Abejón Ricardo, Rabadán Javier, Garea Aurora, Irabien Angel
Chemical and Biomolecular Engineering Department, University of Cantabria. Avda. Los Castros s/n, 39005 Santander, Cantabria, Spain.
Membranes (Basel). 2020 Feb 14;10(2):29. doi: 10.3390/membranes10020029.
Lignin is one of the three main components of lignocellulosic biomass and must be considered a raw material with attractive applications from an economic and ecological point of view. Therefore, biorefineries must have in mind the most adequate processing to obtain high-quality lignin and the separation tasks that play a key role to improve the purity of the lignin. Separation techniques based on membranes are a promising way to achieve these requirements. In this work, the separation performance of the SILM (Supported Ionic Liquid Membrane) formed with [BMIM][DBP] as IL (Ionic Liquid) and PTFE as membrane support was compared to a nanofiltration (NF) membrane (NP010 by Microdyn-Nadir) and two ultrafiltration (UF) membranes (UF5 and UF10 by Trisep). The SILM showed selective transport of Kraft lignin, lignosulphonate, xylose, and glucose in aqueous solutions. Although it was stable under different conditions and its performance was improved by the integration of agitation, it was not competitive when compared to NF and UF membranes, although the latter ones suffered fouling. The NF membrane was the best alternative for the separation of lignosulphonates from monosaccharides (separation factors around 75 while SILM attained only values lower than 3), while the UF5 membrane should be selected to separate Kraft lignin and monosaccharides (separation factors around 100 while SILM attained only values below 3).
木质素是木质纤维素生物质的三大主要成分之一，从经济和生态角度来看，必须将其视为具有诱人应用前景的原材料。因此，生物精炼厂必须考虑采用最适当的工艺来获得高质量的木质素，以及那些对提高木质素纯度起着关键作用的分离任务。基于膜的分离技术是满足这些要求的一种很有前景的方法。在这项工作中，将以[BMIM][DBP]作为离子液体（IL）、聚四氟乙烯作为膜支撑体形成的支撑离子液体膜（SILM）的分离性能，与一种纳滤（NF）膜（Microdyn-Nadir公司的NP010）和两种超滤（UF）膜（Trisep公司的UF5和UF10）进行了比较。SILM在水溶液中对硫酸盐木质素、木素磺酸盐、木糖和葡萄糖表现出选择性传输。尽管它在不同条件下稳定，且通过搅拌其性能有所提高，但与NF膜和UF膜相比，它没有竞争力，尽管后两者存在污染问题。NF膜是从单糖中分离木素磺酸盐的最佳选择（分离因子约为75，而SILM仅达到低于3的值），而应选择UF5膜来分离硫酸盐木质素和单糖（分离因子约为100，而SILM仅达到低于3的值）。
