United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S9-88/026 Oct. 1989
c/EPA Project Summary
Proceedings: 1987 Joint
Symposium on Stationary
Combustion NOX Control,
New Orleans, LA, March 1987
B. B. Emmel, Compiler
The two-volume proceedings docu-
ment the 1987 Joint (EPA and EPRI)
Symposium on Stationary Combus-
tion NOX Control, held March 23-26,
1987, in New Orleans, LA. The papers
discuss: low-NOx combustion devel-
opments (e.g., reburning and burner
design modifications); coal-, oil-, and
gas-fired boiler applications; flue gas
treatment processes; fundamental
combustion studies; and Industrial
and commercial applications. Also
presented were manufacturers' up-
dates of commercially available tech-
nology and an overview of environ-
mental issues involving NOX control.
This Protect Summary was devel-
oped by EPA's Air and Energy Engi-
neering Research Laboratory, Re-
search Triangle Park, NC, to announce
key findings of the research project
that Is fully documented In two
separate volumes of the same title
(see Project Report ordering informa-
tion at back).
Introduction
The 1987 Joint Symposium on Station-
ary Combustion NOX (nitrogen oxides)
Control was held March 23-26, 1987, in
New Orleans, LA. The symposium, jointly
sponsored by EPRI and EPA, was the
fourth of its kind devoted solely to the
discussion of the control of NOX emis-
sions from stationary sources. Topics dis-
cussed included Iow-N0x combustion
developments (e.g., reburning and burner
design modifications), coal-, oil-, and gas-
fired boiler applications, flue gas treat-
ment processes, fundamental combustion
studies, and industrial and commercial
applications. Also presented were manu-
facturers' updates of commercially
available technology and an overview of
environmental issues involving NOX con-
trol.
The 4-day meeting was attended by
persons from 14 nations. Forty-nine pa-
pers were presented by EPRI and EPA
staff members, utility company represen-
tatives, boiler and related equipment
manufacturers, research and develop-
ment groups, and university representa-
tives.
The Proceedings are in two volumes.
Volume 1 contains papers from:
• Session I. Background and
Environmental Issues
• Session II. Low-NOx Combustion
Development
• Session III: Manufacturers' Update of
Commercially Available
Technology
• Session IV: Coal-Fired Boiler
Applications
Volume 2 contains papers from:
• Session Va: Flue Gas Treatment
• Session Vb: Fundamental
Combustion Studies
• Session VI: Cyclone-Fired Boilers
• Session Vila: Oil- and Gas-Fired
Boilers
• Session Vllb: Industrial and
Commercial Applications
The remainder of this Summary con-
sists of abstracts of the 49 technical
papers presented at the symposium. To
conserve space, authors' addresses are
-------
listed alphabetically at the end of the
Summary, rather than before each
abstract.
Volume 1
Session I: Background and
Environmental Issues
The New Environmental Agenda
and the Coming Commitment to
NOX Control
Richard E. Ayers
As the recent ideological approach to
environmental problems wanes, a new
environmental agenda for the remainder
of this century is emerging. Controlling
NOX emissions from stationary sources
— a pollutant with serious effects on
public health, environmental integrity, and
esthetic experience — is part of this
agenda. Development of new technology
is welcome. But political leaders must not
be permitted to use technological change
as an excuse for avoiding the use of
existing NOX control technologies now.
Decline of Boreal Montane
Forest Ecosystems in Central
Europe and the Eastern North
America—Links to Air Pollution
and the Deposition of Nitrogen
Compounds
Robert I. Bruck
Recently presented evidence of
anomalous growth declines and dieback
of eastern forests has captured public
concern and strengthened the call to
resolve the longstanding question of the
role of atmospheric deposition in the
decline of forest trees. This paper
summarizes recent evidence relevant to
determining if there are effects of atmos-
pheric deposition on forests of the
eastern U.S. A scenario might involve
various forms of concentrated pollution
being deposited via cloud deposition,
causing above- and below-ground nutri-
ent and microbial imbalances or direct
physiological aberrations to spruce and
fir trees. These chronic perturbations
could lead to a predisposition of the eco-
system, to the effects of many indigen-
ous pathogens and insects, and/or weak-
en the trees' resistance to the effects of
severe climate. Continued research to in-
tegrate the findings of long term studies
with relevant atmospheric monitoring data
will create a clearer picture of the poten-
tial of atmospheric pollution to affect U.S.
forest resources.
An Overview of Environmental
Issues Related to Nitrogen
Oxides in the Atmosphere
Charles Hakkarinen
Atmospheric NOX compounds, includ-
ing N20, NO, and NO2, have been impli-
cated in a variety of environmental
effects, from both their direct emission to
the atmosphere and their role in the for-
mation of secondary compounds, such as
ozone and nitric acid. High temperature
fossil fuel combustion is a principal
source of atmospheric NOX emissions,
hence the electric utility industry has a
strong interest in understanding their en-
vironmental fate. This paper is an over-
view of the current state of scientific
knowledge on the transport, conversion,
and fate of NOX compounds in the atmos-
phere. Emphasis will be given to: the re-
lationship between NCyozone and effects
on human health; the role of nitrogen
compounds/ozone in the perceived de-
cline of some North American forests; the
contribution of nitrogen compounds to the
formation of acidic precipitation; and the
role of NOX (principally, N20) in regu-
lating global climate (the "greenhouse
effect") and influencing the stratospheric
ozone layer (the "polar ozone hole"). The
paper summarizes major research under-
way at EPRI and elsewhere that
addresses environmental issues related
to NOX.
The Role of Nitrous Oxide (N2O)
in Global Climate Change and
Stratospheric Ozone Depletion
Dennis A. Tirpak
Several recently completed scientific
assessments have concluded that there
is a significant potential for global atmos-
pheric change — climate change and
stratospheric ozone depletion — to occur
in the next few decades. N2O is a critical
element in both issues. Although the
problem of global climate change was
once synonymous with COg, there is
growing recognition of the role of other
trace gases. Chlorofluorocarbons, N2O,
methane, and other trace gases now
account for roughly half of the warming
from greenhouse gases in the atmos-
phere, and by the year 2030 may lead to
twice as much warming as from C02
alone. The U.S. Congress has asked the
U.S. EPA to prepare a report on policy
options to stabilize these trace gas con-
centrations. This paper will evaluate the
role of NO2 in global climate change anc
stratospheric ozone depletion. It wil
summarize trends in N2O concentrations
review our understanding of current an<
projected emission sources and emissio
factors, discuss the twin issues of climat
change and ozone depletion, an
recommend topics for further study.
Overview of Recent Developmer
in NOX Control in Europe
O. Rentz and R. Leibfritz
Based on the emission control legist
tion in some European countries, rece
developments are presented leading
the current status of NOX abatement tec
nologies and their application to static
ary sources (power plants and industi
processes). The state of DeNOx imp
mentation in Europe in the field of (
mary and secondary NOX emission a
trol is outlined. This includes informat
on initial status at both full-scale and p
plants, available and applied control te
nologies, transfer problems with regar<
site specific conditions, advance prob
solutions, and state of commission
The future application of DeNOK tech
ogies to industrial processes is bri
outlined. Investment and cost figures
disclosed.
Session H: Low-NOx Combusi
Development
Large Scale Testing and
Development of the R&W Low
NOX Burner
M. J. Clark, A. D. LaRue, A. D. L
and D. Eskinazi
Due to environmental concerns,
fuel power plants built prior to
Source Performance Standards (f>
may be required to reduce NOX
sions. A large segment of these uni
equipped with cell burners whic
producing relatively high NOX em
in the 1.0 to 1.8 lb/1Q6 Btu i
Babcock & Wilcox and EPRI have
oped a low NOX burner that is c
retrofittable to cell burner units
paper describes the continued d<
ment of this new burner. Results
cent pilot combustion tests (100
Btu/hr) conducted at EPA's Large
tube Simulator (LWS) agree w€
prior smaller-scale pilot perfori
NOX reductions were typically !
-------
while achieving combustion efficiency of
3.5% in the test furnace. A full scale
LOW NOX Cell was installed at Dayton
Power and Light's Stuart Station and has
been in operation since March 1985. The
Low NOX Cell retrofit involves near-burner
coal piping operation and mechanical
reliability has been demonstrated over a
2-year period. A full scale retrofit demon-
stration is planned to confirm the com-
mercial viability of this burner in a full
scale retrofit.
Low NOX Developments on an
Integrated Combustion and
Environmental Test Facility
J. Vatsky and R. McMillan
A test facility, equipped for a wide
range of combustion and emission-con-
trol related testing, has been in operation
or about 18 months, firing a wide variety
of pulverized fuels, from subbituminous
coals to very low volatile fuels such as
jetroleum coke. Initially, an extensive test
jrogram was performed with both petrol-
>um coke and bituminous coal with an
irch-fired furnace configuration. More
•ecently, testing has begun with a two-
jurner high horizontally fired configura-
ion. Although these programs were
esigned to evaluate NOX emissions, and
evels of about 0.15 lb/106 Btu have been
ibtained, the Combustion and Environ-
mental Test Facility (CETF) is also
lesigned to facilitate testing of SO2 con-
rol systems. This paper describes the
DETF and summarizes initial results ob-
ained from both the arch- and horizon-
ally fired modes.
Development of Overfire Air
Design Guidelines for Front-Fired
toilers
tobert A. Lisauskas, Claire E.
rtcHale, Rui Afonso, and David
•skinazi
Experimental flow model data and
ichnical and economic studies have
een used to develop design guidelines
>r overfire air (OFA) NOX control sys-
ms. Conventional and novel OFA con-
jurations were investigated in a 1/12-
:ale furnace model using detailed tem-
»rature and velocity maps to quantify
rerfire air injection and mixing. Data
lalyses focused on translating the flow
odel test results into practical designs
r front-fired utility boilers. Based on the
perimental results, the feasibility of
Irofitting new OFA configurations on a
specific utility boiler was examined. The
results for several test configurations are
used to develop preliminary OFA design
guidelines for front-fired boilers. For
traditional design configurations with one
OFA port located over each burner
column, the best mixing occurs at an
injection to furnace velocity ratio of 4 to
6. A significant improvement in upper
furnace mixing can be achieved by
adding wing OFA ports and biasing the
air flow and velocity from the center to
the wing ports.
Furnace Design and Application
on Low NOX Pulverized Coal
Combustion
Takashi Kiga, Shigehiro Miyamae,
Keiji Makino, and Hiroshige Ikebe
Coal properties such as fuel ratio and
fuel nitrogen are generally well-known to
affect NOX emission. We have already
developed a low NOX pulverized coal
burner which gives 150 ppm of NOX or
less for Japanese domestic coal with
conventional staged firing; however, most
of various kinds of imported coals
ensured significantly higher NOX emis-
sion with a conventional furnace. There-
fore, we attempted to develop a low NOX
furnace, applying the INPACT method,
according to results of fundamental re-
search. Applying this method to a 600
MW utility boiler, we obtained low NOX
emission of less than 150 ppm of the
guarantee value for coals ranked from 1.5
to 2.2 as fuel ratio. A remarkable NOX
reduction of less than 100 ppm was also
obtained. This paper introduces the
fundamental furnace design concept and
its application results.
Gas Reburning-Sorbent
Injection—A Combined NOX/SOX
Control Technology
W. Bartok, B. A. Folsom, and F. R.
Kurzynske
Gas Reburning-Sorbent Injection (GR-
Sl) involves co-firing pulverized coal with
natural gas in combination with sorbent
injection and/or coal cleaning to allow for
cost effective reduction of acid rain
precursor emissions (NOX and SOX) from
pre-NSPS coal-fired utility boilers. This
would provide the utility industry with
flexibility in fuel selection to satisfy
potential acid rain control legislation. This
paper describes a demonstration project
which will be cooperatively funded by the
Department of Energy, the Gas Research
Institute and the State of Illinois
Department of Energy and Natural
Resources, to demonstrate GR-SI on
three coal-fired utility boilers in Illinois.
GR-SI will be applied to one each of wall,
corner, and cyclone fired boilers with
overall reduction targets of 60% in NOX
and 20% in SOX emissions. The overview
of the planned demonstration project will
be discussed, including design consider-
ations and economic projections for GR-
SI applications.
Pilot Scale Studies on the
Application of Reburning for NOX
Control
J. M. McCarthy, S. L. Chen, W. R.
Seeker, and D. W. Pershing
This paper describes a pilot scale ex-
perimental study which addressed para-
metric and mixing effects of the reburn-
ing process, an in-furnace NOX reduction
technology, and provides scaling infor-
mation and design and operation
guidelines for application of reburning
under a wide variety of conditions for
coal- and oil-fired boilers. The results
demonstrate the potential of reburning for
NOX reduction, and indicate that impor-
tant parameters include: primary zone
NOX level; primary zone burnout; reburn-
ing zone time, temperature, and stoichio-
metry; and reburning coal transport
medium. Rapid dispersion of the reburn-
ing fuel is desirable for primary NOX
incineration but can lead to an overall
decrease in efficiency if the reburning
fuel contains fuel nitrogen and is carried
by an oxygen-rich medium. Recirculated
flue gas is the optimal reburning coal
transport medium, but efficient NOX
reduction with air transport can be
achieved if higher reburning fuel ratios
and optimal reburning mixing rates are
employed. Natural gas is more effective
than either coal or heavy fuel oil for
reburning, especially at low primary NOX
concentrations. Reburning with coal or
natural gas has little adverse affect on
burnout performance. Comparison of pilot
scale results and bench scale data shows
that parametric effects are independent
of scale and that a 50% reduction in
emissions is achieved with 20% coal
reburning at normal primary NOX levels.
Reburning with Low and Medium
Btu Gases
S. J. Bortz and G. R. Often
Experiments have been conducted in a
0.5 x 106 Btu/hr test furnace to assess
-------
the effectiveness of low and medium Btu
gases as returning fuels. These fuels,
produced by coal gasification, have only
trace amounts of hydrocarbons; the
combustion fraction is mainly H2 and CO.
Situations where gasification fuels may
be of interest for reburning would be
cyclone combustors which used crushed
coal as a fuel, or boilers where there is
insufficient residence time for reburning
with coal. The experimental results show
that the gasification fuels can reduce NOX
created in the primary flame although not
as effectively as hydrocarbon fuels.
Typically, the gasification fuels gave 20-
30% reduction of primary zone NOX
compared to 60-70% for natural gas. If
the primary zone NOX emissions are
controlled by reducing the primary zone
stoichiometry to between 1.0 and 1.05,
60% overall NOX reduction (compared to
an uncontrolled flame) can be achieved
with 15-20% use of simulated Lurgi
reburning fuel. Under the Same condi-
tions, nearly 80% overall NOX reduction
was achieved with natural gas reburning.
Session ///: Manufacturers'
Update of Commercially
Available Technology
1987 Update on NOX Emissions
Control Technologies at
Combustion Engineering
M. S. McCartney, A. Kokkinos, R. D.
Lewis, T. D. Hellewell, and M. B.
Cohen
As the owners and operators of fossil
fuel steam generators plan for the 1990s
new emphasis is being placed on the
control of NOX emissions. This emphasis
is the result of a resurgence in the
concern, both domestically and inter-
nationally, for the effects that NOX
emissions may have on the environment.
At Combustion Engineering (CE), work is
continuously underway to support these
owners and operators. As shown in
previous Joint NOX Control Symposia, CE
has a diverse array of NOX Reduction
Technologies available to address a
range of possible reductions dictated by
future regulations. These technologies
have been developed by CE and Mitsu-
bishi Heavy Industries (MHI); MHI-devel-
oped technologies have been licensed to
CE. A synopsis of each of these tech-
nologies and the application and oper-
ating experience related to them is
presented here.
Update of NOX Control
Technologies at Riley Stoker
C. E. McHale and R. A. Lisauskas
Recent design and operating exper-
ience with Riley Stoker low-NOx com-
bustion systems in pilot scale and com-
mercial furnaces is reviewed. The perfor-
mance of several commercial Iow-N0x
burner installations in wall- and Turbo-
fired furnaces is described. Both emis-
sions reductions from uncontrolled levels
and the impact of the combustion
process modifications on furnace temper-
atures are discussed. Pilot scale results
focus on in-furnace NOX and S02 control
processes such as reburning and sorbent
injection. Recent activities include CCV
burner design refinements, and devel-
oping staged combustion systems for
utility boilers, industrial stoker-fired
boilers, and circulating fluidized-bed
combustors. Since jet aerodynamics
influence combustion and NOX reduction
efficiencies, two-phase jets in furnace
enclosures are discussed.
Industrial and Utility Boiler Low
NOX Control Update
Joel Vatsky and Edmund S. Schindler
NOX control has been passing through
various phases as the regulatory and
commercial climate has changed since
the early 1970s. During the decade of the
70s, emphasis by boiler manufacturers
was on developing and field demon-
strating NOX controls to meet the New
Source Performance Standards of 1971
and 1979. More recently, with the
reduced need for new utility generating
capacity, emphasis has shifted to retro-
fittable technologies to meet pending
acid rain control legislation. This paper
discusses field experience with Foster
Wheeler's low NOX coal burner, which is
an inherently retrofittable design, on
industrial and utility boilers. New con-
cepts and their potential uses are also
outlined.
NOX Control Update-1987
Albert D. LaRue and Paul L. Cioffi
Babcock & Wilcox is expanding its low
NOX technology and product lines to
include systems directly suited for un
controlled sources and for an increasing
variety of new boiler applications. Tru
low NOX cell burner has successful!'
completed two scales of combustio
testing and initial field trials, and awaits
full boiler demonstration. The XCL bums
was developed to reduce NOX belo<
existing low NOX burner capabilities whil
providing individual burner air flo
measurement and other features I
improve performance. Reburning is beir
investigated as a NOX control measure f<
cyclone-fired boilers. NOX emissions a
controlled with gas- and oil-fired units i
use of PG-Dual Register Burners cor
bined with NOX ports and gas recirci
ation. Further NOX reduction can I
achieved by use of In-Furnace N<
Reduction. Fluid beds provide N
control by virtue of the combusti
methodology, and lower NOX levels c
be reached by staging. Refuse systei
often face a wide range of emission lii
tations, and the Controlled Combust
Zone (CCZ™) furnace offers potential
improved combustion and lower N
when firing refuse-derived fuel. An upd
is provided on the technology and pr
ucts used by B&W to control emissi
in these applications.
Session IV: Coal-Fired Boiler
Applications
The Federal Clean Coal
Program
Jack S. Siegel
The Department of Energy's C
Coal Technology Program is broad
scope than just the control or prove
of pollutants from coal using machin
also addresses the energ» needs c
U.S. economy; i.e., coal technoh
which can compete with oil and gi
markets which are now dominated I
and gas; coal technologies whicf
allow utilities to cut the long lead
now necessary to design and con
conventional coal-fired boilers with s
bers; and coal technologies whic
only control SO2 and NOX to NS
better levels, but which also are
efficient and produce more easily
posal wastes than conventional
nologies. It is our objective to e>
the scope of this effort, prese
overview of the R&D activity, irw
the recently initiated clean coal c
-------
tration program, and discuss the attri-
jtes of the technologies which should
isure that, once demonstrated, they will
je used commercially.
Development Status of B&W's
Second Generation Low NOX
Burner—The XCL Burner
Jbert 0. LaRue, Michael A. Acree,
id Charles Masser
Due to the national concern with acid
in, the U.S. NOX emission standards
lay become more stringent for new
ources, and uncontrolled sources may
ce NOX emission limits. B&W has con-
equently proceeded to develop a
econd generation low NOX pulverized
oal (PC) burner suitable for new or
trofit applications. A primary objective
to minimize NOX by burner design to
void slagging and corrosion concerns
sociated with staged furnace operation.
evelopment of the XCL burner stemmed
om the technology of Babcock Hitachi's
T-NR burner design. The development
•ogram was cosponsored by the EPA,
id consisted of full scale (80 x 106
u/hr) tests of a standard Dual Register
jrner, an HT-NR burner, and an XCL
jrner. Air flow tests were conducted to
aracterize flow patterns and improve
rirl efficiency, and combustion tests
ere performed to evaluate and minimize
nissions. The XCL burner proved
.Jabte of NOX emissions (unstaged) of
3-0.5 to/106 Btu with high efficiency and
Jjustable flame shape. Consequently, a
II complement of XCL burners were
trofitted to Ohio Edison's Edgewater
lit 4 for the EPA Limestone Injection
ultistage Burner (LIMB) demonstration.
le paper describes development and
ild results with the XCL burner.
ductions in NOX Emissions
3m a 500 MW Corner Fired
5iler
W. Allen, W. J. D. Brooks, N. A.
rdett, F. Clarke, and G. Foley
The Central Electricity Generating
ard is investigating methods for
lucing the emissions of NOX from
sil-fired power stations. Low NOX tech-
ogies usually involve radically different
nbustion regimes within the boiler
npared to conventional units; there-
i, it is necessary to investigate their
t-effectiveness by undertaking large
le and long term trials. This paper
Jrts on the results of a programme
undertaken to investigate the character-
istics of the "rich-fireball" technique
installed in a 500 MW(e) coal fired boiler
at Fiddler's Ferry Power Station, England.
Data are presented showing the impact of
operational parameters on NOX emis-
sions. It is concluded that the introduction
of this technique has resulted in a
reduction of NOX emissions of 31-38%,
depending on the mills in service.
Application of Mitsubishi
"Advanced MACT" In-Furnace
NOX Removal Process at Taio
Paper Co., Ltd., Mishima Mills
No. 18 Boiler
M. Araoka, A. Iwanaga, and M. Sakai
Mitsubishi Heavy Industries, Ltd. has
been engaged in the research and devel-
opment of new technology concerning
the prevention of air pollution. In the field
of low NOX combustion technology, we
have already developed and utilized
many countermeasures; for example,
super low NOX PM burners and MACT
systems which have already been intro-
duced at former symposiums. This time,
we have successfully developed and put
into practical use the "Advanced MACT"
system. This paper introduces the outline
of this "Advanced MACT" system and its
application and operating experience at
Taio Paper Co., Ltd., Mishima Mill No. 18
Boiler.
Operating Experiences of Coal
Fired Utility Boilers Using Hitachi
NOX Reduction Burners
Tsuneo Narita, Fumio Koda, Tadahisa
Masai, Shigeki Morita, and Shigeru
Azuhata
Babcock-Hitachi K.K. has replaced
Dual Register Burners with Hitachi NOX
Reduction burners (HT-NR) on two coal
fired 200 MWe boilers. The HT-NR
burner was developed, as previously re-
ported, to apply the concept of In-Flame
NOX Reduction. The two retrofitted
boilers have achieved further NOX reduc-
tion, without increased unburned carbon
contents or any other operating prob-
lems. Actual NOX emissions depend on
the volatile matter content of the coal:
with highly volatile coal, emissions range
from 70 to 75 ppm (6% O2). Five dif-
ferent coals are being fired in these units.
Rapid ignition and flame stabilization are
enhanced by use of a new type ceramic
stabilizer. Even lower levels of NOX and
unburned carbon can be achieved by
increasing the coal fineness.
Long-Term Versus Short-Term
Data Analysis Methodologies—
Impact on the Prediction of NOX
Emission Compliance
Lowell L. Smith, Wallace S. Pins, III,
Randall Rush, and Timothy Flora
Over the last two decades, con-
siderable NOX data from utility and indus-
trial boilers have been accumulated. The
data sources range from short-term test
results to data obtained from continuous
emission monitors from Subpart Da utility
boilers. Depending upon the ultimate use
of these two types of data, different inter-
pretations of the emissions results can be
obtained. This can have far reaching
impacts if the interpretation of the data is
used to establish the long-term effective-
ness of NOX control technologies or to
establish new or revised emission stan-
dards. This paper discusses the potential
ultimate uses of both short- and long-
term data. The value of both is discussed
in terms of their use for establishing
emission control trends, operating and
retrofit guidelines, and emission standard
setting. Statistical analysis methodologies
are presented for interpreting long-term
data, and illustrations of Time Series
Analysis are presented for interpretation
of these data.
Engineering and Economic
Analysis of Retrofit Low-NOx
Combustion Systems
R. A. Lisauskas, R. D. Snodgrass, S.
A. Johnson, and D. Eskinazi
The feasibility of retrofitting low-NOx
combustion controls on four utility wall-
fired boiler designs has been evaluated.
This evaluation included an engineering
analysis of all equipment modifications,
and a cost estimate for each retrofit
option. Consideration was given to boiler
physical limitations and operating con-
straints, as well as achieving NOX reduc-
tion. NOX emission predictions were
based on correlations developed from
both field installations and large pilot-
scale combustion tests. The following
Iow-N0x combustion processes were
evaluated: Low-NOx burners, Conven-
tional air staging (Overfire air), Advanced
air staging (Overfire air), and Reburning.
Costs are presented in terms of $/kW,
mills/kWh, and $/ton of NOX removed.
The cost of retrofit NOX controls was
-------
found to vary with unit size and retrofit
complexity. Depending on the level of
boiler modifications required, the capital
cost of retrofit combustion controls can
vary from less than $3 to more than
$20/kW.
The Influence of Fuel Properties
and Boiler Design and Operation
on NOX Emissions
J. H. Pohl, G. C. Dusatko, P. C.
Orban, and R. W. McGraw
Methods to predict the dependence of
NOX emissions on coal properties, burner
design and operation, and boiler design
and operation are unreliable, compli-
cated, or both. This paper determined the
functional dependence of NOX emissions
on a number of these parameters using
data available in the literature. The func-
tional dependences were then used to
successfully explain the changes in NOX
emissions observed for: (1) a 660 MWe
boiler firing two bituminous coals with
volatile contents of 26.3 and 18% as
received, and (2) two wall-fired 30 MWe
units and a 137 MWe tangential unit firing
a single coal with a volatile content of
24% as received. The change in the NOX
with coal, primary air velocity, load, and
excess oxygen content was explained
using the dependences derived in this
paper.
Volume II
Session Va: Flue Gas Treatment
Current Status of SCR in Japan
Yasuyuki Nakabayashi and Rikiya Abe
Selective Catalytic Reduction (SCR) of
NOX is widely applied to utility and indus-
trial boilers in Japan. Among utility
boilers, 99 units (about 110 x 106 Nm3/h)
have been equipped with SCR including
22 units of coal firing boilers (about 20 x
106 Nm3/h). Among industrial boilers, 31
units (about 3.3 x 106 Nm3/h) have also
been equipped with SCR (as of April
1986). SCR installation started in 1977 for
oil and gas and in 1979 for coal firing
boilers. These operating experiences
suggest that the cost and performance of
SCR should be discussed again, because
the catalyst itself (life, volume require-
ment, etc.) has been improved remark-
ably. This paper will describe those
factors from a utility standpoint.
Operating Experience with the
SCR DeNOx Plant in Unit 5 of
Altbach/Deizisau Power Station
P. Necker
The SCR DeNOx plant in Unit 5 (420
MW) of Altbach-Deizisau Power Station
has been in operation since late 1985.
The plant represents a retrofit to an
existing plant and is designed as a partial
flow plant (1.1 x 106 m3/h at 80% boiler
load). The experience obtained after
6,000 hours of operation (by the end of
1986) has shown that it is possible to
observe the 200 mg NCym3 limit value
stipulated in Germany when considera-
tion is given to the accompanying con-
ditions illustrated with full flow plants. The
demands placed on the partial flow plant
of Unit 5 are particularly high. The reduc-
tion in activity of the catalytic converter is
within the expected range after 6,000
hours of operation. A partial air preheater
wash carried out on a test basis
produced air preheater water which had a
high NH3 content initially only. The waste
water from the flue gas desulfurization
plant contains only a small quantity of
NH3. The NH3 values for the flue dust
must be monitored carefully, since they
may result in special stipulations being
made for operation of the DeNOx plant.
The maintenance effort for the opera-
tional measuring equipment required for
the DeNOx plant is relatively high.
VKR Full-Scale SCR Experience
on Hard Coal Fired Boilers
Klaus Goldschmidt
VEBA Kraftwerke Ruhr (VKR) operates
power plants in Northrine-Westfalia of the
Federal Republic of Germany with a total
capacity of 5500 MW gross. Most of the
boilers are fired with high ballast hard
coal. Older boilers have wet bottom
furnaces; newer ones are dry furnaces.
The great furnace ordinance of Germany
calls for a NOX emission rate 200 mg/m3
(i.e., 98 ppm), so all great boilers must be
retrofitted by DeNOx. Meanwhile, VKR
reduced NOX emissions from their boilers
by primary methods as far as possible.
Since the end of 1984, VKR handles up
to eight pilot plants to prove the SCR
technology. Since the end of 1985, 100%
of flue gas from district heating boiler
Buer (dry bottom, 150 MW), and since
mid-1986, sponsored by UBA, 50% of
flue gas from boiler Knepper C (molten
ash, 370 MW) is treated by SCR high
dust technology. Based on pilot-plant
tests, the paper describes both DeN
demonstration units, their operation, a
the findings.
Applicability of European SCR
Experience to U.S. Utility
Operation
J. Edward Cichanowicz and Georg<
R. Often
About 2200 MW of SCR capacity
operating or in start-up in Europe ai
February 1987. Five full-scale syst<
are currently operational in the Fed
Republic of Germany and two in Aus
Each unit has logged between 2000
6000 hours of operation. Experience I
these SCR installations will help d<
the cost and technical feasibility of
for potential U.S. application. This p
discusses the relevant experience a
pated from these and other Euroi
installations. Experience that will dir
apply to U.S. conditions is summai
as are topics which are not releva
U.S. application due to plant desigr
fuel limitations. The European
installations are first briefly surveyec
the significant design and oper
features reviewed. Relevant experiei
categorized into four topics: SCR c«
design, catalyst lifetime, process o
and plant integration. Finally, i
critical to the analysis of SCR tec
feasibility and cost for high sulfur
fired plants are summarized.
Comparison of Four Catalys
Used in Selective Catalytic
Reduction of NOX
Bo Herrlander
Tested catalysts all show a pseu
order reaction. High activity an
specific surface are beneficial
performance, even though high
surface also means smaller pit
higher pressure drop. The op
experiences are good, with no
activity deterioration.
The Improvement of
Injection Control System fo
Selective Catalytic NOX Re
System
K. Suyama
Mitsubishi Heavy Industries I
plied Selective Catalytic NOX
(SCR) systems for more than
-------
joth in Japan and abroad since it
ilivered the first SCR system for a
jiler in 1976. This paper describes the
:ontrol system of an SCR system devel-
>ped with a new concept to cope with the
ecent trend to operate a thermal power
)lant as a load swing operation unit and
s service results in a 600 MW boiler.
Development of Low Level NHs
/leasuring Method
'asuyuki Nakabayashi, Rikiya Abe,
nd Takusuke Izumi
Performance of NOX reducing catalysts
rill be continuously checked by meas-
ring slip NH3 downstream of the SCR
actor. There are two ways to measure
)w level NH3: one direct, and the other
idirect. The indirect method uses a
atalyst, the same kind we use to check
erformance, in order to convert NH3 to
0. EPOC and Anritsu Corporation
eveloped jointly the direct NH3 meas-
rement and applied it at Takehara #3
'00 MW) unit. This instrument detects
traviolet absorption of NH3 spectrum by
equency modulation. Sampling method
also important to measure low level
H3 (0-20 ppm) and is developed by us.
lis paper will describe the principle of
ese methods.
pdated Technical and
conomic Review of Selective
latalytic NOX Reduction
ystems
E. Damon, P. A. Ireland, and 0. V.
iovanni
Selective Catalytic NOX Reduction is
>w being used on coal-fired units in
pan, in both retrofit and new unit
plications. This update lists Japanese
ial-fired units using SCR. In addition, it
dates the technical design require-
ints to help prevent air heater plugging
1 ammonia-sulfur compounds. The
jor new requirement is a lower NH3
p limit of 3 - 5 ppm which in turn re-
ires significantly lower space veloc-
>s. Hence greater catalyst volumes and
>cess costs are realized than were
ntified 2 or 3 years ago. In addition,
> impact of the devaluation of the dollar
ainst the yen is reviewed. Current SCR
st analyses for both a new utility coal-
d unit application, and retrofit utility
l-fired units are provided. The new
ustrial NSPS NOX limits are presented,
1 an SCR cost analysis on a small
ustrial generator is reviewed. Finally,
conclusions based on Japanese SCR
experience in terms of updated costs and
its present applicability to U.S. coal-fired
units are presented.
Session Vb: Fundamental
Combustion Studies
Mechanisms of Fixed Nitrogen
Reduction in Pulverized Coal
Flames
John C. Kramlich, Thomas W. Lester,
and Jost O. L. Wendt
Although the major features that mark
the conversion of coal nitrogen have
been identified through extensive re-
search, some portions of the process are
not well understood. An understanding of
these processes, and their associated
rates, will provide the information needed
to develop process models. Three areas
have been identified for which present
process models fail to predict the
observed fixed nitrogen reduction: (1) the
reduction in nitrogen that occurs at very
short time, including devolatilization and
reaction in the immediate vicinity of the
coal particle; (2) nitrogen reduction in the
bulk fuel-rich regions that are charac-
teristic of staged combustion and reburn-
ing applications; and (3) fixed nitrogen
reduction at the final leaning-out point.
The work reported here examines these
problems through tasks on: homog-
eneous kinetics, NO reduction by hetero-
geneous media, and the overall process
of fixed nitrogen reduction in direct coal
combustion.
The Interplay Between Chemistry
and Fluid Mechanics in the
Oxidation of Fuel Nitrogen from
Pulverized Coal
Charles Kruger, Greg Haussmann,
and Steve Krewson
The evolution and subsequent reaction
of gas-phase nitrogenous species from
pulverized Montana Rosebud subbitumin-
ous coal have been measured in the
Stanford entrained-flow reactor under uni-
form and well controlled conditions.
Experiments have been performed at
atmospheric pressure with temperature
up to 1850 K and oxygen concentrations
varying from zero to 15.0 %. Gas-phase
measurements have been made of
carbon oxides, light hydrocarbons, NO,
NO2, N20, NH3, and HCN. Chemical and
physical analyses of party reacted coal
particles provide data on the carbon and
nitrogen content, porosity, and the rate of
tar pyrolysis. A major focus of this
research has been the role of tar in the
evolution of fuel nitrogen. At high heating
rates, substantial quantities of tar are
evolved in very short reaction times, and
the pyrolysis products are rich in
nitrogen. The rate of reaction of these
products in and around a volatile cloud
surrounding the parent coal particle
controls the oxidation of fuel nitrogen.
The measurements show that, when the
pyrolyzing coal particles are exposed to
oxygen concentrations as low as 4%, a
significant portion of the fuel nitrogen can
be oxidized to NO, although some of this
NO is subsequently reduced in the gas
phase.
Reduction of NOX by Fuel
Staging
Majed A. Toqan, J. Derek Teare,
Janos M. Beer, Leslie J. Radak, and
Alexander Weir, Jr.
Results are reported of theoretical and
experimental studies in which natural gas
was used as "reburn" fuel for NOX reduc-
tion in a No. 6 fuel oil flame. A Sandia
chemical kinetic code with kinetic para-
meters of hydrocarbon/NO reactions,
developed by J.M. Levy and B.R. Taylor
at MIT, was used to predict chemical
species concentrations in the "reburn"
zone as a function of residence time,
initial NO concentration, gas temperature,
and fuel equivalence ratio (0). The
fractional reduction of high initial NO con-
centrations^ 800 ppm) in the reburn stage
is shown to be proportional to the con-
centrations of CH, and NHj species. At
high temperatures (2000 K), the
abundance of CH, and NH, species
causes a reduction of NO from 800 to 46
ppm at a 0 of 1.3. At lower initial NO
concentrations (~ 40 ppm), NO formation
dominates over its reduction, with the
result that better reduction of NO is
achieved at the lower temperature of
1800 K: for an initial 25 and 38 ppm at
1800 and 2000 K, respectively. For a
given gas temperature the CHj radical
concentration increases with increasing
fuel equivalence ratio in the "reburn"
zone, and the fractional conversion of NO
to N2 as a function of 0 follows the usual
trend of showing an optimum at around
0 = 1.3. At lower than optimal fuel
equivalence ratios the NO reduction
becomes strongly temperature depend-
ent. (At 0 = 1.1 calculated NO reduc-
-------
tions are 18% at 1780 K and 60% at
2000 K.) Experimental data obtained in a
1.5 MW No. 6 oil flame with 400 ppm
(doped) initial NO concentration and at 0
= 1.1 showed good agreement with
predictions.
Fuel Bound Nitrogen Evolution
During the Devolatilization and
Pyrolysis of Coals of Varying
Rank
J. D. Freihaut, W. M. Prosica, and D.
J. Seery
The near-term use of coal for power
generation involves the development of
low NOX burners for retrofit applications
or the design of new boiler systems.
Intermediate and long-term applications
propose using dry or slurried micronized
coal feeds in modular, load-following
high-intensity combustion systems. All
systems anticipate a form of stoichio-
metric staging of the micro-scale com-
bustion process to obtain acceptable
levels of NOX emissions. However, maxi-
mizing carbon burnout while minimizing
NOX formation in these systems will
require the formulation of quantitative
models of the micro-scale combustion
process of coals of varying rank char-
acteristics. The complexity of the proces-
ses involved will necessitate models
more empirical and phenomenological
than mechanistic, but will need to take
into account the significant variation in
nitrogen evolution pathways with coal
type. This paper reports results of an
investigation of the nitrogen evolution
behavior of a range of coal ranks in a
variety of heating conditions and the
initial formulation of a kinetic model of
coal nitrogen devolatilization. With
respect to the total mass fraction of coal
nitrogen volatilized during transient heat-
ing of particles to 1000°C, the evolution
of fuel bound nitrogen appears relatively
rank-insensitive in moderate heating rate
conditions for high volatile bituminous
coals and lower ranks. The mass fraction
of nitrogen evolved follows the mass
fraction of coal volatilized and, under
conditions where secondary reactions of
tar are minimized, the distribution of
parent coal nitrogen between tar and light
gases follows the distribution of parent
coal mass between these volatile types.
The distribution of coal nitrogen in volatile
types varies as the distribution of coal
mass between the volatile types. For
medium volatile and higher rank coals,
the mass fraction of nitrogen evolved
during particle heating to 1000°C varies
as the volatility of parent coal and is
therefore rank sensitive. However, in
moderate heating rate conditions, the
distribution of parent coal nitrogen
between volatile types continues to follow
the distribution of parent coal mass
between these types. The susceptibility
of devolatilization-produced tar species to
secondary pyrolysis reactions varies
significantly with coal rank character-
istics. Secondary reactions of tar occur
within the devolatilizing particle, in the
boundary layer around the particle, and
the free stream. High temperature
secondary pyrolysis reactions of tars
occurring in fuel rich conditions result in
the release of tar-bound nitrogen to the
light gas component of the volatile yield,
primarily in the form of HCN. The high
temperature secondary reaction network
leading to the production of cyanide spe-
cies also produces acetylene, ethylene,
and carbon monoxide and appears to
commence the onset of soot production.
The secondary reaction network for tars
commences at particle or gas temper-
atures of 900°C with a strong temper-
ature and coal rank dependence. The
formation of light gas nitrogen species,
NOX precursors, is strongly rank-depen-
dent because the temperature sensitivity
of secondary reactions of the heavy
hydrocarbons formed at relatively low
particle temperatures, 300-600°C, varies
with the mix of hydrocarbon species
present in the parent coal; i.e., the rank
characteristics of parent coal. Progress in
the formulation of a rank-dependent
model of nitrogen evolution is discussed.
Session VI: Cyclone-Fired
Boilers
Feasibility of Reburning for
Cyclone Boiler NOX Control
G. J. Maringo, M. A. Acree, H.
Farzan, and M. W. McElroy
This paper gives results of an engi-
neering and economic feasibility study of
reburning as a potential retrofit NOX
reduction method for coal-fired cyclone
boilers. Results indicate that most
cyclone boilers are suitable for retrofit
from the standpoint of available furnace
residence time, a key parameter in apply-
ing the technology. Heat transfer analysis
for a 200 MW cyclone boiler case study
predicts insignificant increases in furnace
exit gas temperatures; thus, no conve
tive pass or sootblowlng modificatio
would be required. No technical fact<
were identified that would preclu
retrofit of reburning to most of t
cyclone boiler generating capacity. N
reductions predicted for 200 and 700 to
boilers were 50 and 60%, respective
without derating. These predictions
based on the units' available furn;
residence times. Capital and 10-y
levelized busbar power cost estims
ranged from $15 to $34/kW and 1.6 to
mills/kWh, depending on the reburr
fuel selected. A follow-on pilot reburr
project on a 6 x 106 Btu/hr cycle
equipped test furnace is also describe
NOX Control Options for Coal-
Fired Cyclone Utility Boilers
R. E. Thompson, R. M. Himes, an
G. R. Often
The implementation of stringent
regulations in Japan and West Gerr
has increased the probability of
control provisions in acid rain legisl
in the U.S. The economic impact o
proposed legislation is a serious coi
to utilities with cyclone units bee
they have high NOX emissions and
few cost-effective retrofit options.
paper highlights an EPRI study dir
at evaluating NOX control options ra
from conventional and advanced
bustion modifications to Iow-N0x sla
combustors, reburn technology, an
gas treatment. The first phase c
study included a review of cyclom
emission characteristics, their d
dence on boiler design and op«
parameters, and a comparison to
unit designs. Prior attempts to redt
clone NOX emissions by means o
bustion modifications were eva
and constraints to Iow-N0x opi
identified. These design and op
constraints included reduced com
gas temperature, slag capture ai
cosity control, high temperatur
rosion, and carbon burnout. The
NOX reduction potential and op
constraints of several potential
NOX control concepts were thei
pared on a preliminary basis to de
which concepts exhibited th<
promise. A more detailed evalu
these concepts in continuing, ii
brief technical and economii
parisons to alternative NOX cor
tions for cyclone units.
-------
TRW Coal Combustor-NOx
Emissions
Donald J. Frey
TRW has developed an atmospheric,
entrained-coal combustor with significant
support from DOE/PETC which can either
be retrofitted to existing units or
integrated with new steam generating
equipment. The concept consists of a
water-cooled main combustor in which
pulverized coal is burned in suspension
at heat release rates approaching 106
Btu/hr-ft3 of combustor volume. Com-
bustion occurs at sub-stoichiometric con-
ditions in order to control NOX formation.
More than 90% of the ash is removed
from the combustors as molten slag. The
flue gas exiting the combustor is at a
temperature near 1650°C, contains
almost no carbon, only 10% of the ash,
and CO and H2 (amounting to about 15%
of the original heat input). These gaseous
combustibles must be burned in the host
boiler, and the final air, termed secondary
air, is injected into the furnace through a
conventional windbox/burner arrange-
ment. TRW has conducted many tests at
its Capistrano test facilities to minimize
NOX formation. The earlier determinations
were made on a 10 x 10e Btu/hr com-
bustor, firing Utah, Wyoming, and
Montana coals. The secondary air was
admitted through fixed pipes, and final
combustion occurred in an uninsulated
water-cooled chamber. Later tests were
performed in a 50 x 106 Btu/hr com-
bustor, also at Capistrano. These results
supported most of the earlier conclusions
and provided additional insight regarding
the beneficial effects on NOX formation of
controlled mixing and burning in the
secondary combustion stage.
Session Vila: OH- and Gas-Fired
Boilers
Methanol Dual-Fuel Combustion
Alexander Weir, Jr., Leslie J. Radak,
Edward A. Danko, Ray A. Lewis, and
Harry W. Buchanan
Dual-fuel combustion is a technique
invented to lower emissions of NOX from
boilers. This paper presents experimental
data using this technique in a utility boiler
at a level of 35 MW. Tests with low sulfur
(0.21% S) oil/natural gas, low sulfur oil/
methanol, and natural gas/methanol were
performed, and the NOX emission data
were compared with NOX emissions of
100% low sulfur oil, gas, and methanol.
Tests with a mixture of 70% natural
gas/30% methanol revealed that the NOX
emissions level using the dual-fuel
technique was lower than those obtained
with either 100% gas or 100% methanol.
The NOX level was about 25% of the level
obtained with natural gas fired in a
conventional combustion mode or about
50% of the NOX level obtained with
natural gas fired in a "staged" combus-
tion or "burners-out-of-service" mode, a
state-of-the-art combustion modification
technique used to lower NOX emissions.
Application of Fuel Biasing for
NOX Emission Reductions in
Gas-Fired Utility Boiler
Greg C. Quartucy, M. N. Mansour,
and James N. Nylander
The effectiveness of fuel biasing in
reducing NOX emissions from gas-fired
utility boilers has been evaluated by the
San Diego Gas & Electric Company
(SDG&E). The unit chosen for this eval-
uation, South Bay Unit 1, is a 150 MW
face-fired unit which currently meets local
NOX emissions limits by operating with
burners-out-of-service (BOOS). This
operating mode results in CO emissions
of greater than 2000 ppm and an O2
imbalance. Fuel biasing offers a reduction
in NOX emission by controlling com-
bustion stoichiometry in two discrete
combustion stages: the first operated
fuel-rich to limit the formation of thermal
NOX; and the second operated fuel-rich or
fuel-lean. The primary advantage of fuel
biasing is that it provides better control of
combustion stoichiometry, which reduces
02 imbalances and increased CO emis-
sions which may accompany BOOS
operation. The effect of fuel bias ratio, air
register position, and excess oxygen
level on unit emissions and performance
was evaluated. The use of fuel biasing
allowed the unit to meet local NOX
regulations, while decreasing the 02 im-
balance and reducing CO emissions to
less than 500 ppm. Additionally, improve-
ments in unit operating efficiency were
measured when using the fuel biasing
firing mode.
NOX Inventory and Retrofit
Assessment
Dominick J. Mormile, Stephen E.
Kerho, Skillman C. Hunter, and Peter
E. Coffey
The Empire State Electric Energy Re-
search Corp. (ESEERCO) has funded a
program to develop a model for
estimating NOX emissions from the New
York Power Pool (NYPP) electric system
for different generation dispatch scenar-
ios. Baseline emission levels for each
boiler and for the entire system were
calculated. In addition, the technical
feasibility, NOX reduction potential, and
cost of commercially available NOX con-
trol technologies were evaluated for each
boiler. Besides quantifying annual NOX
emission rates for NYPP fossil-fuel-fired
power plants, the model enables
ESEERCO to evaluate the effectiveness
and costs of alternative NOX reduction
strategies.
Full Scale Evaluation of Urea
Injection for NO Removal
M. N. Mansour, Sam N. Nahas, Greg
C. Quartucy, James N. Nylander,
Harold A. Kerry, Les J. Radak, David
Eskinazi, and T. S. Behrens
An engineering evaluation was per-
formed by San Diego Gas and Electric
(SDG&E) to assess the use of urea
injection for NO emissions control on
gas- and oil-fired utility boilers. This
evaluation consisted of a field assess-
ment of the technology on Unit 2 at
SDG&E Encina Generating Station and
an evaluation of technology economics.
The program was co-funded by Southern
California Edison Company (SCE) and
the Electric Power Research Institute
(EPRI). Fuel Tech, Inc. (FT) co-spon-
sored the field assessment. The program
represented the first application of urea
technology to a utility boiler. Urea in-
jection for NO emissions control was
developed in 1976 by KVB under EPRI
sponsorship. It involves spraying urea as
an aqueous solution into the products of
combustion where the urea reacts with
NO in the gas phase to produce molec-
ular nitrogen and water. The process de-
pends on combustion gas temperature
with a reduction in emissions achieved
between 760 and 1090°C. The results of
the field assessment showed that urea is
effective in reducing NO emissions from
natural-gas- and fuel-oil-fired utility
boilers. NO removals ranged from 30 to
70%. Variables identified as influencing
the performance of the process included
the urea to NO mole ratio, injection
variable, initial NO concentration, and
urea solution concentration. The
economic assessment has shown that the
cost of urea injection is sensitive to the
level of NO removal achieved, plant size,
and plant capacity factor. The total
-------
levelized costs for the process were
estimated based on the performance of
the system currently undergoing evalu-
ation. The cost of the technology was
estimated for plants ranging from 100 to
500 MW in size and operating over a
broad range of initial NO concentrations.
For the case studied, the levelized cost of
the technology ranged from $700 to
$3500/ton of NO removed with the lower
cost obtained from the largest plant oper-
ating at high initial NO (600 ppm @ 3%
02). Future work includes optimizing the
performance of the urea injection system
to improve reagent utilization and level of
NO removal achieved. Future work will
also define the control logic for a fully
automated urea injection system as well
as establish the effects on boiler opera-
tion of long-term urea injection.
Retrofit Combustion Controls for
Gas/Oil-Fired Utility Boilers
Wesley W. Pepper, Ronald F. Balingit,
Dan V. Giovanni, and Donald P.
Teixeira
The NOX Reduction Program, a
voluntary undertaking by the City of Los
Angeles, Department of Water and Power
(LADWP), was initiated after determining
that utility boilers in the Los Angeles
Basin are becoming targets for additional
NOX controls and that Rule 1135.1 NOX
settlement limits may be exceeded in the
future under certain dispatch and fuel use
scenarios. The program is based on two
objectives: (1) to implement measures
that will ensure continued compliance
with the Rule 1135.1 NOX settlement
emission limits, which could be exceeded
in the 1990s under certain resource
scenarios such as unavailability of natural
gas or hydroelectric import energy; and
(2) to evaluate advanced Iow-N0x com-
bustion technology capabilities systems
as an alternative to postcombustion treat-
ment for retrofit on existing low capacity
factor utility boilers. Combustion controls
appear to be significantly more cost ef-
fective than postcombustion treatment,
and their installation could be incorpora-
ted with other compatible boiler modi-
fications that would improve boiler
reliability and thermal performance. The
LADWP NOX Reduction Program is
designed to accomplish these overall
objectives through a three-phase ap-
proach: Phase 1 was an engineering
evaluation of advanced combustion NOX
control techniques applicable to LADWP
oil/gas-fired boilers; Phase 2 involves the
design, fabrication, and installation of a
low-NOx demonstration system on one
LADWP boiler; and Phase 3 will be the
test, evaluation, and demonstration of the
installed Iow-N0x technology. Tasks
performed to accomplish the Phase 1
objective were: (1) to identify and screen
applicable NOX control alternatives; (2) to
assess commercial experience with ad-
vanced low-NOx combustion technology
in Japan; (3) to solicit preliminary
technical/budgetary proposals from Bab-
cock & Wilcox (B&W) and Combustion
Engineering (C-E) which provide esti-
mates of NOX emissions control capabil-
ities for the LADWP units; (4) to analyze
the information from Japanese installa-
tions and the boiler manufacturer's
proposals; and (5) to select a boiler and
NOX control technology for consideration
in Phase 2. The work was performed
jointly by LADWP and its consultants,
Electric Power Technologies (EPT) and
Electric Power Services International, Inc.
This paper summarizes the results of
Phase 1 and plans for Phases 2 and 3.
Session Vllb: Industrial and
Commercial Applications
Pilot-Scale Tests of a
Multistaged Burner Designed for
Low NOX Emission and High
Combustion Efficiency
James A. Mulholland and R. K.
Srivastava
A multistaged combustion burner de-
sign is being evaluated on a 0.6 MW
package boiler simulator for in-furnace
NOX control and high combustion
efficiency. An adiabatic precombustion
chamber burner has been reduced in size
by about a factor of two. Natural gas,
doped with ammonia to yield a 5.8% fuel
nitrogen content, was used to simulate a
high nitrogen content fuel/waste mixture.
A burner baseline NO emission of 315
ppm (measured dry, corrected to 0% 02)
was measured, compared with an
emission of over 1000 ppm estimated for
a conventional, unstaged burner. Both
deep air staging, resulting in a three-
stage configuration, and fuel staging with
undoped natural gas, yielding four
stoichiometric zones, reduced the
baseline NO emission by about 50% (to
160 ppm), meeting the program goal.
However, deep air staging resulted in the
entire front end of the broiler being fuel-
rich and required penetrations into the
boiler for staged air injection. Fuel
staging, on the other hand, required no
boiler penetrations (staged fuel and air
were injected from the boiler front wall)
and only a small fuel-rich flame core in
the boiler (produced aerodynamically).
Furthermore, sufficient air for complete
oxidation of the primary combustion
products was provided at the burner exit
(prior to staged fuel and air injection into
the boiler) in the fuel staging tests. Thus
the four-stage configuration appears to
be the most promising approach for
minimizing NO emissions and
maximizing primary fuel/waste
destruction. Further testing is ongoing
with pyridine and fuel oil mixtures to
better characterize surrogate fuel/waste
destruction efficiency.
Diesel Engine NOX Control:
Selective Catalytic Reduction
and Methanol Emulsion
John H. Wasser and Richard B. Perry
EPA's Air and Energy Engineering Re
search Laboratory has recently con
ducted two diesel engine NOX reductioi
studies: one a long term evaluation of <
selective catalytic reduction (SCR) sys
tern, and the other an evaluation c
methanol emulsion fuel. The SCR projec
established the NOX reductio
performance of a catalytic unit over
4000-hour period. NOX reductions range
between 98 and 69% during the test, wil
periodic (approximately every 130
hours) dry cleaning required to mainta
activity. Measurements of other pollutan
(CO and particulate matter) indicated th
the catalyst and/or ammonia addition hi
no effect on these emissions. No advert
operational problems were encounter
on the engine system during the te
program. The methanol proje
established the performance of this fi
modification. The diesel system w
equipped with a fuel emulsification u
capable of delivering methanol/fuel-oil
water/fuel-oil mixtures to the engine's fi
supply line. NOX emission reductions
20-25% were measured when firi
methanol/fuel-oil emulsions compared
fuel-oil firing only. However, substar
increases in CO (from 30 to 70 ppm) i
hydrocarbon (from 4 to 200 ppm) en
sions were also recorded. The metti
ol/oil emulsion results are also compa
to water/oil emulsion results on the s<
engine.
10
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The Control of NOX Emissions
From Municipal Solid Waste
Incinerators
M. P. Heap, W. S. Lanier, and W. R.
Disposal of municipal solid waste is a
growing problem because of the
declining capacity of landfills and
restrictions on their use. Incineration
provides a cost effective solution: the
bulk of material requiring landfilling is
reduced, the material can be landfilled
with minimal restrictions, and the energy
in the waste is converted to usable heat
and/or power. Incineration cannot be
accomplished without due consideration
to the generation and control of atmos-
pheric pollutants. Of major concern are
trace quantities of potentially toxic
hydrocarbons. The emission of these
species can be minimized by appropriate
design and operation of the combustion
systems; unfortunately, these measures
tend to increase rather than decrease
emissions of NOX. This paper discusses
the types of municipal waste combustion
devices and the types of pollutants
generated during waste combustion. Four
methods of NOX control are discussed:
Combustion Zone Control, Selective Non-
Catalytic, Selective Catalytic, and Hybrid
Processes.
Nitrogen Oxide Emissions
Reduced from Cement Kiln
Exhaust Gases by Process
Modification
M. S. May, R. MacMann, J. C.
Phillips, and G. L. Young
In January 1982 the South Coast Air
Quality Management District (SCAQMD),
El Monte, CA, adopted a rule to reduce
emissions of NOX from the exhaust gases
of pqrtlant cement kilns in the South
Coast Air Basin. The rule was drafted to
allow cement manufacturers to demon-
strate through research whether or not
NOX could be reduced by modification of
the cement manufacturing process.
Riverside Cement Company, as a result
of review of the literature and pilot
studies conducted by KVB, Inc.,
selected the following four tactics as
having potential for reducing NOX
emissions: (1) reduce the quantity of fuel
used per ton of clinker; (2) reduce the
quantity and temperature of the primary
air; (3) control the configuration of the
flame; and (4) improve control of the
operation of the kiln. The Riverside
Cement Company was able to demon-
strate with statistical confidence that the
NOX emissions, after the implementation
of the four tactics for the cement manu-
facturing process, were 26% less than
the premodification emissions.
NOX Formation in a Cement Kiln:
Regression Analysis
John M. Groom, Mallory S. May,
Gerald L. Young, Craig Phillips, and
Russ MacMann
NOX emissions from a cement kiln
were analyzed with step-wise linear
regression. The goal was to demonstrate
which operating variable(s) control the
rate of NOX emissions. Of 14 independent
variables in the regression analysis, burn-
ing zone temperature of the kiln was the
only significant variable; it accounted for
83% of the variability in NOX emissions.
Because the burning zone required for
production of acceptable quality clinker
averages between 1300 and 1400°C,
minimum NOX emission from a long, dry
cement kiln is probably 5-6 Ib NO,/ton of
clinker produced.
Authors' Addresses
Authors' addresses appear below
alphabetically, rather than with their indi-
vidual abstracts.
Rikiya Abe, Research and Engineering
Office, Thermal Power Dept., Electric
Power Development Co., Ltd., Tokyo,
100, Japan.
Michael A. Acree, Domestic Fossil Oper-
ations, Babcock and Wilcox, Barberton,
OH 44203.
Rui F. Afonso, Group Manager, Dynatech
Scientific, 99 Erie St., Cambridge, MA
02139.
J. W. Allen, NEI International Combus-
tion, Ltd., Sinfin Lane, Derby, DE2 9GJ,
United Kingdom.
M. Araoka, Boiler Engineering Dept.,
Power Systems Engineering Div.,
Power Systems Hq., Mitsubishi Heavy
Industries, Ltd., Shin-tamachi Bldg. 34-
6, Shiba 5-Chome, Minato-ku, Tokyo,
108, Japan.
Richard E. Ayers, Senior Attorney, Na-
tural Resources Defense Council, 1350
New York Ave., N.W., Washington, DC
20005.
Shigeru Azuhata, Senior Researcher,
Coal Technology Center, Hitachi Re-
search Laboratory, Hitachi, Ltd., Ibaragi,
319-12, Japan.
Ronald F. Balingit, Dept. of Water and
Power, City of Los Angeles, Los
Angeles, CA 90012.
W. Bartok, Energy and Environmental
Research Corp., Irvine, CA 92718.
Janos M. Beer, Dept. of Chemical Engin-
eering and the Energy Laboratory,
Massachusetts Institute of Technology,
Cambridge, MA 02139.
T. S. Behrens, Fuel Tech, Inc., 61 Taylor
Reed Place, Stamford, CT 06906.
S. J. Bortz, KVB, Inc., 18006 Skypark
Blvd., Irvine, CA 92714.
W. J. D. Brooks, Generation Development
and Construction Div., Central Electri-
city Generating Board, Barnett Way,
Barnwood, Gloucester, GL4 7RS,
United Kingdom.
Robert I. Bruck, Associate Professor of
Plant Pathology and Forestry, North
Carolina State Univ., Raleigh, NC
27695-7616.
Harry W. Buchanan, Celanese Corp.,
New York, NY 10036.
N. A. Burdett, Technology Planning and
Research Div., Marchwood Engineering
Laboratories, Central Electricity Gener-
ating Board, Marchwood, Southhamp-
ton, S04 4ZB, United Kingdom.
S. L. Chen, Energy and Environmental
Research Corp., 18 Mason, Irvine, CA
92718.
J. Edward Cichanowicz, Project Manager,
Integrated Environmental Control, Elec-
tric Power Research Institute, Palo Alto,
CA 94303.
Paul L. Cioffi, Domestic Fuel Operations,
Babcock and Wilcox, Barberton, OH
44203.
M. J. Clark, Domestic Fuel Operations,
Babcock and Wilcox, Barberton, OH
44203.
F. Clarke, Central Electricity Generating
Board, OED, Midlands Area, Ratcliffe-
on-Soar, Nottinghamshire, NG11 OEE,
United Kingdom.
Peter E. Coffey, New York Power Pool,
3890 Carman Rd., Schenectady, NY
12303.
M. B. Cohen, Fossil Power Systems,
Combustion Engineering, Inc., Windsor,
CT 06095.
John M. Groom, Quantitative Applica-
tions, Inc., 3898 West Wood Path, Stone
Mountain, GA 30083.
J. E. Damon, Stearns-Roger Div. of
United Engineers and Constructors,
Denver, CO 80217.
Edward A. Danko, Southern California
Edison Co., Rosemead, CA 91770.
11
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G. C. Ousatko, Energy Systems Associ-
ates, Tustin, CA 92680.
David Eskinazi, Electric Power Research
Institute, 3412 Hillview Ave., Palo Alto,
CA 94303.
H. Farzan, Research and Development
Div., Babcock and Wilcox, Alliance, OH
44601.
Timothy Flora, Ohio Edison Co., Lorain,
OH 44052.
G. Foley, Central Electricity Generating
Board, Fiddler's Ferry Power Station,
Widnes Rd., Cuerdley, Warrington,
WAS 2UT, United Kingdom.
B. A. Folsom, Energy and Environmental
Research Corp., Irvine, CA 92718.
J. D. Freihaut, United Technologies Re-
search Center, E. Hartford, CT 06108.
Donald J. Frey, TRW, Inc., Redondo
Beach, CA 90278.
Dan V. Giovanni, Electric Power Techno-
logy, Inc., Berkeley, CA 94705.
Klaus Goldschmidt, VEBA Kraftwerke
Ruhr AG, D 4650 Gelsenkirchen,
Federal Republic of Germany.
Charles Hakkarinen, Electric Power
Research Institute, 3412 Hillview Ave.,
Palo Alto, CA 94303.
Greg Haussmann, Dept. of Mechanical
Engineering, Stanford Univ., Stanford,
CA 94305.
M. P. Heap, Energy and Environmental
Research Corp., 18 Mason, Irvine, CA
92718.
T. D. Hellewell, Fossil Power Systems,
Combustion Engineering, Inc., Windsor,
CT 06095.
Bo Herrlander, Flakt Industri AB, Vaxjo,
Sweden.
R. M. Himes, Fossil Energy Research
Corp., Laguna Hills, CA 92653.
Skillman C. Hunter, KVB, Inc., 18006
Skypark Blvd., Irvine, CA 92714.
Hiroshige Ikebe, Boilers Research and
Development Dept., Boiler Plant Div.,
Ishikawajima Harima Heavy Industries
Co., Ltd., 3-13, 5-Chome, Toyo, Koto-
ku, Tokyo, 135, Japan.
P. A. Ireland, Steams-Roger Div. of
United Engineers and Constructors,
Denver, CO 80217.
A. Iwanage, Manager, No. 2 Land Boiler
Designing Section, Nagasaki Shipyard
and Engine Works, Mitsubishi Heavy
Industries, Ltd., 1-1, Akuno-oura-machi,
Nagasaki, Japan.
Takusuke Izumi, Engineering Dept.,
Industrial Automation Div., Anritsu
Corp., Tokyo, 106, Japan.
Stephen A. Johnson, Physical Sciences,
Inc., P.O. Box 3100, Andover, MA
01810.
Stephen E. Kercho, Electric Power Tech-
nologies, Inc., P.O. Box 5560, Berkeley,
CA 94750.
Harold A. Kerry, Southern California
Edison Co, 2244 Walnut Grove Ave.,
Rosemeade, CA 91770.
Takashi Kiga, Boilers Research and De-
velopment Dept., Boiler Plant Div.,
Ishikawajima Harima Heavy Industries
Co., Ltd., 3-13, 5-Chrome, Toyo, Koto-
ku, Tokyo, 135, Japan.
Fumio Koda, Deputy Manager, Thermal
Power Design Dept., Babcock-Hitachi,
K. K. Kure, Hiroshima, 737, Japan.
A. Kokkinos, Fossil Power Systems,
Combustion Engineering, Inc., Windsor,
CT 06095.
John C. Kramlich, Energy and Environ-
mental Research Corp., 18 Mason,
Irvine, CA 92718.
Steve Krewson, Dept. of Mechanical
Engineering, Stanford Univ., Stanford,
CA 94305.
Charles Kruger, Dept. of Mechnical Engi-
neering, Stanford Univ., Stanford, CA
94305.
F. R. Kurzynske, Gas Research Institute,
Chicago, IL 60631.
W. Steven Lanier, Energy and Environ-
mental Research Corp., 18 Mason,
Irvine, CA 92718.
Albert D. LaRue, Domestic Fuel Oper-
ations, Babcock and Wilcox, Barberton,
OH 44203.
R. Leibfritz, Institute of Industrial Produc-
tion, Univ. of Karlsruhe, Hertzstrasse 16,
7500 Karlsruhe 21, Federal Republic of
Germany.
Thomas W. Lester, Dept. of Mechanical
Engineering, Louisiana State Univ.,
Baton Rouge, LA 70803.
Ray A. Lewis, Celanese Chemical Co.,
Inc., Dallas, TX 75247.
R. D. Lewis, Fossil Power Systems, Com-
bustion Engineering, Inc., Windsor, CT
06095.
A. D. Liang, Research and Development,
Babcock and Wilcox, Alliance, OH
44601.
Robert A. Lisauskas, Riley Stoker Corp.,
P.O. Box 547, Worcester, MA 01613.
Russ MacMann, Gifford-Hill and Co., Inc.,
300 E. John W. Carpenter Freeway,
Irving, TX 75062.
Keiji Makmo, Boilers Research and
Development Dept., Boiler Plant Div.,
Ishikawajima Harima Heavy Industries
Co., Ltd., 3-13, 5-Chome, Toyo, Koto-
ku, Tokyo, 135, Japan.
M. N. Mansour, Applied Utility Systems,
Inc., 1720 E. Garry Ave., Suite 221,
Santa Ana, CA 92705.
G. J. Maringo, Domestic Fossil Opera-
tions, Babcock and Wilcox, Barberton,
OH 44203.
Tadahisa Masai, Senior Engineer, Com-
bustion Systems, Thermal Power De-
sign Dept., Babcock-Hitachi, K.K. Kure,
Hiroshima, 737, Japan.
Charles C. Masser, U.S. Environmental
Protection Agency, Air and Energy
Engineering Research Laboratory,
Research Triangle Park, NC 27711.
Mallory S. May, Professional Services
and Management, 703 McKinney Ave.
Suite 302, Dallas, TX 75202.
J. M. McCarthy, Energy and Environmen
tal Research Corp., 18 Mason, Irvine
CA 92718.
M. S. McCartney, Fossil Power Systems
Combustion Engineering, Inc.
Windsor, CT 06095.
M. W. McElroy, Air Quality Control, Elec
trie Power Research Institute, Palo Alt<
CA 94303.
R. W. McGraw, Pennsylvania Electr
Co., Johnstown, PA 16907.
Claire E. McHale, Riley Stoker Corf
P.O. Box 547, Worcester, MA 01613.
R. McMillan, Foster Wheeler Deve
opment Corp., 12 Peachtree Re
Livingston, NJ 07039.
Shigehiro Miyamae, Boilers Resear
and Development Dept., Boiler Pie
Div., Ishikawajima Harima Hea
Industries Co., Ltd., 3-13, 5-Chorr
Toyo, Koto-ku, Tokyo, 135, Japan.
Shigeki Morita, Leader Engine<
Combustion Systems, Thermal Pov
Design Dept., Babcock-Hitachi, K
Kure, Hiroshima, 737, Japan.
Dominick J. Mormile, Consolidal
Edison Co. of New York, Inc., 4 Irv
Place, New York, NY 10003.
James A. Mulholland, U.S. Environme
Protection Agency, Air and Ene
Engineering Research Laboratory,
search Triangle Park, NC 27711.
Sam N. Nahas, Applied Utility Syste
Inc., 1720 E. Garry Ave., Suite .'
Santa Ana, CA 92705.
Yasuyuki Nakabayashi, Research
Engineering Office, Thermal PC
Dept., Electric Power Development
Ltd., Tokyo, 100, Japan.
12
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Tsuneo Narita, Executive Managing
Director, Babcock-Hitachi, K. K., Tokyo,
Japan.
P. Meeker, Neckarwerke Elektrizitatsver-
sorgungs-AG, D-7300 Esslingen, West
Germany.
James N. Nylander, San Diego Gas and
Electric Co., 114 10th Ave., San Diego,
CA 92112.
George R. Often, Project Manager, Air
Quality Control, Electric Power
Research Institute, Palo Alto, CA
94303.
P. C. Orban, Pennsylvania Electric Co.,
Johnstown, PA 16907.
Wesley W. Pepper, Dept. of Water and
Power, City of Los Angeles, Los
Angeles, CA 90012.
Richard B. Perry, U.S. Environmental
Protection Agency, Air and Energy
Engineering Research Laboratory,
Research Triangle Park, NC 27711.
David W. Pershing, Energy and Environ-
mental Research Corp., 18 Mason,
Irvine, CA 92718.
J. Craig Phillips, JCP Associates, Inc.,
4480 7th St., Riverside, CA 92501.
Wallace S. Pitts, III. Kilkelly Environ-
mental Associates, Raleigh, NC 27622.
J. H. Pohl, Energy Systems Associates,
Tustin, CA 92680.
W. M. Prosica, United Technologies
Research Center, E. Hartford, CT
06108.
Greg C. Quartucy, KVB, Inc., 18006
Skypark Blvd., Irvine, CA 92714.
Leslie J. Radak, Southern California
Edison Co., Rosemead, CA 91770.
O. Rentz, Institute for Industrial Produc-
tion, Univ. of Karlsruhe, Hertzstrasse
16, 7500 Karlsruhe 21, Federal
Republic of Germany.
Randall Rush, Southern Company
Services, Birmingham, AL 35202.
M. Sakai, Manager, Power Systems
Engineering Research and Promotion
Laboratory, Nagasaki Research and
Development Center, Mitsubishi Heavy
Industries, Ltd., 180 Koyakimachi
Nishisonogi-gun, Nagasaki, Japan.
Edmund S. Schindler, Supervisor, Emis-
sion Control Engineering, Foster
Wheeler Energy Corp., Livingston, NJ
07039.
W. R. Seeker, Energy, and Environmental
Research Corp., 18 Mason, Irvine, CA
92718.
D. J. Seery, United Technologies Re-
search Center, E. Hartford, CT 06108.
Jack S. Siegel, Deputy Assistant Secre-
tary for Coal Technology, U.S. Dept. of
Energy, Washington, DC 20545.
Lowell L. Smith, Energy Technology Con-
sultants, Irvine, CA 29715.
R. D. Snodgrass, Riley Stoker Corp., P.O.
Box 547, Worcester, MA 01613.
R. K. Srivastava, Acurex Corp., Durham,
NC 27713.
K. Suyama, Mitsubishi Heavy Industries,
America, Inc., c/o Combustion Engi-
neering, Inc., 1000 Prospect Hill Rd.,
Windsor, CT 06095.
J. Derek Teare, Dept. of Chemical
Engineering and the Energy Laboratory,
Massachusetts Institute of Technology,
Cambridge, MA 02139.
Donald P. Teixeira, Electric Power
Services International, Inc., Walnut
Creek, CA 94596.
R. E. Thompson, Fossil Energy Research
Corp., Laguna Hills, CA 92653.
Dennis A. Tirpak, U.S. Environmental
Protection Agency, Office of Policy,
Planning, and Evaluation (Office of
Policy Analysis), Washington, DC
20460.
Majed A. Toqan, Dept. of Chemical
Engineering and the Energy
Laboratory, Massachusetts Institute of
Technology, Cambridge, MA 02139.
Joel Vatsky, Director, Combustion and
Environmental Systems, Foster-Wheeler
Energy Corp., Livingston, NJ 07039.
John H. Wasser, U.S. Environmental
Protection Agency, Air and Energy
Engineering Research Laboratory,
Research Triangle Park, NC 27711.
Alexander Weir, Jr., Southern California
Edison Co., Rosemead, CA 91770.
Jost O. L. Wendt, Dept. of Chemical
Engineering, Univ. of Arizona, Tucson,
AZ 85721.
Gerald L. Young, St. Marys Peerless Ce-
ment Co., 9333 Dearborn St., Detroit,
Ml 48209.
B. B. Emmel is with Radian Corp., Research Triangle Park, NC 27709.
James D. Kllgroo is the EPA Project Officer (see below).
The complete report consists of two volumes, entitled "Proceedings: 1987 Joint
Symposium on Stationary Combustion NOX Control, New Orleans, LA, March
1987:"
'Volume 1," (Order No. PB 89-139 695/AS; Cost: $42.95)
'Volume 2." (Order No. PB 89-139 703/AS; Cost: $49.95)
The above reports will be available only from: (Costs subject to change)
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
13
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