杨木乙醇木素的超临界乙醇催化解聚及其产物分析

Catalytic Depolymerization of Aspen Alcohol Lignin in Superitical Ethanol Solvent and Analysis of the Degraded Products

关键词:  木素  超临界  解聚

Key Words:lignin  supercritical  depolymerization

摘要:研究了以乙醇溶液为溶剂体系,以自制的Cu掺杂类水滑石焙烧产物为催化剂,对杨木乙醇制浆木素进行超临界解聚,反应器容积为100 mL,反应条件为乙醇40 mL,催化剂1 g,杨木乙醇木素2 g,真空状态下加热至300℃,保温8 h后立即冷水冷却至室温。通过气相色谱-质谱联用仪（GC-MS）、核磁共振波谱仪（13C-NMR）及傅里叶红外光谱仪（FT-IR）对解聚产物进行分析检测,得出杨木乙醇木素超临界乙醇催化解聚产物主要为酯类和含苯环类物质。酯类物质主要为己烯酸乙酯、丁酸乙酯和乙酸乙酯,含苯环类物质主要为间二甲苯、甲苯、对异丙基甲苯和邻二甲苯,主要发生酯化反应和烷基化反应。溶剂乙醇在反应中既是封端剂又是供氢剂。

Abstract:The catalytic depolymerization of aspen alcohol lignin was conducted in supercritical ethanol with the catalyst of roasted Cu-doped hydrotalcite-like products in a 100 mL Parr reactor, the reaction conditions included using ethanol 40 mL, catalyst 1 g, lignin 2 g, and heating to 300℃ in vaccum state, then cooling to room temperature immediately after keeping at that tempertature for 8 hours. The analysis results of GC-MS, 13C-NMR and FT-IR showed that the degraded products of lignin were mainly esters and containing benzene ring compounds. Esters mainly included hexene acid ethyl ester, ethyl butyrate and ethyl acetate; containing benzene ring material mainly included m-xylene, toluene, p-cymene and o-xylene. The main reactions were esterification reaction and alkylation reaction. The ethanol solvent acted as the end capping agent and hydrogen donor.