An Improved Sorbent for Mercury AbatementEPA Contract Number: 68D00281
Title: An Improved Sorbent for Mercury Abatement
Investigators: Bell, William L.
Small Business: TDA Research Inc.
EPA Contact: Richards, April
Project Period: September 1, 2000 through September 1, 2002
Project Amount: $225,000
RFA: Small Business Innovation Research (SBIR) - Phase II (2000) Recipients Lists
Research Category: Air Quality and Air Toxics , SBIR - Air Pollution , Small Business Innovation Research (SBIR)
Description:Coal-fired electric utilities produce the majority of the electric power generated in the United States. They also represent the largest single source of anthropogenic-mercury emissions. Regulation of these emissions currently is under consideration. Dry sorbent injection is an attractive approach to mercury abatement that could easily be retrofitted into existing electric utilities. The sorbent is injected into the flue gas and removed with the fly ash in the particulate control module. Because the sorbent is used only once and then disposed of, a low-cost sorbent is essential. Unfortunately, the sorbent materials now under consideration (such as activated carbon) are too expensive.
In Phase I, TDA Research, Inc. (TDA) demonstrated the feasibility of a new process to modify noncarbon feedstocks to improve their ability to capture mercury from coal combustion flue gas. TDA prepared samples using a variety of additives and combinations of additives on several different noncarbon feedstocks and then tested these sorbents using a packed-bed mercury breakthrough apparatus. TDA further demonstrated a very simple and inexpensive sorbent production method. The method proved to scale readily from 10-g samples to 5-lb batches, indicating that no loss of performance is likely as larger quantities are prepared. An engineering cost analysis indicated that the new sorbents could be produced for $160 to $230 per ton, compared with $500 to $1,000 per ton for activated carbon.
In Phase II, TDA plans to optimize formulation of the sorbent to further lower cost and then test performance in the sorbent injection mode. The sorbent injection tests will employ the same apparatus used in previous similar tests, so the data obtained can be compared to other well-defined sorbent systems. TDA then will scale-up the production method to 50-lb batches, which will verify the performance of the production method and provide material for evaluation by potential users. TDA's marketing efforts will be assisted by a strategic alliance with a company now active in pollution abatement in coal-fired utilities.