Low-Cost Mercury Sorbents Derived From Waste TiresEPA Contract Number: 68D03039
Title: Low-Cost Mercury Sorbents Derived From Waste Tires
Investigators: Wojtowicz, Marek
Small Business: Advanced Fuel Research Inc.
EPA Contact: Richards, April
Project Period: May 1, 2003 through April 30, 2005
Project Amount: $224,678
RFA: Small Business Innovation Research (SBIR) - Phase II (2002) Recipients Lists
Research Category: SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)
In this research project, Advanced Fuel Research, Inc., addresses two important environmental problems: (1) removal and recovery of mercury from combustion/incineration flue gas, and (2) reprocessing of waste tires into value-added products. Coal combustion and incineration of municipal and hazardous wastes results in air pollution due to emissions of trace amounts of heavy metals. Because of the high toxicity of these species, their emissions are or will be regulated. The high volatility of mercury makes control of this metal particularly difficult. Scrap tires present formidable disposal problems, as they are known to be immune to biological degradation.
Landfilling of the 280 million tires that are generated each year in the United States is an unacceptable solution. In addition to the continuous flow of waste tires, there are approximately 2-3 billion tires already stored in piles throughout the country (http://home.snafu.de/kurtr/str/en.html Exit ). Legal dumping also is a problem. The tires take up large amounts of valuable landfill space, provide breeding sites for mosquitoes and rodents, and present fire and health hazards.
The proposed approach is based on mercury adsorption on low-cost, sulfur-rich activated carbons derived from scrap tires. The sulfur added to tire rubber in the process of vulcanization makes the tire-derived sorbents particularly effective in mercury removal due to the high chemical affinity between mercury and sulfur. Two possible implementations of the process are envisaged: (1) sorbent injection into the flue-gas duct (near-term applications), and (2) a patented regenerative scheme (long-term applications). The overall objective of the project is to develop a novel and effective technology for mercury control using sorbents derived from waste tires. The objective of the Phase I project was to demonstrate the superior price-performance characteristics for waste tire-derived activated carbons under simulated industrial conditions, which was successfully accomplished. The Phase II objective is to optimize sorbent properties as a function of carbon-preparation conditions, and to advance the product to pilot scale (Phase II Option). This will be accomplished through the following tasks: (1) sorbent optimization, (2) sorbent performance, (3) product evaluation, and (4) pilot-scale testing (Phase II Option).
The main result of this research will be a novel technology for the removal of mercury from combustion/incineration flue gas combined with the simultaneous utilization of massive amounts of solid waste (scrap tires). The obvious applications for the process are coal-fired power plants, as well as municipal, medical, and hazardous waste incinerators.