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Institute for Green Science

Awards

1999 Presidential Green Chemistry Challenge
Academic Award

Green Chemistry Challenge AwardTerry Collins
Department of Chemistry, Carnegie Mellon University
TAML® Oxidant Activators: General Activation of Hydrogen Peroxide for Green Chemistry

Twenty years of research by Professor Terry Collins at Carnegie Mellon University has led to the successful development of a series of environmentally friendly oxidant activators based on iron. These TAML® (tetraamido-macrocyclic ligand) activators catalyze the reactions of oxidants in general. Their activation properties with hydrogen peroxide in water are of greatest environmental significance. TAML® activators arise from a design process invented by Professor Collins which is complementary to that employed by Nature to produce powerful oxidizing enzymes. The activators promise extensive environmental benefits coupled with superior technical performance and significant cost savings across a broad-based segment of oxidation technology. Users of TAML® peroxide activators will range from huge primary extractive-processing industries to household consumers throughout the world. In laboratory tests, the Collins activators have shown this potential in the major industrial application of wood pulp delignification and in the broad-based consumer process of laundry cleaning.

Annually, bleached pulp has a global value of approximately $50 billion. The key to quality papermaking is the selective removal of lignin from the white fibrous polysaccharides, cellulose, and hemicellulose. Wood-pulp delignification has traditionally relied on chlorine-based processes that produce chlorinated pollutants. It has been clearly demonstrated that TAML® activators can provide the Pulp and Paper Industry (P&PI) with the first low-temperature hydrogen peroxide-based delignification technology for treating pulp. The new process moves the elemental balance of pulp delignification closer to what Nature employs for degrading lignin, a strategy reflected in the industry's recent development of totally chlorine free (TCF) bleaching procedures. TAML® activated peroxide delignification proceeds rapidly and efficiently at 50 °C indicating that minimal capital will be required to retrofit existing mills for its use. The new technology is more selective than any other TCF process and, except at low lignin content, is as selective as the current dominating delignification technology based on chlorine dioxide. These parameters show that the new technology can significantly reduce persistent pollutants associated with chlorine-containing delignifying agents by enabling the industry to use peroxide to remove the majority of lignin from kraft pulp more selectively and more rapidly.

In the laundry field of use, most household bleaches are based upon peroxide. Here, TAML® activators enable the most attractive dye transfer inhibition processes ever developed. Almost all the approximate 80 dyes used on commercial textiles are safe from TAML® activated peroxide while they are bound to a fabric. But in almost every case, should a dye molecule escape a fabric, the same TAML® activated peroxide will intercept and destroy it before it is able to transfer to other fabrics. This attribute and the improved stain removal properties of TAML® activated peroxide, offer significant commercial advantages for laundry products producers. In addition, the combined features translate to both direct and indirect environmental benefits by enabling laundering that replaces stoichiometric with catalytic procedures and that requires less water. Numerous other fields of use are anticipated; some are currently being developed including the use of TAML® peroxide activators for water disinfection.

From:
The Presidential Green Chemistry Challenge Awards Program
Summary of 1999 Award Entries and Recipients
United States Environmental Protection Agency
EPA744-R-00-001
March 2000

More information on the Presidential Green Chemistry Challenge Program is available at the EPA’s website.