|Top: RW-EDI stack. Bottom: Close-up of a single cell. Water splitting provides ions that continuously regenerate the ion exchange resin and enables electrochemical solution pH control. Source: Argonne/Nalco. Click to enlarge.|
Argonne National Laboratory and Nalco Company have reached a licensing agreement for a resin wafer electrodeionization (RW-EDI) technology. RW-EDI combines features of ion exchange and electrodialysis into an energy-efficient process for removing dissolved salts or recovering charged products without the use of regenerant chemicals.
RW-EDI has many potential uses including direct production and separation of products, product purification, desalination, salt waste recovery, and water recycling. Argonne National Laboratory received R&D 100 Awards in 2002 and 2006 for developing the technology and has completed successful pilot tests.
Argonne and Nalco have been involved in two DOE-funded research projects jointly developing this versatile RW-EDI technology. These projects have already demonstrated advantages in impaired water purification and in capture of CO2 from air. (In the CO2 application, the RW-EDI platform uses pH changes to adsorb and desorb CO2 from flue gas at atmospheric pressure, without energy-intensive, costly processes such as heating or a vacuum. It uses the enzyme carbonic anhydrase to drive the kinetics.)
Another application for Argonne’s patented technology is bioprocessing. Conventional bioprocessing technologies, such as those used to produce organic acids, require significant capital expenditures on energy-intensive steps to recover these products and generate large waste streams. Argonne’s technology allows for the continuous removal of charged products such as organic acids from aqueous process streams and eliminates the requirement to continuously add neutralizing agents, avoiding resulting waste stream.
We started our RW-EDI technology partnership with Argonne by advancing the use of this technology to allow impaired water to be used as cooling water in coal-based power plants. We expanded this collaboration through our ongoing ARPA-E funded effort to evaluate the technology for the energy efficient removal of CO2 from coal flue gas. We look forward to extending this partnership into many other areas of importance to our customers.—Cathy Doucette, Nalco Global Technology Leader
Argonne’s resin wafer technology is made from commercially available materials. By controlling dimensions, composition, porosity and conductivity, the resin wafer technology can be easily adapted to a target product. With the license in place, Nalco and Argonne will design and develop platforms to help customers integrate the clean technology into their manufacturing processes.
Funding for this technology was provided by DOE’s offices of Fossil Energy, Biomass and Industrial Technologies.