Process synthesis and 4E evaluation of hybrid reactive distillation processes for the ethanol and tert-butanol recovery from wastewater

Aiming at achieving the high-purity recovery of ethanol (EtOH) and tert-butanol (TBA) from industrial waste with low carbon emission, the processes intensified by hybrid reactive distillation combined with pressure-swing distillation (PSD) and extractive distillation (ED) are proposed in this work. The optimum procedure of the sequential iterative method is applied to select an optimal pressure for these hybrid reactive distillation pro-cesses. From the economic and environmental impact perspective, the results indicated that the reactive -extractive-/pressure-swing hybrid distillation has significant economic and environmental advantages. The REPDC-REPC (reactive-extractive-/pressure-swing hybrid distillation) process is the most potential and competitive, saving 56.47% TAC and reducing 69.23% CO2 emissions, and has 67.51% thermodynamic effi-ciency, minor exergy destruction, and most enormous total exergy efficiency. Meanwhile, the work also dem-onstrates that the operating pressure of the column plays an important role, which positively affects the energy saving of the recovery process.

Automated summary

In this study, hybrid reactive distillation combined with pressure-swing distillation (PSD) and extractive distillation (ED) processes were proposed to achieve high-purity recovery of ethanol (EtOH) and tert-butanol (TBA) from industrial waste with low carbon emission. The results showed that the reactive-extractive-/pressure-swing hybrid distillation had significant economic and environmental advantages. The REPDC-REPC process saved 56.47% total annual cost (TAC), reduced 69.23% CO2 emissions, and had 67.51% thermodynamic efficiency, minor exergy destruction, and the highest total exergy efficiency.