Low-Cost Mercury Sorbents Derived From Waste Tires

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. 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).