Seminar: Biomimetic Systems for Membranes and Waste-to-Energy - Dr. Yen Wah Tong, Department of Chemical and Biomolecular Engineering, National University of Singapore

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WHAT: Seminar of Dr. Yen Wah Tong, Department of Chemical and Biomolecular Engineering, National University of Singapore
WHEN: 10 – 11 am, August 3, 2016
WHERE: Farrall Hall, Room 208
SEMINAR TITLE: Biomimetic Systems for Membranes and Waste-to-Energy
ABSTRACT:
Our lab has been studying materials and systems that mimic biology and nature for various applications, ranging from biomedical engineering to water purification, and from bioenergy to waste treatment. The goal is to learn from nature, using what nature has provided and adapting it to be more robust and scalable for engineering purposes. In this talk, two areas of recent interest will be presented, firstly in the field of membranes for water purification, and then in the field of managing organic wastes.
For water purification or desalination, Aquaporin-incorporated biomimetic membranes is very interesting as it has been estimated that the permeability of an aquaporin Z (AqpZ) reconstituted biomimetic membrane is 167 m/s/bar, which is by two orders of magnitude greater than the commercial polymeric membranes. However, limitations of the biomimetic membrane lie in that the ultrathin biomimetic bilayers are too fragile to withstand high hydraulic or osmotic pressure in the water purification application. The objective of our work is to design and fabricate aquaporin embedded membranes with excellent water purification performance. We have studied the mechanism of water transport through membrane-embedded aquaporin Z and established a relationship between membrane tension and osmotic permeability of an amphiphilic block copolymer bilayers. Moreover, we have developed several innovative yet simple and easy-to-implement methods to incorporate water-channel proteins into pre-fabricated membranes to develop advanced membrane materials for purifying water at low pressures and low energy. The biomimetic membrane exhibits high water permeability as well as high salt rejection during forward osmosis, while the AqpZ-vesicle imprinted membrane exhibits high mechanical strength and stability during nanofiltration process.
For the second part, technologies for waste treatment and conversion to energy have been around for more than 50 years. In particular, the most widespread and commercially viable process is anaerobic digestion of organic matter into biomethane, while gasification of biomass to hydrogen and syngas has also been commercialized in the last 10 years. However, these technologies and industries are almost always centralized and are of very large scales for the purpose of economies-of-scale. The scientific challenge and technological research is thus in modularizing and down-translating these processes, to enable them to be operated in a modular manner within a megacity such as Singapore and Shanghai, and to adapt them to a manageable urban system as potential distributed energy sources. In addition to enabling a local material and mass cycle to be closed loop, it also minimizes the need for transportation of wastes to centralized facilities, which is one of the major energy consumption activities that has not always been accounted for. In our programme, we are studying a hybrid waste-to-energy system comprising a compact anaerobic digester and a biomass gasification system for converting municipal solid wastes to energy.
ABOUT THE SPEAKER:
Associate Professor Yen Wah Tong joined the Department of Chemical and Biomolecular Engineering at the NUS in 2001. His research started with biomaterials based on peptide-amphiphile hydrogels for tissue engineering of the liver and brain together with biomolecule delivery. The major focus of his Biomimetic Materials and Systems Laboratory is thus on applying biomimetic principles for various applications, including membranes, scaffolds and processes. Recently, his group has expanded research into bioenergy using biomass wastes and municipal solid wastes, converting these into renewable fuels and chemicals. Prof Tong is currently the Assistant Dean for Research in the Faculty of Engineering at NUS. He is also the co-Programme Director for an NRF CREATE programme with Shanghai Jiaotong University “Energy and Environmental Sustainability Solutions for Megacities”.

Event Date/Time: 
Wednesday, August 3, 2016 - 10:00am to 11:00am
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Event Location: 
208 Farrall Hall