Combining steam distillation with microwave-assisted pyrolysis to maximise direct production of levoglucosenone from agricultural wastes
Combining steam distillation with microwave-assisted pyrolysis to maximise direct production of levoglucosenone from agricultural wastes
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DOI：
10.1039/c8gc02994f
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发表时间：
2019-03-21
期刊：
影响因子：
9.8
通讯作者：
Budarin, Vitally
中科院分区：
文献类型：
--
作者：
Bouxin, Florent P.;Clark, James H.;Budarin, Vitally
通过半纤维素去除的大麦秸秆的热解和自诱导水蒸气蒸馏相结合的方法，研究了在生物精炼厂使用湿农业废弃物的有利影响。结果表明，水蒸气蒸馏法既能选择性地分离左旋糖苷酮(LGO)等多糖产物，又能获得较高的产率。大麦秸秆的酸度对产物选择性的影响最大。当酸质量分数小于0.8wt%时，产物的分布主要是通过水解途径和热解途径进行的，对左旋葡聚糖和LGO等热解产物有较高的选择性。有趣的是，水分含量的增加增加了产物的总体产率，但对产物的选择性没有影响，这表明水分对分解途径没有直接影响。水的原位汽化产生一个微波透明的蒸汽环境，防止蒸馏产品进一步降解。观察到在木质素存在下多糖的选择性微波活化，为后续木质纤维生物质的转化提供了重要的机会。
The favourable impact of using a wet waste stream of agricultural residues in a biorefinery was studied through a combination of pyrolysis and self-induced steam distillation of hemicellulose depleted barley straw. The results showed that steam distillation provided both selective isolation and higher yields of polysaccharide-derived products such as levoglucosenone (LGO). The acid content of pretreated barley straw had the highest impact on the products selectivity. Both hydrolytic and pyrolytic pathways contributed to the products distribution, with higher selectivity toward pyrolytic products such as levoglucosan and LGO when less than 0.8 wt% acid was used. Interestingly, the increase of water content increased the overall products yields but had no impact on the products selectivity suggesting that the water did not directly impact on the decomposition pathway. In situ vaporisation of the water generates a microwave transparent steam environment preventing the distilled products for further degradation. The observation of the selective microwave activation of the polysaccharides in the presence of lignin offers significant opportunities for subsequent conversion of lignocellulosic biomass.