Inorganic Chemistry and Catalysis group Debye Institute for NanoMaterials Science, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht, The Netherlands.
ChemSusChem. 2011 Mar 21;4(3):369-78. doi: 10.1002/cssc.201000299. Epub 2011 Jan 18.
The solubilization and aqueous phase reforming of lignin, including kraft, soda, and alcell lignin along with sugarcane bagasse, at low temperatures (T≤498 K) and pressures (P≤29 bar) is reported for the first time for the production of aromatic chemicals and hydrogen. Analysis of lignin model compounds and the distribution of products obtained during the lignin aqueous phase reforming revealed that lignin was depolymerized through disruption of the abundant β-O-4 linkages and, to a lesser extent, the 5-5' carbon-carbon linkages to form monomeric aromatic compounds. The alkyl chains contained on these monomeric compounds were readily reformed to produce hydrogen and simple aromatic platform chemicals, particularly guaiacol and syringol, with the distribution of each depending on the lignin source. The methoxy groups present on the aromatic rings were subject to hydrolysis to form methanol, which was also readily reformed to produce hydrogen and carbon dioxide. The composition of the isolated yields of monomeric aromatic compounds and overall lignin conversion based on these isolated yields varied from 10-15% depending on the lignin sample, with the balance consisting of gaseous products and residual solid material. Furthermore, we introduce the use of a high-pressure autoclave with optical windows and an autoclave with ATR-IR sentinel for on-line in situ spectroscopic monitoring of biomass conversion processes, which provides direct insight into, for example, the solubilization process and aqueous phase reforming reaction of lignin.
首次报道了在低温（T≤498 K）和低压（P≤29 bar）条件下，木质素（包括 kraft、苏打和 alcell 木质素）以及甘蔗渣的增溶和水相重整，以生产芳香族化学品和氢气。对木质素模型化合物的分析和水相重整过程中获得的产物分布表明，木质素通过破坏丰富的β-O-4 键以及在较小程度上破坏 5-5' 碳-碳键解聚，形成单体芳香族化合物。这些单体化合物上的烷基链容易重整生成氢气和简单的芳香族平台化学品，特别是愈创木酚和丁香酚，每种化合物的分布取决于木质素的来源。芳环上存在的甲氧基易于水解生成甲醇，甲醇也容易重整生成氢气和二氧化碳。基于这些分离收率的单体芳香族化合物的分离收率和整体木质素转化率的组成变化范围为 10-15%，具体取决于木质素样品，其余部分由气态产物和残余固体材料组成。此外，我们引入了带有光学窗的高压高压釜和带有ATR-IR 监测器的高压釜，用于生物质转化过程的在线原位光谱监测，这为例如木质素的溶解过程和水相重整反应提供了直接的了解。
