基于热红联用分析的木质素热裂解动力学研究

Kinetic Research of Lignin Pyrolysis by TGA-FTIR Analysis

利用热重红外联用系统对生物质的主要组分木质素进行了热裂解动力学研究.在用红外固体压片法研究木质素结构的基础上得到不同升温速率下木质素热裂解的热重曲线.实验结果表明,随着升温速率的增加,各个阶段的起始和终止温度向高温侧轻微移动,主反应区间增加;计算得到的木质素两阶段活化能分别为58.41 kJ/mol和119.98 kJ/mol.与纤维素热解气的联机红外分析谱图相比可知木质素热解过程中气体析出机理复杂,主要生成CO、CH4和呋喃等产物.

Kinetic research on the pyrolysis of lignin was carried out with thermo gravimetric analyzer （TGA） -coupled with a fourier Transform infrared spectrometry （FTIR） system. The typical microstructure of lignin was analyzed by infrared equipment coupled with tabletting pretreatment. Experimental results show that TG and DTG curves moved slightly towards higher temperature with the increase of heating rate, while the main reaction area widened. Lignin pyrolysis was divided into two stages, corresponding with 58.41 k J/tool and 119.98 kJ/mol for activation energy, respectively. Compared with cellulose pyrolysis, online infrared analysis shows that the volatile produced by the lignin pyrolysis had more complicated composition distribution. CO, CH4 and furan appeared to release out during the whole pyrolysis process.