Fractionating and Purifying Softwood Kraft Lignin with Aqueous Renewable Solvents: Liquid–Liquid Equilibrium for the Lignin–Ethanol–Water System
Fractionating and Purifying Softwood Kraft Lignin with Aqueous Renewable Solvents: Liquid–Liquid Equilibrium for the Lignin–Ethanol–Water System
复制标题
使用水性可再生溶剂分馏和纯化软木硫酸盐木质素：木质素-乙醇-水系统的液-液平衡
DOI：
10.1002/cssc.202000701
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发表时间：
2020
期刊：
影响因子：
8.4
通讯作者：
Thies, Mark C.
中科院分区：
文献类型：
--
作者：
Tindall, Graham W.;Chong, Josh;Miyasato, Evan;Thies, Mark C.
热乙醇-水溶液可用于通过热剂水溶液木质素纯化（ALPHA）工艺同时压裂和纯化软木硫酸盐木质素，使用在选定温度和溶剂-木质素进料（S/F）比下形成的液-液平衡（LLE）区域。测量了处于相互平衡的富溶剂（SR）和富木质素（LR）液相的木质素、乙醇和水组成，以及两相之间的木质素和金属质量分布。如为了清楚起见在准三元图中所描绘的，温度和S/F比两者都可以用于生长、合并甚至分裂LLE的区域，从而对分子量（MW）和木质素纯度两者都给予显著控制。例如，在75 °C下包含45：55 EtOH/H2O和6：1的S/F比的溶剂能够在LR相中回收超纯（除去95%的Na）、更高MW（Mn=8400 Da）的木质素级分。 另一方面，在45 °C和S/F=3：1下的95：5EtOH/H2O使得能够在SR相中回收超纯的低MW（1500 Da）木质素。
Hot ethanol–water solutions can be used to simultaneously fractionate and purify softwood Kraft lignin through the Aqueous Lignin Purification with Hot Agents (ALPHA) process, using the regions of liquid–liquid equilibrium (LLE) that form at selected temperatures and solvent‐to‐lignin feed (S/F) ratios. Lignin, ethanol, and water compositions are measured for the solvent‐rich (SR) and lignin‐rich (LR) liquid phases in mutual equilibrium, as well as the lignin and metals mass distributions between the two phases. As depicted in quasi‐ternary diagrams for clarity, both temperature and S/F ratio can be used to grow, merge, and even split the regions of LLE, giving significant control over both molecular weight (MW) and lignin purity. For example, a solvent comprising 45:55 EtOH/H2O at 75 °C and an S/F ratio of 6:1 enables recovery of an ultrapure (95 % of Na removed), higher MW (Mn=8400 Da) lignin fraction in the LR phase. On the other hand, 95:5 EtOH/H2O at 45 °C and S/F=3:1 enables recovery of an ultrapure, low MW (1500 Da) lignin in the SR phase.