過濾復(fù)合等離子體催化降解萘的研究
發(fā)布時間：2018-07-24 16:27
【摘要】：多環(huán)芳烴(PAHs)由于其具有三致(致癌、致畸、致突變)作用,在近年來受到越來越多的關(guān)注。其作為一類大氣污染物,會引發(fā)環(huán)境產(chǎn)生的一系列負(fù)面問題,同時會對生物產(chǎn)生毒害作用。同時伴隨近年來霧霾天氣,大氣中氣溶膠顆粒物增多,PAHs能吸附在氣溶膠顆粒物微孔結(jié)構(gòu)中而較為長久的停留在大氣中,產(chǎn)生更為嚴(yán)重的污染。因此,對PAHs排放控制問題已迫在眉睫。過濾復(fù)合等離子體催化技術(shù)能在去除萘的同時,對萘的降解產(chǎn)物和臭氧也能達(dá)到良好地去除效果。該方法處理效率高,能耗低以及副產(chǎn)物少的優(yōu)點。本研究以去除大氣中有機污染作為首要目標(biāo),為了方便研究,選取了一種最具代表性的物質(zhì)采用介質(zhì)阻擋放電(DBD)研究了萘在不同反應(yīng)器(過濾式反應(yīng)器和非過濾式反應(yīng)器)條件下的去除特性,并結(jié)合催化技術(shù)對其降解進(jìn)行探究。重點研究了萘在過濾式反應(yīng)器內(nèi)的去除效果及影響因素(初始濃度和能量密度),同時分析了顆粒物生成特點和萘降解機理;本實驗中比較三種催化劑與作為催化劑載體γ-A1203的作為主要催化劑,實驗溫度和銀負(fù)載量等對萘去除效果的影響,研究結(jié)果表明:(1)在兩種不同的反應(yīng)器條件下,能量密度的提升會使萘的去除率和COx的選擇率均增大,而萘初始濃度的提升會致使萘的去除率和COx選擇減小。對比兩種反應(yīng)器在介質(zhì)阻擋放電條件下萘去除率和COx選擇,得知過濾式反應(yīng)器對萘的降解效果要優(yōu)于非過濾式反應(yīng)器。而對比氣溶膠顆粒物濃度數(shù)據(jù)可知,非過濾反應(yīng)器內(nèi)顆粒物單粒徑下數(shù)量濃度峰值和總數(shù)量濃度為5.45E+06#/cm3和5.04 E+07#/cm3,而相同條件下過濾式反應(yīng)器僅為8.43E+02#/cm3和2.0E+04#/cm3。由此可見,過濾式反應(yīng)器對萘具有更好的降解效果,同時能非常有效地去除萘降解過程中產(chǎn)生的顆粒物,避免了傳統(tǒng)等離子技術(shù)降解有機廢氣導(dǎo)致大量氣溶膠顆粒物生成的缺點。(2)過濾式反應(yīng)器中萘的去除率和COx選擇性會受到溫度、初始濃度以及氧氣含量的影響�？梢钥闯�,氧氣含量的和溫度提升都會對萘的去除率和COx選擇性產(chǎn)生積極影響,而萘的初始濃度的增加則會導(dǎo)致兩者不同程度的減小。初始濃度為25 ppm時放電生成的顆粒物主要集中于10-24 nm粒徑段;當(dāng)濃度為100 ppm時,會出現(xiàn)10-19 nm和62-91 nm兩個粒徑段;當(dāng)濃度為100 ppm時,顆粒物歷經(jīng)范圍落在了 68-217 nm之間。由此可以看出,增加萘的初始濃度會使放電生成的顆粒物粒徑段發(fā)生改變,產(chǎn)生向大粒徑段遷移的趨勢。(3)BET數(shù)據(jù)顯示了負(fù)載催化劑后γ-A1203小球結(jié)構(gòu)的變化情況,可以看到比表面積與總孔孔容均出現(xiàn)不同程度下降。而Ag/γ-A1203的XPS表征結(jié)果說明通過利用浸漬法并煅燒后,Ag元素被成功負(fù)載于γ-A1203小球上。在等離子體區(qū)域之后填充不同種類的催化劑能促進(jìn)萘的降解,提升萘的去除率和COx選擇性。其原理主要是利用等離子體對萘進(jìn)行初步降解后,再將氣體通入后置催化劑區(qū)域,利用催化劑促使臭氧分解成活性氧原子并且進(jìn)一步降解萘及其中間產(chǎn)物。填充催化劑后,各催化劑對萘去除率的依次為:Ag/γ-Al2O3Mn/γ-Al2O3≈Co/γ-Al2O3γ-Al2O3,而對于COx選擇性的影響也呈現(xiàn)相似趨勢,同時可以添加催化劑對臭氧和顆粒物都有良好的去除效果。溫度的升高會提升Ag/γ-A1203催化氧化萘及其降解中間產(chǎn)物的效果,同時對COx選擇性具有促進(jìn)作用。而5%銀負(fù)載量是最佳值,對COx選擇性最好。
[Abstract]:Polycyclic aromatic hydrocarbons (PAHs) have attracted more and more attention in recent years because of their three (carcinogenic, teratogenic and mutagenic) effects. As a class of atmospheric pollutants, they will cause a series of negative environmental problems and toxic effects on the organisms. At the same time, with the haze weather in recent years, the aerosol particles in the atmosphere increase, PAHs It can be adsorbed in the microporous structure of aerosol particles and stay in the atmosphere for a long time and produce more serious pollution. Therefore, the control of PAHs emission is imminent. The filtration compound plasma catalysis technology can remove naphthalene and the degradation products of naphthalene and ozone can also be well removed. This method is treated by this method. With the advantages of high efficiency, low energy consumption and less by-products, this study aims to remove the organic pollution in the atmosphere as the primary goal. In order to facilitate the study, a most representative material is selected by dielectric barrier discharge (DBD) to study the removal characteristics of naphthalene under the conditions of different reactors (filter reactor and non filter reactor). The removal efficiency and the influence factors (initial concentration and energy density) of naphthalene in the filter reactor were studied, and the formation and degradation mechanism of the particles were analyzed. In this experiment, the three catalysts were compared with the catalyst carrier gamma -A1203 as the main catalyst and the experimental temperature. The effect of the amount of silver loading on the removal of naphthalene was found. The results showed: (1) the removal rate of naphthalene and the selection rate of COx increased with the increase of the energy density under the two different reactor conditions, while the enhancement of the initial naphthalene concentration would lead to the reduction of naphthalene and the reduction of the COx selection. The comparison of two kinds of reactors under the condition of dielectric barrier discharge The removal efficiency and COx selection showed that the degradation effect of naphthalene was better than that of non filter reactor. Compared with the aerosol particle concentration data, the concentration peak and total number concentration under the single particle size of the non filter reactor were 5.45E+06#/cm3 and 5.04 E+07# /cm3, while the filter reactor under the same condition was only 8. .43E+02#/cm3 and 2.0E+04#/cm3. show that the filter reactor has a better degradation effect on naphthalene, and can effectively remove the particles produced in the naphthalene degradation process, and avoid the disadvantages of the traditional plasma technology for the formation of large amount of aerosol particles resulting from the degradation of organic waste gases by plasma technology. (2) the removal rate of naphthalene and COx in the filter reactor. Selectivity is affected by temperature, initial concentration and oxygen content. It can be seen that both the oxygen content and the temperature increase have a positive effect on the removal rate of naphthalene and the selectivity of COx, while the increase of the initial concentration of naphthalene will lead to the decrease of the two degrees. The particles generated by the initial concentration of 25 ppm are mainly concentrated on the particles. 10-24 nm particle size section; when the concentration is 100 ppm, there will be 10-19 nm and 62-91 nm segments. When the concentration is 100 ppm, the range of particles falls between 68-217 nm. Thus, it can be seen that the increase of the initial concentration of naphthalene will change the particle size of the particles generated by the discharge, and produce the trend to migrate to the large size segment. (3) BET data. The changes in the structure of the gamma -A1203 ball after the loading of the supported catalyst showed that the specific surface area and the pore volume of the total pore decreased in varying degrees. The XPS characterization results of the Ag/ gamma -A1203 showed that the Ag element was successfully loaded on the gamma -A1203 pellets by impregnation and calcined. After the plasma region, different kinds of urges were filled. The chemical agent can promote the degradation of naphthalene and enhance the removal rate of naphthalene and the selectivity of COx. The principle is to use the plasma to degrade naphthalene, and then pass the gas into the post catalyst area, use the catalyst to decompose the ozone into the living oxygen atom and further degrade the naphthalene and the inter product. The removal rate of naphthalene is as follows: Ag/ gamma -Al2O3Mn/ gamma -Al2O3 Co/ gamma -Al2O3 gamma -Al2O3, which also has a similar tendency to the effect of COx selectivity. At the same time, the catalyst can have good removal effect on both ozone and particles. The increase of temperature will enhance the effect of Ag/ gamma -A1203 catalytic oxidation naphthalene and the degradation of intermediate products. Meanwhile, COx is selected for COx. Selectivity has a promoting effect, while the 5% silver load is the best value and the best selectivity for COx.
【學(xué)位授予單位】：浙江工商大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：X51
本文編號：2141963
[Abstract]:Polycyclic aromatic hydrocarbons (PAHs) have attracted more and more attention in recent years because of their three (carcinogenic, teratogenic and mutagenic) effects. As a class of atmospheric pollutants, they will cause a series of negative environmental problems and toxic effects on the organisms. At the same time, with the haze weather in recent years, the aerosol particles in the atmosphere increase, PAHs It can be adsorbed in the microporous structure of aerosol particles and stay in the atmosphere for a long time and produce more serious pollution. Therefore, the control of PAHs emission is imminent. The filtration compound plasma catalysis technology can remove naphthalene and the degradation products of naphthalene and ozone can also be well removed. This method is treated by this method. With the advantages of high efficiency, low energy consumption and less by-products, this study aims to remove the organic pollution in the atmosphere as the primary goal. In order to facilitate the study, a most representative material is selected by dielectric barrier discharge (DBD) to study the removal characteristics of naphthalene under the conditions of different reactors (filter reactor and non filter reactor). The removal efficiency and the influence factors (initial concentration and energy density) of naphthalene in the filter reactor were studied, and the formation and degradation mechanism of the particles were analyzed. In this experiment, the three catalysts were compared with the catalyst carrier gamma -A1203 as the main catalyst and the experimental temperature. The effect of the amount of silver loading on the removal of naphthalene was found. The results showed: (1) the removal rate of naphthalene and the selection rate of COx increased with the increase of the energy density under the two different reactor conditions, while the enhancement of the initial naphthalene concentration would lead to the reduction of naphthalene and the reduction of the COx selection. The comparison of two kinds of reactors under the condition of dielectric barrier discharge The removal efficiency and COx selection showed that the degradation effect of naphthalene was better than that of non filter reactor. Compared with the aerosol particle concentration data, the concentration peak and total number concentration under the single particle size of the non filter reactor were 5.45E+06#/cm3 and 5.04 E+07# /cm3, while the filter reactor under the same condition was only 8. .43E+02#/cm3 and 2.0E+04#/cm3. show that the filter reactor has a better degradation effect on naphthalene, and can effectively remove the particles produced in the naphthalene degradation process, and avoid the disadvantages of the traditional plasma technology for the formation of large amount of aerosol particles resulting from the degradation of organic waste gases by plasma technology. (2) the removal rate of naphthalene and COx in the filter reactor. Selectivity is affected by temperature, initial concentration and oxygen content. It can be seen that both the oxygen content and the temperature increase have a positive effect on the removal rate of naphthalene and the selectivity of COx, while the increase of the initial concentration of naphthalene will lead to the decrease of the two degrees. The particles generated by the initial concentration of 25 ppm are mainly concentrated on the particles. 10-24 nm particle size section; when the concentration is 100 ppm, there will be 10-19 nm and 62-91 nm segments. When the concentration is 100 ppm, the range of particles falls between 68-217 nm. Thus, it can be seen that the increase of the initial concentration of naphthalene will change the particle size of the particles generated by the discharge, and produce the trend to migrate to the large size segment. (3) BET data. The changes in the structure of the gamma -A1203 ball after the loading of the supported catalyst showed that the specific surface area and the pore volume of the total pore decreased in varying degrees. The XPS characterization results of the Ag/ gamma -A1203 showed that the Ag element was successfully loaded on the gamma -A1203 pellets by impregnation and calcined. After the plasma region, different kinds of urges were filled. The chemical agent can promote the degradation of naphthalene and enhance the removal rate of naphthalene and the selectivity of COx. The principle is to use the plasma to degrade naphthalene, and then pass the gas into the post catalyst area, use the catalyst to decompose the ozone into the living oxygen atom and further degrade the naphthalene and the inter product. The removal rate of naphthalene is as follows: Ag/ gamma -Al2O3Mn/ gamma -Al2O3 Co/ gamma -Al2O3 gamma -Al2O3, which also has a similar tendency to the effect of COx selectivity. At the same time, the catalyst can have good removal effect on both ozone and particles. The increase of temperature will enhance the effect of Ag/ gamma -A1203 catalytic oxidation naphthalene and the degradation of intermediate products. Meanwhile, COx is selected for COx. Selectivity has a promoting effect, while the 5% silver load is the best value and the best selectivity for COx.
【學(xué)位授予單位】：浙江工商大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：X51
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 薛文博;付飛;王金南;唐貴謙;雷宇;楊金田;王躍思;;中國PM_(2.5)跨區(qū)域傳輸特征數(shù)值模擬研究[J];中國環(huán)境科學(xué);2014年06期
2 劉貝貝;陳歆;彭黎旭;;河口海岸沉積物中多環(huán)芳烴的環(huán)境行為研究[J];熱帶作物學(xué)報;2013年10期
3 楊洪斌;鄒旭東;汪宏宇;劉玉徹;;大氣環(huán)境中PM_(2.5)的研究進(jìn)展與展望[J];氣象與環(huán)境學(xué)報;2012年03期
4 ;Naphthalene decomposition in a DC corona radical shower discharge[J];Journal of Zhejiang University-Science A(Applied Physics & Engineering);2011年01期
5 賀泓;余運波;李毅;吳強;張秀麗;張長斌;石曉燕;宋小萍;;Ag/Al_2O_3催化劑催化含氧烴類選擇性還原氮氧化物的基礎(chǔ)與應(yīng)用研究進(jìn)展[J];催化學(xué)報;2010年05期
6 王峰;何立明;蘭宇丹;杜宏亮;;初始溫度對O_2等離子體形成過程的影響[J];空軍工程大學(xué)學(xué)報(自然科學(xué)版);2010年02期
7 聞夢;曲振平;張曉東;李新勇;;Ag/SiO_2催化劑對CO低溫催化氧化活性[J];中國科技論文在線;2009年05期
8 謝文林;汽車車身噴漆廢氣的排放分析及處理措施[J];汽車研究與開發(fā);2005年08期
9 王麗燕,王愛杰,任南琪,杜大仲;有機廢氣(VOC)生物處理研究現(xiàn)狀與發(fā)展趨勢[J];哈爾濱工業(yè)大學(xué)學(xué)報;2004年06期
10 賀泓,張潤鐸,余運波,劉俊鋒;富氧條件下氮氧化物的選擇性催化還原 Ⅰ.Ag/Al_2O_3催化劑上C_3H_6選擇性催化還原NO的性能[J];催化學(xué)報;2003年10期
，本文編號：2141963
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