Haaz Eniko, Fozer Daniel, Toth Andras Jozsef
Department of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest H-1111, Hungary.
ACS Omega. 2021 Jan 5;6(2):1289-1298. doi: 10.1021/acsomega.0c04750. eCollection 2021 Jan 19.
Acetaldehyde diethyl acetal (herein called acetal) is an important pollutant of anhydrous ethanol. Isobaric vapor-liquid equilibrium (VLE) of an ethanol-acetal binary system was measured using a vapor condensate and liquid circulation VLE still. The experimental data were correlated with Wilson, nonrandom two-liquid (NRTL), and universal quasichemical (UNIQUAC) activity coefficient models, which were found suitable for representing the VLE data. Proper agreements between experimental and calculated VLE data were obtained, which were then confirmed with consistency tests. The applicability of the novel VLE data was demonstrated during an investigation of an anhydrous ethanol purification column. Reduction of the concentration of acetal and other pollutants was examined and optimized in a flowsheet environment. The modeling results were verified in a laboratory with an experimental distillation column, confirming a correct agreement between the results. It must be highlighted that the developed method is suitable for the production of pharmacopeial quality anhydrous alcohol, based on reliable, verified VLE data. The results show the importance of accurate VLE data in critical compositions (low pollutant content); moreover, aiming at high product purity, experimental validation has paramount importance. The consistency between the three platforms (VLE and distillation experiments and flowsheet simulation) confirms the accuracy of the developed method.
乙醛二乙缩醛（以下简称乙缩醛）是无水乙醇的一种重要污染物。使用蒸汽冷凝液和液体循环汽液平衡釜测定了乙醇 - 乙缩醛二元体系的等压汽液平衡（VLE）。实验数据与威尔逊（Wilson）、非随机双液体（NRTL）和通用似化学（UNIQUAC）活度系数模型进行了关联，发现这些模型适用于表示VLE数据。实验和计算得到的VLE数据之间取得了适当的一致性，随后通过一致性检验得到了证实。在对无水乙醇纯化塔的研究中证明了新的VLE数据的适用性。在流程环境中研究并优化了乙缩醛和其他污染物浓度的降低。在实验室中用实验蒸馏塔对建模结果进行了验证，结果之间的一致性得到了确认。必须强调的是，基于可靠、经验证的VLE数据，所开发的方法适用于生产药典级无水乙醇。结果表明，准确的VLE数据在关键组成（低污染物含量）中具有重要性；此外，为了实现高产品纯度，实验验证至关重要。三个平台（VLE和蒸馏实验以及流程模拟）之间的一致性证实了所开发方法的准确性。
