Luo Zhongyang, Lu Kongyu, Yang Yi, Li Simin, Li Guoxiang
State Key Laboratory of Clean Energy Utilization, Zhejiang University Hangzhou 310027 China
RSC Adv. 2019 Oct 8;9(55):31960-31968. doi: 10.1039/c9ra02538c. eCollection 2019 Oct 7.
Catalytic fast pyrolysis of lignin with zeolite catalysts is a promising method to produce aromatic hydrocarbons. In this paper, alkali lignin was used as a model compound to pyrolyze with HZSM-5 (silica to alumina ratio, SAR = 23), HZSM-5(50), HZSM-5(80), HY and Hβ. Non-condensable vapours and condensable fractions were determined and quantified by GC/FID and GC/MS respectively. 7.63 wt% of aromatic hydrocarbons and 3.34 wt% of C1-C4 alkanes and alkenes were acquired. The effects of catalysts and pyrolysis parameters were studied in this work. Different reaction pathways were compared and discussed by combining density functional theory (DFT) calculations. Cyclization reactions to form aromatic hydrocarbons were thought to be the main reaction pathway, while direct demethylation, demethoxylation and dehydration reactions were the secondary reaction pathway to convert phenolic lignin monomers to non-oxygenated aromatic hydrocarbons.
用沸石催化剂对木质素进行催化快速热解是生产芳烃的一种很有前景的方法。本文以碱木质素为模型化合物，与HZSM-5（硅铝比，SAR = 23）、HZSM-5(50)、HZSM-5(80)、HY和Hβ进行热解。分别通过气相色谱/氢火焰离子化检测器（GC/FID）和气相色谱/质谱联用仪（GC/MS）对不可冷凝蒸汽和可冷凝馏分进行测定和定量分析。获得了7.63 wt%的芳烃以及3.34 wt%的C1-C4烷烃和烯烃。本工作研究了催化剂和热解参数的影响。结合密度泛函理论（DFT）计算，对不同的反应途径进行了比较和讨论。形成芳烃的环化反应被认为是主要反应途径，而直接脱甲基、脱甲氧基和脱水反应是将酚类木质素单体转化为非氧化芳烃的次要反应途径。
