期刊
ENERGY & ENVIRONMENTAL SCIENCE
卷 6, 期 4, 页码 1199-1210出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/c3ee23349a
关键词
-
资金
- Prime Minister's Office of Singapore via an initiative called The Enterprise Challenge [P00579/1273]
- Singapore Environment & Water Industry (EWI) Development Council [MEWR 621/06/166]
- Public Utilities Board of Singapore
A significant amount of energy stored in the form of salinity in seawater reverse osmosis (SWRO) brine can be harvested by a pressure retarded osmosis (PRO) process for power generation. The crucial performance-determining factor of the PRO process is the semi-permeable PRO membrane, which separates the SWRO brine from a lower salinity solution and sustains the salinity difference between the two solutions. However, accumulation of solutes in the support membrane, namely internal concentration polarization (ICP), significantly reduces the effective salinity difference and thus severely limits the efficiency of conventional PRO membranes. In this paper, we report the fabrication and optimization of thin-film nanofiber composite PRO (TNC-PRO) membranes with a unique support membrane structure (interconnected, low tortuousness and highly porous properties), aiming to facilitate mixing of accumulated solutes with a dilute feed stream and overcome the ICP problem. With such low structure parameter (S) value (150 mu m) nanofiber support membranes (NSMs), the optimum water permeability (A) and solute permeability (B) of the TNC-PRO membrane for power generation were determined to be 4.1 L m(-2) h(-1) bar(-1) and 1.74 L m(-2) h(-1) respectively. This highly efficient TNC-PRO membrane can achieve a power density of 15.2 W m(-2) and maximum energy recovery of 0.86 kW h m(-3), using synthetic brackish water (80 mM NaCl, pi = 3.92 bar) and seawater brine (1.06 M NaCl, pi = 51.8 bar) as feed and draw solution, respectively. For a more dilute synthetic river water (0.9 mM NaCl, pi = 0.045 bar) feed solution, the same membrane can achieve a higher power density of 21.3 W m(-2). The main performance limiting factors in PRO application such as ICP, External Concentration Polarization (ECP) and Reverse Solute Permeation (RSP) are quantified and their values are related to A, B and S values of TNC-PRO membranes.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据