(60b) Porous Polytetrafluoroethylene Supported Silicalite Nanosheet Laminated Membrane Volatile Fatty Acid Separation from Anaerobic Bioreaction Broth

Volatile fatty acids (VFAs) with C₂−C₆ short chains such as acetic, propionic, butyric, valeric, and caproic acids are products from anaerobic fermentation of a variety of organic wastes. These VFAs are important feed stocks for synthesizing many high-value chemicals and materials. However, the economic viability of such VFA production from wastes has been limited by their generally low yield and difficulty in separation and recovery from complex solutions containing dissolved salts and solid contents. This presentation discusses the fabrication of a highly hydrophobic, molecular sieve silicalite nanosheet membrane laminated on macroporous polytetrafluoroethylene (PTFE) film and experimental investigation on its performance in pervaporation (PV) separation of VFAs from the saline solutions. The silicalite nanosheet laminated membrane (SNLM) has been proven highly efficient and robust for PV desalination of high-concentration brines. In this work, we focus on the SNLM formation on the chemically, structurally, and thermally stable porous PTFE and demonstration of its extraordinary hydrophobicity and membrane stability for enhanced VFAs separation from the aggressive solutions. We will also investigate the effects of operating parameters on the PV membrane separation of VFAs, including the feed pH, operating temperature, and chemical compositions.