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Astani CEE Department Seminar
Tue, Mar 04, 2014 @ 10:00 AM - 11:00 AM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Ngai Yin Yip, Yale University
Talk Title: Harnessing Natural Salinity Gradients for Sustainable Power Generation with Pressure Retarded Osmosis
Abstract: The development of alternative power sources is necessary to enable a global shift to a sustainable energy future. Pressure retarded osmosis (PRO) can produce renewable energy from natural salinity gradients by harvesting the free energy of mixing released when fresh river water or brackish water combines with seawater. This presentation will discuss the potential of sustainable power generation with natural salinity gradients, the recent membrane advancements toward realization of the technology, and the challenges that can hinder the implementation of PRO energy production. Firstly, a thermodynamic and energy analysis of PRO is presented to identify the intrinsic limitations and determine the efficiency of the process. The findings are then employed to assess the global potential of power generation with natural salinity gradients. In the second part of the study, the fabrication of thin-film composite membranes capable of achieving high performance in PRO is demonstrated. By thoughtful selection of the fabrication conditions to methodically suppress the detrimental effects that limit productivity, the hand-cast membranes advanced the achievable power densities to ~10 W/m2, twice the benchmark necessary for the technology to be cost-effective. Lastly, the detrimental impact of membrane fouling in PRO is examined and the cleaning efficiency of a quick, chemical-free osmotic backwash is evaluated. The fouling phenomenon and cleaning protocol were systematically analyzed and the implications for PRO power generation with natural salinity gradients are discussed.
Biography: Ngai Yin Yip is a doctoral student in the Department of Chemical and Environmental Engineering at Yale University. He received his bachelor's degree in Environmental and Civil Engineering (First Class Honors) from Nanyang Technological University, Singapore. His dissertation work focuses on novel membrane technologies for the sustainable production of energy and water. He received the ACS Environmental Chemistry Graduate Student Award in 2011 and the C. Ellen Gonter Best Paper Award from ACS in 2013.
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans
