Title: Solar Desalination Using Thermally Responsive Ionic Liquids Regenerated with a Photonic Heater

Abstract

Growing global water demand has brought desalination technologies to the forefront for freshwater production from nontraditional water sources. Among these, forward osmosis (FO) is a promising two-step desalination process (draw dilution and regeneration), but it is often overlooked due to the energy requirements associated with draw regeneration. To address this limiting factor, we demonstrate FO desalination using thermally responsive ionic liquids (ILs) that are regenerated using a renewable energy input, that is, solar heat. To efficiently harness sunlight, a simple photonic heater converts incoming irradiation into infrared wavelengths that are directly absorbed by IL-water mixtures, thereby inducing phase separation to yield clean water. This approach is markedly different as it uses radiative heating, a noncontact mode of heat transfer that couples to chemical functional groups within the IL for rapid energy transfer without a heat exchanger or secondary fluid. Overall, a solar-thermal separation efficiency of 50% is achieved under unconcentrated sunlight, which can be increased to 69% with the thermal design. Successful desalination of produced water from oil wells in Southern California highlights the potential of solar-powered IL-FO for energy-efficient and low-cost desalination of complex brines for beneficial water reuse.

Authors:

Haddad, Andrew Z.  ^[1];

• Search DOE PAGES for author "Haddad, Andrew Z."
• Search DOE PAGES for ORCID "0000-0002-9206-3505"

Menon, Akanksha K.  ^[1];

• Search DOE PAGES for author "Menon, Akanksha K."
• Search DOE PAGES for ORCID "0000-0003-1979-507X"

Kang, Hyungmook ^[2]; Urban, Jeffrey J.  ^[3];

• Search DOE PAGES for author "Urban, Jeffrey J."
• Search DOE PAGES for ORCID "0000-0002-6520-830X"

Prasher, Ravi S.  ^[4];

• Search DOE PAGES for author "Prasher, Ravi S."
• Search DOE PAGES for ORCID "0000-0002-3282-7147"

Kostecki, Robert ^[1]

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+ Show Author Affiliations

1. Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
2. Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States, Department of Mechanical Engineering, University of California, Berkeley, California 94720, United States
3. Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
4. Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States, Department of Mechanical Engineering, University of California, Berkeley, California 94720, United States

Publication Date:

Wed Feb 17 00:00:00 EST 2021

Research Org.:

Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office

OSTI Identifier:

1766107

Alternate Identifier(s):

OSTI ID: 1771967

Grant/Contract Number:  

AC02-05CH11231; 34324

Resource Type:

Published Article

Journal Name:

Environmental Science and Technology

Additional Journal Information:

Journal Name: Environmental Science and Technology Journal Volume: 55 Journal Issue: 5; Journal ID: ISSN 0013-936X

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Mixtures; salts; solvents; solution chemistry; ions