基于Py-GC-MS的木质素与褐煤共热解特性研究

Co-Pyrolysis Characteristics of Lignin and Lignite: Analytical Py-GC-MS Study

褐煤与结构相似的木质素共热解可制备液体燃料或高附加值化学品,提质后的热解焦进一步用于气化,可实现褐煤与木质素的分级高效清洁利用。本研究选用松木木质素、桉木木质素和碱木质素,与褐煤按不同比例混合,采用快速热解-气相色谱-质谱联用(Py-GC-MS)技术对其共热解特性进行研究。通过分析热解产物分布考察共热解的协同作用。实验结果表明,热解产物随着混合比、掺杂木质素种类的不同而变化较大,表现出不同的产物选择性。共热解中,木质素较高的氢碳比能促使对甲酚等产物的产率提高,而碱木质素中较高的碱和碱土金属也发挥了重要的催化作用,提高了愈创木酚和4-甲基愈创木酚等酚类的产率。

Lignin has a similar structure to lignite, liquid fuel and high value-added chemicals can be extracted from their co-pyrolysis liquid, and the pyrolysis coke can be used for further implementation of gasification. In this study, pine lignin, eucalyptus lignin and alkali lignin were selected, and the co-pyrolysis experiment with lignite was carried out respectively by Py-GC-MS at different mixing ratios. The synergistic effect of co-pyrolysis was investigated by analyzing the distribution of pyrolysis products. The experimental results showed that the pyrolysis products changed greatly with the mixing ratio and the types of materials added. In the co-pyrolysis of lignite and lignin, the higher hydrogen to carbon ratio of lignin can promote the yield of some specific products such as p-cresol, while the alkali and alkaline earth metals in alkali lignin also play an important catalytic role. Therefore, the yield of 2-methoxy-phenol, and creosol was enhanced.