United States
Environmental Protection
Agency
Office of
Reseach and
Development
L.ibor.ilory
RrsiMti li
P,itk. NoMh C
FPA-tiOO
THE U.S. ENVIRONMENTAL
PROTECTION AGENCY'S
FLUIDIZED-BED
COMBUSTION PROGRAM,
FY 1976
Interagency
Energy-Environment
Research and Development
Program Report
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S.
Environmental Protection Agency, have been grouped into seven series.
These seven broad categories were established to facilitate further
development and application of environmental technology. Elimination
of traditional grouping was consciously planned to foster technology
transfer and a maximum interface in related fields. The seven series
are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from
the effort funded under the 17-agency Federal Energy/Environment
Research and Development Program. These studies relate to EPA's
mission to protect the public health and welfare from adverse effects
of pollutants associated with energy systems. The goal of the Program
is to assure the rapid development of domestic energy supplies in an
environmentally—compatible manner by providing the necessary
environmental data and control technology. Investigations include
analyses of the transport of energy-related pollutants and their health
and ecological effects; assessments of, and development of, control
technologies for energy systems; and integrated assessments of a wide
range of energy-related environmental issues.
REVIEW NOTICE
This report has been reviewed by the participating Federal
Agencies, and approved for publication. Approval does not
signify that the contents necessarily reflect the views and
policies of the Government, nor does mention of trade names
or commercial products constitute endorsement or recommen-
dation for use.
This document is available to the public through the National Technical
Information Service, Springfield, Virginia 22161.
-------
EPA-600/7-77-012
February 1977
THE U.S. ENVIRONMENTAL PROTECTION
AGENCY'S FLUIDIZED-BED
COMBUSTION PROGRAM, FY 1976
Batte lie-Columbus Laboratories
505 King Avenue
Columbus, Ohio 43201
Contract No. 68-02-2138
Program Element No. EHE623A
EPA Project Officer: D. Bruce Henschel
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office o? Research and Development
Washington, DC 20460
-------
CONTENTS
SUMMARY v
INTRODUCTION 1
THE SCOPE OF THE EPA FLUIDIZED-BED COMBUSTION PROGRAM 2
A. Environmental Assessment 4
B. Comprehensive Analysis of Emissions 5
C. Pretreatment of Input Streams 14
D. Modification of Process Conditions 14
S07 Emission and Sorbent Requirement 15
NO Emissions 15
X
Particulate Emissions 20
Alternative Sorbents 22
Trace Element Emissions 22
Other Pollutants 23
E. Add-On Controls 25
Mobile Control Devices 25
Sampling and Analytical Test Rig 27
Particulate Control Test Facility 27
Miniplant Ducon Filter 28
Regeneration of Sorbent 28
Other Work 30
F. Solid Waste Disposal 31
Scope of Current EPA Solid Waste Program 31
Characterization of Spent-Bed Materials 32
ill
-------
CONTENTS
(Continued)
Environmental Impact of Disposal 34
Utilization and Marketing 37
Future Studies 37
G. Application Studies 39
Application of FBC to Industrial Boilers 39
Cost Comparison Studies 40
Studies on Effect of Scale-Up 40
RELATIONSHIP OF THE EPA PROGRAM TO THE DEVELOPMENT PROGRAMS.. 40
ERDA Development Program 41
EPRI Development Program 41
International Development Programs 43
EPA Contributions to the Development Programs 44
BIBLIOGRAPHY '. 48
APPENDIX A 52
iv
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SUMMARY
A vital element of the National Program on Fluidized-Bed
Combustion (FBC) of coal for space-heating, steam-generation, and power-
generation applications is the U.S. Environmental Protection Agency (EPA)
program on the environmental characterization and control of this process.
The goal of the EPA FBC program is to obtain all necessary environmental
data over the full range of operating variables for all variations of the
FBC process. It is EPA1 s responsibility to assure that all environ-
mental problems are identified and adequately addressed. Conducting the
environmental characterization in parallel with the process development
program increases the likelihood of early detection and control, at a
minimum cost, of any potential environmental problems that might result
during commercial application of FBC.
Some of the important contributions that the EPA program will
make to the National FBC program are:
• Establishment of environmental goals based on
health and ecological effects of emitted
pollutants,
• Comprehensive analyses of emissions from avail-
able operating units in order to identify
emitted pollutants and their emission rates,
• Assessment of the feasibility and costs of
existing and future control technology,
• Generating valuable technical information on
control technology including: (1) pretreatment
of input streams, (2) modification of process
conditions for environmental control, (3) add-
on control devices (including sorbent regeneration),
(4) environmental impact of solid residue disposal,
and (5) applications (paper) studies,
• Recommendations for environmental standards based
on environmental goals, control technology capa-
bility, and costs,
• Development of manuals covering the best available
technology for controlling emissions based on
the assessment of available control technology.
-------
The EPA's Environmental Assessment and Control Technology
Development (EA/CTD) program is coordinated with the technology develop-
ment program for FBC being conducted by the U.S. Energy Research and
Development Administration (ERDA). A large portion of the EPA testing
(e.g., comprehensive analysis, and control technology) will be performed on
ERDA units. Similarily, ERDA will use the EPA's pressurized FBC Miniplant
for process development studies. EPA and ERDA are co-funding experimental
work at Argonne National Laboratory and an industrial boiler applications
study at Exxon Research and Engineering Company.
The EPA program consists of tasks on environmental assessment,
comprehensive analysis of emissions, and control technology development.
All of these tasks contribute to an overall technology assessment of the
FBC process. The objectives of environmental assessment are: (1) to set
emission goals based on health and ecological effects of emitted pollu-
tants and (2) to identify and recommend research, development, and demon-
stration programs designed to develop the necessary information and control
technology to implement these goals. Comprehensive analysis of emissions
from operating units provide data on pollutants and their emission rates
in order to identify the degree of control that may be required to meet
emission goals. Control technology development efforts include engineering
analysis, basic and applied research and development, and specific control
process development. The contractors currently involved in this program
are Battelle's Columbus Laboratories (BCL); GCA Corporation; the British
Coal Utilization Research Association (BCURA) with Combustion Systems,
Ltd. (CSL); Exxon Research and Engineering Company; the MITRE Corporation;
Ralph Stone and Company; Tennessee Valley Authority (TVA); Westinghouse
Research Laboratories; Argonne National Laboratory (ANL); Aerotherm-Acurex
Corporation (AAC) and Dow Chemical Company (DCC).
The major accomplishments during the past fiscal year related to
environmental assessment include a preliminary environmental assessment
program completed by GCA and the initiation of a major contract with BCL
for a broad environmental assessment. The preliminary assessment by GCA
indicated that, except for major air pollutants which have been routinely
monitored during operation of experimental FBC facilities, there were in-
sufficient experimental data upon which to base firm conclusions concerning
potential environmental problems for FBC. BCL has made several preliminary
planning studies to define needed research areas for improving the data
base. BCL has also initiated the development of a multimedia environmental
goals (MEG) chart which is a concept for developing emission goals for
specific pollutants based upon health/ecological effects data. Comprehensive
analysis was initiated on a 6-inch (15.24 cm) diameter atmospheric-pressure
FBC unit at BCL and was about to begin on a 2-foot by 3-foot (0.6 by 0.9 m)
pressurized unit at BCURA; planning is underway for comprehensive analysis
on other units in 1977, including the Exxon 0.63-MW pressurized Miniplant
and the Rivesville 30-MW atmospheric boiler. A potential problem involving
SO., production from FBC units at Exxon and BCL was also identified. A few
measurements of 94 ppm or higher were obtained, although the average was
VI
-------
only 5-6 ppm. These readings may be related to sampling techniques and must
be further investigated to determine if a significant SO- problem exists
in FBC combustors.
In the area of control technology development, the major accom-
plishments involved investigations on (1) pretreatment of input streams
at Westinghouse, ANL, and Exxon; (2) effects of modification of process
conditions at Exxon, ANL, and Westinghouse; (3) development of add-on
devices at Exxon, ANL, and Westinghouse, (4) characterization, disposal,
and utilization of solid residue at TVA, Westinghouse, and Ralph Stone; and
(5) FBC applications at Exxon, TVA, and Dow. The aim of the pretreatment
studies is to improve the efficiency of limestone and dolomite sorbents.
Experimental studies conducted by Exxon, ANL, and Westinghouse have shown
that precalcination improves sorption efficiency and the effect is more
pronounced for pressurized systems. Pope, Evans and Robbins earlier found
that common salt improves sorption efficiency and ANL is investigating
the mechanism in order to promote practical application including use of
less corrosive additives. Studies on the effects of modifcation of pro-
cess conditions included a 240-hour demonstration run of the combustor of
the Exxon Miniplant. Tests with the Miniplant and the ANL bench-scale
combustor/regenerator system were used to identify the calcium to sulfur
ratio necessary for meeting emission standards in pressurized FBC units.
Tests on the effects of additives on limestone performance were also made.
The effects of alternate sorbents were investigated by ANL and Westinghouse
and Westinghouse also examined the effects of attrition on the regeneration
capacity of calcium and alternate sorbents. Studies on the development
of add-on controls include the initiation of shakedown runs on the re-
generator and installation of a granular bed filter on the Exxon Miniplant.
ANL has examined the factors involved in the one-step regeneration of
sorbents and Westinghouse has designed a test facility to study particulate
control at high temperature and elevated pressure. EPA has developed a
mobile system to test atmospheric particulate control devices and this
system will be tested on FBC units as soon as practical. The solid residue
studies on utilization have been conducted by Ralph Stone who along with
Westinghouse, has also been conducting studies on disposal, leaching, and
low-temperature processing of the residue. Westinghouse, Ralph Stone, and
TVA have been conducting studies on characterization of the solid. The
Exxon applications study concluded that FBC is applicable to industrial
boilers and can be more economical than conventional coal-fired boilers with
flue gas scrubbing. The TVA study is comparing costs of FBC utility boilers
with conventional units. The Dow study attempted to examine the effects
of scale-up on pollutant emissions but could not reach any definite con-
clusions .
Major outputs anticipated during the next year under the cate-
gory of environmental assessment are (1) progress in setting environmental
goals based on health and ecological effects (including the first complete
pass at producing the MEG chart); (2) comprehensive analysis on additional
facilities including the 18-inch (45.7-cm) diameter unit at Morgantown
Energy Research Center, the Miniplant combustor, the Rivesville unit, and
vii
-------
the BCURA unit; and (3) initiation of the work to prepare preliminary
recommendations of standards for atmospheric FBC units. Under the category
of control technology development, some anticipated outputs are (1) further
testing on the Miniplant including studies on pretreatment (precalcination
of sorbent), modification of process conditions (different coal and sor-
bent combinations), and add-on devices (shakedown and operation of the
Ducon granular bed filter plus completion of the shakedown and operation of
the regenerator); (2) installation and initial testing on the Westinghouse
high-temperature, high-pressure particulate control test passage; (3) test-
ing of the EPA mobile particulate control devices on the Rivesville unit
if the ERDA schedule permits; (4) further process studies and regeneration
testing at ANL and Westinghouse; (5) further solid residue tests including
establishment of field test cells using residue from various FBC units;
(6) completion of the TVA study on cost comparisons of FBC versus flue gas
desulfurization; (7) completion of the Exxon study on the assessment of
industrial FBC applications; and (8) completion of the FBC sampling and
analysis manual by MITRE.
viii
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THE U.S. ENVIRONMENTAL PROTECTION AGENCY
FLUIDIZED-BED COMBUSTION PROGRAM
Annual Program Status Report for the Period
July 1, 1975 to September 30, 1976
INTRODUCTION
Fluidized-Bed Combustion (FBC) of coal offers the potential for
efficiently utilizing the country's large reserves of high-sulfur coal in
a manner that controls the emissions of environmentally harmful pollu-
tants associated with conventional combustion of coal.
The U.S. Environmental Protection Agency (EPA) recognized this
potential and was a key sponsor of some of the early development work on
this process. Current EPA activities are designed to complement those of
the U.S. Energy Research and Development Administration (ERDA) which is
presently conducting a substantial program to develop this technology
toward space-heating, steam-generation, and power-generation applications
and of the Electric Power Research Institute (EPRI) which is also con-
ducting development programs aimed more specifically toward the needs of
the power-generating industry. The EPA is closely monitoring additional
development work outside the United States, especially in the United
Kingdom.
The EPA program is aimed at the complete environmental charac-
terization of FBC. It is EPA's responsibility to ensure that environ-
mental concerns are identified and adequately addressed. Conducting the
environmental characterization in parallel with the development programs
increases the likelihood of early detection and control, at a minimum
cost, of any potential environmental problems. The EPA program will make
a number of important contributions to the overall U.S. program:
• Establishment of environmental goals based on
health and ecological effects of emitted pollu-
tants ,
• Comprehensive analyses of emissions from avail-
able operating units in order to identify emitted
pollutants and their emission rates,
• Assessment of existing and future control
technology,
• Provide valuable technical information on control
technology including: (1) pretreatment of input
streams, (2) modification of process conditions
for environmental control, (3) add-on control
devices (including sorbent regeneration), (4) en-
vironmental impact of solid residue disposal,
and (5) applications (paper) studies,
-------
• Recommendations for environmental standards based
on environmental goals, control technology capa-
bility, and costs,
• Develop manuals covering the best available tech-
nology for controlling emissions based on the
assessment of available control technology.
The goal of the EPA FBC program is to obtain all necessary
environmental data over the full range of operating variables for all
variations of the FBC process. Plans are to obtain these data on a
suitable experimental scale and on a time schedule compatible with the
process development schedule envisioned in the national FBC development
effort. It is anticipated that these data will be adequate to assess the
total environmental impact of the process on all media (air, water, land)
so that there will be assurance that the process will meet current and
anticipated environmental standards. It will be necessary to have
sufficient data available to serve as a basis for recommending additional
standards, if future health effects studies or related work identify
the need for such standards. Also, adequate data on suitable control
technologies must be developed as a means to minimize the environmental
impact.
THE SCOPE OF THE EPA FLUIDIZED-BED COMBUSTION PROGRAM
The EPA FBC program currently consists of 19 projects with a
variety of contractors. It is supported by a general program for
developing sampling and analytical techniques. For contractual purposes
these projects have been arranged into five categories as shown in Table
A-l and Figure A-l of the Appendix. Table A-l and Figure A-l also pro-
vide a brief schedule and status report on these projects. Figure 1
shows the functional structure and interrelationship of these projects.
The relationship of the EPA program to the other FBC development programs
is covered in a separate section.
The aim of environmental assessment is to set emission goals
based on health and ecological effects of the emitted pollutants and to
design research, development, and demonstration programs to compile the
necessary information and control technology to implement these goals.
Comprehensive analyses of emissions from operating units provide data on
pollutants and their emission rates in order to identify the degree of
control that may be required in order to meet the goals. The control
technology development effort includes tasks on pretreatment, modification
of. process conditions, add-on devices, and solid residue disposal. The
application studies examine control technology based on fluidized-bed
combustion in terms of applicability to industrial boilers, costs in
comparison to conventional boilers, and scale-up considerations. All of
these projects contribute to an overall assessment of the FBC technology.
-------
EPRI AND
INTERNATIONAL
PROGRAMS
EPA PROGRAM
1
ERDA PROGRAM
ENVIRONMENTAL ASSESSMENT
BROAD ENVIRONMENTAL ASSESSMENT-
DEFINE ENVIRONMENTAL GOALS
Battelle (AD*, GCA (A2)
COMPREHENSIVE ANALYSIS OF
EMISSIONS
Battelle (A1. B1, B5), TRW (B1),
BCURA (B2), Exxon (83). SATR (84)
DEFINE R&D NEEDS
(COMPARE GOALS AND EMISSIONS)
Battelle (AD
COMPREHENSIVE
ANALYSIS
SUPPORT
Mitre (B6),
Variou*
Contractors (B7)
•Numtwn In fMrmth«tM Mf«r to
prajKt idmtificatfon in TiM« A-1
and Flgui* A-1 en pagn A-1 through
A-3.
CONTROL TECHNOLOGY DEVELOPMENT
PRETREATMENT
Weitinghouse (CD, Argonrw (C2),
Exxon (C3)
MODIFICATION OF PROCESS
CONDITIONS
WeitinghouM (CD, Argonna (C2),
Exxon
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A. Environmental Assessment
The main objectives of the FBC environmental assessment (EA)
effort are to (1) identify and quantify all pollutants which could be
emitted by the process as it gains commercial acceptance, (2) recommend
emission goals based on health and ecological effects of pollutants, in-
cluding an approach utilizing a Multimedia Environmental Goals (MEG)
chart, (3) conduct comprehensive analysis of emissions from FBC units
(discussed in the following section), and (4) define a research and
development program to obtain any necessary information and to develop
necessary control technology.
In a preliminary study by the GCA Corporation, it was concluded
that, except for major air pollutants, which have been routinely monitored
during operation of experimental FBC facilities, there are insufficient
data to base firm conclusions concerning potential environmental problems
for FBC. Approximate theoretical assessments did not indicate any special
environmental problems but experimental verification of this conclusion
is necessary and should receive high priority.
The primary EA program was initiated with Battelle's Columbus
Laboratories in January, 1976, and some of the specific products will be
(1) manuals of best available control technology (MBACT) and (2) recommen-
dations for emission standards for FBC. Thus far, Battelle has (1) com-
pleted the assessment of the current process/environmental background and
has concluded that there exists a serious lack of experimental data on
emission trace elements and compounds, and organic compounds; (2) begun
to assist EPA to develop an overall plan of concerted experimental efforts
at collection of needed environmental data; (3) defined an approach to
a MEG chart as a tool for goal setting; (4) drawn up plans for comprehen-
sive analysis of emissions at various ERDA- and EPA-operated FBC
experimental facilities; and (5) initiated several technical program
planning studies to define research areas and directions which should be
addressed immediately to accelerate the FBC development and EA effort.
These include alternative sorbents, regeneration, NO formation and con-
trol, trace elements, solid/liquid wastes, and particulate control.
Battelle has also obtained first-hand information on the status
of worldwide FBC research and has concluded that efforts in the United
States toward the development and environmental impact assessment of FBC
are comprehensive in the depth and breadth of planned studies. Further,
the ongoing EA work in the United States stands out as unique and un-
paralleled, in that no other country has embarked, even on a reduced scale,
on developing environmental impact data concurrent with the development
of the process.
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A draft MBACT for the atmospheric FBC process is scheduled
for issue in December, 1978. Preliminary recommendations to set standards
for atmospheric FBC are scheduled to be prepared by December, 1977, with
updated recommendations in December, 1978. A draft MBACT, and recommen-'
dations for standards for pressurized FBC will be prepared later. The
manuals and recommendations will initially be based on data from the
largest facilities existing at the time (Rivesville, the Exxon miniplant,
the BCURA unit), and it will be updated as further data become available
from additional units.
The Multimedia Environmental Goals (MEG) chart is a concept
developed by the Industrial Environmental Research Laboratory (IERL) of
EPA which, when carried through to a successful completion, will provide
the emerging energy technologies with a unified presentation of environ-
mental goals in all media. A sample MEG chart is shown in Figure 2. The
format of the chart presents emission goals for specific pollutants from
a specific process in all media (air, water, and land) in terms of best
technology (Columns IA and IB), and in terms of desired ambient levels
from the health/ecological effect standpoint (Column 1C). Those emission
goals based on health/ecological effects are derived from desired ambient
levels determined by: current/proposed standards (Column II); toxicity-
based permissible concentrations, such as concentrations based on threshold
limit values (Column III); and mutagenic/carcinogenic/teratogenic-
permissible concentrations (Column IV).
By comparing emissions from FBC units measured during the com-
prehensive analysis program, or the emissions expected using developing
control technology (Columns IA and IB) with the health/ecological effects
goals in Column 1C, EPA can make decisions regarding how the control
technology development program should be directed. A preliminary version
of the MEG chart is under development. An updated MEG chart for FBC is
scheduled for completion by December, 1978.
B. Comprehensive Analysis of Emissions
An indispensible component of the FBC environmental assessment
process is the actual measurement of emissions. The measurement must be
comprehensive, in that all streams of materials leaving the process must
be identified whether they be continuous or intermittent, steady or vari-
able, and whether they are gaseous, liquid, solid, or any combinations
thereof. Streams of any size must be considered, and sound technical
judgment, based on a thorough familiarity with the processes involved,
must be applied to ensure that every possible effluent stream that might
contribute an undesirable substance to the environment is considered.
The comprehensive characteristic of the analysis also demands that these
streams be analyzed for all possible pollutants. Comprehensive analyses
of this magnitude applied to a complex process like fluidized-bed com-
bustion systems is very extensive and time consuming, and thereby expen-
sive. To meet the complex demands of the comprehensive analysis of
emissions in the most cost-effective manner, a phased approach of sampling
and analysis of emissions has been developed. This involves three levels
of activity:
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MULTIMEDIA ENVIRONMENTAL GOALS FOR
(Pollutant:)
MEDIA
AIR, Mg/ra
(ppm vol)
WATER, mg/1
(ppm wt)
Public
Drinking
Water
Freshwater
Ecological
Marine
Ecological
LAND, pg/g
(ppm wt)
Emission-Level Goals
I
Best Technology
A
Existing Tech,
NSPS. BPT**
B
Developing
Tech, BATf*
Revised NSPS
Based on Ambient Factors
C
Derived from
Ambient-Level
Goals
(Cols 11,111, IV)
D
Elimination of
Discharge (EOD)
Natural
Background
Ambient-Level Goals
II
Current or Proposed
Ambient Standards
or Criteria
A
Based on
Health
Effects
B
Baaed on
Ecological
Effects
III
Toxicity-Based Eat.
of Permissible
Concentration (EPC)
A
Based on
Health
Effects
B
Based on
Ecological
Effects
IV
Threshold Limit-
Based EPC (for
Carcinogen, etc)*
A
Based on
Health
Effects
* Acceptable death rate should be defined and natural background levels should be considered; whereas TLV data usually consider physiological
or behavioral effects, threshold limit in this case refers to genetic (carcinogenic, teratogenic, mutagenlc, etc.) effects.
** BPT - Best Practical Control Technology; NSPS = New Source Performance Standards; BAT = Best Available Control Technology.
FIGURE 2. SAMPLE MULTIMEDIA ENVIRONMENTAL GOALS (MEG) CHART
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Level 1: The identification and measurement of
all possible pollutants or classes of pollu-
tants in all effluent streams, with the
degree of accuracy considered to be of secondary
importance.
Level 2: The more accurate measurement of
specific pollutants in specific streams where-
ever Level 1 measurements indicated that un-
acceptable emissions might be occurring,
considering the accuracy limitations obtained
in Level 1 measurements.
Level 3: The measurement of significant pollu-
tants (as identified in Levels 1 and 2) over
extended periods of time. This program of
measurements must be planned to demonstrate
correlations of these pollutant emissions with
time, operating conditions, feed stream compo-
sition, emission control techniques, and other
operational parameters that might affect
emissions.
In the case of comprehensive analysis of emissions from fluidized-
bed combustion units, there is some existing knowledge concerning likely
emissions of some pollutants (such as SC^, NOX, particulates, etc.)- This
prior knowledge justifies the inclusion of some Level 2 measurements in a
comprehensive analysis experimental program which would otherwise include
sampling and analyses only at the Level 1 depth and accuracy. Using this
background knowledge of FBC emissions, a sampling and analysis plan has
been developed by Battelle for application to laboratory and developmental
combustors. The plan is readily expandable to larger demonstration units
and to specialized units such as pressurized FBC units and those including
sorbent regeneration.
Table 1 shows a simplified matrix of representative effluent
streams and the pollutant species identified for analysis in each stream.
Examples of the Level 2 analyses are the identification and measurement of
specific POM compounds by gas chromatography-mass spectrometry in the
effluent stack gas stream (gaseous and particulate) and the more accurate
measurement by AA of a few trace elements known to be especially toxic.
These two specific pollutant classes are of concern because the combustion
conditions attained in the FBC process (1) preclude fixing of trace ash
constituents in a fixed glassy matrix customarily obtained in conventional
coal burning and (2) possibly permit release of coal fragments (polycyclics)
into the effluent flue gas. As this program of sampling and analysis is
applied to specific units, details of the matrix of measurements must be
expanded to include the specific effluent streams appropriate to that FBC
unit.
As part of the comprehensive analysis effort, the MITRE Corpora-
tion is preparing a Level I/Level 2 sampling and analysis procedures manual
for each of the fluidized-bed combustion process variations. The manual
indicates alternative sampling and analytical procedures that can be
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TABLE 1. SAMPLING AND ANALYSIS MATRIX FOR COMPREHENSIVE ANALYSIS OF FBC STREAMS
Species, Pollutants
Qn-Line Continuous Gas Measurements
CO2
SO2
NO
NO2
CO
02
Total Gaseous Hydrocarbon
ntegrated Gas Phase Measurements
HjS
COS
Oisulfides
S03/H2S04
NH3
Cyanides
HCI
Fluoride, volatile
ntegrated Specimens for Subsequent
Group Analysis
Trace metals
Major Elements (Fe, Al. Si. K, Ca)
Organic, by class
Organic-reduced, sulfur compounds
POM
Proximate
Radionuclides
Ultimate
Sulfur forms
Biological
Integrated Specimens for Subsequent
Specific Analysis
Toxic Elements (Be, Cd, Hg, As,
Pb, Se, Sb, Tel
cr
F~
Na
Ca
Mg
C03"
S04=
S03=
s-
NO2"
NO3-
C "Non Carbonate"
Heating value
Particle morphology
Particle size
Particle mass
Sample
Collection
Techniques'1'
Cw
Cw
Cw
Cw
Cw
Cw
Cw
ig
19
ig
St
St
St
St
St
SASS/Gs
SASS/Gs
SASS/Gs
SASS/Gs
SASS/Gs
Gs
SASS/Gs
SASS/Gs
Gs
SASS/Gs
SASS/Gs
SASS/Gs
SASS/Gs
Gs
Gs
Gs
SASS/Gs
SASS/Gs
SASS/Gs
SASS/Gs
SASS/Gs
SASS/Gs
Gs
Gs
Gs/Ci
Gs/Ci
M5
Analysis Method""1
NDIR
IR or UV
NDIR or CL
NDIR or CL
NDIR
PM or PE
FID
GC
GC
GC
GR/IC
KJ
CO
Tl
SIE
SSMS
OES
EX/LC/IR
GC
GC/MS
ASTM D31 72-73
Gross a and P assay
ASTM D3176-74
ASTM D2492-68
In vitro
AA
CO
DI/CO
AA
AA/TI
AA
GE
TI/IC
S02 GE/CO
GE/TI
CO/IC
CO/IC
c
ASTM 02015-66
SEM
Sieve - ASTM 410-38
Weight
System Stream or Material
Stack
Pirttculatei
Mid
>3n
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X'd
Fine
<3»i
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Gat
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Wane
from cyclone
and bed
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Coal
Feed
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Sorbent
Feed
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Leachate
from
Solid Waste
(cyclone and
bad)
X
X
X
X
X
X
X
X
(a) Cw - Continuous withdrawal through non-reactive line
with mechanical filtration.
Ig • Integrated grab sample of gas in glass bulb.
St - Separate wet chemical train to collect gas (such
as Method 6).
SAAS - Source Assessment Sampling System (train used
for suspended particulates, organic*, and
volatile trace elements).
Gs - Grab multiple samples riffled to reduce to 100 g
representative sample.
Ci - Cascade impactor in flowing stream.
MB - EPA Method 5.
(c) Coarse (>10>) and Filter Kl/t) fractions included.
(b) NDIR - Non-dispersive infrared. SSMS
IR - Infrared. OES
UV - Ultraviolet. EX
CL - Chemiluminescence. LC
PM - Paramagnetic. GC/FPD
PE - Platinum Electrode.
FID - Flame lonization Detector. GC/MS
GC - Gas Chromatography.
GR - Goksoyr-Ross. AA
1C - Ion Chromatography. Dl
KJ - Kjeldahl. GE
CO - Colorimetric. C
Tl • Tltration. ASTM
SIE - Selective-Ion Electrode.
SEM
• Spark Source Mass Spectroscopy.
• Optical Emission Spectroscopy.
- Extraction.
- Liquid Chromatography.
- Gas Chromatography with flame
photometric detector.
- Gas Chromatography with mass
spectrography.
- Atomic absorption.
• Distillation.
- Gas Evolution.
- Combustion.
• American Society for Testing
Materials Standard Method.
• Scanning Electron Microscope.
-------
employed for the various potential pollutants for each variation, recom-
mends preferred procedures, and identifies sampling and analytical tech-
nique research and development requirements. The manual is to be
published in 1977.
In addition to these comprehensive analysis efforts, an exten-
sive continuing effort is underway by EPA with a variety of contractors
to develop new and improved sampling and analytical techniques. This
effort is not part of the FBC program per se, but is in support of all
of EPA's activities. As an example of the type of support provided by
this effort, a Source Assessment Sampling System (SASS) has been
developed by Aerotherm/Acurex which will be utilized in the Comprehensive
Analysis Program. Figure 3 shows this system, which measures participate
mass and size distribution, organics, and trace elements. Another part
of this effort is the development of a procedures manual for biological
testing of the environmental effects of effluents from a wide variety of
industrial processes. This is being done by EPA with assistance from
Battelle. The Process Measurements Branch of 1EKL is also preparing a
general guidelines document, procedures manuals, and technical manuals
for sampling and analysis.
Two extensions of the comprehensive analysis of emissions are
considered appropriate for FBC units. One overall objective of the
analyses is to provide data to aid in the development and evaluation of
control devices. Therefore in some situations within-system streams
must be sampled and analyzed to a limited degree to provide this infor-
mation. For example, particulate concentrations and characterization in
the inlet to particulate control devices should be included, even though
the stream at this location does not constitute an emission from the FBC
unit. The second extension is the development and consideration of a
simplified characterization of leachate from solids discarded from the
FBC system. Because the solids from the bed and particulate collection
devices destined to be discarded will probably be subject to some natural
water leaching, some simple screening analysis of this leachate as a
secondary emission should be considered. Follow-on evaluations of
leachate properties will ultimately be required in site-specific experi-
ments for each production and large demonstration FBC unit. A more
detailed study of solid waste and leachates is described later.
During the next year, specific plans are being made to conduct
comprehensive analysis of emissions from five FBC units as follows:
Type
Operator
Location
Size
Pressure
Current
Status
Sampling
Schedule
Fuel
Sorbent
Laboratory
BCL
Columbus,
Ohio
6" diam.
atmos
operational
completed
4/76
coal
limestone
Pilot
BCURA
Leatherhead,
England
2' x 3'
pressurized
operational
scheduled
4Q/76
coal
limestone
Pilot
MERC
Morgantown,
W. Va.
18" diam.
atmos
being
modified
sampled
9/76
culm
none
Pilot
EXXON
Linden,
N.J.
12" diam.
pressurized
being
modified
planned
4Q/76
coal
dolomite
Demons tration
PER
Rives ville,
W. Va.
38' x 12'
atmos
construction
planned
mid-1977
coal
limes tone.
-------
Convection
"oven
Filter
Slock T.C.
Cos cooler
Imp/cooler
trace element
collector
Orifice AP
Dry test meter
FIGURE 3. SOURCE ASSESSMENT SAMPLING SYSTEM (SAAS)
10
-------
Additional comprehensive analyses will be considered when additional FBC
units become operational, especially the larger units being planned in
conjunction with ERDA programs and by industrial concerns.
The comprehensive analysis of emissions on Battelle's experi-
mental FBC unit have been completed. This unit is of laboratory scale
and used normally for process development. The combustion chamber is
circular in cross section with metal walls and has no submerged cooling
coils. A sketch of the unit is shown in Figure 4. During the compre-
hensive analysis of emissions, the operating conditions were within the
following ranges:
Coal feed rate 4.1-7.7kg/hr (9-17 Ib/hr)
Limestone feed rate 2.0-8.2kg/hr(4.3-18 Ib/hr)
Air rate 39.5-68.5kg/hr ( 87-151 Ib/hr)
Bed height 122cm (48 in)
Bed temperature 830-900 C (1525-1655 F)
Superficial gas velocity 183-287cm/sec (6.0-9.4ft/sec)
Ca/S ratio 2.9-7.7 to 1
Samples were obtained from the following streams: (1) coal feed,
(2) limestone feed, (3) bed materials, (4) no. 1 cyclone catch, (5) sludge
from stack scrubber, (6) stack filtered gas, (7) stack particulates > 2.3
micron, (8) stack particulates < 2.3 micron, (9) stack hydrocarbons
adsorption column, and (10) stack volatile metals, impingers. Some pre-
liminary results of this program are presented in Table 2. These data
were intended to be used only for the purpose of evaluating the sampling
and analysis techniques and were not for statistical evaluation or direct
comparison with other fluidized-bed data.
11
-------
To Scrubber
and Stack *
Gas-sampling I me
•To analyzers
'Secondary
cyclone
Cooling coil
"Primary
cyclone
i Top heat transfer
probe
^Cooling coil
Ash
Middle heat-transfer
probe
1=1
Distributor plate
Bottom heat-transfer
probe
'"Cool and limestone
injection
Air
FIGURE 4. SCHEMATIC DIAGRAM OF BATTELLE'S
FLUIDIZED-BED COMBUSTOR (15cm-6" in Diameter)
12
-------
TABLE 2. RANGE OF PRELIMINARY RESULTS OF COMPREHENSIVE
ANALYSIS - EMISSIONS FROM BCL 15-cm (6")
FBC Unit
Component
0 (%)
2
co2 (%)
CO
so2
NO
X
HC (ppm C)
HC1
HF
HCN
NH3
so3
Particulate
Loading
(mg/m3)
POM (mg/m3)
ppm (Except
Range
3.6
14.
790
700
350
85
37
0.08
0.07
1.8
0.14
1500
5
Where Indicated)
of Values
6.5
17.
- 2090
- 730
- 415
- 360
- 44
0.7
0.2
7.1
19
- 1640
- 72
13
-------
C. Pretreatment of Input Streams
Presently, naturally occurring limestone and dolomite are widely
used as SC>2 sorbents, and they have been shown effective. However, any
improvement on sorbent utilization will produce significantly favorable
impacts on FBC economics and environmental factors such as quantity of
solid residue. Pretreatment of the input streams is a part of the EPA FBC
program directly related to Control Technology Development and some pre-
liminary investigations are presently underway at Westinghouse, Argonne
and Exxon as part of their overall support studies programs.
Several experimental programs aiming at improving the sorption
efficiency of limestone and dolomite are being conducted by EPA con-
tractors. While optimization of the process conditions is being inves-
tigated, as discussed later, extensive fundamental studies concerning both
physical and chemical aspects of the sorption phenomenon—such as chemical,
physical and structural characterization of the sorbents, attrition be-
havior and kinetic studies—are also emphasized.
Pretreatment methods to maximize sorption of the limestone and
dolomite are being investigated and it has been suggested that calcined
limestone and dolomite possess greater sulfur oxide sorption capacity;
the effect is more pronounced for the pressurized systems. Experimental
studies conducted by Exxon, ANL and Westinghouse have confirmed the ad-
vantages of calcined sorbents.
An earlier study by PER showed that the addition of common salt
to the limestone bed had favorable effects on improving the S0_ sorption
capacity of the limestone. ANL is currently conducting a detailed inves-
tigation of the mechanism for the action of salt in order to promote its
practical application, particularly toward finding a less corrosive
additive. Use of such an additive could substantially reduce the amount
of solid waste from the process.
D. Modification of Process Conditions
A number of experimental process studies in support of the
Control Technology Development Objective of the EPA FBC program are
underway, and much valuable information has been generated by Exxon and
ANL. Major experimental equipment is located at Exxon and ANL, however,
laboratory-scale equipment is in use at Westinghouse and MIT. A Sampling
and Analytical Test Rig (SATR) is also planned to interact on these pro-
cess studies.
14
-------
Exxon is conducting a program in their 10-cm (4-inch) diameter
pressurized bench-scale fluidized-bed combustor and in the Miniplant
facilities. The Miniplant Includes a 31.75-cm (12.5-inch) diameter
pressurized combustor and a 20.32-cm (8-inch) diameter pressurized re-
generator. Successful operation of a 100-hour shakedown run and a 240-
hour continuous demonstration run for the combustor were completed during
the first half of FY 1976. A major portion of a combustor process varia-
bles study has been completed. The coupling of the combustor and the
regenerator in the Miniplant is in progress, and the total integrated
operation, with continuous circulation of solids between the combustor
and regenerator, is planned for 1977. A schematic diagram and a photo-
graph of the Miniplant are shown in Figures 5 and 6. ANL, in a project
co-funded with ERDA, is conducting laboratory and bench-scale work, which
includes testing on their 15.24-cm (6-inch) diameter pressurized combustor
and 11.43-cm (4-1/2-inch) diameter pressurized regenerator.
SO,, Emission and Sorbent Requirement
Effective S0» control has been recognized as one of the most
important advantages or the FBC process. It is well known that the S02
emission from FBC depends on many process conditions such as sorbent/coal
feed ratio, sorbent type, temperature, pressure, gas velocity, bed height,
and sorbent particle size. Therefore, EPA's emphasis has been on the
effects of the process variables as they relate to S0~ control; sorbent
utilization efficiency and optimum operating conditions.
Following shakedown of the Miniplant, Exxon conducted a syste-
matic process variable study to investigate the effect of sorbent-type
Ca/S ratio and temperature on S02 removal in pressurized FBC systems.
Testing was also completed on the bench-scale combustor. The data from
this study is shown in Figure 7. It was observed that the S0? removal
ability of dolomite was unaffected by temperature, while higher tempera-
ture operation (e.g., 930 C) greatly improved the SO- removal ability of
limestone. The improved limestone utilization efficiency is attributed
to the calcination of limestone at higher temperature.
Based on the results obtained, sorbent requirements for a once-
through pressurized FBC system are predicted as shown in Table 3. Although
a significantly higher Ca/S molar ratio is required for limestone than for
dolomite, the sorbent requirements are roughly the same on a weight basis.
NO Emissions
Past studies have shown that the NO emission from FBC is gen-
erally lower than that from a conventional coal-fired boiler system.
Also, an increase in operating pressure significantly reduces the NO
emission for FBC. Significant NO data were obtained from Exxon's M?ni-
plant, BCL's 15-cm (6-inch) atmospheric unit and ANL's 15-cm (6-inch)
15
-------
ORIFICE
COOLINC
WATER
CITY
WATER
MAIN
AIR
COMPRESSOR
(1400 SCFM
"150 PSIC)
LIQUID FUEL
STORAGE
FIGURE 5. EXXON FLUIDIZED BED COMBUSTION MINIPLANT
-------
FIGURE 6. EXXON FLUIDIZED BED COMBUSTION MINIPLANT
17
-------
1600
Miniplant Data
1400
Coal: Champion Coal (2.2% S)
Limestone: Grove Limestone
Dolomite: Pfizer Dolomite
Source: Exxon Research & Engineering Company
1200
1000 -
.2
UJ
S
800 -
600 -
400 -
200 -
1234
Ca/S Molar Ratio
FIGURE 7. COMPARISON OF THE CORRELATIONS OBTAINED
FOR DOLOMITE AND LIMESTONE
18
-------
TABLE 3. SORBENT REQUIREMENT FOR PRESSURIZED FBC (ONCE-THROUGH)
Coal
Sulfur
(%)
2.0
3.0
4.0
5.0
Retention
Level ,.*
Required (%) <• '
59
73
79
84
Ca/S (mole/mole)
Limestone
1.3
2.1
2.75
3.25
Dolomite
0.8
1.05
1.18
1.3
Sorbent/Coal Wt. Ratio
Limestone
0.082
0.198
0.344
0.51
Dolomite
0.102
0.195
0.292
0.4
(1) Based on current EPA emission standard: .51 ug/J (1.2 Ibs SO7/million
Btu) .
Source: Exxon Research and Engineering
19
-------
pressurized unit during 1976. Shown in Figure 8 is the correlation of
NO emission and excess air from Exxon's study. The data indicate that NO
emissions will increase with increasing excess air but not exceed the x
current EPA standards. Under a normal operating condition of 15 percent
excess air and 10 atmospheres, the NO emissions are equivalent to 0.09 yg/J
(0.2 Ibs N0x/million Btu). This emission rate is significantly less than
the current EPA standard of 0.3 yg/J (0.7 Ibs NO /million Btu).
X
ANL's results of 0.07-0.09 yg/J (.15-.2 lbs/106 Btu) agreed
closely with Exxon's data and preliminary results from the comprehensive
analysis of BCL's 15-cm (6-inch) unit are also in good agreement (0.14 yg/J
or 0.3 lb/10^ Btu) at approximately 20 percent excess air.
A fundamental study on NO formation and control is being con-
ducted at MIT under EPA sponsorship. The objectives of this study are:
(1) to develop a model to predict NO emissions from FBC at atmospheric
and elevated pressure, (2) to provide physical-chemical input parameters
for the model, (3) to provide information for the development of new con-
trol technology and (4) to test the model over a wide range of significant
operating variables by comparing predicted data with experimental data.
Particulate Emissions
Particulate emissions from FBC of coal have been a major concern
from both environmental and engineering standpoints. Past studies have
confirmed that the particulate emissions are affected by many factors, such
as the characteristics of feed coal and sorbent, FBC geometry, heat trans-
fer surfaces, operating conditions, and the design of cyclones, etc.
Several projects on particulate emissions and controls have been conducted
by Exxon, Westinghouse and ANL. It is recognized that further development
of particulate control technology is imperative (e.g., high efficiency
cyclones, electrostatic precipitators, and granular bed filters). Support-
ing this finding are recent measurements from Exxon Miniplant operation
which indicate that the particulate loading in the flue gas leaving the
final cyclone was no less than 0.3 grams per standard cubic meter (0.13
grains scf). In some cases the particulate loading was as high as 2.8
grams per standard cubic meter (1.26 grains/scf). These particulate
emissions are unsatisfactory when compared to the current EPA emission
standards of 0.09 grams per standard cubic meter (0.04 grains/scf). These
emissions are also excessive for a stream being fed to a turbine as is
contemplated for pressurized FBC.
As FBC processes develop, particulate emission is one area
which must be carefully monitored to ensure that proper control techniques
are applied as necessary to eliminate significant environmental impact.
20
-------
ED
CM
O
0.8
0.61
EPA EMISSION STANDARD
MINIPLANT
BATCH UNIT
INERT BED
Source: Exxon Research & Engineering Company
I I I I L
40
60 80
EXCESS AIR (%)
100
120
140
FIGURE 8. NO EMISSIONS
-------
Alternative Sorbents
Although naturally occurring limestone and dolomite have been
shown to be effective sulfur dioxide sorbents, a few problems—such as
high sorbent requirement, loss of reactivity upon regeneration and
cyclic use, and unsatisfactory physical integrity—are associated with
their use. While methods of improving the limestone and dolomite utili-
zation efficiency are actively being studied, feasibility studies em-
ploying alternative sorbents which can eliminate or reduce the above-
mentioned problems are being conducted by several EPA contractors.
ANL is currently conducting a laboratory-scale study on syn-
thetic sorbents. The synthetic sorbents are prepared by impregnation
of a porous support material (e.g., alumina) with an active metallic
oxide (e.g., CaO, SrO, BaO, Na_0, and K-0, etc.). Preliminary studies
have concluded that the synthetic sorbents possess significantly superior
desulfurization and regeneration reactivities than limestone and dolomite.
It appears that CaO impregnated in alumina is currently the best choice
among those sorbents being studied. Further studies on improving the
physical integrity (attrition resistance) and the cyclic-use capability
of the sorbents are in progress.
In addition, Westinghouse Research Laboratory has completed an
initial evaluation of many possible alternative SO- sorbents based on con-
siderations of thermodynamic feasibility, physical properties, heat
balance, material balance, cost and availability. A preliminary study has
identified 14 sorbents potentially acceptable for atmospheric FBC and 11
sorbents for pressurized FBC. An experimental study to verify the appli-
cability of these candidate sorbents is currently in progress.
Trace Element Emissions
Inorganic trace elements such as mercury, lead, and beryllium,
emitted from fossil-fueled power plants, incinerators, and industrial
sources are receiving increased attention as potentially dangerous air
pollutants. The process of coal combustion releases trace elements to
the environment as vapors and/or in association with particulate emis-
sions. Although a substantial fraction of the trace elements present in
the coal during combustion is retained with the flyash removed by emission
control devices, significant quantities of trace elements (such as mer-
cury) may still be emitted as vapors or in association with submicron
size particles that are not efficiently removed by present-day devices.
A brief summary of work on trace elements emissions follows:
22
-------
At ANL, solids from the experiments conducted
with the 15-cm (6-inch) diameter pressurized
combustor were analyzed for trace elements
employing primarily neutron activation and to
a lesser degree, atomic absorption, fluori-
metry and specific ion electrode methods. The
gases were analyzed for mercury and fluorine.
Selected results of these analyses, presented
in Table 4, show that most elements are vola-
tilized to a lesser degree in FBC than in con-
ventional combustors. This is expected because
the bed temperature in FBC is lower (1600 F)
compared with 2800 F in conventional combustors.
However, mercury, being low boiling, appears
to volatilize about the same in both systems.
Exxon studied trace element retention in a 10-
cm (4-inch) diameter PFBC bed, and their results
agreed generally with the ANL data (Table 4).
Exxon employed the neutron activation method
of analysis.
Spark source mass spectrometric (SSMS) analy-
sis of the solid samples from the Battelle 6-
inch FBC unit indicated emission levels for Hg ,
Br, Pb, Sc, and K compared to those from other
FBC units (see Table 4). On the other hand,
the F and As levels were comparable to
those for conventional fired units. The remain-
ing elements were found to be generally at higher
levels than those observed in the other combustion
units. The data on these elements are suspect
due to the low accuracy of the SSMS method and
the experiment was not designed to obtain an
accurate mass balance.
Westinghouse provided thermodynamic projections
of trace element emissions which indicated that
Hg should volatilize and not condense. This was
confirmed by experimental data at Exxon and ANL.
Thermodynamics also predicted that several volati-
lized elements, such as Be, F, and Pb, can con-
dense as sulfates and chlorides if these anions
are present in sufficient amounts.
Other Pollutants
There are other compounds which will receive attention in the
EPA FBC program, as indicated in the previous discussion of "Comprehen-
sive Analysis". These other compounds include: gaseous and solid organic
compounds; and a variety of inorganic gaseous compounds, such as SO-,
gaseous sulfides and disulfides, NH^ cyanides, and gaseous chlorides and
23
-------
TABLE 4. PROJECTED STACK EMISSION OF SELECTED TRACE ELEMENTS
FROM CONVENTIONAL AND FLUIDIZED-BED COMBUSTORS
EXPRESSED AS A PERCENTAGE OF THE ELEMENT ENTERING
THE SYSTEM
Element
Mercury
Fluorine
Bromine
Arsenic
Lead
Beryllium
Scandium
Chromium
Cobalt
Sodium
Potassium
Iron
Manganese
Conven t ional
Combustion ^a)
90
90-100 (estimated)
100 (estimated)
50-60
0-60
No Data
10
0
10-20
20
30
0
0
Fluidized-Bed
ANL(a)
80
40
65-82
15
0-20
20-40
0-3
25
0-20
4-5
0-10
0
0
Combustion
Exxon (b)
No Data
No Data
79
14
No Data
No Data
15
0
No Data
12
25
20
4
BCL
75
98
90
59
21
98
0
(d)
(d)
(d)
25-54 «>
(d)
(d)
(a) Source: Argonne National Laboratories.
(b) Source: Exxon Research and Engineering.
(c) Source: Battelle-Columbus Laboratories
Spark Source Mass Spectometer Data (SSMS)
(d) Data Suspect Dut to Accuracy Limitations of SSMS
24
-------
fluorides. In their preliminary environmental assessment, GCA estimated
the possible emissions of such pollutants from FBC systems, based upon
available data, thermodynamic considerations and chemical experience
(see Table 5). Battelle is continuing this investigation as part of its
FBC environmental assessment effort. In general, it is concluded that
further data are necessary before definitive conclusions can be drawn
concerning the emissions of these pollutants from FBC.
During the 240-hour run of the Miniplant combustor, Exxon
measured SO, levels in the flue gas ranging from 0 to 94 ppm, with values
generally averaging about 5.5 ppm. The few high measurements of SO, are
considerably greater than the levels from conventional combustors (about
20 ppm). The preliminary results of comprehensive analysis on the
Battelle 6-inch I.D. atmospheric unit show an SO, level of about 20 ppm
in one run. These results are not conclusive; tnere is some concern
that the few high level data points may be the result of sampling error
or conditions, and this possibility is being investigated. The tempera-
ture of FBC is about the same as commercial sulfuric acid processes in
which S02 is oxidized to S03 and this may explain the higher levels.
Further evaluation of these results and more comprehensive investigations
are required to establish whether SO, emissions from FBC is a problem.
E. Add-On Controls
The development and testing of add-on controls is an important
part of control technology development. Control technology will be an
important factor in the ultimate commercialization, acceptance, and en-
vironmental aspects of FBC.
Several programs are currently underway which demonstrate
laboratory and practical applications of control technology. The prin-
cipal thrust of these studies at this time is on particulate control,
since particulate control is an identified need for both atmospheric
and pressurized FBC systems. Neither type of FBC system can meet the
current EPA New Source Performance Standard for large coal-fired boilers
(0.04 ug/J or 0.1 lb/10° Btu) without some control device in addition to
conventional cyclones. Control technology for other pollutants will be
developed as the need is identified.
Mobile Control Devices
EPA has developed mobile test control devices including a fabric
filter, a scrubber and an electrostatic precipitator. These units are
mounted on 12-meter (40 ft) vans and will be tested on appropriate avail-
able atmospheric-pressure FBC units as soon as practical. They will also
be tested on conventional combustors and other industrial emission sources
in order to define recommended control devices.
The mobile devices have been designed for a wide range of oper-
ating conditions. The capacity of each device is given in Table 6. For
25
-------
TABLE 5. ESTIMATED GAS PHASE (STACK) EMISSIONS
OF POTENTIAL POLLUTANT SUBSTANCES FROM
FBC
Estimated Stack Gas
Substances Concentration
HF, HC1, CH,, C?H,, C,H,, 1 ppm
HCN, NH , (CN),7 ILS, COS,
H7SO,, H,SO_, HNO.,7 Be, F,
CI, Na. J
Diolefins, aromatic hydro- 1 ppb
carbons, polynuclear aromatic
hydrocarbons, phenols, azo-
arenes, As, Pb, Hg, Br, Cr.
Carboxylic acids, sulfonic 0.1 ppb
acids, polychlorinated bi-
phenyls, alkynes, cyclic
hydrocarbons, amines, pyri-
dines, pyrroles furans, ethers,
esters, epoxides, alcohols,
ozone, aldehydes, ketones,
thiophenes, mercaptans
* Estimates are based on thermodynamic considera-
tions and chemical experience. These estimates
should be good to within an order of magnitude.
Source: GCA Corporation
26
-------
TABLE 6. CAPACITIES OF EPA MOBILE CONTROL DEVICES
Electrostatic
Precipitator
Actual volume handled,
m^/mln (cfm)
Maximum design temperature,
C (F)
Negative pressure than can
be accommodated by on
trailer blower, kPa (in H20)
Available ducting length,
m (ft)
84.95
(3000)
482.2
(900)
-4.9
(-20)
30.5
(100)
Bag
Filter
0.74-8.50
(26-300)
132.2
(270)*
-7.3
(-30)
—
Wet
Scrubber
8.50-14.16
(300-500)
371.1
(700)
-7.3
(-30)
—
* 143.3 C (290 F) is probably acceptable, higher temperatures must be
reduced by dilution with fresh filtered air.
operation, a slip stream from the stack gas is ducted to each of the three
devices which are mounted on the vans. The operating parameters for each
device can be varied to determine the optimum performance obtainable by
that collection process and the design parameters that will provide this
optimum.
Sampling and Analytical Test Rig
An FBC Sampling and Analytical Test Rig (SATR) is being designed
and built for EPA by the Acurex Company, Aerotherm Division. The SATR
will be located at RTF, N.C. and be used for a variety of studies including
add-on control devices. Some of the programs currently anticipated are (1)
evaluation of conventional electrostatic precipitators and bag filters,
(2) evaluation of high-temperature particulate control devices, (3) NO
emission studies, (4) NOX control by staged combustion, and (5) NOX con-
trol by ammonia injection. The anticipated operating ranges are (1) coal
feed rate of 10 to 50 kg/hr (22 to 110 Ib/hr), (2) sorbent feed rate of
0 to 25 kg/hr), (3) excess air of 10 to 300 percent, (4) bed temperature
of 750 to 1100 C (1380 to 2010 F), and (5) fluidizing velocity of 1 to 5
m/sec (3 to 16 ft/sec).
Particulate Control Test Facility
A test .facility has been designed by Westinghouse to study par-
ticulate control at high temperature (800-900 C, 1472-1652 F) and elevated
pressure (1500 kPa, 216 psi). The facility will produce a simulated flue
gas flow of up to 14.2 m^/min (500 ft3/min) at high temperature and
27
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pressure to test selected control devices. The system is designed to
generate dust loadings up to 57.5 gm/m3 (30 gr/scf) and to measure effi-
ciencies up to 99.99 percent. Specifications and design drawings have
been completed and installation will be started in 1977.
Miniplant Ducon Filter
A granular-bed utilizing Ducon filters has been designed by Exxon
for particulate control at their Miniplant. Additional particulate clean-
ing is required because the two stages of cyclones on the Miniplant have
reduced particulates to no less than 0.3 g/std m3 (0.13 gr/scf) which is
above the New Source Performance Standard.
The device consists of a steel shell, 2.44 m (8 ft) in diameter,
and 3.66 m (12 ft) tall, rated at 1138 kPa (165 Psi) at 760 C (1400 F).
It will be lined with 12.70 can (5 in.) of insulating refractory. Four
parallel filter tubes with about 10 elements in each tube will be in-
stalled. Three tubes will be of the Ducon design and one an Exxon design.
The Ducon design backflushes the filter with a short high pressure (2068
kPa, 300 Psi) pulse without disconnecting the filter from the system. The
Exxon filter disconnects a tube out from the system and fluidizes the
granular bed with a reverse gas flow. About 276 kPa (40 Psi) over system
pressure is needed. Figure 9 shows the basic features of the operation
of the device.
Fabrication and installation of the filter unit is well underway
and shakedown operation and initiation of a test program to define the
performance of the device will take place in 1977.
Regeneration of Sorbent
Experimental studies on regeneration of limestone and dolomite
were conducted mainly at Argonne and Exxon. Currently, the one-step
reductive regeneration process is being actively investigated by both
organizations. This process regenerates the spent, sulfated SO. sorbent
by the reaction:
CO C°2
CaS°4 + H° = Ca° +H20 + S02
The Argonne program investigated regeneration at essentially
atmospheric pressures, and involved treatment in the bench scale regenera-
tor vessel of batches of sulfated sorbent prepared previously in the
bench combustor. The Exxon program will be directed towards regeneration
at elevated pressure; the Miniplant has the capability to continuously
circulate solids between the combustor and the regenerator.
28
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Ducon Granular Bed Filter
Inlet
Clean
Gas
Outlet
Filter
Element
Collected
Dust
Outlet
Filter Element
Outer
Screen
Granular
Bed
Inner
Screen
Collection Cycle
Dust Laden i
Gas
Clean Gas
Cleaning Cycle
Collected
Dust
.*' (
Purge Gas
-Fluidized
Granules
F1GUKE 9. DUCON GRANULAR BED FILTER
29
-------
Some of the typical operating conditions are:
ANL Exxon Miniplant
Regenerator Size 4-1/2" diameter 8-1/2" diameter
Reductant Coal Natural Gas
Temperature (C) 1100 (2012 F) 1100 (2012 F)
Pressure (kPa) 153 (22 psi) 1000 (145 psi)
S02 Concentration in Off-gas 8.5 3
(% wt basis)
ANL's work has demonstrated that partial combustion of coal can
be used as the source of reducing agent. Sulfated Tymochtee dolomite and
Greer limestone have been successfully regenerated. Parametric studies
revealed that the extent of regeneration decreased with decreasing solid
residence time at all temperatures and increased with increasing regenera-
tion temperatures. The SO- concentration in the off-gas increased with
increasing regeneration temperatures and with decreasing pressures. As
high as 9 percent SO- in the off-gas has been obtained and this concentra-
tion is high enough for recovering the sulfur as sulfuric acid.
The technical feasibility of cyclic use of sorbents was demon-
strated by ANL in a 10-cycle, batch combustion/regeneration experiment.
Encouraging results were obtained. In each combustion step, Arkwright
coal was combusted in a bed of Tymochtee dolomite at a pressure of 810kPa
(117 psi) and a bed temperature of 900 C (1652 F). The regenerator was
operated at 153 kPa (22 psi) and 1100 C (2012 F). The reactivity of the
Tymochtee dolomite decreased linearly in each cycle. It was calculated,
based on this data, that, in a continuous combustion/regeneration system,
fresh sorbent would have to be added at a calcium to sulfur mole ratio of
0.35 to meet the EPA New Source Performance Standard of 1.2 Ib S02/106 Btu
with the 2.8 percent sulfur Arkwright coal.
A major effort at Exxon has been concentrated on the operation
of the Miniplant regenerator. Several shake-down tests with the regenera-
tor operated in batch mode (uncoupled with the combustor) have shown
satisfactory performance of the regenerator. Coupling of the combustor
and the regenerator in the Miniplant is currently underway.
Other Work
In addition to the particulate control work being conducted as
a direct part of the FBC program, EPA is conducting a broad program aimed
at developing, and at understanding the mechanisms of, particulate control
technology.
30
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F. Solid Waste Disposal
Extensive investigations on the FBC solid waste have been
started only recently. The solid residue from FBC is an area of major
environmental concern. The residue studies are in support of the control
technology development objective of the EPA program.
Spent sorbent and coal ash are constantly withdrawn from the
fluidized bed and can be immediately discarded (once-through), or the sor-
bent may be separated from the ash and reused after a regeneration process.
Even with regeneration, the sorbent material eventually becomes less
reactive and a portion must be discarded. The solid waste residue must
be discarded in an environmentally acceptable manner to avoid problems
from leaching, dusting, runoff, air pollution, and water pollution.
The EPA FBC solid residue program consists of projects with
Ralph Stone and Company, Westinghouse Research Laboratories and the
Tennessee Valley Authority (TVA). In addition, ERDA is sponsoring, or
has sponsored, programs in the area of residue utilization with the
Department of Agriculture, IU Conversions Systems, British Coal Utiliza-
tion Research Association (BCURA), Virginia Polytechnic Institute (VPI),
and Pope, Evans, and Robbins (PER). The early efforts have been valuable
in pointing out the direction for detailed laboratory and field investiga-
tions.
Liquid wastes from FBC have not been identified as a significant
environmental problem except as leachate water from solid waste disposal
beds. If other problems related to liquid wastes are identified as a
result of the Environmental Assessment Program, provisions will be made
for detailed investigation.
Scope of Current EPA Solid
Waste Programs
The scope of current programs in FBC solid waste includes:
(1) characterization of solid waste materials resulting from variations of
the FBC process and input materials; (2) laboratory and field studies to
identify solid leaching properties and the effects of long-term exposure
of solid waste and solid waste by-products to the environment, (e.g., lysi-
meter tests, shake tests and field study planning); (3) laboratory studies
of physical and chemical treatment of solid wastes to reduce the environ-
mental impact upon disposal; (4) laboratory and marketing studies of the
potential for utilization or for manufacturing marketable products from
31
-------
solid waste material; and (5) environmental impact from disposal by
methods other than conventional landfill (e.g., ocean disposal, land-
spreading, acid-mine treatment, and flue-gas desulfurization sorbent).
Characterization of Spent-Bed Materials
The detailed characterization of the spent-bed (waste) materials
is important to the overall FBC program in two major ways. First, as a
means of understanding the basic mechanisms of sulfur removal in the corn-
bus tor and reactions taking place in regeneration processes and, second,
to determine the elements, compounds, properties and physical structures
of materials which could have potential adverse environmental impact.
Westinghouse, Argonne, Ralph Stone and Company and TVA have planned
characterization efforts aimed at determining the physical and chemical
properties of FBC waste material.
Many analytical techniques are being used in the characterization
study including: classical wet chemistry, x-ray diffraction, electron
microscopy, scanning electron microscopy, electron microprobe, differen-
tial and gravemetric thermal analysis, atomic absorption and mass
spectrometry. For example, Argonne has analyzed regenerated and sulfated
dolomite particles by electron microprobe and has determined that a
radial variation exists in the sulfur content which depends on the sulfa-
tion or regeneration time. In the sulfation experiments, a shell of sul-
fate is formed on the outer surface of the particle which moves toward
the center of the particle as the sulfation time is increased.
In regeneration processes, it appears that a two-step reaction
takes place; an early stage where the primary regeneration-reaction zone
moves radially into the sulfated particle, leaving some residual sulfur
behind the advancing zone, and a second (slower) stage which will remove
most of the residual sulfur. In a commercial FBC regeneration process,
in which the solids residence time would be short (high solids throughput
rate), probably only the first (rapid) stage of regeneration would occur.
Hence, most but not all of the sulfur could be removed.
The spent-bed (solid waste) material from the FBC of coal will
consist primarily of varying ratios of calcium sulfate, calcium oxide,
coal ash and smaller amounts of other compounds and trace elements depend-
ing on the initial compositions of the coal and sorbent and the operating
conditions of the FBC unit. Magnesium oxide will be present if dolomite
is used as the sorbent and the composition of the spent-bed material will
also vary if regeneration processes are used. Withdrawal point, mixing
of cyclone ash with the spent bed, and the Ca/S ratio will also be factors
affecting the ultimate composition.
Table 7 lists some typical examples of sorbent and coal input
and output compositions which might be expected for FBC combustors. It
must be remembered that compositions of naturally occuring materials such
as coal, limestone and dolomite will vary considerably from point to point
in a deposit and values must be averaged. The values in Table 7 are pre-
liminary and detailed characterization will depend on future work involving
waste material which is typical of commercial FBC units.
32
-------
OJ
o>
TABLE 7. EXAMPLES OF TYPICAL COAL AND
(MAJOR CONSTITUENTS) FOR FBC
SORBENT INPUT AND OUTPUT COMPOSITIONS
COMBUSTORS (WEIGHT PERCENT)
Compound
CaSOA
CaO
CaCOj
MgO
Fe203
Si02
A1203
C
s
H2
°2
N2
H20
Ash
Other Trace
Elements &
Compounds
Coal,
Pittsburgh
08 Pfizer^1) Coal Ash^1' #1359
— — — 43.7
3.8 28.9 1.9 54.0
92.3
0.3 22.9 0.6 (a)
0.1 0.2 27.3 (a)
0.5 0.5 45.3 (a)
— 21.2 (a)
—
(b)
—
—
__
47.4(c;
—
— 2.3
Dolomite,
01337
31.5
30.2
—
36.7
(a)
(a)
(a)
—
(b)
—
~
—
—
~
1.6
Pressurized FBC Waste^3)
Limestone, Dolomite,
01359 01337
60.6
37.4
—
(a)
(a)
(a)
(a)
--
(b)
—
--
—
—
—
2.0
64.1
6.6
—
22.9
(a)
(a)
(a)
—
(b)
—
~
—
—
~
1.2
Sources:
(1) Battelle's Columbus Laboratories, open literature.
(2) Exxon Research and Engineering.
(3) Westinghouse Research Laboratories.
(a) Included in other.
(b) Included in CaSO^ value.
(c) H20 + C02
-------
Environmental Impact of Disposal
One of the primary aims in the EPA solid waste disposal program
is to determine the degree of environmental impact from the disposal of
large quantities of FBC waste material. Work in progress includes analysis
of leachate from residues generated by currently operating experimental
units (e.g., Exxon MinipIant, PER, ANL, etc.). Much of the preliminary
information has been obtained from simple shake tests and a comparison
with leachates from flue gas desulfurization (FGD) waste. FGD waste has
many similar characteristics to that obtained from FBC, except it is
usually disposed of as a sludge, whereas fluidized-bed residue is a dry
solid. Table 8 lists some preliminary comparisons of trace elements from
FBC ash and spent stone leachates with ash ponds and FGD sludge liquors/
supernatants. There are indications that there may be some problems
associated with trace elements in leachates, however this must be con-
firmed when the results from large-scale lysimeter tests and further shake
tests are available early in 1977.
Ralph Stone and Company is currently investigating residue
leachate by the use of column lysimeters simulating eight environments
thought to be representative of typical disposal sites. These are: lime-
stone quarry, dolomite quarry, coal mine, ocean (shore landfill), sanitary
landfill and three standard soil environments. Stone is also planning
field investigations when sufficient quantities of residue become available
for large scale testing.
One of the problems receiving considerable attention is the
defining of standardized shake, lysimeter and leaching tests. Standardized
tests are essential to allow comparison of data between laboratories and
to provide quick, inexpensive methods to evaluate the effects of process
variations on the properties of the waste materials. Westinghouse, Ralph
Stone and TVA are providing input to the solving of this problem and it is
expected that standard methods will be available and used in 1977.
Westinghouse has prepared a preliminary estimate of the environ-
mental impact from land disposal of spent sorbent and ash as projected
from current experimental data (Table 8) . Indications are that landfill
disposal of spent stone will not cause problems which cannot be solved
using current control technology. This must be confirmed as more data
becomes available on leachates from residue representative of that obtained
from large-scale FBC. Emphasis during the early stages of the FBC solid
waste program will be on once-through, throw-away processes, since these
will be the first to reach commercial utilization. Regeneration processes,
as a method of reducing the solid waste burden, will receive greater em-
phasis later.
34
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TABLE 8. TKACE METALS IN ASH, FGD SLUDGE POND, LIQUORS/SUPEBNATANTS, AND
FBC ASH AND SPENT STONE (EXCEPT pH, CONCENTRATIONS IN PPM)
Ash Fond
PH
Antimony
Arsenic
Barium
Beryllium
Boron
Cadaium
Chromium
Copper
Fluorine
Germanium
Mercury
Lead
Manganese
Molybdenum
Nickel
Selenium
Vanadium
Zinc
Samples
Mean
10.9 (a)
0.017
<0.036
<8.24
0.0011
3.66
<0.0031
<0.267
<0.031
4.88
<0.01
0.0033
0.0088
<0.002
0.169
«0.037
<0.10
<0.12
<0.055
5
High
12.5
0.33
0.084
40.
0.003
16.9
<0.01
1.0
0.092
17.3
0.01
0.015
0.024
<0.002
0.69
<0.05
0.47
<0.2
<0.19
FGD Sludne
Mean
8.9
0.021
<0.011
<0.866
0.002
3.286
<0.0012
<0.0043
<0.027
15.93
<0.013
0.008
0.005
<0.002
0.066
<0.05
0.023
<0.1000
<0.0270
5
Pond
High
9.7
0.035
0.03
2.0
0.002
6.3
0.002
0.011
0.045
31.5
0.02
0.001
0.0061
<0.002
0.075
<0.05
0.045
<0.1
<0.052
FGD Sludge
Mean
7.4
-
<0.068
-
<0.041
-
0.038
<0.087
<0.070
-
-
<0.045
0.072
-
-
-
<0.75
-
0.14
5
liquors FBC Ash Leachates
High Mean High
9 11.4 12.2
_
0.20 0.68 2.5
_ '
0.18
0.39 0.61
0.10 0.0025 0.01
0.21 HD <0.1
0.20
-
_
0.12 3.8 6.2
0.18 1.3 2.5
_
9.7 17
_
2.5
_
0.30 0.028 0.08
4
FBC Spent Stone
Leachates
Mean
12.16
<0.3
5.0
-
<0.01
0.37
<0.1
-------
TABLE 9. ENVIRONMENTAL IMPACT OF SPENT SORBENT FROM FLUIDIZED BED COAL COMBUSTION PROCESS
US
Sample
Spent Sorbent
(bed material )
Flyash
(fines of sorbent/ash >
Process
Pressurized System
once -through
Pressurized System
once - through
Atmospheric System
once -through
Pressurized System
once -through
Mixture of Spent ! Pressurized System
Bed Sorbent and Flyash once - through
Gypsum
Natural
Sorbent
Limestone
Dolomite
Limestone
Limestone
Limestone
Environmental Parameters
Heat
Release
ND <0. 2°C
ND <0. 2°C
ND<0.2°C
ND <0. 2°C
ND <0. 2"C
ND
-------
Westlnghouse also is currently investigating low temperature
processing of waste material, prior to disposal, which has the potential
of reducing leachate problems significantly.
Table 10 is an example of preliminary FBC leachate concentration
estimates compared to estimates from landfill leachate, gypsum leachate,
and FGD supernatant concentrations and proposed EPA and World Health
Organization water supply intake criteria. Data such as presented in
Tables 8, 9 and 10 will be important for interpreting leaching results and,
initially, drinking water standards will be used as a guide to environ-
mental impacts. Ultimately, the MEG chart will be used to interpret the
data obtained from leachate testing and relate the results to health and
ecological effects.
Utilization and Marketing
There are several possible uses for spent bed material which
are currently being investigated. These include: landspreading, fer-
tilizer, ceramics, concrete, brick, plaster, acid mine treatment, road
deicers, FGD treatment, and land reclamation. Current indications are
that there is a definite potential for utilization which must be confirmed
by market and economic analyses.
Future Studies
In 1977, it is expected that detailed characterization of typical
residues from FBC will be completed. Westinghouse, Ralph Stone and TVA
will be involved in these studies which should ultimately define the limits
and variability of FBC waste materials and provide the information necessary
to determine potential environmental impact. Trace element determinations
will receive a high priority to insure that no potential harmful components
will be overlooked. Shake, column and laboratory leaching tests will be
standardized and used to screen residue for detailed analysis as necessary.
Ralph Stone and Company will plan for small-scale and large-scale field
tests of residue to be implemented as soon as sufficient quantities of
material become available. Sufficient information will have been obtained
to allow recommendations to be made for disposal sites or alternate dis-
posal methods. Utilization studies and market projections for potential
products from FBC waste will be essentially complete. Evaluation of
Westinghouse's low temperature processing of residue to reduce leachate and
environmental impact will also be completed.
The EPA FBC solid waste program is also directly related to the
environmental assessment program and to the ERDA program. Therefore, changes
and developments in the FBC process must be carefully evaluated with regard
to their effects on the environmental impact of FBC solid waste. Close
coordination with the ERDA development program is essential to identify and
minimize environmental impacts before commercialization of the FBC process.
37
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TABLE 10. COMPARISON OF FBC WASTE LEACHATE WITH SANITARY LANDFILL,
GYPSUM, AND FGD LEACHATE
oo
Proposed EPA and Sanitary FGD
WHO Water Supply FBC Waste Landfill Supernatant/
Intake Criteria Leachate Leachate Leachate
pH 5-9
TDS 500 (b)
S04~2 250
Ca 75
7-12 + *a^ 4-6 8-12 +
2000-9000 10,000-14,000 8000-10,000
1000-6500 400-650 3,000
300-6000-H- 900-1700 800
Iowa
No. 114
Gyps urn
^7.4
'x.lSOO
^600
(a) + indicates some data points of higher value were obtained but are not regarded as
representative.
(b) Values (except pH) in ppm.
Source; Compiled by Battelle from information supplied by: Westinghouse Research
Laboratories, Argonne National Laboratories, Pope Evans and Robbins, National
Research Development Corporation (BCURA), R. Stone and Company, Aerospace
Corporation, Battelle, and open literature.
-------
Additional problems associated with solid waste, not presently
known, will be identified as larger quantities of waste material become
available for detailed investigation.
G. Application Studies
Since FBC has the potential of being a less polluting and a
more efficient method of coal combustion, and because efforts to assess
its environmental impact should also be related to the factors which
affect its market penetration, EPA has participated in studies on FBC
applicability to industrial boilers. EPA also initiated (1) a study to
compare costs of alternate processes for coal combustion with reduced
pollution and (2) an assessment of the effect of experimental scale on
emissions from FBC units.
Application of FBC to Industrial Boilers
This program is jointly funded by FEA, ERDA and EPA with Exxon
as the contractor. The study has several objectives.
1. Determine the maximum, minimum and most likely
demand for industrial coal-fired FBC technology
considering cost, availability of fuel, and
other relevant factors.
2. Determine the anticipated reduction in national/
regional oil and gas consumption by the use
of coal-fired industrial FBC technology, both
for new units and retrofit of existing units.
3. Assess the economic Impact of widespread in-
dustrial application of the pertinent FBC
technology to all affected segments of the
economy .
4. Determine and define the specific technical
requirements for representative applications
of the pertinent FBC technology.
5. Assess the potential environmental impacts of
the above.
are:
The significant interim conclusions of the Exxon industrial FBC
(1) a good potential exists for use of FBC technology in the
<.*lB naoer petroleum refining/petrochemicals, primary metals and
fo indu^Scpossibly 3 x 10" Btu/year by the year 2000); (2) fluidized
bed Industrial boiler systems can be more economical than conventional
coal-rlred systems with flue gas scrubbing; (3) larger boilers (up to
9?n 000 lbfl/hr 113,400 kg/hr steam production) favor FBC since they are
Ute£ to be more c^mpactrtan conventional boilers and (4) to realise the
atove potentials, there is an urgent need to demonstrate the reliability of
39
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FBC technology on a reasonable plant scale. The study also confirmed
that emissions of S02 and NO from industrial fluidized bed boilers can
be reduced to levels below those specified in current Federal emission
standards. Particulate can also be reduced to these levels by the use
of control technology. The study is continuing and final conclusions
are yet to be determined.
Cost Comparison Studies
Under EPA sponsorship, TVA is conducting a study to compare the
projected capital and operating costs of commercial atmospheric- and
pressurized-FBC power plants with a conventional coal-fired power plant
employing FGD. The costs being used for atmospheric and pressurized FBC
systems were those developed by General Electric, Foster Wheeler and
Bechtel under the Energy Conversion Alternatives Study (EGAS) which is
jointly funded by NASA, ERDA, and NSF. Under the EPA-TVA study, GE is ex-
tending their previous cost estimates to include a conventional boiler
with a non-regenerative lime scrubber. The initial estimates (for a
roughly 800-MW system) show atmospheric and pressurized FBC to have some-
what lower costs of electricity than a conventional boiler with scrubber.
TVA is conducting parametric cost studies using the GE input. A final
report is scheduled for 1977.
Studies on Effect of Scale-Up
Dow studied the effect of experimental scale on the emissions
from FBC systems. Emissions data from 12 experimental FBC units of
different sizes were examined, and the available data were plotted in an
effort to determine the effect of scale-up. This technique did not lead
to any definite conclusions.
RELATIONSHIP OF THE EPA PROGRAM TO THE
DEVELOPMENT PROGRAMS
The major program in the United States for development of FBC
technology is presently being conducted by ERDA. The ERDA program
addresses the potential applications of coal-fired FBC in the electric
utility and the industrial sectors, and in commercial/residential community
usage. The Electric Power Research Institute (EPRI) is conducting a co-
ordinated program in FBC technology research and development, keyed to the
needs of electric utilities.
Development work is also being done outside the United States,
especially in the United Kingdom. Significant funding for the British
work is provided by ERDA and EPRI.
40
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ERDA Development Program
The ERDA program strategy is to continue work on research and
component development while proceeding to large-scale prototype develop-
ment. The development sequence of the ERDA program is based on a manage-
able scale-up program for both atmospheric and pressurized combustors.
This sequence consists of laboratory-scale testing and bench-
scale units (less than 1 ton coal/day) at ANL; process development units
(PDU, 1 to 10 tons coal/day) at PER for atmospheric and at Combustion
Power Company (CPC) for pressurized units; component test and integration
units (CTIU, 10 to 100 tons coal/day) planned at Morgantown Energy
Research Center (MERC) for atmospheric and at ANL and the International
Energy Agency (IEA) for pressurized units; pilot plants (100 to 1000 tons
coal/day) at Rivesville (30-MWe) for atmospheric and Curtiss-Wright
(13-MWe) for pressurized units; and demonstration plants (over 1000 tons
coal/day) which have not yet been designated. In addition to these units,
which are aimed primarily at utility applications, ERDA is cofunding a pro-
ject with the Department of Housing and Urban Development to design and
construct a modular integrated utility system (MIUS) using an atmospheric
fluidized-bed combustor to provide the total electricity, heat, air con-
ditioning, and hot and cold potable water requirements for housing com-
plexes. ERDA has also recently initiated eight projects for the design,
development, and construction of demonstration units for industrial and
institutional applications such as process steam, process heat, and space
heating. Table 11 gives an approximate schedule for these units.
Other fluidized-bed combustion activities include system studies
and system definition to provide a continually updated program objective
and to aid in projecting potential acceptability to industry; environmental
risk studies; technical risk studies; safety impact studies; and an energy
conversion alternatives study (EGAS). The EGAS is examining economic
and energy efficiency considerations of alternative schemes for generating
power including several schemes based on fluidized-bed combustors.
EPRI Development Program
The emphasis of the EPRI program is on aspects of FBC which are
of specific interest to utilities and encouraging boiler manufacturers to
participate in the development of fluidized-bed boilers. Since the EPRI
program is being conducted in a close relationship to the ERDA program, there
has been no need for EPRI to sponsor the construction of large-scale test
facilities. However, EPRI has sponsored studies on relatively large units
owned by others. For example, EPRI has sponsored process development studies
41
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TABLE 11. APPROXIMATE SCHEDULE FOR ERDA UNITS
Unit Size and/or
Designation(a)
0.5 MWe PDU
AFBC
1.0 MWe PDU
3.0 MWe CTIU
PFBC
30 MWe CTIU
PFBC
6.0 MWe CTIU
AFBC
Contractor and/or
Location
Pope, Evans, & Robbins
Alexandria, VA
Combustion Power Co.
Menlo Park, CA
Argonne National Lab .
Argonne , IL
Internatl. Energy Agcy.
Grimes thorpe, U.K.
Morgantown Energy Res .
Center
Approximate Starting Dates (fe)
Design Construction Operation
— — In operation
In operation
Mid '76 Mid '77 Late '78
Late '76 Mid '77 Late '79
Late '76 Late '77 Late '79
13.0 MWe Pilot
Plant, PFBC(d)
30.0 MWe Pilot
Plant, AFBC
MIUS PDU
AFBC (e)
MIUS Pilot Plant
Industrial and
Institutional
Applications ( f )
Morgantown, WV
Curtis-Wright
Woodridge, NJ
Pope, Evans, & Robbins
Rivesville, WV
Oak Ridge National Lab.
Oak Ridge, TN
Oak Ridge National Lab.
Oak Ridge, TN
Various^)
Late '76 Late '77
Late '79
In Progress Sept., '76
In Progress Late '76
Mid '78
Late '80
Late '77
Mid '81
Late '76<8) Late '77(g> Late '79(g>
(a) PDU is process development unit (1-10 tons coal/day), CTIU is component test and
integration unit (10-100 tons coal/day), pilot plant is 100-1000 tons coal/day, AFBC
is atmospheric pressure and PFBC is pressurized fluidized-bed combustor, MIUS is
modular integrated utility system. All are boilers except where noted.
(b) Approximate schedule as of May, 1976.
(c) Flue gas drives turbine. No heat transfer surfaces.
(d) Flue gas mixed with air heated in tubes to drive turbine.
(e) Air heated in tubes to drive turbine and provide heat and cooling.
(f) Aerojet Energy/Ideal Basic Industries to produce combustion gas for cement kiln;
Fluidyne Engineering/Owatonna Tool for hot process air heater; Battelle Memorial
Institute/Fluidized Combustion, Combustion Engineering/Great Lakes Naval Training
Center, Dow Chemical/Babcock & Wilcox, Zurn Industries/Burns & Roe, and Georgetown
University/Fluidized Combustion for boilers; Exxon for crude oil still.
(g) Earliest starting date of any of the projects.
42
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on a 3 x 3 ft (91 x 91 cm) atmospheric unit owned by Babcock and Wilcox
and will sponsor more such studies plus component tests on a 6 x 6 ft
(183 x 183 cm) Babcock and Wilcox unit which is under construction (to be
operable in Fall, 1977). Most pf the EPRI program is oriented toward
atmospheric boilers.
Specific studies sponsored by EPRI include investigations of
fluidization and heat transfer characteristics in cold model configura-
tions most likely to be used for utility boilers; engineering design,
evaluation, and economic studies on the application and retrofit of fluid-
ized-bed combustors and their components to utility boilers; studies related
to the selection and utilization of S02 sorbents; investigation of corrosion/
erosion problems and their elimination; studies on combustion characteristics
and carbon utilization; and Investigation of hot gas cleanup. EPRI is also
conducting studies on transportation, health effects, and environmental
effects which are applicable to all types of power plants and are not
specific to FBC systems.
International Development Programs
The EPA is monitoring closely international FBC activities which
are at various stages of development and are aimed at implementation of
processes that address specific and sometimes unique applications.
Pollution control is often a secondary reason for interest in
FBC in most countries. In the United Kingdom, organizations such as the
National Coal Board, National Research Development Corporation, Combustion
Systems, Ltd., Babcock and Wilcox, Ltd. (U.K), and Woodall Duckham (subsidiary
of Babcock and Wildox, Ltd.) have been and are developing processes for both
industrial and utility applications. British ceal is primarily low sulfur
and inert material or ash is generally used as the bed material. Lower
fluidizing velocities (2-8 fps or 60<-240 cm/sec) and, hence, smaller
particles are used by the British, so their units have physical and operat-
ing characteristics different from the U.S. units. Swedish organizations
have expressed Interest in commercial systems for applications such as
district heating. The Japanese are investigating applications to nonreactive
fuel utilization, i.e., coke breeze burning for steam and power generation.
Additional research is being conducted by West Germany (Bergbau-Forschung)
and India (Bharat Heavy Electricals).
Some existing units which have received attention are the Renfrew
boiler (Scotland), the Ignifluid boiler (France), and the Duklafluid boiler
(Czechosolvakia)- The Renfrew unit, built by Babcock and Wilcox (U.K.), is
the largest existing fluidized-bed boiler that is amenable to sulfur control
and was converted from a conventional boiler to a fluidized-bed unit with
a published capacity of 45,000 pounds of steam per hour. It has operated
at 20,000 pounds per hour and is currently being upgraded. The Ignifluid
and Duklafluid boilers are similar to each other and are not typical
fluldlzed-bed combustors as compared to most of those of interest in the
U.S. development effort. The fluidized zone acts as a reducing (fuel) gas
generator and there are no tubes in this zone. The fuel gas generated in
this zone plus unburned carbon is combusted in a regular boiler with second-
ary air supply.
43
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Significant units in the planning stage include a 30 MW, 10 atm.
steam generation-gas turbine demonstration project sponsored by the Inter-
national Energy Agency (IEA) of which the United States (ERDA) is a member
(other members are the United Kingdom and West Germany); a proposed project
on gas generation/hot gas cleanup/gas turbine pilot plant to be built by
Bergbau-Forschung of Essen, Germany; and a 25 MW district heating unit to
be built in Enkoping, Sweden. The IEA and German units should provide
significant inputs to the development and commercialization of pressurized
systems while the Swedish unit is quite versitile in being designed for
completely automated operation with a capability for fuel switching.
EPA Contributions to the Development Programs
The EPA program complements the ERDA technology development
program as well as the EPRI and International programs by,
Providing information on pollutant emissions,
Establishing environmental goals for the process,
Recommending best available control technology,
Recommending environmental standards,
Developing control technology,
Contributing to the ERDA process development studies,
Contributing to studies on economics and acceptability
of the process.
The contributions of the EPA program can be arranged according to key out-
puts which fall under environmental assessment or the control technology
development categories and which are given in Table 12 along with their
expected completion dates. Many of the EPA outputs will be available in
time to influence the design and construction of the ERDA units and data
from the subsequent operation of the ERDA units will be used to update the
EPA outputs.
The EPA program is being conducted in coordination with the FBC
technology development program being conducted by ERDA. Much of the EPA
testing (comprehensive analysis, control technology) will be performed on
ERDA units. ERDA will use EPA's pressurized FBC Miniplant for process
development studies. EPA and ERDA are co-funding the experimental work at
ANL and the industrial boiler applications study at Exxon,
Thus, the EPA program is an integral part of the development pro-
gram for fluidized-bed combustion in the U.S. By conducting the EPA program
in parallel with the technology development programs, any significant environ-
mental problems should become apparent during the early stages of development.
These problems can then be addressed at a time when choices can still be
made among alternative process variations in order to choose the more environ-
mentally acceptable ones. Such choices at the early stages of development
will avoid the expense and inconvenience of redesigning and retrofitting
large units after construction.
44
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TABLE 12. ANTICIPATED SCHEDULE FOR OUTPUTS OF THE EPA PROGRAM
Output Date
Environmental Assessment
Comprehensive analysis plan for existing units 7/76
Complete first version of Multimedia Environmental Goals Chart 3/77
Reports on environmental problems identified through eompre- 6/77
hensive analysis and biological screening tests 6/79
6/81
Design of phased test program for Rivesville unit 3/77
Preliminary recommendation to set standards for atmospheric
units based upon initial comprehensive analyses on Rives- 12/77
ville unit
Updated recommendations to set standards for atmospheric
units based upon further comprehensive analyses and control 17/78
device characterization on Rivesville and other existing
facilities
Manual of best available control technology for atmospheric 17/78
units based upon Rivesville and other existing facilities
Update of Multimedia Environmental Goals Chart 12/78
Updated recommendations of standards and updated technology
manual for atmospheric units based upon further comprehensive
analysis and control device characterization on Rivesville and 12/80
MERC, CTIU, and upon testing of second-generation control
devices
Initial recommendation to set standards for pressurized units
based upon initial comprehensive analysis and control device 9/81
characterization on Curtiss-Wright pilot plant and Argonne CTIU
Manual of best available technology for pressurized units based
upon control device characterization on Curtiss-Wright and 9/81
Argonne units, and upon high temperature/pressure device testing
Control Technology Development
Preliminary recommendations for testing particulate control 1/77
devices
45
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TABLE 12. (Continued)
Output Date
Control Technology Development
(Continued)
Complete initial sorbent precalcination tests on Exxon T,I->£.
Miniplant u/ 76
Initial schedule for control technology testing on PDU, CTIU, 6/77
and pilot-scale facilities ''
Initiate testing of Ducon filter on Miniplant 1/77
Initiate particulates control device testing on Westinghouse ,/7
test stand b///
Report on testing of solid waste disposal and utilization 19/77
methods 1////
Complete environmental testing of Miniplant combustor in once- 17/77
through sorbent operation
Initial report on control technology testing on atmospheric i?/7«
PDU and pilot facilities '
Complete first phase of particulates control device testing on
the EPA Sampling and Analytical Test Rig in support of other 7/79
control device testing projects
Updated report on control technology testing on .atmospheric PDU, 12/80
CTIU, and pilot facilities
Complete environmental testing of Miniplant combustor/ 6/81
regenerator system
Complete testing on control technology for atmospheric Indus- 6/81
trial boiler
Initial report on control technology testing on pressurized
PDU, CTIU, and pilot facilities
Complete testing of control technology for atmospheric utility
boiler
Update report on control technology testing on pressurized
PDU, CTIU, and pilot facilities
Complete testing of control technology for pressurized utility
boiler
46
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While the results of preliminary EPA investigations indicate
that FBC will not cause serious environmental pollution problems, the
emissions and effects of numerous potential pollutants have yet to be
studied and further analytical and experimental work is necessary to ensure
that adequate consideration has been given to all likely environmental
hazards.
The EPA is playing a significant role in ensuring that the FBC
systems that are developed to the commercialization stage are environ-
mentally acceptable with respect to both solid wastes and atmospheric
emissions. The rate of commercialization of the FBC process will be affected
by various engineering and economic factors including costs, efficiency,
application to specific needs, and system and components availability.
Close coordination of the EPA program with the technology development effort
will assure efficient integration of environmental considerations and will
increase the acceptance by potential FBC users.
47
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BIBLIOGRAPHY
Publications and Papers Related to the
EPA Fluid!zed-Bed Combustion Program
During June 30, 1975-June 30, 1976
Publications from the Fourth International
Conference on Fluidized Bed Combustion,
McLean, Virginia, December 9-11, 1975
Fennelly, P. F., D. F. Durocher, H. Klemm, R, R. Hall, "Preliminary
Environmental Assessment of Coal Fired Fluidized-Bed Combustion",
GCA Corporation.
Gordon, J. S., H. I. Abelson, and G. Erskine, "Plans for a Sampling and
Analysis Procedure Manual for the Environmental Assessment of FBC", The
MITRE Corporation.
Henschel, D. B., "The U.S. Environmental Protection Agency Program for
Environmental Characterization of Fluidized-Bed Combustion Systems",
Environmental Protection Agency.
Hoke, R. C,, "Emissions from Pressurized Fluidized-Bed Coal Combustion",
Exxon Research and Engineering Company,
Hubble, B. R., S. Siegel, L, H. Fuchs, and P. T, Cunningham, "Chemical,
Structural, and Morphological Studies of Dolomite in Sulfation and
Regeneration Reactions", Argonne National Laboratory.
Keairns, D. L., D. H. Archer, J. R. Hamm, B. W, Lancaster, E, P. O'Neill,
R. A. Newby, C, H. Peterson, C. C. Sun, E, F. Sverdrup, E. J. Vidt, and
W. C. Yang, "Systems Implications of Desulfurization by Limestone in
Pressurized Fluidized-Bed Combustion", Westinghouse Research Laboratories.
Montagna, J. C., J. F. Lenc, G. J. Vogel, G. Thodos, and A. A. Jonke,
"Bencn^Scale Regeneration of Sulfated Dolomite and Limestone by
Reductive Decomposition", Presented at the Fourth Inter^^°" f ?In 1975
ference on Fluidized-Bed Combustion, McLean, Virginia, December 9-11, 1975
Nutkis M. S., "Operation and Performance of the Pressurized FBC
Miniplant", Exxon Research and Engineering Company.
Ruth, L. A., "Regeneration of CaS04 in FBC", Exxon Research and
Engineering Co.
48
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Swift, W. M., G. J. Vogel, A. F. Panek, and A. A. Jonke, "Trade-
Element Mass Balances Around a Bench-Scale Combustor".
Snyder, R. B., W. I. Wilson, G. J. Vogel, and A. A. Jonke, "Sulfation
and Regeneration of Synthetic Additives".
Vogel, G. J., W. M. Swift, J. C. Montagna, J. F. Lenc, and A. A. Jonke,
"Recent ANL Bench-Scale, Pressurized-Fluldized-Bed Studies", Argonne
National Laboratory.
Publications from Fluidization Technology. Volume II.
D. L. Keairns, Editor. Proceedings of the International
Fluidization Conference, Pacific Grove, California,
June 15-20. 1975, Hemisphere Publishing Company,
Washington, 1976
Nack, H., K. D. Kiang, K. T. Liu, K. S. Murthy, G. R. Smithson, Jr., and
J. H. Oxley, "Fluidized-Bed Combustion Review".
Nutkis, M. S., "Pressurized Fluidized Bed Coal Combustion".
Ruth, L. A., "Combustion and Desulfurization of Coal in a Fluidized-Bed
of Limestone".
Other Publications and Papers
Abelson, H. I., W. Lowenbach, and J. W. Gordon, "Sampling and Analysis
Procedure Manual for the Environmental Assessment of FBC", to be
published in Analytical Methods for Coal and Coal Products, Academic
Press, 1977.
Fennelly, P. F., "Emission Estimates of NOX and Organic Compounds from
Fluidized-Bed Combustion", Proceedings of the International Conference
on Photochemical Oxidants and Its Control, Raleigh, North Carolina, to
be published December, 1976.
Hodges, J. L., R. C. Hoke, and R. R. Bertrand, "Prediction of Temperature
Profiles in Fluid Bed Boilers", ASME-AIchE Heat Transfer Conference,
St. Louis, Missouri, August 9-11, 1976.
Hoke, R. C., R. R. Bertrand, "Pressurized Fluidized-Bed Combustion of
Coal", Fluidized Combustion Conference, London, September, 1975.
Published in Institute of Fuel Symposium Series No. 1 (1975) Vol. 1.
Jonke, A. A., W. M. Swift, and G. J. Vogel, "Fluidized-Bed Combustion:
a Development Status", Trans. AIME 258, 159-167 (1975).
49
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Keairns, D. L., et al, "Fluidized-Bed Combustion Process Evaluation.
Phase TI - Pressurized Fluidized-Bed Coal Combustion Development",
EPA-690/2-75-027-C NTIS Doc. PB 246-116/AS, September, 1975.
Keairns, D. L., C. H. Peterson, and C. C. Sun, "Disposition of Spent
Calcium-Based Sorbents Used for Sulfur Removal in Fossil Fuel Gasifica-
tion", Paper Presented at the Solid Waste Management Service, 69th Annual
Meeting, AIchE, November 28-December 2, 1975.
O'Neill, E. P. and D. L. Keairns, "Selection of Calcium-Based Sorbents
for High-Temperature Fossil Fuel Desulfurization", Paper Presented at
80th AIchE, National Meeting, Boston, September 7-10, 1975.
O'Neill, E. P., D. L. Keairns, and W. F. Kittle, "A fhermogravimetric
Study of the Sulfation of Lime - The Effect of Calcination Conditions",
Thermochimica Acta 14, 209-220 (1976).
Saxena, S. and G. J. Vogel, "Properties of a Dolomite Bed of a Range of
Particle Sizes and Shapes at Minimum Fluidization", ANL/ES-CEN-1012.
Snyder, R. B., W. I. Wilson, G. J. Vogel, and A. A. Jonke, "Synthetic
Additive for S02 Removal from Off-Gas of a Fluidized-Bed Coal Combustor",
Presented at the 3rd National Conference on Energy and the Environment,
Oxford, Ohio, September 29-October 1, 1975.
Swift, W. N., G. J. Vogel, and A. F. Panek, "Potential of Fluidized-
Bed Combustion for Reducing Trace-Element Emissions", Paper Presented at
the 68th Annual Meeting of the Air Pollution Control Association,
Boston, Massachusetts, June 15-20, 1975.
Sun, C. C., and D. L. Keairns, "Environmental Impact of Solid Waste
Disposal from the Fluidized-Bed Coal Combustion Process", ACS Meeting,
August 28-September 3, 1976.
Vogel, G. J., "Reducing Pollution from Coal Combustion", Issues in
Illinois Policy - Vol. II, Proceedings of the Energy Policy and Techno-
logy Seminar, Illinois Legislative Studies Center/Sangamon State
University, July 27-30, 1975.
Vogel, G. J., P. Cunningham, J. Fischer, B. Hubble, S. Lee, J. Lenc,
J. Montagna, S. Siegel, R. Snyder, S. Saxena, W. Swift, I. Wilson, and
A. A. Jonke, "A Development Program on Pressurized Fluidized-Bed Com-
bustion", Quarterly Report, July 1, 1975-September 30, 1975,
ANL/ES-CEN-1013.
Vogel, G. J., P. Cunningham, J. Fischer, B. R. Hubble, I. Johnson,
S. H. Lee, J. F. Lenc, J. Montagna, S. Siegel, R, B. Snyder, S. Saxena,
G. Smith, W. M. Swift, G. Teats, W. I. Wilson, and A. A. Jonke, "A
Development Program on Pressurized Fluidized-Bed Combustion , Quarterly
Report, October 1, 1975-December 31, 1975, ANL/ES-CEN-1014.
Vogel, G. J., I. Johnson, P. Cunningham, B. Hubble, S. Lee, J. Lenc,
J. Montagna, S. Siegel, R. Snyder, S. Saxena, G. Smith, W. Swift,
G. Teats, I. Wilson, and A. A. Jonke, "A Development Program on
Pressurized Fluidized-Bed Combustion", Quarterly Report, January
50
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March, 1976, ANL/ES-CEN-1015 and FE-1780-4.
Vogel, G. J., W. M. Swift, J. C. Montagna, J. F. Lenc, and A. A. Jonke,
"Application of Pressurized, Fluidized-Bed Combustion to Reduction of
Atmospheric Pollution", Institute of Fuel Symposium Series No. 1:
Fluidized Combustion (1975).
Vogel, G. J., et al, "A Development Program on Pressurized Fluidized-
Bed Combustion", Annual Report July,1975-June, 1976, ANL/ES-CEN-1016
and EPA-600/7-76-019. Argonne National Laboratory, Argonne, Illinois.
51
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APPENDIX A
CURRENT PROJECTS IN THE
EPA FLUIDIZED-BED COMBUSTION PROGRAM
52
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TABLE A-l. OVERVIEW OF THE EPA FLUIDIZED-BED COMBUSTION PROGRAM
A. Broad Environmental Assessment
1. Environmental Assessment/Systems Analysis and Program Support of
Fluidized-Bed Combustion: Battelie-Columbus Laboratories
began February, 1976.
2. Preliminary Environmental Assessment of the Fluidized-Bed Combus-
tion Process: GCA Corporation, completed except for issuing
final report.
B. Comprehensive Analysis of Emissions
1. Comprehensive Analysis of Emissions from an Atmospheric-Pressure
Fluidized-Bed Combustion Unit (6 in. or 15 cm diameter): Battelle-
Columbus; with support from TRW, Inc.
2. Comprehensive Analysis of Emissions from the BCURA Pressurized
Fluidized-Bed Combustion Unit (36 in. x 24 in. or 91 x 61 cm) :
Combustion Systems, Ltd./BCURA; sampling planned for early
September, 1976.
3. Comprehensive Analysis of Emissions from the Fluidized-Bed Com-
bustion Miniplant (12.5 in. or 32 cm diameter pressurized combustor
and 8.0 in. or 20 cm diameter pressurized regenerator) and Bench-
Scale Equipment (4 in. or 10 cm pressurized batch combustor and
3.25 in. or 8 cm pressurized batch regenerator): Exxon Research
and Engineering Co., sampling planned to start 1976.
4. Comprehensive Analysis and Sampling/Analytical Technique
Development on Sampling and Analytical Test Rig (SATR) .
5, Comprehensive Analysis on Other Units: Battelle-Columbus is
preparing a plan for comprehensive analysis on other existing
and planned units.
6. Preparation of a Sampling and Analytical Manual for Fluidized-Bed
Combustion Applications: The MITRE Corporation; Revising draft of
manua1.
7. Development of Improved Sampling and Analytical Techniques: Various
Contractors.
C. Studies of Pretreatment, Modification of Process Conditions, and
Add-On Devices
1. Experimental and Engineering Support of the Fluidized-Bed Com-
bustion Program (theoretical and experimental studies using a
variety of laboratory equipment): Westinghouse Research Labora-
tories, began December, 1975, but extends previous work.
2. Support Studies of Pollutant and Waste Control in Fluidized-Bed
Combustion/Regeneration Systems (theoretical and experimental
studies using a 6 in. or 15 cm diameter pressurized combustor,
a 4,25 in. or 11 cm diameter pressurized regenerator and a
variety of laboratory equipment): Argonne National Laboratory--
co--funded with ERDA; continuing study.
53
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TABLE A-l. (Continued)
3. Miniplant and Bench-Scale Studies in Support of the Fluidized-Bed
Combustion Program (theoretical and experimental studies using the
12.5 in. or 32 cm diameter pressurized combustor and 8.0 in. or
20 cm pressurized regenerator mlnlplant plus the 4 in. or 10 cm
diameter pressurized combustor and 3.25 in. or 8 cm pressurized
regenerator bench-scale units): Exxon Research and Engineering
Company; continuing study.
4. Design, Construction and Operation of a Fluidized-Bed Coal Com-
bustion Sampling and Analytical Test Rig: Contractor to be
selected/EPA; Contract for construction to be awarded August,
1976; rig to be operable December, 1977.
5. Basic NOX studies - MIT.
D. Solid Waste Disposal
1. Environmental Assessment of Disposal of Solid Wastes from
Fluidized-Bed Combustion Units: Ralph Stone and Co.; began
December, 1975.
2. Study of Disposal of Fluidized-Bed Combustion Waste Products:
Tennessee Valley Authority; began June, 1975.
E. Application Studies
1. The Effect of Experimental Scale on Emissions from Fluidized-Bed
Combustion Units: Dow Chemical Company; Completed.
2. Application of Fluidized-Bed Technology to Industrial Boilers;
An Economic, Environmental and Energy Analysis: Exxon Research
and Engineering Company-co- funded with FEA and ERDA; Completed
except for issuing final report.
3. Cost Comparison of Commercial Atmospheric and Pressurized Fluidized-
Bed Power Plants to Conventional Coal-Fired Power Plant with Flue
Gas Desulfurization: Tennessee Valley Authority; Completed except
for issuing final report.
54
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A. Broad Environmental
Aisestment
1. Primary environmental
assessment (Sattelle)
2. Prelim, environmental
assessment (GCA)
B. Comprehensive
Analysis
t. Battelle
2, BCURA
3. Exxon
A, SATR
5. Other units
6. Sampling/analytical
manual (Mitre)
7. Sampling/analytical
technique development
C. Pretreatment. mod. of
process conditions, and
add-on devices
1. Engineering and
lab-scale (West-
inghouse)
2. Lab and bench-
scale (Argonnel
3. Bench-scale and
Mimplani (Exxon)
4. Sampling/analytical
Test rig
5. Basic studies-NO,,
(MIT)
D. Solid Waste Disposal
1. Primary disposal/
utilization effort
(Ralph Stone)
2. Solid waste
characterization (TVA)
3, Solid waste charac-
terization and dis-
posal (Westinghouse)
E. Application Studies
1. Effect of scale
(Dow)
2. Industrial FBC
application (Exxon)
3. FBC/FGD cost
comparison (TVA)
9/1
6/30
7/15
6/30
6/30
2/i
SeeC-3
•
below
6/30
Renod Covered by Report
6/1
.
<3/i H"
12/1
fi/15
* SeeC-4 beiow^^
,975 1976 1977 1978
12/15
12/15
FIGURE A-1. THE EPA FLUIDIZED BED COMBUSTION PROGRAM
• Project start*
4 Project finishes
• Project continues
55
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TECHNICAL REPORT DATA
(Please read Inunctions on the reverse before completing)
1. REPORT NO.
EPA-600/7-77-012
3. RECIPIENT'S ACCESSION* NO.
4. TITLE AND SUBTITLE
The U.S. Environmental Protection Agency's
Fluidized-Bed Combustion Program, FY 1976
5. REPORT DATE
February 1977
6. PERFORMING ORGANIZATION CODE
7. AUTHOH(S)
8. PERFORMING ORGANIZATION REPORT NO
(Individuals not identified)
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Batte lie-Columbus Laboratories
505 King Avenue
Columbus, Ohio 43201
10. PROGRAM ELEMENT NO.
E HE 62 3 A
11. CONTRACT/GRANT NO.
68-02-2138
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Annual Status; 7/75-9/76
14. SPONSORING AGENCY CODE
EPA/600 A3
™««« NOTES There was no previous annual program status report published,
IERL-RTP project officer for this report was D. B. Henschel, Mail TJropr 61, JJ19/549-
8411 Ext 2851.
16. ABSTRACT
The report describes the objectives, content, and fiscal year 1976 progress
of the research and development program being conducted by the EPA for environ-
mental characterization of the fluidized-bed combustion (FBC) process. EPA's FBC
program is a contract program, utilizing a variety of contractors, aimed at ensuring
that all potential environmental problems associated with this developing energy tech-
nology are identified and adequately addressed. EPA's program is being conducted
in coordination with the FBC technology development program being conducted by the
U.S. Energy Research and Development Administration (ERDA). Some important
contributions of EPA's FBC program to the National effort will include: establishment
of environmental goals based on health and ecological effects of emitted pollutants;
comprehensive analyses of emissions from operating FBC units; assessment and
development of any necessary environmental control technology; recommendations
for environmental standards for the process; and development of manuals of best
available technology.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
COSATl Field/Croup
Air Pollution
Fluidized-Bed
Processors
Desulfurization
Flue Gases
Limestone
Dolomite (Rock)
Calcium Oxides
Nitrogen Oxides
Waste Disposal
Combustion
Residues
Air Pollution Control
Stationary Sources
Fluid-Bed Combustion
Environmental Assess-
ment
Sorbent Regeneration
Hnntrnl
13B
07A
07D
21B
08G
07B
13. DISTRIBUTION STATEMENT
Unlimited
EPA Form 2220-1 (9-73)
Unclassified
63
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
56
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