Highly Efficient Removal of Mercury from Industrial FlueGas

This proposal identifies a technology that potentially reduces volatile metal mercury emissions by ~95% from coal fired utilities. Frontier GeoSciences, Inc. has discovered a method of removing Hg by chemically modifying scrubber water with a proprietary polymer (FGS-MCX). Scrubber water naturally removes Hg species that are water soluble (e.g. MMHg and HgCl2), but this proposal focuses on Hg0. The complexed Hg easily separates from the scrubber water allowing the recycling of the scrubber water without additional treatment for toxic metals. FGS-MCX is a wet scrubber amendement that requires no additional equipment, therefore reducing capital and implementation costs. The resulting solid passes all required Toxicity Characteristic Leaching Procedure requirements. Mercury is recognized as a Hazardous Air Pollutant and Persistent Bioaccumulative Toxic, and its pollution through air emissions is regulated by the 2005 EPA Clean Air Mercury Rule. The Clean Air Mercury Rule regulates Hg emissions from new and existing coal-fired power plants by establishing a maximum national emissions level and imposing a cap-and-trade system. In an ideal situation, mercury would not be in the raw materials used; unfortunately this is not currently feasible, and the easiest locations for mercury capture are flue gas dischargers. Previous research on FGS-MCX has shown that it successfully removes ~95% Hg0 from a contaminated N2 gas stream and >86% removal of Hg) from a simulated flue gas stream when tested in an impinger/bubbler system. The optimal dosing amount of FGS-MCX, the effects of scrubber water volume and pH and the ability to recycle materials have already been studied. This technology to real-scale working Venturi wet scrubber system in the presence of common matrix components of typical scrubber water, such as for a flue gas desulfurization unit. Other goals include establishing the length of time the scrubber water and FGS-MCX can be recycled before exhaustion, and maximizing the separation efficiency of the FGS-MCX floc from scrubber water. Finally, Hg0 removal from natural gas, by the FGS-MCX amendment, will be demonstrated as a potential application for the petroleum industry. As there is no capital equipment expenditure required, it is envisaged that the technology will at the minimum, pay for itself through the production of salable mercury credits.