Application of a biodegradable poly(butylene adipate-co-terephthalate) membrane for phenol pervaporation recovery

Abstract

In the field of membrane separation, the environmental concerns caused by spent membranes are becoming increasingly serious, which contradicts the concept of sustainable development. Based on this, a biodegradable poly(butylene adipate-co-terephthalate) (PBAT) membrane was used for the first time in the pervaporation separation of phenol, a high boiling point organic compound (HBOC). By using the PBAT membrane, outstanding separation efficiency was achieved, and environmental pollution and disposal issues were also avoided. The separation process and mechanism of the PBAT membrane were systematically studied through the experiment together with molecular dynamics (MD) simulation. The swelling experiment and intermolecular interaction energy calculation demonstrated that the PBAT membrane had a strong affinity for phenol. Further simulation concluded that higher phenol concentration increased the number of hydrogen bonds so that the membrane was more greatly swollen. Meanwhile, the simulations on the adsorption, diffusion and permeation predicted that the PBAT membrane had excellent separation performance for phenol. Besides MD simulation, the influences of feed concentration and temperature on pervaporation performance were also investigated by experiment. The results showed that the flux of each component increased with the feed concentration. This phenomenon was attributed to the preferential adsorption of phenol by the PBAT membrane, which resulted in large free volumes and cavities within the membrane, accelerating the diffusion of molecules. In addition, it was found that the optimal operating temperature was 333 K with the best separation performance. This study confirms that the biodegradable PBAT membrane is valuable for the recovery of high boiling point organic compounds (HBOCs) such as phenol.