EPA/600/A-98/019
The U. S, EPA Biomass Fuel Analytical Laboratory
Evelyn Baskin and Chun Wai Lee
U. S. Environmental Protection Agency, NRMRL, MD-63, RTP, NC 27711
(919) 541-2429; Pax: (919) 541-7885
David F. Natschke
Acurex Environmental Corporation, 4915 Prospectus Drive, Durham, NC 27713
ABSTRACT
This paper describes the U.S. EPA's biomass fuel analytical laboratory at the EPA's
Environmental Research Center in Research Triangle Park, NC. There is increasing
interest in utilizing biomass based fuels in thermal energy systems as an effective
means for global warming remediation. However, information on biomass combustion
emissions, which is needed in order to assess the potential environmental impacts of
biomass fuel combustion, is insufficient. To fill this need the laboratory is examining
biomass fuels and their potential of forming in products of incomplete combustion
(PICs) under different thermal conditions. The objectives are to evaluate the kinetics
of combustion and emission characteristics (e.g., structure and composition) of
representative samples of relevant types of biomass fuels through studying 1) the local
pyrolysis and combustion processes and products, and 2) the overall degradation rate
as influenced by heat transmission.
Biomass fuel samples will be examined by thermogravimetric analysis with an on-line
Fourier transform infrared spectrometer (TGA-FTIR). EPA built a prototype TGA
which is capable of handling a 100 g sample with 1 pg resolution for this laboratory-
This instrument is capable of heating the sample to 1200°C. Samples can be pyrolyzed
and combusted sequentially by automated gas switching. The effluent- gases are
passed to the heated gas cell of a Mattson FTIR for on-line identification and
quantification of hydrocarbons, carbon monoxide, carbon dioxide, sulfur dioxide, and
water. Summa canister samples are collected for analysis by gas
chromatography/mass spectroscopy (GC/MS). Hydrogen is determined by gas
chromatography/thermoconductivity detector (GC/TCD). Particulates are determined
from the residue on the TGA sample pan and a filter sample collected between the
TGA and FTIR and analysis gravimetrically by atomic absorption spectroscopy (AAS
or inductively coupled argon plasm).
KEYWORDS
Biomass, TGA/FTIR, GC/MS, combustion, pyrolysis
BACKGROUND
Steam turbine power plants fired with fossil fuels are utilized to generate
approximately 80 % of the electrical power worldwide. In an effort to reduce

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greenhouse gas emissions in accordance with the Federal Climate Change Action Plan,
other fuel sources are being investigated. Data on the emissions generated by the
pyrolysis or combustion of non-woody feedstocks (e.g., herbaceous, agricultural waste)
are not well documented or have not been demonstrated. Emissions data from woody
feedstocks are more prevalent, but trace organic compounds emissions data are
deficient. Characterization of a comprehensive range of biomass fuels can assist in
designing feed and combustion systems, determining plant and component efficiency,
determining life cycle costs, and determining environmental impacts. Biomass fuels
can be utilized to produce various end products including those generated from:
microbial and enzymatic processes to produce methane and ethanol; thermochemical
processes (pyrolysis, gasification, direct liquefaction) to produce methanol, synthesis
gas, or pyrolysis oils; and direct combustion for steam and electricity generation
(Sanderson et al., 1996). The EPA's (Environmental Protection Agency's) APPCD (Air
Pollution Prevention and Control Division) of the NRMRL (National Risk Management
Research Laboratory) has undertaken the task to characterize representative samples
of various types of biomass fuels which are carbon dioxide (C02) neutral. This
evaluation couples environmental concerns and equipment performance utilizing
biomass fuels.
The characterization will be done using thermogram met ri c analysis (TGA) coupled
with Fourier transform infrared (FTIR) spectroscopy for detection of evolved gases.
Coupling these devices elucidates extensive information concerning the structure,
composition, and combustion and pyrolysis kinetics of fuels. The FTIR provides
constant monitoring (during pyrolysis and other reactions) of the IR spectra of evolving
gases, as well as a quantitative analysis of gases. Utilizing the TGA/FTIR enables
identification of the evolved gases that correlate to the specific TGA weight loss. The
literature has shown that the TGA/FTIR combination provides more detailed and
accurate data than using a TGA alone. Laboratory capabilities have been designed
and planned to encompass a TGA/FTIR, gas chromatograph/thermal conductivity
detector (GC/TCD), adiabatic bomb calorimeter, and access to a GC/mass spectrometer
(MS) and open burning facility. All gases will be analyzed using the TGA-FTIR,
GC/TCD, and GC-MS. Figure 2 illustrates the laboratory layout.
BIOMASS MATERIAL AND FUEL COMBUSTION EMISSIONS
Biomass and biomass fuels are from a variety of sources and fuel types, as seen in Fig.
1. Fuels are selected based on their availability for use as a sustainable feedstock for
biomass power generation. Fuel viability will be region specific , since the abundance
of a fuel source in one area of the country does not guarantee its availability in another
(e.g., various agricultural wastes, different tree species). Biomass tested for non-power
generation fuel applications is selected based on its environmental impact when
burned (e. g., forest management, waste disposal).
Recent data reveal that gaseous methyl bromide (CH3Br) is produced by biomass open
burning and may account for 30% of the CH3Br in the atmosphere (Cicerone 1994).
CH3Br has been shown to be released during the flaming and the smoldering phases of
burning. Mano and Andreae (1994) measured CHsBr emission from wildfires in the
savannas, chaparrals, boreal forests, and laboratory biomass combustion experiments.
2

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Fig. 1, Biomass material and fuel sources and variety.
From their work they estimated the global emission of CH3Br to range from 10 to 50
Gg per year. The CH3Br ozone depletion potential (ODP) is 1.9 for a time horizon of
30 yrs (UNEP 1992). CH3Br is listed in the Clean Air Act as a Class I ozone-depleting
substance, and its industrial production is scheduled to be phased out by the year
2001. CHgBr is more reactive than the perhalogenated halon compounds; therefore,
only a few percent of it emitted at the Earth's surface reaches the stratosphere.
The combustion of biomass material releases significant quantities of nitrous oxide
(N20), nitric oxide (NO), and ammonia (NH3) to the atmosphere. Experimental
quantification of the type and amount of nitrogen gases returned to the atmosphere
during burning estimates 20 to 36 Tg N per year. N20 and NO are fundamental gases
involved in global climate change. NO contributes to the production of ozone (03) in
the troposphere; production of nitric acid (HNOs), a component in acidic precipitation;
and the chemistry of hydroxy 1 radical (OH), a chemical agent in the troposphere. NzO
is a greenhouse gas with a global warming potential 200 times that of C02. Major
sources of N20 are uncertain, and recent discoveries indicate that at least 30% of its
global production is not known (Levine et al., 1997).
Studies of biomass burning from a global warming perspective recently have been
published more frequently (Crutzen et o/.1985, Crutzen and Andreae 1990, Houghton
1990); however, most of these studies are narrowly focused on estimating global total
emissions or emissions ratios relative to C02; emissions of other volatile organic
species such as methyl bromide have not been investigated. The EPA has compiled
emission factors for forest fires for total particulate, carbon monoxide (CO), total
hydrocarbons, and nitrogen oxides (NO,) (USEPA, 1985). A detailed study on
measuring emission factors for C02, CO, total hydrocarbons, formaldehyde, total
organic acids, NO,, total particulate, and nine polycyclic aromatic hydrocarbons
(PAHs) from the open burning of "landscape refuse such as lawn clippings, leaves and ~
3

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tree branches" found that total particulate and total hydrocarbons are the major
emissions (Gerstle and Kemnitz 1967), Another study based on airborne
measurements of open burning of logging debris also found that total particulate is
the major emission from biomass open burning (Radke et al.. 1978).
As emissions from open burning of a wide variety of combustible materials became
increasingly a major air quality problem, the EPA conducted a series of emission tests
at its Open Burning Simulation Facility also at Research Triangle Park. The facility
was designed to provide open burning conditions similar to those in the field and is
equipped with sampling equipment for detailed emission characterization from the
simulated open burning tests. Tests have been performed to characterize emissions
from combustion of agricultural plastic (Linak and Ryan 1989), used tires (Ryan 1989),
automobile recycling fluff (Ryan and Lutes 1993), and fiberglass (Lutes and Ryan
1993) under simulated open burning conditions. It was found that the emission data
generated from the simulated open burning experiments conducted at the facility
correlated remarkably well with those collected from real fires. The facility has been
found to be a valuable tool for systematic study of open burning on a wide variety of
combustible materials.
TEST METHODS AND FACILITIES
Biomass Fuel Analytical Laboratory Test Methods
Biomass fuels used in previously published literature will be tested to validate the
testing method and results using a thermogravimetric analysis/ Fourier transform
infrared spectroscope (TGA/FTIR) and gas chromatography/mass spectroscope
(GC/MS) that will be located in the biomass fuel analytical and combustion
laboratories. Following substantiation of the method, gas plume and solid biomass
fuel samples collected from prescribed fires at experimental forest sites will be tested.
A testing protocol will be developed for each type of biomass fuel tested, and several
tests of each fuel type will be performed. Chemical libraries containing suspected gas
emissions from thermal degradation will be used in gas identification. Various
biomass samples up to 100 g will be burned under various controlled temperatures and
specified air supply conditions to establish an extensive characterization of the fuels in
the laboratory. Thermal degradation will be evaluated using oxygen and nitrogen as
combustion gases. Utilizing nitrogen will assist in studying pyrolysis, while use of
oxygen will aid in studying material combustion. Argon will be used as a purge gas for
evaluation of NO, missions from thermal degradation of the material. The TGA will
provide kinetic data of the fuel. The kinetic properties will be evaluated under various
temperature heating rates and temperature-hold settings, Allowing the evolving gases
to flow into the FTIR from the TGA will link the kinetics and emissions properties of
the biomass materials. Materials found to emit CH3Br and methyl chloride (CHaCl)
will be further tested in an open burning facility which can better simulate actual
conditions to validate laboratory testing and determine how near-actual conditions
affect emissions.
4
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/tga\
/ MS \
V,
/dCftCD\
~
Fig. 2. Biomass facilities (zigzag lines indicate that equipment is located in
separate laboratories, GC/MS is not realtime analysis)
Open Burning Test Methods
Experiments will be performed to measure CH3Br and CH3C1 from burning biomass
fuels in the open burning facility which simulates the actual conditions of open field
burning. Emphasis will be placed on identifying the air supply and temperature
conditions under which CH3Br and CHaCl emissions will likely occur during open
burning The open burning tests of this project are designed to collect and
qualitatively and quantitatively characterize CH3Br and other volatile organic
emissions resulting from the simulated open combustion of biomass materials. Small
quantities (9 to 21 lb, 4 to 10 kg) of biomass materials are combusted in several
charges within a test facility specifically designed to simulate open-combustion
conditions, A portion of the combustion effluent is diverted to an adjacent sampling
facility through an induced draft duct. Samples are collected from this stream using
the volatile organic sampling train (VOST). A portion of the sample from the induced
draft duct is also analyzed by a series of continuous emission monitors (OEMs) for C02,
CO, NO, oxygen (02), and total hydrocarbons (THCs). Data provided by the CEM
measurements can indicate combustion conditions. The organic constituents of the
VOST samples are analyzed both qualitatively and quantitatively using gas GC/MS.
Measured, organic species concentrations are related to dilution air volumes and the
measured net mass of biomass combusted to derive emission rates.
Biomass Fuel Analytical Laboratory Facility
The biomass fuel analytical laboratory is a 440 ft2 (40.9 m2) space located at EPA's
Environmental Research Center in Research Triangle Park, NC. The laboratory is	
5

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equipped with a TGA/FTIR system. The Galaxy 3020 FTIR and TGA interface are
made by Mattson Instruments, Inc., and the TGA is made by Abbess Instruments, Inc.
The Galaxy 3020 is a single-beam spectrometer. The spectral range of the FTIR is
4000 - 400 wavenumbers (cm1) with a maximum resolution of 2 cm"1. The system has
nine scan velocities and a KBr beamsplitter. The system uses a dry air or nitrogen
purge gas. The MCT (mercury cadmium telluride) detectors are cooled by liquid
nitrogen. The TGA interface/heated transfer line is maintained at 300°C. The TGA
accepts solid biomass fuel samples up to 100 g. The furnace achieves a maximum of
1200°C and is able to increase the gas temperature near the sample from 100°C to
1200°C at a rate of lOOOC/min. The TGA utilizes inert gas or combustion air as its
purge gas. The TGA's computer controls the its temperature and collects mass data.
The TGA and FTIR share a printer and plotter which generate data tables and plots
from physical and chemical results. Each system has a 486 CPU data acquisition
system. Additional gas analyses can be performed by extracting a sample from gases
exiting the FTIR. This gas will be injected into a Hewlett Packard 6890E GC or a
GC/MS for farther analyses. See Fig. 2 for laboratory layout and Fig. 3 for the data
collection and analysis process.
Open Burning Facility
y
The Open Burning Simulation Facility, located on the grounds of EPA's
Environmental Research Center, in Research Triangle Park. NC, is used to simulate
the open burning processes of a variety of combustible materials and study the
resulting emissions. Examples of these materials have included tires, non-metallic
automobile shredder residue, Chinese coals, fiberglass materials, household waste, and
land clearing debris. Open combustion is simulated by burning the test material in a
burn hut over a period of hours while maintaining a high dilution rate, thus allowing
approximately two complete air exchanges per minute. The burn hut is an 8- by 8- by
8-ft (2.4- by 2.4- by 2.4- m) outbuilding modified for open-combustion experiments.
The building has been fitted with a conditioned, dilution air handling
system capable of delivering nominally 1,200 ft3/min (34.0 m3/min). This flow rate is
sufficient to maintain a positive pressure within the facility. Thus, it could be
assumed that the outflow rate from this facility is roughly equal to this inflow rate.
The biomass material is combusted in a 16- by 16- by 16-in (0.4- by 0.4- by 0.4-m)
stainless steel burn pit insulated with a fire brick enclosure and mounted on a
platform scale to continuously monitor weight loss due to combustion. A deflector
shield is located 4 ft (1.2 m) over the pit to deflect flames, protect the ceiling, and
enhance ambient mixing. The sample transport duct, an 8-in (203-mm) O.D. stainless
steel pipe, is located directly over the rear corner of the burn pit. This duct transports
a representative portion of the gaseous, sample to the sampling shed located adjacent
to the burn hut. Temperatures are monitored in a variety of locations within the burn
pit, sample duct, and air input ducts by means of thermocouples.
The sample shed contains the associated sampling equipment including the VOST
system and the particulate removal system for the CEMs. The digital readout for the
platform scale is monitored remotely in the sample shed. All gaseous samples are
extracted from a sampling manifold within the duct located in the sample shed. The
sample stream xs pulled from the burn hut into the sample shed under vacuurn by an
6

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Fig. 3. Flow process of biomass fuel data collection and analysis.
induced draft (ID) fan downstream of the sample manifold. Methyl bromide and other
volatile organics are collected through the VOST sampling train connected to the
sample manifold. A heated, particulate-free sample is also obtained from the sample
manifold and routed through a filter to individual CEMs for continuous measurement.
Quality Assurance
These studies will be performed in accordance with the approved laboratory and field
testing quality assurance management plan. An EPA quality assurance project plan
(QAPP) will be submitted prior to data collection. The QAPP will address, for
instance, GC and FTIR response which will be calibrated to National Institute of
Standards and Technology (NIST) reference gases. Replication and measurement
variability will also be discussed in the QAPP.
EXPECTED RESULTS AND CONCLUSIONS
The EPA's state-of-the-art biomass fuel analytical laboratory will provide high quality
fundamental combustion and pyrolysis analyses on a wide variety of biomass
materials. The laboratory will also provide data from the thermal degradation of these
materials that will reveal the environmental impact of utilizing them in various
applications. Experimental results anticipated include detailed characterization of the
pyrolysis and combustion of a wide variety of biomass materials at various TGA
temperature ramp rates and hold settings. Coupled with these data will be the
identification and quantification of gas emissions including trace organic compounds
(e. g., methyl bromide and methyl chloride). Also, this research will supply data that
will facilitate quantification of NOx emissions from biomass burning. Results from this
laboratory will be useful for the scientific community, the government, and industry.
7

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REFERENCES
Cicerone, R. J. (1994). Fires, Atmospheric Chemistry, and the Ozone Layer.
Science, 263, 1243 -1244.
Crutzen, P. J,, A. C. Delany, J. Greenberg, P. Haagenson, L. Heidt. R. Lufb, W.
Pollock, W. Seiler, A. Wartburg, and P. Zimmerman (1985). Tropospheric Chemical
Composition Measurements in Brazil during the Dry Season. J. of Atmospheric
Chem., 2, 233 - 256.
Crutzen, P. J. and M. O. Andreae (1990). Biomass Burning in the Tropics: Impact
on Atmospheric Chemistry and Biochemical Cycles. Science, 250. 1669-1678.
Gerstle, R. W. and D. A. Kemnitz (1967). Atmospheric Emissions from Open
Burning. JAPCA, 17(5). 324 - 327.
Houghton, R. A. (1990). TCie Global Effects of Tropical Deforestation.
Environ. Sci. Technol., 24(4). 414 - 422.
Linak, W. P. and J. V. Ryan (1989).Chemical and Biological Characterization of
Products of Incomplete Combustion from the Simulated Field Burning of
Agricultural Plastic. JAPCA, 39(6). 836 - 846.
Levine, J. S., W. R. Cofer III, D. R. Cahoon, E. L. Winstead, D. I. Sebacher. M.
C. Scholes, D. A. B. Parsons, and R. J. Scholes (1997). Biomass Burning, Biogenic
Soil Emissions, and the Global Nitrogen Budget. Biomass Burning and Global
Change, 1, 370 - 380.
Lutes, C. C. and J. V. Ryan (1993). Characterization of Air Emissions from the
Simulated Open Combustion of Fiberglass Materials, EPA/600/R-93-239 (NTIS PB
94-136231).
Mano, S. and M. O. Andreae (1994). Emission of Methyl Bromide
from Biomass Burning. Science, 263.1255 - 1256.
Radke, L. F. et al. (1978). Airborne Studies of Particles and Gases from Forest
Fires. JAPCA, 28(1). 30 - 34.
Ryan, J. V. (1989). Characterization of Emissions from the Simulated Open
Burning of Scrap Tires. EPA/600/2-89/054 (NTIS PB90-126004).
Ryan, J. V. and C. C. Lutes (1993) Characterization of Emissions from the
Simulated Open-Burning of Non-metallic Automobile Shredder Residue. EPA/600/R-
93-044 (NTIS PB93-172914).
Sanderson, M. A., F. Agblevor, M. Collins, and D. K. Johnson (1996),
Compositional Analysis of Biomass Feedstocks by Near Infrared Reflectance
Spectroscopy. Biomass and Bioenergy, 11(5). 365 - 370.
United Nations Environment Programme (UNEP) (1992). Methyl Bromide:
Its Atmospheric Science, Technology, and Economics. Montreal Protocol Assessment
Supplement.
USEPA Office of Air Quality Planning and Standards (1985). Compilation of Air
Pollutant Emission Factors. AP-42,4th edition, Vol. 1 (GPO 055-000-00251-7).
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INEMRL-RTP-P-200 llllllllllllllllllillll 1
EPA/600/A-98/019 2
3"\ PB98-14Q312 j
A, title and subtitle
The U.S. EPA Biomass Fuel Analytical Laboratory
S. REPORT DATS
6. PERFORMING ORGANIZATION CODE
7. authors Evelyn Baskin and Chun Wai Lee (EPA), and
David F. Natschke (Acurex)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Acurex Environmental Corporation
4915 Prospectus Drive
Durham, North Carolina 27713
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-D4-0005
13. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air Pollution Prevention and Control Division
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Published paper; 1-4/97
14. SPONSORING AGENCY CODE
EPA/600/13
".supplementary notes ^PPCE) project officer is Evelyn B as kin, MD-63, 919/541-2429,
For presentation at Third Annual Biomass Conference of the Americas. Quebec,
Canada, 8/24-29/97.
16.abstractjjle paper describes the U.S. EPA's biomass fuel analytical laboratory at
its Environmental Research Center in Research Triangle Park, NC. There is increa-
sing interest in utilizing biomass-based fuels in thermal energy systems as an effec-
tive means for global warming remediation. However, information on biomass com-
bustion emissions, which is needed to assess the potential environmental impacts of
biomass fuel combustion, is insufficient. To fill this need, the laboratory is examin-
ing biomass fuels and the variation in products of incomplete combustion (PICs) with
combustion conditions. The objectives are to evaluate the kinetics of combustion and
emission characteristics (e. g., structure and composition) of representative sam-
ples of relevant types of biomass fuels by studying 1) the local pyrolysis and combus-
tion processes and products, and 2) the overall degradation rate as influenced by heat
transmission. Biomass fuel samples will be examined by thermogravimetric analysis
with an on-line Fourier transform infrared spectrometer (TGA-FTIR). EPA has
built a prototype TGA, capable of handling a 100 g sample with 1 microgram re-
solution for this laboratory. This instrument is capable of heating the sample to 1200
C. Samples can be pyrolyzed and combusted sequentially by automated gas switching.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDEO TERMS
c. COSATl Field/Group
Pollution Greenhouse Effect
Biomass Thermogravimetry
Combustion Fourier Transforma-
Pyrolysis tion
Fuels Spectrometry
Analyzing Gas Chromatography
Pollution Control
Stationary Sources
Global Warming
Thermoconductivity
Atomic Absorption
13	B 14 A
08A, 06C
2 IB
07D 12 A
2 ID
14	B
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
20-SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2223-1 <9-73)
REPRODUCED BY; Nlijafc.
US Department o! Cammerc*
Sprlnflfitldi Virginia 221 SI

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