ABSTRACT: Geochemistry of Mercury and other trace elements captured by activated carbon during a full-scale combustion test by a Coal-fired power plant in Western Canada

Thecoal-firedpowerplantsinCanadaarerequiredtoreducetheemissionofHgby�60%� before 2010 and 80% for 2018 and beyond to meet the national and regional regulatory targets.�ActivatedcarbonisconsideredbyindustryasanefficientsorbenttocaptureHg� fromthefluegasduringthecombustionprocess.�Awidespreaduseofactivatedcarbon� isanticipatedbythecoal-firedpowerplantstoreducetheemissionofHgandmeettheir� regulatoryobligations.�WhilethesignificantamountofHgisbeingcapturedbythis� methods, very little known about the fate of Hg after capture and possible environmental impactsrelatedtohandlinganduseofHg-richflyash.� This study provides the preliminary results of a comprehensive study on the geochemistry of ElectrostaticPrecipitator�(ESP)�flyashandrelatedfeedcoalsamplesduringanexperiment� trialbyafull-scalecoal-firedpowerplantinWesternCanada.�Theobjectiveistostudythe� efficiencyofcaptureofHgandothertraceelementsby�5�differentcommercialactivated� carbons and effects of various parameters such as geochemistry of coal and combustion variables during various activated carbon injection episodes. The results indicate the capture efficencyofHgiscontrolledbyamountofflyashcarbon,�particlesize,�andinjectionrate� of activated carbon. Furthermore, the study examines the speciation of Hg and other trace elements,�aswellas,�theleachabilityoftheseelementsfromthecapturedflyashduringthe� activated carbon tests.