富氧条件下贫煤燃烧过程中煤焦结构的变化规律
|
摘要
为研究富氧燃烧后煤焦的孔隙结构及其在燃烧过程中的变化情况,选取贵阳贫煤作为研究对象,利用红外光谱仪、比表面积及孔隙度分析仪分别分析了焦炭样品官能团变化和表面孔隙分布,讨论了不同富氧燃烧条件和不同燃烧阶段对官能团和孔隙结构的影响。研究结果表明,在氧气浓度不变的情况下,随着试验温度的升高,羟基数量明显减少;在同一比例的富氧气氛下,随着反应温度的升高,焦炭吸附等温线由Ⅱ型向Ⅲ型转变;氧气浓度为40%的气氛条件下,在400℃时焦炭表面主要是两端都开放的微孔,900℃时由于部分孔道坍塌,形成了大量一端封闭的孔隙。
To study the coke pore structure and changes in the process,Guiyang lean coal was selected as the research object,samples were made under two different oxygen-enriched atmospheres and three different combustion reaction temperatures.The functional group changes and surface pore distribution of coke samples were analyzed by the FTIR and specific surface area and porosity analyzer respectively.The effects of oxygen-enriched combustion conditions on functional groups and pore structures and the characteristics of combustion products at different reaction temperatures in oxygen-enriched combustion atmospheres were discussed.The results show that the number of hydroxyl groups decreases with the increase of the experimental temperature.In the same ratio of oxygen-enriched atmosphere,with the increase of reaction temperature,coke adsorption isotherm changes from typeⅡtotypeⅢ.With the progress of the reaction,the number of micropores and large pores in coal samples changesalot.When the oxygen concentration is 40%,many micropores which areopen at both ends are on the coke surface,a large number of closed pores at one end formed due to the collapse of part of the channels at 900℃.
To study the coke pore structure and changes in the process,Guiyang lean coal was selected as the research object,samples were made under two different oxygen-enriched atmospheres and three different combustion reaction temperatures.The functional group changes and surface pore distribution of coke samples were analyzed by the FTIR and specific surface area and porosity analyzer respectively.The effects of oxygen-enriched combustion conditions on functional groups and pore structures and the characteristics of combustion products at different reaction temperatures in oxygen-enriched combustion atmospheres were discussed.The results show that the number of hydroxyl groups decreases with the increase of the experimental temperature.In the same ratio of oxygen-enriched atmosphere,with the increase of reaction temperature,coke adsorption isotherm changes from typeⅡtotypeⅢ.With the progress of the reaction,the number of micropores and large pores in coal samples changesalot.When the oxygen concentration is 40%,many micropores which areopen at both ends are on the coke surface,a large number of closed pores at one end formed due to the collapse of part of the channels at 900℃.
引文
[1]鄢晓忠,邱靖,尹艳山,等.褐煤中官能团对其燃烧特性的影响[J].煤炭科学技术,2016,44(4):169-174.YAN Xiao-zhong,QIU Jing,YIN Yan-shan,et al.The effect of functional groups in lignite on its combustion characteristics[J].Coal Science and Technology,2016,44(4):169-174.
[2]韩峰,张衍国,蒙爱红,等.云南褐煤结构的FTIR分析[J].煤炭学报,2014,39(11):2293-2299.HAN Feng,ZHANG Yan-guo,MENG Ai-hong,et al.FTIR analysis of lignite structure in Yunnan[J].Journal of China Coal Society,2014,39(11):2293-2299.
[3]王海燕,樊少武,姚海飞.2种不同变质程度煤表面化学结构红外光谱分析[J].煤矿安全,2018,49(1):194-197.WANG Hai-yan,FAN Shao-wu,YAO Hai-fei.Infrared spectroscopy analysis of chemical structure of coal with two different metamorphic degrees[J].Coal Mine Safety,2018,49(1):194-197.
[4]Sobkowiak M,Reisser E,Given P,et al.Determination of aromatic and aliphatic CH groups in coal by FT-IR:1.Studies of coal extracts[J].Fuel,1984(9):1245.
[5]涂湘巍,黄胜,曹琴,等.煤焦孔隙结构的表征及分析方法的构建[J].华东理工大学学报:自然科学版,2015,41(5):611-616.TU Xiang-yu,HUANG Sheng,GAO Qin,et al.Characterization of coal char pore structure and construction of analytical methods[J].Journal of East China University of Science and Technology:Natural Science Edition,2015,41(5):611-616.
[6]高晨,鄢晓忠,许龙泉.富氧条件下温度对煤焦结构中官能团和孔隙结构变化影响的实验研究[J].煤炭技术,2018,37(7):301-304.GAO Chen,YAN Xiao-zhong,XU Long-quan.Experimental study on the effect of temperature on the change of functional groups and pore structure in coal char structure under oxygen-rich conditions[J].Coal Technology,2018,37(7):301-304.
[7]张辉,钟志光,张海峰.近红外光谱技术在煤质分析中的应用及展望[J].洁净煤技术,2015,21(6):40-42,51.ZHAGN Hui,ZHONG Zhi-guang,ZHANG Haifeng.Application and prospect of near infrared spectroscopy in coal quality analysis[J].Clean Coal Technology,2015,21(6):40-42,51.
[8]高英,袁巧霞,陈汉平,等.水葫芦水热碳化过程中焦炭物化结构演变特性[J].华中科技大学学报:自然科学版,2015,43(6):116-121.GAO Ying,YUAN Qiao-xia,CHEN Han-ping,et al.Evolution characteristics of coke physicochemical structure during hydrothermal carbonization of water hyacinth[J].Journal of Huazhong University of Science and Technology:Natural Science,2015,43(6):116-121.
[9]陈向军,刘军,王林,等.不同变质程度煤的孔径分布及其对吸附常数的影响[J].煤炭学报,2013,38(2):294-300.CHEN Xiang-jun,LIU Jun,Wang Lin,et al.Pore size distribution of coal with different metamorphic degrees and its influence on adsorption constant[J].Journal of the Coal Society,2013,38(2):294-300.
[10]高旭.基于低温氮吸附法的焦煤孔隙表面分形特征[J].煤矿安全,2014,45(12):20-23.GAO Xu.Fractal characteristics of coking coal pore surface based on low temperature nitrogen adsorption method[J].Coal Mine Safety,2014,45(12):20-23.
[11]严继民,张启元.吸附与凝聚固体的表面与孔[M].北京:科学出版社,1979.YAN Ji-min,ZHAGN Qi-yuan.Adsorption and condensation of solid surfaces and pores[M].Beijing:Science Press,1979.
[12]孟召平,刘珊珊,王保玉,等.不同煤体结构煤的吸附性能及其孔隙结构特征[J].煤炭学报,2015,40(8):1865-1870.MENG Zhao-ping,LIU Shan-shan,WANG Bao-yu,et al.Adsorption properties and pore structure characteristics of different coal structure coals[J].Journal of China Coal Society,2015,40(8):1865-1870.
[2]韩峰,张衍国,蒙爱红,等.云南褐煤结构的FTIR分析[J].煤炭学报,2014,39(11):2293-2299.HAN Feng,ZHANG Yan-guo,MENG Ai-hong,et al.FTIR analysis of lignite structure in Yunnan[J].Journal of China Coal Society,2014,39(11):2293-2299.
[3]王海燕,樊少武,姚海飞.2种不同变质程度煤表面化学结构红外光谱分析[J].煤矿安全,2018,49(1):194-197.WANG Hai-yan,FAN Shao-wu,YAO Hai-fei.Infrared spectroscopy analysis of chemical structure of coal with two different metamorphic degrees[J].Coal Mine Safety,2018,49(1):194-197.
[4]Sobkowiak M,Reisser E,Given P,et al.Determination of aromatic and aliphatic CH groups in coal by FT-IR:1.Studies of coal extracts[J].Fuel,1984(9):1245.
[5]涂湘巍,黄胜,曹琴,等.煤焦孔隙结构的表征及分析方法的构建[J].华东理工大学学报:自然科学版,2015,41(5):611-616.TU Xiang-yu,HUANG Sheng,GAO Qin,et al.Characterization of coal char pore structure and construction of analytical methods[J].Journal of East China University of Science and Technology:Natural Science Edition,2015,41(5):611-616.
[6]高晨,鄢晓忠,许龙泉.富氧条件下温度对煤焦结构中官能团和孔隙结构变化影响的实验研究[J].煤炭技术,2018,37(7):301-304.GAO Chen,YAN Xiao-zhong,XU Long-quan.Experimental study on the effect of temperature on the change of functional groups and pore structure in coal char structure under oxygen-rich conditions[J].Coal Technology,2018,37(7):301-304.
[7]张辉,钟志光,张海峰.近红外光谱技术在煤质分析中的应用及展望[J].洁净煤技术,2015,21(6):40-42,51.ZHAGN Hui,ZHONG Zhi-guang,ZHANG Haifeng.Application and prospect of near infrared spectroscopy in coal quality analysis[J].Clean Coal Technology,2015,21(6):40-42,51.
[8]高英,袁巧霞,陈汉平,等.水葫芦水热碳化过程中焦炭物化结构演变特性[J].华中科技大学学报:自然科学版,2015,43(6):116-121.GAO Ying,YUAN Qiao-xia,CHEN Han-ping,et al.Evolution characteristics of coke physicochemical structure during hydrothermal carbonization of water hyacinth[J].Journal of Huazhong University of Science and Technology:Natural Science,2015,43(6):116-121.
[9]陈向军,刘军,王林,等.不同变质程度煤的孔径分布及其对吸附常数的影响[J].煤炭学报,2013,38(2):294-300.CHEN Xiang-jun,LIU Jun,Wang Lin,et al.Pore size distribution of coal with different metamorphic degrees and its influence on adsorption constant[J].Journal of the Coal Society,2013,38(2):294-300.
[10]高旭.基于低温氮吸附法的焦煤孔隙表面分形特征[J].煤矿安全,2014,45(12):20-23.GAO Xu.Fractal characteristics of coking coal pore surface based on low temperature nitrogen adsorption method[J].Coal Mine Safety,2014,45(12):20-23.
[11]严继民,张启元.吸附与凝聚固体的表面与孔[M].北京:科学出版社,1979.YAN Ji-min,ZHAGN Qi-yuan.Adsorption and condensation of solid surfaces and pores[M].Beijing:Science Press,1979.
[12]孟召平,刘珊珊,王保玉,等.不同煤体结构煤的吸附性能及其孔隙结构特征[J].煤炭学报,2015,40(8):1865-1870.MENG Zhao-ping,LIU Shan-shan,WANG Bao-yu,et al.Adsorption properties and pore structure characteristics of different coal structure coals[J].Journal of China Coal Society,2015,40(8):1865-1870.