Green chelating agent

Akzo Nobel (Amsterdam; edlinks.chemengonline.com/6892-546) has commercialized a biodegradable chelating agent, Dissolvine GL, as a cost-effective, green alternative to the two most frequently used agents, ethylenediamineetetraacetic acid (EDTA) and nitrotriacetic acid (NTA). The product contains L-glutamic acid (from sugar, molasses, corn or rice), which is produced biochemically to yield the pure L isomer. The amino acid is then modified using a proprietary process to produce GLDA (glucamic acid diacetic acid). In addition to having similar metal chelation properties to alternatives, the GLDA is very soluble in water over a wide range of pH. At pH 1, for example, GLDA has a solubility of about 1 mol/L (35 wt.%) compared 0.1 wt.% for EDTA. This is significant for clean-in-place applications that use cleaning products formulated at low pH, says Akzo Nobel. GLDA is also thermally stable at temperatures above 300°C (compared to <150°C for EDTA and NTA), making it suitable for reducing the effects of "hard" water in boiler systems, says the firm.