Improved Sorbent for Removing Mercury from Hazardous Waste Incinerators

TDA Research, Inc., (TDA) is developing a novel non-carbon sorbent to control mercury emissions from flue gas from hazardous waste incinerators and coal-fired power plants. The sorbent could be easily injected into the flue gas and could be recovered in the Particulate Control Device (PCD) along with the fly ash, minimizing capital investment. Unlike the carbon materials used to date, our sorbent does not alter the properties of the by-product fly ash and render it unsuitable as a cement additive. Our materials combine an oxidation catalyst/oxidizing agent in the same particle. The catalyst oxidizes the difficult-to-remove elemental mercury to the much easier to stabilize Hg+2. The oxidized mercury then tightly binds to the sorbent. As a result of this dual function, our sorbents have high capacity, good activity, and can work at much higher temperatures because the mercury is tightly bound to the surface. In the Phase I project, we demonstrated the technical feasibility of using the non-carbon sorbent for mercury removal. The sorbent achieved a higher mercury capacity than the Norti-FGD carbon, the benchmark sorbent in mercury emission control form flue gases, at 150°C (over 2,000 µg/g) in a fixed -bed experimental setup under representative simulated flue gas. Unlike the carbon sorbent, which do not work at higher temperature, our formulation also performed well at high temperature, absorbing 250 µg/g at 245°C. The high temperature operation capability of the sorbent allows its use on the hot-side of an electrostatic precipitator (ESP).In Phase II, we will continue to optimize the sorbent formulation and scale-up its production. In collaboration with Apogee Scientific, Inc. (Apogee) we will demonstrate its performance in a pilot-scale flow apparatus using actual flue gas generated by burning {powder Rive Basin (PRB) coal. Our Commercial partners will assist us in our scale-up, evaluation and commercialization efforts to improve our chances of successful sorbent development. Commercial Applications This technology may find immediate use for mercury abatement in hazardous waste incinerators. In addition, the same technology would be applicable to the much smaller application of mercury abatement in municipal waste incinerators and waste-to-energy facilities. These facilities are becoming more prevalent in the U.S., and are particularly common in Europe, where trouble-prone packed beds of carbon are currently used. When regulated coal-fired power plants represents an even larger market, accounting for 60% of the electric power generated in the U.S.