Department of Forest Products Technology, Aalto University School of Chemical Technology, 00076 Aalto, Finland.
ChemSusChem. 2012 Aug;5(8):1625-37. doi: 10.1002/cssc.201100600. Epub 2012 Jun 27.
SO(2)-ethanol-water (SEW) lignocellulosic fractionation has the potential to overcome the present techno-economic barriers that hinder the commercial implementation of renewable transportation fuel production. In this study, SEW fractionation of spruce wood chips is examined for its ability to separate the main wood components, hemicelluloses, lignin, and cellulose, and the potential to recover SO(2) and ethanol from the spent fractionation liquid. Therefore, overall sulfur and carbohydrate mass balances are established. 95-97 % of the charged SO(2) remains in the liquid and can be fully recovered by distillation. During fractionation, hemicelluloses and lignin are effectively dissolved, whereas cellulose is preserved in the solid (fibre) phase. Hemicelluloses are hydrolysed, producing up to 50 % monomeric sugars, whereas dehydration and oxidation of carbohydrates are insignificant. The latter is proven by the closed carbohydrate material balances as well as by the near absence of corresponding by-products (furfural, hydroxymethylfurfural (HMF) and aldonic acids). In addition, acid methanolysis/GC and acid hydrolysis/high performance anion exchange chromatography (HPAEC) methods for the carbohydrate determination are compared.
SO(2)-乙醇-水（SEW）木质纤维素分级法有可能克服目前阻碍可再生运输燃料生产商业化实施的技术经济障碍。在这项研究中，考察了 SEW 分级法分离云杉木屑的主要木材成分（半纤维素、木质素和纤维素）的能力，以及从用过的分级液中回收 SO(2)和乙醇的潜力。因此，建立了总的硫和碳水化合物质量平衡。95-97%的已加载 SO(2)仍留在液体中，并可通过蒸馏完全回收。在分级过程中，半纤维素和木质素被有效溶解，而纤维素则保留在固体（纤维）相中。半纤维素发生水解，产生高达 50%的单糖，而碳水化合物的脱水和氧化作用则微不足道。这一点从封闭的碳水化合物物质平衡以及几乎不存在相应的副产物（糠醛、羟甲基糠醛（HMF）和醛糖酸）得到了证明。此外，还比较了用于碳水化合物测定的酸甲醇解/GC 和酸水解/高效阴离子交换色谱（HPAEC）方法。
