Intensified and optimized processes for simultaneously recovering isopropanol, butanol, and ethanol from fermentation broth: From seven columns to heat-pump-assisted dual DWCs

Journal article, 2026

Biobutanol production is a promising route for renewable chemical manufacturing. However, the downstream process for simultaneously recovering isopropanol, butanol, and ethanol from fermentation broth remains highly energy-intensive due to multiple azeotropes and close-boiling components. To address this challenge, twelve intensified and optimized processes using various intensification technologies (i.e. vapor recompression heat pumps, double-effect distillation, heterogeneous azeotropic distillation, extractive distillation, and dividing-wall column) have been proposed based on a conventional seven-column process. Based on the evaluation in terms of the energy efficiency, CO2 emission, and economic performance, a novel heat-pump-assisted dual dividing-wall column process, which combines a heat-pump-assisted azeotropic dividing-wall column and four components extractive dividing-wall column shows the best performance among all processes. A sequential optimization method was also proposed to determine the process parameters for the four components extractive dividing-wall column. As compared to a conventional seven-column process, the novel process shows a reduction of 57.00%, 68.38%, and 52.10% of energy consumption, CO2 emission (using clean electricity for heat pump), and cost, respectively. A further pinch analysis shows that the energy consumption of the novel process can be reduced by 61.57% compared with the conventional seven-column process.