Deep eutectic solvent (DES) has demonstrated its ability to improve the yield and selectivity in the 5-hydroxymethylfurfural (HMF) production process. Liquid–liquid extraction is a beneficial process in HMF production to recover HMF from the reaction medium. In the present study, the effect of DES (choline chloride urea) on the liquid–liquid equilibria (LLE) of HMF–water–organic solvent (methyl isobutyl ketone (MIBK) or 2-pentanol) systems in the absence and presence of sodium chloride (NaCl) was investigated at 313.15 K and atmospheric pressure (0.1 MPa). The tie-lines of the multicomponent systems were measured using several analytical methods. According to the experimental results, the extraction performance decreased with an increase in DES concentration. However, the addition of 10 wt % NaCl into the HMF aqueous DES solution can induce stronger liquid–liquid phase splitting, enhancing the separation factors and distribution coefficients of HMF by around 2.7 and 1.6 times, respectively. Additionally, MIBK showed better extraction performance in the presence of DES and NaCl with the separation factors 2.6 times higher than those of 2-pentanol and the HMF distribution coefficients above 1.8. The LLE of the multicomponent systems were correlated well with the nonrandom two-liquid (NRTL) model.

中文翻译：

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氯化胆碱尿素对 5-羟甲基糠醛-水-有机溶剂体系在氯化钠不存在和存在下的液-液平衡的影响

深共熔溶剂 (DES) 已证明其能够提高 5-羟甲基糠醛 (HMF) 生产过程的产率和选择性。液-液萃取是 HMF 生产中从反应介质中回收 HMF 的有益过程。在本研究中，DES（氯化胆碱尿素）对 HMF-水-有机溶剂（甲基异丁基酮 (MIBK) 或 2-戊醇）系统在无钠和有钠的情况下的液-液平衡 (LLE) 的影响在 313.15 K 和大气压 (0.1 MPa) 下研究氯化物 (NaCl)。使用多种分析方法测量多组分系统的连接线。根据实验结果，提取性能随着DES浓度的增加而降低。然而，在 HMF DES 水溶液中加入 10 wt% NaCl 可以引起更强的液-液相分裂，将 HMF 的分离因子和分配系数分别提高约 2.7 和 1.6 倍。此外，在 DES 和 NaCl 存在下，MIBK 表现出更好的提取性能，分离因子比 2-戊醇高 2.6 倍，HMF 分配系数高于 1.8。多组分系统的 LLE 与非随机二液 (NRTL) 模型相关性良好。比2-戊醇高6倍，HMF分配系数大于1.8。多组分系统的 LLE 与非随机二液 (NRTL) 模型相关性良好。比2-戊醇高6倍，HMF分配系数大于1.8。多组分系统的 LLE 与非随机二液 (NRTL) 模型相关性良好。