煤颗粒固定床加压富氧燃烧特性及污染物生成试验研究
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摘要
为研究煤加压富氧燃烧及其污染物生成特性,建立了加压水平管式炉富氧燃烧实验系统.以山西浑源烟煤为实验原料,探究了不同燃烧压力(0.1～0.9 MPa)和不同气氛(空气以及O_2浓度分别为21%,26%,31%,36%,41%的O_2/CO_2气氛)对煤加压富氧燃烧过程的燃烧特性以及污染物生成的影响.结果显示,与空气燃烧相比,O_2/CO_2气氛下煤燃烧时间增加;随着O_2浓度的增加,煤燃烧时间缩短;升高反应压力,煤燃烧速率增大且增幅逐渐减小;随着反应压力的提高NO_x生成量逐渐减少,O_2/CO_2气氛下NO_x生成量小于空气气氛下NO_x生成量,随着O_2浓度增加,NO_x生成量增加;压力升高导致SO_2生成量明显减少,O_2/CO_2气氛下SO_2生成量小于空气气氛下SO_2生成量,SO_2生成量随着O_2浓度增加而增多.
To investigate the combustion characteristics and the pollutant emission characteristics of coal in pressurized oxy-fuel combustion,an experimental system with pressurized horizontal tube furnace oxy-fuel combustion was established,using Shanxi Hunyuan bituminous coal as an experimental material. This paper discussed effects of different combustion pressures( 0. 1 to 0. 9 MPa) and different atmospheres( air and O_2/CO_2 atmospheres with O_2 concentrations of 21%,26%,31%,36%,and 41%) on the combustion characteristics and the pollutant emission characteristics of pressurized oxy-fuel combustion processes. The results show that compared with the air combustion,the coal combustion time in O_2/CO_2 atmosphere increases. As the concentration of O_2 rises,the coal combustion time is shorter. With higher reaction pressure,the coal burning rate is accelerated and the enhancement gradually decreases. The amount of NOx generated gradually reduces with the increase of the reaction pressure in the O_2/CO_2 atmosphere,it is smaller than that in the air atmosphere.As the O_2 concentration increases,the generation of NOx is also increased. The increment in the reaction pressure leads to an obvious decrease in the amount of SO_2 produced. In the O_2/CO_2 atmosphere,the production of SO_2 is less than that in the air atmosphere and increases with the increasing O_2 concentration.
To investigate the combustion characteristics and the pollutant emission characteristics of coal in pressurized oxy-fuel combustion,an experimental system with pressurized horizontal tube furnace oxy-fuel combustion was established,using Shanxi Hunyuan bituminous coal as an experimental material. This paper discussed effects of different combustion pressures( 0. 1 to 0. 9 MPa) and different atmospheres( air and O_2/CO_2 atmospheres with O_2 concentrations of 21%,26%,31%,36%,and 41%) on the combustion characteristics and the pollutant emission characteristics of pressurized oxy-fuel combustion processes. The results show that compared with the air combustion,the coal combustion time in O_2/CO_2 atmosphere increases. As the concentration of O_2 rises,the coal combustion time is shorter. With higher reaction pressure,the coal burning rate is accelerated and the enhancement gradually decreases. The amount of NOx generated gradually reduces with the increase of the reaction pressure in the O_2/CO_2 atmosphere,it is smaller than that in the air atmosphere.As the O_2 concentration increases,the generation of NOx is also increased. The increment in the reaction pressure leads to an obvious decrease in the amount of SO_2 produced. In the O_2/CO_2 atmosphere,the production of SO_2 is less than that in the air atmosphere and increases with the increasing O_2 concentration.
引文
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[24]王春波,岳爽,许旭斌,等.O2/CO2气氛下煤焦恒温燃烧NOx释放特性[J].煤炭学报,2018,43(1):257-264.DOI:10.13225/j.cnki.jccs.2017.4205.Wang C B,Yue S,Xu X B,et al.NOx release of char in constant temperature combustion under O2/CO2atmosphere[J].Journal of China Coal Society,2018,43(1):257-264.DOI:10.13225/j.cnki.jccs.2017.4205.(in Chinese)
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[26]Duan Y Q,Duan L B,Anthony E J,et al.Nitrogen and sulfur conversion during pressurized pyrolysis under CO2 atmosphere in fluidized bed[J].Fuel,2017,189:98-106.DOI:10.1016/j.fuel.2016.10.080.
[27]雷鸣,吕凯文,王春波,等.大同烟煤增压富氧燃烧过程中硫、氯和氟的析出特性[J].燃料化学学报,2014,42(9):1053-1059.DOI:10.3969/j.issn.0253-2409.2014.09.005.Lei M,LüK W,Wang C B,et al.Investigation on sulfur,chlorine and fluorine releasing characteristics during pressurized oxy-fuel combustion of Datong bituminous coal[J].Journal of Fuel Chemistry and Technology,2014,42(9):1053-1059.DOI:10.3969/j.issn.0253-2409.2014.09.005.(in Chinese)
[28]Chamberlain S,Reeder T,Stimpson C K,et al.Acomparison of sulfur and chlorine gas species in pulverizedcoal,air-and oxy-combustion[J].Combustion and Flame,2013,160(11):2529-2539.DOI:10.1016/j.combustflame.2013.05.008.
[29]Wang X B,Adeosun A,Yablonsky G,et al.Synergistic SOx/NOx chemistry leading to enhanced SO3and NO2 formation during pressurized oxy-combustion[J].Reaction Kinetics,Mechanisms and Catalysis,2018,123(2):313-322.DOI:10.1007/s11144-017-1327-3.
[30]董学文,王宏,刘豪,等.不同气氛下燃煤SO2的排放规律研究[J].环境科学学报,2003,23(3):322-326.DOI:10.3321/j.issn:0253-2468.2003.03.007.Dong X W,Wang H,Liu H,et al.Study on SO2emission under various atmospheres during coal combustion[J].Acta Scientiae Circumstantiae,2003,23(3):322-326.DOI:10.3321/j.issn:0253-2468.2003.03.007.(in Chinese)
[31]Zheng Z,Wang H,Li Y,et al.Comparative study on SO2 release and removal under air and oxy-fuel combustion in a fluidized bed combustor[J].Journal of Southeast University(English Edition),2015,31(2):232-237.DOI:10.3969/j.issn:1003-7985.2015.02.013.
[2]Guo J J,Liu Z H,Huang X H,et al.Experimental and numerical investigations on oxy-coal combustion in a 35MW large pilot boiler[J].Fuel,2017,187:315-327.DOI:10.1016/j.fuel.2016.09.070.
[3]Fogarasi S,Cormos C C.Assessment of coal and sawdust co-firing power generation under oxy-combustion conditions with carbon capture and storage[J].Journal of Cleaner Production,2017,142:3527-3535.DOI:10.1016/j.jclepro.2016.10.115.
[4]Bhunia S,Sadhukhan A K,Gupta P.Modelling and experimental studies on oxy-fuel combustion of coarse size coal char[J].Fuel Processing Technology,2017,158:73-84.DOI:10.1016/j.fuproc.2016.11.015.
[5]Ilbas M,Bektas A,Karyeyen S.Effect of oxy-fuel combustion on flame characteristics of low calorific value coal gases in a small burner and combustor[J].Fuel,2018,226:350-364.DOI:10.1016/j.fuel.2018.04.023.
[6]Wu F,Argyle M D,Dellenback P A,et al.Progress in O2 separation for oxy-fuel combustion-A promising way for cost-effective CO2 capture:A review[J].Progress in Energy and Combustion Science,2018,67:188-205.DOI:10.1016/j.pecs.2018.01.004.
[7]Nemitallah M A,Habib M A,Badr H M,et al.Oxyfuel combustion technology:Current status,applications,and trends[J].International Journal of Energy Research,2017,41(12):1670-1708.DOI:10.1002/er.3722.
[8]Hong J,Chaudhry G,Brisson J G,et al.Analysis of oxy-fuel combustion power cycle utilizing a pressurized coal combustor[J].Energy,2009,34(9):1332-1340.DOI:10.1016/j.energy.2009.05.015.
[9]Hong J.Techno-economic analysis of pressurized oxyfuel combustion power cycle for CO2 capture[D].Massachusetts,USA:Massachusetts Institute of Technology,2009.
[10]Soundararajan R,Gundersen T.Coal based power plants using oxy-combustion for CO2 capture:Pressurized coal combustion to reduce capture penalty[J].Applied Thermal Engineering,2013,61(1):115-122.DOI:10.1016/j.applthermaleng.2013.04.010.
[11]王卓雅,赵跃民,高淑玲.论中国燃煤污染及其防治[J].煤炭技术,2004,23(7):4-6.DOI:10.3969/j.issn.1008-8725.2004.07.002.Wang Z Y,Zhao Y M,Gao S L.Discussion on coalsmoke pollution and its prevention[J].Coal Technology,2004,23(7):4-6.DOI:10.3969/j.issn.1008-8725.2004.07.002.(in Chinese)
[12]Lei M,Huang X Z,Wang C B,et al.Investigation on SO2,NO and NO2 release characteristics of Datong bituminous coal during pressurized oxy-fuel combustion[J].Journal of Thermal Analysis and Calorimetry,2016,126(3):1067-1075.DOI:10.1007/s10973-016-5652-y.
[13]雷鸣,王春波,阎维平,等.增压富氧鼓泡床的NO生成特性[J].燃烧科学与技术,2014,20(5):377-382.DIO:10.11715/rskxjs.R201311032.Lei M,Wang C B,Yan W P,et al.NO emission characteristics of pressurized oxy-fuel bubbling fluidized bed[J].Journal of Combustion Science and Technology,2014,20(5):377-382.DIO:10.11715/rskxjs.R201311032.(in Chinese)
[14]Lasek J A,Gód K,Janusz M,et al.Pressurized oxyfuel combustion:A study of selected parameters[J].Energy&Fuels,2012,26(11):6492-6500.DOI:10.1021/ef201677f.
[15]Lasek J A,Janusz M,Zuwaa J,et al.Oxy-fuel combustion of selected solid fuels under atmospheric and elevated pressures[J].Energy,2013,62:105-112.DOI:10.1016/j.energy.2013.04.079.
[16]Duan Y Q,Duan L B,Hu H H,et al.Combustion and pollutant emission characteristics of coal in a pressurized fluidized bed under O2/CO2 atmosphere[J].Journal of Southeast University(English Edition),2015,31(2):188-193.
[17]Liu H,Zailani R,Gibbs B M.Comparisons of pulverized coal combustion in air and in mixtures of O2/CO2[J].Fuel,2005,84(7/8):833-840.DOI:10.1016/j.fuel.2004.11.018.
[18]Ying Z,Zheng X Y,Cui G M.Pressurized oxy-fuel combustion performance of pulverized coal for CO2capture[J].Applied Thermal Engineering,2016,99:411-418.DOI:10.1016/j.applthermaleng.2016.01.023.
[19]Wang C B,Lei M,Yan W P,et al.Combustion characteristics and ash formation of pulverized coal under pressurized oxy-fuel conditions[J].Energy&Fuels,2011,25(10):4333-4344.DOI:10.1021/ef200956q.
[20]刘倩,钟文琪,苏伟,等.基于热重-质谱联用的煤粉富氧燃烧动力学及污染物生成特性[J].化工学报,2018,69(1):523-530.Liu Q,Zhong W Q,Su W,et al.Oxy-coal combustion kinetics and formation characteristics of pollutants based on TG-MS analysis[J].CIESC Journal,2018,69(1):523-530.(in Chinese)
[21]车得福.煤氮热变迁与氮氧化物生成[M].西安:西安交通大学出版社,2013:14-18.
[22]李相鹏,张世红,廖新杰,等.CFB富氧燃烧中CO2对煤焦与NO还原作用的影响[J].工程热物理学报.2016,37(12):2703-2709.Li X P,Zhang S H,Liao X J,et al.Effect of CO2 on coal char-NO reduction process in CFB oxy-fuel combustion[J].Journal of Engineering Thermophysics,2016,37(12):2703-2709.(in Chinese)
[23]Zhou H,Li Y,Li N,et al.Conversions of fuel-N to NO and N2O during devolatilization and char combustion stages of a single coal particle under oxy-fuel fluidized bed conditions[J].Journal of the Energy Institute,2018:1-13.DOI:10.1016/j.joei.2018.01.001.
[24]王春波,岳爽,许旭斌,等.O2/CO2气氛下煤焦恒温燃烧NOx释放特性[J].煤炭学报,2018,43(1):257-264.DOI:10.13225/j.cnki.jccs.2017.4205.Wang C B,Yue S,Xu X B,et al.NOx release of char in constant temperature combustion under O2/CO2atmosphere[J].Journal of China Coal Society,2018,43(1):257-264.DOI:10.13225/j.cnki.jccs.2017.4205.(in Chinese)
[25]García-Labiano F,Hampartsoumian E,Williams A.Determination of sulfur release and its kinetics in rapid pyrolysis of coal[J].Fuel,1995,74(7):1072-1079.DOI:10.1016/0016-2361(95)00049-b.
[26]Duan Y Q,Duan L B,Anthony E J,et al.Nitrogen and sulfur conversion during pressurized pyrolysis under CO2 atmosphere in fluidized bed[J].Fuel,2017,189:98-106.DOI:10.1016/j.fuel.2016.10.080.
[27]雷鸣,吕凯文,王春波,等.大同烟煤增压富氧燃烧过程中硫、氯和氟的析出特性[J].燃料化学学报,2014,42(9):1053-1059.DOI:10.3969/j.issn.0253-2409.2014.09.005.Lei M,LüK W,Wang C B,et al.Investigation on sulfur,chlorine and fluorine releasing characteristics during pressurized oxy-fuel combustion of Datong bituminous coal[J].Journal of Fuel Chemistry and Technology,2014,42(9):1053-1059.DOI:10.3969/j.issn.0253-2409.2014.09.005.(in Chinese)
[28]Chamberlain S,Reeder T,Stimpson C K,et al.Acomparison of sulfur and chlorine gas species in pulverizedcoal,air-and oxy-combustion[J].Combustion and Flame,2013,160(11):2529-2539.DOI:10.1016/j.combustflame.2013.05.008.
[29]Wang X B,Adeosun A,Yablonsky G,et al.Synergistic SOx/NOx chemistry leading to enhanced SO3and NO2 formation during pressurized oxy-combustion[J].Reaction Kinetics,Mechanisms and Catalysis,2018,123(2):313-322.DOI:10.1007/s11144-017-1327-3.
[30]董学文,王宏,刘豪,等.不同气氛下燃煤SO2的排放规律研究[J].环境科学学报,2003,23(3):322-326.DOI:10.3321/j.issn:0253-2468.2003.03.007.Dong X W,Wang H,Liu H,et al.Study on SO2emission under various atmospheres during coal combustion[J].Acta Scientiae Circumstantiae,2003,23(3):322-326.DOI:10.3321/j.issn:0253-2468.2003.03.007.(in Chinese)
[31]Zheng Z,Wang H,Li Y,et al.Comparative study on SO2 release and removal under air and oxy-fuel combustion in a fluidized bed combustor[J].Journal of Southeast University(English Edition),2015,31(2):232-237.DOI:10.3969/j.issn:1003-7985.2015.02.013.