Superfund Research Program
On Site Mercury Remediation via Activated Fly Ash
Project Leader: Kaspars Krutkramelis
Grant Number: R43ES024620
Funding Period: Phase I: July 2014 – February 2016
Coal-fired power plants and burners are vital drivers of the U.S. economy-but they unfortunately produce substantial amounts of mercury (Hg) that are seriously harmful to human health, particularly linked to damages of the nervous system. Healthcare costs due to Hg exposure are estimated to be in the billions of dollars annually. New mercury-emission regulations (effective 2015) set a strict Hg cap of 1.3x10-2lb/GWh for existing electrical generating units (EGUs), which represents a challenge for the power-generation industry since 40% of today's units do not have adequate mercury pollution control equipment.
The most reliable and widely utilized solution for mercury capture from power plants is exhaustive activated carbon injection (ACI), for which sorbent recurring costs are at least $5,000 per pound of Hg removed. The development of a new, cost-effective Hg-capture technology is crucial to mitigate human health risks and associated national healthcare costs, and to control industry/consumer costs under the upcoming regulations.
Preliminary work by Pollution Control Technologies, LLC produced a material that could replace the currently used injectable activated-carbon sorbents. The new material is more effective and efficient and potentially less expensive. Current mercury capture technologies have limitations that are largely due to physical sorption and do not address core problems of permanent mercury capture. This technology overcomes these limitations with materials that chemically bind mercury and offer the flexibility of safe disposal.
The researchers are developing, prototyping, and commercializing a proprietary gaseous pollutant capture technology that can be retrofitted to existing coal-fired facilities and incorporated into new ones. The on-demand Hg-capture technology is based on state-of-the-art material-i.e., a reprocessed fly ash byproduct that is reformed into a high-grade Hg oxidizing material via an innovative surface treatment.
Pollution Control Technologies, LLC (PCTech) is:
- Demonstrating the feasibility of fly ash activated with pyridinium tribromides for mercury chemisorption.
- Establishing the Hg capture efficiency of the developed PTB activated fly ash on a pilot-scale combustion unit.
- Validating Hg disposal through HgBr2 extraction from saturated activated fly ash.
The research team is obtaining a complete experimental dataset related to production and implementation of fly ash-based material to permit an accurate cost assessment and to validate the new Hg capture technology. This will set the stage for the development of commercial-grade Hg capture technology and full-scale installations.