Mercury exposure poses a well-documented threat to human health as a neurotoxin. Since mercury is a naturally occurring element in the earth’s crust, certain processes such as mining and combustion of fossil fuel cause mercury to spread and contaminant air, water, and soil.
According to the EPA, in 1990, the three largest producers of U.S. mercury emissions were medical waste incinerators, municipal waste combustors, and power plants. By 2005, medical waste incinerators and municipal waste combustors had reduced mercury emissions by more than 95%.
APC is highly qualified in the removal of mercury from gas streams that occur in a wide range of production processes and air emission control applications. Sources of airborne mercury emissions that we have experience mitigating include:
- Wastewater treatment plants—sewage sludge incinerators
- Gold production
- Silver, antimony and other metal production
- Municipal, medical, and hazardous waste incinerators
- LNG production
- Utility boilers and other small coal-fired boilers
- Waste-to-energy plants
- Other industrial exhaust streams
Our experience includes the challenging task of removing mercury from natural gas in LNG production, where very high gas pressures are encountered (700-2,000 psi), and extremely low residual mercury concentrations– 0.01 µg/Nm3 or lower– are required. With necessary removal rates as high as 99.99%, slow diffusional kinetics due to high gas pressures, and competition from C3 and heavier hydrocarbons in the natural gas, these applications are the most difficult mercury removal applications documented.
For mitigating airborne mercury emissions, options include activated carbon adsorption beds and powdered activated carbon injection systems.
APC’s MercPure Fixed Bed (FB Series) systems offers the highest removal efficiencies for mercury emissions using fixed adsorption beds of specialty activated carbon. APC is media-independent and will select the best media available on the market for the application considering cost, performance, and bed longevity. APC offers full gas pre-conditioning systems including mist removal, gas heating to reduce relative humidity (gas conditioning), and multiple options to protect the carbon bed from particulate fouling, such as APC’s unique Ultra High-Efficiency Filter (UHF®) unit, which can precede the adsorption vessel to remove ultra-fine condensed (liquid-phase) and solid particulate, greatly extending the carbon bed life and also allowing continuous mercury removal at high efficiency. Further to these features, APC designs its systems properly to eliminate exothermic events, unlike some other vendors in the industry, allowing continuous operation without safety risks. Mercury emission removal efficiencies by APC MercPure FB systems are commonly in the range of 99.9% or higher as measured through Owner compliance tests.
APC’s MercPure powdered activated carbon (PAC Series) injection systems include carbon metering and injection systems, interconnecting ductwork and piping, and downstream fabric filter to deliver mid to high removal efficiencies (up to approx. 90%).
Are you in need of a mercury emission mitigation plan for your process? Contact the APC Technologies team today.