水-乙醇中碱木质素的催化解聚研究

Catalytic depolymerization of Kraft lignin in water-ethanol

摘要:

通过元素分析仪和X射线荧光光谱对碱木质素组成进行了分析。在水-乙醇（v（水）:v（乙醇）=50:50）溶剂中280 oC，2 MPa初始氢压下降解碱木质素。利用傅里叶变换红外光谱(FT-IR)对反应前后碱木质素结构进行了表征，产物中醚键减少，碳氢键增加。利用气相色谱-质谱联用仪(GC-MS)和配有氢火焰离子化检测仪气相色谱 (GC-FID)对单体产物进行定性定量分析，无催化剂时单酚收率为4.57 wt%。磷化镍催化剂的加入可使单酚收率翻倍，磷化钼作为催化剂时单酚收率与磷化镍作为催化剂时相似，但出现苯甲醇类物质和大量的直链含氧有机物，单酚选择性很低。

Abstract:

Elementary and X-Ray Fluorescence analysis were used to investigate the elemental component of Kraft lignin. Kraft lignin was valorized in water-ethanol mixture (v（water）:v（ethanol）=50:50) with 2 MPa initial H2 pressure. FT-IR was used for the analysis of the structure of Kraft lignin before and after reaction, and the results showed that ether bond decreased while C-H bond increased in the products. The monomer products were qualitative and quantitative analyzed with GC-MS and GC-FID, respectively. The total yield of monophenols was 4.57 wt% without catalyst. The introduction of Ni2P doubled the monophenols yield. When MoP was used as the catalyst, the yield of monophenols is similar to that obtained through Ni2P catalyzed process. However, benzyl alcohols and considerable amount of linear oxygen-containing organics were observed, leading to decrease of monophenols selectivity.