Li Si-jin, Mu Jun, Zhang Yu
Guang Pu Xue Yu Guang Pu Fen Xi. 2014 Jun;34(6):1497-501.
Pyrolysis is an efficient and recycling way to utilize waste wood-based panels, in which urea-formaldehyde resin (UF) is the main difference between wood-based board and other kinds of biomass. The present paper studied the three main components (cellulose, hemicelluloses, lignin) of poplar wood, in order to effectively and environmentally utilize or dispose of waste wood-based panels with pyrolysis technique, to study the influence of urea formaldehyde resin on pyrolytic characteristic of wood during the process of the pyrolysis of waste wood-based panels, and to in-depth explore the mechanism of the effect of UF on each component of wood. Innovatively, the weight-loss character and gas evolution rule of the model (made from cellulose, xylan and lignin, based on the chemical components stud of poplar wood), the main components as well as the ones mixed with UF were analyzed by TG-FTIR (thermogravimetric analyzer coupled to a Fourier transform infrared spectrometer). Results indicated that UF promoted the generation of water and carboxylic acid substances during the cellulose pyrolysis process. UF combined with lignin, formed some kind of unstable nitrogenous structure which produced a large amount of NH3, which took part in the low-temperature (200-300 degrees C) pyrolysis of lignin, and directly affected the production of pyrolysis products. It can be concluded that during the process of the pyrolysis of waste wood-based panels, lignin was the one that UF mainly impacted among the three main components of wood.
热解是一种高效且可回收利用废弃木质板材的方法，其中脲醛树脂（UF）是木质板材与其他生物质的主要区别所在。本文研究了杨木的三种主要成分（纤维素、半纤维素、木质素），以便利用热解技术有效且环保地利用或处置废弃木质板材，研究脲醛树脂在废弃木质板材热解过程中对木材热解特性的影响，并深入探究脲醛树脂对木材各成分作用的机理。创新之处在于，通过TG-FTIR（热重分析仪与傅里叶变换红外光谱仪联用）分析了模型（基于杨木化学成分研究，由纤维素、木聚糖和木质素制成）、主要成分以及与脲醛树脂混合后的失重特性和气体逸出规律。结果表明，脲醛树脂在纤维素热解过程中促进了水和羧酸类物质的生成。脲醛树脂与木质素结合，形成了某种不稳定的含氮结构，产生了大量NH₃，其参与了木质素的低温（200 - 300℃）热解，并直接影响热解产物的生成。可以得出结论，在废弃木质板材热解过程中，木质素是脲醛树脂对木材三种主要成分中影响最大的一种。
