Activated Carbon for Mercury Removal: Selecting the Right Grade for Flue Gas and Process Streams

Mercury in combustion flue gas and many process streams is captured by activated carbon through physical adsorption on the porous surface, especially in micropores, and by chemical reaction when the carbon is impregnated with sulfur, iodine or other reagents. Elemental mercury (Hg0) is the hardest form to capture because it is insoluble and volatile, so grades intended for mercury duty are selected for high micropore volume, a suitable impregnation and a pore structure that promotes contact at the operating temperature.

For mercury duty, three groups of properties are normally compared before a grade is confirmed:

• Surface area and micropore volume set the number of adsorption sites and the working capacity.

• Adsorption indicators such as methylene blue and CTC adsorption help compare pore development and gas-phase activity between grades.

• Mechanical and handling data such as hardness, moisture, ash, bulk density, pH and particle size confirm the carbon can survive the intended contactor.

The statement of work, the solids loading and the available pressure drop decide the form. Granular or pelletized carbon (typically 4x8, 4x10 or 6x12 mesh) suits fixed beds and flue-gas injection or bed systems where dusting must be limited. Powdered carbon suits injection into a duct or baghouse or a short-contact process. This series can be supplied from 4 to 40 mesh, so the right cut depends on your contactor design rather than on the mercury level alone.

Start from the duty, not from a single number. Share the gas or liquid composition, mercury concentration and speciation, flow rate, operating temperature and pressure, contact time, water or acid content, target outlet level and the contactor form you intend to use. From those inputs we can discuss a grade and an agreed specification plan. Batch values are confirmed before quotation, and mercury performance on a specific stream is not guaranteed because it depends on the full operating envelope.

Please send the treatment target (mercury in flue gas, incinerator off-gas, natural gas or a liquid stream), the inlet concentration and flow rate, the required outlet specification, the expected contactor form and particle size, and the quantity for the first order. If a specific document set is required, state which reports or certificates you need. We will check the application and the quoted specification with the responsible technical contact, and confirm price, availability and delivery in writing rather than on this page.

Our company holds an ISO 9001:2015 certificate (No. 06524Q01338R0S, valid until 11 June 2027) whose scope is activated carbon sales. RoHS sample reports and an SDS are also available. These documents refer to the samples and the scope actually stated in them, and they are not a certification of every product in the series. The document set released with a particular order is confirmed during the enquiry, together with the agreed specification plan.