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 (M_n=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.

中文翻译：

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用水性可再生溶剂分馏和纯化软木牛皮纸木质素：木质素-乙醇-水系统的液-液平衡。

通过使用在选定温度和溶剂至溶剂下形成的液-液平衡（LLE）区域，可使用热乙醇-水溶液通过热剂进行木质素水纯化（ALPHA）过程同时分馏和纯化软木牛皮纸硫酸盐木质素。木质素进料（S / F）比。木质素，乙醇和水的组成可以测量相互平衡的富溶剂（SR）和富木质素（LR）液相，以及两相之间的木质素和金属质量分布。如为清晰起见，在准三元图中所示，温度和S / F比率均可用于生长，合并甚至分裂LLE区域，从而可显着控制分子量（MW）和木质素纯度。例如，包含45:55 EtOH / H ₂的溶剂O在75°C和S / F比为6：1的情况下，可以回收超纯（LR中的95％的Na除去），更高的MW（M _n = 8400 Da）木质素。另一方面，在45°C和S / F = 3：1的情况下，使用95：5 EtOH / H ₂ O可以在SR相中回收超纯的低分子量（1500 Da）木质素。