United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/S8-90/075 Jan. 1991
xvEPA Project Summary
Assessment of the
Controllability of
Condensible Emissions
G. S. Shareef and J. T. Waddell
The report gives results of a study
to gain insights into the condensible
emissions area from an air toxics
perspective, with emphasis on
controllability and chemical
composition of these emissions. The
study: compiled existing data on
condensible emissions; determined
the chemical composition of
condensible emissions, where
possible; identified source categories
that are major emitters of conden-
sibles; evaluated the effectiveness of
various control devices in reducing
condensible emissions; and
evaluated how the performance of
currently available control
technologies can be improved to
better control condensible
emissions.
This Project Summary was
developed by EPA's Air and Energy
Engineering 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
As part of current U.S. Environmental
Protection Agency (EPA) efforts to better
understand and quantify condensible
emissions, this study was initiated to
develop an understanding of condensible
emissions from an air toxics perspective.
The major objectives of the study were
to: (a) develop a data base on
condensible emissions, (b) determine
chemical makeup of condensible
emissions, and (c) evaluate effectiveness
of various control devices in reducing
condensible emissions and identify
modifications to improve performance.
Two data bases were developed from a
review of emissions source test reports
from EPA's Emission Measurement
Branch (Office of Air Quality Planning and
Standards/Technical Support Division)
files and from the State of California. The
Condensibles Data Base contains
information on condensible emissions
covering 43 emission source categories.
The Speciated Condensibles Data Base
focuses on the chemical composition of
condensible emissions. For this study,
the back-half catch of the EPA Reference
Method 5 or its equivalent was
considered to represent the condensible
fraction.
Based on the data contained in the
Condensibles Data Base, source
categories with a relatively high
percentage of Condensibles in the total
particulate catch (i.e., > 50%) included
plywood manufacturing, asphaltic
concrete, electric utilities, fertilizer
manufacturing, and secondary lead
smelting. From the limited data on
chemical composition of condensed
particulate matter, the toxic fraction
(composed of arsenic, beryllium,
cadmium, chromium, lead, mercury, and
vanadium) of condensed particulate
matter was < 1% in most cases.
For many sources in the Condensibles
Data Base, wet scrubbers including
venturi scrubbers, fabric filters,
electrostatic precipitators (ESPs), and wet
ESPs were the commonly employed
particulate matter control devices. The
wide variation in performance of these
devices in controlling condensible
Printed on Recycled Paper
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emissions was attributed to differences in
emission source characteristics such as
temperature, composition, and
concentration. Although limited
performance data were available for
specific control devices, venturi
scrubbers and other wet scrubbers
appeared to be more effective in
reducing condensible emissions
than other control devices. No general
conclusions were drawn regarding
controllability of specific condensible
components because of limited data.
Modifications in control device
operation/design that would affect
potential reductions in condensible
emissions include: (a) operating at lower
temperatures and higher humidity levels
to enhance condensed particulate
formation prior to the control device, (b)
adding an ionizing section before
wet/venturi scrubbers to improve
collection efficiency of the fine
particulate, and (c) using gas conditioning
agents to induce condensed particle
agglomeration.
G. Shareef and J. Waddell are with Radian Corp., Research Triangle Park, NC
27709.
Carlos M. Nunez is the EPA Project Officer (see below).
The complete report, entitled "Assessment of the Controllability of Condensible
Emissions," (Order No. PB 91-125 807/AS; Cost: $17.00, subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
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, NC27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
EPA/600/S8-90/075
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