Affordable, Large-Scale Manufacturing of High Surface Area Iron Powder

Contaminated groundwater containing trichloroethylene and similar halogenated hydrocarbons poses a large-scale environmental challenge. Existing treatment methods are imperfect in that they are slow, expensive, fail to treat the full spectrum of groundwater contaminants, and sometimes produce even more toxic partially chlorinated chemical intermediaries. In the past decade, techniques have emerged to more effectively dechlorinate the toxic compounds in these contaminated sites. A particularly promising remediation system uses palladized iron as a reducing agent. Prior work has shown that these bimetallic powders have proven to be effective for rapidly enabling the dechlorination of these groundwater contaminants into relatively benign saturated hydrocarbons and metal salts. This surface catalyzed reaction operates fastest and with optimum volumetric efficiency when very small powders, with high surface areas, are used. Despite the market need, there is no existing low-cost source for these high surface area iron powders. To address this large market opportunity, OnMaterials, LLC, in a joint development program with ARCADIS, has performed preliminary experiments to make and test these enabling materials. These bench-scale trials used new synthesis routes that, if successfully developed, are capable of producing large quantities of relatively low-cost iron powder. Specifically, this work has produced small quantities of very high surface area (> 20 m2/g) iron colloids and larger quantities of sub-micrometer iron (surface area > 2 m2/g) suspensions. These powders then were coated with palladium and successfully used to dechlorinate hydrocarbons in a laboratory environment. The reaction kinetics of the palladized high surface area iron powders were 100¿150 times those of conventional granular iron filing remediation systems. This Phase I research project will extend this work to further develop the system and demonstrate a low-cost procedure that when commercialized, can produce the needed multi-ton quantities of sub-micrometer and nanocrystalline iron powders at costs of about $50 per kilogram. The availability of these low-cost powders will enable a cost-effective and rapid protocol to help solve a widespread environmental problem. When fully implemented, the concept will provide multi-million dollar cost savings to both government agencies and industrial entities.