Membrane Synthesis for Commercially Viable Osmotic Power Generation by Pressure Retarded Osmosis (PRO)

Abstract

Water and energy are crucial resources for humans. Current energy and water demands are on the rise and it is necessary to find new avenues to obtain these resources. Osmotic power is an increasingly well-studied form of energy. Our research is on focused on pressure retarded osmosis (PRO) because it is the most prominent way of generating osmotic energy. Past applications of PRO have largely ended in failure due to limitations of the membrane. Our research is focused on developing new membranes that can generate commercially viable osmotic power. The power generated from the PRO process can compensate for the high energy consumption in the desalination processes. In this project, we have successfully fabricated membranes that are strong (i.e., high maximum tensile stress and high burst pressure), possess high water permeability as well as high salt rejection of over 95% (i.e., low salt permeability) through direct phase inversion and interfacial polymerization. We have achieved a peak power density of 12 W/m2 which is higher than 3 W/m2. This shows that our membrane can generate commercially viable energy. We have outperformed the early membranes developed for power generation. PRO is especially applicable in Singapore which relies heavily on desalination for potable water. To the best of our knowledge, we have synthesized the strongest inner selective hollow fiber thin film composite PRO membrane.