Dynamic mercury control
Recent environmental legislation requires US cement plants to tighten up their mercury control procedures. ADA Carbon Solutions has developed the Dynamic Mercury Index test to help ensure consistent quality of sorbents used in activated carbon injection and, as a result, maintain an effective mercury control process. By Chris Vizcaino and Sheila Glesmann, ADA Carbon Solutions LLC, USA.
T o help meet the US Maximum Achievable Control Technology (MACT) mercury (Hg) limit of 55lb Hg/Mt clinker on a 30-day rolling average, cement plants carry out dry injection of powdered activated carbon (PAC) into the flue gas stream in a process known as activated carbon injection (ACI). Each application for PAC has some unique characteristics and sorbents may require ‘fine-tuning’ for optimal performance in a given configuration. Once a PAC is found to be effective full-scale, assurance of continued high quality control and consistency is key to compliance reliability.