This project addresses one of the world's major opportunities - the generation of potable water from sea and brackish water. Conventional high-energy processes for generating desalinated water include reverse osmosis (RO) which is a membrane based technique that requires high pressure, and thermal distillations such as Multi Stage Flash (MSF) and Multiple Effect Desalination (MED) where the brine is distilled to generate pure water. These methods have their limitations, and the development of the next generation of water purification technology is of great importance for generating soft water for public consumption to a range of industrial applications such as using brackish water for industrial cooling and the treatment of produced water from oil and gas production via fracking. Membrane distillation (MD) is a thermal evaporative process that vaporizes water through a membrane to generate pure water. It offers several advantages over traditional methods mentioned above. These include low temperature operation (60-90C) where industrial waste heat as well as solar energy can be used to desalinate water. The objective of this project is develop carbon nanotube based high performance membranes that can efficiently desalinate water at low temperature via MD. The resulting materials can be used of generate energy and treat saline or contaminated water in a cost effective and efficient manner.
The objective of this project is to utilize nano carbons (NC) to create breakthrough membrane properties for desalination via membrane distillation (MD). In MD, a hydrophobic porous membrane separates a hot salt water feed and a cold permeate stream. As the heated brine passes on the membrane, it is partially transformed to water vapor. The hydrophobicity of the membrane prevents the aqueous solution from entering the pores. However, freed from hydrogen bonding the water vapor passes through and is condensed on the permeate side of the membrane. The novel membrane referred to as NC immobilized membranes (NCIM) will be developed by immobilizing NCs into membrane pores where they will serve as molecular transporters and sorbents, thus providing additional pathways for water transport. This project will develop new technology and insight into the optimum process for functionalizing NC for water vapor transport as well as the incorporation of NC in membrane structures for desalination. The project will also real-world applications for power plants by emphasizing waste heat utilization and specific waste water streams encountered in that industry.
