Biomass processing with ionic liquids (ILs) has been one of the most topical research areas in recent years. However, separation and recovery of biomass products and ILs are currently a challenge. Recovery of produced monosaccharides from an IL postreaction solution and the possibility to reuse the IL are strongly required to guarantee the sustainability of biomass processing. The present study demonstrates a novel approach that aims at separating a biomass hemicellulose‐derived product, namely, xylose, and 1‐ethyl‐3‐methylimidazolium hydrogensulfate ([emim][HSO₄]). High polarity of a postreaction system composed of xylose, IL, and water is one of the major hindrances in the separation performance. A proposed solution is fine‐tuning of the system polarity by the addition of moderately polar acetonitrile. To scrutinize the potential of xylose and IL separation, phase equilibria of a system constituted by [emim][HSO₄], water, and acetonitrile were studied. Additionally, preparative chromatography experiments with alumina as a stationary phase were performed to determine the conditions required for efficient separation of the sugar and the IL by selective adsorption of xylose on alumina in detriment of IL. The amount and treatment of the stationary phase, eluent polarity, and amount of loaded sample were also scrutinized in this study. Treatment of alumina was considered as a necessary step to achieve recovery yields of 90.8 and 98.1 wt % for the IL and xylose, respectively, as separate fractions.

中文翻译：

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分离和回收酸性离子液体水解生物质产生的半纤维素衍生糖

近年来，利用离子液体（IL）进行生物质处理一直是最热门的研究领域之一。然而，生物质产物和IL的分离和回收目前是挑战。从IL后反应溶液中回收产生的单糖和重新使用IL的可能性是非常需要的，以确保生物质加工的可持续性。本研究表明了一种新颖的方法，该方法旨在分离生物质半纤维素衍生的产品，即木糖和1-乙基-3-甲基咪唑硫酸氢盐（[emim] [HSO ₄]）。由木糖，IL和水组成的后反应系统的高极性是分离性能的主要障碍之一。提出的解决方案是通过添加中等极性的乙腈来微调系统极性。为了研究木糖和IL分离的潜力，由[emim] [HSO ₄ ]组成的系统的相平衡研究了水和乙腈。另外，进行了以氧化铝为固定相的制备色谱实验，以确定通过木糖在氧化铝上的选择性吸附而不损害IL来有效分离糖和IL所需的条件。在这项研究中，还研究了固定相的数量和处理，洗脱液的极性以及上样量。氧化铝的处理被认为是实现IL和木糖作为单独的馏分分别达到90.8重量％和98.1重量％的回收率的必要步骤。