Poster Session

Use of Activated Fluid Coke for Mercury Capture from Flue Gases

Mihaela Bratu, MSc student in Chemical Engineering

Supervisor - Dr. Sieg Wanke

In October 2006, the Canadian Council of Ministers of the Environment endorsed targets for a 60% reduction in mercury emissions from Canadian coal-fired power plants by 2010 and an 80% reduction by 2018. Many technologies have been proposed and tested for reducing mercury emissions from flue gases; one of these is the use of specially treated activated carbons, e.g. bromine containing activated carbons. One of the problems with some of these special activated carbons is their cost. A potential lower-cost alternative to activated carbon is activated petroleum coke. Physical activation methods used to activate Syncrude fluid coke will be described and the results of characterization of the activated cokes by low temperature nitrogen adsorption, scanning electron microscopy, energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy will be presented. Activation resulted in activated cokes with surface areas in excess of 500 m2/g and sulphur contents which varied with position in the particles. The majority of the sulphur in was present as organic sulphur. Activated fluid cokes with surface areas above 200 m2/g adsorbed mercury at temperatures up to about 140°C. The addition of sulphur to activated fluid coke resulted in strong mercury adsorption at temperatures up to 200°C. A pulse adsorption method, using a cold vapour atomic fluorescence spectrometer for mercury detection, was used to determine the mercury capture ability of the activated fluid coke samples.