Department of Chemical and Biomolecular Engineering
CHUNG, Tai-Shung Neal
Professor and Provost's Chair
PhD (Chem. Eng.) SUNY, 1981
MSc (Chem. Eng.) Natn’l Taiwan, 1977
BSc (Chem. Eng.) Chung-Yuan, 1973
Blk E4, 4 Engineering Drive 3, #05-37, Singapore 117576
Tel: (65) 6516 6645 Fax: (65) 6779 1936
My research focus on the development of superior performance polymeric membranes for various applications, such as Desalination and Water Reuse, Sustainable Energy and Pharmaceutical Separation, via the design of new materials and, the exploration and optimization of membrane fabrication protocols. In-depth studies on the characteristic of polymeric membranes and current membrane technologies have been conducted to understand their limitations and advantages. Hence, the integrated science and engineering that bridges polymer fundamentals and membrane technology have been revealed.
Membrane Science and Technology for Sustainable Energy Resources
Energy is a major global concern due to resource depletion and highly fluctuating oil prices. Among many energy alternatives, hydrogen, natural gas and biofuel are the three strategically important sustainable fuel sources for the foreseeable future. Therefore, the separation and purification of these 3 gases are of umpteen importance and it can be done by the following membrane technologies.
Membrane gas separation is an attractive alternative purification technique as compared to conventional processes as the process is rapid and more importantly, more capital and energy efficient. It is achieved primarily through solution-diffusion transport phenomena, driven by imposing a pressure gradient between upstream feeds and downstream permeates. Currently, we focus on the separation of O2/N2 for oxygen enrichment, H2/CO2 & CO2/H2 for hydrogen recovery and lastly CO2/CH4 & N2/CH4 for enhanced natural gas recovery.
Pervaporation, in its simplest form, is a combination of membrane permeation and evaporation. It is an emerging membrane technology for liquid separation as it has advantages of high selectivity, energy-efficiency and eco-friendliness for molecular-level liquid separation. Here in my team, we have molecularly designed new membranes for biofuel purification and solvent recycling via pervaporation. At present, our research targets include 1) development of mixed matrix materials and fundamentally investigate their formation property and 2) fabrication of multi-layer hollow fibers.
Membrane Science and Technology for Desalination & Water Reuse
Unusual climate change, rapid industrial growth, fast development of mega-size cities, and severe flooding and drought resulting from nature disasters have intensified the search for clean water across the world. To defuse the world’s fresh water crisis, improvement in current desalination technology and a more aggressive wastewater treatment and reuse strategy will be necessary. In my team, we concentrate on 2 emerging technologies that I believe will make significant headway to improve current desalination and wastewater recycling technologies as they have the advantages of simplicity, less fouling and most importantly, reduces the energy consumption.
Membrane distillation (MD) combines both membrane technology and evaporation processing in one unit. It involves the transportation of water vapor via temperature difference across the membrane. It offers the attractiveness of operating at atmosphere pressure and low temperatures (30 – 90°C) with the theoretical ability to achieve 100% salt rejection.
Forward Osmosis (FO) is the natural diffusion of water from a high to low concentration of water in the solution through a semi-permeable membrane. It does not required external pressure like conventional processes and it has less fouling too. Thus, it is consider as an energy-free device and also one with higher productivity.
Breakthroughs have been made to develop nanofiltration, high water flux and high salt rejection, hollow fiber membranes specifically for MD and FO via novel membrane materials and spinning technologies.
Membranes for Biopharmaceutical Syntheses and Separation
Pharmaceutical syntheses are often taken place in organic solvents through multiple steps of synthesis, multi-step separations and purifications have to be conducted in order to facilitate the reactions as well as to concentrate or separate small molecular weight (Mw) pharmaceutics and intermediates. The purpose of this project is to conduct fundamental research on using membrane technologies to facilitate biopharmaceutical syntheses and to separate and purify biopharmaceutical products in organic solvents. Two approaches are examined; one is using nano-filtration membranes to separate low Mw pharmaceutics and intermediates; the other is employing pervaporation technology to recycle waste organic solvents in biopharmaceutical syntheses.