United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/S7-88/003 May 1988
&EPA Project Summary
Air Pollution Control
Alternatives for Shale Oil
Production Operations
H. J. Taback and R. J. Goldstick
Air pollution control (APC)
technology is compiled for use by
project developers as well as their
respective regulatory approval
agencies. The processes covered
include mining, raw shale sizing and
handling, various retorting schemes,
spent shale combustion and
disposal, and product upgrading.
Available data on the traditional
processes for nitrogen oxide (NOX),
sulfur compounds, particulate,
volatile organic compounds (VOCs),
and carbon monoxide (CO) control
are discussed. In addition, the report
discusses recently developed APC
technology and processes not
discussed elsewhere in the oil shale
literature; e.g., catalytic mufflers on
vehicles for NOX, VOC, and CO
control; staged combustion for NOX
control; spent shale absorption of
sulfur oxides (SOX); improved filter
bag materials, moving bed granular
filters, and dry Venturis for fine
particulate control; and dry sorbent
injection for SOX control. Data from
seven shale oil project PSD
applications are analyzed and
compared. Finally, five representative
shale oil recovery processes are
analyzed at three levels of emission
control. It is concluded that, if the
most effective levels of control
technology are applied to all five
representative processes, the overall
emission levels (in terms of weight of
emission per unit of oil produced)
will be essentially the same.
Based on the highest level of
control, the emissions (in kilograms
per 1000 m3 of oil produced) that
might be expected from a shale oil
production plant under the best
conditions are about: CO, 200; VOC,
100; NOX, 700; SOX, 200; and TSP, 200.
TA?/s Project Summary was
developed by EPA's Air and Energy
Engineering Research Laboratory,
Research Triangle Park, IMC, 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
Under the Clean Air Act (PL 95-95)
oil shale developers must: (a) employ
Best Available Control Technology
(BACT), (b) ensure that National Ambient
Air Quality Standards (NAAQS) are not
violated, (c) not violate the prevention of
significant deterioriation (PSD) ambient
air quality increments, (d) not significantly
degrade visibility in mandatory Class I
areas, and (e) obtain up to 1 year of
baseline data before applying for a PSD
permit to construct and operate a facility.
Since the environmental impact can be
the limiting factor in developing a
commercial oil shale industry, the EPA
has conducted an on-going research
program to assess existing pollution
control technology, develop new
technology, and quantify the air emission
waste water discharge and solid wastes
-------
associated with the various types of
shale oil recovery facilities.
The EPA's engineering study series,
titled Pollution Control Technical Manuals
(PCTMs), in particular provide a
comprehensive analysis of the air, water,
and solid emissions from specific shale
oil recovery plants.
This report consolidates available air
emissions data and air pollution control
(APC) technology relevant to oil shale
processing operations. It answers six
questions:
What shale oil production processes
are available and how do they
function?
What are the sources of air
pollutants from those processes?
What APC technology options are
applicable to each source; how do
they function; what removal
efficiency can be expected; what do
they cost; and what rationale should
be used to select the most effective
one?
What mass emissions per unit of
throughput (e.g., kilograms/1000m3
of oil) will be released by the various
processes?
What answers to the above
questions have been proposed in
actual PSD permit applications?
Methodology and Findings
Key industry and government agency
personnel were interviewed to gain their
latest experiencbs, impressions of
process performance, and intentions with
regard to future ^developments. The
emissions factors;for mining, retorting,
and upgrading processes were then
evaluated. A matrix was prepared
summarizing APC options for each unit
process of certain selected shale oil
production facilities. Each standard APC
technique identified in the matrix is
synopsized, and the newer and more
innovative APC techniques are discussed
more extensively. Table 1 summarizes
the technologies presented.
Next, the PSD:permit applications of
seven shale oil projects were evaluated.
This information was computerized and
sorted to determine average emissions
and relative percentages for each
process. Signifidant differences in the
estimating procedures for the various
projects are discussed. The PSD permit
applications analysed are listed in Table
2. ;
Finally, as an example of specific
case studies, the APC alternative for five
shale oil production processes were
determined.along with their associated
mass emission rates: (1) direct heated
(e.g.,Paraho); (2) travelling grate
(e.g..Superior, Allis-Chalmers, Dravo);
(3) indirect heated (e.g.,Union B); (4)
recycled solids (e.g..Chevron, Lurgi); and
(5) modified in-situ (e.g..Occidental).
For this analysis, constant emission
rates were established for mining and
product upgrading operations. These
were based primarily on the seven PSD
applications.supplemented with literature
values as needed. The area where
technology selection had a profound
effect on the estimated emissions was in
the method of retorting the shale and the
associated process used to scrub the
offgas streams. Figures 1, 2, and 3,
respectively, give the particulate, NOX,
and SOX emissions from the retorts of the
five design cases.
These three figures indicate that there
is wide variation in the base case
emission levels for the five processes
which are based on the present state-
of-the-art technology as reflected in
the seven PSD permit applications. For
particulates, the emission levels vary
from 200 to 800 kg/1000 m3 of oil; for
NOX the emission levels vary from 1000
to 8000 kg/1000 m3; and for SOX the
Table 1. Air Pollution Control\Technologies
Pollutant Control Technology
Particulate
(Point Sources)
(Fugitive Sources)
Nitrogen Oxides
Sulfur Compounds
Carbon Monoxide
and Hydrocarbons
Baghouse
Venturi scrubber
Electrostatic precipitator
* Dry Venturi
Surfactants
Liners
Wind screens
Chemicals
Water spray
Staged combustion
Ammonia injection
Selective catalytic reduction
Stretford
Lot-Cat
Unisulf
Alkaline scrubber
* Activated carbon and hypochlorite
Claus
Scot (Shell-Claus offgas treating)
Flue gas desulfurization (wet & dry)
* SOX Absorption on spent shale
* Catalytic mufflers
'Indicates systems given greater emphasis in this report
because they are not covered in other shale oil documents.
-
-------
Table 2. PSD Permit Applications Evaluated
Oil
Production
Project
Cathedral Bluffs
Clear Creek
Utah Cottonwood
Wash
Paraho - Ute
Syntana
Union Facility
White River Project ,
Location
Rio Blanco County, CO
Grand Valley, CO
Green River Basin, UT
Uinta Basin, UT
Uinta County, UT
Parachute Creek, CO
Vernal, UT
m3/day
1,900
15,900
5,000
6,700
9,100
14,300
16,900
Retort Process
Modified in-situ with Union
above-ground retort
Chevron - fluidized bed with
solids recycle
T3 retort with fluidized bed
combustion of retort gas & fines
Paraho/direct heated
Superior - retort indirect heat with
Tosco II retort for fines
Indirect combustion, gas recycle
Superior-direct heated
Union B-indirect heated
Tosco ll-fines retort
emission levels vary from 350 to 3000
kg/1000 m3.
ARC Alternative No. 1 was the use of
the activated carbon hypochlorite
enhanced H2S removal process, an acid
wash for improved ammonia removal.and
the addition of a dry venturi-baghouse
for post-combustion particulate control.
Referring to Figures 1, 2, and 3, the
emission levels for Alternative No. 1
show considerably less variation,
particularly for SOX (from 100 to 250
kg/1000 m3 of oil) and particulates (from
50 to 200 kg/1000 m3 of oil). The
variation of NOX emission is still
considerable (from 1000 to 4000 kg/1000
m3 of oil). Essentially, the acid wash
removes only the residual ammonia
without affecting the organic nitrogen
cbntent and has no effect on thermal
NOX; therefore, there is relatively little
improvement in the NOX emission rate.
ARC Alternative No. 2 was the
addition of ammonia injection for NOX
control from boiler and/or furnace
combustion, the use of staged
combustion for control of NOX emissions
from the spent shale* combustor, and the
dry venturi-baghouse with increased
space velocity which improves collection
performance at the expense of increased
pressure drop. Again, referring to Figures
1, 2, and 3, it is apparent that the
addition of these controls essentially
levels the performance of all five
processes.
Conclusion
The basic conclusion derived from the
above analysis is that, although the air
emission levels for the different retort
processes with controls proposed in PSD
permit applications between 1980 and
1985 can vary considerably (sometimes
by as much as two orders of
magnitude),the application of control
techniques that are either improvements
over existing technology or more suitable
for a specific application, can reduce
emissions and result in similar emission
levels for all five processes. This
conclusion needs to be qualified: some
of the control techniques considered
have not yet been applied specifically to
the oil shale recovery process. However,
these techniques have been proven at
the full scale level in various other
difficult control applications.
Reference
Taback, H. J., et al., "The Effect of Oil
Shale Recovery Processes on Air
Emissions," 19th Oil Shale
Symposium Proceedings, Colorado
School of Mines Press, Golden, CO,
1986.
-------
900
800
700
600
500
400
^ 300
"* 200
100
0
Figure 1.
go
I "5
.§"6
11
•• #r #2
tts
Base Case
#4 #5
Alternate #1
Alternate #2
Paniculate emissions from retorf gas combustion for five cases. (Taback, H. J.,
et at., 1986). ;
Base Case Alternate #1 Alternate #2
Figure 2. Nitrogen oxides emissions summary for five cases. (Taback, H. J., et a/., 1986).
3000• •
Base Case Alternate #1 Alternate #2
Figure 3. Sulfur oxides emissions summary for five cases. (Taback, H. J., et a I.,
1986).
-------
-------
H. Taback and R Goldstick were formerly with KVB, Inc., Irvine, CA 92714.
Edward R Bates is the EPA Project Officer (see below). '
The complete report, entitled "Air Pollution Control Alternatives for Shale Oil
Production," (Order No. PB 88-196 027/AS; Cost: $44.95, subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road i
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 i
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S7-88/003
Government Printing office: 1983-548-151/67128
------- |