Final Report: Regenerative Capacitive Electro-Desalination System (RECED)

EPA Contract Number: EPD15034
Title: Regenerative Capacitive Electro-Desalination System (RECED)
Investigators: Kolessov, Alex
Small Business: Physical Optics Corporation
EPA Contact: Manager, SBIR Program
Phase: I
Project Period: September 1, 2015 through February 29, 2016
Project Amount: $99,993
RFA: Small Business Innovation Research (SBIR) - Phase I (2015) RFA Text |  Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Water


The U.S. Environmental Protection Agency (EPA) Office of Water (OW) is seeking innovative technologies to improve the performance and reliability of small drinking water systems. In response, Physical Optics Corporation (POC) is developing a novel Regenerative Capacitive Electro-Desalination System (RECED), to enable the use of reduced-quality water sources, such as weakly saline brackish water, or even ocean- and seawater, as part of the drinking water system’s intake. This will provide much needed water source diversification to small-size drinking water systems, eliminating their sole dependency on the locally available ground or surface freshwater supply. The system is based on the recent development at POC of a unique, man-portable desalinator unit that demonstrated efficient, electrically driven desalination of brackish water and seawater, producing excellent quality drinking water output, at salinity levels below 250 ppm total dissolved solids (TDS). With the continued development of this new technology, POC will not only address the EPA need for better performing small drinking systems, but will enter a multi-billion dollar desalination system market that has experienced significant growth in recent years due to the continuing lack of freshwater resources worldwide. In RECED, POC is implementing a series of innovative technical solutions, which include using commercially available, non-degrading, high-performance nano-materials that guarantee years long continuous operation, with minimal maintenance requirements. Another technological innovation is the use of energy-saving, regenerative operating principle that allows a substantial degree of energy recovery during the desalination cycle, thus, reducing the overall power budget. The new system, lacking the high-pressure components of conventional reverse osmosis (RO) units, is cheaper, has a smaller footprint, and is easier to install and use. Its operation is automatic and self-sustainable, with higher uptime and shorter maintenance downtime, providing improved performance and reliability over current water treatment plants. RECED technology also offers significant advantages over the thermal desalination approach, especially when applied to the smaller, community-size installations of small drinking water systems.

Summary/Accomplishments (Outputs/Outcomes):

The following summarizes the work performed in Phase I:

  • Designed and constructed a multi-cell prototype to evaluate electrode performance, design cycles for continuous operation, and establish the feasibility of the RECED system.
  • Performed desalination experiments using the prototype system. The power consumption and recovery from desalination and regeneration cycles, respectively, was quantified. Additionally, a water sample was desalinated from above 35,000 ppm TDS to below 250 ppm TDS.
  • The results from experiments were used to establish design constraints for a full-scale system. It was also used to determine the number of electrodes needed, which helped us estimate the final size of the system at 20 ft3, accounting for pumps and reservoirs.
  • Utilizing the results from experiments, a system architecture for a full-scale, multi-stage RECED system was designed. The system architecture was accompanied by a design for controlling the operation of the system and managing desalination and regeneration cycles.
  • Established contact with vendors for essential materials, as well as a consulting company that is a major player in the water treatment field and can connect POC with potential end-users and provide useful feedback for system design.
  • Conducted a market analysis for commercialization with the help of Foresight Science & Technology. Performed cost-estimate analyses in order to plan for and establish a robust commercialization strategy for the RECED technology.


In Phase I, POC demonstrated the feasibility of RECED by building a benchtop test prototype and performing a series of experiments. We were able to demonstrate desalination of a water sample from 35,000 ppm TDS down to below 250 ppm TDS using a relatively small power budget. Based on the power consumption of the Phase I prototype desalination cells, operating with no energy recovery, we were able to estimate the energy necessary to desalinate 10,000 L of seawater, enough to supply 500 people for one day. With optimizations, including capturing energy from regenerating cells, we estimate that this figure can easily be improved to a level that makes the power consumption of RECED equal or better than state of the art desalination systems. To our knowledge, no other technology is currently available to deliver the mix of high throughput, energy efficiency, and low cost, which is potentially offered by RECED. Because of its demonstrably superior performance, the new system, once fully developed, can potentially capture a share of the market that is addressed today by osmotic desalination devices. Due to its scalability, the technology is not only relevant for deployment within community-sized, “very small” drinking water systems, but can also be applied to the development of smaller-sized desalination devices used by outdoorsmen, sailors, first responders and emergency personnel, etc.


POC has developed a strong commercialization strategy over the past few years. This strategy involves partnering with major companies in a particular market and providing them with technology that they cannot get elsewhere and that fits within their portfolio and business models, while using their manufacturing facilities and established sales and distribution networks to sell our products in their markets, with POC playing the role of the technology provider, through licensing or other means. POC is taking the same approach with RECED technology.

The commercialization efforts began with finding suppliers for the most critical component of RECED as well as beginning cost analysis for prototype production. We established contact with Foresight Science and Technology (Foresight) to discuss the scale and goals of RECED, so that Foresight could perform market analysis and market research, as well as begin searching for commercialization partners. Additionally, POC pursued a relationship with a major consultant in the water treatment industry. Through this relationship, POC will be able to establish new contacts with potential end users of RECED and gain feedback during the development process. Additionally, this company has helped POC choose specific market segments to target, which have the best chance of seeing significant adoption of the RECED technology. All of these activities fit into POC’s overall commercialization strategy for RECED which involves (1) working with the end-users of the RECED desalinator so that Phase II efforts focus on building a working prototype that can immediately be transitioned to commercial systems in Phase III; (2) investigating and identifying one or two market segments in which the RECED system can be directly applied with little modification; and (3) planning modifications and deliverable products to optimize the process for each targeted market segment. This strategy has proven successful in securing follow-on funding to commercialize technology based on POC’s prior SBIR projects.