Control of Volatile Organic Compounds Emissions from Manufacturing

esuIts are for a butadiene plant, and butadiene offgas tends to be
1 ean in VOC. Therefore, the test results support the achievability of
98 percent VOC destruction efficiency by a fie1 d incinerator designed
to provide good mixing, even for streams with low VOC concentrations.
. The EPA tests at Union Carbide and Rohm and Haas were for residence
times greater than 0.75 second. However, theoretical calculations
show that greater efficiency would be achieved at 870°C (1600°F) and
0.75 second than at the longer residence times but lower temperatures
represented in these two tests. The data on which the achieveability
of the 98 percent VOC destruction efficiency is based is test data for
similar control systems: thermal incineration at various residence
times and temperatures. If 98 percent VOC reduction can be achieved
at a lower temperature, then according to kinetic theory it can certainly
be achieved at 870°C (1600°F), other conditions being equal.
A control efficiency of 98 percent VOC reduction, or 20 pprn by
compound, whichever is less stringent, has been considered to be the
acheivable control level for a1 1 new inci nerators, considering available
technology, cost and energy use.14 This is based on incinerator operation
at 870°C (1600°F) and on adjustment of the incinerator after start-up.
The 20 pprn (by compound) level was chosen after three different incinerator
outlet VOC concentrations, 10 ppm, 20 ppm, and 30 ppm, were analyzed.
In addition to the incinerator tests cited earlier in this Appendix,
data from over 200 tests by Los Angeles County (L.A.) on various waste
gas incinerators were considered in choosing the 20 pprn level. However,
the usefulness of the L.A. data was limited by three factors: (1) the
incinerators tested are small units designed over a decade ago; (2) the
units were designed, primarily, for use on coating operations; and
(3) the units were designed to meet a regulation requiring only 90 percent
VOC reduct ion.
The 10 ppmv level was judged to be too stringent. Two of the six
non L.A. tests and 65 percent of the L.A. tests fail this criteria.
consideration was given to the fact that many of the units tested were
below 870°C (1600°F) and did not have good mixing. However, due to
the large percent that failed, it is judged that even with higher
temperatures and moderate adjustment, a large number of units would
still not meet the 10 ppmv level.
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