Wet ESP Control of Fine PM and Condensables · 30ppm –SO3. 100 mg/m3-PM2.5. Point “B ... Mid-High Sulfur Coal z Investigated Control of:

3/23/2010 1Copyright © Siemens Energy, Inc. 2010

Wet ESP Control of Fine PM and Condensables

James “Buzz”

Reynolds Siemens Environmental Systems & Services

LADCO WorkshopMarch 24, 2009


Outline

PM2.5 Regulations

What is PM2.5

Wet ESP Technology

Installations & Results


New EPA PM Standards Require Control of PM2.5

New Source Performance Standards for PM - 2/9/06–

24 hr standard is 0.030 lb/MMBtu –

Proposed changing to 0.015 lb/MMBtu

National Ambient Air Quality Standards PM2.5 - 12/20/05–

24 hr standard is 65 µg/m3 24 hr–

Proposed changing to 35 µg/m3

24 hr–

Proposed a new PM10-2.5

70 µg/m3 standard –

Proposed eliminating the existing PM10 standard

Clean Air Visibility Rule (Regional Haze) - 6/15/05–

BART required on sources that impair visibility–

156 Federal Class 1 areas affected –

Controls for NOx, SO2

, PM and VOCs will be required

State Opacity Regulations–

Typically require < 20%


What is PM2.5

?

Filterable Particulate–

<2.5 microns in size–

Exists as solid particulate at temperatures of 250°F or higher–

Collected in “front-half”

filter of PM test apparatus–

Represents @ 25% of PM2.5

emitted by sources

Condensable Particulate –

<2.5 microns in size –

Vapors that condense at ambient temperatures•

SO3

– H2

SO4

sulfuric acid mist •

Toxic metals –

cadmium, chromium, lead, magnesium–

Collected in “back-half”

impingers in PM test apparatus –

Represents @ 75% of PM2.5

emitted by sources–

Has not been required to date to meet PM10

standards


PM2.5

vs. PM10


2.0µm(Bacteria)

8.0µm(Red Blood Cell)

Particle Sizes

40µm(Naked Eye Visibility)

0.3µm(acid mist)


Particle

Size

Number of Particles

=1/(4/3πr3)

Compared to 10

microns

Surface Area of Particles= P# * 4πr2

Compared to 10 microns

0.5 128,850,993,811,609 8000x 153,846 20x

1 16,106,374,226,451 1000x 76,923 10x

2.5 1,030,807,950,493 64x 30,769 4x

5 128,850,993,812 8x 15,385 2x10 16,106,374,226 7,692

# of Particles in 1 Cubic Inch


Blue Plume Associated with SO3

and PM2.5


Opacity is a Function of Particle Size0.5 micron particles are at peak of light extinction curve


Point “A”30ppm –SO3100 mg/m3-PM2.5

Point “B”Required 10% Opacity

Point “B1”±94% Removal

SO3

& PM2.5

Determine Opacity


Wet Scrubber Removal of PM2.5


How to Collect Small Particles

Size in microns

Feet Gravitationa

l Forces

Centrifugal Forces

Electrical Forces

Brownian Forces

10.0 3.28 x10-5 0.024 20.5 0.98 0.0000057

1.0 3.28 x10-6 0.00027 0.235 0.11 0.0000194

0.1 3.28 x10-7 0.0000069 0.0059 0.27 0.0000927

0.01 3.28 x10-8 0.00000053 0.00046 2.12 0.0008540

Particle displacement due to various forces-Buffalo Fan handbook


Why Wet Electrostatic Precipitation?

Multi-Pollutant Control–

PM2.5

–

SO3

–

Metals

–

Mercury (species dependent)

Opacity Reduction–

<10% visible plume

Operationally–

Low Pressure Drop –

No Moving Parts–

Self-Cleaning –

Small Footprint–

Flexible to Upset Conditions–

No impact on upstream equipment

A Final Polishing Device


BOILERAIR

PREHEATERFGD

SCR

+ -

WESPDRY

ESP/FF

WESP Controls SO3 + PM2.5 + Hg

NOx

PM10Hg

SO2PM10-2.5Hg

SO3PM2.5Hg

NOxSOxPMHg


Wet ESP History

First ESP was wet, not dryDeveloped by Dr. Cottrell in 1907Used to control sulfuric acid mistFirst dry ESP was in 1922 at Detroit EdisonThousands of industrial applicationsUtility installations are limited–

3 in US–

2 in Canada–

@ 25 in Japan –

@ 12 in Europe


IONIZINGELECTRODE GAS

MOLECULESIONIZED

CORONADISCHARGE

CURRENT METER

HIGH VOLTAGETRANSFORMER

mA

•Gas ions formed by high voltage corona discharge•Particles charged by bombardment of gaseous ions•Ions transport particles to collector•Particle charge given up to collector•Particle trapped in liquid film•Collector continuously cleaned

Wet Precipitation Process

PARTICLEENTERS PARTICLE

COLLECTED

PARTICLECHARGED

PARTICLEIRRIGATEDFROM WESP

COLLECTOR PLATE

CHARGE RETURNS TO TRANSFORMER

1-Charging2-Collection3-Cleaning


Wet ESP vs. Dry ESP

OPERATIONAL ISSUES DRY ESP WET ESPBACK CORONA YES NORE-ENTRAINMENT YES NOPM10 REMOVAL YES NOPM2.5 REMOVAL Limited YESSO3 REMOVAL NO YES

MERCURY REMOVAL NO YESWASTE WATER TREATMENT NO YES


Condensables-

Temperature Impact

Dry ESP

–

Unsaturated Flue gas

–

After Air Heater

–

~

325 F

Wet ESP

–

Saturated flue gas

–

After FGD

–

~

130 F SO3

Conversion to Sulfuric Acid Vapor (8% moisture)Reference: Estimating Sulfuric Acid Aerosol Emissions from Coal-Fired Power Plants, R. Hardman, et. al.,U. S. Department of Energy-FETC Conference on Formation, Distribution, Impact, and Fate of

Sulfur Trioxide in Utility Flue Gas Streams, March 1998


WESP

CLEAN GAS OUT

Scrubber/WESP

Combination

FGD SCRUBBER


Collected Liquid to Recycle or Disposal

Horizontal Plate

Type WESP

Plate Irrigation

Inlet Field Outlet Field


Industries

Chemical PharmaceuticalPetro-ChemicalTextile/CarpetFood ProcessingMiningSteelFiber OpticsHazardous Waste Soil RemediationArson ForensicsWood ProductsMedical Sterilization


Eastman ChemicalKingsport, TN

Hazardous Waste

EPA HWC MACT Issued 1999Phase I -2003*

Equipment -Quench-Scrubber-WESP


MACT Test Results

Pollutant Units Test Runs Limits % Particulate gr/dscf, 7%O2 0.0024-0.0030 0.015 99.94

HCL/Cl2 ppmdv, 2.96-4.84 77 99.95

Chromium ug/dscm 39.7-42.8 97 99.97

Lead ug/dscm 3.59-3.85 240 99.95

Mercury ug/dscm 1.82-1.98 130 79%

Dioxin/furan ng TEQ/dscm 0.0131-0.0892 0.4 N/D


Kyanite MiningRichmond, Va.

Ore Mining

State RegulationsOpacity <5%

Equipment Supply-Cyclone-Wet Scrubber-Wet ESP


Test Results

Pollutant Units Inlet Outlet % SO2 ppm 3580.07 21.4 99.4 ACID MIST (H2SO4)

gr /dscf 0.228 0.0159 93.0

PM2.5 gr /dscf 1.6 0.006 99.6 NOx ppm 41.1 21.5 47.7 CO pm 640.63 581.6 9.2 CONDENSED,INORGANIC

gr/dscf 0.13102 0.0143 89

CONDENSED,ORGANIC

gr/dscf 0.14148 0.01573 90

THC ppm as carbon

225.3 85.5 62

Opacity > 50% <5%


First Energy’s Bruce Mansfield Plant

3 x 800 MW UnitsMid-High Sulfur CoalInvestigated Control of: Investigated Control of:

••

PMPM2.52.5

, SO, SO33

, Hg, Hg

••Current Opacity >50%Current Opacity >50%••Opacity Required <20% Opacity Required <20%


Minimum Power

Maximum Power

View Through Observation Tube

Effect of increasing power with a fixed SCA

Coal Fired Utility Pilot 19’

Long Site Tube to Simulate Stack Exit

Medium Power

No Power On

Medium Power

Full Power


Pilot results plotted on Iso-Opacity Chart

NOV 01 INLET

PM2.5 -

116.0 mg/.m3

SO3 -

10.01 ppmv

NOV 01 OUTLET

PM2.5 -

5.0 mg/.m3

SO3 -

0.85 ppmv

SEP 01 INLET

PM2.5 -

67 mg/m3

SO3 -

11.50 ppmv

SEP 01 OUTLET

PM2.5 –

14.4mg/m3

SO3 –

2.70 ppmv

NOV 02 INLET

PM2.5 -

115.0 mg/.m3

SO3 -

8.90 ppmv

NOV 02 OUTLET

PM2.5 -

5.0 mg/.m3

SO3 -

2.90 ppmv


Summary

Wet Electrostatic Precipitation Technology:

Old, well established technology Purpose is to capture PM2.5- solid particulate, acid mists, metals including some mercuryOperates in a saturated, wet environment after a wet scrubberInstalled in a variety of industries Very high removal efficiencies possible > 95% Low maintenance & pressure drop

Documents

Wet ESP Control of Fine PM and Condensables · 30ppm –SO3. 100 mg/m3-PM2.5. Point “B ... Mid-High Sulfur Coal z Investigated Control of: