Preliminary Environmental Assessment Of Afterburner Combustion Systems


 United States
 Environmental Protection
 Agency
 Industrial Environmental Research
 Laboratory
 Research Triangle Park NC 27711
 Research and Development
 EPA-600/S7-80-153  Aug 1981
 Project Summary
 Preliminary  Environmental
 Assessment  of Afterburner
 Combustion  Systems

 Richard E. Barrett and Phillip R. Sticksel
  The report gives results of an envi-
ronmental assessment of afterburner
control systems (fume incinerators). It
consisted of a review of available data
and literature, and the planning of a
subsequent experimental program,
intended to  consist of laboratory
and/or field emission measurements
to provide data not presently available.
The report describes the use of existing
data to estimate the potential national
usage of afterburners based on emis-
sions. It also reports on an evaluation
of field test data from the files of one
local air pollution control agency.
Results of the analyses show that the
average efficiency of in-service after-
burners may be significantly less than
that reported in much of the literature.
Although a lower afterburner efficiency
is likely to have little impact on national
organic nonmethane emissions, it
may have marked impact in  local
areas.
  This Project Summary was devel-
oped by EPA's Industrial Environmen-
tal 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
  Organic emissions are of concern
because of their participation in  reac-
tions leading to the production of oxi-
dants, and because (in certain locales)
further reactions produce aerosols as
well as irritating smogs. One type of
device that-can be used to control
hydrocarbon or organic emissions from
some stationary sources is the after-
burner, or fume incinerator.
  Afterburners can be applied to some
but not all organic emission sources.
Generally they can be applied to organic
emission sources having a well defined
and contained emission  stream; e.g.,
chemical, metallurgical, surface coating,
and agricultural processes. They cannot
be applied readily to sources having
scattered and uncontained organic
emissions; e.g., burning  landfills and
coal refuse piles, pipe leaks, and uncon-
tained vents.
  With such widespread  use of after-
burners, it is important to national and
local air quality efforts to understand
just how successfully afterburners
control emissions. Unfortunately, the
overall performance of afterburners has
frequently been based on limited re-
search or on tests of new or well-tuned
units. These tests measure afterburner
performance of units operating at peak
efficiency. Consequently, efficiency
values above 90 or 95 percent (some-
times as high as 99 percent) are usually
reported. However, there  remains the
strong suspicion that performance of
typical in-service afterburners is not as
good as that reported in the idealized
tests. Because afterburners are not
income-producers, it is suspected that
their operation and  maintenance may
receive less than adequate attention.

-------
  This program considers the extent of
application of afterburners, and reports
on afterburner  performance based on
results of a limited number of after-
burner emission tests conducted by
local air pollution control agencies.

Collection and  Evaluation of
Test Results
  The interest of this program was not
in the peak performance values of after-
burners but in typical performance.
Thus, existing literature proved to be of
little value, and persons or agencies
were approached who commonly collect
typical afterburner operating data.
  The attempt to collect typical after-
burner performance data  involved two
sources of data: air pollution  control
agencies, and afterburner manufacturers.
  A number of state or local air pollution
control agencies were contacted. Most
agencies were not  too concerned with
afterburners—they felt that they had to
use their limited funds and manpower
on higher  priority emission sources.
Also, because afterburner emission test
reports may contain proprietary data
(chemical compositions and flow rates),
agencies that had conducted afterburner
emission tests were not always willing
to share the data. Therefore, only one
state or local air pollution control agency
shared test data from an appreciable
number of afterburner emission tests.
  Two approaches were used to solicit
afterburner performance data from
manufacturers. First, 16 manufacturers
were contacted directly; the purpose of
the program was explained and per-
formance  data were requested. Little
meaningful response was  received.
  Secondly, five manufacturers were
approached through their trade associa-
tion, the Industrial Gas Cleaning Institute
(IGCI). Battelle worked with IGCI to
develop a questionnaire that IGCI could
submit to  member afterburner manu-
facturers;  IGCI then screened the re-
sponses to remove  references to
company  names.and forwarded the
sterilized  responses to Battelle. The
responses  were disappointing. Little
test data were  given; in  fact, the  re-
sponses suggest that manufacturers
appeared either not to know the basis
for their designs or not to want to share
their knowledge.
  The results of available afterburner
performance tests from one local agency
are presented in Table 1.
  Caution  must be exercised when
referring to Table 1 for data regarding
afterburner types and operating tem-
peratures. There is no evidence that the
agency differentiated between direct-
flame and thermal afterburners. No
thermal afterburners were listed; this
may be because none were used on the
sources tested. Conversely, some of the
"flame" listings may have included
thermal afterburners.
  In many cases,  the afterburner type
was not specified. It can  be safely
assumed that all afterburners with
operating temperatures shown to be
above 1000°F would be direct-flame or
thermal afterburners.
  Secondly, the recorded afterburner
operating temperatures are suspect. In
some cases the test reports mentioned
that the  recorded value was an after-
burner control setting, not a measured
value.  Also, some reported values are
obviously not meaningful; e.g., catalytic
afterburner operating temperatures
reported to be below 400°F.* Such
values were not recorded in Table 1. As
a whole the operating temperature
values reported in Table  1 cannot be
taken as anything but a guide  to true
operating temperatures.
  Unfortunately, the test reports sum-
marized  in Table 1 do not include two
important values of interest—residence
time and some measure of mixing.
Without  true operating temperatures
and residence time and mixing data,
little  can be  done in analyzing the
important design aspects of afterburners.
  Finally  the afterburner test reports did
not include data on organic, or inorganic,
particulate emissions. Apparently these
emissions are controlled primarily by
visibility  or opacity regulations rather
than by measured emission values.

Evaluation of Available
Afterburner Test Results
  The results of the tests reported in
Table 1 revealed poor afterburner per-
formance. The median efficiency was
about 76 percent. About 38 percent of
the tests gave afterburner efficiencies
of 90 percent or higher. Another 18 per-
cent of the tests gave efficiencies of 70
to 90 percent, and 25 percent of the
tests gave efficiencies from 0  to 70
percent. Finally, 19 percent of the tests
recorded  afterburner efficiencies below
zero percent; that is, outlet  emissions
exceeded inlet emissions.
  National  emissions  of volatile non-
methane organics from sources utilizing
afterburners have been estimated to be
280,350 MTVyr. However if afterburners
are only 76 percent efficient (as is
shown here) instead of 90 percent
efficient, the outlet emission could be
596,000 MT/yr. This value is 315,650
MT/yr greater than the former value.
Hence, based on two assumptions—(1)
that the test data in Table 1 are repre-
sentative of the performance of all
afterburners and (2) that afterburners
are applied to 50 percent of the sources
for which they are considered amen-
able—volatile  nonmethane organic
emissions from afterburner controlled
sources are presently underestimated
by 315,650 MT/yr on a nationwide
basis. This value is equal to about 1.3
percent of total national volatile non-
methane organic emissions and equal
to about 2.0 percent of national man-
related volatile nonmethane organic
emissions.
  Considering the impact on specific
locales, it  can reasonably be assumed
that, for well populated areas, nearly all
volatile nonmethane organic emissions
are from sources amenable to controls.
That is, in populated areas, uncontrolled
sources such as open burning and solid
waste disposal to other than inciner-
ators would be absent and natural
sources would be  present in much
smaller proportions than in the nation
as a whole. Considering that after-
burners are applied to half of the sta-
tionary sources in a populated area, the
impact of  poorer afterburner perform-
ance (76 versus 90 percent) would be an
underestimation of volatile nonmethane
organic emissions from stationary
sources by up to 27 percent, depending
on the distribution of types of industries.
Such an error could have significant
impact on  local air pollution control
strategies  and in the evaluation of air
pollution control efforts.
  Data on afterburner performance on
organic particulates were not available;
hence,  similar values could not be
calculated for these emissions.
Recommendations
  Two major areas in which additional
afterburner research is required are:
  1. Measurements of the performance
     of typical "in-service" afterburners.
"Possibly exhaust gas temperatures were reported
as operating temperatures.
*MT - Metric Tons.

-------
Table 1. Afterburner Performance Tests


Emission Source
1 Coffee roaster
2 Web press
3 Lithographic oven
4 Lithographic oven
5 Resin production
6 Resin production
7 Carbon dryer
8 Lithographic oven
9 Coating Oven
W Coating Oven
1 1 Web press oven
1 2 Coffee roaster
13 Coffee roaster
14 Coffee roaster
15 Wire-coating line oven
16 Lithographic oven
1 7 Lithographic oven
1 8 Coating oven
19 Coating oven
20 Coffee roaster
2 1 Litho-coater drying oven
22 Barrell coaler
drying oven
23 Sheet-metal coating
drying oven
24 Sheet-metal coating
drying oven
25 Pail Mho and coating
drying oven
26 Pail mat line drying oven
27 Painting-line drying oven
28 Painting-line drying oven
29 Coating-line drying oven
30 Coating-line drying oven
3 1 Metal-coatmg-line
drying oven
32 Metal-coatmg-line
drying oven
33. Metal-coating-lme
drying Oven
34. Metal-coatmg-line
drying oven
35 Lithographic oven
36. Lithographic oven
37 Phathalic anhydride tail gas
38 Lithographic oven
39 Asphalt Reactor
40 Paint kettle
4 1 Lithographic oven
42 Lithographic oven
43 Lttho-lme oven
44 Litho-lme oven
45 Lithographic oven
46 Wire coaler
47 Wire coaler
48 Paint kettle
49 Asphalt preheater
and blower
SO Coffee roaster
5f Asphalt saturator
52 Coffee roaster
53 Paint kettle
54 Drum-liner baking
55 Lithographic over
56 Pail line oven
57 Drum painting line
58 Paint-line drying oven
59 Paint manufacture, oven pot
SO Asphalt blower
preheater
61 Asphalt saturator
62 Lithographic oven
63 Paint kettle
Description
of
Afterburner

Flame
Catalytic
Catalytic
Catalytic
Catalytic
Flame
Catalytic
Catalytic
Catalytic
Flame
Flame
Flame
Flame

Flame
Flame
Flame
Flame
Flame

Flame












Flame



Flame

Flame



Flame
Catalytic
Flame
Flame
Catalytic
Catalytic
Catalytic
Catalytic
Catalytic
Catalytic
Catalytic
Flame
Flame

Flame
Flame
Flame
Flame
Flame
Flame

Flame

Flame


Flame
Flame
Flame
Afterburner
Operating
Temperaturew,F


580
690







1000
1100
1200

1300
1050
1060
1200

1400
1180

1200

1400

1240

1420
10OO
1350
1280
1300
1050



1300

1250

1200
1300
1440



702

700
B06
• 637





2600
939
1810
1260
10OO
1290
1300
1140
677





1230
Organics in Inlet Stream
Total
Organics'*'
Ib/day

443




75
1845

245
0195
140
17 1
11.5
>34
1264
401
1138
1164

1610
460

1800

1870




410
550
835
867
269

184

3556

3343

1445
1476
2299
382
11.2OO

956
101O
140
2337
1716
168
997
262
562

180
86.2
68.6
440
179
37
67
101

031
385

499
3040

Reactive
Organics"'
Ib/day
140
48
250
69
00035
0015
06
81 6
24.5
434
0104
16
265
25
0 15
250
80
730
709
27
146
90

511

473




76
69
370
345
98

12

2242

2114

986
1032
498
1048
4515

572
763
11 3
113
1150
132
867
238
223

34
3.6
17.2
a
11 7
0915
20
4.7

0.03
167

03O
2245
72.8

Aldehydes.
pom




















7
7

27

16

17

7
25
22
8
35
39

16





28
25
49


<0 1
13
183
14
4 7
2.0
81
87
Nil
482

89
05
60
Nil
115
IS
19
125
7

1073

1


Organics in Outlet Stream
Total
Organics""
Ib/day

605




71 8
260

71.4
0673
356
250
404
>2 1
716
496
826
486

<45
32

252

<23




248
<12
23
6
107

110

305

259

789
691
370
304
152

470
742
175
573
403
63
1 65
36
46

204
55.9
128
178
689
64
108
715

036
60.4

366
267
1 0
Reactive
Organics"'
Ib/day
245
142
14 1
46
0045
026
1 82
41
21 2
195
0.382
109
73
107
>0 10
290
178
588
429
83
<5
15

178

<15




123
<9
10
2
46

16

107

42 1

580
487
925
76.8
165

78
19O
17
145
297
4.8
1 35
<24
15

24
28 9
25
11 1
108
01
59
53

Oil
362

021
183
049

Aldehydes.
ppm




42
35
13
30
37
34
11 8
42
28
305
22
105
65
43
13
35
1
20

174

2

1

40
49
2
4
1
37

28

82

21 5

122
122
1
143
93
4
59.2
148
27
104
46
49
045
<1
7

36
25
ii a
20
.225
<1
22
20
0

47

8
74
964
984
>990
932

929
-703
86
-39
a
89
-195
•13

-267
78

30
91 8
993

-------
Table 1. (Continued)

64
65
66

67
68
69
70

72
73

74.

75
76
77
78
Emission Source
Lithographic oven
Lithographic oven
Can coating litho
oven
Can coating htho oven
Lithographic oven
Lithographic oven
Can coating oven
and over spray
Can coating oven
and over spray
Metat-coattng. finish oven
Can coating oven
and overspray
Can coating oven
and overspray
Lithographic oven
Lithographic oven
Can coating
Metal-coating, finish oven
Description
of
Afterburner
Flame
Flame
Flame

Flame
Direct Flame
Catalytic

Oil Fired

Direct Flame
Direct Flame

Afterburner
Operating
Temperature*', F

1325
630
1400

1400

120O
14OO

1400

1350
1385
1400
140O
*
Total
Organics**1
Ib/day
481
527
1850

6010
821
80 1
1631

865

4284
496

589

837
1646
143
3788
i,a idiot *ju cap
Reactive
Organics0' Aldehydes.
Ib/day ppm
114
70
41 1

4980
238
651

595

554

2453
\jiyai
Total
Organics^
Ib/day
698
416
410

241
886
121

1270
158

498

34
469
58
123
0
Reactive
Organics""
Ib/day
116
34
152

187
42
56

548

84
t r tsarri
Aldehydes.
ppm
31
17
116

150

Afterburner
Efficiency'", percent
Total
Organics
-45
21
78

960
-8
85
91 4

948

70
68

91 5

972
959
968
Reactive
Organics
-2
51
-270

962
82
91 4

995

966
(a) Descriptions of afterburners were taken from test reports—some were incomplete Presumably, all afterburners with operating temperatures over about 900 Fare direct flame or thermal, and are
not catalytic No distinction was made between direct flame and thermal afterburners

(b) Afterburner operating temperatures are as reported in test reports—some values are afterburner control settings, others may be measured values The reliability of these values is questionable

(d) The definition of reactive organics may have varied during the period represented by these test results, but is generally taken to include olefms, carbonyls, phenols, and some aromatics

Afterburner eff,ciency = ">let value - outlet value
inlet value
2. Studies of the relationships be-
tween afterburner performance
and major design variables, es-
pecially with regard to mixing and
turbulence.
The scarcity of data on typical in-
service afterburners is such that mean-
ingful analysis of the impact of after-
burners on national hydrocarbon emis-
sions is risky. The analysis reported
here used the "best" available source of
afterburner emissions data and showed
that afterburner performance is not
likely to be as good as normally ex-
pected. However, the data base was
small and may be biased by the distribu-
tion of sources within the area served by
this single agency. Also, since basic
design parameters were not recorded,
parametric analyses cannot be per-
formed. Hence, the primary need is for a
well designed field measurement pro-
gram to expand the available data base,
both in breadth and depth.
Secondly, various studies have been
conducted to show the relationship
between destruction of various chemi-
cal species and potential afterburner
characteristics as measured by time/
temperature profiles. However, these
studies have usually defined mixing as
nearly perfect and thus have only studied
chemical kinetics. The physical aspects
of afterburner combustion, mixing, and
turbulence have been largely ignored.
Therefore, a study relating afterburner
performance to mixing and turbulence
will greatly improve the design tools
available to afterburner manufacturers.
Such a program should be carried out
using a mobile afterburner test unit.
Richard E. Barrett and Phillip R. Sticksel are with Battelle Columbus Labora-
tories, 505 King Avenue, Columbus, OH 43201.
John H. Wasser is the EPA Project Officer fsee below).
The complete report, entitled "Preliminary Environmental Assessment of After-
burner Combustion Systems," (Order No. PB 80-215 734; Cost: $ 11.00, sub-
ject 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:
Industrial Environmental Research Laboratory
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
» U.S GOVERNMENT PRINTING OFFICE tW1 -757-01Z/7Z60

-------
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Postage and
Fees Paid
Environmental
Protection
Agency
EPA 335
Official Business
Penalty for Private Use $300
      PS   0000329
      U S EtoVIR FROTLCXTUN AGENCY
      REGION 5  LIBRARY
      230 5  DEARBORN  STREET
      CHICAGO  IL  60604

-------