Fine PM Emission Factors for Gas Turbine Engines 2014/PMEmissions... · Fine PM Emission Factors...

ICEPAG 2014

April 1-3

Newport Beach, California

Fine PM Emission Factors for

Gas Turbine Engines

Glenn C. England

Principal Consultant

ENVIRON International Corporation

Irvine, California 92629

Overview

• Particulate matter (PM) & regulations

• PM Emissions from gas-fired engines

• Emission factors

• Measurement influences & impacts

April 1-3, 2014 ICEPAG, Newport Beach, CA 2

Why Are Fine PM Emissions from Gas

Turbines Relevant?

• Increasing natural gas use for power generation

• Typical 500 MW NGCC plant “emits” ~30-50 tpy

All submicron aerosols

• New Source Review

10 tons/year PM2.5 Prevention of Significant Deterioration

threshold

• triggers modeling, technology, offset requirements = time, $

Includes filterable and condensable PM

• Impediment to licensing new power plants in

California due to lack of PM10/2.5 offsets

• Evolving interest in human health effects of

“ultrafine” PM and nanoparticle emissions


Hot Filter

Iced Impingers

Cyclones

Impactors Particle counting & size

classification (e.g., SMPS)

“Filterable PM” “Condensable PM”

Traditional stationary source methods

Dilution Methods Traditional mobile source measurement methods & research methods for stationary sources

Particulate Matter

>10 µm 10-2.5 µm

“Coarse PM”

2.5 µm 0.1 µm

(100 nm) 50 nm

PM10 10 µm PM2.5

“Fine PM” “Ultrafine PM” “Nanoparticles”

TSP

mass

number 10,000 nm 2,500 nm 100 nm 50 nm

1960’s 1980’s 1990’s 2000’s 2010’s


PM10 and PM2.5

• Definitions - 40 CFR 51, §51.50:

Filterable PM2.5/PM10 : Particles that are directly emitted

by a source as a solid or liquid at stack or release

conditions and captured on the filter of a stack test train.

Condensable PM: Material that is vapor phase at stack

conditions, but which condenses and/or reacts upon

cooling and dilution in the ambient air to form solid or

liquid PM immediately after discharge from the stack.

• Particulate matter is defined by the test methods

used to measure it!


Natural Gas-Fired Combined Cycle

• Gas turbines & steam

turbines

Brayton+Rankine

“2 on 1” or “3 on 1” blocks

~500-800 MW/block

Duct burners

Thermal efficiencies ~55->60%

April 1-3, 2014 ICEPAG, Newport Beach, CA

• Emissions controls

Lean pre-mix combustors

SCR

• 2-5 ppm NOX limits

CO oxidation catalysts

G

Combustion

Turbine-

Generator

Heat Recovery

Steam Generator

Natural gas

TG

Steam Turbine-

Generator

C T

O2, CO

2

H2O

N2

Duct Burners

CO Catalyst

SCR

6

Air

IGCC with CO2 Separation

Scrubber Sour

Shift

Gasification Block

Gasifier

G

Power Block

O2 Plant

Combustion

Turbine-

Generator

Heat Recovery

Steam

Generator

Coal, Petcoke,

etc.

Air

N2

O2

Low-carbon fuel gas

CO2

Sequestration

Sulfur

Recovery

Slag

T G

Steam Turbine-

Generator

C T

Duct Burners

CO Catalyst

SCR

O2,

H2O

N2

Mercury

Adsorption

Mercury

Recovery


Sulfur

Absorption

CO2

Absorption

PM2.5 Sources

• Incomplete fuel combustion

(carbon conversion to soot,

organics)

• Combustion and post-

combustion conversion of

sulfur (& chlorine) to acid

aerosols & salts

• Vaporization and

condensation of volatile

elements

• Transmission of non-volatile

elements

• Corrosion/erosion of system

components

• Aerosol nucleation,

condensation, accumulation

and breakup

Gas Turbine

(compressor,

combustor, turbine)

Air solids

Air sulfur

Fuel carbon

Fuel sulfur

Fuel solids

SCR reagent

solids

Nitrogen solids

Steam solids

Evaporative

cooler solids

HRSG

(duct burners,

catalysts, boiler)

PM2.5


PM2.5, lb/hr

Rela

tive fre

quency

Effect of CO2 (and S) Separation

PM2.5, lb/hr

Rela

tive fre

quency

Total PM2.5

Solids (including chloride)

Sulfate

OC

EC

Ammonium

Nitrate

NGCC - Natural Gas IGCC - Low Carbon Fuel


PM Measurements - traditional

• Hot filter/impingers

Collect filterable & condensable separately (?)

Dry & weigh filters, evaporate & dry probe/cyclone rinses

Organic extraction, evaporate & weigh impinger residues


EPA Methods

201A/202 (2010)

EPA Method 5

State & local

variations

High bias due to measurement artifacts can be significant

(dissolved gases e.g. O2, SO

2, NH

3, VOC, HCl → solid residues)

Water Bath

Empty “dry”

impingers

Silica Gel

Condenser

(≤30 ºC)

Heated or

in-stack

filter CPM Filter

(20-30 °C)

≤20°C Outlet

Ice

Bath

In-Stack Cyclones

10 &/or 2.5 µm

Gravimetric analysis

tolerance 1 mg each

fraction (5 mg total)

AP-42 PM Emission Factors - GTs

• Ch. 3.1, gas turbines, natural gas (April 2000)

EPA Methods 5 and WDNR 5

5 tests, 4 units 1994-1996

• Total PM 0.0065 lb/MMBtu

cPM is 71% of total

Uncertainty >100%


0

2

4

6

8

10

1 2 3 4 5

mg

/d

scm

cPM

fPM

Measured Gas Turbine PM Emissions


0.00

0.01

0.02

0.03

0.04

0.05SC

SC

SC

SC

SC

SC

SC

SC

SC

CC

, no D

B

CC

, no D

B

CC

, no D

B, N

G/RG

CC

, no D

B, N

G/RG

CC

, D

B off, 53%

CC

, D

B off, 75%

CC

, D

B off, 100%

SC

, LG

66 MW 64 MW 45 MW 24 MW 13.5 MW 13.3 MW 5.7

MW

lb

/M

MBtu

Impinger-total

Impinger-organic

Impinger-inorganic

Probe rinse

Filter

CC=combined cycle

SC=simple cycle

DB=duct burners

NG=natural gas

LG=landfill gas

RG=refinery fuel gas

Impinger catch dominates measured emissions

Measured Gas Turbine PM Emissions


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0.0014

0.0016

0.0018

CC,

no

DB

CC,

DB

on

CC,

DB

off

CC,

DB

off

CC,

DB

on

CC,

DB

off

CC,

DB

on

CC,

DB

off

CC,

DB

on

CC,

DB

off

CC,

DB

on

405

MW

181 MW 176 MW

lb

/M

MBtu

Impinger-total

Impinger-organic

Impinger-inorganic

Probe rinse

Filter

CC=combined cycle

DB=duct burners

Lower emission rate for larger units (?)

Natural gas

Condensable PM Speciation

Method 202 (1991)


0.000

0.002

0.004

0.006

0.008

0.010

0.012

4S

RB

+N

SC

R

RIC

E

4S

LB

RIC

E

Alp

ha

(he

ate

r)

Bra

vo

(p

ow

er

pla

nt)

Ch

arlie

(he

ate

r)

A (

boile

r*)

B (

hea

ter*

)

C (

ste

am

ge

nera

tor)

lb/M

MB

tu

O-CPM I-CPM (SO4=)

I-CPM (NH4+) I-CPM (Cl-)

I-CPM (Na) I-CPM (Ca)

I-CPM (K) I-CPM (other species)

I-CPM (other unspeciated)

157%

98%

130%

85%

133%

77%

128%

141%

Gas fuels

HeaterNGCC Boiler HeaterHeater Boiler4SRB

RICE

4SLB

RICE

Dilution Methods


EPA CTM 039 (2004)

• Stirred jet mixing cone

• Dilution ratio 10-40

• Dilution air <50% RH, 80°F

• Mixing residence time 0.2

sec

• Diluted sample <85°F

• Water & acetone recovery

rinses required

• Method 5 gravimetric

analysis

• 0.1 mg balance

• Evaporate & dry rinses

• Dry & weigh filter

In-Stack Cyclones

10 &/or 2.5 mm

Dilution Methods


Dilution Air

In-Stack Cyclones

10 &/or 2.5 mm

Heated

Probe

Flow

Meters

Mixing

Section

Aging

Section

Bypass

ULPA Filter

Charcoal Filter

Stack

Gas

Fan

PM2.5 Cyclone

(optional)

Flow

Valve

• (Parallel jet mixing)

• Dilution ratio ≥20

• Aging residence time 10 sec

• Diluted sample RH <70%

• PM2.5 cyclone after aging

• Ambient air gravimetric analysis

• 0.001 mg balance, equilibrate @ 20-25°C, 45-55% RH

• Recovery rinses (test or run)

Filter

(and other

media)

ISO 25597 (2013)

Flow

Meters

Dilution Methods vs. 201A/202-1990

• Dilution filter results consistently much lower than

M201A/202-1990 results in side-by-side tests at 7

different gas-fired sources

April 1-3, 2014 ICEPAG, Newport Beach, CA

0.0

0.5

1.0

1.5

2.0

2.5

3.0

201A/202 Dilution (filter) Dilution (filter +rinses)

mg

/ds

cm

3 NGCC's (2001-3)

1 NGCC (2008)

Two different dilution

methods

Modified EPA CTM 39 (2008)

“ISO 25597” (2001-2003)

M202 (1991) iced

impingers

sulfate artifact adds significant

positive bias

Blanks and samples

typically indistinguishable

Concentrations at

measurement “noise” level

17

PM2.5 Emission Factors – Dilution Method

OC accounts for >90% of PM2.5 mass

(but measurement background indicates artifact)


0

20

40

60

80

100

120

Me

as

ure

men

t U

nc

ert

ain

ty,

%

Concentration

Result is quantifiable

Re

sult

is g

reat

er

than

ze

ro,

bu

t n

ot

qu

anti

fiab

le

Re

sult

can

no

t b

e d

isti

ngu

ish

ed

fro

m z

ero

LOD LOQ

Detection & Quantification


Detection Limit

Quantitation Limit

Detection Limits

• 500 MW NGCC Block

• Fuel sulfur < 1ppm

low driving force for SO2

artifact

• EPA Methods 201A/202

• Paired trains, 4 runs

8 samples, 2 train blanks

Blanks & samples similar

• Measured emissions are

below detection &

quantitation limits

Facility permit limit between

LOD and LOQ


NGCC Stack PM2.5: Dilution Results

-0.08

-0.06

-0.04

-0.02

0

0.02

0.04

0.06E

ch

o A

-HI-

R1

Ec

ho

A-H

I-R

2

Ec

ho

A-H

I-R

3

Ec

ho

A-H

I-R

4

Ec

ho

A-L

O-R

1

Ec

ho

A-L

O-R

2

Ec

ho

A-L

O-R

3

Ec

ho

B-H

I-R

1

Ec

ho

B-H

I-R

2

Ec

ho

B-H

I-R

3

Ec

ho

B-H

I-R

4

Ec

ho

B-L

O-R

1

Ec

ho

B-L

O-R

2

Ec

ho

B-L

O-R

3

mg

/ds

cm

Stack-background

AMS

A= DRI sampler

B = Compact sampler

Background PM2.5 (estimated from ambient monitoring

station PM2.5 (AMS), dilution ratio(DR), and dilution air

purifier PM2.5 penetration (PF)) is subtracted from stack

PM2.5

Stack and ambient air PM2.5 concentrations are similar


Summary

• Current AP-42 factors for gas-fired sources

Few sources

High uncertainty

Old, problematic methods

• EPA Methods 201A & 202 (& similar methods) remain

problematic for gas-fired sources

Lack sufficient sensitivity

Blank levels are significant – not due to reagent contamination!

New Method 202 reduces but doesn’t eliminate artifacts

• Dilution methods offer advantages for gas-fired sources

Greater accuracy due to absence of SO2 and VOC artifacts &

greater analytical sensitivity

Resulting PM2.5 emission factors are ~1/10 or lower of those

based on hot filter/cooled impinger methods e.g. AP-42


Summary (cont’d)

• Dilution method evaluation & refinement

Refine & validate test conditions & procedures

Reduce background levels in dilution air & probe recovery

solvents

Reduce organic carbon artifacts

Reduce relative variability of results

• More tests

Document method performance in field

Develop robust emission factors


Questions?

ICEPAG, Newport

Beach, CA April 1-3, 2014

Glenn England

[email protected]

949-798-3643

24

mailto:[email protected]

Fine PM Emission Factors for Gas Turbine Engines 2014/PMEmissions... · Fine PM Emission Factors...

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