Abstract

This work addresses a microwave-assisted, NaCl–H₂O/γ-valerolactone (GVL) solvent system for the co-production of 5-hydroxymethylfurfural (HMF) and saccharides from cellulose, examining the effects of the solvent system (H₂O/GVL), NaCl concentration and reaction time. Oligosaccharides and glucose were completely recovered in the aqueous phase and their yields varied between 4–67 and 0–16 wt%, respectively, while HMF was largely recovered in the organic phase, in a yield between 0 and 13 wt%. Increasing the proportion of H₂O in the system promoted cellulose depolymerisation and increased the production of oligosaccharides and glucose. This latter underwent a further decomposition to yield HMF and carboxylic acids when long times were used. An increase in NaCl not only kinetically promoted cellulose decomposition, but also modified the solubility of cellulose decomposition products in the aqueous phase, thus playing a very important role on the products distribution within both phases. With a solvent system consisting of 67/33 vol% H₂O/GVL, with 30 wt% NaCl at 220 °C for 18 min, it is possible to selectively convert 76% of the cellulose into a sugar-rich aqueous solution and a rich HMF organic phase. The former was made up of glucose (25%) and oligosaccharides (64%), while the later mainly comprised HMF (75%). This might help the development of new biomass pre-processing technologies, allowing the co-production of precursors for the chemical and biological industries.

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抽象的

这项工作研究了一种微波辅助的NaCl–H ₂ O /γ-戊内酯（GVL）溶剂系统，该系统可从纤维素共同生产5-羟甲基糠醛（HMF）和糖类，研究溶剂系统（H ₂ O / GVL），NaCl浓度和反应时间。寡糖和葡萄糖在水相中被完全回收，其收率分别在4–67和0–16 wt％之间变化，而HMF在有机相中被大量回收，收率在0至13 wt％之间。增加H ₂的比例系统中的O促进纤维素解聚，并增加寡糖和葡萄糖的产量。当使用长时间时，后者进一步分解以产生HMF和羧酸。NaCl的增加不仅在动力学上促进了纤维素的分解，而且还改变了纤维素分解产物在水相中的溶解度，因此对产物在两相中的分布起着非常重要的作用。使用由67/33 vol％H ₂组成的溶剂系统在220°C下用30 wt％NaCl的O / GVL处理18分钟，可以选择性地将76％的纤维素转化为富含糖的水溶液和富含HMF的有机相。前者由葡萄糖（25％）和低聚糖（64％）组成，而后者主要由HMF（75％）组成。这可能有助于开发新的生物质预处理技术，从而可以共同生产用于化学和生物工业的前体。

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