Low molecular weight alcohols such as ethanol, propanol and butanol are currently gaining attention owing to their complete combustion and higher calorific value. These low molecular weight alcohols are obtained by ABE (acetone−butanol−ethanol) fermentation, where they are produced within an aqueous phase. Extraction is contemplated as one of the effective methods for the separation of these lower alcohols from aqueous phase through a solvent. The solvent explored here relates to the formulation of Deep Eutectic Solvent (DES) comprising of DL-menthol (Hydrogen Bond Donor) + decanoic acid (Hydrogen Bond Acceptor). The current work adopts a multiscale approach leading with DES preparation and subsequent batch scale Liquid-Liquid Equilibria (LLE) measurement and finally concludes through process simulation studies. The experimental LLE data of DES (1)-Alcohol (2)-Water (3) gave a higher affinity towards alcohol and lower solubility with water. The experimental results were thereafter regressed with the NRTL model using the additional constraint where a positive tangent plane distance is imposed for all the tie lines within the Gibbs energy of mixing (G_m) surface. The average absolute RMSD values correlated via NRTL and COSMO-SAC model were found to be 0.003 and 0.008 respectively. A flow sheet with a hybrid extraction-distillation system is then proposed and simulated for the solvent recovery, scale-up and cost analysis.

低分子量的醇，例如乙醇，丙醇和丁醇，由于其完全燃烧和较高的热值而受到关注。这些低分子量的醇是通过ABE（丙酮-丁醇-乙醇）发酵获得的，它们在水相中产生。萃取被认为是通过溶剂从水相中分离这些低级醇的有效方法之一。此处探索的溶剂涉及由DL-薄荷醇（氢键供体）+癸酸（氢键受体）组成的深共晶溶剂（DES）的配方。当前的工作采用多尺度方法进行DES制备，随后进行批生产规模的液-液平衡（LLE）测量，最后通过过程仿真研究得出结论。DES（1）-醇（2）-水（3）的实验LLE数据显示出对醇的更高亲和力和更低的水溶解度。此后，使用附加约束将实验结果与NRTL模型进行回归，其中对Gibbs混合能（G_m）表面。通过NRTL和COSMO-SAC模型关联的平均绝对RMSD值分别为0.003和0.008。然后提出了带有混合萃取-蒸馏系统的流程图，并对其进行了模拟，以进行溶剂回收，规模放大和成本分析。