Thin-film Composite Hollow Fibre Membrane Has Been Developed for Pressure Retarded Osmosis

A new thin-film composite hollow fibre membrane has been developed for pressure retarded osmosis. High power density can be achieved using seawater and wastewater brines, demonstrating that this hollow fibre membrane has potential for PRO in harvesting salinity gradient energy. A new, specially designed pressure retarded osmosis (PRO) hollow fibre membrane has been developed by researchers at Nanyang Technological University in Singapore. The membrane has been applied in the PRO process to demonstrate its potential for power generation. The membrane fabrication method is similar to that used for making thin-film composite (TFC) forward osmosis hollow fibre membranes. Further optimisation and improvement have led to a new type of TFC hollow fibre membrane, with much greater mechanical strength in addition to its excellent separation properties and high water flux. The researchers say that this PRO hollow fibre membrane has superior power density to all other PRO membranes reported in the open literature. A power density as high as 10.6 W/m2 can be achieved using seawater brine and wastewater brine, which suggests that the newly developed PRO hollow fibre membrane has great potential to be applied in PRO processes to harvest salinity gradient energy. A higher pressure is preferred, as it results in a higher power density – pressures of 12 bar may be optimal for seawater as the high salinity stream. This can be realised through a reduced fibre dimension. The researchers are now working to further optimise the membrane structure. Source: workingwithwater.filtsep.com