Control of Volatile Organic Compounds Emissions from Manufacturing

control devices, such as thermal and catalytic incinerators or boil ers
and process heaters, can achieve 98 percent VOC destruction efficiency"
required for polypropylene and high density polyethylene 1 iquid-phase
processes. Therefore, the current CTG has been revised so that alternate
control techniques are clearly defined as acceptable RACT if they
achieve the appropriate emission reductions or 1 imits.
'In addition, this final CTG document has been revised so that
a1 ternative control techniques are discussed, cost estimates are
presented for not only thermal incinerators but also flares for PP and
HDPE, and condensers for PS.
C.3 STRINGENCY OF RACT
Summary of Comments
TCC, CMA, and Gulf questioned the ability of thermal incinerators
to achieve 98 percent VOC destruction on a continuous or average basis
under normal and realistic design and operating practice. Monsanto
specifically questioned the extrapolation of its incinerator test data
from acryloni trile to polymer production, while Gul f questioned the
applicability of test data from the CTG for air oxidation processes.
TCC agreed that 98 percent VOC reduction was achievable in all new,
well designed and well operated incinerators, but be1 ieved RACT should
be based upon "demonstrated levels in equipment that operates pretty
much as designed without elaborate post installation modifications to
fine-tune it to maximum (efficiency) levels." TCC also felt that
thermal incinerator efficiency should be discounted to more realistic
levels since flare efficiency was discounted. CMA was of the opinion
that 98 percent reduction was more appropriate for LAER than RACT and
was not consistent with other VOC emission limits under development.
Response
The questions regarding the stringency of RACT and the capability
of thermal incinerators to realistically achieve 98 percent VOC destruction
probably have become superfluous since flares have been accepted as
capable of achieving equivalent destruction and they have lower cost
so that flares are likely to be used to satisfy RACT, where needed.
However, the state of the art supports that new incinerators can
achieve 98 percent reduction if properly designed and operated, as TCC