Diaminomethanal (an organic compound), was examined as entrainer for dehydration of isopropanol−water system by extractive distillation. Isobaric vapor−liquid equilibrium (VLE) data were studied for isopropanol−water−diaminomethanal system at 101.3 kPa, employing modified Othmer type still. The VLE data studied for the system comprising diaminomethanal were quite different from that of diaminomethanal-free system. The diaminomethanal represented a significant increase in the relative volatility of the isopropanol−water solution and led to termination of the azeotrope at a specific concentration. It was observed that the relative volatility for isopropanol−water mixture increases continuously with the increase in diaminomethanal concentration till 15.7 mol%. Results demonstrate that diaminomethanal is a functional entrainer for the separation of isopropanol−water mixture and 13 mol% of diaminomethanal concentration is enough to terminate the azeotrope. Furthermore, the experimental VLE data for ternary system were correlated by nonrandom two-liquid (NRTL) model and predicted values correlated with the experimental data very well. Further, the experimental data was verified for thermodynamic consistency by Wisniak–Tamir’s modification of McDermott-Ellis and Wisniak’s L-W thermodynamic consistency test.

中文翻译：

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使用二氨基甲醛作为夹带剂分离异丙醇 + 水混合物

二氨基甲烷醛（一种有机化合物）被用作萃取蒸馏异丙醇-水系统脱水的夹带剂。使用改进的 Othmer 型蒸馏器，在 101.3 kPa 下研究了异丙醇-水-二氨基甲醛系统的等压气-液平衡 (VLE) 数据。为包含二氨基甲烷的系统研究的 VLE 数据与不含二氨基甲烷的系统的 VLE 数据完全不同。二氨基甲烷表明异丙醇-水溶液的相对挥发性显着增加，并导致特定浓度的共沸物终止。观察到异丙醇-水混合物的相对挥发性随着二氨基甲烷浓度的增加而持续增加，直至 15.7 mol%。结果表明，二氨基甲醇是分离异丙醇-水混合物的功能性夹带剂，13 mol% 的二氨基甲醇浓度足以终止共沸混合物。此外，三元系统的实验 VLE 数据通过非随机双液 (NRTL) 模型相关联，预测值与实验数据很好地相关。此外，通过 Wisniak-Tamir 对 McDermott-Ellis 的修改和 Wisniak 的 LW 热力学一致性测试验证了实验数据的热力学一致性。