mercury capture by fly ash carbon sorbent in a fixed bed
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
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
)()()(
)(
zkyjxi
cuRcDtc
ts
• The Convection Diffusion Equations
0
)])(([)(
u
FuuIuutu T
• Incompressible Navier-Stokes Equation
Formulation
Results and Observations
Observations-2
Observations-3
Observations-4.1
Observations-4.2
Validation
00.10.20.30.40.50.60.70.80.9
1
0 2 4 6 8 10 12 14 16 18 20Hrs
Inlet abs
0
0.1
0.2
0.3Outlet abs
Sorbent bed inlet
Sorbent bed outlet
COMSOL breakthrough curve at center of sample tube outlet
COMSOL breakthrough curve along the side of the sample tube outlet
Actual experimental results
Parametric StudyCOMSOL breakthrough curve
with actual reaction rate
COMSOL breakthrough curve with reaction rate increased by 10000 times
-0.10
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000Secs
AAS response
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, 2005. Available at http://www.epa.gov/air/mercuryrule/.
American Coal Ash Association, 2003 COAL COMBUSTION PRODUCT PRODUCTION AND USE SURVEY (online), Available at http://www.acaa-usa.org/PDF/2003_CCP_Survey(10-1-04).pdf.
Iliuta I, Petre CF, Larachi F, CHEMICAL ENGINEERING SCIENCE 59 (4): 879-888 2004
Wu YX, Wang X, Ching CB, J. CHEMICAL ENGINEERING & TECHNOLOGY 27 (9): 955-961 2004
Etc…(the rest of reference list is in the final paper)
Questions?