Tri-Mer’s UltraCat ceramic filter system is compatible with standard mercury removal techniques. Control of mercury is notoriously difficult: each instance is analyzed individually and customized solutions are engineered. A few general observations can be offered, however.
The catalytic filters can handle very high particulate loads while maintaining exceptionally low outlet levels.
Just as the addition of dry sorbents for the removal of acid gases is effective, so is the addition of powdered activated carbon (PAC) for mercury.
In general, regular PAC becomes less effective with temperature, topping out around 400°F. The chemical composition of the pollutant gas plays a major role; hence, the difficulty of blanket statements.
At higher temperatures, brominated PAC is required. According to the manufacturers of brominated products, temperatures of 500°F to 800°F are acceptable.
Significant levels of mercury removal have also been achieved with injected powdered trona.
Many new sorbents for mercury removal have been introduced in recent years; some of these appear very promising.
The nano-catalyst used for NOx removal also breaks down dioxins. Optimum dioxin control is limited to an upper temperature of 500°F if there are constituents such as chlorine, fluorine, and other halides that can lead to re-formation of the dioxin. If these have largely been removed upstream in the injection of dry sorbent, permanent dioxin destruction will occur at higher temperatures as well. Within a wide range, destruction efficiency is typically 97% to 99%.