典型农作物秸秆组成及燃烧动力学分析
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摘要
为了探讨我国典型区域典型农作物秸秆的组成及燃烧特性,在典型农作物种植区(河北省和吉林省)选择了三种典型秸秆(小麦秸秆、水稻秸秆和玉米秸秆),对其进行组分分析(工业分析、元素分析、纤维组成),借助差热-热重仪对其燃烧动力学特性进行研究。结果表明:三种秸秆中水稻秸秆灰分和综纤维素含量最高,小麦秸秆中S、Hg含量最高,其他工业分析(水分、挥发分、固定碳)和元素(C、H、O、N)组成均无明显差异。不同升温速率下,三种秸秆的TG和DTG曲线总体趋势相似,两个明显的失重峰分别对应挥发分的析出和燃烧阶段、固定碳燃烧阶段,且前者的失重率远高于后者;同一升温速率下,三种秸秆在低温燃烧区(挥发分析出和燃烧)的最大失重率由高到低依次为小麦秸秆>水稻秸秆>玉米秸秆,而高温燃烧区(固定碳的燃烧)玉米和水稻秸秆的最大失重率没有明显差别,均高于小麦秸秆。秸秆低温区燃烧和高温区燃烧动力学过程均符合二级燃烧动力学方程。研究表明,三种秸秆具有高挥发分、低灰分(水稻秸秆除外)、低硫的特点;秸秆的燃烧失重主要是挥发分的析出和燃烧,其次是固定碳的燃烧,而水分蒸发贡献量最少;快速失重峰形不仅与秸秆的组成有关,还与挥发分初析温度高低有关;双组分分阶段反应模型能够科学地描述农作物秸秆的燃烧动力学过程。
In order to discuss the composition and the combustion characteristics of typical crop straws from a typical region of China, three typical crop straws(wheat straw, rice straw, and corn straw)were chosen from typical crop straw planting areas(Hebei Province and Jilin Province). The compositions(industrial analysis, elemental analysis, and fiber composition)were analyzed and the combustion dynamics characteristics were studied using different heat and a thermogravimetric analyzer. The results showed that the contents of ash and synthetic cellulose of the rice straw were the highest among the three straws, and that the contents of S and Hg of the corn straw were the highest. Other industrial analyses(moisture, volatile matter, and fixed carbon)and element(C, H, O, and N)compositions showed no significant differences. At different heating rates, the overall trends of the TG and DTG curves of the three straws were similar. The two distinct weightlessness peaks corresponded to the precipitation and combustion stage of volatile matter and the combustion stage of fixed carbon, respectively;the weight loss rate of the former was much higher than that of the latter. At the same heating rates, the maximum weight loss rates of the three straws in the low temperature combustion zone(volatile matter precipitation and combustion stage)were from high to low in the order of wheat straw > rice straw > corn straw, while those of the rice straw and corn straw in the high temperature combustion zone(fixed carbon combustion stage)showed no significant difference, and both were higher than that of wheat straw. The combustion process of the straws in the low temperature zone and high temperature zone accorded with the two-stage combustion kinetics equation. The results indicated that the three straws had the characteristics of high volatile matter, low ash(except rice straw), and low sulfur contents. The weight loss of straw combustion was mainly due to volatile matter precipitation and combustion followed by fixed carbon combustion, while the contribution of water evaporation was the least. The peak shape of fast weightlessness was not only related to the composition of straw, but also to the initial precipitation temperature of volatile matter. The two-stage reaction model can scientifically describe the combustion kinetics of crop straws.
In order to discuss the composition and the combustion characteristics of typical crop straws from a typical region of China, three typical crop straws(wheat straw, rice straw, and corn straw)were chosen from typical crop straw planting areas(Hebei Province and Jilin Province). The compositions(industrial analysis, elemental analysis, and fiber composition)were analyzed and the combustion dynamics characteristics were studied using different heat and a thermogravimetric analyzer. The results showed that the contents of ash and synthetic cellulose of the rice straw were the highest among the three straws, and that the contents of S and Hg of the corn straw were the highest. Other industrial analyses(moisture, volatile matter, and fixed carbon)and element(C, H, O, and N)compositions showed no significant differences. At different heating rates, the overall trends of the TG and DTG curves of the three straws were similar. The two distinct weightlessness peaks corresponded to the precipitation and combustion stage of volatile matter and the combustion stage of fixed carbon, respectively;the weight loss rate of the former was much higher than that of the latter. At the same heating rates, the maximum weight loss rates of the three straws in the low temperature combustion zone(volatile matter precipitation and combustion stage)were from high to low in the order of wheat straw > rice straw > corn straw, while those of the rice straw and corn straw in the high temperature combustion zone(fixed carbon combustion stage)showed no significant difference, and both were higher than that of wheat straw. The combustion process of the straws in the low temperature zone and high temperature zone accorded with the two-stage combustion kinetics equation. The results indicated that the three straws had the characteristics of high volatile matter, low ash(except rice straw), and low sulfur contents. The weight loss of straw combustion was mainly due to volatile matter precipitation and combustion followed by fixed carbon combustion, while the contribution of water evaporation was the least. The peak shape of fast weightlessness was not only related to the composition of straw, but also to the initial precipitation temperature of volatile matter. The two-stage reaction model can scientifically describe the combustion kinetics of crop straws.
引文
[1]高广东. JYL4-75活塞式生物质燃料压块机的研制[D].哈尔滨:哈尔滨工业大学, 2010.GAO Guang-dong. The study and manufacture of JYL4-75 biomass briquetting machine[D]. Harbin:Harbin Institute of Technology, 2010.
[2]农业部新闻办公室.我国主要农作物秸秆综合利用率超过80%[J].农业机械, 2016(6):31.Ministry of Agriculture Information Office. The main crops straw stalk comprehensive utilization rate of more than 80%[J]. Farm Machinery,2016(6):31.
[3]于彬.辽宁省秸秆能源化利用对策研究[D].北京:中国农业科学院, 2013.YU Bin. Study on countermeasures of straw energy~oriented utilisation in Liaoning Province[D]. Beijing:Chinese Academy of Agricultural Sciences, 2013.
[4] Hani S H, Ahmad H, Arshad A S, et al. Pyrolysis and combustion kinetics of date palm biomass using thermogravimetric analysis[J]. Bioresource Technology, 2012, 118(1):382-389.
[5] Sahu S G, Sarkar P, Chakraborty N, et al. Thermogravimetric assessment of combustion characteristics of blends of a coal with different biomass chars[J]. Fuel Processing Technology, 2010, 91(3):369-378.
[6]司耀辉,陈汉平,王贤华,等.农业秸秆燃烧特性及动力学分析[J].华中科技大学学报:自然科学版, 2012, 40(1):128-132.SI Yao-hui, CHEN Han-ping, WANG Xian-hua, et al. Combustion characteristics and kinetic analysis of agricultural straw[J]. Journal of Huazhong University of Science and Technology:Natural Science Edition, 2012, 40(1):128-132.
[7]牛文娟.主要农作物秸秆组成成分和能源利用潜力[D].北京:中国农业大学, 2015.NIU Wen-juan. Physicochemical composition and energy potential of main crop straw and stalk[D]. Beijing:China Agricultural University,2015.
[8]宋卫东,王教领,王明友,等.江苏省3个不同地区水稻秸秆的主要化学成分研究[J].安徽农业科学, 2015, 43(1):179-181.SONG Wei-dong, WANG Jiao-ling, WANG Ming-you, et al. Study on main chemical compositions of rice straw in three different areas of Jiangsu Province[J]. Journal of Anhui Agricultural Sciences, 2015, 43(1):179-181.
[9] Hays M D, Fine P M, Geron C D, et al. Open burning of agricultural biomass:Physical and chemical properties of particle-phase emissions[J]. Atmospheric Environment, 2003, 39(36):6747-6764.
[10]陈义龙,韩旭,张岩丰.生物质秸秆燃烧动力学特性研究[J].武汉大学学报(工学版), 2013, 46(6):804-810.CHEN Yi-long, HAN Xu, ZHANG Yan-feng. Combustion kinetics property analysis of biomass straw[J]. Engineering Journal of Wuhan University, 2013, 46(6):804-810.
[11]田松峰,罗伟光,荆有印,等.玉米秸秆燃烧过程及燃烧动力学分析[J].太阳能学报, 2008(12):125-128.TIAN Song-feng, LUO Wei-guang, JING You-yin, et al. Combustion process and kinetics analysis of cornstalk[J]. Acta Energiae Solaris Sinica, 2008(12):125-128.
[12]中国国家标准化管理委员会. GB/T 28731—2012固体生物质燃料工业分析方法[S].北京:中国标准出版社, 2012.Standardization Administration of the People′s Republic of China.GB/T 28731—2012 Proximate analysis of solid biofuels[S]. Beijing:China Standards Press, 2012.
[13]王金主,王元秀,李峰,等.玉米秸秆中纤维素、半纤维素和木质素的测定[J].山东食品发酵, 2010(3):44-47.WANG Jin-zhu, WANG Yuan-xiu, LI Feng, et al. Determination of cellulose, hemicellulose and lignin in corn stalk[J]. Shandong Food Ferment, 2010(3):44-47.
[14]杨国荣.浅议中国神木煤煤质特征及工业利用方向[J].煤化工,1994(4):31-35.YANG Guo-rong. On the characteristics and industrial utilization of Shenmu coals in China[J]. Coal Chemical Industry, 1994(4):31-35.
[15]魏文.中国农村地区生物质燃料燃烧的汞排放研究[D].北京:北京大学, 2012.WEI Wen. Emission of mercury from biomass fuels burning in rural China[D]. Beijing:Peking University, 2012.
[16]陈云,张喜燕,雷亚芳,等.麦秸的微观构造及化学成分分析[J].西北农林科技大学学报(自然科学版), 2015, 43(2):179-190.CHEN Yun, ZHANG Xi-yan, LEI Ya-fang, et al. Microstructure and chemical composition of wheat straw[J]. Journal of Northwest A&F University(Nat Sci Ed), 2015, 43(2):179-190.
[17] Coast A W, Redfern J P. Kinetic parameters form the thermogravimetric data[J]. Nature, 1964, 201(l):68-69.
[18]刘正光,张静.柠条燃烧特性及燃烧动力学研究[J].太阳能学报, 2017, 38(9):2611-2618.LIU Zheng-guang, ZHANG Jing. Study on the combustion characteristics and kinetics of Caragana korshinskii Kom.[J]. Acta Energiae Solaris Sinica, 2017, 38(9):2611-2618.
[19]何成兵,黄建国,孟庆微,等.玉米秸秆燃烧过程及燃烧动力学分析[J].物理学报, 2013(23):211-217.HE Cheng-bing, HUANG Jian-guo, MENG qing-wei, et al. Combustion process and kinetics analysis of cornstalk[J]. Acta Physica Sinica,2013(23):211-217.
[20]王连勇,孙文强,蔡九菊.不同种类生物质的燃烧特性分析[J].冶金能源, 2017, 36(增刊2):71-75.WANG Lian-yong, SUN Wen-qiang, CAI Jiu-ju. Analyze on combustion characteristics of different types of biomass[J]. Energy for Metallurgical Industry, 2017, 36(Suppl 2):71-75.
[21]张萌.生物质与低挥发分煤粉共燃特性的试验研究[D].济南:山东建筑大学, 2016.ZHANG Meng. Experimental study on the combustion characteristics of low volatile pulverized coal blended with biomass[D]. Jinan:Shandong Jianzhu University, 2016.
[2]农业部新闻办公室.我国主要农作物秸秆综合利用率超过80%[J].农业机械, 2016(6):31.Ministry of Agriculture Information Office. The main crops straw stalk comprehensive utilization rate of more than 80%[J]. Farm Machinery,2016(6):31.
[3]于彬.辽宁省秸秆能源化利用对策研究[D].北京:中国农业科学院, 2013.YU Bin. Study on countermeasures of straw energy~oriented utilisation in Liaoning Province[D]. Beijing:Chinese Academy of Agricultural Sciences, 2013.
[4] Hani S H, Ahmad H, Arshad A S, et al. Pyrolysis and combustion kinetics of date palm biomass using thermogravimetric analysis[J]. Bioresource Technology, 2012, 118(1):382-389.
[5] Sahu S G, Sarkar P, Chakraborty N, et al. Thermogravimetric assessment of combustion characteristics of blends of a coal with different biomass chars[J]. Fuel Processing Technology, 2010, 91(3):369-378.
[6]司耀辉,陈汉平,王贤华,等.农业秸秆燃烧特性及动力学分析[J].华中科技大学学报:自然科学版, 2012, 40(1):128-132.SI Yao-hui, CHEN Han-ping, WANG Xian-hua, et al. Combustion characteristics and kinetic analysis of agricultural straw[J]. Journal of Huazhong University of Science and Technology:Natural Science Edition, 2012, 40(1):128-132.
[7]牛文娟.主要农作物秸秆组成成分和能源利用潜力[D].北京:中国农业大学, 2015.NIU Wen-juan. Physicochemical composition and energy potential of main crop straw and stalk[D]. Beijing:China Agricultural University,2015.
[8]宋卫东,王教领,王明友,等.江苏省3个不同地区水稻秸秆的主要化学成分研究[J].安徽农业科学, 2015, 43(1):179-181.SONG Wei-dong, WANG Jiao-ling, WANG Ming-you, et al. Study on main chemical compositions of rice straw in three different areas of Jiangsu Province[J]. Journal of Anhui Agricultural Sciences, 2015, 43(1):179-181.
[9] Hays M D, Fine P M, Geron C D, et al. Open burning of agricultural biomass:Physical and chemical properties of particle-phase emissions[J]. Atmospheric Environment, 2003, 39(36):6747-6764.
[10]陈义龙,韩旭,张岩丰.生物质秸秆燃烧动力学特性研究[J].武汉大学学报(工学版), 2013, 46(6):804-810.CHEN Yi-long, HAN Xu, ZHANG Yan-feng. Combustion kinetics property analysis of biomass straw[J]. Engineering Journal of Wuhan University, 2013, 46(6):804-810.
[11]田松峰,罗伟光,荆有印,等.玉米秸秆燃烧过程及燃烧动力学分析[J].太阳能学报, 2008(12):125-128.TIAN Song-feng, LUO Wei-guang, JING You-yin, et al. Combustion process and kinetics analysis of cornstalk[J]. Acta Energiae Solaris Sinica, 2008(12):125-128.
[12]中国国家标准化管理委员会. GB/T 28731—2012固体生物质燃料工业分析方法[S].北京:中国标准出版社, 2012.Standardization Administration of the People′s Republic of China.GB/T 28731—2012 Proximate analysis of solid biofuels[S]. Beijing:China Standards Press, 2012.
[13]王金主,王元秀,李峰,等.玉米秸秆中纤维素、半纤维素和木质素的测定[J].山东食品发酵, 2010(3):44-47.WANG Jin-zhu, WANG Yuan-xiu, LI Feng, et al. Determination of cellulose, hemicellulose and lignin in corn stalk[J]. Shandong Food Ferment, 2010(3):44-47.
[14]杨国荣.浅议中国神木煤煤质特征及工业利用方向[J].煤化工,1994(4):31-35.YANG Guo-rong. On the characteristics and industrial utilization of Shenmu coals in China[J]. Coal Chemical Industry, 1994(4):31-35.
[15]魏文.中国农村地区生物质燃料燃烧的汞排放研究[D].北京:北京大学, 2012.WEI Wen. Emission of mercury from biomass fuels burning in rural China[D]. Beijing:Peking University, 2012.
[16]陈云,张喜燕,雷亚芳,等.麦秸的微观构造及化学成分分析[J].西北农林科技大学学报(自然科学版), 2015, 43(2):179-190.CHEN Yun, ZHANG Xi-yan, LEI Ya-fang, et al. Microstructure and chemical composition of wheat straw[J]. Journal of Northwest A&F University(Nat Sci Ed), 2015, 43(2):179-190.
[17] Coast A W, Redfern J P. Kinetic parameters form the thermogravimetric data[J]. Nature, 1964, 201(l):68-69.
[18]刘正光,张静.柠条燃烧特性及燃烧动力学研究[J].太阳能学报, 2017, 38(9):2611-2618.LIU Zheng-guang, ZHANG Jing. Study on the combustion characteristics and kinetics of Caragana korshinskii Kom.[J]. Acta Energiae Solaris Sinica, 2017, 38(9):2611-2618.
[19]何成兵,黄建国,孟庆微,等.玉米秸秆燃烧过程及燃烧动力学分析[J].物理学报, 2013(23):211-217.HE Cheng-bing, HUANG Jian-guo, MENG qing-wei, et al. Combustion process and kinetics analysis of cornstalk[J]. Acta Physica Sinica,2013(23):211-217.
[20]王连勇,孙文强,蔡九菊.不同种类生物质的燃烧特性分析[J].冶金能源, 2017, 36(增刊2):71-75.WANG Lian-yong, SUN Wen-qiang, CAI Jiu-ju. Analyze on combustion characteristics of different types of biomass[J]. Energy for Metallurgical Industry, 2017, 36(Suppl 2):71-75.
[21]张萌.生物质与低挥发分煤粉共燃特性的试验研究[D].济南:山东建筑大学, 2016.ZHANG Meng. Experimental study on the combustion characteristics of low volatile pulverized coal blended with biomass[D]. Jinan:Shandong Jianzhu University, 2016.