![[logo] US EPA](https://webarchive.library.unt.edu/eot2008/20081108124445im_/http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Final Report: High Capacity Sorbent for Removal of Mercury from Flue Gas
EPA Contract Number: 68D01058Title: High Capacity Sorbent for Removal of Mercury from Flue Gas
Investigators: Turchi, Craig S.
Small Business: ADA Technologies Inc.
EPA Contact: Manager, SBIR Program
Phase: II
Project Period: September 1, 2001 through September 1, 2003
Project Amount: $224,976
RFA: Small Business Innovation Research (SBIR) - Phase II (2000)
Research Category: SBIR - Air , Air Quality and Air Toxics
Description:
For the past 3 years, ADA Technologies, Inc. (ADA), has been developing and testing a new class of mercury control sorbents called Amended Silicates™, with the overall goal of commercializing these sorbent materials for removal of vapor-phase mercury from coal-fired flue gas streams. Amended Silicates offer cost and performance advantages in mercury removal applications, especially as a direct substitute or "drop-in" replacement for activated carbon. The U.S. Environmental Protection Agency's (EPA) decision to regulate mercury emissions from coal-fired utility boilers has created a substantial market opportunity for this technology, and is a primary driver in the creation of a joint venture company with CH2M Hill to manufacture and market Amended Silicate sorbents.
Sorbent development and testing activities supported by EPA were divided between laboratory work to develop the Amended Silicate sorbent formulations and field trial tests to demonstrate the performance of injected sorbents in actual coal-fired flue gas streams. Through the sorbent development work, ADA identified a natural mineral silicate substrate proven to be superior for preparing Amended Silicates. This substrate is low-cost, mined, and sold in quantities of hundreds of thousands of tons annually.
The active component of the Amended Silicate sorbents is a proprietary chemical that is not a coating, but rather a chemical amendment integrated into the structure of the substrate material. Over the course of the project, ADA has experimented with numerous amendment chemicals and processes and has produced a sorbent material proven to have exceptional mercury capacity both in laboratory and field tests. Estimates of the manufactured cost for this new class of mercury sorbents, when made in a dedicated production facility, are comparable with activated carbon.
Summary/Accomplishments (Outputs/Outcomes):The sorbent manufacturing process was scaled up from bench-top quantities (20 g) to laboratory-scale quantities (12 kg) to produce enough sorbent material for field trial tests. Two large sorbent batches were made to support sorbent injection tests at Hazen Research (Golden, CO) and at Xcel Energy's Comanche Power Station (Pueblo, CO). Both sorbent batches made for injection tests were prepared with the same chemical amendment, but were applied to substrate materials from different sources.
The effectiveness of the Amended Silicate sorbents for mercury control in actual coal-fired flue gas first was demonstrated at Hazen Research using a pilot-scale coal combustor. Tests showed mercury was removed from combustion gas in two modes. The first mode, termed in-flight mercury removal, is the adsorption of gas-phase mercury onto sorbent particles in contact with the gas stream in ductwork leading to the particulate control equipment. The second mode is a measure of mercury removal as the flue gas is passed through the filter cake accumulated on the particulate filter media. Injection rates for the Hazen tests varied between 2.5 and 6 pounds per million actual cubic feet of flue gas (lb/MMacf). Data indicated that a 71 percent mercury capture was attained at an injection rate of 5.9 lb/MMacf, with 49 percent of the mercury captured by the in-flight mode and 22 percent of the mercury captured as the flue gas passed through the filter cake on the particulate filter element.
The second series of field tests were conducted in cooperation with Xcel Energy at the Comanche Power Station, where ADA previously operated a pilot plant to evaluate mercury control sorbents. The pilot plant treats 600 acfm of actual flue gas extracted from the host facility for testing purposes. A total of six sorbent injection tests were carried out with Amended Silicate sorbent for this project. Results showed that the sorbents performed well, with an average mercury removal greater than 80 percent when sorbent injection rates were 4 lb/MMacf over a 2-hour sorbent injection time. An extended sorbent injection test also was conducted to demonstrate increased mercury removal as a result of the buildup of sorbent in the filter cake on the filter media. In this test, sorbent was injected into the flue gas stream at a very low rate of 0.8 lb/MMacf. Within 4.5 hours of the start of sorbent injection, the mercury concentration at the outlet of the baghouse was reduced by 89 percent.
Conclusions:The dramatic success of this Phase II research project significantly has advanced the commercialization of the ADA Amended Silicate sorbent technology. This Phase II research project drew on the success of each task to build support for, and confidence in, the sorbent performance, leading to the creation of a joint-venture company with CH2M Hill, ADA’s Phase III commercialization partner. This joint venture (Amended Silicates, LLC) became a reality in July 2003, and is tasked with commercial production and marketing of the ADA Amended Silicate sorbents. CH2M Hill has an existing client base of utilities, all of which will be required to meet EPA mercury control regulations to be issued in draft form in 2003, and finalized in 2004. Success of the ADA Amended Silicate sorbent will allow Amended Silicates, LLC to offer a low-cost mercury control option to current and new utility clients of CH2M Hill, as well as to other utilities seeking cost-effective mercury control options. The new company has a business plan and commitments for resources from parent companies that will make available in the marketplace a supply of Amended Silicate in 2006, in time to meet pending government regulations.
Journal Articles:No journal articles submitted with this report: View all 2 publications for this project
Supplemental Keywords:high capacity sorbent, mercury removal, flue gas, Amended SilicateTM, coal-fired flue gas streams, activated carbon, mercury emissions, utility boilers, air pollution, mercury control, sorbent injection, small business, SBIR. , Toxics, Air, Scientific Discipline, Waste, RFA, Engineering, Chemistry, & Physics, Chemical Engineering, HAPS, Incineration/Combustion, air toxics, Chemistry, Environmental Engineering, Environmental Chemistry, National Recommended Water Quality, 33/50, coal combustion, flue gases, flue gas, regeneration sorbent, removal, mercury & mercury compounds, coal, flue gas emissions, mercury, sorbents, Mercury Compounds
Progress and Final Reports:
2000 Progress Report
Original Abstract
High-Capacity, Regenerable Sorbent for Removal of Mercury From Flue Gas