Activated Activated Carbon Model Carbon Model SimulationsSimulations

Matthew Arnold Kevin BongiovanniMatthew Arnold Kevin Bongiovanni

Garret Jackson Jessica GabouryGarret Jackson Jessica Gaboury

Brandon McdonaldBrandon Mcdonald

Granular Activated CarbonGranular Activated Carbon

The raw material used for Granular The raw material used for Granular Activated Carbon (GAC) has a high Activated Carbon (GAC) has a high carbon content.carbon content.

The carbon based material is The carbon based material is converted to activated carbon by converted to activated carbon by thermal decomposition in a furnace thermal decomposition in a furnace using a controlled atmosphere and using a controlled atmosphere and heat.heat.

Activated CarbonActivated Carbon

The pores in The pores in activated carbon activated carbon result in a large result in a large surface area.surface area.

A gram of A gram of activated carbon activated carbon can have a surface can have a surface area of 500 to area of 500 to 1500 meters 1500 meters squared.squared.

BiofiltrationBiofiltration Biofiltration uses microorganisms to control Biofiltration uses microorganisms to control

air pollution.air pollution. Dynamically varying load condition may have Dynamically varying load condition may have

adverse effects on biofilters. adverse effects on biofilters. Large amounts of Large amounts of

pollutants may result pollutants may result in unacceptable high in unacceptable high contaminant contaminant emissions.emissions.

Small or no amount Small or no amount of pollutants may of pollutants may cause starvation cause starvation conditions. conditions.

The GAC FilterThe GAC Filter

A GAC filter passively controls and A GAC filter passively controls and regulates the flow of pollutants.regulates the flow of pollutants.

The submicroscopic pores in The submicroscopic pores in activated carbon trap pollutants activated carbon trap pollutants through a process called adsorption.through a process called adsorption.

As clean air or water flows through As clean air or water flows through the filter GAC release stored the filter GAC release stored pollutants.pollutants.

Filter DiagramFilter Diagram

The Glass beads The Glass beads and wool evenly and wool evenly disperse air flow.disperse air flow.

A syringe pump A syringe pump empties pollutants empties pollutants into the air supply.into the air supply.

What’s the ValueWhat’s the Value

The GAC filter could be used as a The GAC filter could be used as a load equalization mechanism, load equalization mechanism, keeping a steady flow of pollutants keeping a steady flow of pollutants moving into the biofilter.moving into the biofilter.

The effects of the GAC filter must be The effects of the GAC filter must be modeled and calculated to minimize modeled and calculated to minimize use of biofilter.use of biofilter.

This allows for smaller and cheaper This allows for smaller and cheaper biofilters to be used.biofilters to be used.

Liquid Phase DiagramLiquid Phase Diagram

Reaching EquationReaching Equation

(mass of adsorbate entering by (mass of adsorbate entering by advection)-(mass of adsorbate advection)-(mass of adsorbate leaving by advection)=(mass leaving by advection)=(mass accumulated of adsorbate I in the accumulated of adsorbate I in the liquid phase)+(mass accumulated in liquid phase)+(mass accumulated in the adsorbent phase)the adsorbent phase)

In equation form:In equation form:

, ,

[ ( , ) ( , )] [ ( , ) ( , )]

[ ( , ) ( , , )]i i i i

p f i i p i

A C z t C z dz t t A C z t dt C z t z

A K C z t C r R z t t

Equation and ConditionsEquation and Conditions

Make substitutions to reach liquid Make substitutions to reach liquid phase mass balance in dimensionless phase mass balance in dimensionless formform

ICIC (initial concentration is 0)(initial concentration is 0)

BCBC

(incoming concentration is a specified constant)(incoming concentration is a specified constant)

][3)1(

1,ipiti

gi CCSC

TDCz i

t

0]1

1,1)1([

tt

t

ggi D

TzDTC

1)0,0( TzCi

Intraparticle Phase diagramIntraparticle Phase diagram

Reaching EquationReaching Equation

(Mass of adsorbate i entering at r)-(Mass of adsorbate i entering at r)-(Mass of adsorbate i leaving at (Mass of adsorbate i leaving at r+dr)=(Mass of Adsorbate I r+dr)=(Mass of Adsorbate I accumulated in spherical shell)accumulated in spherical shell)

Derivation of intraparticle phase Derivation of intraparticle phase mass balancemass balance

tippiadttippiadrritotritot drrCqdrrCqdtrJdtrJ ]4)[(]4)[(]4[]4[ 2,

2,

2,

2,

Equation and ConditionsEquation and Conditions

Make substitutions to reach dimensionless form Make substitutions to reach dimensionless form

ICIC (initial concentration is 0)(initial concentration is 0)

1st BC1st BC (concentration is constant at center)(concentration is constant at center)

2nd BC2nd BC (adsorbate accumulaed in particle (through both surface and pore diffusion)=adsorbate transferred (adsorbate accumulaed in particle (through both surface and pore diffusion)=adsorbate transferred

through liquid phase boundary)through liquid phase boundary)

),,()1(

)]],,()(),,(

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,,,,,2

2

TzrYTD

D

TzrCr

EdDEdr

TzrYEdDEdr

rr

ig

g

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ipiis

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1

0

2 TzrCTzCSrdrTzrYtD

Dipiti

g

g

i

t

i

0)0,10,10( TzrYi

To solve systemTo solve system

Final equilibrium condition Final equilibrium condition

in

ii

m

lkkk

m

lkk

iip Kn

tzrqn

tzrq

tzrqtzrC ]

),,([

),,(

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pii

Introduction to Matlab GUIIntroduction to Matlab GUIThis is a blank Matlab This is a blank Matlab

GUI.GUI.

We use this window to We use this window to customize our customize our interface.interface.

If you notice on the left If you notice on the left hand side, you’ll see hand side, you’ll see three colored circles.three colored circles.

Blue = Push buttonsBlue = Push buttons

Red = Edit boxesRed = Edit boxes

Green = Text boxesGreen = Text boxes

We use these to create We use these to create options for our options for our interface window.interface window.

Functional GUI WindowFunctional GUI Window

This window is our fully customized GUI. A GUI is just shorthand for graphical This window is our fully customized GUI. A GUI is just shorthand for graphical user interface. Our GUI consists of three types of elements arranged in a user interface. Our GUI consists of three types of elements arranged in a way to make it easy for the user to know what and where to input.way to make it easy for the user to know what and where to input.

You can see our GUI is broken into three sections, Adsorber Inputs, Adsorbent You can see our GUI is broken into three sections, Adsorber Inputs, Adsorbent Inputs, and Kinetic Properties.Inputs, and Kinetic Properties.

- Adsorber Inputs are the things we know about the flow process. Namely, Adsorber Inputs are the things we know about the flow process. Namely, things like the bed diameter, length, porosity, and the flow rate.things like the bed diameter, length, porosity, and the flow rate.

- Absorbent Inputs are the things we know about the Granulated Carbons. Absorbent Inputs are the things we know about the Granulated Carbons. Radius, density, and porosity are included here.Radius, density, and porosity are included here.

- Kinetic Properties are inputs about the actual pollutants we are filtering. Kinetic Properties are inputs about the actual pollutants we are filtering. Each of these will be unique for various components.Each of these will be unique for various components.

GAC GUI InterfaceGAC GUI Interface

Break Time for Break Time for Mathematics!Mathematics!

One particularly important aspect to keep in mind for this project is the One particularly important aspect to keep in mind for this project is the station numbers. Station numbers will be identified in our output legends.station numbers. Station numbers will be identified in our output legends.

Basically, a station number is just a way for us to recognize what position we Basically, a station number is just a way for us to recognize what position we are at inside of the filter. Think about it as a line graph.are at inside of the filter. Think about it as a line graph.

11 2 2 3 3 4 4 5 5

Station 1 will the beginning of the filter at the initial entry position. Station 1 will the beginning of the filter at the initial entry position. Accordingly, the pollutants will flow along the increasing station numbers Accordingly, the pollutants will flow along the increasing station numbers until they reach Station 5. Station 5 would be our output position.until they reach Station 5. Station 5 would be our output position.

Further ExplanationFurther Explanation

So, when we are dealing with station numbers are recognizing the position So, when we are dealing with station numbers are recognizing the position in the filter we see according to our arbitrarily defined numbers, right?in the filter we see according to our arbitrarily defined numbers, right?

Not exactly! There is a bit of matrix mathematics behind our station Not exactly! There is a bit of matrix mathematics behind our station numbers. In the Matlab code we can change the number of radial and numbers. In the Matlab code we can change the number of radial and axial collocation points.axial collocation points.

- Our radial points will remain stationary at three, while axial will change - Our radial points will remain stationary at three, while axial will change from 3 to 5.from 3 to 5.

So, what we get is a 3x3 or 3x5 matrix. These will be generated in the So, what we get is a 3x3 or 3x5 matrix. These will be generated in the following way.following way.

[1 3 5][1 3 5] [1 3 5 7 9][1 3 5 7 9]

[2 4 6][2 4 6] [2 4 6 8 10] The bottom row is [2 4 6 8 10] The bottom row is important.important.

[7 8 9][7 8 9] [11 12 13 14 15][11 12 13 14 15] We see our “positions” We see our “positions”

* 10 11* 10 11 * 16 17 18 19 according to these * 16 17 18 19 according to these numbers.numbers.

So, for our 3x3 Matrix we have an input(*), middle position(10), and So, for our 3x3 Matrix we have an input(*), middle position(10), and output(11).output(11).

PlottingPlottingWe plot various pollutants at We plot various pollutants at

different stations to examine different stations to examine the amount of time it takes to the amount of time it takes to reach steady state.reach steady state.

Steady state is just another way Steady state is just another way of saying that our input is of saying that our input is equal to our output. (So, the equal to our output. (So, the GAC is not absorbing any GAC is not absorbing any pollutants at this point.)pollutants at this point.)

Notice that our X axis is C/C0 or Notice that our X axis is C/C0 or input/output. Then, we see input/output. Then, we see when our model reaches when our model reaches steady state by noticing when steady state by noticing when the curves reach 1.the curves reach 1.

The Y axis is just our way of The Y axis is just our way of defining time without units.defining time without units.

Station 10, our “middle” position, reaches Station 10, our “middle” position, reaches a steady state around .15.a steady state around .15.

Station 11, the output, reaches steady Station 11, the output, reaches steady state around .25.state around .25.

Plotting (continued)Plotting (continued)There are a few things to notice There are a few things to notice

here.here.

First, looking at our second First, looking at our second pollutant/component in this pollutant/component in this graph. You can see this by graph. You can see this by glancing at the legend in the glancing at the legend in the bottom right, and noticing bottom right, and noticing different station numbers.different station numbers.

Also notice that our Also notice that our Dimensionless Time stretches Dimensionless Time stretches all the way to 3.all the way to 3.

This is important because in This is important because in comparison, this particular comparison, this particular pollutant gets absorbed by our pollutant gets absorbed by our Carbons much slower than our Carbons much slower than our last graph.last graph.Why does this take so much longer to reach steady state?Why does this take so much longer to reach steady state?

- Well, one major factor is the diffusion coefficients:Well, one major factor is the diffusion coefficients:

DS=DS= [7.99E-09 1.36E-09] Surface diffusion coefficient, (cm^2/s)

DP=DP= [6.80E-06 6.23E-06] Pore diffusion coefficient, (cm^2/s)

ComparisonComparison

Just to demonstrate a few subtle changes. Just to demonstrate a few subtle changes.

The LEFT picture is with 3 axial points, graphing the output station (11) of The LEFT picture is with 3 axial points, graphing the output station (11) of component 1 vs the ouput station (22) of component 2.component 1 vs the ouput station (22) of component 2.

The RIGHT picture is with 5 axial points, graphing the outputs respectively.The RIGHT picture is with 5 axial points, graphing the outputs respectively.

- We want to notice that either there is no change, or a change so small it isn’t - We want to notice that either there is no change, or a change so small it isn’t recognizable.recognizable.

Chloroform (11), Trichloroethene (22)

The Pollutants The Pollutants CHClCHCl33 Chloroform Chloroform CHBrCHBr22Cl Cl

ChlorodibromoethaneChlorodibromoethane BrCHBrCH22CHCH22Br 1,2 DibromomethaneBr 1,2 Dibromomethane CHBrCHBr33 Bromoform Bromoform CC22HClHCl33 Trichloroethene Trichloroethene CClCCl22 Tetrachloroethene Tetrachloroethene CC77HH88 (C (C66HH55CHCH33) Toluene) Toluene

Hazardous TraitsHazardous Traits

Most of the pollutants we have been Most of the pollutants we have been concerned with have the same traits. concerned with have the same traits. They may cause: They may cause:

n In Short term ExposureIn Short term Exposure::(Depression in the central nervous, respiratory, and/or circulatory systems(Depression in the central nervous, respiratory, and/or circulatory systemsDrunk- like systems including dizziness, fatigue, and headaches)Drunk- like systems including dizziness, fatigue, and headaches)

n In Long Term ExposureIn Long Term Exposure::(Liver and/or Kidney damage, Cancer, High Miscarriage rates (tetrachlorethene), (Liver and/or Kidney damage, Cancer, High Miscarriage rates (tetrachlorethene),

Sperm Damage (1,2 Dibromoethene))Sperm Damage (1,2 Dibromoethene))

n Extreme Cases of ExposureExtreme Cases of Exposure::( Blisters and sores in mouth or stomach ulcers (Dibromoethene), respiratory and/or ( Blisters and sores in mouth or stomach ulcers (Dibromoethene), respiratory and/or circulatory system depression,circulatory system depression, DEATHDEATH))

Compound Initial Concentration

(u-mol/L)

K[(u-mol/g) (L/u-mole)1/n]

1/n Film Diffusion

KFX10+2

(cm/s)

Surface Diffusion

Dsx10+9

(cm2/s)

Pore Diffusion

Dpx 10+6

(cm2/s)

Chloroform 22.97 30.4 .5325 1.15 6.10 6.80

Chlorodibromethane 22.55 96.0 .5170 1.13 2.10 6.60

1,2 Dibromoethane 31.49 118.5 .4808 1.13 2.10 6.55

Bromoform 18.84 160.5 .5692 1.12 .915 6.51

Trichloroethene 29.14 196.6 .4163 1.09 1.43 6.23

Tetrachlorethene 17.57 650.6 .4579 1.03 .266 5.61

Kinetic Parameters

Compound Initial Concentration

(mg/L)

K 1/n Film Diffusion

KF

(cm/s)

Surface Diffusion

Ds

(cm2/s)

Pore Diffusion

Dp

(cm2/s)

Trichlorethylene .20 (1.206 u-mol/L)

60.100 .416 3.61x 10-3 1.33x 10-10 6.42x 10-6

Toluene .20 (2.17 u-mol/L)

84.820 .384 3.38x 10-3 8.19x 10-10 5.86x 10-6

Tetrachloroethylene .20 (1.522 u-mol/L)

245.600 .458 3.38x 10-3 3.19x 10-11 5.86x 10-6

Parameters Cont.

Note:• Our program uses micro-molars (µmol/L ) for Co parameters•

ExampleExample

For Toluene:For Toluene:

GAC InterfaceGAC Interface

Minimizing Minimizing needed input needed input from the user from the user

while while providing an providing an professional professional

interface was interface was the main the main objectiveobjective

Summary

Found dimensionless equations to analyze the accumulated pollutants.

Observed resulting pollutant build-ups while using both water and air as a medium.

Created a simple graphic interface where only specific parameters need to be inputted to observe a model of the output.

Analyzed the impact of many different pollutants on the GAC filter.

Conclusion

The next step: further increase the functionality of the user interface and add capacity for more pollutants to be used.

Another future enhancement: adapt the interface to accept varying pollutant concentrations at the input