凹凸棒石(PG)负载V_2O_5催化剂脱除气态Hg~0的研究
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摘要
利用凹凸棒石(PG)负载V_2O_5制得V_2O_5/PG催化剂并将其用于脱除烟气中的Hg~0.在固定床反应器上研究了V_2O_5/PG催化剂脱除Hg~0的性能,考察了反应温度、汞浓度、空速、烟气成分等对V_2O_5/PG脱除Hg~0的影响,并利用傅里叶红外光谱、逐级化学提取和程序升温脱附实验分析了V_2O_5/PG上吸附Hg的形态.实验结果表明,V_2O_5/PG催化剂在120～210℃范围内、电厂烟气净化空速和所含汞浓度条件下具有良好的脱除Hg~0的能力.烟气成分对V_2O_5/PG脱除Hg~0的影响不同,O_2具有显著的促进作用,而SO_2和H_2O具有一定的抑制作用,NO和CO_2的作用不明显.O_2、SO_2和H_2O共同存在时,促进了Hg~0的脱除.傅里叶红外光谱、逐级化学提取和程序升温脱附实验的结果证实,V_2O_5/PG上吸附的汞存在不同形态,主要是Hg~(2+)的化合物,表明Hg~0在V_2O_5/PG上的脱除是吸附和催化氧化的共同作用,V_2O_5在V_2O_5/PG脱除Hg~0的过程中起到了关键作用.
A V_2O_5/PG catalyst, which was prepared by supporting V_2O_5 onto palygorskite(PG), was used to remove Hg~0 from flue gas in a fixed-bed reactor. The effects of temperature, Hg~0 concentration, space velocity and flue gas components on Hg~0 removal over V_2O_5/PG were studied. Furthermore, the speciation of Hg adsorbed over V_2O_5/PG catalyst was also characterized by FT-IR, sequential chemical extraction(SCE) and temperature programmed desorption(TPD) experiments. The results showed that V_2O_5/PG catalyst had a high Hg~0 removal capability in the temperature range of 120～210 ℃ within a space velocity and the Hg~0 concentration in flue gas of coal combustion power plant. O_2 showed a promotion effect on Hg~0 removal over V_2O_5/PG while SO_2 and H_2O showed an inhibition effect, NO and CO_2 showed no obvious effect. The co-effect of O_2, SO_2 and H_2O promoted Hg~0 removal by V_2O_5/PG. The results of FT-IR, SCE and TPD showed that there were different speciation of Hg over V_2O_5/PG and the main form was Hg~(2+) compounds. These confirmed that Hg~0 removal over V_2O_5/PG was the co-effect of adsorption and oxidation, in which the catalytic oxidation activity of V_2O_5 played a critical role, i.e. oxidizing Hg~0 to form Hg~(2+) compound.
A V_2O_5/PG catalyst, which was prepared by supporting V_2O_5 onto palygorskite(PG), was used to remove Hg~0 from flue gas in a fixed-bed reactor. The effects of temperature, Hg~0 concentration, space velocity and flue gas components on Hg~0 removal over V_2O_5/PG were studied. Furthermore, the speciation of Hg adsorbed over V_2O_5/PG catalyst was also characterized by FT-IR, sequential chemical extraction(SCE) and temperature programmed desorption(TPD) experiments. The results showed that V_2O_5/PG catalyst had a high Hg~0 removal capability in the temperature range of 120～210 ℃ within a space velocity and the Hg~0 concentration in flue gas of coal combustion power plant. O_2 showed a promotion effect on Hg~0 removal over V_2O_5/PG while SO_2 and H_2O showed an inhibition effect, NO and CO_2 showed no obvious effect. The co-effect of O_2, SO_2 and H_2O promoted Hg~0 removal by V_2O_5/PG. The results of FT-IR, SCE and TPD showed that there were different speciation of Hg over V_2O_5/PG and the main form was Hg~(2+) compounds. These confirmed that Hg~0 removal over V_2O_5/PG was the co-effect of adsorption and oxidation, in which the catalytic oxidation activity of V_2O_5 played a critical role, i.e. oxidizing Hg~0 to form Hg~(2+) compound.
引文
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王钧伟,杨建丽,刘振宇.2012.活性焦负载MnO2对气态Hg0的吸附脱除研究[J].环境科学学报,32(9):2261-2266
王钧伟,张庆平,沈园园,等.2017.凹凸棒石负载CuO催化剂脱除气态Hg0[J].环境化学,36(5):1097-1103
Wang S X,Zhang L,Wang L,et al.2014.A review of atmospheric mercury emissions,pollution and control in China[J].Frontiers of Environmental Science & Engineering,8(5):631-649
Yang J P,Zhao Y C,Ma S M,et al.2016.Mercury removal by magnetic biochar derived from simultaneous activation and magnetization of sawdust[J].Environmental Science & Technology,50:12040-12047
Zhang B,Xu P,Qiu Y,et al.2015.Increasing oxygen functional groups of activated carbon with non-thermal plasma to enhance mercury removal efficiency for flue gases[J].Chemical Engineering Journal,263:1-8
Zhang X N,Li C T,Zhao L K,et al.2015.Simultaneous removal of elemental mercury and NO from flue gas by V2O5-CeO2/TiO2 catalysts[J].Applied Surface Science,347:392-400
Zhao B,Liu X W,Zhou Z J,et al.2015.Mercury oxidized by V2O5-MoO3/TiO2 under multiple components flue gas:An actual coal-fired power plant test and a laboratory experiment[J].Fuel Processing Technology,134:198-204
Zhao B,Yi H H,Tang X L,et al.2016.Copper modified activated coke for mercury removal from coal-fired flue gas[J].Chemical Engineering Journal,286:585-593
Zhou W,Gilles E,Abu R,et al.2010.Prediction of activated carbon injection performance for mercury capture in a full-scale coal-fired boiler[J].Industrial & Engineering Chemistry Research,49:3603-3610
Zhou Z J,Liu X W,Zhao B,et al.2015.Effects of existing energy saving and air pollution control devices on mercury removal in coal-fired power plants[J].Fuel Processing Technology,131:99-108
Zhu C Y,Tian H Z,Cheng K,et al.2015.Potentials of whole process control of heavy metals emissions from coal-fired power plants in China[J].Journal of Cleaner Production,114:343-351
Cao Y,Chen B,Wu J,et al.2007.Study of mercury oxidation by a selective catalytic reduction catalyst in a pilot-scale slipstream reactor at a utility boiler burning bituminous coal[J].Energy Fuels,21:145-156
Chen Y,Guo X,Wu F,et al.2018.Experimental and theoretical studies for the mechanism of mercury oxidation over chlorine and cupric impregnated activated carbon[J].Applied Surface Science,458:790-799
Chi G L,Shen B X,Yu R R,et al.2017.Simultaneous removal of NO and Hg0 over Ce-Cu modified V2O5/TiO2 based commercial SCR catalysts[J].Journal of Hazardous Materials,330:83-92
Colin B W,Chad T,William F,et al.2012.Preparation and characterization of high efficiency modified activated carbon for the capture of mercury from flue gas in coal-fired power plants[J].Fuel Processing Technology,97:107-117
Ding F,Zhao Y C,Mi L L,et al.2012.Removal of gas-phase elemental mercury in flue gas by inorganic chemically promoted natural mineral sorbents[J].Industrial & Engineering Chemistry Research,51(2):3039-3047
高翔云,高孝礼,汪建明.2016.盱眙凹凸棒石黏土的中红外和近红外光谱特征研究与应用[J].江苏科技信息,3 (9):51-54
Guo S Q,Yang J L,Liu Z Y,et al.2009.Behavior of mercury release during thermal decomposition of coals[J].Korean Journal of Chemical Engineering,26(2):560-563
He C,Shen B X,Li F K.2016.Effects of flue gas components on removal of elemental mercury over Ce-MnOx/Ti-PILCs[J].Journal of Hazardous Materials,304:10-17
He S,Zhou J,Zhu Y,et al.2009.Mercury oxidation over a vanadia-based selective catalytic reduction catalyst[J].Energy Fuels,23:253-259
Hu C X,Zhou J S,Luo Z Y,et al.2011.Oxidative adsorption of elemental mercury by activated carbon in simulated coal-fired flue gas[J].Energy Fuels,25:154-158
Jones A,Hoffmann J,Smith D,et al.2007.DOE/NETL′s phase II mercury control technology field testing program:Preliminary economic analysis of activated carbon injection[J].Environmental Science & Technology,41:1365-1371
Li B,Wang H L,Xu Y Y,et al.2017.Study on mercury oxidation by SCR catalyst in coal-fired power plant[J].Energy Procedia,141:339-344
李金虎,张先龙,陈天虎,等.2010.凹凸棒石负载锰氧化物低温选择性催化还原催化剂的表征及对氨的吸脱附[J].催化学报,31(4):454-460
Li Y N,Duan Y F,Wang H,et al.2017.Effects of acidic gases on mercury adsorption by activated carbon in simulated oxy-fuel combustion flue gas[J].Energy Fuels,31:9745-9751
Liu F F,Zhang J Y,Zhao Y C,et al.2014.Mercury removal from flue gas by metal oxide-loaded attapulgite mineral sorbent[J].Journal of Combustion Science and Technology,20(6):553-557
Luo S P,Zhou W T,Xie A J,et al.2016.Effect of MnO2 polymorphs structure on the selective catalytic reduction of NOx with NH3 over TiO2-Palygorskite[J].Chemical Engineering Journal,286:291-299
Rumayor M,López-Antón M A.2015.Temperature programmed desorption as a tool for the identification of mercury fate in wet-desulphurization systems[J].Fuel,148:98-103
Suárez M,García-Romero E.2016.FTIR spectroscopic study of palygorskite:Influence of the composition of the octahedral sheet[J].Applied Clay Science,31:154-163
孙阳昭,陈扬,蓝虹,等.2013.中国汞污染的来源、成因及控制技术路径分析[J].环境化学,32(6):937-942
王钧伟,陈培,刘瑞卿,等.2014.粉煤灰负载Fe2O3脱除气态单质汞的试验研究[J].环境科学学报,34(12):3152-3157
Wang J W,Shen Y Y,Dong Y J,et al.2016.Oxidation and adsorption of gas-phase Hg0 over a V2O5/AC catalyst[J].RSC Advances,6:77553-77557
Wang J,Wang W H,Xu W,et al.2011.Mercury removals by existing pollutants control devices of four coal-fired power plants in China[J].Journal of Environmental Sciences,23(11):1839-1844
Wang J W,Yang J L,Liu Z Y.2010.Gas-phase elemental mercury capture by a V2O5/AC catalyst[J].Fuel Processing Technology,91(6):676-680
王钧伟,杨建丽,刘振宇.2012.活性焦负载MnO2对气态Hg0的吸附脱除研究[J].环境科学学报,32(9):2261-2266
王钧伟,张庆平,沈园园,等.2017.凹凸棒石负载CuO催化剂脱除气态Hg0[J].环境化学,36(5):1097-1103
Wang S X,Zhang L,Wang L,et al.2014.A review of atmospheric mercury emissions,pollution and control in China[J].Frontiers of Environmental Science & Engineering,8(5):631-649
Yang J P,Zhao Y C,Ma S M,et al.2016.Mercury removal by magnetic biochar derived from simultaneous activation and magnetization of sawdust[J].Environmental Science & Technology,50:12040-12047
Zhang B,Xu P,Qiu Y,et al.2015.Increasing oxygen functional groups of activated carbon with non-thermal plasma to enhance mercury removal efficiency for flue gases[J].Chemical Engineering Journal,263:1-8
Zhang X N,Li C T,Zhao L K,et al.2015.Simultaneous removal of elemental mercury and NO from flue gas by V2O5-CeO2/TiO2 catalysts[J].Applied Surface Science,347:392-400
Zhao B,Liu X W,Zhou Z J,et al.2015.Mercury oxidized by V2O5-MoO3/TiO2 under multiple components flue gas:An actual coal-fired power plant test and a laboratory experiment[J].Fuel Processing Technology,134:198-204
Zhao B,Yi H H,Tang X L,et al.2016.Copper modified activated coke for mercury removal from coal-fired flue gas[J].Chemical Engineering Journal,286:585-593
Zhou W,Gilles E,Abu R,et al.2010.Prediction of activated carbon injection performance for mercury capture in a full-scale coal-fired boiler[J].Industrial & Engineering Chemistry Research,49:3603-3610
Zhou Z J,Liu X W,Zhao B,et al.2015.Effects of existing energy saving and air pollution control devices on mercury removal in coal-fired power plants[J].Fuel Processing Technology,131:99-108
Zhu C Y,Tian H Z,Cheng K,et al.2015.Potentials of whole process control of heavy metals emissions from coal-fired power plants in China[J].Journal of Cleaner Production,114:343-351