Depolymerization of concentrated sulfuric acid hydrolysis lignin to high-yield aromatic monomers in basic sub- and supercritical fluids
Depolymerization of concentrated sulfuric acid hydrolysis lignin to high-yield aromatic monomers in basic sub- and supercritical fluids
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DOI：
10.1016/j.cej.2017.02.045
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发表时间：
2017-06-01
影响因子：
15.1
通讯作者：
Kim, Jaehoon
中科院分区：
文献类型：
--
作者：
Hidajat, Marcel Jonathan;Riaz, Asim;Kim, Jaehoon
在亚超临界和超临界流体中，利用碱催化解聚（BCD）将木质素转化为高产率的芳香族单体。碱催化剂的作用（NaOH、KOH和Na 2CO 3），反应介质（亚临界水（subH（2）O）和超临界甲醇（scMeOH）），以及木质素的类型（浓硫酸水解木质素（CSAHL）和硫酸盐木质素（KL））对木质素转化率和产物产率的影响研究了天然气、生物油、固体残渣和芳族单体的产率，以了解决定芳族单体产率的主导因素。KL木质素在subH（2）O-NaOH中在330 ℃下处理30分钟导致21.5wt%的高单体产率。在相同的反应条件下，少量的CSAHL（17.9重量%）转化为芳族单体;低产率是由于CSAHL的抗性性质。在scMeOH中，单体产率低得多（3.3- 7.8wt%），并且固体残余物产率比由subH（2）O获得的那些（单体产率，6.2- 17.9wt%;固体残余物产率，16- 17wt%）高得多（约26- 31wt%）。在subH（2）O-碱性介质中产生的最丰富的单体是儿茶酚及其烷基化和烷氧基化衍生物，而在scMeOH-碱性介质中产生的那些是甲氧基化苯和甲苯物质，因为scMeOH独特的O-烷基化能力。(c)2017爱思唯尔B. V.保留所有权利。
Conversion of lignin into high-yield aromatic monomers is investigated using base-catalyzed depolymerization (BCD) in sub- and supercritical fluids. The effects of the base catalysts (NaOH, KOH, and Na2CO3), reaction media (subcritical water (subH(2)O) and supercritical methanol (scMeOH)), and type of lignin (concentrated sulfuric acid hydrolysis lignin (CSAHL) and Kraft lignin (KL)) on the lignin conversion and product yields (gas, bio-oil, solid residue, and aromatic monomers) are explored to understand dominant factors determining the aromatic monomer yield. Treatment of KL lignin in subH(2)O-NaOH at 330 degrees C for 30 min results in a high monomeric yield of 21.5 wt%. Under identical reaction conditions, a low amount of CSAHL (17.9 wt%) is converted to aromatic monomers; the low yield results from the resistant nature of CSAHL. In scMeOH, the monomeric yields are much lower (3.3-7.8 wt%), and the solid residue yields are much higher (about 26-31 wt%) than those obtained from subH(2)O (monomeric yields, 6.2-17.9 wt%; solid-residue yields, 16-17 wt%). The most abundant monomers produced in the subH(2)O-basic media are catechols and their alkylated and alkoxylated derivatives, while those produced in the scMeOH-basic media are methoxylated benzene and toluene species because of the unique O-alkylation ability of scMeOH. (c) 2017 Elsevier B.V. All rights reserved.