Tianjin Engineering Research Center of Biomass Solid Waste Resources Technology, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
Molecules. 2019 Feb 7;24(3):594. doi: 10.3390/molecules24030594.
Furfural is a versatile platform molecule for the synthesis of various chemicals and fuels, and it can be produced by acid-catalyzed dehydration of xylose derived from renewable biomass resources. A series of metal salts and ionic liquids were investigated to obtain the best combination of catalyst and solvent for the conversion of xylose into furfural. A furfural yield of 71.1% was obtained at high xylose loading (20 wt%) from the single-phasic reaction system whereby SnCl₄ was used as catalyst and ionic liquid 1-ethyl-3-methylimidazolium bromide (EMIMBr) was used as reaction medium. Moreover, the combined catalyst consisting of 5 mol% SnCl₄ and 5 mol% MgCl₂ also produced a high furfural yield (68.8%), which was comparable to the furfural yield obtained with 10 mol% SnCl₄. The water⁻organic solvent biphasic systems could improve the furfural yield compared with the single aqueous phase. Although these organic solvents could form biphasic systems with ionic liquid EMIMBr, the furfural yield decreased remarkably compared with the single EMIMBr phase. Besides, the EMIMBr/SnCl₄ system with appropriate water was also efficient to convert xylan and lignocellulosic biomass corn stalk into furfural, obtaining furfural yields as high as 57.3% and 54.5%, respectively.
糠醛是一种多功能的平台分子，可用于合成各种化学品和燃料，它可以通过酸催化脱水由可再生生物质资源中的木糖制得。研究了一系列金属盐和离子液体，以获得用于将木糖转化为糠醛的最佳催化剂和溶剂组合。在高木糖负载量（20wt%）下，从单相反应体系中获得了 71.1%的糠醛收率，其中 SnCl4 用作催化剂，离子液体 1-乙基-3-甲基咪唑溴化物（EMIMBr）用作反应介质。此外，由 5mol%SnCl4 和 5mol%MgCl2 组成的组合催化剂也产生了高糠醛收率（68.8%），与 10mol%SnCl4 获得的糠醛收率相当。水-有机溶剂两相体系与单相水相比可以提高糠醛的收率。尽管这些有机溶剂可以与离子液体 EMIMBr 形成两相体系，但与单相 EMIMBr 相比，糠醛的收率显著降低。此外，含有适量水的 EMIMBr/SnCl4 体系也能有效地将木聚糖和木质纤维素生物质玉米秸秆转化为糠醛，分别获得高达 57.3%和 54.5%的糠醛收率。
