DEEP EUTECTIC SOLVENTS BASED ON BETAINE AND PROPYLENE GLYCOL AS POTENTIAL DENITRIFICATION AGENTS: A LIQUID-LIQUID EQUILIBRIUM STUDY

Abstract Two deep eutectic solvents (DES) based on betaine (B) and propylene glycol (PG) in molar ratios of 1:4 and 1:5 were prepared and their physico-chemical properties were determined. Liquid-liquid equilibria at 298.15 K and atmospheric pressure were determined for 13 quasi-three-component systems with a hydrocarbon (n-hexane, n-heptane, i-octane or toluene), solute (pyridine or thiophene) and DES (B-PG 1:4 or B-PG 1:5). Experimental phase diagrams and calculated distribution ratios showed that DESs are more suitable for denitrification than for desulfurization. The equilibria in the investigated systems were described by the NRTL and UNIQUAC models, and good agreement with experiments was obtained.

摘要 以甜菜碱（betaine，B）和丙二醇（propylene glycol，PG）按1:4、1:5的摩尔比制备了两种低共熔溶剂（deep eutectic solvents，DES），并测定了其理化性质。在298.15 K、常压条件下，针对由烃类物质（正己烷、正庚烷、异辛烷或甲苯）、溶质（吡啶或噻吩）以及低共熔溶剂（B-PG 1:4或B-PG 1:5）组成的13组准三组分体系，测定了其液液平衡数据。实验相图与计算得到的分配比结果表明，此类低共熔溶剂相较于脱硫，更适用于脱除氮化物。采用NRTL与UNIQUAC模型对所研究体系的相平衡行为进行拟合，拟合结果与实验数据具有良好的一致性。