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-
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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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