Grantee Research Project Results

Final Report: A Low-Cost, High-Temperature Mercury Sorbent for Coal-Fired Power Plants

EPA Contract Number: 68D00263
Title: A Low-Cost, High-Temperature Mercury Sorbent for Coal-Fired Power Plants
Investigators: Nelson, Sid
Small Business: Sorbent Technologies Corporation
EPA Contact:
Phase: I
Project Period: September 1, 2000 through March 1, 2001
Project Amount: $69,990
RFA: Small Business Innovation Research (SBIR) - Phase I (2000) RFA Text |  Recipients Lists
Research Category: SBIR - Air Pollution , Small Business Innovation Research (SBIR) , Air Quality and Air Toxics

Description:

After many years of study, the U.S. EPA recently announced in a Regulatory Finding that it had determined that: "The conclusions, as a whole, support a finding that regulation of coal-fired electric utility steam generating units for hazardous air pollutants, particularly mercury, is appropriate and necessary." Thus, a regulatory rulemaking process has begun that will see final mercury regulations for all U.S. coal-fired power plants promulgated by the end of 2004.

The purpose of this research project was to evaluate various options available in the production of a novel duct-injection sorbent material for the removal of mercury from utility flue gases. In the project, a number of different sorbent production variables were explored. The new sorbents were successfully produced from the raw materials of numerous commercial suppliers. In the laboratory, tests were performed examining the elemental mercury removal capabilities of variations of the sorbents on simulated coal-fired flue gas streams. Sorbent stability was also examined in the project, including possible off-gassing of toxic species and leachability.

Summary/Accomplishments (Outputs/Outcomes):

The new sorbents were simple to prepare in bulk. They were found to remove elemental mercury from simulated flue gas through a novel chemisorption process. The sorbents themselves were found to be very stable. Experimental results indicate that extremely high mercury capacities for the materials are possible. Finally, one version of the materials was produced that may relieve bulk-gas mass transfer limitations inherent in the duct-injection application of other sorbents, such as powdered activated carbon (PAC), a possible competitive technology. This would enable the new sorbents to achieve 90+% removal rates at low?cost injection ratios. Unlike PACs, the new sorbents examined in this project appear to be capable of high mercury removal without requiring added flue-gas cooling systems or extended time on a fabric filter.

Conclusions:

It was concluded that use of the new materials is not only technically feasible, but that they may also significantly reduce utility mercury-removal costs compared to existing technologies. It was recommended that development of this important new technology be accelerated in a Phase II project which would include pilot-scale duct-inject testing at an actual coal-fired site.

Supplemental Keywords:

mercury, sorbent, coal, duct injection, retrofit, flue gas, utilities., RFA, Air, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Waste, Toxics, Chemical Engineering, HAPS, Environmental Chemistry, Engineering, Chemistry, & Physics, Incineration/Combustion, Futures, Monitoring/Modeling, air toxics, Environmental Engineering, elemental mercury, removal, flue gases, coal fired power plants, sorbents, flue gas, Mercury Compounds, coal combustion, coal combustion wastes

SBIR Phase II:

A Low-Cost, High-Temperature Mercury Sorbent for Coal-Fired Power Plants  | 2000 Progress Report  | Final Report