Pyrolysis Dynamics Calculation and Pyrolysis Gases Analysis of Wood Particles

doi:10.12034/j.issn.1009-606X.217128

Abstract

Abstract: To explore the effect of atmosphere on the pyrolysis reaction of compressed wood chips particles, the thermo-gravimetric experiments with carbon dioxide and dry air as the dynamic gases under heating rates of 10, 20, 30℃/min were conducted by using synchronous thermal analyzer. Aiming at the second mass loss stage of thermo-gravimetric curves, the software of Netzsch Thermokinetics 3 was used to analyze the reaction orders, and Coats?Redfern method was used to calculate the kinetic parameters. Moreover, gas chromatography was applied to determine the composition of pyrolysis gases produced from enlarged experiment of thermo-gravimetric experiment at the heating rate of 10℃/min. The results showed that there are 3 weightless stages in the heating process of wood particle under these two kinds of atmosphere. In carbon dioxide and dry air, the second stage weight loss were 65.97% and 56.31%, the thermal decomposition reaction series were 1.23 and 1.0, the activation energies of this pyrolysis phase were117.73 and 87.4 kJ/mol, and the pre-exponential factor were 5.8×106 and 1.1×104 min?1, respectively. In the pyrolysis gases, the concentration of methane is lower in carbon dioxide than in dry air, while hydrogen and carbon monoxide are higher.

Key words: wood particles, CO2, thermal analysis kinetics, Coats-Redfern, apparent activation energy

摘要： 以CO2和干空气为动态气氛，在10, 20, 30℃/min三种升温速率下进行热重实验，研究了气氛对压缩木屑颗粒热解反应的影响，用Netzsch Thermokinetics 3软件确定了失重曲线第2失重阶段的反应级数，用Coats?Redfern积分法计算了第2失重阶段的动力学参数，用气相色谱分析了放大实验在升温速率10℃/min下产生的热解气体成分. 结果表明，在CO2和干空气气氛下，随温度升高，木屑颗粒均出现3个失重阶段，第2阶段的失重分别为65.97%和56.31%，热解反应级数分别为1.2和1.0，活化能分别为117.73和87.4 kJ/mol，指前因子分别为5.8?106和1.1?104 min?1. 与空气气氛相比，CO2气氛下裂解气中CH4产量相对较低，而H2和CO产量较高.

关键词: 木屑颗粒, 二氧化碳, 热分析动力学, Coats-Redfern, 表观活化能

Congcong YUAN Yudong WANG Dingchuan ZHANG Bin YANG Yongnian DAI. Pyrolysis Dynamics Calculation and Pyrolysis Gases Analysis of Wood Particles[J]. Chin. J. Process Eng., 2017, 17(5): 1102-1108.

袁聪聪王宇栋张丁川杨斌戴永年. 木屑颗粒热解过程动力学计算及热解气体分析[J]. 过程工程学报, 2017, 17(5): 1102-1108.

References

[1]张百良. 生物质成型燃料技术与工程化[M]. 北京：科学出版社，2012.
[2]陈纪忠，邓天异，蒋斌波．竹材热解动力学的研究[J]．林产化学与工业，2005，25(2)：11-15．
[3]任学勇，杜洪双，王文亮，等．基于TG—FTIR的落叶松木材热失重与热解气相演变规律研究[J].光谱学与光谱分析，2012，32(4)：944-948．
[4]郑志锋，黄元波，蒋剑春，等．核桃壳热解行为及动力学研究[J]．林产化学与工业，2010,30(2):6-10．
[5] 金顶峰，杨潇，吴盼盼，等.多孔玉米淀粉热分解反应动力学[J]. 高校化学工程学报，2015,29(6): 1371-1376.
[6] 董存珍，汪小憨，曾小军，等.CO2气氛下生物焦气化反应动力学参数的实验研究. I活化能[J].燃料化学学报，2014,42(3): 329-335.
[7] 孙云娟，蒋剑春，王燕杰,等. Coats-Redfern积分法研究生物质与煤单独热解和共热解动力学特性[J].林产业与化学，2014,34(5): 8-14.
[8] WANG Guang-wei, ZHANG Jian-liang, SHAO Jiu-gang. Experimental and modeling studies on CO2 gasification of biomass Chars [J]. Energy, 2016(114):143-154.
[9] M.F. Irfan, M.R. Usman, K. Kusakabe. Coal gasification in CO2 atmosphere and its kinetics since 1948: a brief review [J]. Energy, 2011 (36): 12-40.
[10] C. Gonzalo-Tirado, S. Jimenez, J. Ballester. Gasification of a pulverized sub-bituminous coal in CO2 at atmospheric pressure [J].Combust and Flame, 2012(159): 385–395.
[11] C.Gonzalo-Tirado, S. Jimenez, J. Ballester. Kinetics of CO2 gasification for coals of different ranks under oxy-combustion conditions [J].Combust and Flame, 2013 (160):411–416.
[12]FSC Mustata，N Tudorachi，A Mustata, et al. Physical and thermal characterization of some cellulose fabrics as reinforced materials for composite[J].Journal of Thermal Analysis and Calorimetry,2015, 120(3):1703-1714.
[13]刘荣厚，牛卫生，张大雷.生物质热化学转化技术[M].北京：化学工业出版社，2005.
[14]刘仁庆.纤维素化学基础[M].北京：科学出版社，1985.
[15] 田红，廖正祝.粤西地区生物质热解特性及其动力学[J].太阳能学报,2015,36(03): 641-646.
[16]唐谟堂，李运姣.冶金设备基础—传递原理及物料输送(M).长沙：中南大学出版社，2003:310-313.
[17] GAI Chao, DONG Yu-ping, ZHANG Tong-hui, et al. The kinetic analysis of the pyrolysis of agricultural residue under non-isothermal conditions[J].Bioresoure Technology,2013(127):298-305.
[18]John E. White, W. James Catallo, Benjamin L. Legendre. Biomass pyrolysis kinetics: a comparative critical review with relevant agricultural residue case studies [J].Journal of Analytical and Applied Pyrolysis, 2011, 91(1):1-33.
[19] DU Yu-ying, JIANG Xu-guang, LV Guo-jun, et al. Thermal behavior and kinetics of bio-ferment residue/coal blends during co-pyrolysis [J]. Energy Conversion and Management, 2014(88): 459-463.
[20] LU Ke-miao, LEE Wen-jhy, CHEN Wei-hsin, et al. Thermogravimetric analysis and kinetics of co-pyrolysis of raw/torrefied wood and coal blends[J]. Applied Energy, 2013(15):57-65.
[21] CHEN Jian-biao, MU Lin, YIN Hong-chao, et al. Thermogravimetric analysis and kinetics of the combustion of refining and chemicals wastewater in different oxygen concentrations[J]. Journal of Thermal Analysis and Calorimetry,2015, 119(3): 2205-2219.
[22]班彩英，生物质热解气化的动力学研究及熵产分析[C].硕士论文. 保定，华北电力大学， 2015.
[23]孙庆雷，李文，陈皓侃，等. DAEM和Coats-Redfern积分法研究煤半焦燃烧动力学的比较[J].化工进展,2003, 54(11):1598-1602.
[24]胡荣祖，史启祯，高胜利，张同来，张建军，赵凤起.热分析动力学[M].第二版，北京：科学出版2008:54-55.
[25]Coats A W, Redfern J P. Kinetic parameters from thermogravimetric data [J].Nature, 1964, 201(4914):68-69.
[26]廖艳芬，纤维素热裂解机理试验研究[C].博士论文，杭州，浙江大学，2003.
[27] Antal J J, Varhegyi G. Cellulose pyrolysis Kinetics: The Current State of Knowledge [J]. industrial & engineering chemistry research,1995, 34(3):703-717.
[28] Miller R S, Bellan J. A generalized biomass pyrolysis model based on superimposed cellulose, hemicellulose and lignin kinetics[J].Combust Science and Technology,1997(126):97-137.
[29] CHEN Jianbiao, FAN Xiao-tian, JIANG Bo, et al. Pyrolysis of oil-plant wastes in a TGA and a fixed-bed reactor:Thermochemical behaviors, kinetics, and products characterization[J]. Bioresource Technology, 2015:592-602.
[30] WANG Chang-an, ZHANG Xiao-ming, LIU Yin-he, et al. Pyrolysis and combustion characteristics of coals in oxyfuel combustion[J].Applied Energy, 2012(97): 264-273.
[31]孙立，张晓东.生物质热解气化原理与技术[M].北京：化学工业出版社,2012: 28-129.