)用低溫等離子體催化凈化甲苯廢氣，采用了含CuO Pd、Pt等活性組分的催化

23、劑，當(dāng)反應(yīng)氣流速為50-500 mL/min，甲苯初始濃度為 2000-20000 mg/m3時(shí)，甲 苯去除率為70%-95%脫除量可達(dá)110 mg/ho李鍛等將雙極 性脈沖高壓引入介質(zhì)阻擋反應(yīng)器對(duì)氯苯和甲苯的分解特性 進(jìn)行了實(shí)驗(yàn)研究，而以馮春楊、晏乃強(qiáng)和黃立維等人開(kāi)展了 脈沖電暈去除多種有機(jī)廢氣的研究，初始濃度為76.8mg/m3,苯的去除率達(dá)到61.4%，并對(duì)比了線一筒式和線一板式二種反應(yīng)器對(duì)甲苯的去除率，在以Mn Fe等作為催化劑時(shí)，可使去除率提高，催化劑活性的排序?yàn)镸n FeCo Ti Ni Pd Cu V在去除各種有機(jī)廢氣中，甲醛最易 去除，二氯甲烷最難，甲苯、乙醇、丙酮?jiǎng)t處于其間。

24、Qin zhang, etc. Application of low temperature plasma catalytic toluene waste gas purification, adopted the CuO, Pd, Pt, such as active component of catalyst, when reaction gas flow rate is 50-500 mL/min, the initial concentration is 2000-20000 mg/m3, the removal rate of toluene is 70% - 95%, removing the am