Chen Bo-Xuan, Guo Yan, Fan Jia-le, Li Bao-Zhong, Tan Chuan-Qiao, Li Dong-Hui, Hu Hai-Qing, Hu Tong-Xin
School of Forestry, Northeast Forestry University, Harbin 150040, China.
Ying Yong Sheng Tai Xue Bao. 2022 Jan;33(1):76-84. doi: 10.13287/j.1001-9332.202201.012.
Forest fuels are the basis of fire occurrences, while ground dead fuels are an important part of forest fuels. Undestanding the pyrolysis characteristics and gas emissions of forest fuels is of great significance to explore the effects of forest fire on atmospheric environment and carbon balance, as well as to prevent and combat forest fire. In this study, the thermogravimetric analysis and gas emission analysis were conducted on leaf litter of six tree species ( var. , , , , , ) in Heilongjiang Province to explore the pyrolysis process and combustibility of forest fuels, to analyze their pyrolysis characteristics, pyrolysis kinetics characteristics, gas emission characteristics. A four-dimensional evaluation of their combustibility was conducted based on pyrolysis parameters. The results showed that the pyrolysis temperature of holocellulose in the leaves of those six tree species ranged in 143.31-180.48 ℃ at the beginning and 345.04-394.38 ℃ at the end, lignin pyrolysis temperature ranged in 345.04-394.38 ℃ at the beginning and 582.85-609.31 ℃ at the end. The pyrolysis of the six kinds of arbor blades during the pyrolysis process affected fuel ash content, quality and temperature of the total pyrolysis. The activation energies of two main pyrolysis stages of leaves of six tree species were 18.88-27.08 kJ·mol and 13.25-27.54 kJ·mol, respectively, and the pre-exponential factors were 3.13-26.28 min and 1.30-22.55 min. The holocellulose activation energy and pre-exponential factor of the pyrolysis stage for , , , and were greater than that of the lignin pyrolysis stage, while the opposite was true for var. and . The release amounts of CO and CO at the pyrolysis stage of the holocellulose was 535.16-880.11 mg·m and 7004.97-10302.05 mg·m, and that at the pyrolysis stage of lignin was 240.31-1104.67 mg·m and 20425.60-33946.68 mg·m, respectively. The release of CO and CO at the pyrolysis stage of healdellulose was less, but mass loss was greater than that at the pyrolysis stage of lignin. In the four-dimensional combustibility ranking of the six tree species leaves, was the best ignitable, was the most combustible, and var. was the most sustainable and consumable. The ignitability was significantly positively correlated with pyrolysis kinetics parameters of the holocellulose, while the sustainability was negatively correlated with that of lignin.
森林燃料是火灾发生的基础，而地面死燃料是森林燃料的重要组成部分。了解森林燃料的热解特性和气体排放对于探究森林火灾对大气环境和碳平衡的影响以及预防和扑救森林火灾具有重要意义。本研究对黑龙江省六种树种（ 变种、 、 、 、 、 ）的落叶进行了热重分析和气体排放分析，以探究森林燃料的热解过程和燃烧性，分析其热解特性、热解动力学特性、气体排放特性。基于热解参数对其燃烧性进行了四维评价。结果表明，这六种树种叶片中全纤维素的热解温度开始时在143.31 - 180.48℃范围内，结束时在345.04 - 394.38℃范围内，木质素热解温度开始时在345.04 - 394.38℃范围内，结束时在582.85 - 609.31℃范围内。六种乔木叶片在热解过程中的热解影响了燃料灰分含量、总热解质量和温度。六种树种叶片两个主要热解阶段的活化能分别为18.88 - 27.08 kJ·mol和13.25 - 27.54 kJ·mol，指前因子分别为3.13 - 26.28 min和1.30 - 22.55 min。 、 、 、 和 的全纤维素热解阶段的活化能和指前因子大于木质素热解阶段，而 变种和 的情况则相反。全纤维素热解阶段CO和CO的释放量分别为535.16 - 880.11 mg·m和7004.97 - 10302.05 mg·m，木质素热解阶段CO和CO的释放量分别为240.31 - 1104.67 mg·m和20425.60 - 33946.68 mg·m。全纤维素热解阶段CO和CO的释放量较少，但质量损失大于木质素热解阶段。在六种树种叶片的四维燃烧性排名中， 最易点燃， 最易燃， 变种最耐燃且最易消耗。可燃性与全纤维素的热解动力学参数显著正相关，而耐燃性与木质素的热解动力学参数负相关。
