Efficient recovery of benzene and n-propanol from wastewater via vapor recompression assisted extractive distillation based on techno-economic and environmental analysis

N-propanol and benzene are important chemical organic compounds, which widely exist in wastewater of chemical industry, medicine and other fields. Because they form azeotrope with water, extractive distillation was used to separate them. In order to increase the efficiency of energy utilization, vapor recompression technology was added on the basis of extractive distillation. On the basis of vapor recompression assisted extractive distillation, energy integration was carried out according to pinch technology, and the optimal energy utilization method was found. The exergy loss and gas emission of each process were studied and analyzed. The results show that the vapor recompression assisted distillation process with feed preheating can reduce the heat duty and gas emissions, and improve exergy efficiency and economic performance. Therefore, the vapor recompression assisted distillation process with feed preheating can effectively treat the wastewater containing benzene / n-propanol. It has the advantages of low cost, energy saving and environmental protection, which is of great significance to the development of environmental protection industry. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

The combination of vapor recompression technology and extractive distillation technology in treating wastewater containing benzene/n-propanol can improve energy efficiency, reduce gas emissions, and enhance economic performance, demonstrating its advantages in environmental protection and energy saving.