United States
Environmental Protection
Agency
Research and Development
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
EPA/600/S2-90/057 Mar. 1992
EPA Project Summary
Solvent Emission Reduction
Study at Newark AFB, Ohio
Jacqueline Ayer and C.D. Wolbach
The objective of this effort was to
collect baseline Freon emissions data,
and subsequently recommend poten-
tial emission control alternatives to mini-
mize Freon emissions that result from
routine maintenance and repair opera-
tions conducted at Newark AFB, Ohio.
This Project Summary was devel-
oped by EPA's Air and Energy Engi-
neering Research Laboratory, Research
Triangle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Introduction
Newark AFB, Ohio, uses a number of
solvents to clean and maintain electronic
guidance devices. The solvent most often
used in this application is 1,1,2-trichloro-
1,2,2-trif luoroethane, commonly known by
the DuPonf Company trademark Freon
113™ (hereafter referred to as Freon}. New-
ark AFB purchases large quantities of Freon
(nearly 600,000 Ib annually), and in previ-
ous years, lost nearly all of. it (555,000 Ib)
as unrecovered Freon vapor.* Freon is
* This quantity was derived in an earlier solvent inven-
tory study performed to identify significant Freon emis-
sion sources at Newark AFB. This study took into
consideration the quantity of Freon purchased in the
1-year period studied, the change in the quantity of
Freon stored onsite, and the quantity shipped offsite
as a hazardous waste and sold to a solvent reclama-
tion facility. The quantity of Freon lost due to evapora-
tion (555,000 Ib [252,272 kg]) was only slightly less
than the quantity purchased (596,000 Ib [270,909
kg]).
one of a general class of chemicals known
as chlorofluorocarbons (CFCs). Scientific
evidence strongly suggests that CFG emis-
sions are responsible for the depletion of
the protective ozone layer surrounding
Earth's atmosphere. For this reason, the
U.S. Air Force must reduce and eventually
eliminate CFC emissions from Air Force
facilities.
Several steps have been taken to re-
duce the quantity of Freon emitted, from
the more than 100 emission point sources
at Newark AFB. For example, solvent va-
pors emitted from more than half of the
point sources at the facility are recovered
with limited success by the use of two
carbon adsorption (CA) systems. The per-
formance of the recovery system in the
past has been marginal at best, primarily
due to an inadequate regeneration sched-
ule.
In addition to the CA systems, continu-
ously operated distillation equipment is
used to purify recovered liquid Freon for
reuse. However, military specifications re-
quire that most processes use only
ultrapure solvent, so only Freon that is not
significantly contaminated may be recycled.
The remainder is sold to an offsite waste
handling .facility.
Scope
To develop methods of reducing Freon
emissions from the cleaning and mainte-
nance activities at Newark AFB, baseline
emissions testing at key sites was per-
formed. The data collected were evaluated
to identify primary emission sources, and
ventilation system inefficiencies. The re-
sults of this evaluation were used to de-
Printedon Recycled Paper
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velop several Freon emission reduction
strategies.
Approach
This project was conducted in two steps.
Step 1 involved a source identification study
and a Freon emissions survey. Such engi-
neering parameters as temperature, pres-
sure, flow rates, and Freon concentrations
were measured. This information was re-
quired to accurately determine the Freon
emissions profile of Newark AFB, as well
as to facilitate the identification of various
emission reduction strategies. Step 2 con-
sisted of reducing the data collected in
Step 1 and developing and evaluating a
number of Freon emission control strate-
gies.
Test Description
Three principal measurements were
performed during this test series: (1) mea-
surement of airflow rates through exhaust
ducts, (2) measurement of the linear flow
rate at the front faces and access ports of
process booths connected to the CA sys-
tems, and (3) measurement to determine
Freon concentration variations in the duct
over an extended period of time. At two
test sites (CA 3 and 4), a fourth measure-
ment was performed to determine the 1,11,1 -
trichloroethane (TCA) concentration
variations. TCA is occasionally used in the
process booths connected to the CA sys-
tems.
Results
The emission test results obtained were
in good agreement with results obtained
from the Freon emission inventory study
performed a month prior to testing. Thus,
the confidence level in the data collected is
high. Several Freon emission reduction
strategies were identified based on these
results which, if implemented, will result in
a Freon emission reduction of more than
60%.
Conclusions
From the. data collected in this test
effort and the engineering evaluation re-
sults, the following conclusions can be
drawn:
The quantity of Freon emitted from
the Peacekeeper, Refurbishing, and
Clean Room 12 areas total more than
54,432 kg (120,000 Ib) per year; thus
emissions from these areas should
be targeted for major reduction.
Emission sources not vented from
process areas should be placed in
hoods vented to a solvent vapor re-
covery system.
Current CA system regeneration
schedules are inadequate.
• Test results are in general agree-
ment with those obtained from the
Newark solvent chemical inventory
survey performed prior to testing.
Implementing the recommendations
made in this report should result in
an emissions reduction of more than
113,400 kg (250,000 Ib) annually.
Recommendations
Recommendations made are of two
types: those that can be adopted almost
immediately and those that will take some
time to implement. These short- and me-
dium-term recommendations are presented
separately. The medium-term recommen-
dations are:
Significant emissions from the Peace-
keeper area should.be eliminated by
connecting the source exhaust ducts
from the Peacekeeper area to the
CA 3/4 network.
Under current operations, CA 4 is
significantly underutilized compared
to CA 3, which is operating at near
maximum capacity. Newark AFB
should either1 connect the Peace-
keeper area exhaust ducts to CA 4,
or offload most of the CA 3 sources
to CA 4, and connect the Peace-
keeper exhaust ducts to CA 3. •
Some flow balancing will be required
after the sources are integrated to
ensure that sufficient ventilation air
passes through each source.
A separate solvent vapor recovery
system should be installed to control
emissions from the Refurbishing and
Clean Room 12 areas.
The emission sources that are cur-
rently uncontrolled (i.e., degreasers
and ultrasonic cleaners), should be
vented to a vapor recovery system.
However, the cumulative contribution
from these sources could have a sig-
nificant impact on the recovery sys-
tem operation. Thus, after they are
vented, the Freon emissions from
these sources should be quantified
to assess their potential impact on
vapor recovery system operations.
A means of determining Freon evapo-
ration rates in the significant emis-
sion source areas (i.e., Peacekeeper,
Refurbishing/Clean Room 12, Clean
Room 3) should be installed. In this
way, the impacts of changes in oper-
ating areas on CA bed performance
can be determined.
The short-term recommendations are:
Feedback control loops should be
installed at the exits of both CA sys-
tems to eliminate the emission of
Freon vapor into the environment due
to CA bed breakthrough.
CA 3 and 4 should be converted
from split-flow to single-bed opera-
tion.
Until feedback control loops are in-
stalled in the CA bed effluents, new
regeneration schedules for CA 3 and
4 should be adopted.
Freon emissions from CA 4 due to
the intermittent duty cycle of the point
sources vented in CA 4 should be
significantly decreased. The most
cost-effective means of controlling
these emissions is to turn off the 10-
hp (7.5 kW) exhaust fan upstream of
the bed during process downtime (i.e.,
weekends, and second and third
shifts). This will reduce the possibility
of solvent migration through the bed
and subsequent breakthrough.
•&U.S. GOVERNMENT PRINTING OFFICE: 1992 - 648-080/4017S
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J. Ayerand C.D. Wolbach are with Acurex Corp., Mountain View, CA 94039.,
Charles H. Darvin is the EPA Project Officer, (see below).
The complete report, entitled "Solvent Emission Reduction Study at Newark AFB, Ohio,"
(Order No. ADA 242-091/AS; Cost: $26.00, 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
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EPA/600/S2-90/057
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