棕垫材料的热解燃烧特性试验研究

Experimental study on the pyrolysis and combustion characteristics via thermo-gravimetric analysis of palm fiber mattress

利用热重分析仪研究了棕垫材料在火灾中的热解燃烧过程。结果表明,在升温速率为20℃/min时,空气气氛下燃烧过程表现为两步反应,在335℃和470℃出现失重峰,总失重率为95%,两阶段反应活化能分别为108.95 kJ/mol和261.15 kJ/mol;氮气气氛下热解表现为一步反应,在335℃出现失重峰,失重率为80%,反应活化能为103.24 kJ/mol。随升温速率增加,棕垫材料的起始分解温度、失重峰值温度及主阶段热解结束温度均向高温侧移动。燃烧过程中低温段活化能增大,高温段则降低;热解过程中活化能增大;反应级数不变。研究表明,棕垫材料与常见生物质可燃物具有类似的热解燃烧性能,其潜在火灾危险性值得人们关注。

In this paper, we would like to present the results of our investigation of the characteristic features of the pyrolysis and com bustion behaviors via a thermogravimetric analysis （TGA） in the air and nitrogen atmosphere of palm fiber mattress sample at the heating rate of 20 ℃/min. For this purpose, we have made an analysis of the impact of the ramping rate on the thermal degradation, thus work ing out the thermal kinetics parameters with the CoatsRcdfern method. The experimental results have shown that at the air atmo sphere, the palm fiber mattress sample has the same characteristics of the thermal degradation as other biomass combustible materials by way of a twostep procedure. As a result, we have found that the peaks of weight loss tend to appear at the temperatures of 335 ℃ to 470 ℃. At the same time, the combustion tends to start in corre spondence with 108.95 kJ/mol and 261.15 kJ/mol for activating the heating energy, with the total weight loss getting up as high as 95 % in all the cases. In contrast to the above case, it turns out feasible for the palm fiber mattress sample to be thermaldegraded by way of the onestep procedure. In case of nitrogen used as a media, the weight loss peak tends to appear at 335 ℃ , with the activation energy being at 103.24 kJ/mol and the total loss weight turning to be going up to 80% . As a rule, with the increase of temperature rate, the initial temperature release and the weight loss peaks tend to appear with the increase of temperature of the palm fiber mattress sample either in the natural air and the nitrogen media. The results of our investigation and exploration have thus shown that the activation energy of the sam ple tends to increase with the temperature rise in the low temperature section, but decrease at the high temperature section in the air medi a; whereas the activation energy has to be increased in the nitrogen gas, though the reaction order is likely to remain invariant in the air and nitrogen media. Moreover, the experimental results of activation energy indicate that the palm fiber mattress has a similar potential of thermal degradation and combustion as the other biomass materials do in the same condition, whose underlying fire risk should never be ne glected.