United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S2-86/077 Jan. 1987
Project Summary
Instrumental Monitoring of
Non-Methane Hydrocarbons at
a Hazardous Waste Incinerator
K. T. Menzies and J. W. Adams
As part of the Resource Conservation
and Recovery Act (RCRA), the U.S. EPA
has promulgated regulations for facilities
that treat hazardous wastes by incinera-
tion. Compliance with the performance
standards specified in the regulations Is
demonstrated by conducting a trial burn,
which involves measurement of particulate
emissions, hydrochloric acid (HCI) emis-
sions, and Destruction and Removal Effi-
ciency (DRE) for the Principal Organic
Hazardous Constituents (POHCs) of the
waste. During subsequent routine operat-
ing burns, carbon monoxide (CO) is the
only chemical species for which effluent
concentrations are monitored. It might be
desirable to supplement this measure of
overall combustion efficiency with an or-
ganic monitoring technique that could pro-
vide a more direct measure of PHOC emis-
sions and thus of DRE.
The objective of this field program was
to evaluate the reliability of non-methane
hydrocarbon analyzers as a continuous
indicator of the DRE of a hazardous waste
incinerator.
During a 5-day test period, two non-
methane hydrocarbon analyzers (Columbia
Scientific Industries Corporation [CSI]
Model 500-2E and HMD Systems, Inc.,
Model 201-250) were evaluated. During
the test period, the sample conditioning/
analysis system operated reasonably well.
The non-methane hydrocarbon concen-
trations measured by the CSI and HNU
analyzers were observed to be about 20%
of the total hydrocarbon analyzer concen-
tration. The ratio of non-methane hydro-
carbon concentrations observed by the
CSI and HNU analyzers was observed to
be about equal to 1.
Over the range of operating conditions
and combustion efficiency observed in
this field study, the non-methane hydro-
carbon appeared to be independent of CO
concentration.
This Project Summary was developed
by EPA's Air and Energy Engineering Re-
search Laboratory, Research Triangle Park,
NC, to announce key findings of the re-
search project that is fully documented in
a separate report of the same title (see Pro-
ject Report ordering information at back).
Introduction
The principal objectives of this program
were to evaluate the reliability of non-
methane hydrocarbon analyzers as a con-
tinuous indicator of hazardous waste in-
cinerator performance. The tasks under-
taken included: (1) the fabrication of a
sample extraction/conditioning system for
transfer of combustion gas to the hydro-
carbon analyzers; (2) evaluation of the
reliability of two non-methane hydrocar-
bon analyzers under conditions of contin-
uous operation at a hazardous waste in-
cinerator; and (3) determination of the cor-
relation of non-methane hydrocarbon con-
centration with combustion efficiency.
Test Facility
The hazardous waste incinerator utilized
for this field program is operated by the
Cincinnati Metropolitan Sewer District.
The incinerator is equipped with a rotary
kiln designed to handle solid or semi-solid
wastes. However, only liquid wastes were
fired during the testing. The kiln and fur-
nace are connected to a single combustion
chamber to provide residence time for the
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combustion gas. Gases leaving the com-
bustion chamber are quenched with water
and passed on to a venturi scrubber for
particulate removal and through a sieve
tray caustic scrubber for HCI removal.
From the sieve tray scrubber, the gases are
directed through a mist eliminator before
they leave the stack. Liquid effluent from
the scrubbing system goes to the treat-
ment plant, and bottom ash is sluiced with
water into a lagoon.
During the 5-day test period, the waste
feed was a liquid containing 11-12.5%
chlorine by weight. The waste feed rate
was reported to be in the range of 2920
- 3740 kg/hr. The mean temperature was
1220-1320 °C.
Previous trial burn testing at this facility
had demonstrated it to be in compliance
with the ORE performance standard when
burning waste mixtures of 3-16% chlorine.
Sample Extraction/Conditioning
System
The sample conditioning system con-
sisted of a heated microfibre filter tube and
Teflon transfer line (30 m long). The sys-
tem also included a splitter which permit-
ted some of the gas to be cooled to 4°C
in a small refrigerated condenser.
Hydrocarbon Analyzers
Two non-methane hydrocarbon analyz-
ers, Columbia Scientific Industries Cor-
poration (CSI) Model 500-2E, and HNU
Systems, Inc. (HNU) Model 201250 were
utilized. The CSI instrument determines
non-methane hydrocarbons by a dif-
ference method. A flame ionization detec-
tor (FID) is used to quantify organics in the
gas sample "as received" and after treat-
ment with a catalytic oxidizer that con-
verts all species other than methane to
C02; the difference between these two
readings gives non-methane hydrocar-
bons. The HNU instrument uses a detec-
tion system (photoionization detection,
PID) that does not respond to methane.
Results of the Test Program
During a 5-day test period, the sample
conditioning/transfer system operated
90% of the time without failure, except for
the failure of the heater controller in the
filter box, caused by vibrations from the
stack. Connecting the heater box to the
stack with a flexible line would preclude
this problem.
Calibration of the hydrocarbon analyzers
with a 17.3 ppm butadiene span gas and
12% O2 zero gas by passing the calibra-
tion gases through the conditioning sys-
tem was observed to provide concentra-
tions identical to those obtained by inject-
ing calibration gases directly at the back
of the analyzers. The observed concentra-
tions of the span and zero gases did no1
vary by more than ±20% over 5 days.
The two non-methane hydrocarbon
analyzers operated continuously (with one
exception, due to a general power failure]
over the 5-day test period.
The non-methane hydrocarbon concen-
trations measured by the CSI and HNL
analyzers were observed to be about 20%
of the total hydrocarbon concentration.
The ratio of non-methane hydrocarbon
concentrations observed by the CSI anc
HNU analyzers was observed to be aboul
equal to 1; i.e., the analyzers respondec
about equally to the non-methane
hydrocarbons present.
K. T. Menzies and J. W. Adams are with Arthur D. Little. Inc., Cambridge. MA
02140.
Merrill D. Jackson is the EPA Project Officer (see below).
The complete report, entitled "Instrumental Monitoring of Non-Methane Hydro-
carbons at a Hazardous Waste Incinerator," (Order No. PB 87-102 331 /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 Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45263
Official Business
Penalty for Private Use $300
EPA/600/S2-86/077
0000329 PS
s
*GE
CHICAGO
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