United States
Environmental Protection
Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S2-85/122 Jan. 1986
&EPA Project Summary
Evaluation of Pilot-Scale Air
Pollution Control Devices on a
Municipal Waterwall
Incinerator
D. N. Albrinck, J. M. Bruck, and F. D. Hall
Field tests were conducted at a 120
ton/day, moving grate, waterwall incin-
erator to evaluate the capabilities of a
pilot fabric filter and pilot venturi scrub-
ber in controlling particulate, trace ele-
ment, and gaseous air pollutants from a
waste-as-fuel process. The Braintree,
Massachusetts Municipal Solid Waste
Incinerator mass burns unprocessed
solid waste in a waterwall incinerator
with steam generation. Both the pilot
fabric filter and a pilot scrubber were
installed, operated, and tested as pri-
mary control devices upstream of the
existing full-scale ESP.
This Project Summary was devel-
oped by EPA's Hazardous Waste Engi-
neering Research Laboratory, Cincin-
nati, OH, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).
Introduction
This study was undertaken to evalu-
ate prototype air pollution control
devices on various waste-as-fuel proc-
esses for the control of potentially
harmful air emissions. Several types of
pollutants have been identified in air
emissions from various resource recov-
ery operations; these include particu-
lates, metals, chlorides, sulfur oxides
(SOX), nitrogen oxides (NOX), and poly-
cyclic organic materials (ROMs).
A literature review of state-of-the-art
technologies (e.g., fabric filter, ESP, and
scrubber) for control of waste-as-fuel
processes revealed that fabric filters
have been successfully applied to pre-
processing operations, and ESPs are
the most common air pollution control
equipment used on cofired boilers and
mass-burn incinerators. Full-scale fabric
filters have not been applied to waste-
as-fuel combustion processes, and wet
scrubbers have been used on incinera-
tors with less success than ESPs.
The Braintree, Massachusetts inciner-
ator was selected for this study because
of the cooperation of the management,
availability of data from a previous Mid-
west Research Institute source assess-
ment project, high reliability of the in-
cinerator operations, and limited facility
modifications required.
Braintree Test Plans and Re-
sults
The Braintree Municipal Incinerator
No. 1, shown in Figure 1, was built in
1971 by Riley Stoker. It is designed to
generate 14,000 kg/h (30,000 Ib/h) of
steam at 1723 kPa (250 psi) and 208°C
(406°F). A specially built pilot fabric filter
was tested along with a pilot scrubber
provided by Neptune-Airpol. Both units
slipstreamed flue gas ahead of the exist-
ing full-scale ESP, and, were operated
over consecutive time periods.
The incinerator was operated de-
pendably throughout the entire test pe-
riod, firing about 4.5 Mg/h (5 tons/h).
Normal "steady-state" operating condi-
tions were maintained, with no attempt
to optimize the system.
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Electro-
static
Precipitator
mi n
parameters can optimize pollutant re-
moval efficiencies.
Figure 1. Braintree municipal incinerator. Braintree, Massachusetts.
The fabric filter was operated at an
air-to-cloth (A/C) range of 0.46 m3/min
per m2 to 0.91 m3/min per m2 (1.5 to 3.0
acfm per ft2). The unit was equipped
with reverse air, mechanical shake, or a
combination of the two for cleaning the
fabric. Figure 2 shows paniculate re-
moval efficiency as a function of pres-
sure drop and (A/C) ratios. For a specific
A/C ratio particulate removal efficiency
seems to increase with increasing pres-
sure drop. The effect of A/C on particu-
late removal capabilities, within the A/C
range tested, is unclear. The fabric filter
was precoated with hydrated lime over
the entire test period, in an attempt to
improve gaseous pollutant removal.
Chloride and SOX removal efficiencies
improved and roughly doubled (ap-
proximately 28 percent and 37 percent
removal for chloride and SOX, respec-
tively) over the results of an earlier test
series at Ames, where no precoat addi-
tive was used.
The pilot scrubber used at Braintree
was less effective than expected in con-
trolling particulates. One cause may be
poor mist elimination in the separator
section of the unit. Figure 3 presents the
particulate removal efficiencies as a
Function of venturi pressure drop and
!iquid-to-gas (L/G) ratio. It appears from
the graph that at low L/G ratios, increas-
ing pressure drop improves collection
efficiency. At high L/G ratios, an in-
crease in collection efficiency with in-
creasing pressure drop is not apparent.
The removal of chloride with the venturi
scrubber was highly effective (94 to 99
percent).
Conclusions
At Braintree, the fabric filter operated
at a slightly lower than expected effi-
ciency for particulate removal; how-
ever, when the fabric was precoated
with lime, SOX and chloride removal ca-
pabilities doubled compared with tests
without precoatint, performed in an
earlier test series at Ames. Particulate
and metal removal efficiencies for the
scrubber were much lower than for the
fabric filter, but gaseous chlorides were
removed with 96.5 percent efficiency
(by the scrubber).
in summary, conventional state-of-
the-art air pollution control devices
were found to be effective in controlling
the pollutants investigated: particulate,
trace metals, SOX, and halides. The fab-
ric filter was more efficient in con-
trolling particulate emissions than
gaseous pollutants. A venturi scrubber
was very effective in removing gaseous
pollutants. Varying specific operating
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F. D. Hall, J. M. Bruck, and D. N. Albrinck are with PEDCo Environmental, Inc..
Cincinnati, OH 45246.
Robert A. Olexsey and Michael Black are the EPA Project Officers (see below).
The complete report, entitled "Evaluation of Pilot-Scale Air Pollution Control
Devices on a Municipal Waterwall Incinerator, "(Order No. PB 86-113 792/AS;
Cost: $ 11.95, 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 Officers can be contacted at:
Hazardous Waste Engineering Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
BULK RATE
POSTAGE & FEES P/
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use S300
EPA/600/S2-85/122
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