TY - JOUR
T1 - Assessing the current state of commercially available membranes and spacers for energy production with pressure retarded osmosis
AU - Hickenbottom, Kerri L.
AU - Vanneste, Johan
AU - Elimelech, Menachem
AU - Cath, Tzahi Y.
N1 - Funding Information: The authors would like to thank DOE/ARPA-e (Award No. DE-AR0000306 ) and EPA-STAR (Fellowship No. 91746401-0 ) for the financial support of this research. Special thanks to Mr. John Bush for his technical support with SEM imaging, to Mr. Tani Cath and Mr. Mike Veres for their technical support constructing the test system, and to HTI and Oasys Water for providing membranes and technical support. Publisher Copyright: © 2015 Elsevier B.V.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - Pressure retarded osmosis (PRO) is an osmotically driven membrane process that utilizes the energy of mixing between streams of high and low chemical potential to generate electrical energy. High power density of a PRO membrane is essential to maximize process efficiency and minimize the capital and operating costs. Thus, robust PRO membranes that can support high pressure and have high water flux, low reverse salt flux, low structural parameter, and a good membrane support structure are needed. In this study, four commercial forward osmosis (FO) membranes for use in PRO were compared. The effect of operating pressures, membrane spacers (type, orientation, and arrangement), and flow velocities on process performance were investigated. A thin film composite polyamide membrane from Hydration Technology Innovations was found to be the most robust and selective membrane. Compared to other spacer configurations, the use of unique feed channel spacer orientations was found to increase PRO power density by up to 46%, yielding a power density of 22.6 W/m2 (3 M NaCl draw solution and 4.1 MPa hydraulic pressure). However, membrane deformation was observed when operating pressures exceeded 3.5 MPa. The use of unique spacers coupled with decreased draw solution cross-flow velocities was found to increase PRO process efficiency.
AB - Pressure retarded osmosis (PRO) is an osmotically driven membrane process that utilizes the energy of mixing between streams of high and low chemical potential to generate electrical energy. High power density of a PRO membrane is essential to maximize process efficiency and minimize the capital and operating costs. Thus, robust PRO membranes that can support high pressure and have high water flux, low reverse salt flux, low structural parameter, and a good membrane support structure are needed. In this study, four commercial forward osmosis (FO) membranes for use in PRO were compared. The effect of operating pressures, membrane spacers (type, orientation, and arrangement), and flow velocities on process performance were investigated. A thin film composite polyamide membrane from Hydration Technology Innovations was found to be the most robust and selective membrane. Compared to other spacer configurations, the use of unique feed channel spacer orientations was found to increase PRO power density by up to 46%, yielding a power density of 22.6 W/m2 (3 M NaCl draw solution and 4.1 MPa hydraulic pressure). However, membrane deformation was observed when operating pressures exceeded 3.5 MPa. The use of unique spacers coupled with decreased draw solution cross-flow velocities was found to increase PRO process efficiency.
KW - Energy-water nexus
KW - Membrane integrity
KW - Osmotic power
KW - Power density
KW - Pressure retarded osmosis
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U2 - 10.1016/j.desal.2015.09.029
DO - 10.1016/j.desal.2015.09.029
M3 - Article
SN - 0011-9164
VL - 389
SP - 108
EP - 118
JO - Desalination
JF - Desalination
ER -