Argonne’s new electrodeionization process overcame several engineering challenges. Chemical engineer Paula Moon inspects the electrodeionization wafer stack after assembly.

Salt-removal method is enviro-friendly

Argonne has developed a new salt-removal process that is both cheaper and friendlier to the environment than the conventional industrial process.

Argonne's new “electrodeionization” (EDI) process could help reduce costs and toxic chemical wastes for the corn syrup industry and many others that remove salt at some point during manufacture. Corn syrup is a common ingredient in food products from fountain drinks to ketchup to breakfast cereal.

EDI uses 90 percent fewer chemicals than the conventional process. R&D magazine recognized the process with an R&D 100 Award.

Demonstrated in a Lafayette, Ind., pilot plant, the process successfully desalinated 2,000 gallons of dextrose syrup a day in a commercial corn wet milling plant.

Long-sought alternative
EDI could be the long-sought alternative to the conventional ion exchange process, which is costly and produces millions of tons of chemical waste yearly, according to Seth Snyder, section manager of chemical and biological technology in Argonne's Energy Systems Division.

“EDI costs half as much as conventional desalination, and generates only half the waste as well,” Snyder said. “It gives us the best of both worlds.”

Conventional salt removal is not an easy process. Corn syrup, for example, must be passed through 30-foot-tall columns of resin granules. The granules effectively remove the salt, but must be treated with acid and caustic base chemicals before they can be reused. The chemicals and salt remain behind, forming wastes that can pollute groundwater and threaten health.

Economically competitive option
Until now, no economically competitive alternative to the conventional method has been available. To address this problem, Argonne and its research partner EDSep Inc. jointly developed and tested the novel process based on EDI technology. The Mt. Prospect, Ill., company and Argonne have applied for the patents.

“The chemicals necessary for conventional desalination alone would have cost more than the entire EDI process,” EDSep’s President, Rathin Datta said. “Because EDI primarily uses electricity to drive the process, the use of hazardous chemicals is almost eliminated.”

EDSep is working closely with Argonne to commercialize the EDI process.

This research was sponsored by the Department of Energy's Office of Industrial Technologies. It is a component of the successful application of Argonne’s chemical technology and biotechnology work to develop products from renewable sources. These “bio-based products” reduce the national dependence on imported petroleum and improve the energy efficiency of U.S. industry. 

Other biotechnology research
Argonne’s Chemical and Biotechnology Section has also produced “green solvents”—biodegradable chemicals that replace toxic chlorinated solvents in applications such as engine degreasing and printing press cleaning. Argonne’s industrial partner, Vertec Biosolvents Inc. of Downers Grove, Ill., is developing commercial markets for these products based on Argonne and Vertec’s processes.

Other major biotechnology projects at Argonne include:

• The Biochip Technology Center, focusing on rapid detection of bioterrorist threats,
• The Structural Biology Center, working to determine the high-resolution structure of major molecules determined in the Human Genome Project, and
• The Functional Genomics Initiative, dedicated to understanding the inner workings of biological cells at the level of every gene and protein.

For more information, please contact Evelyn Brown.

Next: Solvent extraction process reduces wastes

Back to top