Peanut husks are agro-industrial waste and represent about 20 wt% of the peanut harvest. This waste product was subjected to fast pyrolysis in a pyroprobe reactor coupled with GC/MS at temperatures ranging from 350 to 600 °C to maximize levoglucosan production. Prior to pyrolysis, the biomass was washed with acetic acid (10 wt%) to remove the alkali and alkaline earth metals. Levoglucosan production from pretreated biomass increased for all the temperatures studied. However, the best result was observed at 550 °C. At this temperature, 35 wt% of produced levoglucosan was found in the volatile fraction, representing around a nine-fold increase in levoglucosan production compared to the untreated biomass. These results may be due to the removal of the alkali and alkaline earth metals or the morphological changes observed in the biomass via SEM. While the yields of undesirable compounds derived from lignin that interfere with levoglucosan purification and its applications (phenol, guaiacol, syringol and catechol) decreased as the pyrolysis temperature increased, the yields of other compounds (vanillin, eugenol, cresol, 4-methylcyclohexanone, furfural and acetaldehyde) increased. Our results confirm that pretreated peanut husks have great potential in levoglucosan production via fast pyrolysis.

Graphic Abstract

中文翻译：

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花生壳农用工业废料的快速热解：脱水糖（左旋葡聚糖）生产的增强

花生壳是农业工业废料，占花生收成的20％（重量）。该废产物在热探针反应器中与GC / MS一起在350至600°C的温度下进行快速热解，以最大程度地生产左旋葡聚糖。在热解之前，将生物质用乙酸（10重量％）洗涤以除去碱金属和碱土金属。在所有研究温度下，预处理过的生物质产生的左旋葡聚糖产量均增加。但是，最佳结果是在550°C下观察到的。在此温度下，在挥发性馏分中发现了35 wt％的左旋葡聚糖生成物，与未处理的生物质相比，左旋葡聚糖产量增加了约9倍。这些结果可能是由于去除了碱金属和碱土金属或通过SEM在生物质中观察到的形态变化所致。随着热解温度的升高，干扰木质素葡聚糖纯化及其应用（苯酚，愈创木酚，丁香酚和邻苯二酚）的木质素衍生不良化合物的收率下降，而其他化合物（香兰素，丁香酚，甲酚，4-甲基环己酮，糠醛）的收率却有所下降。和乙醛）增加。我们的结果证实，经过预处理的花生壳在通过快速热解生产左旋葡聚糖中具有很大的潜力。

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