Grantee Research Project Results
Final Report: Cost Effective Seawater Desalination with ICP Element Arrays
EPA Contract Number: EPD12026Title: Cost Effective Seawater Desalination with ICP Element Arrays
Investigators: Kim, Sung-Jae
Small Business: Okeanos Technologies, LLC
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2012 through August 31, 2012
Project Amount: $79,738
RFA: Small Business Innovation Research (SBIR) - Phase I (2012) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Drinking Water Treatment and Monitoring
Description:
Lack of fresh water hinders economic development, devastates human health, leads to environmental degradation and foments political instability. The primary problem is the over-reliance on quasi-renewable, environmentally vulnerable surface water sources. Brackish and seawaters provide a solution to the impending water crisis, but current technologies do not allow for desalination in a cost-effective manner. Okeanos Technologies believes that a breakthrough in desalination efficiency and cost will require taking the problem from the macroscale, where volumes of water are pushed with brute force through large cylinders and membranes, to the micro, and even the nanoscale, where the physics are more elegant and efficient. The purpose of the Phase I SBIR project was to validate the potential for an innovative clean-energy microdevice to desalinate seawater in an efficient, cost-effective manner. Okeanos' device is called the WaterChipTM. It uses microchannels, micro/nanoelectrodes and a novel physical process to desalinate water using an electrochemical phenomena observable only in nanoscale called Ion Concentration Polarization (ICP). Specifically, Okeanos is employing a type of ICP that has never before been applied to the problem of desalination. Water travels through a microchannel, and is subjected to an Ion Exclusion Zone (IEZ) at a point in the channel where it bifurcates into a brine and product water stream. Establishing an IEZ without the use of membranes or ion-selective matrices, Okeanos' variant of ICP enables desalination in a manner that is reliant on electron transfer kinetics rather than ionic transfer kinetics, and as a result is immensely more efficient than existing technologies, including basic ICP. Massively paralleled, Okeanos' WaterChipsTM will comprise systems providing substantial water flows at greater than 10-fold operational savings relative to modern-day systems. The extreme energy efficiency will enable off-grid operations such that desalination can take place where it is needed, no longer tied to today’s dirty (coal-fired power) electrical grid and environmentally destructive centralized fresh aquifer distribution infrastructures, and will contribute towards alleviation of impending environmental, economic, political and human health-related crises.
Summary/Accomplishments (Outputs/Outcomes):
The specific aims of this project were to: demonstrate that Okeanos' ICP WaterChipTM devices were capable of efficient and cost-effective seawater desalination; optimize the basic element design for simplex operation; demonstrate parallel element design/operation; and draft a final massively paralleled design, including concept drawings, plans, subcontractors and vendors in preparation for Phase II and for efficient mass production. This work was a success with respect to each of these aims. Okeanos demonstrated that the devices were capable of desalting a phosphate buffer saline solution, producing adequate microscale flow rates per element using nanoamperes of current. Okeanos next moved to artificial seawater, and then natural seawater, demonstrating the same results. Desalination was monitored using BODIPY2 anionic tracer, a cationic tracer and through the measurement of electrical conductance using a novel microfluidics measurement device that Okeanos engineered specifically for this purpose. Waters spiked with the tracers showed deflection of both tracers into the brine stream. Conductance measurements along the microchannels proved that desalination was taking place. Whereas feedstock conductance levels were high, these levels dropped significantly at the IEZ. The company showed that the efficiency of desalination was a function of the strength of the IEZ field and the flow rate of the feedstock. Elements of the simplex design were optimized with respect to electrode configuration and basic operating parameters. Okeanos operated simplex devices in parallel, as has been accomplished before with other solution types (e.g., biomolecular), demonstrating that the devices are easily scalable. The company drafted an innovative design that replaces the microchannel with other microstructures that will enable Okeanos to massively parallelize the elements to achieve mL/min flow rates at the submodule level and L/min flow rates at the modular level.
Conclusions:
The next steps are to build prototype submodules, assemble them into prototype modules, validate their performance and incorporate commercialization partners to build prototype arrays comprised of these modules for field testing and eventual market penetration.
Supplemental Keywords:
seawater, desalination, ion concentration polarization, ICPSBIR Phase II:
Cost Effective Seawater Desalination with FICP Element Arrays | Final ReportThe 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.