高压脉冲放电协同LaMn_(1-x)Fe_xO_3钙钛矿型催化剂去除NO_x
|
摘要
高压脉冲放电协同催化剂技术是目前最具有前景的去除NO_x的方法之一,本文以氮氧化物为处理对象,通过脉冲放电协同LaMn_(1-x)Fe_xO_3钙钛矿型催化剂去除NO_x.采用柠檬酸-EDTA溶胶凝胶法制备LaMnO_3钙钛矿催化剂,对该催化剂掺杂Fe元素,改变催化剂制备时的焙烧温度,探究催化剂协同脉冲放电在不同反应温度、催化剂投加量等因素下对NO转化、NO_2生成和NO_x的去除效果的影响,从而达到提高氮氧化物的去除率、降低能耗等目的.同时结合XRD、SEM、BET等表征手段对催化剂进行表征.结果表明,在催化剂LaMn_(1-x)Fe_xO_3中,随着Fe掺杂比的增加,NO转化率出现先增大后逐渐减小的趋势;随着催化剂的焙烧温度增加,NO转化率出现逐渐减小的趋势;随着催化剂投加量的增加,NO_x去除率不断增大后趋于稳定.在放电频率为30 Hz、脉冲电压为30 kV、Fe的掺杂比为0.3、焙烧温度为700℃、投加量为1.6 g、反应温度为300℃的条件下,NO_x的去除率为62.15%.
High-voltage pulsed discharge synergistic catalyst technology is one of the most promising NO_x removal methods at present. The object of treatment in this paper was NO_x, which was removed by a pulsed discharge in conjunction with a perovskite-type catalyst. A citric acid-EDTA Sol-Gel method was employed to prepare LaMnO_3 perovskite catalyst. By mixing Fe with the catalyst and by changing the calcination temperatures in the process of catalyst preparation, the effects of the catalyst-co-pulsed discharge on NO conversion, NO_2 generation, and NO_x removal efficiency under different sets of conditions such as reaction temperatures, catalyst doping amount were analyzed. XRD and SEM were used to characterize the catalysts. The results showed that with increasing amount of Fe added in the catalyst LaMn_(1-x)Fe_xO_3, the NO conversion first increased and then gradually went down. With the increase of calcination temperature, the NO conversion rate gradually decreased. With increasing dosage of the catalyst, the NO_x removal rate increased and then stabilized. When setting discharge frequency to be 30 Hz, pulse voltage 30 kV, Fe doping amount 0.3, calcination temperature 700 ℃, dosage of catalyst 1.6 g, and reaction temperature 300 ℃, the highest NO_x removal rate of 62.15% was reached.
High-voltage pulsed discharge synergistic catalyst technology is one of the most promising NO_x removal methods at present. The object of treatment in this paper was NO_x, which was removed by a pulsed discharge in conjunction with a perovskite-type catalyst. A citric acid-EDTA Sol-Gel method was employed to prepare LaMnO_3 perovskite catalyst. By mixing Fe with the catalyst and by changing the calcination temperatures in the process of catalyst preparation, the effects of the catalyst-co-pulsed discharge on NO conversion, NO_2 generation, and NO_x removal efficiency under different sets of conditions such as reaction temperatures, catalyst doping amount were analyzed. XRD and SEM were used to characterize the catalysts. The results showed that with increasing amount of Fe added in the catalyst LaMn_(1-x)Fe_xO_3, the NO conversion first increased and then gradually went down. With the increase of calcination temperature, the NO conversion rate gradually decreased. With increasing dosage of the catalyst, the NO_x removal rate increased and then stabilized. When setting discharge frequency to be 30 Hz, pulse voltage 30 kV, Fe doping amount 0.3, calcination temperature 700 ℃, dosage of catalyst 1.6 g, and reaction temperature 300 ℃, the highest NO_x removal rate of 62.15% was reached.
引文
[1] 林晓芬,张军,尹艳山,等.烟气脱硫脱氮技术综述[J].能源环境保护,2014,28(1):1-4.LIN X F,ZHANG J,YIN Y S,et al.A review of flue gas desulfurization and denitrification technology [J].Energy Environmental Protection,2014,28(1):1-4(in Chinese).
[2] 黄诗坚.NOx的危害及其排放控制[J].能源环境保护,2004,20(1):24-25.HUANG S J.The harm of NOx and its emission control [J].Power Environmental Protection,2004,20(1):24-25(in Chinese).
[3] 刘育松,高凤雨,唐晓龙,等.制备条件对锰氧化物SCR 脱硝性能的影响[J].环境工程学报,2016,10(1):295-300.LIU Y S,GAO F Y,TANG X L,et al.Effect of preparation conditions on the De-NOx performance of manganese oxide SCR[J].Journal of Environmental Engineering,2016,10(1):295-300(in Chinese).
[4] LI J,CHANG H,MA L,et al.Low-temperature selective catalytic reduction of NOx with NH3 over metal oxide and zeolite catalysts:A review [J].Catalysis Today,2011,175(1):147-156.
[5] 陈冬林,曾稀,盘思伟,等.钒基活化液增活V2O5 -WO3 -MoO3/TiO2催化剂的实验研究[J].环境工程学报,2015,9(2):847-854.CHEN D L,ZENG X,PAN S W,et al.Experimental study on activation of V2O5-WO3 -MoO3/TiO2 catalysts with vanadium-based activation solution[J].Journal of Environmental Engineering,2015,9(2):843-854(in Chinese).
[6] XIAO X,SHENG Z,YANG L,et al.Low-temperature selective catalytic reduction of NOx with NH3 over manganese and cerium oxides composite with graphene prepared by hydrothermal method[J].Catalysis Science & Technology,2015,6(5):1507-1514.
[7] ZHANG Y P,WANG L F.Promotional roles of ZrO2 and WO3 in V2O5- WO3/TiO2- ZrO2 catalysts for NOx reduction by NH3:Catalytic performance,morphology,and reaction mechanism[J].Chinese Journal of Catalysis,2016,37(11):1918-1930.
[8] NAKATSUJI T,MIYAMOTO A.Removal technology for nitrogen oxides and sulfur oxides from exhaust gases[J].Catalysis Today,1991,10(1):21-31.
[9] LI X G,DONG Y H,XIAN H.De-NOx in alternative lean/rich atmospheres on La1-xSrxCoO3 perovskite[J].Energy & Environmental Science,2011,1:3351-3354.
[10] IWAMOTO M,HAMARDE H,CATAL.Today,removal of nitrogen monoxide from exhaust gases through novel catalytic processes[J].Catalysis Today,1991,10(1):57-71.
[11] HELD W,K?NIG A,RICHTER T,et al.Catalytic NOx reduction in net oxidizing exhaust gas[J].Emissions,1990,99:209-216..
[12] TUREK W,PLIS A,COSTA P D,et al.Investigation of oxide catalysts activity in the NOx,neutralisation with organic reductants[J].Applied Surface Science,2010,256(17):5572-5575.
[13] BETHKE K A,ALT D,KUNG M C.NO reduction by hydrocarbons in an oxidizing atmosphere over transition metal-zirconium mixed oxides[J].Catalysis Letters,1994,25(1-2):37-48.
[14] ZHANG X K,WALTERS A B,VANNICE M A.NO Adsorption,decomposition,and reduction by methane over rare earth oxides[J].Journal of Catalysis,1995,155(2):290-302.
[15] 孙志强,王虹,任晓光.La- Na- Co- Mn- O系钙钛矿型催化剂同时去除柴油机碳颗粒和NOx性能的研究[J].环境科学保护,2007,33(4):4-7.SUN Z Q,WANG H,REN X G.Investigationof catalytic activity of La- Na- Co- Mn- O perovskite- type oxides for simultaneous removal of diesel soot particulatesand NOx[J].Environmental Science Protection,2007,33(4):4-7(in Chinese).
[16] 彭小圣,林赫,黄霞,等.采用钙钛矿型催化剂 (La0.8K0.2Cu0.05Mn0.95O3)同时催化去除NOx和碳烟的研究[J].环境科学学报,2006,26(5):779-784.PENG X S,LIN H,HUANG X,et al.Investigation of catalytic removal of NOx and soot over La0.8K0.2Cu0.05Mn0.95O3[J].Journal of Environmental Science,2006,26(5):779-784(in Chinese).
[17] 白敏菂,毛首蕾,朱玉鹏,等.O2+、O3同时脱硫脱硝实验[J].中国环境科学,2014,34(2):324-330.BAI M D,MAO S L,ZHU Y P,et al.Simultaneous desulfurization and denitrification of O2+ and O3[J].China Environmental Science,2014,34(2):324-330(in Chinese).
[18] 董冰岩,聂亚林,宿雅威,等.双极性高压脉冲介质阻挡放电降解甲醛及臭氧生成质量浓度控制[J].高电压技术,2016,42(5):1373-1378.DONG B Y,NIE Y L,SU Y W,et al.The degradation of formaldehyde and ozone formation by concentration control of bipolar high voltage pulse dielectric barrier discharge [J].High Voltage Engineering,2016,42(5):1373-1378(in Chinese).
[19] 王艳辉,张瑞丽,孙继忠,等.脉冲介质阻挡放电脱除N2/NO体系中NO的模拟研究[J].高电压技术,2016,42(2):405-413.WANG Y H,ZHANG R L,SUN J Z,et al.Simulation study on removal of NO in N2/NO system by pulse dielectric barrier discharge[J].High Voltage Engineering,2016,42(2):405-413(in Chinese).
[20] 王飞飞,李树然,闫克平.电弧放电产生NOx及其对亚硫酸铵的氧化[J].环境工程学报,2015,9(1):281-287.WANG F F,LI S R,YAN K P.Generation of NOx by arc discharge and its oxidation of ammonium sulfite [J].Journal of Environmental Engineering,2015,9(1):281-287(in Chinese).
[21] PENETRANTE B M,BRUSASCO R M,MERRITT B T,et al.Plasma-assisted catalytic reduction of NOx [R].DTIC Document,1998.
[2] 黄诗坚.NOx的危害及其排放控制[J].能源环境保护,2004,20(1):24-25.HUANG S J.The harm of NOx and its emission control [J].Power Environmental Protection,2004,20(1):24-25(in Chinese).
[3] 刘育松,高凤雨,唐晓龙,等.制备条件对锰氧化物SCR 脱硝性能的影响[J].环境工程学报,2016,10(1):295-300.LIU Y S,GAO F Y,TANG X L,et al.Effect of preparation conditions on the De-NOx performance of manganese oxide SCR[J].Journal of Environmental Engineering,2016,10(1):295-300(in Chinese).
[4] LI J,CHANG H,MA L,et al.Low-temperature selective catalytic reduction of NOx with NH3 over metal oxide and zeolite catalysts:A review [J].Catalysis Today,2011,175(1):147-156.
[5] 陈冬林,曾稀,盘思伟,等.钒基活化液增活V2O5 -WO3 -MoO3/TiO2催化剂的实验研究[J].环境工程学报,2015,9(2):847-854.CHEN D L,ZENG X,PAN S W,et al.Experimental study on activation of V2O5-WO3 -MoO3/TiO2 catalysts with vanadium-based activation solution[J].Journal of Environmental Engineering,2015,9(2):843-854(in Chinese).
[6] XIAO X,SHENG Z,YANG L,et al.Low-temperature selective catalytic reduction of NOx with NH3 over manganese and cerium oxides composite with graphene prepared by hydrothermal method[J].Catalysis Science & Technology,2015,6(5):1507-1514.
[7] ZHANG Y P,WANG L F.Promotional roles of ZrO2 and WO3 in V2O5- WO3/TiO2- ZrO2 catalysts for NOx reduction by NH3:Catalytic performance,morphology,and reaction mechanism[J].Chinese Journal of Catalysis,2016,37(11):1918-1930.
[8] NAKATSUJI T,MIYAMOTO A.Removal technology for nitrogen oxides and sulfur oxides from exhaust gases[J].Catalysis Today,1991,10(1):21-31.
[9] LI X G,DONG Y H,XIAN H.De-NOx in alternative lean/rich atmospheres on La1-xSrxCoO3 perovskite[J].Energy & Environmental Science,2011,1:3351-3354.
[10] IWAMOTO M,HAMARDE H,CATAL.Today,removal of nitrogen monoxide from exhaust gases through novel catalytic processes[J].Catalysis Today,1991,10(1):57-71.
[11] HELD W,K?NIG A,RICHTER T,et al.Catalytic NOx reduction in net oxidizing exhaust gas[J].Emissions,1990,99:209-216..
[12] TUREK W,PLIS A,COSTA P D,et al.Investigation of oxide catalysts activity in the NOx,neutralisation with organic reductants[J].Applied Surface Science,2010,256(17):5572-5575.
[13] BETHKE K A,ALT D,KUNG M C.NO reduction by hydrocarbons in an oxidizing atmosphere over transition metal-zirconium mixed oxides[J].Catalysis Letters,1994,25(1-2):37-48.
[14] ZHANG X K,WALTERS A B,VANNICE M A.NO Adsorption,decomposition,and reduction by methane over rare earth oxides[J].Journal of Catalysis,1995,155(2):290-302.
[15] 孙志强,王虹,任晓光.La- Na- Co- Mn- O系钙钛矿型催化剂同时去除柴油机碳颗粒和NOx性能的研究[J].环境科学保护,2007,33(4):4-7.SUN Z Q,WANG H,REN X G.Investigationof catalytic activity of La- Na- Co- Mn- O perovskite- type oxides for simultaneous removal of diesel soot particulatesand NOx[J].Environmental Science Protection,2007,33(4):4-7(in Chinese).
[16] 彭小圣,林赫,黄霞,等.采用钙钛矿型催化剂 (La0.8K0.2Cu0.05Mn0.95O3)同时催化去除NOx和碳烟的研究[J].环境科学学报,2006,26(5):779-784.PENG X S,LIN H,HUANG X,et al.Investigation of catalytic removal of NOx and soot over La0.8K0.2Cu0.05Mn0.95O3[J].Journal of Environmental Science,2006,26(5):779-784(in Chinese).
[17] 白敏菂,毛首蕾,朱玉鹏,等.O2+、O3同时脱硫脱硝实验[J].中国环境科学,2014,34(2):324-330.BAI M D,MAO S L,ZHU Y P,et al.Simultaneous desulfurization and denitrification of O2+ and O3[J].China Environmental Science,2014,34(2):324-330(in Chinese).
[18] 董冰岩,聂亚林,宿雅威,等.双极性高压脉冲介质阻挡放电降解甲醛及臭氧生成质量浓度控制[J].高电压技术,2016,42(5):1373-1378.DONG B Y,NIE Y L,SU Y W,et al.The degradation of formaldehyde and ozone formation by concentration control of bipolar high voltage pulse dielectric barrier discharge [J].High Voltage Engineering,2016,42(5):1373-1378(in Chinese).
[19] 王艳辉,张瑞丽,孙继忠,等.脉冲介质阻挡放电脱除N2/NO体系中NO的模拟研究[J].高电压技术,2016,42(2):405-413.WANG Y H,ZHANG R L,SUN J Z,et al.Simulation study on removal of NO in N2/NO system by pulse dielectric barrier discharge[J].High Voltage Engineering,2016,42(2):405-413(in Chinese).
[20] 王飞飞,李树然,闫克平.电弧放电产生NOx及其对亚硫酸铵的氧化[J].环境工程学报,2015,9(1):281-287.WANG F F,LI S R,YAN K P.Generation of NOx by arc discharge and its oxidation of ammonium sulfite [J].Journal of Environmental Engineering,2015,9(1):281-287(in Chinese).
[21] PENETRANTE B M,BRUSASCO R M,MERRITT B T,et al.Plasma-assisted catalytic reduction of NOx [R].DTIC Document,1998.