Grantee Research Project Results
2020 Progress Report: Portable Desalination Using Ocean and Solar Energy
EPA Grant Number: SU839910Title: Portable Desalination Using Ocean and Solar Energy
Investigators: Zuo, Lei
Current Investigators: Zuo, Lei , Mi, Jia , Capper, Joseph , Chen, Shuo , Jones, Erin , Lane, Jimmy , Vencill, Ethan , O'Donnel, Dana
Institution: Virginia Tech
EPA Project Officer: Page, Angela
Phase: I
Project Period: October 1, 2019 through September 30, 2020 (Extended to August 31, 2021)
Project Period Covered by this Report: October 1, 2019 through September 30,2020
Project Amount: $25,000
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2019) RFA Text | Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources
Objective:
The purpose of project is to develop a portable desalination system using marine renewable energy, shown in Figure 1. The proposed consists of two modules: wave energy converter module and reverse osmosis (RO) desalination module. In order to fit the portable design concept, a two-body selfreactive point-absorber wave energy converter will be developed to capture the wave energy and drive the highpressure pump. There is one floating buoy and one submerged heave plate which can achieve self-reactive between the two bodies. A RO module will be adapted with an accumulator to stabilize the system pressure under fluctuated wave conditions. The proposed system can fill a market void of portable desalination system which can be used for isolated coastal or salt lake communities and also disaster relieve scenarios. In phase I of this project, different renewable energy resources have been evaluated to determine the best energy source for powering the desalination system. A prototype of self-reactive two-body point absorber wave energy converter has been built and tested in the wave tank. A RO desalination system has been demonstrated driven by a double-acting highpressure piston pump.
Figure 1. Portable desalination using ocean wave energy
Progress Summary:
During the Phase I of this project, a portable desalination system driven by ocean waves has been proposed and evaluated. A two-body self-reactive point-absorber wave energy converter has been integrated, tested and characterized, as shown in Figure 2 and Figure 3. A RO desalination system driven by high-pressure piston pump has been demonstrated and tested with off-the-shelf components, as shown in Figure 4. The system pressure can reach to about 50 bar and the concentration of the produced freshwater is lower than 500 mg/L. It should be noted that, only preliminary test driven by hand at home was tested because of pandemic lockdown. The preliminary test results show the proposed RO desalination system driven by high-pressure piston pump without electricity could be realized in the real condition. All the components used in the preliminary test are commercially available off-the-shelf components, which is good for future commercialization and mass production. Summary of the Phase I includes:
- Considering the energy efficiency and small-scale operation, RO is the best desalination technology;
- Regarding the energy density, ocean wave energy (1-40kW/m) is much larger than solar energy (0.1-1kW/ m2 ) which is much more applicable to realize the initial portable desalination system concept;
- A portable two-body self-reactive pointabsorber wave energy converter (diameter 0.75m) has been fabricated, tested and characterized in the wave tank;
- A RO desalination system driven by a double-acting high-pressure piston pump has been demonstrated and tested with off-theshelf components.
Figure 2. Test set-up of the wave energy converter
Figure 3. Performance under different conditions
Figure 4. Preliminary test of the RO system
Future Activities:
In the next report period, we plan to integrate the wave energy converter and RO system together, to illustrate the overall concept. Future research directions in the coming Phase II period (if could be awarded) are as follows:
- The overall waves-to-water modelling from ocean wave energy to the desalinated freshwater needs to be complete to understand the energy-water nexus;
- The overall waves-to-water prototype with two sub-systems (wave energy converter and RO desalination) needs to be integrated together;
- System level parameters optimization needs to be investigated to improve the system efficiency and enhance the performance;
- The potential market and customer requirements should be investigated to guide the system design and prepare for future commercialization.
Journal Articles:
No journal articles submitted with this report: View all 3 publications for this projectSupplemental Keywords:
Renewable energy, portable desalination, point-absorber, reverse osmosis, energy-water nexusProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.