Abstract
Reverse osmosis (RO) is a desalination technique that is commonly preferred because of its low energy consumption. In this paper, an innovative, thermally powered RO desalination process is presented. This new thermo-hydraulic process uses solar thermal energy in order to realize the pressurization of the saltwater beyond its osmotic pressure to allow its desalination. This pressurization is enabled thanks to a piston or a membrane set in motion in a reservoir by a working fluid that follows a thermodynamic cycle similar to an Organic Rankine Cycle. In this cycle, the evaporator is heated by low-grade heat, such as the one delivered by flat-plate solar collectors, while the condenser is cooled by the saltwater to be treated. Such an installation, designed for small-scale (1 to 10 m3·day−1) brackish water desalination, should enable an average daily production of 500 L of drinkable water per m² of solar collectors with a specific thermal energy consumption of about 6 kWhth·m−3. A dynamic modeling of the whole process has been developed in order to study its dynamic cyclic operating behavior under variable solar thermal power, to optimize its design, and to maximize its performances. This paper presents the preliminary performance results of such a solar-driven desalination process.
Highlights
Growth of the demand in seawater and brackish water desalination over the past few years has been motivated by increasing water stress in an increasing number of countries
Simulation parameters were determined from a previous sizing, sizing, and simulations were made under static working conditions
Powering an Reverse osmosis (RO) device by low-temperature heat through an integrated thermodynamic engine cycle without energy storage can lead to drastic reduction of installation, maintenance, and operating costs in comparison to current implemented PV-operated RO desalination plants
Summary
Growth of the demand in seawater and brackish water desalination over the past few years has been motivated by increasing water stress in an increasing number of countries. Even if a major part of desalination systems is powered by fossil energies, desalination systems driven by renewable energies are well-known and available on the market. Solar desalination is interesting, considering how the most water-lacking areas are coastal and have an important sun resource. Solar-driven desalination can be led in two different ways: distillation or membrane separation. The water is evaporated by the solar heat. The most current distillation-based technologies are the multi-effect distillation (MED) and the multi-stage flash distillation (MSF). Those processes have a total specific primary energy consumption (SEC) commonly ranging between 30 and
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
