Towards Quantitative Catalytic Lignin Depolymerization
Towards Quantitative Catalytic Lignin Depolymerization
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DOI：
10.1002/chem.201002438
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发表时间：
2011-05-01
影响因子：
4.3
通讯作者：
Lercher, Johannes A.
中科院分区：
文献类型：
--
作者：
Roberts, Virginia. M.;Stein, Valentin;Lercher, Johannes A.
木质素碱催化液相水解的产物很大程度上取决于操作条件。通过改变温度、压力、催化剂浓度和停留时间，可以调节解聚木质素的单体和低聚物的产率。结果表明，酚衍生物的单体是碱催化水解的唯一初级产物，低聚物作为次级产物形成。然而，这些高反应性产物的低聚和聚合限制了可获得的含有低分子量酚类产物的产物油的量。因此，抑制水热木质素解聚过程中同时发生的低聚和聚合反应对于提高产品产率非常重要。应用硼酸作为封端剂来抑制最初形成的产物的加成和缩合反应被认为是该方向的成功方法。碱催化木质素水解与硼酸保护剂的添加相结合，使产物分布转向较低分子量化合物，并将产物收率提高到 85% 以上。
The products of base-catalyzed liquid-phase hydrolysis of lignin depend markedly on the operating conditions. By varying temperature, pressure, catalyst concentration, and residence time, the yield of monomers and oligomers from depolymerized lignin can be adjusted. It is shown that monomers of phenolic derivatives are the only primary products of base-catalyzed hydrolysis and that oligomers form as secondary products. Oligomerization and polymerization of these highly reactive products, however, limit the amount of obtainable product oil containing low-molecular-weight phenolic products. Therefore, inhibition of concurrent oligomerization and polymerization reactions during hydrothermal lignin depolymerization is important to enhance product yields. Applying boric acid as a capping agent to suppress addition and condensation reactions of initially formed products is presented as a successful approach in this direction. Combination of base-catalyzed lignin hydrolysis with addition of boric acid protecting agent shifts the product distribution to lower molecular weight compounds and increases product yields beyond 85%.