McIlvaine “Hot Topic Hour” April 14 2011April 14, 2011

Mercury Oxidation Test Program Results

Presenter:John Cochran

CERAM Environmental, Inc.+1 913 239 9896

Co-Author:Andreas Klatt

Porzellanfabrik Frauenthal (CERAM)+49 9574 651277

john.cochran@ceram-usa.com andreas.klatt@frauenthal.net

Presentation Topics

Main Reactions on SCR Catalyst Mercury Oxidation Characterization and

O ti i ti T t POptimization Test Program Test Plan and Objectives Pilot Bench Full Scale Results Pilot, Bench, Full Scale Results Simulation Modeling Results

Representative Full Scale Results Low Temperature Mercury Oxidation

Example of Flue Gas Cleaning System in Power PlantsHg0, Hg2+, Hgp, HCl– Species at Boiler Outlet

Wet FGD

Flue Gas

g , g , gp, pImportant for Removal in Flue Gas Cleaning

SCR ESP or baghouse

~700°FCoal & Combustion Air

Hg0

>2500°FFly AshAir Heater

HCl

FGD-Products/Residuals

Use Existing Flue Gas Cleaning Systems for Mercury Removal- Hg Oxidation on SCR CatalystHg Oxidation on SCR Catalyst- Removal of Particulate Hg (ESP, baghouse)- Separation and Removal of Oxidized Hg in FGD

Clean Air Mercury Rule (CAMR) – Reduce Hg Emissions (≈48 tons/yr Uncontrolled in U.S.) Combination of high-dust SCR/ESP/FGD may result in Hg removal up to 95% Combination of high dust SCR/ESP/FGD may result in Hg removal up to 95%

Important Step: Hg0-Oxidation on SCR Catalyst

SCR DeNOx Reaction – Process Basics

Catalyst Active Sites Constantly Being y y gRegenerated in a Cycle

1. Active Site Available2. Adsorb Ammonia3. Reaction of NOx With NH34. Regenerate Site With O2

Active Sites Not Busy With NOx Reduction (Ammonia) Available For Oxidation of SO2, Hg0, Unburned H d b VOC Di i tHydrocarbons, VOC, Dioxins, etc.

Hg Oxidation With Titanium/Vanadium SCR-Catalysts

Langmuir-Hinshelwood-Mechanism at adjacent active

1Mechanism at adjacent active sites

1. HCl adsorb onto V sites2. Reactive Cl generated4 g3. Weakly adsorbed Hg0

4. O2 re-oxidizes active sites Deacon Reaction

2

4

Deacon Reaction 1. V2O5 and HCl React to

Produce Cl2 Which Reacts With Hg0

Source: Energy & Fuels, 2009, Zhou et al..

2 Hg + 4 HCl + O2 → 2 HgCl2 + 2 H2O3gy

Oxidation Rates Vary Based on Location in the Reactor

Ammonia Concentration Decreases as Flue Gas Flows Down Through Catalyst LayersNH3 Catalyst Layers Surplus or “Free” Active Sites

Increase Down Through Reactor Surplus Active Sites Result inta

lyst

NH3ppm

Surplus Active Sites Result in Increasing Rate of… SO2 to SO3 Oxidation Mercury Oxidationst

ance

Dow

n C

at

Mercury Oxidation Dependent on Catalyst Aging

Dis

“Free” Active Sites

SO2

SO3Hg0

Hg2+

Halogen

CERAM Participating in Comprehensive Mercury Oxidation Test ProgramsMercury Oxidation Test Programs

CERAM Working to Optimize Mercury Oxidation Potential in Extensive Pilot/Demonstration Programs

European Research Project DENOPTResearch Fund for Coal and Steel RFCR-CT-2007-00008

Participants - ENEL, E.ON, EnBW, CERAM, Reaction Engineering, p g gUniversity of Stuttgart, and RECOM Service

Test Approach: Evaluating Different Catalyst Compositions Evaluating New, Deactivated, and Regenerated

Catalyst Bench and Pilot Scale Tests Full Scale Tests (600 MW PC) When Firing Coal

and Co-Firing Coal and Biomass CERAM is the Only Catalyst Supplier Participating

CERAM Participating in Comprehensive Mercury Oxidation Test Programsy g

Program Objectives: Fully Characterize Oxidation Reactions – Develop Mathematical Model Evaluate Commercial and Innovative Low and High Temperature Catalyst Evaluate Commercial and Innovative Low and High Temperature Catalyst

Compositions Directed at Promoting Mercury Oxidation Assess Catalyst Effects on Mercury Speciation for Different Coals Investigate Effects of Operating Conditions (Area Velocity Catalyst Age Investigate Effects of Operating Conditions (Area Velocity, Catalyst Age,

and Deactivation Levels) on Oxidation Rate Optimization of SCR Catalyst Performance Related to Mercury Oxidation

and Limiting Deactivationg Program DENOPT completed June 2010

Research has Expanded CERAM’s Knowledge Base Regarding Hg Oxidation Reaction Mechanisms and Kinetics

Second Program DEVCAT (DEVelopment of High Performance SCR CATalyst Related to Different Fuel Types) started July 2010 (ongoing for three years) Hg0

Hg2+

H lHalogen

I fl f HCl i

Micro-scale Reactor Tests on Different Catalysts

Influence of HCl-concentration

60%

70%

N1

20%

30%

40%

50%

Hg‐con

version [%

]

0%

10%

0 50 100 150 200 250 300

HCl‐concentration  [mg/Nm3]60%

20%

30%

40%

50%

g‐conversio

n [%

]

0%

10%

20%

0 20 40 60 80 100 120 140 160

Hg

HCl‐concentration [mg/Nm3]HCl concentration  [mg/Nm3]

Influence of Molar Ratio NH3/NOx3

Hg-Oxidation an CERAM-Wabenkatalysatoren

100

80

90

100

AV1

AV2

%

50

60

70

tions

grad

[%]

AV1 < AV2390°C

Oxi

datio

n, %

20

30

40

Oxi

dat

Mer

cury

0

10

0 0,2 0,4 0,6 0,8 1 1,2Molverhältnis NH /NO

Hg-Oxidation and NO-Reduction are competing reactions

Molar Ratio NH3/NOxMolverhältnis NH3/NOMolar Ratio NH3/NOx

Tests Results for 500kW Test Rig5

O2] Hg ionic Hg elemental

5

O2] Hg ionic Hg elemental

Coal – Catalyst 1 Coal – Catalyst 2

3

4

n [µg/m

3@ 6% O

3

4

n [µg/m

3@ 6% O

1

2

Hg‐concen

tratio

1

2

Hg‐concen

tration

0

inlet first layer

second layer

third layer

0

inlet first layer

second layer

third layer

18

20ionic elemental

coal + sludge

18

20ionic elemental

coal + sludge + NH3

10

12

14

16

10

12

14

16

0

2

4

6

8

0

2

4

6

8

r

0

inlet middle outlet0

inlet middle outlet

Note: Test Results for High Area Velocity Not Typical for Full Scale

Influence of Space Velocity (SV)

90

100C-1 FS_02_N FS_02_ES

Sli S R

60

70

80Slip Stream Reactor600 MW PC BoilerLow Chlorine Coals

40

50

60

Hg_

ox %

10

20

30

Source: ENEL

01000 3000 5000 7000 9000 11000 13000 15000

SV (h-1)

Power Plant Measurements600 MW PC Boiler600 MW PC BoilerHigh-Dust SCR3 Honeycomb Catalyst LayersHigh Chlorides (~900 ppm in coal)High Chlorides ( 900 ppm in coal)

yst L

engt

h CatalystLayer 1

Cat

aly

Catalyst

Layer 2

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

Catalyst

Layer 3

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%oxidized mercury share [%]

Power Plant Measurements

2nd Measuring CampaignCoal Chlorine 62 ppmSulfur 0.43%

Implementation into Simulation Model

Use Existing 3D-CFD Simulation Model for Boiler Developing and Applying New Model for SCR system Implementation of Catalyst Chemistry (NOx, Hg, SO2/SO3 conversion)

NH I j ti

Input Data from Full-scale and Lab Measurements for Model Validation

NH3-Injection

Catalyst Layer 3

Catalyst

Assessment of Model Predictive Quality

Hg Oxidation Rate along Reactor

Assessment of Model Predictive Quality (2)

Hg Oxidation Rate along Reactor

Mercury Oxidation Kinetic Model

HCl contentincreasing AV

HCl content

Representative U.S. Results for CERAM Catalyst

Plant 1 Plant 2 Plant 3

NOx Removal >91% >90% >92%

Coal S lf r >3% >3 5% >3 5%Coal Sulfur >3% >3.5% >3.5%

Coal Chlorine 0.13% 0.15% >0.1%

Operating Temperature 700 F 720 F 770 F

SO2 to SO3 Conversion Rate Across Reactor

<0.5% <0.5% <0.5%

Catalyst Layer Design 3+1 3+1 2+2

Catalyst Age 4,000 hr (3) 4,000 hr (1)21,000 hr (3)

21,000 hr (2)

Mercury Removal >95% >80% >85%

SummaryCERAM P ti i ti i C h i L T M O id ti CERAM Participating in Comprehensive Long Term Mercury Oxidation Characterization and Optimization Test Program DENOPT Program Complete DEVCAT Program Ongoing Thro gh 2013 DEVCAT Program Ongoing Through 2013

Mercury Oxidation Reactions are Complex and Vary as a Function of… Flue Gas Composition (HCl, Other Halogens, SO2, etc.)

R t O ti C diti (NH /NO A S V l it Reactor Operating Conditions (NH3/NOx, Area or Space Velocity, Temperature, etc.)

Catalyst Composition Surplus Reactor Potential Present Surplus Reactor Potential Present Exposure to Flue Gas (Catalyst Aging) Mercury Oxidation Possible with Low SO2/SO3 Oxidation Catalyst

Si l ti M d l D l d t B tt P di t P f Simulation Model Developed to Better Predict Performance Low Temperature Mercury Oxidation Process is Developmental but

Promising