2012 PNWIS PM 25 Presentation KMD v3

Source Emissions Testing and Emissions Specialists

Kevin DonahoeKevin DonahoeThe Avogadro Group, LLC

PNWIS November 8 2012PNWIS November 8, 2012Portland, Oregon

Key Points

y What is particulate matter?

y What are we trying to measure?

y Methodology and Results

y Conclusions and Implications

TAKE NOTE

y A POLLUTANT IS NOT DEFINED BY THE CHEMICAL OR PHYSICAL CHARACTERISTICS OF THE POLLUTANT (e g PHYSICAL CHARACTERISTICS OF THE POLLUTANT (e.g. PM2.5, CPM)

y IT IS DEFINED BY THE SAMPLING METHODOLOGY USED TO COLLECT THE POLLUTANT (and the sampler?)

What is Particulate Matter?

y Primary Particulatey Filterable PM (primary front half)Filterable PM (primary front half)

y Solid or liquid material at stack conditions TSP, PM10 , & PM2.5y Methodology well-established no problems

y Condensable PM (primary back half)Vapor or gas at stack conditionsy Vapor or gas at stack conditions

y Condenses and/or reacts upon cooling and dilution in ambient air to form solid or liquid PM immediately after stack discharge

y Precursors are organic and inorganicy Common measurement bias involves inorganic (e.g. ammonia and SO2)g ( g 2)y All assumed to be in the PM2.5 size fractiony Source testing methods attempt to duplicate complicated formation process

y Secondary Particulateyy Forms by chemical reactions in atmosphere downstream of

release point, but not immediately

y Question: Can we separate the two?y Question: Can we separate the two?


ParticulatePrimarySecondary PrimarySecondary

Condensable FilterableTSPTSP

PM10PM10PM2.5




PM10A h d

PM10PM2.5

EPAMethod5TestSourceTest




PM10A h d /

PM10PM2.5

EPAMethod5/202SourceTest




PM10h d

PM10PM2.5

EPAMethod201A/202SourceTest




PM10b l

PM10PM2.5

AmbientSamplerBasisforNAAQS

What are we trying to measure?

Primary PM2.5 Emissions- Particles

Photochemistry other Gases (precursors) to Secondary PM2.5 and to smog (ozone, etc.)

P GSP

PC

P

smog

- Some Gases form Condensable PMg ( , )

G

Gsmog

G SGC

C

GCP G

CP

Ambient MonitorUnder stack conditions

SSGGSGS

SC

C

PG

PG

Ambient MonitorCollectsParticles,Condensables &S d

Under stack conditionsWe measureParticles & GasesP Secondary

Primary PM2.5 Emissions- Particles (solid, liquid)

G GG

- Condensables

Old EPA 202 Test Method

Why Old EPA 202 is problematicy Does not accurately emulate stack releasey Gases bubbled through water dissolved into g

solutiony Dissolved gases form salts that may or may not form

naturally when released to atmospherenaturally when released to atmospherey Although some back-half PM may actually be CPM or

primary PM2.5 emissions, much can be an artifact of the methodmethod

y Nitrogen purge works very well for high SO2sources but is only optional!sources but is only optional!

y Other optional analytical procedures varied results between sources/testersresults between sources/testers

New Dry 202 (formerly OTM-028)( d d i i d b k filt )(uses condenser, dry impingers and backup filter)

New Dry 202 (formerly OTM-028)

New Dry Method 202 (OTM-028) y Objectives

y Less artifacty Fewer variables (eliminate options)e e a ab es (e ate opt o s)y More consistent results

y Procedural Changesy Water insulated condenser coily Water-insulated condenser coily First impinger is short-stem dropout varietyy First two impingers are dry at beginning of test run

o Condenser and impingers cool sample to 85 F or lowerp g po Gas does not bubble through excess water or condensateo Condensables recovered from coil, dry impingers and CPM filter

y CPM filter added after 2nd impingerM d i di l d SOy Mandatory nitrogen purge to remove dissolved SO2

y Impingers after filter are not recovered (moisture content only)y Extraction solvent - MeCl2 is replaced with hexaney Glassware is bakedy Glassware is baked

Early Tests: OTM-028CPM emissions by EPA 202 and OTM-028

Logarithmic Scale

0.100

0 010

0.100

/

M

M

B

t

u

EPA 202

OTM 0280.010

s

s

i

o

n

r

a

t

e

,

l

b

/

Pow er(EPA 202)

0.001

C

P

M

e

m

i

s

Pow er(OTM 028)

0.0000.1 1 10 100

SO2 concentration, ppm vol dry

These are results from a variety of sources, 2007 to 2009 with trend lines for each of the two methods. OTM-028 (draft 202) results were higher than Old 202 for low-emitting sources with low SO2.

More Recent Dry Impinger ResultsCPM emissions by EPA Old 202 and New 202

Linear Scale, vs. SO2

0.025

0.030

M

M

B

t

u

Old 202

0.015

0.020

n

r

a

t

e

,

l

b

/

M

New 202

Linear (Old 202)

0.000

0.005

0.010

e

m

i

s

s

i

o

n

These are results from 2010 and 2011 distributed according to SO2. The

0.0000 5 10 15 20

C

P

M

e

SO2 concentration, ppm vol dry

g 2New and Old 202 gave similar results and neither trended with SO2. There are results around 0.010 and around 0.001 throughout the range.

CPM Emissions by Old and New EPA 202Gas-Fired Plants Only

0.0018

Gas Fired Plants OnlyOld 202 New 202 Linear (Old 202) Linear (New 202)

0 0012

0.0014

0.0016

M

B

t

u

0 0006

0.0008

0.001

0.0012

C

P

M

l

b

/

M

M

0

0.0002

0.0004

0.0006

00 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45

SO2 Concentration, ppm vol dry

Datafromjustgasfired boilersandgasturbines;someoftheSO2concentrationsshownareestimated.LittledifferenceOld/NewMethod.

CPM vs. vs. SO2

CPM vs.

NH3NH3

Is the new method better?y Did EPA meet its objectives?

y Results seem less variabley Less artifact at high SO sources; inconclusive at low SO sourcesy Less artifact at high SO2 sources; inconclusive at low SO2 sourcesy More recovery fractions add potential for contamination or bias

y Can we improve the situation?py Improve blank levels, update lab proceduresy More fractions add complication to analysis

y Reduce Ammonia Slip (below about 2 ppm)p ( pp )y Correct the results for ammonium saltsy some have suggested using controlled condensation test results for the

inorganic fractiony Use a Dilution method (measure filterable and condensable

together)y EPA conditional test method CTM-039

ASTM dil i h d y ASTM dilution method

Dilution Sampler ConceptStack emissions of Primary PM2.5Emissions into a "virtual" stream of air

PhotochemistryParticles Secondary + Primary PM2.5+ Condensables

Stream of air + Gases

Ambient sampler PM2.5 filter

Stack sampling of Primary PM2.5 by CTM-039Sample "emitted" into a stream of air

Primary PM2.5 - Particles and Condensables (and Gases)

Sampled through filtersame as Ambient sampler

Stream of air Gases remain as gases, no secondary PM2.5

CTM-039

y Designed to emulate dilution of stack emissions in gambient air

y Condensables form in the same way as in actual y Condensables form in the same way as in actual emissions EPAs Gold Standard

P i PM2 5 ti l d CPM ll l d y Primary PM2.5 particles and CPM - all sampled together no secondary collection

y Shows promise the results of comparative studies are encouraging

y Disadvantage: New, Rare, Expensive, Bulky

l f / ( ) b h l l bl k l l l d f l hAresultof1mg/m3(CCGT)isaboutthesamelevelasablanksample.BoilersweresolidfuelwithSNCR.BoilerAwastestedoncebyNew202withtheammoniainjectionoff.CTM039canreduceartifactandthereforeprovidelowerresultsinsomecases.

Conclusionsy The new method is advantageous only in certain cases, usually at higher

concentrations of SO2 or other CPM precursor gases

y New 202 is sometimes only a slight improvement from the Old 202 for low-concentration sources

y New 202 might not be worth its extra cost- except in some cases (sometimes every little bit helps)

Oth lt ti ( h CTM 039) ill t b t id y Other alternatives (such as CTM-039) will cost even more - but may provide more representative results for some cases

y Results will depend on which gases are present (NH SO SO HCl) and in y Results will depend on which gases are present (NH3, SO2, SO3, HCl) and in what relative concentrations

y The Method used will define the Resultsy The Method used will define the Results

y Quality Testing is critical!

Questions?

Kevin DonahoeKevin DonahoeDistrict Manager, Portland

Source Emissions Testing and Emissions SpecialistsSource Emissions Testing and Emissions SpecialistsPortland, OR Phoenix, AZ - Antioch, California Medford, OR

2012 PNWIS PM 25 Presentation KMD v3

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