Lower Mercury Emissions Dramatically with the Nalco Mobotec System

Mercury, a well-known toxin, is a naturally occurring element in coal. During coal combustion, mercury is released into the atmosphere and is eventually deposited into water and onto land. Once mercury enters the water, small microorganisms change the substance into methylmercury, a highly toxic form of mercury that can easily enter the food chain. Consumption of fish and shellfish with high levels of methylmercury can harm the human brain, heart, kidneys and other organs. Mercury emissions can be carried large distances downwind and can affect the health of individuals in many areas of the world. Recent state and federal regulations mandate significant reduction of mercury emissions.

Nalco Mobotec’s suite of patented Hg reduction technologies significantly reduces the volume of mercury emissions being released into the atmosphere, resulting in cleaner air and water. These simple, practical solutions not only reduce mercury emissions on coal-fired boilers, they cost substantially less than comparable mercury emissions control technologies such as SCR/scrubber combinations.

The MERCONTROL^® family of solutions—all of which are supplied by Nalco Mobotec—include halogen injection formulations, as well as non-carbon sorbents that do not compromise fly ash quality. MERCONTROL solutions also include FGD (flue gas desulfurization) re-emission control that binds mercury in the waste materials of an FGD unit and wastewater treatment chemistry that reduces the concentration of mercury to the parts per trillion level. Nalco Mobotec also offers on-site activated carbon production technology, providing our customers a lower-cost alternative to purchasing activated carbon on a long-term supply agreement.

Nalco Mobotec’s patented halogen injection system for Hg reduction converts elemental mercury to mercuric halide, which is adsorbable by coal ash and dry flue gas desulphurization solids. The combination of MERCONTROL Halogen and activated carbon is a lower cost alternative to the injection of bromated activated carbon.

Nalco Mobotec Control Technologies for Hg

Our patented Furnace Sorbent Injection (FSI) System enables us to introduce a variety of chemistries into the boiler furnace. The amount of mercury removed is dependent on many factors from the coal to the emissions control equipment in the plant and Nalco Mobotec has achieved mercury removal rates greater than 90 percent in some cases. Combining the Nalco Mobotec Rotating Opposed Fired Air (ROFA^®) System with the FSI System improves mixing and turbulence while preventing laminar flow. This provides even greater contact between sorbent and mercury in the flue gas, reducing the amount of sorbent required for the desired emission reductions. Our Computational Fluids Dynamics model displays the reduced mercury emissions following installation of our FSI technology.

Another process in development is the patented THIEF technology, in which a small slipstream of partially combusted coal is removed from the burner zone and utilized to generate activated carbon in-situ. This process allows a utility to produce their own activated carbon without having to purchase the material in situations where the cost of supply and transportation would be of concern.

Nalco Mobotec experts will work with your technical and management staff to provide the most cost-effective solution for mercury emissions control to meet the requirements of various air quality regulations. For further information on our mercury reduction technology, please refer to the Mercury Sorbents page.