Mercury is one of the most strictly controlled trace contaminants in industrial gas and liquid streams. Even at very low concentrations, it forms amalgams with aluminium that cause catastrophic damage to cryogenic heat exchangers, contaminates downstream adsorbents, and creates emission control challenges in combustion flue gas. Activated carbon, particularly in sulphur impregnated grades, is the dominant technology used to capture mercury reliably across all of these applications. As an activated carbon manufacturer, SorbiTech provides specialist mercury capture grades engineered for natural gas processing, refinery service, and flue gas treatment.
How Sulphur Impregnated Carbon Captures Mercury
Mercury exists in industrial gas streams in three main forms: elemental mercury vapour, oxidised mercury species such as mercuric chloride, and particulate bound mercury. Each form responds differently to capture technology, and the most reliable approach across all three is the use of sulphur impregnated activated carbon.
The base carbon is impregnated with elemental sulphur dispersed throughout the internal pore structure. When mercury contacts the impregnated carbon, it reacts chemically with the sulphur to form mercuric sulphide, a stable and insoluble compound that remains locked inside the pores of the carbon. The reaction is essentially irreversible under normal operating conditions, which means the captured mercury cannot desorb if process conditions change later in the operating cycle.
Mercury Removal in Natural Gas and LNG Plants
Natural gas from many production regions contains trace mercury at concentrations from a few micrograms to several thousand micrograms per normal cubic metre. Removing this mercury before the gas reaches a cryogenic LNG plant is essential, because mercury reacts with aluminium heat exchanger tubes and causes catastrophic equipment failure. Sulphur impregnated activated carbon beds, sized for ten years of operation between change outs, are the industry standard for natural gas mercury removal. The technology is closely related to the gas conditioning beds used for biogas and natural gas purification duties.
Mercury Capture in Refinery and Petrochemical Streams
Crude oil and natural gas condensate from many production regions carry mercury at trace levels. In refineries, mercury must be removed early in the process train to protect downstream catalysts, heat exchangers, and product specifications. Both vapour phase and liquid phase mercury removal beds are commercially available, with the carbon grade and bed configuration selected based on the specific hydrocarbon stream and operating conditions.
Mercury Control in Combustion Flue Gas
Coal fired power plants, cement kilns, and waste incinerators emit mercury that must be controlled to meet emission limits. The standard approach is powdered activated carbon injection upstream of the particulate control device, where the carbon adsorbs mercury and is then collected with the fly ash. Halogen treated grades such as bromine impregnated carbon offer enhanced performance for low chlorine fuels and elemental mercury dominated streams. The same approach is used in cement kilns and waste incinerators, where activated carbon also captures dioxins and furans alongside mercury in the same compliance step.
Mercury Removal from Industrial Wastewater
Some industrial wastewater streams, including those from chlor alkali plants and historical gold mining sites, contain dissolved or particulate mercury. Sulphur impregnated activated carbon removes mercury from these aqueous streams to below regulatory limits, often achieving non detection levels at the discharge point. The treatment principle is the same as for gas phase mercury, but the bed is operated as a liquid phase contactor with appropriate empty bed contact time and backwash provisions.
Selecting Activated Carbon for Mercury Service
Sulphur loading is the primary parameter for mercury capture grades, with typical commercial products carrying ten to fifteen percent sulphur by weight. The base carbon is usually coal based for gas phase service because of its balanced pore structure, while powdered grades for flue gas injection use both coal and lignite based carbons. Particle size, hardness, and operating temperature limits all influence grade selection, and operators specify these parameters in the procurement documentation along with the certificate of analysis required at delivery.
Why SorbiTech™ for Mercury Removal Solutions
An established provider of activated carbon solutions for mercury removal, SorbiTech™ supports industrial applications where trace mercury presents significant operational and environmental risk. Mercury capture solutions are developed through application driven engineering and continuous research, enabling reliable and stable performance across natural gas processing, refining, and combustion‑based industries.
Mercury control strategies are defined in alignment with process conditions, regulatory requirements, and long term performance stability, ensuring consistent operation throughout the lifecycle of the system.
Technical support and application evaluation are available for mercury capture system design and operational requirements.