基于TG-FTIR的落叶松木材热失重与热解气相演变规律研究

采用热重红外光谱联用分析法考察了落叶松木材在不同升温速率下的热失重特性及气相演变规律,并与其组分模混物的热解特性进行了对比分析。结果表明,落叶松的主要失重区域相对于模混物较宽,落叶松残炭率(18.97%)相对于模混物(29.83%)较低;在低温段,模混物的活化能高于落叶松木材,而在高温段二者差别不大;落叶松木材热解过程经历了水分析出、主成分热分解、后期炭化等阶段,气体析出主要集中在375℃左右;落叶松在热解反应过程中,主要气体产物生成量顺序为CO2>H2O>CH4>CO,随着升温速率的增加,上述气体产物的生成量明显增多;模混物与落叶松木材热解生成气体规律基本相似,但模混物中各气体析出强度均相对较高。

Analysis of pyrolysis process and gas evolution rule of larch wood by TG-FTIR

The weight-loss character and gas evolution rule of larch wood at different heating rates were investigated by TG-FTIR (thermogravimetric analyzer coupled to a Fourier transform infrared spectrometer), and the results were compared with those of larch wood model-component mixture. The main weight-loss area of larch wood was wider than larch wood model-component mixture, and the residual char yield of larch wood (18.97%) was lower than larch wood model-component mixture (29.83%). During the pyrolysis process, the activation energy of larch wood model-component mixture was higher than the larch wood's in the low-temperature region, but there was little difference between the two segments in high temperature region. Larch wood came through several stages of water extraction, main component decomposition, charring during its pyrolysis process, and gas precipitation mainly happening at near 375 degrees C. The order of main gas products generated from the larch wood pyrolysis reaction was CO2 > H2O > CH4 > CO, and the gas product yield was significantly increased when the heating rate increased. The larch wood model-component mixture had the similar basic rules of producing gas to larch wood, but the former had relatively higher precipitation density than the latter.