Mercury Capture by Fly Ash Carbon Sorbent in a Fixed Bed 2-D Finite Element Computational Modeling Brandie Markley & Onur Mustafaoglu

Project Motivation  EPA’s Clean Air Mercury Rule  Passed March 15, 2005  Targets coal-fired power plants  Mercury  Toxic  Persistent  Bioaccumulation  Activated Carbon Injection Using Fly Ash  Promising technology  63% of fly ash produced is disposed in landfills  Inherent properties of fly ash

Statement of the Problem

Governing Equations The Convection Diffusion Equations Incompressible Navier-Stokes Equation

Formulation

Results and Observations

Observations-2

Observations-3

Observations-4.1

Observations-4.2

Validation COMSOL breakthrough curve at center of sample tube outlet COMSOL breakthrough curve along the side of the sample tube outlet Actual experimental results

Parametric Study COMSOL breakthrough curve with actual reaction rate COMSOL breakthrough curve with reaction rate increased by times Experimental data

Conclusion  Velocity develops and mercury breakthrough occurs most quickly at the center of the element  Adsorption through the element behaves as expected  COMSOL is an effective modeling tool for this application  COMSOL data matches experimentally observed results  Further investigation is needed for accurate parameter identification (e.g., force velocity, dynamic viscosity, diffusion coefficient)

Works Cited  U.S. EPA. CLEAN AIR MERCURY RULE (online), March 15, Available at  American Coal Ash Association, 2003 COAL COMBUSTION PRODUCT PRODUCTION AND USE SURVEY (online), Available at  Iliuta I, Petre CF, Larachi F, CHEMICAL ENGINEERING SCIENCE 59 (4):  Wu YX, Wang X, Ching CB, J. CHEMICAL ENGINEERING & TECHNOLOGY 27 (9):  Etc…(the rest of reference list is in the final paper)

Questions?