# Presentation: 891773

## Control of Mercury Emissionsby Injecting Powdered Activated Carbon (PAC)

**Control of Mercury Emissions****by Injecting Powdered Activated Carbon (PAC)**

**Michael D. Durham, Ph.D., MBA**
**ADA Environmental Solutions**
**8100 SouthPark Way B-2**
**Littleton, CO 80120**
**303 734-1727**

**Presentation to **
**Utility MACT Working Group**
**May 13, 2002**
**EPA, RTP, NC**

## Outline

** ****ADA-ES DOE/NETL Hg Control Program**
**Background on PAC Injection Technology**
**Results from PAC with an ESP**
**Results from PAC with a FF**
**Conclusions and Future Plans**

## Full-scale field testing of sorbent-based mercury control on non-scrubbed coal-fired boilers
Primary funding from DOE National Energy Technology Laboratory (NETL)
Cofunding provided by:
Southern Company 
Wisconsin Electric
PG&E NEG
EPRI
Ontario Power Generation
TVA
First Energy
Kennecott Energy
Arch Coal

**Full-scale field testing of sorbent-based mercury control on non-scrubbed coal-fired boilers**
**Primary funding from DOE National Energy Technology Laboratory (NETL)**
**Cofunding provided by:**
**Southern Company **
**Wisconsin Electric**
**PG&E NEG**
**EPRI**
**Ontario Power Generation**
**TVA**
**First Energy**
**Kennecott Energy**
**Arch Coal**

## Project Overview

**Perform first full-scale evaluations of mercury control on coal-fired boilers (up to 150 MW equivalent).**
**Evaluate effectiveness of sorbent-based Hg control (activated carbon).**
**Test several different power plant configurations.**
**Document all costs associated with Hg control.**

## DOE/NETL Test Sites

_**Test Site**__**	**__**Coal**__**	**__**Particulate **__**	**__**Test**__**	**__**	**__**Control**__**	**__**Dates**_
**Alabama Power****	****Bituminous****	****HS ESP****	****Spring**
**Gaston ****	****	****COHPAC FF****	****2001**
**Wisconsin Electric****	****PRB****	****Cold Side ESP****	****Fall**
**Pleasant Prairie ****	****	****	****2001**
**PG&E NEG****	****Bituminous****	****Cold Side ESP****	****Summer**
**Brayton Point****	****	****	****2002**
**PG&E NEG****	****Bituminous****	****Cold Side ESP****	****Fall**
**Salem Harbor****	****	****	****2002**

## Coal-Fired Boiler with Sorbent Injection and Spray Cooling

## Semi-Continuous Mercury Analyzer

**Chilled **
**Impingers**

**Flue Gas**

**CVAA**

- Mass Flow
- Controller

**Gold Trap**

- Waste

**Heater**

-   **Micro controller **
**with Display**

**Dry Air**

## Sampling Time Required

**Sampling Time Required**

## Comparison of OH and S-CEM*, Long Term Tests (10 lbs/MMacf)

## Capture of Vapor Phase Hg by Solid Sorbents

**Mass Transfer Limits (getting the Hg to the sorbent)**
**Removal increases with particle concentration**
**Produces percentage removal independent of concentration**
**Particle control device (FF vs ESP) is a critical parameter**
**Sorbent Capacity to hold Hg depends upon:**
**Sorbent characteristics**
**Temperature**
**Mercury concentration**
**Concentrations of SO****3**** and other contaminants**

## Equilibrium Adsorption Capacities at 250°FUpstream and Downstream of SO3 Injection

**Equilibrium Adsorption Capacities at 250°F****Upstream and Downstream of SO****3**** Injection**

## WEPCO Pleasant Prairie

**Testing completed fall of 2001**
**PRB coal**
**ESP only**
**Spray cooling**
**SO****3**** conditioning system**

## Slide 13

## Activated Carbon Storage and Feed System

## ESP Configuration, PPPP

## Powdered Activated Carbon Injection System

## Baseline Hg Measurements (g/dscm)

| Location  | Particle Bound  | Oxidized, Hg2+  | Elemental, Hg0  | Total, Hg  |
| --- | --- | --- | --- | --- |
| Inlet ’99 | 0.16 | 2.29 | 6.21 | 8.65 |
|  |  |  |  |  |
| Inlet ‘01 | 1.84 | 2.34 | 11.39 | 15.55 |
|  |  |  |  |  |

## Mercury Trends Week 1

## Response Time for PAC Injection on an ESP

## Carbon Injection Performance on a PRB Coal with an ESP

## Long Term Trend Data

**Long Term Trend Data**

## Speciated Mercury Measured by Ontario Hydro Method (10 lbs/MMacf)

_**	**__**PARTICULATE**__**	**__**ELEMENTAL**__**	**__**OXIDIZED**__**	**__**TOTAL**_
**Baseline****	**
**   ****ESP Inlet****	****        1.97****	****     12.22****	****     2.51****	**** 16.71**
**   ****ESP Outlet****	****        0.01****	****       9.80****	****     6.01****	**** 15.82**
**   **_**Removal Efficiency**__**	**__**        99.5%**__**	**__**     19.8%**__**	**__**   -139.3 **__**	**__**   **__**5.3%**_

**(microgram/dncm)**

**PAC Injection**
**   ****ESP Inlet****	****        0.98****	****     14.73****	****      1.73****	****  17.44**
**   ****ESP Outlet****	****        0.00****	****       4.27****	****      0.44****	****    4.71**
**   ****Removal Efficiency****	****      100.0%****	****      ****71.0%****	****     74.5%****	****  73.0%**

## Alabama Power E.C. Gaston

**Alabama Power Company E.C. Gaston Electric Generating Plant Unit 3, Wilsonville, AL**
**270 MW Firing a Variety of Low-Sulfur, Washed Eastern Bituminous Coals**
**Particulate Collection System**
**Hot-side ESP, SCA = 274 ft****2****/1000 acfm**
**COHPAC baghouse supplied by Hamon Research-Cottrell**
**Wet Ash Disposal to Pond**

## Site Test Configuration with EPRI TOXECON at Alabama Power Plant Gaston

## S-CEM Duct Traverse

## Example of S-CEM Data

## Response Time of PAC Injection with a Fabric Filter

## Mercury Removal vs. Injection Rate

## Pressure Drop Increase from PAC Injection

## Mercury Removal vs. Injection Rate

## 5-Day Continuous Injection

**5-Day Continuous Injection**

## Average Mercury Removal Long-Term Tests Gaston, Ontario Hydro

**(microgram/dncm)**

_**	**__**PARTICULATE**__**	**__**OXIDIZED**__**	**__**ELEMENTAL**__**	**__**TOTAL**_
**Baseline****	**
**   ****COHPAC Inlet****	****        0.09****	****       9.54****	****     5.97****	**** 15.60**
**   ****COHPAC Outlet****	****        0.01****	****     11.19****	****     3.34****	**** 14.54**
**   **_**Removal Efficiency**__**	**__**        89.1%**__**	**__**     -17.3%**__**	**__**     44.1%**__**	**__**   **__**6.8%**_

**PAC Injection**
**   ****COHPAC Inlet****	****        0.23****	****       6.37****	****      4.59****	**** 11.19**
**   ****COHPAC Outlet****	****        0.12****	****       0.91****	****      0.03****	****    1.05**
**   ****Removal Efficiency****	****       45.6%****	****      ****85.7%****	****     ****99.3%****	****  ****90.6%**

## Comparison of Sorbent Costs for a Fabric Filter and an ESP 

## Conclusions (PAC General)

**PAC injection can effectively capture elemental and oxidized mercury from both bituminous and subbituminous coals**
**Additional field tests and long-term demonstrations are necessary to continue to mature the technology**
**Fabric filters provide better contact between the sorbent and mercury than ESPs resulting in higher removal levels at lower sorbent costs**
**New COHPAC FF’s will have to be designed to handle higher loadings of PAC to insure high (>90%) mercury removal**
**Conventional FF’s should not require any modifications for PAC**

## Conclusions (Response to Concentration Variations)

**Response times to changes in inlet concentrations:**
**Feedback data from outlet CEMs—tens of minutes**
**Impact of changes in injection rate:  tens of minutes to hours**
**Long averaging times will be required to recover from upsets**
**Injection at somewhat higher rates will make the technology more capable to handle inlet fluctuations**
**PAC injection lends itself to the use of feed rate parameters as a definition of  Maximum Achievable Control Technology**

## Future Plans

**Short-term testing at additional sites**
**PG&E Brayton Point (Bituminous coal, large ESP) ****	****6/ 2002**
**PG&E Salem Harbor (Bituminous coal, SNCR, large ESP)****	**** 9/2002**
*** TBD  (PRB coal, small ESP)****	**** 3/2003**
*** Southern Company (Bituminous coal, small ESP)****	****8/ 2003**
**Long-term testing**
*******Alabama Power (Bituminous coal, COHPAC FF)****	****2002-2003**
***CCPI Program (PRB Coal, COHPAC FF)****	****2004-2006**
***CCPI Program (Bituminous Coal, COHPAC FF)****	****2004-2006**
***  Proposed**

## For More Information

**www.adaes.com**
**www.adaes.com****/mercury.htm**
**Link to other mercury related web sites**
**Publications/reports**
**www.adaes.com****/MercuryPublic.htm**
**Public information on DOE/NETL ****Mercury Control Program**
**www.netl.doe.gov/products/environment/index.html****  DOE/NETL Website**