Abstract:
Fischer-Tropsch synthesis water contains various oxygen-containing organic compounds such as alcohols, aldehydes, ketones, acids, and esters. The complex azeotropic systems and high water content resulted in long extraction processes and high energy consumption for oxygen-containing organic compounds. To address such issues, a coupled process of salting-out–pervaporation–dividing wall column is proposed. This process first obtained crude methanol through a methanol concentration column. Then, salting-out was used to break the high-water-content azeotropic system, combined with evaporation to remove most of the azeotropic water that could not be removed by conventional distillation, thereby avoiding the high energy consumption issues caused by solvent recycling in traditional azeotropic distillation and extraction distillation. The low-water-content mixed components obtained through salting out were further processed using pervaporation to completely remove water. Finally, ethanol, 1-propanol, and C
4-C
7 alcohols were separated within a single column using a dividing wall column. The results showed that compared with conventional separation processes, the coupled process of salting-out–pervaporation–dividing wall column significantly reduced energy consumption by 79.17% and annual total costs by 69.93%.This process fully utilizes the separation advantages of distillation, salting-out, and pervaporation in different concentration ranges, achieving optimal coupling throughout the entire process. The research conclusions are beneficial for the extraction of oxygen-containing organic compounds and provide an effective pathway for their high-value conversion.