Large-scale biorefineries converting lignocellulosic biomass into chemicals, fuels and energy require a cost-effective pretreatment process that can effectively fractionate the three main lignocellulose constituents from a wide variety of feedstocks. A mild organosolv process has been developed using acetone as solvent. Herbaceous biomass (wheat straw and corn stover), hardwood (beech, poplar and birch) and softwood (spruce and pine) were fractionated using near-identical process conditions: 140 °C, 120 min, 50% w/w aqueous acetone and sulfuric acid. For herbaceous biomass and hardwood, effective pretreatment and subsequent enzymatic cellulose hydrolysis into glucose was observed in combination with a high yield of monomeric hemicellulose sugars and lignin. In the case of softwood, poor delignification hampered enzymatic cellulose hydrolysis, despite efficient hemicellulose removal. To assess solvent stability, the impact of temperature, time and acid dose on the degree of acetone self-condensation was explored. The process conditions used for feedstock screening resulted in a 1.4% w/w conversion of acetone to mainly diacetone alcohol and mesityl oxide. For wheat straw, shortening the reaction time to 60 min resulted in reduced solvent self-condensation (1.0% w/w) and improved hemicellulose sugar yield (86%). In sum, effective fractionation was demonstrated for various herbaceous and hardwood feedstocks combined with limited acetone loss due to self-condensation.

中文翻译：

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使用温和的丙酮有机溶剂法对草本生物量和硬木中的木质纤维素进行有效分级

将木质纤维素生物质转化为化学品，燃料和能源的大型生物炼油厂需要经济高效的预处理工艺，该工艺可以有效地从多种原料中分离出三种主要的木质纤维素成分。已经开发出使用丙酮作为溶剂的温和的有机溶剂法。使用接近相同的工艺条件对草本生物质（小麦秸秆和玉米秸秆），硬木（山毛榉，杨树和桦木）和软木（云杉和松树）进行分馏：140°C，120分钟，50％w / w的丙酮水溶液和硫酸酸。对于草本生物质和硬木，观察到有效的预处理以及随后的酶促纤维素水解为葡萄糖，以及高产量的单体半纤维素糖和木质素的组合。就软木而言，脱木素作用差会阻碍酶促纤维素的水解，尽管有效去除半纤维素。为了评估溶剂的稳定性，探讨了温度，时间和酸剂量对丙酮自缩合度的影响。用于原料筛选的工艺条件导致1.4％w / w的丙酮转化成主要是双丙酮醇和异亚丙基丙酮。对于小麦秸秆，将反应时间缩短至60分钟可减少溶剂的自冷凝（1.0％w / w）和提高的半纤维素糖收率（86％）。总而言之，证明了对各种草本和阔叶树原料的有效分馏，以及由于自身冷凝而造成的丙酮损失有限。用于原料筛选的工艺条件导致1.4％w / w的丙酮转化成主要是双丙酮醇和异亚丙基丙酮。对于小麦秸秆，将反应时间缩短至60分钟可减少溶剂的自冷凝（1.0％w / w）和提高的半纤维素糖收率（86％）。总而言之，证明了对各种草本和阔叶树原料的有效分馏，以及由于自身冷凝而造成的丙酮损失有限。用于原料筛选的工艺条件导致1.4％w / w的丙酮转化成主要是双丙酮醇和异亚丙基丙酮。对于小麦秸秆，将反应时间缩短至60分钟可减少溶剂的自冷凝（1.0％w / w）和提高的半纤维素糖收率（86％）。总而言之，证明了对各种草本和阔叶树原料的有效分馏，以及由于自身冷凝而造成的丙酮损失有限。