(413b) Utilization of Fly Ash Containing Hg from Activated Carbon Injection

In March of 2005 the EPA published final regulations to control mercury emissions from coal-fired electric utilities, and national enforcement is expected to begin in 2010. For the majority of the coal-fired power plants without scrubbers, the most mature retrofit technology available today is the injection of sorbent such as powdered activated carbon (PAC) into the flue gas upstream of the particle control devices. This means that by adopting the PAC injection technology, the resulting high carbon containing fly ash byproduct from coal-fired plants would become unsuitable for concrete applications. The coal-fired power plants would not only lose revenue from the sale of fly ash but would also incur additional expense to dispose of the material. Ceramatec has been working on developing a low cost treatment process where the carbon in the high carbon fly ash is deactivated (as reflected in the foam index tests), and the high carbon fly ash becomes suitable for use in concrete applications.