United States
                   Environmental Protection
                   Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
                   Research and Development
EPA/600/S2-88/004  Mar. 1988
&ERA         Project Summary
                   Control Technology Overview
                   Report:  CFC-11   Emissions  from
                   Flexible  Polyurethane  Foam
                   Manufacturing
                   R. W. Farmer and T. P. Nelson
                     An engineering evaluation of techni-
                   cal options to reduce chlorofluorocar-
                   bon (CFC)  emissions  from flexible
                   slabstock and molded polyurethane
                   foam manufacturing plants was per-
                   formed. Included  in the technical
                   options examined were recovery and
                   recycle of CFC-11, alternative chem-
                   icals and processes, and substitute
                   products. Two possible emission con-
                   trol  methods were studied in detail:
                   substitution of methylene chloride  as
                   the auxiliary foam blowing agent and
                   carbon adsorption/recycle of ex-
                   hausted CFC-11 vapors. Promising
                   near-term control options identified for
                   slabstock production were methylene
                   chloride substitution for CFC-11, and
                   establishment of a minimum foam
                   density to reduce the amount of aux-
                   iliary blowing agent used. For molded
                   polyurethane foam production, use of
                   chemical systems which eliminate the
                   need for auxiliary blowing agents
                   appeared to be  a near-term option.
                   Possible longer-term options included
                   carbon adsorption with CFC-11 recov-
                   ery,  development of chemical systems
                   requiring little or no auxiliary blowing
                   agents for slabstock production, and
                   commercialization of new alternative
                   blowing agents.  Each of the longer-
                   term options has in common a need for
                   additional information to adequately
define the optimal implementation
strategy.
  This Project Summary was devel-
oped by EPA's Air and Energy Engi-
neering Research Laboratory, Research
Triangle Park, NC, to announce key
findings of the research project that is
fully documented in a separate report
of the same title (see Project Report
ordering information at back).

Introduction
  Over the past decade, potential deple-
tion of stratospheric ozone through the
action of fully halogenated chlorofluoro-
carbons (CFCs) has been the subject of
extensive study. This phenomenon
involves complicated chemical interac-
tions  that are driven by ultraviolet (UV)
radiation and occur in the upper atmos-
phere. Not only are the  interactions
extremely complex, but direct observa-
tions of them are difficult.
  An  important aspect of the  strato-
spheric ozone depletion issue is the lag
time between emission of CFCs into the
environment and their ultimate arrival in
the upper atmosphere. Since fully hal-
ogenated CFCs are  not readily decom-
posed in the troposphere, they remain
stable for  the  long time required for
transport to the stratosphere. Because of
this extended transport period, effects of
current emissions are not manifested

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until several decades later. Once in the
stratosphere, these compounds can be
acted upon by UV radiation of the proper
wavelengths to release chlorine species
that in turn contribute to destruction of
ozone. Depletion of the earth's protective
layer of stratospheric ozone is predicted
to result in increased biologically  dam-
aging UV radiation's reaching the earth's
surface.
  CFCs are widely used in  several
industries  including flexible  polyure-
thane foam  manufacturing.  In that
industry,  CFC-11  (fluorotrichlorome-
thane) is  used as  a  physical  blowing
agent to reduce  foam density and
increase softness. Another key role of the
CFC-11  is to dissipate heat generated by
the  polyurethane  formation reactions
thereby controlling foam temperature
during formation and curing.
  Emissions of CFC-11 from the flexible
foam manufacturing process are charac-
terized as being prompt;  i.e., all of the
gas  is released  during, or soon after,
foam formation.  It is estimated that
flexible  foam production accounts for
about 30% of the  cumulative CFC-11
which  has been   released  into  the
atmosphere.
  The objective  of this  project was to
evaluate technical options to reduce
emissions of CFC-11 from flexible foam
plants. In this overview study, the depth
of technical evaluation was limited, in
some cases, by the  information available
on each technology. However, two pos-
sible  emission  control  methods were
extensively studied: substitution  of
methylene  chloride for  CFC-11 as an
auxiliary blowing  agent and  carbon
adsorption/recycle of exhausted CFC-11
vapors. Also, an important component of
this  study  was  to summarize recent
innovations in foam technology which
have the potential to reduce or eliminate
CFC-11  use.

Accomplishments/Results
  Control methods  under the heading of
capture/destruction or capture/recycle
techniques include carbon adsorption of
CFC-11, thermal or catalytic incineration,
liquid  absorption, and  direct vapor
condensation.  Pilot tests  have shown
that  carbon adsorption  may be feasible
for CFC-11  control. However, a number
of technical issues have not been satis-
factorily resolved, including fouling of the
carbon bed by isocyanate residue, quality
of recycled CFC, and  disposal  of  used
carbon  and steam  condensate. The
remaining control methods in this cate-
gory presently suffer from either high
cost or a  preponderance of  negative
technical factors which would prevent
their application for flexible foam plants.
  The  cost effectiveness of carbon
adsorption/recycle was found  to  be
highly  variable, depending on the CFC-
11  market price,  recovery  efficiency,
facility size, and required capital invest-
ment. It is  felt that this control method
is more applicable  to slabstock facilities
than molded foam  plants due to poten-
tially more  efficient capture of released
blowing agent from the  slabstock pro-
cess. High capital costs are a substantial
barrier to implementation, because the
competitive nature  of the foam business
makes it difficult for producers to commit
large sums of capital. It would also be
difficult to  offset annualized  operating
costs  through the recovery  credit  for
recycled CFC-11 unless the price of CFC-
11 were to  increase substantially.
  The near-term possibility of methylene
chloride conversion as a CFC-11 control
measure is excellent, since most slab-
stock producers now employ  this  tech-
nology. It is estimated that as much as
70% of all flexible slabstock foam  could
be produced using this alternative blow-
ing agent. Full conversion to methylene
chloride generally requires some expen-
diture for foam reformulation  and plant
modification such as improved ventila-
tion in foam curing areas. These  costs
and the increased difficulty in producing
quality low density,  soft foams with
methylene  chloride are potential imped-
iments for  such conversion.  Therefore,
it is possible that a fraction of the low
density foam market would disappear if
CFC-11 were  no longer available. There
is also a strong preference on the part
of some producers to avoid  methylene
chloride owing to  its own current reg-
ulatory uncertainty.
  Alternative CFCs having ozone deple-
tion potentials lower than CFC-11  are a
promising  long-term  control  method.
Two primary candidates are CFC-123 and
CFC-141 b.  CFC-123 appears to be both
reasonably  safe and technically feasible;
however, CFC-123  production costs are
expected to be higher than for CFC-11
resulting in a bulk sales price roughly two
to four times that of CFC-11. Also, there
is no commercial  scale  production of
CFC-123 in the U.S. at the present time.
Safety considerations are the  major
drawback of CFC-141 b in foam blowing
applications.  Flexible foam  blowing
agents should have lowflammability and
low toxicity,  since  their vapors are
usually present in detectable concentral
tions in the plant environment. Toxico-
logical testing on CFC-141 b has not been
completed; but current reports indicate
that the compound is a "weak mutagen."
In addition, CFC-141 b is reportedly more
flammable than other substitute flexible
foam blowing agents. Chemical produc-
ers have indicated that, without market
incentives to produce  CFC-123 or CFC-
141 b, commercialization is  unlikely and
that even if initiated, from 5 to 7 years
would be required for the chemical to be
commercially available.
  Several recent innovations in the area
of molded polyurethane foam chemical
systems could  ultimately  reduce or
eliminate the need for auxiliary blowing
agents for these foams. In general, these
newer  systems  utilize established HR
(high-resilience) auxiliary  blowing agent
technology, but permit foam production
without CFC-11. These systems employ
either conventional toluene diisocyanate
(TDI) reagents, or a class of isocyanates
referred to as  MDI (methylene diphenyl
isocyanate) compounds, and families of
more reactive polyols.  It is not currently
possible  to  economically achieve U.S.
auto seat  specifications using so-called
"water-blown" MDI-based formulations.
But, TID-based water-blown systems are
available that can produce all currently
used molded foam grades. Only slightly
increased raw material costs are antic-
ipated for these systems.
  New chemical systems have also beer
introduced which would permit produc-
tion of softer slabstock foams without the
use of auxiliary blowing agents, but such
systems have yet to be able to produce
the super-soft, low density foams. These
systems employ more reactive,  anc
generally more expensive, polyols,  and/
or polyol blends.
  Another slabstock process which coulc
reduce the  need for  CFC-11  blowinc
agent has been  developed  in Belgium
and is  currently licensed by Innocherr
S.A. in Switzerland. This process, knowr
as the  "AB  Process," is claimed to b«
applicable to a range of slabstock grades
and some molded foam components, anc
substitutes formic acid for some of th(
water  in  the foam  formulation.  Th<
chemical  reactions  release twice th<
volume of blowing gas as with conven
tional chemistry, but the  additional gas
released is CO. Since CO is a recognize(
toxic gas, extra  monitoring  and safef
precautions  are  necessary. Further
handling of the concentrated formic aci<
involves special ventilation requirement!

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and  materials of  construction.  There
have been no reported full-scale appli-
cations, but some testing of this process
has been carried  out in Europe.
  In  addition to  the technological con-
trols discussed above,  several product
substitutes could be used in place of
polyurethane foam for  certain applica-
tions. Given appropriate market  condi-
tions,  materials  such  as  jute,  cotton
batting, and latex foam could once again
command a portion of the cushioning
market  that  they once  enjoyed prior to
the development  of flexible  polyurethane
foam.  Replacement of polyurethane
foams  by such  materials  would likely
occur only  if CFC-11  and methylene
chloride emissions were both regulated,
thus increasing  the  costs of the  low
density polyurethane foam  grades.
R. W. Farmer and T. P. Nelson are with Radian Corp., Austin, TX 78720.
N. Dean Smith is the EPA Project Officer (see below).
The complete report, entitled "Control Technology Overview Report: CHC-11
  Emissions from Flexible Polyurethane Foam Manufacturing," (Order No. PB
  88-160 387/AS; Cost: $25 95, 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

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United States
Environmental Protection
Agency
                                      Center for Environmental Research
                                      Information
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