United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/SR-94/061 May 1994
EPA Project Summary
Field Performance of
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(Method 5G) and has been found to be
accurate.
During this study hydrocarbon emis-
sions were measured for the first time
using this sampler. Collected gas samples
were pumped into Tediar® bags and sent
to VPI for analysis. Both total and non-
methane hydrocarbons were measured.
Problems with sample storage procedures-
resulted in data which are interpreted as
approximate lower estimates for volatile
hydrocarbon emissions.
Summary and Conclusions
The primary thrust of the 1991-92 moni-
toring was quantification of degradation
of emissions control performance. Degra-
dation can be quantified by comparing
results from individual stoves monitored
during different heating seasons, and in
this study there were three stoves (two
catalytic, one noncatalytic) which can be
evaluated this way. The previously moni-
tored Phase I catalytic stoves (CAT05
and CAT07) showed respective emissions
increases of 105% and 189% for PM
emission factors relative to their perfor-
mance two seasons ago. Structural fail-
ure (CAT07) and catalyst degradation
(both stoves) are the probable causes.
One noncatalytic Phase I stove (NCAT09)
was monitored two seasons ago and can
be compared to its previous performance.
When burn rate is taken into account its
performance appears unchanged from the
earlier data.
Based on comparison of 1989-90 cata-
lytic stove data obtained with fresh cata-
lysts, there was evidence of emission deg-
radation (or unusually poor performance
for other reasons) in 67% of the catalytic
stoves monitored. Most of these were
Phase I stoves, and catalyst deterioration
is the suspected cause in most cases.
Two Phase II noncatalytic stoves per-
formed at about the same emission lev-
els observed 2 years ago for Phase I
noncatalytic stoves. The emissions from
noncatalytic stoves are more sensitive to
wood moisture and burn rate than are
catalytic stoves. This sensitivity compli-
cates the comparison of year-to-year data.
After correcting for variations in these
variables, the data showed no evidence
of degradation.
The Phase II catalytic stove was in its
first heating season. Its performance was
approximately the same as that of the
Phase I catalytic stoves of the 1989-90
study, where care was taken to ensure
that stoves and catalysts were in good
condition. However, its PM emission fac-
tor was about twice that of one of the
Phase I stoves when new.
Tediar® bags were used to store gas
samples for later hydrocarbon analysis,
but problems with sample integrity re-
duced the accuracy of the data. The total
hydrocarbon emission factors for cata-
lytic and noncatalytic stoves were esti-
mated at 16.8 and 14.0 g/kg, respec-
tively, using the average of two exponen^
tial sample decay calculations. Based on
some highly preliminary measurements,
these numbers are probably 20% low due
to the adsorption of hydrocarbons by the
desiccant which was part of the sample
train.
The Method 25 analyses of the samples
indicate that approximately 56% of the
hydrocarbons were methane. This corre-
sponds to methane emission factors of
10 and 8 g/kg for catalytic and noncata-
lytic stoves, respectively.
Further monitoring would help to de-
velop a statistically sound database which
can give definitive answers about stove
degradation. This year's work indicates
that catalyst durability is a problem. In-
stove catalyst evaluations and bench tests
would also be of help in future work.
•kv.8. GOVERNMENT PRINTING OFFICE! WM - SSOJM7/IM240
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D. Jaasma, C. Stem, andM. Champion are with Virginia Polytechnic Institute and
State University, Blacksburg, VA 24061-0238.
Robert C.McCrIHl8 is the EPA Project Off tear (see below).
The complete report, entitled "FieldPerformance of Woodbuming Stoves in Crested
Butts During the 1991-1992 Heating Season,"(Order No. PB94-161270; Cost:
$27.00; subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield. VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use $300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/SR-94AJ61
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