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Title: SWITCHABLE POLARITY SOLVENTS AS DRAW SOLUTES FOR FORWARD OSMOSIS

Abstract

Switchable polarity solvents (SPS), mixtures of carbon dioxide, water, and tertiary amines, are presented as viable forward osmosis (FO) draw solutes allowing a novel SPS FO process. In this study substantial osmotic strengths of SPS are measured with freezing point osmometry and were demonstrated to induce competitive ?uxes at high salt concentrations on a laboratory-scale FO unit utilizing a ?at sheet cellulose triacetate (CTA) membrane. Under the experimental conditions the SPS degrades the CTA membrane; however experiments with polyamide reverse osmosis (RO) membranes display stability towards SPS. Once the draw is diluted the major fraction of the switchable polarity solvent can be mechanically separated from the puri?ed water after polar to nonpolar phase shift induced by introduction of 1 atm carbon dioxide to 1 atm of air or nitrogen with mild heating. Trace amounts of SPS can be removed from the separated water with RO in a process that avoids solution concentration polarization. The separated nonpolar phase can be regenerated to a full strength draw and recycled with the re-addition of 1 atm of carbon dioxide.

Authors:
; ; ;
Publication Date:
Research Org.:
Idaho National Laboratory (INL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1079632
Report Number(s):
INL/JOU-12-25275
DOE Contract Number:  
DE-AC07-05ID14517
Resource Type:
Journal Article
Resource Relation:
Journal Name: Desalination; Journal Volume: 312
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; desalination; forward osmosis; produced water; Solution Mining; switchable polarity material; switchable polarity solvent; Water Remediation

Citation Formats

Frederick F. Stewart, Mark L. Stone, Aaron D. Wilson, and Cathy Rae. SWITCHABLE POLARITY SOLVENTS AS DRAW SOLUTES FOR FORWARD OSMOSIS. United States: N. p., 2013. Web.
Frederick F. Stewart, Mark L. Stone, Aaron D. Wilson, & Cathy Rae. SWITCHABLE POLARITY SOLVENTS AS DRAW SOLUTES FOR FORWARD OSMOSIS. United States.
Frederick F. Stewart, Mark L. Stone, Aaron D. Wilson, and Cathy Rae. Fri . "SWITCHABLE POLARITY SOLVENTS AS DRAW SOLUTES FOR FORWARD OSMOSIS". United States.
@article{osti_1079632,
title = {SWITCHABLE POLARITY SOLVENTS AS DRAW SOLUTES FOR FORWARD OSMOSIS},
author = {Frederick F. Stewart and Mark L. Stone and Aaron D. Wilson and Cathy Rae},
abstractNote = {Switchable polarity solvents (SPS), mixtures of carbon dioxide, water, and tertiary amines, are presented as viable forward osmosis (FO) draw solutes allowing a novel SPS FO process. In this study substantial osmotic strengths of SPS are measured with freezing point osmometry and were demonstrated to induce competitive ?uxes at high salt concentrations on a laboratory-scale FO unit utilizing a ?at sheet cellulose triacetate (CTA) membrane. Under the experimental conditions the SPS degrades the CTA membrane; however experiments with polyamide reverse osmosis (RO) membranes display stability towards SPS. Once the draw is diluted the major fraction of the switchable polarity solvent can be mechanically separated from the puri?ed water after polar to nonpolar phase shift induced by introduction of 1 atm carbon dioxide to 1 atm of air or nitrogen with mild heating. Trace amounts of SPS can be removed from the separated water with RO in a process that avoids solution concentration polarization. The separated nonpolar phase can be regenerated to a full strength draw and recycled with the re-addition of 1 atm of carbon dioxide.},
doi = {},
journal = {Desalination},
number = ,
volume = 312,
place = {United States},
year = {Fri Mar 01 00:00:00 EST 2013},
month = {Fri Mar 01 00:00:00 EST 2013}
}