SEPA

Emissions & IMlSA§(LMEIMIEM"ir§
Black Carbon
Emissions and Measurement (EM) research activities performed within the National
Risk Management Research Lab (NRMRL) of EPA's Office of Research and Development
(ORD) support measurement and laboratory analysis approaches to accurately
characterize source emissions, and near source concentrations of air pollutants. They
also support integrated Agency research programs (e.g., source to health outcomes)
and the development of databases and inventories that assist Federal, state, and
local air quality managers and industry implement and comply with air pollution
standards. EM research underway in NRMRL supports the Agency's efforts to accurately
characterize, analyze, measure and manage sources of air pollution. This pamphlet
focuses on the EM research that NRMRL researchers conduct related to black carbon
(BC). Black Carbon is a pollutant of concern to EPA due to its potential impact on human
health and climate change. There are extensive uncertainties in emissions of BC from
stationary and mobile sources.
August[2016
Black carbon. Why we should care.
Black Carbon (BC) is a combustion generated pollutant that is extremely effective at directly absorbing solar
radiation. Continued scientific research, spanning a multitude of disciplines including emissions research, is
crucial to understand BC's influence on climate and public health.
Tiny BC particles are emitted from
virtually all fire and combustion
sources. Sometimes referred to as
soot or elemental carbon, these
particles are less than the width of
a single human hair and are thus
invisible to the naked eye. Despite
their tiny stature, they have an
enormous effect on the Earth's
climate and hydrological systems. BC
is second only to carbon dioxide in its
ability to contribute to atmospheric
global warming. BC accelerates snow
pack and glacial melting, which
is expected to have particularly
insidious effects on the water and
terrestrial resources needed for future
generations. BC is a component of
fine particulate matter, which is a
regulated EPA criteria pollutant of
significant public health concern.
With such profound environmental
consequences, a major question is:
How are the science and engineering
communities responding to this
imminent and growing threat? It
turns out there is a group of
"OF COURSE, IT TAKES A
VILLAGE TO ADDRESS A
RESEARCH PROBLEM OF
THIS MAGNITUDE/'
- Michael Hays
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researchers in ORD's NRMRL that are investigating and working with the international science community to better
understand BC emissions. This ORD team, as part of the emissions and measurement research topic, is investing long-
term in BC emissions measurements (EM) research. The team measures BC from a wide variety of emissions sources
using a multitude of advanced methods, technologies, and instrumentation. These researchers maintain and enter
measurements into EPA's SPECIATE database, which, accumulates both domestic and international emissions profile data
for use in both domestic and global dispersion and climate model applications. EPA's measurement data is incorporated
into SPECIATE which feeds into the national and global climate models used to predict local air quality and help predict
the Earth's future weather and climate forcing patterns. Projections appear prominently in the Intergovernmental Panel
on Climate Change (IPCC) reports, which are the fundamental basis for producing international policy on climate change.
Of course, it takes a "village" to address a research problem of this magnitude. Extensive combustion engineering and
field planning is performed at EPA to accurately represent burning processes and properly collect samples for immediate,
on-line BC particle measurements and future laboratory analysis. This EPA team has completed extensive field testing of
BC emissions from a variety of sources including oil and biomass burning to near roadways measurements. The team has
direct access to a vast array of in-house laboratory facilities such as on-site cookstove, vehicle dynamometer, and pilot-
scale coal-burning equipment, providing unique facilities and infrastructure not found anywhere else in the world within
a single organization.
The accuracy of techniques used to measure BC is a question of critical importance. This team of experts also leads the
way in comparing BC measurement techniques. Their efforts continue to expand across the entire ACE research portfolio
and have propagated into other important EPA PM2.5 research with strong collaboration and support from our Program
Office and Regional partners.
Finally, this team continues to collaborate with many of the world's leading scientists and institutions, including Drs.
Tami Bond (MacArthur Fellow; University of Illinois at Urbana-Champaign) and Michael Bergin (Duke University), MIST
and NASA. Together, they push the boundaries of science and help inform leaders and policy makers around the world
and help inform leaders and policy makers around the world.
Story written by Dr. Michael Hays, APPCD
Black Carbon research supported by the office of research and development,
air climate and energy (ACE) Program. Research conducted by scientists in
national risk management research lab (NRMRL).
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WHO&WHAT Exploring the Possibilities of Oxy-Coal Combustion
Outlined below, is the
interdisciplinary group of NRMRL
scientists researching black carbon,
and the sources they study.
NRMRL BC Researchers
Amara Holder
Tiffany Yelverton
Gayle Hagler
Michael Hays
Brian Gullett
Michael Kosusko
Bili Liriak
Jim Jetter
John Kinsey
(,'hun Wai Lee
Key Sources Investigated
Aircraft
Stationary Diesel Engines
Coal Combustion
Wildland and Prescribed Fires
Cookstoves
Mobile Diesel Vehicles
Oxy-fuel combustion
" is a promising method
of carbon capture,
' and differs from
air-fuel combustion.
: in l.Instead of air, fuels are
burned in a mixture of oxygen and
recycled flue gas. By eliminating the
nitrogen in air, the exhaust contains
large concentrations of carbon dioxide
amenable to capture. However, the
high concentrations of carbon dioxide
during combustion can affect a variety
of parameters, including the formation
and behavior of pollutants. As interest
in carbon capture and sequestration
grows, oxy-fuel combustion has be-
come an important area of research.
Bill Linak, CW Lee, and colleagues
are studying the gas and particle
compositions associated with air and
oxy-coal combustion and the effects
of oxygen on char behavior as well as
the formation of BC related submicron
Elemental Carbon (EC) and particle
bound Organic Carbon (OC). Ongoing
testing will provide insights on the
process that produce EC/OC and ways
to minimize their generation. This in-
formation will be critical as regulators
and industry consider this technology
an alternative control for C02 and
other air pollutants.
Above, is a diagram of the entrained-flow
reactor at Research Triangle Park, NC. The
experimental facility is small in size (burning
only 1 gram of coal per minute), but can be
used for air and to simulate one-pass oxy-coal
combustion.
Highlighted BC Measurement Methodologies
V i Jm • ¦
I

There are multiple uncertainties associated
with the impact of BC on human health and the
environment. Since BC cannot be easily defined
or measured, there are many uncertainties
with how to best identify and quantify BC from
emission sources. BC is operationally defined,
that is the BC measured is dependent upon the
measurement technique used. Measurements can vary by 2-3 times from one
method to the next. Moreover, these differences between the measurement
techniques can vary from one combustion source to the next for reasons
that are not entirely clear. Amara Holder has been working to address these
uncertainties by collaborating with multiple EPA colleagues within ORD, OAQPS,
and the Regions to measure and characterize particulate matter emissions from
a variety of combustion sources including gasoline vehicles, diesel generators,
coal combustion, waste gasification, forest fires, and agricultural burning.
Amara is working to create a robust method to measure BC emissions
and concentrations. She has been working with the National Institute of
Standards & Technology (NIST) and the International Bureau of Weights and
Measurements to develop criteria for a BC standard reference material that
can be used to harmonize the many BC measurement methods. These efforts
to reduce a major uncertainty in the BC emissions inventories that feed into
air quality and climate models. Her research will enhance the accuracy of
BC measurement methods which will improve the SPECIATE database, EPA
emissions inventories and future management actions to reduce emissions.
a
Since grad school I've had a passion for
understanding these curious little particles. They
are known by different names but they all refer
to the same surprisingly complicated particle. I
focus on the particles produced from complicated
combustion systems. My goal is to determine
what these particles look like as they are emitted
and age, and how those characteristics impact
the earth's climate. ^
Above (top left), is a photo from a wheat
residue fire in Nez Perce, ID, during August
2013. Above, Amara Holder is taking samples
during a prescribed forest fire at Ft. Jackson,
SC, in October 2011.
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Paving the Way Emissions Characterization for Alternative Fuels
In addition to mobile and ambient sources, a vast array of stationary sources
into the atmosphere. Tiffany Yelverton is exploring alternative fuels and pre-
technologies for reducing emissions from stationary sources.
Retrofitted Stationary Diesel
Generators
The exhaust from diesel engines
is a complex combination of gases
and soot, including compounds
such as PAHs. In 2012, the World
Health Organization classified diesel
engine exhaust as carcinogenic to
humans. For this reason, EPA Office
of Air Quality Planning & Standards
(OAQPS) has been working on
options to regulate diesel engine
emissions and this research enhances
their efforts.
-—5
;» -f
u
Above (top), Tiffany Yelverton is standing
next to the retrofitted 200kW Kholer genset.
Following (bottom), is the blending station at
RIP, which blends coal with raw or torrified
feedstocks prior to testing. The material is
then combusted in the MPCRF.
Since 2013, Tiffany has been
looking at the way emissions
respond to varying power outputs
and aftermarket control devices,
including a diesel oxidation catalyst
and passive and active diesel
particulate filters. Recent efforts
are focused on pre-combustion
techniques, specifically the use of
alternative fuels to reduce PM and
BC emissions. Currently, Tiffany is
testing combustion efficiency and
taking emissions measurements for
a small-scale generator and a large-
scale genset. Fuels being studied
include diesei fuel blended with
natural gas and dimethyl ether.
emit black carbon directly
and post-combustion control
Multipollutant Control Research
Facility (MPCRF)
The MPCRF facility can operate using
a pilot-scale pulverized coal-, natural
gas-, and biomass [located on EPA's
campus in Research Triangle Park,
NC]. The facility has a maximum
firing rate of 4 MMBtu/hr, and
is sized so that researchers can
evaluate combustion conditions and
test, model and scale-up emerging
technologies for commercial and
industrial applications.
Regulations at the state and national
level for coal- and oil-fired power
plants have led to the increased
interest in alternative fuels,
specifically the co-firing of biomass
with coal, in partnership with OAQPS/
SPPD and EPA's Region 4, Tiffany
is investigating the particulate and
gaseous emission characteristics and
optimum blending ratios of feedstocks
with coal. She is measuring many
parameters, including BC emissions.
Raw and torrified feedstocks from
the Southeastern U.S. are being
considered, including sorghum stover,
corn stover, and wood chips.
COOKSTOVES, HUMAN HEALTH & THE ENVIRONMENT
Roughly three billion people around the world rely on open fires and household
cookstoves to heat and prepare meals within their homes. The burning of
solid fuels, such as wood, coal, charcoal, biomass and waste, leads to high
levels of household air pollution and causes a variety of serious human health
and environmental problems. Cookstoves are a large contributor to global BC
emissions.
Jim Jetter has been leading laboratory research efforts on cookstoves including
solar cookers. BC is one of the several pollutants measured during testing,
along with fine particulate matter, carbon monoxide, carbon dioxide, methane,
nitrogen oxides, and total hydrocarbons. Jim is also providing technical support
for the UN Foundation's Global Alliance for Clean Cookstoves and is working
with the International Organization for Standardization to develop global
standards for testing emissions from clean cookstoves.
Above, Jim Jetter, EPA, tests a wood-fueled
forced-draft stove for air pollutant emissions.
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Commercial Aircraft Engines Emissions
Characterization and Worldwide Regulation
For the past 12 years, NRMRL's John Kinsey has participated in
international efforts focused on commercial aviation research.
The International Civil Aviation
Organization (ICAO) is the UN
body responsible for the planning
and development of regulations
and standards for international
aviation. Since the 1970s, the ICAO
has regulated a variety of aircraft
emissions that adversely effect
air quality and human health, in
Fast Fact: One taxi and take-
off for a B747-400 AIRCRAFT
IS EQUIVALENT TO 730 LOADED
TRACTOR TRAILERS TRAVELING
10 MILES WITHIN THE AIRPORT
2004, however, the ICAO requested
additional research be conducted on
non-volatile particulate matter (nvPM)
emissions from commercial aircraft
engines, which mainly consist of BC.
After many years of collaboration with
domestic and international partners,
John and his colleagues generated
an interim test method and standard
that was released in February 2016
for nvPM at the engine exit. The final
document will be released in 2019,
and adoption of the recommended
approach will reduce international
ieveis of this growing source of BC.
Above (top), John Kinsey is standing next to a
large commercial aircraft engine. Below, is an
example of the Air Forces's testing facility and
EPA probes used for am emissions test.
Inside speciate One database, far-reaching impacts
SPECIATE, the EPA's archive for PM
and VOC speciation profiles support
emission inventories, air quality
modeling, and source-receptor
modeling efforts.
These models are the foundation
of air quality and management
decisions, influence national and
local environmental policies and
regulations. In 2013, Mike Kosusko,
the current SPECIATE Workgroup
leader, took over this effort. "SPECIATE
is a key link between researchers who
develop emissions data and the users
of these data.
The SPECIATE 4.4 database houses
over 5,700 profiles, each of which
contain the weight fractions of
chemical species. These are used to
create chemical-specific emission
inventories. For VOCs, they are used
in atmospheric chemistry to support
air quality modeling. Likewise, PM
species weight fractions are specific
to PM size ranges, and are used for
modeling and visibility measurements.
Continued development and upkeep
of the database relies on the SPECIATE
Workgroup, which include expertise
from multiple ORD Laboratories and
Centers and OAR. Data are drawn
from EPA, state agencies, peer-
reviewed literature and other sources.
Currently, modelers use a ratio of EC
and OC to estimate BC for various
sources. EPA researchers are working
to develop a whole new module
of SPECiATE that will include BC
speciation profiles. This is a significant
effort, and will include current work
on measurement methods for BC
Since version 4.4 was released in
February, 2014, 474 profiles have
been added and version 4.5 will be
available to the public in 2016.
Workgroup members: Mike Kosusko, Madeleine
Strum, Rich Cook, Rebecca Matichuk, Cindy
Beeier, Souad Benromdhane, Adam Eisele, Ingrid
George, Mike Hays, Brooke Hemming, Amara
Holder, Sue Kimbrough, Deborah Luecken,
George Pouliot, Havala Pye, Venkatesh Rao,
Heather Simon, Darrell Sonntag, Eben Thoma,
Gail Tonnesen, Catherine Yanca, Tiffany Yelvertori,
Aiexis Zubrow
Below, is Mike Kosusko with a SPECIATE poster
developed by the workgroup in 2011.
EPAs SPECIATE Database and Its Applications
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The Importance
of Analytical
Measurements
Much of the research taking place in-house is supported
by a team of scientists. In addition to conducting his
own research, Michael Hays provides foundational
analytical data for many projects and tasks within
the ACE Research Program and various National
Laboratories. In addition to taking measurements
for EC/OC concentrations, Michael also does GC-MS
and EC-MS analysis to identify and quantify organic
compounds. He has analyzed samples from a variety
of sources, including; stationary diesel generators,
aircraft, light duty and heavy duty on-road vehicles,
near roadway emissions, cookstoves, and wildland,
prescribed and agricultural fires. Among many other
findings, Michael's research has shown that the same
BC that ends up in clouds and snow can also be retained
biologically.

Above (left), is a close up of alveolar
macrophages after being exposed
to diesel exhaust, which contains
significant elemental carbon (Saxena
et, al., Biotechniques 44, p. 799
(2008)) To the right, is a photo of the
carbon analyzer, which measures the
mass of EC per sample analyzed.
For
Additional
Info:
Please feel
free to contact
Carlos Nunez
for questions
or comments
regarding this
pamphlet.
Contact:
Carlos Nunez
919-541-1156
nunez.carlos@epa.gov

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