United States
Environmental Protection
Agency
Industrial Environmental
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-84-078 July 1984
&ER& Project Summary
Oxides of Nitrogen/Ammonia
Control Technology for Oil Shale
Retort Emissions: Interim Report
David W. Dunn, Timothy A. Bonner, and Sam C. Cheng
Monsanto Research Corporation
(MRC) under EPA Contract No. 68-03-
3025 has studied the pollution potential
and control of nitrogen oxides/ammonia
(NOX/NH.) from oil shale retorting
operations. The primary objectives of
this study were to collect the available
data on NOX/NH, emissions from oil
shale retorting operations, define the
NOX/NH, pollution potential from oil
shale development on the surrounding
area, to determine available technology
to control these emissions, and to
design a mobile pilot plant for the most
promising control, (1,000 scfm) that
might later be built and used in the field
to establish the control effectiveness of
the selected technology. This interim
report estimates the ambient NOX con-
centrations resulting from five planned
developments in the Piceance Basin and
makes recommendations for NOX/NH]
control. Rationale for these recommen-
dations is also presented. The final
design phase of the project was to com-
mence upon approval of this selection.
The NOX emissions do not pose a
serious problem; therefore, it was decid-
ed that a pilot NOX control device for
research purposes would not be
designed.
This Project Summary was developed
by EPA's Industrial Environmental Re-
search Laboratory, Cincinnati, OH, 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
Interest in the recovery of oil from shale
has increased during the past decade as oil
production in the United States 4ias con-
tinued to fall behind domestic demand. Oil
shale development can assist the United
States in becoming less dependent on for-
eign oil. However, the development of the
vast oil shale deposits in the Western states
is not without risks. The developers must not
only design and optimize new processes but
must also be aware of potential environ-
mental changes in the near-pristine areas
where shale is found. To help reduce en-
vironmental effects in these areas, the U.S.
Environmental Protection Agency (EPA) is
currently evaluating alternate control tech-
nologies for several potential pollutants,
among them, nitrogen oxides/ammonia
(NOX/N03).
Summary
The VALLEY air dispersion model was us-
ed to predict qualitatively the NOX pollution
potential from five selected oil shale
developments currently being planned. The
NOX contributions from these facilities were
added to the median background concentra-
tion of 9 fjg/m3 and the total was found to
be within the National Ambient Air Quality
Standard (NAAQS) of 100 n9/m3, except for
isolated points. Most developments have a
small area surrounding the plant site where
the NOX concentration exceeds 50 ng/m3,
but this level drops rapidly as the distance
from the plant increases. In most instances,
the concentration drops below 5 jig/m3
above ambient at a distance of 6 km from
the site.
Although the NOX pollution potential
meets the current NAAQS, new standards
to prevent significant deterioration are being
evaluated by the EPA for promulgation.
Since these standards have not been estab-
lished and minimal information is available
concerning them, it is difficult to predict
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what concentration increments will be ac-
ceptable. To describe the possibilities ade-
quately, three control scenarios have been
proposed.
The first scenario evaluates the need for
NOX control based on the current NAAQS.
The results of the modeling, discussed
above, indicate that no control is currently
needed. This conclusion assumes that the
full-scale oil shale retort operations include
ammonia recovery as one of the off-gas
treating processes.
Ammonia concentration in the off gas can
be reduced by approximately 85 percent
using a water scrubbing system, or up to 99
percent if an acidic scrubber using sulfuric
acid is used. This ammonia reduction
eliminates the fuel nitrogen in the off-gas and
reduces the potential NOX ambient concen-
tration below the current NAAQS.
The second scenario proposes that a PSD
increment which is 25% of the NOX
NAAQS be evaluated. This proposed incre-
ment is proportional to the increments which
have already been promulgated for sulfur
dioxide and particulate matter (25% of the
respective NAAQS). Using this proposed in-
crement, the permissible concentration con-
tribution desired is 25 /^g N0x/m3. This
would require an approximate 50% reduc-
tion in the current emission rates based on
the air dispersion modeling. Combustion
modification techniques, although not feasi-
ble for pilot-scale construction and testing,
can achieve this reduction.
The third scenario is based on control of
90% of the NOX emissions from the major
sources. Flue gas treatment can achieve this
removal. Eleven NOX control technologies
were considered, including six that could
control NOX and sulfur dioxide
simultaneously. These technologies were
evaluated for applicability, development
status, removal efficiency, relative
economics, and water usage. Table 1 sum-
marizes the five best technologies according
to this evaluation. The best type of flue gas
treatment chosen by applying these criteria
is selective catalytic reduction using a parallel
flow reactor. This control technology, cur-
rently used in Japan, is capable of remov-
ing over 90% of the NOX from oil-fired
boilers, is not affected by large particulate
loadings, and is more economical than
scrubbing processes.
David W. Dunn, Timothy A. Bonner, and Sam C. Cheng are with Monsanto
Research Corporation, Dayton, OH 45407.
Robert C. Thurnau is the EPA Project Officer (see below).
The complete report, entitled "Oxides of Nitrogen/Ammonia Control Technology
for Oil Shale Retort Emissions," (Order No. PB 84-171 453; Cost: $11.50,
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:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
ifr U.S. GOVERNMENT PRINTING OFFICE; 1984 — 759-015/7739
Table 1. Five Preferred NOX Flue Gas Treatment Technologies
Technology
Selective catalytic reduction
by parallel flow reactor
Selective catalytic reduction
by moving bed reactor
Selective catalytic reduction
by parallel flow reactor
for simultaneous SOJ NO,
removal
Selective catalytic reduction
by fixed-bed reactor
Selective noncatarytic reduction
Applicability
Applicable
Applicable
Applicable
Applicable with par-
ticulate removal
Applicable
Status of
development
Full scale,
in use
Full scale,
in use
Full scale,
tests
only
Full scale,
in use
Full scale,
in use
Removal
efficiency
>90%
>90%
>90% NO,
>90% SO,
>90%
40-60%
Economics
Fixed cost: $10,800/ GJ/hr
Operating cost: 420 mills/ GJ
Fixed cost: $19,400/GJ/hr
Operating cost: 500 mills/ GJ
Fixed cost: $130,0001 GJ/hr
Operating cost: 1,400 mills/GJ
Fixed cost: $19,400/ GJ/hr
Operating cost: 530 mills/GJ
Fixed cost: $8.9001 GJIhr
Operating cost: Unknown
Water
usage
Minimal
Minimal
Minimal
Minimal
Minimal
Rating
Good
Good
Fair
Fair
Fair
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Environmental Protection Information
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