EPA 600/R-14/261 I September 2014 I www.epa.gov/research
United States
Environmental Protection
Agency
Adsorption and Desorption of
Chemical Warfare Agents on
Activated Carbon: Impact of
Temperature and Relative Humidity
Office of Research and Development
National Homeland Security Research Center
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Adsorption and Desorption of Chemical Warfare
Agents on Activated Carbon:
Impact of Temperature and Relative Humidity
National Homeland Security Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
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DISCLAIMER
The United States Environmental Protection Agency (EPA), through its Office of Research and
Development (ORD) funded and managed the research described here through EPA Contract
Number EP-C-10-001 with Battelle. This report has been subjected to the Agency's review and
has been approved for publication as an Environmental Protection Agency report. Note that
approval does not signify that the contents necessarily reflect the views of the Agency. Mention
of trade names, products, or services does not convey official EPA approval, endorsement, or
recommendation.
Questions concerning this document or its application should be addressed to:
Lukas Oudejans, Ph.D.
Decontamination and Consequence Management Division
National Homeland Security Research Center
Office of Research and Development
U.S. Environmental Protection Agency (MD-E343-06)
109 T.W. Alexander Dr.
Research Triangle Park, NC 27709
Phone: 919-541-2973
Fax: 919-541-0496
E-mail: Oudejans.Lukas@epa.gov
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ACKNOWLEDGMENTS
The following individuals are acknowledged for review of this document:
United States Environmental Protection Agency:
Office of Solid Waste and Emergency Response, Office of Emergency Management
Shannon Serre (on detail from Office of Research and Development, National
Homeland Security Research Center)
Office of Solid Waste and Emergency Response, Office of Superfund Remediation &
Technology Innovation
Dave Mickunas
Office of Research and Development, National Homeland Security Research Center
Paul Lemieux
Ramona Sherman (QA review)
Contributions of the following organizations to the development of this document are
gratefully acknowledged.
Battelle Memorial Institute
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TABLE OF CONTENTS
DISCLAIMER i
ACKNOWLEDGMENTS ii
TABLE OF CONTENTS iii
LIST OF FIGURES v
LIST OF TABLES ix
ABBREVIATIONS AND ACRONYMS x
EXECUTIVE SUMMARY xii
1.0 INTRODUCTION 1
1.1 Project Objective 2
1.2 Test Facility Description 2
2.0 TECHNICAL APPROACH 3
2.1 Activated Carbon Products 3
2.2 Testing Apparatus 4
2.2.1 Air Flow Handling 5
2.2.2 Temperature and Relative Humidity 5
2.2.3 Carbon Bed 6
2.2.4 CWA Vapor Generation 7
2.3 Analytical Methods 11
2.4 Test Procedures 12
2.4.1 Carbon Bed Pre-conditioning 12
2.4.2 Adsorption and Desorption Testing 13
2.5 Test Matrix 15
3.0 QUALITY ASSURANCE AND QUALITY CONTROL 17
3.1 Data Quality Objectives and Results 17
3.2 Equipment Calibrations 21
3.3 Technical System Audit 21
3.4 Data Quality Audit 21
4.0 TEST RESULTS 23
4.1 Equilibrium Time 23
4.2 Preliminary Testing with GB Surrogate 23
4.3 Results for GB 23
4.3.1 ASZM-TEDA (6 x 16 Mesh) Carbon Tests 24
m
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4.3.2 IONEX 03-001 (8 x 16 Mesh) Carbon Tests 26
4.3.3 Vapure 612 Carbon Tests 30
4.3.4 ASZM-TEDA (12 x 30 Mesh) Carbon Tests 34
4.3.5. High Humidity Adsorption and Desorption Studies 38
4.4 Results for HD 39
4.4.1 IONEX 03-001 (8 x 16 Mesh) Carbon Tests with HD 39
4.4.2 ASZM-TEDA (12 x 30 Mesh) Carbon Tests with HD 45
4.4.3 ASZM-TEDA (6 x 16 Mesh) Carbon Test with HD 49
5.0 SUMMARY 51
5.1 Sarin, GB 51
5.2 Sulfur Mustard, HD 53
6.0 GENERAL CONCLUSIONS 56
7.0 REFERENCES 58
APPENDIX A: CARBON BED EQUILIBRIUM TESTS A-l
A.I INTRODUCTION A-2
A.2 TEST METHOD A-2
A.3 TEST RESULTS A-4
A.3.1 Carbon Bed Equilibrium Time at 55 ± 2 °C and 50 ± 5 % RH A-4
A.3.2 Carbon Bed Equilibrium Time at Dry Conditions (RH< 15%) A-8
APPENDIX B: OPERATIONAL PARAMETERS FOR THE MINICAMS® B-1
APPENDIX C: PLOTS OF GB and HD CHALLENGE CONCENTRATIONS,
TEMPERATURE, RH, FLOW RATE, AND AP C-l
IV
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LIST OF FIGURES
Figure 1. Schematic of the test system used for carbon performance evaluation 4
Figure 2. Photograph of the carbon bed holder 7
Figure 3. Schematic of vapor generation system 9
Figure 4. Schematic of the liquid infusion vapor generation system 10
Figure 5. Photographs of the syringe pump vapor infusion apparatus: (lower)
programmable syringe pump with loaded syringe, connected to a transfer line,
leading to (upper) valve 8 connection to heated transfer line 11
Figure 6. Loading the carbon test cell with IONEX 03-001 carbon (8 x 16 mesh): (A)
mesh screen in bottom cell piece and O-ring in the well at the top of the cell, (B)
pre-weighed carbon loaded into bottom cell piece, (C) cell bottom with level and
packed loaded carbon, (D) mesh screen on top of carbon bed, and (E) top cell piece
screwed on using locking ring 13
Figure 7. Typical test chamber configuration for carbon bed adsorption and desorption
testing 14
Figure 8. Breakthrough and desorption curves at 25 °C/dry and varying bed depth for
ASZM-TEDA (6^16 mesh) carbon. Desorption phase starts at the transition from
solid to open symbols 26
Figure 9. Breakthrough and desorption curves of the IONEX 03-001 carbon at 25 °C/dry.
Desorption phase starts at the transition from solid to open symbols 27
Figure 10. Breakthrough and desorption curves of the IONEX 03-001 carbon at 55 °C/dry.
Desorption phase starts at the transition from solid to open symbols 29
Figure 11. A comparison of the IONEX 03-001 carbon performance at 25 °C/dry and 55
°C/dry. Desorption phase starts at the transition from solid to open symbols 30
Figure 12. Breakthrough and desorption curves of the Vapure 612 carbon at 25 °C/dry.
Desorption phase starts at the transition from solid to open symbols 32
Figure 13. Breakthrough and desorption curves of the Vapure 612 carbon at 55 °C/dry.
Desorption phase starts at the transition from solid to open symbols 33
Figure 14. A comparison of the Vapure 612 carbon performance at 25 °C/dry and
55 °C/dry. Desorption phase starts at the transition from solid to open symbols 34
Figure 15. Summary graph of ASZM-TEDA (12 x 30 mesh) carbon challenged with GB
vapor at 25 °C /dry conditions. Desorption phase starts at the transition from solid
to open symbols 36
Figure 16. Summary graph of ASZM-TEDA (12 x 30 mesh) carbon challenged with GB
vapor at 55 °C/dry conditions. Desorption phase starts at the transition from solid to
open symbols 37
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Figure 17. Summary graph of ASZM-TEDA (12 x 30 mesh) carbon challenged with GB
vapor at 55 °C/dry conditions. Desorption phase starts at the transition from solid to
open symbols 38
Figure 18. Summary graph of IONEX 03-001 carbon challenged with FID vapor at 25
°C/dry conditions. Desorption phase starts at the transition from solid to open
symbols 40
Figure 19. Summary graph of IONEX 03-001 carbon challenged with HD vapor at 55
°C/dry conditions. Desorption phase starts at the transition from solid to open
symbols 41
Figure 20. Summary of HD adsorption and desorption for IONEX 03-001 carbon at 25
°C/dry and 55 °C/dry conditions. Desorption phase starts at the transition from
solid to open symbols 42
Figure 21. Summary graph of IONEX 03-001 carbon challenged with HD vapor at 55
°C/humid conditions 44
Figure 22. Summary graph of ASZM-TED A (12 x 30 mesh) carbon challenged with HD
vapor at 25 °C/dry conditions. Desorption phase starts at the transition from solid to
open symbols 46
Figure 23. Photographs of ASZM-TED A (12 x 30 mesh) carbon before (left) and after
(right) exposure to HD vapor at 25 °C/dry conditions 46
Figure 24. Summary graph of ASZM-TED A (12 x 30 mesh) carbon challenged with HD
vapor at 55 °C/dry conditions. Desorption phase starts at the transition from solid to
open symbols 47
Figure 25. Summary graph of ASZM-TED A (12 x 30 mesh) carbon challenged with HD
vapor at 55 °C/humid conditions. Desorption phase starts at the transition from
solid to open symbols 48
Figure 26. Summary graph of ASZM-TED A (6x16 mesh) carbon challenged with HD
vapor at 25 °C/dry conditions. Desorption phase starts at the transition from solid to
open symbols 50
Figure A-1. Schematic of the test system used for carbon performance evaluation A-3
Figure A-2. ASZM-TEDA (6x16 mesh) carbon bed weight gain versus preconditioning
time at 55 ± 2 °C and 50 ± 5% RH A-5
Figure A-3. IONEX 03-001 (8x16 mesh) carbon bed weight gain versus preconditioning
time at 55 ± 2 °C and 50 ± 5% RH A-6
Figure A-4. Vapure 612 (6 x 12 mesh) carbon bed weight gain versus preconditioning
time at 55 ± 2 °C and 50 ± 5% RH A-7
Figure A-5. ASZM-TEDA (6x16 mesh) carbon bed weight change versus
preconditioning time at 55 ± 2 °C and dry A-9
Figure A-6. ASZM-TEDA (6x16 mesh) carbon bed weight change versus
preconditioning time at 25 ± 2 °C and dry A-10
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Figure A-7. IONEX 03-001 (8 x 16 mesh) carbon bed weight change versus
preconditioning time at 55 ± 2 °C and dry A-11
Figure A-8. IONEX 03-001 (8x16 mesh) carbon bed weight change versus
preconditioning time at 25 ± 2 °C and dry A-12
Figure A-9. Vapure 612 (6 x 12 mesh) carbon bed weight change versus preconditioning
time at 55 ± 2 °C and dry A-13
Figure A-10. Vapure 612 (6 x 12 mesh) carbon bed weight change versus preconditioning
time at 25 ± 2 °C and dry A-14
Figure B-1. Operational parameters of the MINIC AMS® for GB detection B-2
Figure B-2. Operational parameters of the MINIC AMS® for HD detection B-3
Figure C-l. ASZM-TEDA (6x16 mesh) carbon, 2.5 cm bed depth, 25 °C/dry C-2
Figure C-2. ASZM-TEDA (6x16 mesh) carbon, 3.0 cm bed depth, 25 °C/dry C-3
Figure C-3. ASZM-TEDA (6x16 mesh) carbon, 3.5 cm bed depth, 25 °C/dry, Run 1 C-4
Figure C-4. ASZM-TEDA (6 x 16 mesh) carbon, 3.5 cm bed depth, 25 °C/dry, Run 2 C-5
Figure C-5. IONEX 03-001 carbon, 3.5 cm bed depth, 25 °C/dry, Run 1 C-6
Figure C-6. IONEX 03-001 carbon, 3.5 cm bed depth, 25 °C/dry, Run 2 C-7
Figure C-l. IONEX 03-001 carbon, 3.5 cm bed depth, 55 °C/dry, Run 1 C-8
Figure C-8. IONEX 03-001 carbon, 3.5 cm bed depth, 55 °C/dry, Run 1 (Continued) C-9
Figure C-9. IONEX 03-001 carbon, 3.5 cm bed depth, 55 °C/dry, Run 2 C-10
Figure C-10. IONEX 03-001 carbon, 3.5 cm bed depth, 55 °C/dry, Run 2 (continued) C-ll
Figure C-l 1. Vapure 612 carbon, 3.5 cm bed depth, 25 °C/dry Run 1 C-12
Figure C-12. Vapure 612 carbon - 25 °C/dry, 3.5 cm bed depth, Run 2 C-13
Figure C-13. Vapure 612 carbon - 55 °C/dry, 3.5 cm bed depth, Run 1 C-14
Figure C-14. Vapure 612 carbon - 55 °C/dry, 3.5 cm bed depth, Run 1 (continued) C-15
Figure C-15. Vapure 612 carbon - 55 °C/dry, 3.5 cm bed depth, Run 2 C-16
Figure C-16. Vapure 612 carbon - 55 °C/dry, 3.5 cm bed depth, Run 2 (continued) C-17
Figure C-17. Temperature and RH measurement for GB adsorption/desorption on ASZM-
TEDA (12 x 30 mesh) carbon at 25 °C/dry conditions C-18
Figure C-18. Pressure differential measurement (upper bed) for GB adsorption /
desorption on ASZM-TEDA (12 x 30 mesh) carbon at 25 7dry conditions C-18
Figure C-l9. Temperature and RH measurement for GB adsorption/desorption on ASZM-
TEDA (12 x 30 mesh) carbon at 55 °C/dry conditions C-19
Figure C-20. Pressure differential measurement (upper bed) for GB adsorption/desorption
on ASZM-TEDA (12 x 30 mesh) carbon at 55 °C/dry conditions C-19
VII
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Figure C-21. Temperature and RH measurement for HD adsorption/desorption on IONEX
03-001 carbon at 25 °C/dry conditions C-20
Figure C-22. Pressure differential measurement (upper bed) for FID adsorption/desorption
on IONEX 03-001 carbon at 25 °C/dry conditions C-20
Figure C-23. Temperature and RH measurement for HD adsorption/desorption on IONEX
03-001 carbon at 55 °C/dry conditions C-21
Figure C-24. Pressure differential measurement (upper bed) for HD adsorption/desorption
on IONEX 03-001 carbon at 55 °C/dry conditions C-21
Figure C-25. Temperature and RH measurement for HD adsorption/desorption on IONEX
03-001 carbon at 55 °C/humid conditions C-22
Figure C-26. Pressure differential measurement (upper and lower bed) for HD
adsorption/desorption on IONEX 03-001 carbon at 55 °C/humid conditions C-22
Figure C-21. MINICAMS® sampling flow rate capture data for IONEX 03-001 carbon at
55 °C/humid conditions C-23
Figure C-28. Temperature and RH measurement for HD adsorption/desorption on ASZM-
TEDA (12 x 30 mesh) carbon at 25 °C/dry conditions C-24
Figure C-29. Pressure differential measurement (upper bed) for HD adsorption/desorption
on ASZM-TEDA (12 x 30 mesh) carbon at 25 °C/dry conditions C-24
Figure C-30. Temperature and RH measurement for HD adsorption/desorption on ASZM-
TEDA (12 x 30 mesh) carbon at 55 °C/dry conditions C-25
Figure C-31. Pressure differential measurement (upper bed) for HD adsorption/desorption
on ASZM-TEDA (12 x 30 mesh) carbon at 55 °C/dry conditions C-25
Figure C-32. Temperature and RH measurement for HD adsorption/desorption on ASZM-
TEDA (12 x 30 mesh) carbon at 55 °C/humid conditions C-26
Figure C-33. Pressure differential measurement (upper bed) for HD adsorption/desorption
on ASZM-TEDA (12 x 30 mesh) carbon at 55 °C/humid conditions C-26
Figure C-34. MINICAMS® sampling flow rate capture data for ASZM-TEDA (12 x 30
mesh) carbon at 55 °C/humid conditions C-27
Figure C-3 5. Temperature and RH measurement for HD adsorption/adsorption on ASZM-
TEDA (6 x 16 mesh) carbon at 25 °C/dry conditions C-28
Figure C-36. Pressure differential measurement (upper bed) for HD adsorption/desorption
on ASZM-TEDA (6 x 16 mesh) carbon at 25 °C/dry conditions C-28
vm
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LIST OF TABLES
Table ES-1. Summary of tested conditions. Numbers refer to number of tests at identified condition.... xiii
Table ES-2. Summary of trends in breakthrough times with respect to 25 °C/dry adsorption results xvii
Table 1. Relevant properties of selected carbons 3
Table 2. Complete test matrix 16
Table 3. Critical data quality objectives and results 19
Table 4. Dynamic desorption capacities for GB of tested carbons based on 3.5 cm bed depth
measurements 52
Table 5. Dynamic desorption capacities for HD of tested carbons based on 2.5 cm bed depth
measurements under dry (< 15% RH) conditions 54
Table 6. Summary of trends in breakthrough times with respect to 25 °C adsorption results 57
IX
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ABBREVIATIONS AND ACRONYMS
ASTM American Society for Testing and Materials, now ASTM International
ASZM copper, silver, zinc, molybdenum
BPL bituminous pulverized low (ash)
°C degree(s) Celsius
cm centimeter(s)
CCV continuing calibration verification
CWA chemical warfare agent
DMMP dimethyl methylphosphonate
EPA U.S. Environmental Protection Agency
FID flame ionization detector
FPD flame photometric detector
ft2 square foot
g gram(s)
GB isopropyl methylphosphonofluoridate, nerve agent (sarin)
GC gas chromatograph
HD bis(2-chloroethyl)sulfide, blister agent (sulfur mustard)
HEPA high-efficiency particulate air
HF hydrofluoric acid
HMRC Hazardous Materials Research Center
h hour(s)
HVAC heating, ventilation, and air conditioning
ID inner diameter
IDLH immediately dangerous to life or health
in inch(es)
L liter(s)
Lpm liter(s) per minute
m meter(s)
m2 square meter(s)
m3 cubic meter(s)
MFC mass flow controller
MFM mass flow meter
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mg
min
mL
mm
NHSRC
NIST
OD
ppm
QA
QC
2
r
RH
RPD
s
SOP
SOW
SST
STEL
T
TDG
TEDA
TGD
TIC
TSA
VX
microliter(s)
milligram(s)
minute(s)
milliliter(s)
millimeter(s)
National Homeland Security Research Center
National Institute of Standards and Technology
outer diameter
part(s) per million
quality assurance
quality control
coefficient of determination
relative humidity
relative percentage of difference
second(s)
standard operating procedure
statement of work
solid sorbent tube
short term exposure limit
temperature
thiodiglycol
triethylenediamine
thickened soman
toxic industrial chemical
technical systems audit
ethyl({2-[bis(propan-2-yl)amino]ethyl}sulfanyl)(methyl)phosphinate,
nerve agent
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EXECUTIVE SUMMARY
This project supports the mission of the U.S. Environmental Protection Agency's (EPA)
Office of Research and Development's (ORD) Homeland Security Research Program (HSRP) to
conduct research and develop scientific products that improve the capability of EPA to carry out
its homeland security responsibilities. The known threat of a chemical agent release in a building
or transportation hub is necessitating the EPA's National Homeland Security Research Center
(NHSRC) to develop of a research program to evaluate potential decontamination strategies. The
EPA may be tasked to clean up or provide technical support related to these agents after a release
in buildings. Knowledge of how effective many of the available fumigation technologies are
against chemical agents is currently being developed by NHSRC for various fumigation methods
such as (modified) hydrogen peroxide vapor, chlorine dioxide vapor, and hot (humid) air.
Hot air has been assessed for the gaseous decontamination of sarin (GB), VX, sulfur
mustard (HD), and thickened soman (TGD) from indoor building materials as a less complicated
alternative to (modified) hydrogen peroxide vapor or chlorine dioxide vapor. Enhanced
volatilization of chemical warfare agents (CWAs) by increasing the temperature through
introduction of hot (humid) air into a building using the existing building heating, ventilation and
air conditioning (HVAC) system is a valuable and relatively low cost decontamination option for
an indoor facility. Such approach would require a uniform heat distribution of such facility as to
avoid cold spots that could act as sinks for volatilized agent vapor. Negative air machines/air
scrubbers outfitted with carbon filters and air heating elements could also be considered to
remove chemical agents from indoor environments. Either way, collective protection (filtration)
systems would be required to either prevent transfer of the CWA vapor to the outside
environment or to adsorb the agent during recirculation of (building) air. The heated air that is
generated would cause an increase in carbon temperature that is likely to impact the carbon
adsorption characteristics, resulting in a potentially poorer carbon adsorption performance with
shorter breakthrough times. This impact on the carbon adsorption characteristics would lead to
an unintended earlier release of hazardous agent in the effluent of the carbon bed.
The objective of this study was to determine the dynamic adsorption and desorption
performance of activated carbon beds through measurement of the initial breakthrough and
desorption curves at ambient and elevated temperatures. Results from this evaluation can be
Xll
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used by responders to assess the capability of carbon filters in HVAC applications to capture the
CWA under ambient and elevated temperature conditions. The measurement of desorption of
the CWA from the activated carbon would indicate whether off-gassing from activated carbon
air filters is a potential concern when these filters are removed from service as part of the waste
management.
Four types of activated carbons, Calgon Carbon ASZM-TEDA (6 x 16 mesh and 12 x 30
mesh), IONEX Research IONEX 03-001 (8 x 16 mesh), and Cabot Norit® Vapure™ 612 (6 x 12
mesh) were tested against two chemical warfare agents, namely, sarin (O-Isopropyl
methylphosphonofluoridate, GB) and sulfur mustard (bis(2-chloroethyl) sulfide, HD). Each of
these carbons is used frequently in either HVAC carbon filters or respirator cartridges. Vapor
challenges for adsorption and desorption performance were performed for the activated carbon
types with various mesh sizes, as summarized in Table ES-1. All carbons were in equilibrium
with the environmental conditions prior to the start of the agent challenge.
Table ES-1. Summary of tested conditions. Numbers refer to number of tests at identified
condition.
Carbon Type Mesh Size Agent Temperature (°C) / RH , ,p
Calgon Carbon ASZM-TEDA™
IONEX Research IONEX 03-001
Norit® Vapure™ 612
Calgon Carbon ASZM-TEDA™
IONEX Research IONEX 03-001
Calgon Carbon ASZM-TEDA™
6 x 16
8 x 16
6 x 12
12 x 30
8 x 16
12 x 30
GB
GB
GB
GB
HD
HD
25/drya
1
1
2
2
2
1
1
1
Calgon Carbon ASZM-TEDA™ 6x16 HD 1
55/dry
2
2
1
1
1
55/humid
lb
1C[50%RH]
1 [20 % RH]
2.5
3.0
3.5
3.5
3.5
2.5
2.5
2.5
2.5
a dry: < 10 % relative humidity (RH)
b attempted; detection of hydrofluoric acid (HF) in effluent prevented test
0 incomplete test due to condensation in sample line
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The target test challenge concentration was 1,500 milligrams/cubic meter (mg/m3) of GB
and 500 mg/m3 HD. Both concentrations were derived from a release of 1 liter (L) of liquid agent
into a 168 square meter (m2) (2000 square foot [ft2]) office-type area (no air exchange assumed)
with the HD concentration limited by its saturation concentration.
Three environmental conditions were considered, namely, dry RH less than 10 %)
conditions at 25 °C as a reference condition and 55 °C temperature (T) while a more humid (50
% RH targeted) condition was included at 55 °C. The 55 °C temperature is considered to be close
to the upper boundary temperature that can be used during hot air fumigation without damage
(e.g., to electrical wiring inside a building).
Summary of Results for GB
Among the four types of activated carbons tested, the ASZM-TEDA (12 x 30 mesh) and
IONEX 03-001 carbons demonstrated the best GB adsorption performance, with the IONEX 03-
001 carbon bed effluent concentration held at <0.04 mg/m3 for 85 and 170 minutes (min) at 25
°C/dry and 55 °C/dry conditions, respectively. Comparable adsorption curves were obtained for
the GB vapor on the ASZM-TEDA (12 x 30 mesh) carbon bed as the effluent concentration was
held at < 0.04 mg/m3 for 140 min at 25 °C/dry conditions. Note that the ASZM-TEDA (12 x 30
mesh) carbon results are based on a 2.5 centimeters (cm) bed depth while the other coarser
carbons were tested with a 3.5 cm bed depth. This shallower bed depth selection was based on
observations (i.e., lack of measurable breakthrough) for HD for a 2.5 cm bed depth. Immediate
breakthrough occurred with both the ASZM-TEDA (6x16 mesh) and Vapure™ 612 carbon
beds, as the GB concentration in the effluent steadily increased initially, albeit very gradually.
Contrary to anticipated results, increasing the temperature from 25 °C/dry to 55 °C/dry
did not appear to affect carbon bed adsorption performance adversely for the coarser (low mesh
size) carbons. Significantly better adsorption performance was measured for the IONEX 03-001
carbon bed and better adsorption performance was observed for the Vapure™ 612 carbon in the
initial stages of the adsorption phase. There is no definitive explanation for this observation.
Prolonged (>16 hours [h]) preconditioning at 55 °C/dry was believed to be a factor, because the
carbon might desorb contaminants or water vapor out of the carbon pores to increase the
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adsorption capacity. A weight loss of 4 and 5 %, respectively, was associated with
preconditioning the IONEX 03-001 and Vapure™ 612 carbon at 55 °C/dry conditions. Increasing
temperature from 25 °C/dry to 55 °C/dry shifted the onset of GB adsorption to shorter times for
the finer ASZM-TEDA (12 x 30 mesh), in line with expectations.
GB desorption from the carbon bed was observed for all four types of carbons after the
GB challenge was stopped and clean air was pulled through the carbon bed at the flow and T/RH
conditions equivalent to the adsorption test. In general, the GB concentration downstream of the
carbon bed, as a result of GB desorbing from the carbon, decreased quickly in the initial stages
of desorption and then leveled off. The desorption behavior was dependent on temperature.
After an initial drop in GB concentration downstream of the carbon (effluent stream), the GB
concentration continued to decrease with time as 25 °C, dry clean air continued to flow through
the carbon bed. Conversely, after an initial decrease in GB concentration, the GB concentration
in the effluent gradually increased with time as 55 °C, dry clean air continued to flow through the
carbon bed. Consequently, GB desorption may pose more risk at the higher temperature of 55
°C, because of the slowly increasing trend of the desorption concentration with time.
Adsorption studies at higher RH were originally planned. However, HF was detected in
the effluent of a preliminary test at 55 °C/50 % RH using a shallow IONEX 03-001 carbon bed.
Consequently, tests originally planned at the higher RH conditions were not executed to prevent
catastrophic failure of the sensitive analytical equipment that measured the effluent GB vapor.
Hydrolysis of GB results in the formation of HF as a decomposition product and is expected to
be enhanced/faster at high temperature and RH. Since HF is highly corrosive, tests should be
conducted to quantify the formation of HF under different T/RH conditions. The results would
indicate whether HF formation is a potential risk to, e.g., the metal ductwork in HVAC
applications. Using the aforementioned release scenario and assuming complete hydrolysis of
GB with no air exchange, the HF concentration could be as high as 260 parts per million (ppm).
This concentration is at the lower end of laboratory studies that investigate the impact of HF on
(electronic) equipment. A further assessment of the impact that HF may have on metal ductwork
was beyond the scope of this study.
Desorption from the carbon beds was persistent for all types of carbons tested, with
desorption concentrations sustained at levels of three to four order of magnitude higher than the
short term exposure limit (STEL) (i.e., 0.0001 mg/m3 for GB) after 10 hours of desorption. Only
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a small quantity of the adsorbed GB, however, was desorbed. After desorption for up to ten
hours, less than 1 % of the adsorbed GB had been desorbed at both 25 °C/dry and 55 °C/dry
conditions for all three types of carbons tested.
Summary of Results for HD
In HD vapor challenge tests, the ASZM-TEDA (12 x 30 mesh) carbon out-performed the
IONEX 03-001 carbon and the ASZM-TEDA (6x16 mesh) carbon. No evidence of
breakthrough was observed after nearly six hours of HD vapor exposure under all three sets of
test conditions using the ASZM-TEDA (12x30 mesh) carbon. The IONEX 03-001 carbon
began exhibiting breakthrough behavior at approximately three to four hours. Comparison of the
ASZM-TEDA (12x30 mesh) results to the ASZM-TEDA (6x16 mesh) results under the 25
°C/dry conditions indicated that the difference in particle size in the carbon bed was the primary
reason for this difference in breakthrough behavior.
Similar to the observation made in GB testing, increasing the test temperature from 25 °C
to 55 °C did not appear to impact the HD vapor adsorption behavior of the IONEX 03-001
carbon significantly. Desorption of HD, however, was more rapid at 55 °C compared to the 25
°C test conditions.
Testing HD vapor adsorption and desorption at 55 °C/humid conditions was complicated
by the formation of condensation in the post-MINICAMS® sample flow system. Thiodiglycol
(TDG), the primary HD hydrolysis product, was detected in effluent samples at the conclusion of
the challenge period and in an extracted sample of the ASZM-TEDA (12 x 30 mesh) test carbon
exposed to HD. Neither the IONEX 03-001 nor the ASZM-TEDA (12 x 30 mesh) carbon
achieved HD vapor breakthrough during the test under the 55 °C/humid conditions.
Table ES-2 summarizes the changes in breakthrough times when comparing them to the
reference breakthrough time(s) observed at 25 °C/dry test condition.
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Table ES-2. Summary of trends in breakthrough times with respect to 25 °C/dry
adsorption results.
Carbon Type
Calgon Carbon
ASZM-TEDA™
Calgon Carbon
ASZM-TEDA™
IONEX Research
IONEX 03-001
Norit®Vapure™612
Mesh Size
6 x 16
12 x 30
8 x 16
6 x 12
55 °C/dry
ND
—
++
—
55 °C/humid
NAa
NAa
NDa
NAa
55 °C/dry
NA
+/-
==
NA
55 °C/humid
NA
+/-
++b
NA
++: longer breakthrough time
==: equal breakthrough time; no discernable impact
—: shorter breakthrough times
+/-: no breakthrough observed for any condition
ND: Not Determined
NA: Not Attempted
aNot determined due to observed formation of HF in effluent
b Enhanced HD hydrolysis extends breakthrough time
Results from this study are limited to one targeted concentration per CWA. Different
concentrations will result in different breakthrough times. However, the impact of temperature
and RH, the main objective of this study, would be as shown in this report. It is evident from the
results that most carbons tested at the 3.5 cm bed depth are unable to keep the effluent at or
below recommended safe vapor concentration levels. As such, a deeper bed or multiple
shallower beds in series are recommended.
Breakthrough time comparisons made in this report assume that the impact of
temperature, bed thickness and RH are independent. Any dependence among these parameters, if
present, could not have been estimated in this study because of the lack of replicates for most of
the experimental test conditions. The inherent difficulty of using CWAs in large quantities
(milliliters (mL) of agent consumed per test) limits a more thorough research effort including
sufficient replicates to identify the actual accuracy of each breakthrough test.
XVll
-------
Impact of Study
This research provides information on the impact of temperature and RH on the performance
of activated carbon beds as to capture chemical warfare agent vapors. The observed changes in
breakthrough times for GB and HD at elevated temperatures and RH will provide decision makers
with information for the use of these activated carbon to capture the effluent at elevated
temperatures. This will facilitate their use as part of a hot air decontamination technology.
XVlll
-------
1.0 INTRODUCTION
The primary mission of the U.S. Environmental Protection Agency's (EPA's) Office of
Research and Development's (ORD's) Homeland Security Research Program (HSRP) is to
conduct research and develop scientific products that improve the capability of EPA to carry out
its homeland security responsibilities. The known threat of a chemical agent release in a building
or transportation hub is necessitating the U.S. EPA's National Homeland Security Research
Center (NHSRC) to develop of a research program that evaluates potential decontamination
strategies. The EPA may be tasked to clean up these agents after a release in buildings.
Knowledge of how effective many of the available fumigation technologies are against chemical
warfare agents (CWAs) is currently being obtained by NHSRC for various fumigation methods
such as (modified) hydrogen peroxide vapor [Wagner et al., 2007, EPA 2010], chlorine dioxide
vapor [EPA 2009, EPA 2011], and hot (humid) air. Hot air has been assessed for the gaseous
decontamination of sarin (GB), VX, sulfur mustard (HD), and thickened soman (TGD) as a less
complicated alternative to, for example, (modified) hydrogen peroxide vapor or chlorine dioxide
vapor. The effluent during hot air fumigation is likely to contain CWA (and/or by-product)
vapors well above the airborne exposure limit. These vapors therefore need to be captured before
release of the CWA-loaded hot air to the exterior. Such capture is expected to occur from air
flows at elevated temperatures and humidity because of the nature of the decontamination
system. The elevated temperatures and relative humidity may affect the ability of carbon in the
air filtration system to capture the CWA (or CWA decontamination by-products or
decomposition products). The measurement of desorption of the CWA from the activated carbon
would indicate whether off-gassing from activated carbon air filters is a potential concern when
these filters are removed from service.
There are limitations on the highest temperatures that could be used during hot air
decontamination. Aside from the technical difficulties associated with reaching high
temperatures inside a building due to energy losses to the outside, high temperatures above
approximately 60 °C are known to be detrimental to electrical wiring insulation. Hot air
decontamination is therefore considered to be limited to this maximum temperature if used in an
occupied building that is expected to be reused without retrofitting the electrical wiring.
-------
1.1 Project Objective
The objective of this project was to determine the impact of temperature and relative
humidity (RH) on the dynamic adsorption and desorption performance of activated carbon beds
by measurement of the breakthrough and desorption curves of the activated carbon beds at
ambient and elevated temperatures to assess the capability of carbon filters in heating,
ventilation, and air conditioning (HVAC) applications to capture the CWAs under ambient and
elevated temperature conditions. Adsorption characteristics of carbons against chemicals are in
most cases measured at room temperature. Less information is available on the impact of
temperature and RH, especially for the targeted CWAs.
1.2 Test Facility Description
All testing was performed at the Battelle's Hazardous Materials Research Center
(HMRC) located on the Battelle site in West Jefferson, Ohio. Battelle is certified to work with
chemical surety materials through its contract with the Defense Threat Reduction Agency
(contract number: W81XWH-1 l-D-0002).
-------
2.0 TECHNICAL APPROACH
2.1 Activated Carbon Products
Four different carbon types/sizes were selected for testing. Properties of these activated
carbons are summarized in Table 1. The coarser (lower mesh size numbers) carbons are
frequently used in HVAC units or in negative air machines if outfitted with carbon "vapor"
filters. The finer (higher mesh size numbers) carbons can be found in e.g., responder masks
designed to protect against various toxic industrial chemicals (TICs) and CWAs. In principle,
finer carbons provide better protection against TICs or CWAs due to their greater adsorption
capacity. However, the flow resistance (measured as the pressure drop across such carbon)
would also be higher. Therefore, the finer carbons are not always desirable for standard use in
common building HVAC systems due to the higher energy consumption to run such systems.
Nevertheless, the finer ASZM-TEDA (12 x 30 mesh) carbon is known to be used in HVAC
systems of buildings of high economic, political or historic relevance.
Table 1. Relevant properties of selected carbons.
Carbon Manufacturer , Location Type Mesh Size Impregnated Bulk Density
(g/mL)
ASZM-TEDA
IONEX 03-001
Vapure™ 612
Calgon Carbon
Pittsburgh, PA, USA
IONEX Research
Lafayette, CO, USA
Cabot Norit Act. Carbon
Marshall, TX, USA
Coal
Coconut
Coal
6 x 16
12 x30
8 x 16
6 x 12
Yesa
No
No
0.6-0.7
0.4-0.6
0.51
a Impregnated with copper, silver, zinc, molybdenum and triethylenediamine (TEDA).
The IONEX 03-001 carbon is an activated coconut shell-based activated carbon. This
type of carbon usually has greater adsorption capacity than a coal-based (activated) carbon (such
as ASZM-TEDA and Vapure 612) because the coconut shell-based carbons typically have more
micropores per unit mass and greater surface area. Also, a carbon with a smaller particle size
(higher mesh numbers) means better dynamic adsorption performance due to a higher mass
transfer rate. Therefore, better adsorption performance is expected for the ASZM-TEDA (12 x
-------
30 mesh) relative to the other ASZM-TEDA (6x16 mesh), IONEX 03-001 (8x16 mesh) or
Vapure 612 carbon (6 xl2 mesh) carbons.
2.2 Testing Apparatus
The test system, as illustrated schematically in Figure 1, consisted of a temperature (T)
controlled chamber, challenge vapor generator, and upstream and downstream sampling ports.
Temperature
Controlled
Circulating
Bath
Regulator
Compressed
House Air
Carbon
Filter
Vent
Adsorption Test
Carbon Bed
Figure 1. Schematic of the test system used for carbon performance evaluation.
The temperature-controlled chamber housed the carbon bed holders. The chamber was
constructed of Lucite® material and had a radiator (Model K84, Beacon Morris, Westfield, MA,
USA) mounted to the top that was used to heat or cool the air within the chamber. The radiator
was equipped with a blower to circulate air from within the chamber through the radiator. A
temperature-controlled water bath (NESLAB RTE 740, Thermo Scientific, Waltham, MA, USA)
was used to circulate the heat transfer fluid through the radiator continuously. RH in the
-------
challenge air stream was controlled at the target values, while the RH in the temperature-
controlled chamber was not controlled.
2.2.1 Air Flow Handling
Trace amounts of vapor and paniculate impurities might exist in the house air supply.
Therefore, prior to humidification, the house air was filtered using a carbon filter and a high-
efficiency particulate air (HEPA) filter, with the carbon filter removing vapor phase impurities
and the HEPA filter removing 99.97 % of particulate impurities. As shown in Figure 1, the
challenge vapor produced by the vapor generator was diluted with the humidified, scrubbed
house air to obtain the desired challenge vapor concentration and RH prior to entering the
temperature-controlled chamber. A Nafion® tube (Perma Pure, Toms River, NJ, USA) was used
to add humidity to the challenge atmosphere. The clean air stream was then split into two
streams. One stream was passed through the humidifier, and the second remained dry. Needle
valves were used to control the flow rates of dry and humidified air. The flow rates were
measured using calibrated mass flow meters (MFMs). The ratio of dry to humidified dilution air
was adjusted to obtain the target relative humidity. The flow through the carbon bed was set to 9
liters per minute (Lpm). This flow was derived from a 12.0 centimeters/second (cm/s) face
velocity through a 4-cm diameter carbon bed. Such flow conditions yield a 0.2 to 0.3 s contact
time between the chemical contaminant and the carbon using 2.5 to 3.5 cm bed depths.
2.2.2 Temperature and Relative Humidity
The temperature and RH of the challenge gas were measured before addition of the
challenge GB or HD using a T/RH probe at the location shown in Figure 1. The temperature of
the challenge gas was also measured after addition of the challenge gas at the indicated locations
before and after the carbon bed, as shown in Figure 1. Because agent vapor may foul the RH
sensor, the final RH in the challenge gas delivered to the carbon bed was calculated based on the
RH-T measurement before agent addition and temperature measurement after the agent addition
upstream of the carbon bed.
-------
As shown in Figure 1, the air from the humidifier was split into two streams, referred to
as the "conditioning air plenum" and the "challenge plenum". The agent vapor was introduced
only into the challenge plenum. Air from the conditioning air plenum was drawn through the
carbon bed during carbon bed pre-conditioning. Air was drawn from the challenge plenum
during the adsorption test. A two-way valve was installed at the inlet of each carbon bed to
allow the challenge concentration to be established and verified prior to challenging the carbon
test bed during the adsorption test or pre-conditioning test, respectively.
Flow through the carbon bed was initially controlled by a vacuum pump with an in-line
needle valve and measured using a calibrated MFM. Later tests used a calibrated mass flow
controller (MFC) in line with a vacuum pump. Sampling ports upstream and downstream of the
carbon bed allowed for measurement of the challenge and effluent vapor concentrations,
respectively. The flow rate through the carbon bed was monitored and recorded continuously
during a test. The temperature, RH and carbon bed pressure drop measurements were captured
electronically by a data logger for the duration of the test.
2.2.3 Carbon Bed
The carbon bed holder, as shown in Figure 2, was fabricated with inert anodized
aluminum. The inner diameter (ID) of the carbon holder was 4.0 cm, which was determined
based on American Society for Testing and Materials (ASTM) D5160, Standard Guide for Gas-
Phase Adsorption Testing of Activated Carbon (ASTM, 2008). To minimize wall effects, ASTM
D5160 requires the carbon bed diameter to be at least 12 times the diameter of the largest carbon
granule size. The largest carbon granule size of the three carbon types tested was 3.3 millimeters
(mm) (6 mesh), which led to a minimum carbon bed diameter of 4 cm (3.3 mm times 12). Larger
bed diameters would further reduce the impact of wall effects. However, the amount of carbon
used in these types of studies should be limited to avoid use of significant quantities of CWA
during the adsorption phase.
The carbon bed depth was initially set to 2.5 cm, which was expected to be larger than
the anticipated critical bed depth. The bed depth was later increased to 3.5 cm to delay
breakthrough of agent for some of the carbons tested.
-------
To challenge measurement
Upper bed pressure drop
Upper bed temperature
Location of
carbon bed
Wire Mesh
Lower bed temperature
Lower bed pressure drop
To downstream effluent measurement
Figure 2. Photograph of the carbon bed holder.
As shown in Figure 2, the inlet of the carbon holder was tapered so that there was a
gradual transition to the 4.0 cm ID. The carbon was contained between two stainless steel wire
meshes. Temperature and pressure drop measurements were taken at the positions noted above
and below the carbon bed. Data were recorded using HOBO pressure transducers/data loggers
(Onset Computer Corp., Bourne, MA, USA). This configuration was dictated by the cell design,
with only four ports available for five process measurements. The challenge sample port was
located 2 cm upstream of the carbon bed. The effluent sample port was located approximately
15 cm downstream of the carbon bed holder. Both sample probes extended beyond the wall of
the carbon bed holder so that the sample was collected from the center of the flow stream. The
sample lines for monitoring the challenge and effluent gases were 1/8-inch (in) outer diameter
(OD) Teflon lines. To minimize the potential for adsorption of agent during transport, the
sampling lines were heat-traced.
2.2.4 CWA Vapor Generation
The target test challenge concentration was 1,500 milligrams/cubic meter (mg/m ) of GB
and 500 mg/m3 HD. The GB concentration was based on a calculated (maximum) GB vapor
-------
9 9
concentration following a hypothetical release of 1 liter of liquid GB in a 186 m (2000 ft )
(office) area. A similar HD amount released would result in a saturated vapor condition (at room
temperature), so the HD concentration was set below the saturated vapor pressure
(approximately 660 mg/m3 for HD at room temperature).
Two different chemical vapor generating methods were employed to generate the CWA
vapor. A sparging system (Method A) described below was used for all GB testing except for the
ASZM-TEDA (12 x 30 mesh) tests while a syringe pump-based infusion system (Method B) was
used for all HD testing and the aforementioned GB tests with ASZM-TEDA (12 x 30 mesh).
Method A was not suitable to generate the high HD concentration at the 9 Lpm flow rate, hence
the agent delivery method was switched. Since the GB and HD challenge concentrations were
measured continuously, there is no impact on the effluent concentration results when comparing
results obtained with either method.
2.2.4.1 Sparging System (Method A)
As illustrated in Figure 3, the GB challenge gas was generated by sparging dry filtered
house air through neat liquid GB. The system consisted of a custom-built glass sparger followed
by a custom-built glass droplet trap. The GB-laden air exiting the sparger was passed through
the droplet trap to remove any entrained liquid. The droplet trap was filled with glass beads to
provide additional surface area for a stable vapor output. Both the sparger and droplet trap were
contained in a temperature-controlled circulating bath. Depending on target challenge
concentrations, the water bath was operated at a predetermined temperature to generate sufficient
agent vapor for subsequent dilution. The vapor stream from the generator was diluted with
humidified air to meet the concentration and humidity requirements.
-------
Regulator
H
Carbon
Piltcir
i liter
1
1
1
I
\J
T_J
r<* -4_H
MFM
HEPA
Ciltar •-
i iner '
Glass
Sparger
i
=J
i
_i
|
1
I—.
1
LJ
I
i
i
i
i
Glass |
Droplet i
Trap
Water Bath
L
Figure 3. Schematic of vapor generation system.
2.2.4.2 Syringe Pump Vapor Infusion (Method B)
To Temperature
Controlled Chamber
In Method B, HD and GB challenge gases were generated using a liquid infusion vapor
generation method requiring a syringe pump (Pump 11 Elite, Harvard Apparatus, Holliston, MA,
USA), a heated transfer line, and an air source. A schematic of the vapor infusion challenge
generation system and how it interfaces to the test chamber is shown in Figure 4. In this method,
the agent vapor was generated by infusing (on the order of several microliters [|iL]/minute) of
the CWA liquid into a heated transfer line via valve #8. The heated zone, shown as the shaded
circle in Figure 4 just upstream from valve #8, consisted of stainless steel tubing wrapped in
pressure sensitive heating tape and insulated with a double layer of fiberglass cloth tape. The
agent vapor was directed through a three-way valve (valve #7 in Figure 4) into the challenge
plenum where it was diluted with conditioned air (depending on the test condition being used) to
achieve the target challenge concentration, monitored via gas chromatography (GC) with flame
ionization detector (FID) on the back end of the challenge plenum prior to venting the system.
Once the target challenge concentration was verified, agent vapor was directed through the test
cell using valve #4.
-------
MFC
] > Carbon
trap/Vent
Heated zone
monitored with
thermocouple/meter
Syringe
Pump
Carbon trap/Vent
Figure 4. Schematic of the liquid infusion vapor generation system.
Photographs of the syringe pump and heated line interface are shown in Figure 5.
Infusion of the CWA liquid into a heated transfer line occurred via valve #8. The temperature
was controlled by setting the power supplied to the heating tape. The air temperature within the
heated agent transfer line was monitored using a thermocouple inserted prior to the agent
introduction point. For FID vapor generation, the temperature of the heated zone was maintained
at a temperature below the boiling point (between 140 and 150 degrees Celsius [°C]). HD begins
decomposing near its boiling point of 218 °C. For GB vapor generated using this method, the
temperature was maintained at approximately 130 °C; the boiling point for GB is 158 °C.
10
-------
Figure 5. Photographs of the syringe pump vapor infusion apparatus: (lower)
programmable syringe pump with loaded syringe, connected to a transfer line, leading to
(upper) valve 8 connection to heated transfer line.
2.3 Analytical Methods
Agent vapor in the effluent stream was measured using a MINICAMS® continuous air
monitor (OI Analytical, College Station, TX, USA) equipped with a sample loop injector and an
FID or a flame photometric detector (FPD). The MINICAMS® is an automatic, near-real-time
continuous air monitoring system using gas chromatography and sample collection with a solid-
adsorbent pre-concentrator or fixed-volume sample loop. The minimum detection limit for the
MINICAMS is analyte/calibration dependent, with the minimum instrument response at a level
of the short term exposure limit (STEL) (GBsiEL= 0.0001 mg/m3).
The agent challenge concentration was measured using an Agilent 5890 GC equipped
with an FID (Agilent Technologies, Santa Clara, CA, USA) for HD testing, a 1 milliliter (mL)
sample loop, and a heated sample line. The GB challenge concentration was measured using the
FPD.
During testing, samples of the challenge and carbon bed effluent were analyzed without
dilution. Typical run times for the MINICAMS and GC were approximately 6 minutes (min)
and 8 min, respectively, with both instruments running continuously during the adsorption phase.
11
-------
Sampling of the challenge concentration by GC was discontinued shortly after the start of
desorption phase.
Prior to each test, calibration curves were generated for both the MINICAMS® and the
GC using a set of standards of various concentrations. At the conclusion of a test, a one-point
calibration check verification (CCV) sample was analyzed for each instrument.
2.4 Test Procedures
Tests were performed following Battelle's Standard Operating Procedure (SOP), entitled
Evaluation of the Activated Carbon Beds with Chemical Agent Vapors (Battelle HMRC SOP X-
283), which was reviewed and approved by Battelle management and safety representatives.
2.4.1 Carbon Bed Pre-conditioning
Prior to the adsorption/desorption test, each carbon bed was loaded in the test cell as
depicted in Figure 6 and placed in the chamber to pre-condition. The purpose of this step was to
allow the carbon bed to achieve equilibrium under the environmental conditions (i.e., T/RH) to
be used in the agent testing. Appendix A to this report describes the research efforts to
determine the minimum equilibrium time based on measurement of weight changes of the carbon
bed with time due to change in T and RH. The main outcome of this effort was that a 16 hour (h)
equilibrium time ensures equilibrium at all T and RH conditions for all carbon beds tested.
Pre-conditioning was conducted by flowing air from a dedicated clean air source (at the
target T and RH) through the carbon bed at the test flow rate overnight (i.e., >16 h).
12
-------
Figure 6. Loading the carbon test cell with IONEX 03-001 carbon (8 x 16 mesh): (A) mesh
screen in bottom cell piece and O-ring in the well at the top of the cell, (B) pre-weighed
carbon loaded into bottom cell piece, (C) cell bottom with level and packed loaded carbon,
(D) mesh screen on top of carbon bed, and (E) top cell piece screwed on using locking ring.
2.4.2 Adsorption and Desorption Testing
After the pre-conditioning phase, the test cell was connected to the agent challenge air
source, and the pre-test agent delivery system (Method A or B) was started to ensure that the
target challenge concentration was achieved. A photograph of the typical test chamber starting
configuration is shown in Figure 7.
13
-------
I
Figure 7. Typical test chamber configuration for carbon bed adsorption and desorption
testing.
The challenge concentration, flow rate, and temperature were established and recorded
prior to initiating a test. After target conditions were established, challenge flow was introduced
to the carbon bed, which defined the start of the test: t = 0 min. All recorded test event times
were relative to time t = 0 min. Challenge and carbon bed effluent measurements were made
every eight and six minutes, respectively.
An adsorption test proceeded until target breakthrough concentration of the designated
chemical agent was reached. At this point, desorption test was started by turning off the agent
vapor supply (via Method A or B) while temperature and air flow (no agent) through the carbon
bed remained the same as during the adsorption test. The subsequent desorption of chemical
agent from the activated carbon bed continued to be monitored until steady state in the agent
14
-------
effluent concentration was reached. If a steady state had not been achieved within 12 h (or
overnight) after the agent vapor challenge ceased, desorption test was stopped.
2.5 Test Matrix
The complete test matrix is presented in Table 2. For each carbon, described in Section
2.1, tests consisted of a reference adsorption / desorption test at 25 °C and low (< 15 % RH)
humidity, a high temperature (55 °C) and low humidity test, and a high temperature (55 °C) and
high humidity (50 % RH) test. Occasional replicates were included to assess reproducibility of
adsorption and desorption results. The inherent difficulty of using CWAs in large quantities
(milliliters of agent consumed per test) prevents a more thorough research effort with statistically
sufficiently numbers of replicates per test point.
The initial carbon bed depth for all studies was set at 2.5 cm to keep the amount of
carbon as low as possible. Results from the first ASZM-TEDA (6x16 mesh) were interpreted as
signifying that the critical minimum bed depth had not been reached, hence larger bed depths
were tested. After two increases in carbon bed depth, a second carbon, IONEX 03-001 (8x16
mesh) was tested. All further GB testing was conducted at the thicker 3.5 cm carbon bed depth.
A similar approach was used for testing with HD. For FID, no immediate breakthrough occurred
for the 2.5 cm carbon bed depth, and the depth was not modified.
15
-------
Table 2. Complete test matrix.
Carbon Bed
Chemical Carbon Bed Temperature
Agent Depth (°C)
Number
of Tests
ASZM-TEDA
(6 x 16 mesh)
IONEX03-001
(8 x 16 mesh)
Vapure 612
(6x12 mesh)
ASZM-TEDA
(12x 30 mesh)
IONEX03-001
(8 x 16 mesh)
ASZM-TEDA
(12x 30 mesh)
ASZM-TEDA
(6 x 16 mesh)
GB
GB
GB
GB
HD
HD
HD
2.5
3.0
3.5
3.5
3.5
2.5
2.5
2.5
2.5
25 ±2
25 ±2
55 ±2
25 ±2
55 ±2
25 ±2
55 ±2
25 ±2
55 ±2
55 ±2
25 ±2
55 ±2
55 ±2
25 ±2
Dry (i.e., <15 %)
Dry (i.e., <15 %)
Dry (i.e., <15 %)
Dry (i.e., <10 %)
Dry (i.e., <10 %)
Dry (i.e., <10 %)
Humid (50 ± 10 %)
Dry (i.e., <10 %)
Dry (i.e., <10 %)
Humid (20 ± 10 %)b
Dry (i.e., <10 %)
1
1
2a
2
2
2
2
1
1
1
1
1
1
1
1
1
a Includes one incomplete test that was truncated due to significant baseline drifting of the MINICAMS®/FID.
b For the ASZM-TEDA (12x30 mesh) hot/humid test with HD vapor, the target % RH was lowered to 20 % due
condensation observed in the MINICAMS® sampling MFC during the previous testing of IONEX 03-001 carbon
under those test conditions.
to
16
-------
3.0 QUALITY ASSURANCE AND QUALITY CONTROL
3.1 Data Quality Objectives and Results
The quantitative assessment of the breakthrough curve and the subsequent desorption
curve at a given temperature and relative humidity is affected by uncertainty in measurements of
challenge and effluent GB and HD concentrations, flow rate through the carbon bed, carbon
amount loaded into the carbon bed, and temperature and relative humidity of the system. The
uncertainty is defined as relative percentage of difference (%RPD) from the standards. The
critical data quality objectives, data quality indicators, and results for these measurements are
summarized in Table 3.
GB or HD concentrations in the effluent air stream were measured using the
MINICAMS®/FID or the MINICAMS®/FPD. The challenge GB and HD concentrations were
measured using GC/FPD and GC/FID, respectively. Prior to or after each test, calibration curves
were generated for both the MINICAMS® and GC using a set of standards of various
concentrations. At the beginning and the conclusion of a test, a one-point calibration check was
performed for each analytical method. The MINICAMS operational parameters for detection of
GB and HD are presented in Appendix B.
As summarized in Table 3, quality control (QC) requirements were met for the
measurements of carbon bed weight, flow rate through the carbon bed, temperature, RH, and
pressure drop across the carbon bed. For GB challenge concentration measurements, all tests
met the QC requirement in pre-test one-point calibration checks (acceptance criterion is
RPD ± 25 %). The QC requirement (±25 %) was also met in post-test one-point calibration
checks for all tests except one test that showed an RPD of ±30 %. The post-test lower response
of this CCV may suggest that the actual challenge concentration may have been 5 % higher than
recorded. The breakthrough curve (correction) would therefore have shifted to longer times. This
correction is relatively minimal, and its impact is therefore considered to be minimal.
Five tests used the MINICAMS®/FID to measure effluent GB concentration, which
included all four tests with the ASZM-TEDA (6x16 mesh) carbon, and Run 1 of the IONEX
03-001 carbon test at 25 °C/dry conditions. For these tests, the QC requirement was met in all
pre-test one-point calibration checks. The QC requirement was also met in the post-test one-
point calibration checks for two of the five tests. The post-test one-point calibration check was
17
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not conducted with the other three tests due to significant baseline drifting of the
MINICAMS®/FID. The impact of these missed checks is relatively low since the data presented
are limited to the adsorption phase of the experiment.
Nine tests used the MINICAMS®/FPD to measure effluent GB concentration, which
included four tests with the Vapure 612 carbon, three tests with the IONEX 03-001 carbon, and
two tests with the ASZM-TEDA (12 x 30 mesh) carbon. QC requirements were met for most of
these tests. Two exceptions were: (a) Run 2 with the IONEX 03-001 carbon at 55 °C/dry
conditions, where the RPDs were 44 and 54 % in the pre-test and post-test one-point calibration
checks, respectively; and (b) Run 2 with the IONEX 03-001 carbon at 25 °C/dry conditions,
where the pre-test one-point calibration check was not conducted. Results from Run 2 with the
IONEX 03-001 carbon at 55 °C/dry conditions were also confounded by residual GB in the
effluent sample line. Results from this Run 2 are presented in Section 4.3.2. However, further
interpretation of the IONEX 03-001 carbon at 55 °C/dry conditions is limited to data observed
for Run 1. The impact of the RPD values exceeding 25 % is negligible. The impact of the
missing pre-test one-point calibration check for Run 2 with the IONEX 03-001 carbon at 25
°C/dry conditions on the data quality is also considered to be minimal. The RPD value for the
post-test one-point calibration check was reported well within the ±25% range (actual 1 %
deviation from expected). The impact of the missed pre-test calibration check is deemed
minimal.
All seven tests used the MINICAMS /FID to measure effluent HD concentration. For
these tests, the QC requirement was met in all pre-test one-point calibration checks. The QC
requirement was also met in the post-test one-point calibration checks for all HD tests but one.
The post-test one-point calibration check for the 55 °C/humid IONEX 03-001 test was not
conducted due to sampling flow failure (condensation in lines). This failure is discussed in
Section 4.5.1. Solid sorbent tubes (SSTs) were obtained at the conclusion of the challenge
period to determine the effluent concentration.
18
-------
Table 3. Critical data quality objectives and results.
Parameter
Challenge
Concentration
(mg/m3)
Measurement
Method
GC-FPD(a)
(Agilent 5890)
QC Requirement
Data Quality Indicator Acceptable Uncertainty Frequency of Calibration
(%RPD) Check
One-point calibration
checks must agree within
±25 % RPD(d)
Challenge
Concentration
(mg/m3)
Effluent
Concentration
(mg/m3)
GC-FID
(Agilent 5890)
MNICAMS®/FID(b)
(OI Analytical)
Effluent
Concentration
(mg/m3)
Carbon Bed
Weight (g)
(OI Analytical)
Microbalance
Check balance used with
standard weight set, agree
within ±5 %
±25 %
±2%
Full calibration at the
beginning of testing
campaign, daily one-point
calibration check and a one-
point check at the conclusion
of the test. Recalibrations
made as needed, indicated by
one point calibration checks.
Full calibration before each GB test
GB pre-test one-point check: met QC requirement.
GB post-test one-point check:
o RPD < ±30% for Run 2 with the IONEX 03-001
carbon at 25 °C/dry
All other GB tests met QC requirement
Semiannually and beginning
of testing
Full calibration prior to HD testing
HD pre-test one-point check: met QC requirement.
FfD post-test one-point check: met QC requirement
Full calibration prior to GB and HD testing
GB and HD pre-test one-point check: met QC requirement.
GB and HD post-test one-point check:
o Two GB tests met QC requirement: ASZM-TEDA
(6x16 mesh) carbon with 2.5 cm bed and Run 1
of the IONEX 03-001 carbon at 25 °C/dry
o Not conducted for other (3) GB tests due to
significant baseline drift
o All other GB tests and all HD met QC requirement
Full calibration prior to GB testing
o Pre-test one-point check: Not conducted for Run 2
with the IONEX 03-001 carbon at 25 °C/dry
o RPD < ±44 % for Run 2 with the IONEX 03-001
carbon at 55 °C/dry
o All other tests met QC requirement
Post-test one-point check:
o RPD < ±54 % for Run 2 with the IONEX 03 -
001 carbon at 55 °C/dry
o All other tests met QC requirement
Met QC requirement
19
-------
Parameter
Flow Rate
through
Carbon Bed
(liters per
minute, Lpm)
T(°C)
RH (%)
Carbon Bed
AP
(inofH2O)
Measurement
Method
Mass flow controller
Thermocouple
T/H Probe
Pressure Transducer
Data Quality Indicator
Compare against standard
dry gas meter reading,
must agree within ±5 % of
reading
Compare against
calibrated thermometer
before evaluation testing,
must agree within ±2 °C
Compare against
calibrated hygrometer
before evaluation testing,
must agree within ±10 %
of reading, or ±5 % RH,
whichever is larger
Compare against NIST*-
traceable calibrated gauge
before evaluation testing,
must agree within ±10 %
of reading
QC Requirement
Acceptable Uncertainty
(%RPD)
±5%
±2°C
±5%
±10 %
Frequency of Calibration
Check
Annually and beginning of
testing
Result
• Met QC requirement
• Met QC requirement
• Met QC requirement
• Met QC requirement
(a) Revised from the original GC/FID, as documented in Test/QA Plan Amendment 2.
(b) The MINICAMS®/FID was used to measure effluent concentration for the following tests: GB: all ASZM-TEDA (6x16 mesh) carbon tests, Run 1 of
the IONEX carbon at 25 °C /dry conditions; HD: all tests
(c) The MINICAMS®/FPD was used to measure effluent concentration for GB tests, including: all Vapure 612 carbon tests, IONEX 03-001 carbon tests
at 55 °C/dry, Run 2 of the IONEX 03-001 carbon at 25 °C/dry, and both ASZM-TEDA (12 x 30 mesh).
(d) Revised the original ±15 % RPD, as documented in Test/QA Plan Amendment 2.
*National Institute of Standards and Technology
20
-------
3.2 Equipment Calibrations
The instrumentation used for the analyses is identified in Section 2.3. The required
analytical equipment was maintained and operated according to the quality requirements and
documentation of the HMRC. The GC and MINICAMS® systems used for measurement of the
agent challenge concentration and effluent stream concentration, respectively, were either
calibrated at the beginning of each test condition (multipoint calibration curve) or calibration was
verified with a single pre-test standard. Breakthrough tests were concluded with a single post-test
check point for each system except as noted in Table 3.
The GC was maintained in calibration such that that the coefficient of determination (r2)
from the linear regression analysis of the calibration curve was more than 0.98. GC calibration
curves (3-4 calibration points) were generated around the nominal 1500 and 500 mg/m3
challenge concentrations for GB and HD, respectively.
The MINICAMS® was calibrated initially at the start of a testing period for a specific
chemical agent (GB or HD) and then recalibrated as needed based on the response to the CCV
standard prior to each test. MINICAMS® calibration curves (4-8 calibration points) were
generated depending on anticipated effluent agent concentrations.
3.3 Technical System Audit
The QA Manager performed two technical systems audits (TSAs) during the performance
of the adsorption/desorption testing. The purpose of the TSA was to ensure that testing was
performed in accordance with the test/QA plan and applicable SOPs. In the audit, the QA
Manager reviewed the sampling and analysis methods used, compared actual test procedures to
those specified in the test/QA plan, and reviewed data acquisition and handling procedures. Both
audits observed testing of the carbon bed system with GB. Several items were noted during the
audit and corrected before additional work was performed.
21
-------
3.4 Data Quality Audit
6A Data Quality Audit
For this work, the QA Manager audited at least 10 % of the investigation data and traced
the data from initial acquisition, through reduction and statistical comparisons, to final reporting.
All data analysis calculations were checked.
22
-------
4.0 TEST RESULTS
4.1 Equilibrium Time
Prior to the chemical agent adsorption/desorption testing, each carbon bed was
preconditioned to achieve equilibrium at the environmental conditions (i.e., temperature and RH)
to be used in the agent testing. The preconditioning was conducted by flowing air (at the target
temperature and relative humidity) through the carbon bed until water vapor adsorption
equilibrium is achieved. To determine the time required to achieve water vapor adsorption
equilibrium, a set of equilibrium tests was conducted for all carbon beds at three test conditions
of 55 ± 2 °C and 50 ± 5 % RH, 55 ± 2 °C and dry (<15 % RH) and 25 ± 2 °C and dry. Those
results are presented in Appendix A.
4.2 Preliminary Testing with GB Surrogate
Before the test matrix in Table 2 was implemented, preliminary testing was conducted to
ensure system safety and operation. A safety dry run (no carbon present) was conducted with
dimethyl methylphosphonate (DMMP) at an average challenge concentration of 1,570 mg/m3.
Immediate DMMP breakthrough was detected in the test. To ensure that the immediate DMMP
breakthrough was not due to any bias with the test system, a test was conducted with a carbon
(ASZM-TEDA 12^30 mesh) that was expected to have a longer breakthrough time due to much
smaller particle size. No breakthrough of DMMP was detected during the 70 min exposure at a
challenge concentration of 1,220 mg/m3. The result verified that the test system was functional.
4.3 Results for GB
In initial GB tests, the effluent concentrations were measured by the MINICAMS®/FID.
After several tests, the MINICAMS®/FID baseline started drifting off scale, especially during
overnight desorption. The effluent concentration measurement was then switched to the
MINICAMS®/FPD. No baseline drift was observed with the MINICAMS®/FPD, indicating that
23
-------
whatever in the carbon bed effluent that had interfered with the FID baseline did not affect FPD
analysis.
4.3.1 ASZM-TEDA (6 x 16 Mesh) Carbon Tests
Four GB tests were conducted with ASZM-TEDA carbon at 25 °C/dry conditions and a
target challenge concentration of 1,500 mg/m3. Immediate breakthrough was measured with a
2.5 cm depth ASZM-TEDA (6 x 16 mesh) carbon bed at target challenge of 1,500 mg/m3 and 25
°C/dry conditions. This result implied that the critical bed depth at the test conditions was
deeper than the anticipated 2.5 cm bed depth. The bed depth was enhanced to 3.0 cm and finally
3.5 cm to generate data meaningful to the project.
The GB challenge concentrations measured in the four tests are presented in Appendix C
(Figures C-l to C-4). Steady challenge concentrations were achieved in the tests, with standard
deviations less than 10 % of the averages. The flow rate, temperature, and RH recorded during
the tests were plotted versus time, and the plots are presented in Appendix C. As demonstrated
in the plots (Figures C-l to C-4), the flow rate, temperature, and RH were steady throughout the
adsorption/desorption tests of the ASZM-TEDA carbon. Pressure drop across the carbon bed
was not recorded during these tests because the pressure transducer was not operating properly.
The lack of pressure measurement does not have a direct impact on the measurements of the
breakthrough and desorption curves.
The measured breakthrough and desorption curves at different bed depths are presented
in Figure 8. The adsorption time plotted in Figure 8 was normalized to the target challenge
concentration of 1,500 mg/m3, so that the breakthrough curve from each individual test could be
compared directly, even if there were small (< ± 20 %) variations in the average challenge
concentrations among the tests. For example, if the measured average challenge concentration
for a test was 1,350 mg/m3, the target was 1,500 mg/m3, and the actual adsorption time was t
(min), then the normalized (plotted) adsorption time would be t (min) x 1,350 mg/m3/l,500
mg/m3 = 0.9 x t (min). The effluent concentrations presented in Figure 8 were measured by the
MINICAMS®/FID. Two tests were conducted at a 3.5 cm bed depth. The first run was stopped
at 78 min into adsorption, due to significant baseline drifting of the MINICAMS®/FID (data not
shown).
24
-------
As expected, the breakthrough time increased greatly with the breakthrough curve shifted
to the right (i.e., longer times) as bed depth increased from 2.5 to 3.0 cm. Further increased bed
depth to 3.5 cm, however, did not shift the breakthrough curve, with the breakthrough curves of
the 3.5 cm beds overlapping with the breakthrough curves of the 3.0 cm bed. Overlapping
breakthrough curves were not expected because the 17 % extra carbon in the 3.5 cm bed should
generate longer breakthrough times. The test system and the recorded testing parameters,
including flow rate, temperature, RH, and challenge/effluent concentrations, were checked, and
no problems were identified. The reason for the unexpected behavior remains unknown.
Desorption of GB was observed after the challenge GB was ceased, and clean air was
introduced through the carbon beds at the flow rate and T/RH conditions equivalent to the
adsorption test. As shown in Figure 8, the desorption concentrations initially decreased quickly,
reaching approximately 10 to 16 % of the peak concentration (i.e., the final breakthrough
concentration before switching to desorption) within the first 30 min. The desorption
concentration then decreased gradually and finally leveled off (with a slightly decreasing trend).
The leveled off values appeared to be increasing with increased GB loading (or exposure period)
during adsorption, with leveled off values of 0.5, 0.7, and 3 mg/m3 measured, respectively, for
the tests with 2.5, 3.5, and 3.0 cm carbon beds that had been exposed to GB for 60, 153, 196 min,
respectively.
The desorption process persisted at a concentration three to four orders of magnitude
higher than the STEL of GB (i.e., 0.0001 mg/m3 for GB) for hours. For example, after 9 h of
desorption, the effluent concentration was still at a level of approximately 3 mg/m3 for the test
with the 3.0 cm carbon bed.
Only small quantities of adsorbed GB, however, were desorbed. For example, for the test
with the 3.0 cm carbon bed, the amount of GB adsorbed was estimated to be 2.6 grams (g), based
on measured challenge and breakthrough curves, flow rate, and adsorption period (196 min).
The amount of GB desorbed after 5.5 h of desorption was estimated to be 0.016 g, based on
desorption curves and flow rate. Therefore, only 0.6 % of adsorbed GB was desorbed in the 5.5
h desorption.
25
-------
60 -,
"? 50-
p
|40-
"c 30-
0 20-
GQ
O
| 10-
m o-
c
Normalized time (h)
)123456789
• D
•" jT
' 1
) 1;
•
•
o
A.
/; \
A
\
20 2^
- n 2.5cm
• o 3.0cm
^ A 3.5cm
^
^^W
^^ftt&gm
10 360 4i
rfff^o*
30
Normalized time (min)
Figure 8. Breakthrough and desorption curves at 25 °C/dry and varying bed depth for
ASZM-TEDA (6 x 16 mesh) carbon. Desorption phase starts at the transition from solid to
open symbols.
4.3.2 IONEX 03-001 (8 x 16 Mesh) Carbon Tests
All four tests with the IONEX 03-001 carbon were conducted with bed depth of 3.5 cm.
Duplicate tests were conducted at 25 °C/dry and 55 °C/dry conditions and target challenge
concentration of 1,500 mg/m3. The GB challenge concentrations measured in the tests are
presented in Appendix C (Figures C-5 to C-10). As shown in Appendix C, steady challenge
concentrations were achieved for two tests, Run 2 at 25 °C/dry (Figure C-6) and Run 1 at 55
°C/dry (Figure C-7). For these two tests, the standard deviations of the challenge were less than
10 % of the averages. For the first run at 25°C/dry, as shown in Figure C-5, the challenge
concentration began to decrease at 240 min as the GB source in the vapor generator was
depleted, and the concentration reduced to 150 mg/m3 at 330 min. Airflow through the carbon
bed was stopped and the test restarted the next morning with a replenished vapor generator.
During the second run at 55 °C/dry, as shown in Figure C-8, significant variation in the
challenge concentration was observed, with the standard deviation over 40 % of the average.
26
-------
As demonstrated in Figures C-5 to C-10, the flow rate, temperature, and RH were steady
throughout the adsorption/desorption tests of the IONEX 03-001 carbon. Pressure drop across
the carbon bed was not recorded during the two tests at 25 °C/dry conditions because the
pressure transducer was not operating properly. As shown in Figures C-8 and C-10, the pressure
drop was stable during the tests at 55 °C/dry conditions, with average pressure drop of 0.23
inches of water and standard deviation less than 1.5 % of the average.
The measured breakthrough and desorption curves for the IONEX 03-001 carbon at 25
°C/dry conditions are presented in Figure 9. The effluent GB concentration was measured by the
MINICAMS®/FID for the first run and by the MINICAMS®/FPD for the second run. The
breakthrough curve of Run 1 shifted to the right, most likely due to suspending of the adsorption
test overnight. Results from Run 1 were therefore not considered to be representative of a single,
continuous, adsorption GB test. Only the results from Run 2 at the 25 °C/dry conditions were
used for further comparison. Note that the initial breakthrough after approximately 180 min
occurred for both runs.
Normalized time (h)
0 4 8 12 16 20
/in
Effluent GB Concentration (mg/m3)
-^ K3 CO J
O O O O C
_ i . i . i . i
•
•
•
— 4
) 2'
. •
• °
• o
•
n
' D« °
n
• n
. a o
n O
' & ^o
1 V
: X
•
-/
• ° 25°CRun1
° 25 °C Run 2
^^^^nrnmam
fflnilCTTllTirnTTiiiiiiiiiQjjiuinn
iiiniiiDninKnnMniininiiM
10 480 720 960 1200
Normalized time (min)
Figure 9. Breakthrough and desorption curves of the IONEX 03-001 carbon at 25 °C/dry.
Desorption phase starts at the transition from solid to open symbols.
27
-------
The IONEX 03-001 (8 x 16 mesh) carbon demonstrated significantly better adsorption
performance than the ASZM-TEDA (6x16 mesh) carbon. For example, as measured in the Run
2 at 25 °C/dry conditions, the effluent GB concentration held at <0.04 mg/m3 until t = 80 min
while for the ASZM-TEDA (6^16 mesh) carbon the effluent concentration reached 0.04 mg/m3
after only 10 min into the adsorption test.
Similar to the results observed in the ASZM-TEDA tests, a quick reduction in desorption
concentration occurred in the initial stage of desorption. The desorption concentration then
leveled off (with a slightly decreasing trend), with a desorption concentration of approximately 4
mg/m3 after desorption for over ten hours.
Figure 10 presents the breakthrough and desorption curves for IONEX 03-001 carbon at
55 °C/dry conditions. As shown in Figure 10, for Run 2, the measured effluent concentration
reduced constantly during the first 250 min of adsorption, with concentration reduced from
approximately 1.0 to 0.02 mg/m3. The effluent GB concentration measured during the period
was believed to be artificial and due to residual GB in the downstream pipelines. Prior to this
test, the system was tested with a shallow carbon bed at 55 °C/50 % RH to investigate the
potential formation of HF, and some GB may have remained in the downstream pipeline after the
test. Results from this duplicate run were considered to be biased and were not used in the
comparison with other GB IONEX adsorption data.
At 55 °C/dry conditions, the IONEX 03-001 carbon demonstrated good adsorption
performance. For example, during Run 1, the effluent GB concentration remained at <0.04
mg/m3 for the first 170 min. The effluent concentration then increased slowly to 0.8 mg/m3 at
340 min when the adsorption test was stopped.
Different from desorption at 25 °C/dry, the desorption concentration increased slowly
and constantly during the desorption test, with the concentration increased from 0.8 mg/m3 at the
startup of desorption to 1.4 mg/m3 after 10 hours of desorption (Run 1).
Similar to the tests with the ASZM-TEDA carbon, only a small quantity of the adsorbed
GB was desorbed. For example, only 1 % and 0.1% of the adsorbed GB was estimated to be
desorbed over ten h of desorption for the tests at 25 °C/dry (Run 2) and 55 °C/dry (Run 1)
conditions, respectively.
28
-------
Normalized time (h)
0 4 8 12 16 20
0 Q
CO™^
E
g 1.5-
5 -
| 1.0-
^0
CD 0.5-
^— <
1 -
e
LLJ
00-
h
.
•
•
\
^X
;
fft
W • ^Pn
*3C j
. -^r\f
^^^
^
• ° 55°CRun1
° 55 °C Run 2
mm®®®^
•~~*
0 240 480 720 960 1200
Normalized time (min)
Figure 10. Breakthrough and desorption curves of the IONEX 03-001 carbon at 55 °C/dry.
Desorption phase starts at the transition from solid to open symbols.
The performance of the IONEX 03-001 carbon at 25 °C/dry (Run 2 only) and 55 °C/dry
(Run 1 only) is compared in Figure 11. Significantly better adsorption performance was
demonstrated for the carbon bed tested at 55 °C/dry. The observation contradicts the
expectation, because for physisorption like GB, the adsorption capacity is expected to reduce
with increasing temperature. One factor that might contribute to the result is that the carbon beds
were pre-conditioned overnight at 25 °C/dry or 55°C/dry prior to testing. Prolonged pre-
conditioning (>16 h) at 55 °C/dry might desorb more contaminants or water vapor from the
carbon pores which enhances the carbon adsorption capacity. According to the carbon bed water
equilibrium tests conducted (see Appendix A), the carbon bed lost approximately 4 % of the
weight at 55 °C/dry versus 3 % of the weight at 25 °C/dry when pre-conditioned for 3 h.
29
-------
c
40 -,
i "
g 30-
I .
1 2°~
0 -
DO
CD 10-
•4— I
I •
B n
0-
C
Normalized time (h)
) 4 8 12 16 20
i
J
)
n
' n
' n
•
n
: V
\
- n 25 °C Run 2
• o 55°CRun1
mmmm ^i^^^C™"™™
600 12
00
Normalized time (min)
Figure 11. A comparison of the IONEX 03-001 carbon performance at 25 °C/dry and 55
°C/dry. Desorption phase starts at the transition from solid to open symbols.
4.3.3 Vapure 612 Carbon Tests
Four tests were conducted with the Vapure 612 carbon at a bed depth of 3.5 cm.
Duplicate tests were conducted at 25 °C/dry and 55 °C/dry conditions and a target challenge
concentration of 1,500 mg/m3. The GB challenge concentrations measured in the tests are
presented in Appendix C (Figures C-l 1 to C-16). Steady challenge concentrations were
achieved for the tests, with standard deviations less than 10 % of the averages.
The flow rate, temperature, and RH were steady throughout three of the four tests with
the Vapure 612 carbon (as shown in Figures C-l 1, C-l3, and C-l5). The exception was Run 2
with the Vapure 612 carbon at 25 °C/dry conditions. As shown in Figure C-12, the flow rate and
temperature were steady during the test, while RH spiked from <1 to 9.5 % at about 2 min after
switching from adsorption to desorption mode. The RH spike lasted approximately 18 min and
was due to an operation error when the air supply from the humidifier was interrupted. The flow
through the carbon bed during the incident was maintained at 9 Lpm (Figure C-12), with the air
pulled through the vent line to the carbon bed. Because the incident period was short (<20 min),
30
-------
the target flow rate of 9 L/min was maintained, and the spiked RH (i.e., <9.5 %) was still within
the range of the target RH for the dry condition (i.e., RH <15 %, as defined in Table 3); the
impact of the incident on the measurement of the desorption curve was believed to be negligible.
Pressure drop across the carbon bed was not recorded during the two tests at 25 °C/dry
conditions because the pressure transducer was not operating properly. Pressure drop was stable
during the tests at 55 °C/dry conditions. As shown in Figures C-14 and C-16, the average
pressure drop was approximately 0.14 inches of water with standard deviation less than 1.5 % of
the average. Lower pressure drop (-0.14 inches of water) was measured across a Vapure 612
carbon bed (3.5 cm) than across an IONEX 03-001 carbon bed (-0.23 inches of H2O). This
result is expected, considering the larger carbon particle size of the Vapure 612 carbon: 6x12
mesh for the Vapure 612 versus 8x12 mesh for the IONEX 03-001 carbon.
Measured breakthrough and desorption curves of the Vapure 612 carbon at 25 °C/dry
conditions are presented in Figure 12. As shown in Figure 12, the duplicate tests provided
rationally consistent results. Immediate breakthrough was measured with the Vapure 612 carbon
beds, which is similar to the tests with the ASZM-TEDA carbon. The effluent concentrations
increased from 0.2 mg/m3 at t = 0 min to 3.5 to 6.5 mg/m3 at the end of the adsorption test (i.e.,
350 min). Desorption concentrations decreased quickly at the initial stage and then leveled off.
After ten hours of desorption, the effluent concentration was approximately 0.4 to 0.7 mg/m3.
31
-------
Normalized time (h)
4 8 12
240 480 720 960
Normalized time (min)
1200
Figure 12. Breakthrough and desorption curves of the Vapure 612 carbon at 25 °C/dry.
Desorption phase starts at the transition from solid to open symbols.
Figure 13 presents the breakthrough and desorption curves of the Vapure 612 carbon at
55 °C/dry conditions. Immediate breakthrough occurred under these conditions, and the effluent
concentration increased steadily during the adsorption period. For example, during the first run,
the effluent concentrations increased to 5.8 mg/m3 at the end of adsorption (i.e., 270 min).
Desorption concentration decreased quickly at the initial stage and then increased gradually for
both runs. After ten h of desorption, the desorption concentration was 3.6 mg/m3 during Run 1
and approximately 4.5 mg/m3 during Run 2.
32
-------
c
8-,
CO ' ""
E .
| 5-
|4-
o 3-
DQ '
0 2-
•4— I
1 1-
c
Normalized time (h)
) 4 8 12 16 20
• D
n
• n
• ctg
f g
• 1
. ;
JL
tPn^gSM
o 55 °C Run 1
°_ 55 °C Run 2
^Hflfi
MBS*P*&
n n
itt n
Ki5U»-
) 240 480 720 960 1200
Normalized time (min)
Figure 13. Breakthrough and desorption curves of the Vapure 612 carbon at 55 °C/dry.
Desorption phase starts at the transition from solid to open symbols.
Only small quantities of the adsorbed GB were desorbed, which was consistent with the
tests using the ASZM-TEDA carbon and IONEX 03-001 carbon. For example, only 0.1 % and
0.5 % of the adsorbed GB was estimated to be desorbed after over 10 h of desorption for the tests
at 25°C/dry (Run 1) and 55 °C/dry (Run 1) conditions, respectively.
The performance of the Vapure 612 carbon at conditions of 25 °C/dry and 55 °C/dry is
compared in Figure 14. As shown in Figure 14, at the initial stage, the adsorption performance at
55 °C/dry was slightly better than the adsorption performance measured at 25 °C/dry, with lower
effluent concentration at 55 °C/dry until t = 100 and 30 min, respectively, for Run 1 and Run 2.
The breakthrough curves at 55 °C/dry condition then shifted to the left of the curves at 25 °C/dry
and behaved as expected at higher temperature. Initial better performance observed at 55 °C/dry
was consistent with the performance observed in the IONEX 03-001 carbon tests. According to
the carbon bed water equilibrium tests conducted (see Appendix A), the Vapure 612 carbon bed
lost approximately 4.2 % of the weight at 55 °C/dry versus 3.6 % at 25 °C/dry when pre-
conditioned for 3 h. Prolonged pre-conditioning at 55 °C/dry might be a factor contributing to
the results by desorbing more contaminants or water vapor out of the carbon pores.
33
-------
Desorption trends at 25 °C/dry and 55 °C/dry were also different. After passing the
initial desorption stage, the desorption concentration slowly decreased at 25 °C/dry, while
constantly increasing at 55 °C/dry.
Figure 14.
55 °C/dry.
Normalized time (h)
0 4 8 12 16 20
Q
Effluent GB Concentration (mg/m3)
D-^hOGOJ^OiOT^JC
•
t>
•0
Q
• o
• 0
• Qft
• ,
• 1
• /
1 1/
Jr
4?
•
•
• •
• • D
fO *
*T
^ n°
;
/ !%*•
f r °
f an
M D
f Dft
/^
X
° 25°CRuns1&2
• o 55°CRuns1&2
„ ^a^fSS^Sffifi
^^m^
Btlmittmt«mmmni
c
-iJ&rOSfS^
^P©
sassss^^
p
^^#
0 240 480 720 960 1200
Normalized time (min)
A comparison of the Vapure 612 carbon performance at 25 °C/dry an
Desorption phase starts at the transition from solid to open symbols.
4.3.4 ASZM-TEDA (12 x 30 Mesh) Carbon Tests
Two tests were conducted with the ASZM-TEDA (12 x 30 mesh) carbon: one trial each
at 25 °C/dry and 55 °C/dry conditions, both at a target challenge concentration of 1,500 mg/m3.
These tests were performed using a 2.5 cm bed depth and used the infusion vapor generation
method (described in Section 2.2.4.2) to generate the GB vapor challenge. Graphs depicting the
adsorption and desorption behavior under each test condition are shown in Figures 15 and 16.
Graphs summarizing the environmental conditions for each test are given in Appendix C
(Figures C-17 and CIS for ambient/dry conditions and Figures C-19 and C-20 for the hot/dry
conditions).
In Figure 15, the adsorption and desorption behavior of the ASZM-TEDA (12 x 30 mesh)
carbon at 25 °C/dry conditions is shown, overlaid with the measured challenge concentration.
34
-------
After confirming the challenge concentration at the target value (pre-test values were
approximately 1580 mg/m3), the challenge flow was switched through the test cell. The
measured GB challenge concentration was observed to drop to near 200 mg/m3 upon
introduction into the carbon bed. The measured challenge never returned to pre-test values.
Nevertheless, breakthrough of GB was detected within 100 to 120 minutes. The indicated drop
in challenge concentration was likely due to a leak in the system, though a leak was never
confirmed during testing. The plot of the pressure drop (Appendix C, Figure C-18) indicates a
gradual increase in upper cell pressure drop from 0.15 in H2O to 0.25 in H2O during the agent
exposure test. (Subsequent testing with the ASZM-TEDA (12 x 30 mesh) carbon with HD
showed that 0.25 in H^O was typical for this carbon type.) If there were imperfections in the
packed test bed allowing channeling of the challenge vapor, this channeling would have been
accompanied by an immediate challenge breakthrough observed in the effluent. This type of
breakthrough did not occur, as the effluent concentration remained at a baseline level (near the
detection limit) throughout the initial phase of the test. During the vapor infusion period, the
total volume of GB delivered during the challenge period was 2.2 mL, and this total volume is
consistent with the calculations for agent vapor generated at ca. 1500 mg/m3. The challenge
exposure was stopped at 143 min.
35
-------
time (h)
0 4 8 12 16 20
nn/in
Effluent GB Concentration (mg/m3)
ppppppppc
§oooooooc
O ->•->• K3 K3 CO CO
aiooiooiooic
1
-
•
B
ft
a
a
B
1 ^ %
J
, /
^
^AA
?;
L-/
Challengel
• n Effluent |
ifc§§lp^jjj
HSS^a
SBBftj^l^i
• i • i • i • i
GB Challenge Concentration (mg/m3)
) 240 480 720 960 1200
time (min)
Figure 15. Summary graph of ASZM-TEDA (12 x 30 mesh) carbon challenged with GB
vapor at 25 °C /dry conditions. Desorption phase starts at the transition from solid to open
symbols.
At the conclusion of the adsorption period, clean air was introduced through the test bed
and desorption phase was started. The desorption curve, shown in Figure 15, indicates that GB
desorption persisted throughout desorption period at a concentration of approximately one half of
the peak effluent concentration when the GB challenge was stopped at 143 min.
Figure 16 shows the adsorption and desorption behavior of GB at 55 °C/dry conditions on
the ASZM-TEDA (12 x 30 mesh) carbon at a 2.5 cm bed depth. The MINICAMS® effluent data
are overlaid with the challenge concentration data points. After an initial spike in the challenge
concentration, the GB vapor settled to near the target of 1500 mg/m3 (average = 1496 ± 256
mg/m3). Pre-testing system checks had ensured all connections in the vapor generation and
sampling lines were tightened. Environmental data for this test are shown in Appendix C,
Figures C-19 and C-20. Temperature and RH (Figure C-19) were stable throughout testing. The
pressure drop measurement (shown in Figure C-20) was also stable at approximately 0.26 in F^O
throughout the test. Challenge breakthrough was beginning to occur after approximately 100
min in the adsorption phase. After concluding the challenge exposure at 149 min, the desorption
36
-------
curve was monitored overnight. The desorption phase also displayed the persistent off-gassing
of GB (dropping from 0.85 mg/m3 to 0.40 mg/rr
in the ambient test using this same carbon type.
of GB (dropping from 0.85 mg/m3 to 0.40 mg/m3 during the overnight desorption test) observed
0
Normalized time (h)
4 8 12 16
0 240 480 720 960 1200
Normalized time (min)
Figure 16. Summary graph of ASZM-TEDA (12 x 30 mesh) carbon challenged with GB
vapor at 55 °C/dry conditions. Desorption phase starts at the transition from solid to open
symbols.
The performance of the ASZM-TEDA (12 x 30 mesh) carbon at conditions of 25 °C/dry
and 55 °C/dry is compared in Figure 17. As shown in Figure 17, with a focus on the first six
hours of the test, significantly better adsorption performance was demonstrated for the carbon
bed tested at 25 °C/dry. This behavior is in line with the expectation that a higher temperature
leads to reduced adsorption capacity. Desorption trends were similar. After passing the initial
fast desorption stage, the desorption concentration slowly decreased for both temperatures at
approximately the same rate.
37
-------
C
^ 0.8-
"1 -
it GB Concentration (rr
o o o
Ko j^ b)
S .
E
C
time (h)
) 1 2 3 4 5 6
)~' 60
.
•
•
120
*0
C
"^^p
****,
^
• n 25°C
• ° 55°C
180 240 300 360
420 4*
30
time (min)
Figure 17. Summary graph of ASZM-TEDA (12 x 30 mesh) carbon challenged with GB
vapor at 55 °C/dry conditions. Desorption phase starts at the transition from solid to open
symbols.
4.3.5. High Humidity Adsorption and Desorption Studies
The initial test plan called for additional tests for all carbons at high temperature and high
humidity (55 °C/50 % T/RH values). HF was detected in the effluent of a preliminary test at this
55 °C/50 % RH condition. Consequently, adsorption tests originally planned under this
condition were not executed for any of the carbon beds. HF is highly corrosive, and its presence
posed a serious hazard to the analysis equipment in this study. At high temperature and humidity,
FTP is believed to form as a GB decomposition/hydrolysis product. Although adsorption of FTP
onto activated carbon may be feasible, such investigation was beyond the scope of this study and
was not investigated further. Nevertheless, FTP formation due to hydrolysis of GB at elevated RH
would still pose a risk to, e.g., the duct work of an HVAC system through which the hot air is
transported. Using the aforementioned release scenario and assuming complete hydrolysis of
GB, the HF concentration could be as high as 260 parts per million (ppm). This concentration is
at the lower end of laboratory studies that investigate the impact of HF on (electronic)
38
-------
equipment. A further assessment of the impact, i.e., corrosion that HF may have on metal
ductwork was beyond the scope of this study.
4.4 Results for HD
HD adsorption and desorption tests were performed using the IONEX 03-001 carbon and
both ASZM-TEDA carbons at a bed depth of 2.5 cm. Single tests were conducted at 25°C/dry,
55 °C/dry and 55 °C/humid conditions with a target challenge concentration of 500 mg/m3. In
addition, a single test was performed using the ASZM-TEDA (6x16 mesh) carbon at 25 °C/dry
condition. The HD environmental conditions measured in the tests are presented in Appendix C
(Figures C-21 to C-27 for IONEX 03-001 [8 x 16 mesh], Figures C-28 to C-33 for ASZM-
TEDA [12 x 30 mesh], and Figures C-34 and C-35 for ASZM-TEDA [6 x 16 mesh]).
An HD shakedown test was completed with the IONEX 03-001 carbon using a 2.5 cm
bed depth at 25 °C/dry conditions and a target challenge concentration of 500 mg/m3. The test
confirmed that the target challenge could be achieved and maintained and that immediate
breakthrough did not occur using the 2.5 cm bed depth.
4.4.1 IONEX 03-001 (8 x 16 Mesh) Carbon Tests with HD
Three HD tests were conducted with the IONEX 03-001 carbon using a bed depth of 2.5
cm. Single tests were conducted at 25 °C/dry, 55 °C/dry, and 55°C/humid conditions and a
target challenge concentration of 500 mg/m3. The HD challenge concentrations measured in the
tests are overlaid with the MINICAMS® effluent results in subsequent graphs. Steady challenge
concentrations were generally achieved during the tests, though the generation system was
shown to be sensitive and produced unexpected changes in concentration. The test cell
temperature, RH and pressure drop across the test bed were monitored throughout the IONEX
03-001 carbon tests (as shown in Appendix C, Figures C-21 through C-21). The temperature and
RH were steady throughout testing.
The summary graph shown in Figure 18 depicts the challenge, adsorption and desorption
results of the IONEX 03-001 carbon at 25 °C/dry conditions. The HD challenge concentration,
shown in the upper left, averaged 547 mg/m3 over the duration of the challenge period (381 min).
39
-------
Once the desorption phase started, the HD effluent decreased at a rate comparable to the
adsorption curve. HD desorption returned to low baseline values (detection limit of the
MINICAMS®) after approximately 400 min desorption time. Figures C-21 and C-22 in
Appendix C show the temperature, humidity and pressure drop measurements made during the
duration of the adsorption and desorption at 25 °C/dry conditions. The graphs indicate that the
environmental conditions were stable throughout testing.
Normalized time (h)
0 4 8 12 16 20 24
06 vnn
*£ 0.5-
Effluent HD Concentration
D O O O C
D ->• Ko CO j:
A
J
i^
i
i
f n
I I
• I
inn
iiliii i
mil i i n
i mi inn
•
A Challenge 1 .
° Effluent| -
in in n i nn r
in n
-
U UULLLLJ LJJ Ul Illl 1 II ILIi
0 240 480 720 960 1200 14
Normalized time (min)
HD Challenge Concentration (mg/m3)
Figure 18. Summary graph of IONEX 03-001 carbon challenged with HD vapor at 25
°C/dry conditions. Desorption phase starts at the transition from solid to open symbols.
In Figure 19, the combined results of the adsorption and desorption testing of the IONEX
03-001 carbon at 55 °C/dry conditions are shown. During this test, the HD vapor challenge
started higher (approximately 700 mg/m3) than the target concentration, but ultimately was
brought into the target range after approximately 150 min of system troubleshooting (which
included shutting off the syringe pump feed to allow the system to clear to lower vapor
concentrations). The average HD vapor challenge concentration over the duration of adsorption
testing was 508 ± 170 mg/m3. The initial phase of the effluent curve during the adsorption test
corresponded to the fluctuations observed while attempting to troubleshoot the challenge
40
-------
generation. The effluent HD data in Figure 19 were not corrected for the fluctuations in the
vapor challenge. A numerical approach to adjust the adsorption time using the actual vapor
challenge concentration profile (as opposed to a correction based on the mean of the vapor
challenge concentrations across the adsorption phase) shows that the impact of the irregular
delivery is very minimal with the last data point prior to the end of the adsorption phase shifting
to a shorter time by only 8 minutes. After observing breakthrough behavior in the adsorption
curve, the HD challenge vapor was stopped after 390 min, and the system was placed in
desorption mode. The HD effluent vapor concentration dropped to near baseline levels after
approximately 100 min.
Normalized time (h)
0 4 8 12 16 20 24
06 Qnn
W. w
CO -, ,-
E 0.5-
^ 0.4-
.0
1 °'3-
g
0 0.2-
Q
1 01-
^u
^ 00
u.u-
c
*>A
A
A
J
• r
• o
*£4
1
j c
•
^ c
/ o
?-v
^
) 2^
\*
V*^mm^
10 4J
•
A Challenge 1 '
• o Effluentl"
•
-
-
-
•
-
30 720 960 1200 14
V^Vi/V./
700^
600 ?
g
500 -^
400 §
300 0
CD
O)
200 g
78
100 g
Q
0~r
-1-
40
Normalized time (min)
Figure 19. Summary graph of IONEX 03-001 carbon challenged with HD vapor at 55
°C/dry conditions. Desorption phase starts at the transition from solid to open symbols.
The environmental conditions for this challenge at 55 °C/dry conditions are shown in
Figures C-23 and C-24 in Appendix C. The temperature and RH for the test (Figure C-23) were
steady throughout the testing period just like the measured pressure drop (Figure C-24),
indicating stable flow conditions.
41
-------
A comparison of the 25 °C/dry and 55 °C/dry adsorption/desorption curve results is
shown in Figure 20. Both sets of data were obtained using FID detection. The adsorption
performance of this carbon is similar between the two test conditions, while a slight difference in
the desorption behavior is noted between the two test conditions. The desorption in the 25
°C/dry test occurred less rapidly than the 55 °C/dry desorption over the first five hours of the
desorption period.
Normalized time (h)
0 4 8 12 16 20 24
06
"? 0.5-
^ 0.4-
Effluent HD Concentratio
D O O O
D ->• Ko CO
•
•f)
/I 0
/ '
inn
Him i
iiiiiii i i n
i mi inn
"^u^S
inn
- 25°C-dry
• ° 55°C-dry
in
' V...V..:.. " "UMIJIMUUIIL,^
0 240 480 720 960 1200 1440
Normalized time (min)
Figure 20. Summary of HD adsorption and desorption for IONEX 03-001 carbon at 25
°C/dry and 55 °C/dry conditions. Desorption phase starts at the transition from solid to
open symbols.
The graphical summary of the IONEX 03-001 carbon at 55 °C/humid conditions is shown
in Figure 21. Environmental conditions (temperature and humidity) for this test are shown in
Appendix C (Figures C-25 and C-26). The humidity target for this test was 50 %. The RH plot
in Figure C-25 showed that the humidity dropped to an average of 35 % upon addition of the HD
vapor to the challenge air stream and displayed large variations throughout testing under these
conditions. This drop in humidity could not be compensated, despite repeated attempts to adjust
air flow and humidity bath temperatures during the test. The plot of pressure drop in Figure
42
-------
C-26 shows a decreasing trend in pressure drop across the test bed during adsorption testing from
0.15 in H2O to 0.075 in H^O (plot shows both the upper and lower bed pressure readings, relative
to ambient pressure). In addition, condensation formed in the downstream sampling line
(MINICAMS®) after a period of time, causing the MINICAMS® MFC to fail after 258 min.
This behavior is observed in the MINICAMS flow vs. time plot, shown in Appendix C, Figure
C-27. The formation of condensation was caused by temperature gradients in the sampling
system. Dew point calculations suggested that the entire test system should be above 41 °C to
prevent condensation. While the test cell was conditioned to 55 °C and the sample line prior to
the MINICAMS® was heated, and the MINICAMS® itself has heated zones that pertain to
chromatography, the MINICAMS® sampling MFC and post-instrument exhaust lines were not
heated (and, in the case of the MFC, should not be). Prior to this flow issue, the MINICAMS
did not indicate evidence of HD breakthrough. Both the FID and FPD detectors were monitored
during this test to ensure possible detection of effluent breakthrough. The average HD vapor
challenge concentration was 482 ± 98 mg/m3 for the duration of the adsorption test. At 350 min,
the adsorption test was halted (due to the MINICAMS® sampling malfunction). The desorption
phase could not be completed due to lack of response by the MINICAMS®. To verify an ending
effluent concentration for the adsorption phase of testing, two SSTs were acquired downstream
of the carbon bed at t = 350 min, extracted with acetone, and analyzed for HD using GC-FID.
The resulting concentration was ~ 0.04 mg/m3 HD, a low concentration typical of pre-
breakthrough "baseline" behavior (the detection limit, based on previous testing).
43
-------
0.6
l>0.5-
o 0.4-
§0.3-
<§ '
00.2-
0
time (h)
8
12
E
n 4
U.I
0.0
A
V *A*
A
.
•
t
\ .
V. V
^•^NV.
A
•
* Challenge 1
• Effluent (FID) | .
A A
A A
A
*
B
J
*• <•_•
'
-
;
•
.
.
uuu
-71-11-1 ^
700 0)
600 ^
500 2
400 |
8
300
-------
likely to condense than be vaporized. After performing maintenance on the system at the
conclusion of HD testing, a soft, polymeric material was collected from the agent injection inlet
on the heated transfer line. This material was analyzed and determined to contain TDG.
4.4.2 ASZM-TEDA (12 x 30 Mesh) Carbon Tests with HD
A graphic summary of the ASZM-TEDA (12 x 30 mesh) carbon, exposed to HD at
25 °C and dry conditions, is given in Figure 22. The plot shows the challenge HD concentration
(average of 576 ± 180 mg/m3), along with both the FID and FPD MINICAMS® data, showing
the effluent HD concentration. Responses from both MINICAMS® detectors were
undistinguishable at this low concentration. Environmental conditions are given in Appendix C,
Figures C-28 and C-29. The test bed was challenged for 355 min, during which no evidence of
breakthrough was observed in the effluent data. Some instability was noted in the challenge
concentration, where the concentration increased to saturation levels during the final 100 min of
exposure. This instability did not impact the effluent breakthrough curve. After the agent
exposure period, the test bed was exposed to clean air overnight, during which no evidence of
desorption was observed. Changes observed in the MINICAMS plot were all below the
detection limit and are considered noise.
45
-------
time (h)
0 4 8 12 16 20 24
0 10 /innn
w. I \J H
-------
A graphical summary of the ASZM-TEDA (12 x 30 mesh) carbon, exposed to HD at
55 °C and dry conditions, is shown in Figure 24. The plot shows the challenge HD concentration
(average of 527 ± 60 mg/m3), along with both the FID and FPD MINICAMS® data, showing the
effluent HD concentration. Responses from both MINICAMS® detectors were undistinguishable
at this low concentration. Graphs showing the environmental conditions are given in Appendix
C, Figures C-30 and C-31. The test bed was challenged for 346 minutes, during which no
evidence of breakthrough was observed in the effluent data. After the agent exposure period, the
test bed was exposed to non-agent laden air overnight, during which no evidence of desorption
was observed.
time (h)
0 2 4 6 8 10 12 14 1
0 10
"f
I 0.08-
1\ "
Effluent HD Concentrati
D O O C
B 8 8 S
i.i.i
>*
•• •«
"V
* •
^
> • •
•
* Challenge 1
• o Effluent |
c
-
0 120 240 360 480 600 720 840 9(
time (min)
o ^
HD Challenge Concentration (mg/m3)
Figure 24. Summary graph of ASZM-TEDA (12 x 30 mesh) carbon challenged with HD
vapor at 55 °C/dry conditions. Desorption phase starts at the transition from solid to open
symbols.
A summary graph of the ASZM-TEDA (12 x 30 mesh) carbon adsorption and desorption
curves, after exposure to HD vapor at 55 °C and humid conditions, is shown in Figure 25. After
completing the IONEX 03-001 test at 55 °C/50 % RH, the humidity in this test (20 %) was
chosen on the basis of the potential for dew point condensation at room temperature that caused
the MINICAMS® MFC to fail. Environmental conditions are shown in Appendix C, Figures C-
47
-------
32 and C-33. The plot in Figure 25 shows the average HD vapor challenge concentration (514 ±
24 mg/m3), along with both the FID and FPD MINICAMS® data, showing the effluent HD
concentration. The test bed was challenged for 366 min, during which no evidence of
breakthrough was observed in the effluent data. After the agent exposure period, the test bed
was exposed to clean air overnight, during which no evidence of desorption was observed.
Despite the lower humidity, problems with condensation still occurred during the overnight
desorption test, resulting in the MINICAMS sampling MFC failure after 300 min of desorption
time (Appendix C, Figure C-34). Observed peaks in the effluent as observed by MINICAMS® in
FID mode after 480 minutes are presumably due to condensation and injection of water into
system. These responses do not reflect actual breakthrough of agent.
048
040
(O
E 0.35-
?030-
g
'I 0.25-
§ 0.20;
c *
<3oi5-
Q
I „ '
— 0.10-
-------
the test was completed and found to contain both HD and TDG. TDG was also found at the
injection point of the agent vapor infusion system while performing system maintenance at the
conclusion of HD testing. The temperature of the generation system was not high enough to
induce bulk TDG vaporization (thus, the material must have collected at the injection point as it
formed over a period of time). In addition, continued decomposition of HD to TDG while HD
was adsorbed to the carbon bed is not an unreasonable decomposition route under these test
conditions.
4.4.3 ASZM-TEDA (6 x 16 Mesh) Carbon Test with HD
As a single point of comparison to confirm the effects of ASZM-TEDA carbon particle
mesh size on adsorption behavior (relevant in comparison to the 12 x 30 mesh carbon
performance), the ASZM-TEDA (6^16 mesh) carbon was tested against an HD vapor challenge
under ambient conditions using a 2.5 cm bed depth. A graphical summary of the ASZM-TEDA
(6x16 mesh) carbon exposed to HD at 25 °C and dry conditions is shown in Figure 26. The plot
shows the average HD vapor challenge concentration (534 ± 70 mg/m3), along with the FID
MINICAMS data, showing the effluent HD concentration. Environmental data from this test
are shown in Appendix C, Figure C-35 and C-36. The test bed was challenged for 337 min, and
evidence of breakthrough was notable during this test. Some instability was noted in the
challenge concentration, where the concentration increased to nearly 600 mg/m3 after 150 min of
testing. This increase in the challenge concentration appears to correlate with a sudden increase
in the effluent concentration. After the agent exposure period, the test bed was exposed to clean
air overnight, resulting in rapid desorption as observed in previous GB testing using this carbon.
49
-------
Normalized time (h)
0 4 8 12 16 20 24
50 /innn
\J. W T
^ 4.5-
"c
"1) 4.0-
O « «
S 3-°~
8 zo"
Q 1.5-
I
-£ 1.0-
Q)
^ 0.5-
s
00-
•
•
•
•
X-f*
^T;
n
^ /
V
s
r
\
\
^
A Challenge 1
• o Effluent | '
^^
^s^^g
*%^
^^
Stefi^ra*™,
-
•
.
-
.
1 ~~™*™*msi™pIKaM«MM
1 \J\J\J
CO
E
800 o)
o
600 '"g
400 o
CD
S
200 =
^
O
Q
n m
0 240 480 720 960 1200 1440
Normalized time (min)
Figure 26. Summary graph of ASZM-TEDA (6 x 16 mesh) carbon challenged with HD
vapor at 25 °C/dry conditions. Desorption phase starts at the transition from solid to open
symbols.
50
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5.0 SUMMARY
5.1 Sarin, GB
Four types of activated carbons (ASZM-TEDA [6 x 16 mesh and 12 x 30 mesh], IONEX
03-001 [8 x 16 mesh], and Vapure 612 [6 x 12 mesh]) were tested against a GB vapor challenge
for adsorption and desorption performance. The target test challenge concentration was 1,500
mg/m3 of GB. The ASZM-TEDA (6 x 16 mesh) carbon was tested at 25 °C/dry conditions at
three carbon bed depths of 2.5, 3.0, and 3.5 cm. The IONEX 03-001 and Vapure 612 carbons
were tested at a carbon bed depth of 3.5 cm and two temperature/RH conditions (25 °C/dry and
55 °C/dry). Lastly, the ASZM-TEDA (12 x 30 mesh) was tested at a carbon bed depth of 2.5 cm
and two temperature/RH conditions (25 °C/dry and 55 °C/dry). A total of 14 GB adsorption and
desorption tests were performed.
Among the coarser carbons tested (i.e., excluding the ASZM-TEDA (12 x 30 mesh)
carbon results), the IONEX 03-001 carbon demonstrated the best GB adsorption performance,
with carbon bed effluent concentration held at <0.04 mg/m3 for 85 and 170 min, respectively, at
25 °C/dry and 55 °C/dry conditions for a 3.5 cm bed depth. Immediate breakthrough occurred
with both the ASZM-TEDA (6x16 mesh) and Vapure 612 carbon beds, as the GB concentration
in the effluent steadily increased, albeit initially very gradually. Comparable adsorption curves
were obtained for the GB vapor on the ASZM-TEDA (12 x 30 mesh) carbon bed relative to the
IONEX 03-001 carbon, and the effluent concentration was held at < 0.04 mg/m3 for 100 min at
55 °C/dry conditions. The thinner 2.5 cm carbon bed depth was specified for this carbon due to a
primary focus on HD testing at the time of the last two GB tests. Initial estimates for HD vapor
breakthrough (see Section 4.5) indicated longer breakthrough times for most carbons than
observed for GB vapor, hence a shorter bed depth was used. Increasing temperature from 25 °C
to 55 °C (at dry RH) shifted the onset of GB adsorption slightly to shorter times, e.g., better
adsorption performance measured for the ASZM-TEDA (12 x 30 mesh) in the initial stage of
adsorption under 25 °C/dry test conditions (< 0.04 mg/m3 for 140 min at 25 °C/dry conditions).
Contrary to anticipated results, increasing temperature from 25 °C/dry to 55 °C/dry did
not appear to affect the carbon bed adsorption performance adversely, with significantly better
51
-------
adsorption performance measured for the IONEX 03-001 carbon and better adsorption
performance observed for the Vapure 612 carbon at the initial stage of adsorption. There is no
definitive explanation for this result. Prolonged (>16 h) pre-conditioning at 55 °C/dry was
believed to be a factor, since the pre-conditioning might desorb contaminants or water vapor
from carbon pores to increase the adsorption capacity (pre-conditioning the IONEX 03-001 and
Vapure 612 carbon at 55 °C/dry conditions yielded 4 and 4.6 % weight loss, respectively).
The breakthrough curve measurements were used to calculate the dynamic adsorption
capacity of each of the tested carbons for GB at various temperatures. These values were based
on the measured carbon mass (see Appendix C) from which the carbon density was derived for
the tested carbons except for the ASZM-TEDA (12 x 30 mesh) carbon density for which a
literature value was used. To obtain comparable results across all carbons, the breakthrough time
was defined here as the time to reach the immediately dangerous to life or health (IDLH)
concentration (0.1 mg/m3 for GB [NIOSH 2013]) in the effluent. Note that under real conditions,
the effluent should not be allowed to reach this concentration unless that effluent is captured in a
second carbon bed of equal or larger/thicker size. Table 4 summarizes the calculated dynamic
adsorption capacity. Values for the ASZM-TEDA (6x16 mesh) and Vapure 612 carbon are
upper values because breakthrough as defined here occurred nearly immediately following
exposure of the carbon to the 1500 mg/m3 GB challenge concentration.
Table 4. Dynamic desorption capacities for GB of tested carbons based on 3.5 cm bed
depth measurements.
Dynamic Desorption Capacity
Carbon Type Mesh Size (g GB/g carbon)
25 °C 55 °C
Calgon Carbon ASZM-TEDA™
Calgon Carbon ASZM-TEDA™
IONEX Research IONEX 03-001
Cabot Norit® Vapure™ 612
6 x 16
12 x 30
8 x 16
6 x 12
0.006
0.095
0.076a
0.004
NA
0.081
0.148b
0.004
NA: Not Attempted
a: Run #2
b:Run#l
52
-------
GB desorption from the carbon bed was observed for all three types of carbons, after the
GB challenge was stopped and clean air was pulled through the carbon bed at the flow and T/RH
conditions equivalent to the adsorption test. In general, the GB concentration downstream of the
carbon bed, as a result of GB desorbing from the carbon, decreased quickly at the initial stage of
desorption, and then leveled off. The desorption behavior was dependent on temperature. After
an initial drop in GB concentration downstream of the carbon (effluent stream), the GB
concentration continued to decrease with time as 25 °C dry clean air continued to flow through
the carbon bed. Conversely, after an initial decrease in GB concentration, the GB concentration
in the effluent gradually increased with time as 55 °C, dry, clean air continued to flow through
the carbon bed. Consequently, GB desorption may pose more risk at the higher temperature of
55 °C because of the slowly increasing trend of the desorption concentration with time.
GB desorption from the carbon beds was persistent for each of the carbons tested, with
desorption concentrations sustained at levels of three to four order of magnitude higher than the
STEL (i.e., 0.0001 mg/m3 for GB) after ten hours of desorption. Only a small quantity of the
adsorbed GB, however, was desorbed. After desorption for up to ten hours, less than 1 % of the
adsorbed GB was desorbed at both 25 °C/dry and 55 °C/dry conditions for all types of carbons
tested.
GB adsorption at high temperature (55 °C) and high humidity (-50 %) was not performed
due to the observation of HF in a preliminary test at this condition. HF is highly corrosive and is
believed to form as a GB decomposition/hydrolysis product. Such tests were not run due to the
potential damage to analytical equipment.
5.2 Sulfur Mustard, HD
Three types of activated carbon (ASZM-TEDA [6 x 16 mesh], ASZM-TEDA [12 x 30
mesh], and IONEX 03-001 [8 x 16 mesh]) were tested successfully against an HD vapor
challenge for adsorption and desorption performance. The target test challenge concentration
was 500 mg/m3 for HD. The three carbons used in HD testing were tested at 25 °C/dry, 55
°C/dry, and 55 °C/humid conditions. A total of seven HD adsorption and desorption tests were
performed.
53
-------
In the HD vapor challenge tests, the ASZM-TEDA (12 x 30 mesh) carbon out-performed
the IONEX 03-001 carbon. No evidence of breakthrough was observed after nearly six h of HD
vapor exposure under all test conditions using the ASZM-TEDA (12 x 30 mesh) carbon. The
IONEX 03-001 carbon began exhibiting breakthrough behavior at approximately three to four h
of HD vapor exposure. Comparison of the ASZM-TEDA (12 x 30 mesh) carbon test result to
the ASZM-TEDA (6^16 mesh) carbon test result under the 25 °C/dry conditions indicates that
the difference in granule size is the primary reason for this difference in breakthrough behavior.
Such a result is consistent with adsorption theory. The larger mesh (smaller granule sizes)
enhances mass transfer and can adsorb the incoming vapor much more rapidly. Similar to the
observation made in GB testing, increasing the test temperature from 25 °C to 55 °C did not
appear to impact the adsorption behavior of the IONEX 03-001 carbon towards HD vapor
significantly. The lack of replicates for each test condition does not allow to conduct a more
statistical evaluation to determine whether this observation is (statistically) significant.
Like the GB data, the breakthrough curve measurements were used to calculate the
dynamic adsorption capacity of each of the tested carbons for HD. As before, the breakthrough
time was defined here as the time to reach the IDLH concentration (0.7 mg/m3 for HD, [NIOSH
2013]) in the effluent. Table 5 summarizes the calculated dynamic adsorption capacity. Values
for the ASZM-TEDA (12^30 mesh) represent low estimates as no breakthroughs were observed
for this carbon when exposed to the 500 mg/m3 HD challenge concentration.
Table 5. Dynamic desorption capacities for HD of tested carbons based on 2.5 cm bed
depth measurements under dry (< 15% RH) conditions.
Carbon Type
IONEX Research
IONEX 03-001
Calgon Carbon
ASZM-TEDA™
Calgon Carbon
ASZM-TEDA™
Dynamic Desorption Capacity
Mesh Size (g HD/g carbon)
25 °C 55 °C
8 x 16
12 x30
6x 16
0.148
> 0.090
0.010
0.137
> 0.080
NA
NA: Not Attempted
Desorption of HD from the IONEX 03-001 carbon was more rapid at 55 °C compared to
the 25 °C test condition. Testing HD vapor adsorption and desorption at 55 °C/humid conditions
was complicated by condensation in the MINICAMS® sample flow system. For the IONEX 03-
54
-------
001 carbon, sorbent tubes collected at the conclusion of the challenge period (350 min)
confirmed a low concentration (-0.04 mg/m3) of HD. Analysis of post-challenge sorbent tubes
indicated the presence of TDG in the effluent. Continued decomposition of HD to TDG while
adsorbed to the carbon bed is not an unreasonable decomposition route under these test
conditions.
55
-------
6.0 GENERAL CONCLUSIONS
Consideration of both the adsorption and desorption characteristics of a carbon under
different environmental conditions should be critical to the choice of carbon in filtration systems.
Table 6 summarizes the trends in breakthrough times when compared to the 25 °C/dry
breakthrough time of the same carbon. Different CWAs appear to behave differently on the
carbon beds as shown here for GB and HD. GB adsorbs well to the IONEX 03-001 carbon but
also significantly desorbs from the carbon, particularly under high temperatures. The ASZM-
TEDA (12x30 mesh) carbon performed comparably with regard to both adsorption and
desorption characteristics (although differences in bed depth preclude a direct comparison with
the IONEX 03-001 carbon). Further, HF formation from the degradation of GB under humid
conditions is a significant concern for human safety and infrastructure integrity. FID adsorbs
best to the ASZM-TEDA (12 x 30 mesh) carbon, with no evidence of breakthrough up to six h of
exposure to 500 mg/m3 of HD. Decomposition of HD is also evident on both the IONEX 03-001
carbon and the ASZM-TEDA (12 x 30 mesh) carbon under humid conditions, but the
decomposition product (TDG) does not appear to pose a significant threat to infrastructure
integrity or human safety.
Breakthrough time comparisons made in this report assume that the impacts of
temperature, bed thickness and RH are independent. Any interaction effects among these
parameters could not have been estimated in this study because of the lack of replicates for most
of the experimental test conditions. The inherent difficulty of using CWAs in large quantities
(milliliters of agent consumed per test) limits a more thorough research effort with sufficient
replicates.
This research provides information on the impact of temperature and RH on the
performance of activated carbon beds as to capture chemical warfare agent vapors. The observed
changes in breakthrough times for GB and HD at elevated temperatures and RH will provide
decision makers with information for the use of these activated carbon to capture the effluent air
flow. This information will facilitate their use as part of a hot air decontamination approach to
remediate an indoor facility.
56
-------
Table 6. Summary of trends in breakthrough times with respect to 25 °C adsorption
results.
Agent, concentration (mg/m3)
Carbon Type
Calgon Carbon
ASZM-TEDA™
Calgon Carbon
ASZM-TEDA™
IONEX Research
IONEX 03-001
Cabot Norit®
Vapure™ 612
Mesh Size
6 x 16
12 x 30
8 x 16
6 x 12
GB, 1500
55 °C/dry
ND
-
++
-
55 °C/humid
NAa
NAa
NDa
NAa
HD, 500
55 °C/dry
NA
+/-
=
NA
55 °C/humid
NA
+/-
++b
NA
++: longer breakthrough time
=: equal breakthrough time; no discernable impact
- -: shorter breakthrough times
+/-: no breakthrough observed for any condition
ND: Not Determined
NA: Not Attempted
aNot determined due to formation of HF.
b Enhanced HD hydrolysis extends breakthrough time.
57
-------
7.0 REFERENCES
ASTM Standard Guide for Gas-Phase Adsorption Testing of Activated Carbon, D5160-95
(Reapproved 2008).
Battelle SOP HMRC X-283, "Evaluation of the Activated Carbon Beds with Chemical Agent
Vapors". SOP available upon request; see Disclaimer.
Clark, D. N., "Review of Reactions of Chemical Agents in Water", AD-A213, Defense
Technical Information Center, September 1989.
EPA 2009 Report. Decontamination of Toxic Industrial Chemicals and Chemical Warfare
Agents on Building Materials Using Chlorine Dioxide Fumigant and Liquid Oxidant
Technologies.
U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/012, 2009
EPA 2010 Report. Assessment of Fumigants for Decontamination of Surfaces Contaminated
with Chemical Warfare Agents. U.S. Environmental Protection Agency, Research Triangle Park,
NC, EPA/600/R-10/035, 2010.
EPA 2011 Report. Decontamination of Sulfur Mustard and Thickened Sulfur Mustard Using
Chlorine Dioxide Fumigation. U.S. Environmental Protection Agency, Research Triangle Park,
NC, EPA/600/R-11/051, 2011.
McGarvey, D., Mahle, J., and Wagner, G. Chemical Agent Hydrolysis on Dry and Humidified
Adsorbents (No. ECBC-TR-334), Edgewood Chemical Biological Center, Aberdeen Proving
Ground, MD, 2003.
National Institute for Occupational Safety and Health (NIOSH) Education and Information
Division, http://www.cdc.gov/niosh/ershdb/AgentListCategory.html. Page last updated June 18,
2013. Last access May 2014.
58
-------
Wagner, G., Sorrick, D. C., Procell, L. R., Brickhouse, M. D., Mcvey, I. F., and Schwartz, L. I.
Decontamination of VX, GD, and HD on a Surface Using Modified Vaporized Hydrogen
Peroxide, Langmuir 2007, 23, 1178-1186.
59
-------
APPENDIX A: CARBON BED EQUILIBRIUM TESTS
A-l
-------
A.1 INTRODUCTION
Prior to the chemical agent adsorption/desorption testing, each carbon bed was
preconditioned to achieve equilibrium at the environmental conditions (i.e., temperature and
RH) to be used in the agent testing. Preconditioning was included to ensure that breakthrough
data were obtained with the carbon bed in the same state as the conditions under which the
agent was added. This approach avoids that breakthrough data were collected in which the
environmental conditions of the challenge air flow were changing the local carbon bed
temperature and RH until equilibrium would be reached
The preconditioning process was conducted by flowing air (at the target temperature and
relative humidity) through the carbon bed until water vapor adsorption equilibrium was
achieved. To determine the time required to achieve water vapor adsorption equilibrium, a set
of equilibrium tests was conducted at three test conditions of 55 ± 2 °C and 50 ± 5 % RH, 55 ±
2 °C and dry (<15 % RH) and 25 ± 2 °C and dry. Those results are presented in Section A.3.
The test system and approach to precondition the carbon is described briefly in Section
A.2. The test system described is the same system that is used to test the chemical warfare
agent adsorption characteristics of the carbon at the target environmental conditions.
A.2 TEST METHOD
During the water vapor equilibrium test, carbon was loaded into the carbon holder in the
same manner that was used for the agent adsorption tests. Three carbon types were selected: (1)
ASZM-TEDA carbon (6x16 mesh) from Calgon Carbon, (2) IONEX 03-001 (8x16 mesh)
from IONEX Research Corporation, and (3) Norit® Vapure™ 612 (6 x 12 mesh) from Cabot
Norit Activated Carbon. The carbon bed depth for each carbon was 2.5 cm with a 4.0 cm cross
section, corresponding to carbon weights of 20.6, 14.3, and 16.0 grams (g), respectively, for the
ASZM-TEDA (6x16 mesh) carbon, IONEX 03-001 carbon, and Vapure 612 carbon. The
filtered air stream flowing through the carbon bed was maintained at the target condition of
temperature (55 or 25 °C), RH (50 % or <15 %), and 9 L/min, corresponding to a face velocity of
12 cm/s (the same as the velocity required for the chemical agent adsorption test). Every hour,
the air flow was stopped; the carbon holder was disconnected from the test system and weighed.
A-2
-------
The carbon holder was then returned to the test system, and air flowed through the carbon bed
for another hour. This process was repeated until the carbon weight did not increase for two
consecutive measurements, or until ten h of preconditioning testing. If the carbon weight still
increased after ten h of testing, the preconditioning test was continued overnight without the
hourly weight measurement. The carbon weight was measured next morning after about 24 h of
the preconditioning.
A schematic of the test system is depicted in Figure A-l; details are described in the main
body of this report.
Vent
Regulator
Compressed
House Air
Figure A-l. Schematic of the test system used for carbon performance evaluation.
The flow rate through the carbon bed was controlled by a mass flow controller from
AALBORG Instruments and Control (Series No. GFC17; Orangeburg, NY, USA). The
temperature and RH in the system challenge were monitored continuously by a T-RH probe from
Vaisala (Model No. HMT338, Helsinki, Finland). Air stream temperatures at the top and bottom
of the carbon bed were monitored by two thermocouples. All temperature, relative humidity, and
flow rate data were recorded throughout the test by a data acquisition system from Yokogawa
(Houston, TX, USA). The relative humidity at the carbon bed was not measured. Instead, the
RH was calculated based on the RH and temperature measured in the system influent and the
A-3
-------
average temperature measured at the top and bottom of the carbon bed using the following
equations:
PSat
RHCarbon Bed
- Average _BetV (1)
where RHCarbon Bed is the relative humidity at the carbon bed, Tiniet is the temperature in the
system influent, TAverageBed is the average of the temperatures measured at the top and bottom
of the carbon bed, Psat(Tiniet) is the saturation water vapor pressure at Tiniet, RHiniet is the relative
humidity measured in system influent, and Psat(TAverage Bed) is the saturation water vapor
pressure at T Average Bed-
A.3 TEST RESULTS
A.3.1 Carbon Bed Equilibrium Time at 55 ± 2 °C and 50 ± 5 % RH
The measured plots of weight gain versus preconditioning time at 55 ± 2 °C and 50 ± 5 %
RH are presented in Figures A-2, A-3, and A-4, respectively, for the ASZM-TEDA (6 x 16
mesh), the IONEX 03-001, and the Vapure 612 carbon.
A-4
-------
ASZM-TEDA Carbon
20%
Carbon: ASZM-TEDA
Target Temp: 55±2 °C
Target RH: 50±5%
Runl
Average Temp: 53 °C
Average RH: 52.9%
Run2
Average Temp: 54 °C
Average RH: 52.6%
Run3
Average Temp: 53 °C
Average RH: 55.2%
15 20
Precondition Time (h)
25
30
35
Figure A-2. ASZM-TEDA (6 x 16 mesh) carbon bed weight gain versus preconditioning time
at 55 ± 2 °C and 50 ± 5% RH.
For ASZM-TEDA carbon, approximately 14 to 17 % of the weight gain was achieved during the
25 h of preconditioning, corresponding to a water vapor adsorption capacity of 0.14 to 0.17 g
water/g of carbon. As shown in Figure A-2, the carbon bed gained weight quickly within the first
four h of preconditioning, then the weight gain slowed dramatically. In the first run, the test was
stopped after 11 h of preconditioning as the weight gain, on average, had ceased indicating
saturation of the carbon bed. In the second and third runs, there was a consistent upward drift in
the weight gain, so the test was continued overnight and the weight gain was measured at t = 25 h
in the second run, and at t = 12, 14.5, 24, and 25 h in the third run. As shown in Figure A-2, the
carbon bed approached equilibrium after approximately 12 h of preconditioning, evidenced by the
fact that only 0.5 % of the weight gain was achieved in the last 13 h of preconditioning from 12 to
25 h during Run 3, which corresponds to only 3 % of the overall weight gain.
The test results show that the final weight gain or water adsorption capacity of ASZM-
TEDA carbon was very sensitive to operation temperature and RH. Slight variation in temperature
A-5
-------
and RH within the target ranges could cause measurable change in water adsorption capacity. For
example, during Run 3, the temperature was 1 °C lower and RH was 2.6 % higher than in Run 2,
which led to approximately a 13 % increase in water adsorption capacity. Based on these results,
preconditioning of the ASZM-TEDA carbon bed for (at least) 12 h at 55 ± 2 °C and 50 ± 5% RH is
considered sufficient.
IONEX 03-001 Carbon
15%
Carbon: IONEX 03-001
Target Temp: 55±2 °C
Target RH:50±5%
Runl
Temp: 53.6 °C
RH: 51.1%
Run2
Temp: 53.6 °C
RH: 52.2%
10 15
Precondition Tim (h)
Figure A-3. IONEX 03-001 (8 x 16 mesh) carbon bed weight gain versus preconditioning
time at 55 ± 2 °C and 50 ± 5% RH.
For IONEX 03-001 carbon, approximately 11 % of the weight gain was achieved during
the 24 h of preconditioning, corresponding to a water vapor adsorption capacity of 0.11 g water/g
of carbon. Rapid weight gain was observed in the first two to three hours in both Runs 1 and 2,
thereafter the weight gain slowed significantly. In the first run, the test was stopped after
approximately nine h of preconditioning as the weight gain had ceased, on average, indicating
saturation of the carbon bed. In the second run, the upward trend in the weight gain was
consistent, therefore the test was continued overnight, and weight gain was measured at t = 24 h.
As shown in Figure A-3, the weight gain approached equilibrium after ten h of preconditioning.
A-6
-------
The preconditioning test was continued for another 14 h from 10 to 24 h but the carbon only
achieved 0.6 % of additional weight gain, which corresponds to only 5 % of the overall weight
gain.
Based on the test results, preconditioning of the IONEX 03-001 carbon bed for (at least)
ten h is considered sufficient.
Norit Vapure 612 Carbon
Carbon: Norit Vapure 612
Target Temp: 55±2 °C
Target RH:50±5%
Runl
Temp: 53 °C
RH:54.6%
Run2
Temp: 54 °C
RH:51.9%
Run3
Temp: 53 °C
RH:53.1%
15 20
Precondition Time (h)
Figure A-4. Vapure 612 (6 x 12 mesh) carbon bed weight gain versus preconditioning time at
55 ± 2 °C and 50 ± 5% RH.
For Vapure 612 carbon, after 24 h of preconditioning, approximately 13 % and 9 %
weight gains were achieved, respectively, in Runs 1 and 3, and Run 2, which correspond to water
vapor adsorption capacities of 0.13 and 0.09 g water/g of carbon, respectively. The higher
weight gain obtained in Runs 1 and 3 was attributed to the slightly higher average RH (i.e., 54.6
% and 53.1 % in Runs 1 and 3 versus 51.9 % in Run 2) and slightly lower temperature (i.e., 53
°C in Runs 1 and 3 versus 54 °C in Run 2) during Runs 1 and 3. Unlike the ASZM-TEDA
carbon and the IONEX 03-001 carbon, the weight gain continued to increase after ten h of
preconditioning for Runs 1 and 3. Continued preconditioning from 10 to 24 h achieved 2.4 %
A-7
-------
and 1.3 % of additional weight gains, respectively, in Runs 1 and 3, which corresponds to more
than 15 % of the overall weight gain for all three runs. Therefore, as shown in Figure A-4 for
Vapure 612 carbon, it is necessary to precondition the carbon bed for (at least) 24 h.
In summary, the water adsorption capacities measured at 55 ± 2 °C and 50 ± 5 % RH
averaged 0.15, 0.11, and 0.11 g/g, respectively, for the ASZM-TEDA carbon, the IONEX 03-001
carbon, and the Vapure 612 carbon. For the ASZM-TEDA and IONEX 03-001 carbon, the
carbon bed approached equilibrium after 12 h of preconditioning. The Vapure 612 carbon
needed longer than 12 h to approach equilibrium. Based on the test results, it is recommended a
preconditioning time of at least 12 h for the ASZM-TEDA and the IONEX 03-001 carbons and a
preconditioning time of at least 24 h for the Vapure 612 carbon at the conditions of 55 ± 2 °C and
50 ± 5 % RH.
A.3.2 Carbon Bed Equilibrium Time at Dry Conditions (RH<15 %)
The measured plots of weight change of the ASZM-TEDA carbon versus preconditioning
time are presented in Figures A-5 to A-6, respectively, for the tests conducted at 55 °C and dry
conditions and 25 °C and dry conditions. As shown in Figures A-5 and A-6, the carbon bed
reached equilibrium within one hour at both test conditions. The carbon bed lost approximately 2
% of weight at 55 °C and 1 % of weight at 25 °C due to drying.
-------
ASZM-TEDA Carbon
-Run 1 -•— Run
Carbon: ASZM-TEDA
Target Temp: 55±2 °C
Target RH:0%
Runl
Average Temp: 54.1 °C
Average RH: 0.6%
Run2
Average Temp: 53.4 °C
Average RH: 0.3%
Precondition Time (h)
Figure A-5. ASZM-TEDA (6 x 16 mesh) carbon bed weight change versus preconditioning
time at 55 ± 2 °C and dry.
A-9
-------
ASZM-TEDA Carbon
.
BO
3
I
TO 71
u 2
-Run 1 —•— Run 2
Carbon: ASZM-TEDA
Target Temp: 25±2 °C
Target RH:0%
Runl
Average Temp: 25.0 °C
Average RH: 3.0%
Run2
Average Temp: 25.0<
Average RH: 2.7%
'C 5.00
Precondition Time (h)
Figure A-6. ASZM-TEDA (6 x 16 mesh) carbon bed weight change versus preconditioning
time at 25 ± 2 °C and dry.
The measured plots of weight change of the IONEX 03-001 carbon versus
preconditioning time are presented in Figures A-7 to A-8, respectively, for the tests
conducted at 55 °C and dry conditions and 25 °C and dry conditions. As shown in Figures
A-7 and A-8, the carbon bed reached equilibrium within one hour at both test conditions.
The carbon bed lost approximately 4 % of weight at 55 °C and 3 % of weight at 25 °C due
to drying.
A-10
-------
Carbon Bed Weight Gain (%)
o
lonex 03-001 Carbon
XV 1.
\
\
\
>{
-•—Run 1 -•— Run
30 2.
2
30 3.
DO
Carbon: lonex
Target Temp: 55±2 °C
Target RH:0%
Runl
Average Temp: 53.6 °(
Average RH:0.0%
Run2
Average Temp: 53.6°C
Average RH:0.0%
5.
30
Precondition Time (h)
Figure A-7. IONEX 03-001 (8 x 16 mesh) carbon bed weight change versus preconditioning
time at 55 ± 2 °C and dry.
A-ll
-------
lonex 03-001 Carbon
-Run 1 —»-Rur
_
Carbon: lonex
Target Temp: 25±2 °C
Target RH:0%
Runl
Average Temp: 25.3 °C
Average RH: 0.9%
Run2
Average Temp: 24.8°C
Average RH: 0.0%
Precondition Time (h)
Figure A-8. IONEX 03-001 (8 x 16 mesh) carbon bed weight change versus preconditioning
time at 25 ± 2 °C and dry.
The measured plots of weight change of the Vapure 612 carbon versus
preconditioning time are presented in Figures A-9 to A-10, respectively, for the tests
conducted at 55 °C and dry conditions and 25 °C and dry conditions. As shown in Figures
A-9 and A-10, the carbon bed reached equilibrium within one hour at both test conditions.
The carbon bed lost about 4.2 % of weight at 55 °C and 3.6 % of weight at 25 °C due to
drying.
Based on the test results, at conditions of 55 °C and dry and 25 °C and dry,
preconditioning of the ASZM-TEDA, IONEX 03-001, and Vapure 612 carbon beds for one h
is sufficient.
A-12
-------
Norit Vapure 612 Carbon
eight Gain (%)
g "-;
•o
01
m -1%
o
J2
ra .2%
-3%
-4%
D\ i.
\
\
\
-•—Run 1 -•— R
DO 2.
V ,
un2
DO 3.
50
Carbon: Vapure 612
Target Temp: 55±2°C
Target RH:0%
Runl
Average Temp: 54.8 °C
Average RH: 0.0%
Run2
Average Temp: 54.2 °C
Average RH: 0.0%
4.
' f
1
DO 5.
DO
Precondition Time (h)
Figure A-9. Vapure 612 (6 x 12 mesh) carbon bed weight change versus preconditioning
time at 55 ± 2 °C and dry.
A-13
-------
5%
4%
3%
E 2%
_C
'ro
13 1%
4-1
.C
BO
'53 ™, .
^ 0.
•o
01
ffl -1%
o
.Q
ra -2%
-3%
-4%
-5%
Norit Vapure 612 Carbon
\ '
\
\
\
-•-Run 1 -«-Rur
DO 2.
2
30 3.
' •
30
Carbon: Norit
Target Temp: 25±2 °C
Target RH:0%
Runl
Average Temp: 23.9 °C
Average RH: 2. 6%
Run2
Average Temp: 24.4 °C
Average RH: 2.4%
5.
Precondition Time (h)
30
Figure A-10. Vapure 612 (6 x 12 mesh) carbon bed weight change versus preconditioning
time at 25 ± 2 °C and dry.
A-14
-------
APPENDIX B: OPERATIONAL PARAMETERS FOR THE MINICAMSS
B-l
-------
Operating Conditions CMS-7, -
SN 2078
Method: NGS
TBYFHWlfK.'Xi
PRESSURES, psig
S/SMPLE(2UrrinLIVF):
VQLT/CtVDC
RHXRCMEI&t
TlVKJB/BnSsee:
Parameter
Arbiert
Net
Detector BOCK
DetedorRame
Coll IT'
Columnl.Lcw
Coiumn 1 , Hgh
Column I.Rate.tynin
Column 2. Hgh
Column 2, Rae.'C'min
PCT Heater
PCT Heater, Low
PCT Heater. Hgh
Ar
Carrier{Nitrogen)
Hydrogen
Row Rate, oar,
Ag. Row1 Rae, otrn
Vblume, L (g 2T
-------
OlAnalyticall ' m
Operating Conditions
S/N 2078
Method: MGM3
TEMPERATURES, °C:
PRESSURES, psig:
SAMPLE(2L/minLMF):
CMS Field Products
°arameter
Ambient
Inlet
Detector Block
Detector Flame
Column
Column 1,Low
Column 1,High
Column 1,Rate,°C/min
Column 2, High
Column 2, Rate, °C/min
PCT Heater
PCT Heater, Low
PCT Heater, High
Air
Carrier (Nitrogen)
Hydrogen
Flow Rate, ccm
Avg. Flow Rate, ccm
CMS-7, -
Setpoint
40
75
150
315
50
200
200
200
0
60
235
25
40
25
100
Volume, L@21°C,0 feet
VOLTAGE, VDC:
ELECTROMETER:
TIM ED EVENTS, sec:
CONCENTRATION REPORTS
FPD Photomultiplier
FPD Signal, nA
FID Signal, nA
Purge
Desorb
Column 2
Concn, Concn,
Cmpd Status mg/m3 MGM3
HD RUN
H2 RUN
0 0.00
0 0.00
600
29
71
0 - 180
5 - 60
150 - 150
Height,* Area,
nA nA-sec
0 0
0 0
11:19 05/01/2013
RUN
Actual
41
76
151
306
186
51
200
201
63
61
236
23
38
24
126
107
0.321
599
FPD Zero, nA
FID Zero, nA
Sample
Column 1
Alarm Setpoint,
RT, Width,
sec sec
0.0 0.0
0.0 0.0
NO ALARM
Limit
25
15
15
99
15
15
20
15
20
5
5
5
± 50
± 50
0
0
180- 360
60- 150
% MGM3 0
Gate Gate
On Off
143 152
143 152
* Concentration readings are based on peak height
CALIBRATION INFORMATION:
Cmpd Pet
MGM3
Level
Date
Time
Height,* Area,
nA nA-sec
RT,
sec
Width, Gate Gate
sec On Off
HD
H2
FPD
FID
1.0 04/29/2013 12:05
1.0 04/29/2013 12:06
1059922
116
3301759
340
148.7
147.6
143
143
152
152
SAMPLING SEQUENCE:
SOFTWARE: 07022007 ELAPSEDTIME: 154 sec
Printed: 5/2/2013 11:25AH
Facility: HHRC(Host3) Station: Station 7
Analysis: 60493
Figure B-2. Operational parameters of the MINICAMSR for HD detection.
B-3
-------
APPENDIX C: PLOTS OF GB AND HD CHALLENGE CONCENTRATIONS,
TEMPERATURE, RH, FLOW RATE, AND AP
C-l
-------
1400
1200
\ 1000
^
J
= 800
P5
O
™ 600
_^
A
U
400
200
* •
•
Carbon: ASZM-TEDA
Bed depth: 2.5 cm
25 °C/dry
Average Co - 1,313 mg/m3
20 30
40 50 60
Time (min)
60
30
20
^— Desorption started
ooooooooooo
Flow Rate (L/min)
OT (°C) -Top of Carbon Bed
RH (%)*
OOOOOOOOOOQOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
oooooooooooooooooooooooooooooooooo
1 2
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
Figure C-l. ASZM-TEDA (6 x 16 mesh) carbon, 2.5 cm bed depth, 25 °C/dry.
C-2
-------
l>
Carbon: ASZM-TEDA
Bed depth: 3.0 cm
25 °C/dry
Average Co = 1,405 mg/m3
*.
100 150
Time (min)
60
<—Desorption started
•> Flow Rate (L/min)
OT (°C) -Top of Carbon Bed
RH (%)*
10
5 10 15
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
20
Figure C-2. ASZM-TEDA (6 x 16 mesh) carbon, 3.0 cm bed depth, 25 °C/dry.
C-3
-------
1,400
1,200
g 800
"s
U
§ 600
200
Carbon: ASZM-TEDA
Bed depth: 3.5 cm, Run 1
25 °C/dry
Average Cone. = 1,511±65 mg/m3
10 20 30 40 50 60
Time (min)
80 90
o Flow Rate (L/min)
OT (°C) -Top of Carbon Bed
RH (%)*
o o o o o o o
ooooooooo
Carbon: ASZM-TEDA
Bed Depth: 3.5 cm
25 °C/dry, Run 1
AAAAAAAAAAAAAAAA
0.5 1.0
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
** Adsorption test suspended at 1.3 hrs, due to MINICAMs baseline drifting
Figure C-3. ASZM-TEDA (6 x 16 mesh) carbon, 3.5 cm bed depth, 25 °C/dry, Run 1.
C-4
-------
"DC
•S-
"s
^
U
g 600
/inn
•
c
10
.••••".•
Bed depth: 3.5 cm, Run 2
25 °C/dry
Average Co = l,206±109mg/m3
20 40 60
< — Desorption started
i^™
»
«
* »
80 100 120 140
Time (min)
* * * *
160 180 200
>> Flow Rate (L/min)
OT (°C) -Top of Carbon Bed
iRH(%)*
Carbon: ASZM-TEDA
Bed Depth: 3.5 cm
25°C/dry, Run 2
5 10 15
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
Figure C-4. ASZM-TEDA (6 x 16 mesh) carbon, 3.5 cm bed depth, 25 °C/dry, Run 2.
C-5
-------
a
a
u
1
J
C!
u
Carbon: lonex
Bed depth: 3.5 cm
25°C/dry,Runl
Average Co = 1,600±412 mg/m3
*»*****<
»*»
»,»******
Impinger ran
outofGB
>»*»***«»***
>
•
*
<
Restarted
£- next day
» »***
^ *
**
•
100
Time (min)
40
^ Desorption started
Flow Rate (L/min)
OT (°C) -Top of Carbon Bed
RH (%)*
10
I 0
5 10 15
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
20
Figure C-5. IONEX 03-001 carbon, 3.5 cm bed depth, 25 °C/dry, Run 1.
C-6
-------
sr- 1,500
"a
u
O
u
s
Carbon: lonex
Bed depth: 3.5 cm
25 °C/dry, Run 2
Average Co = 1,391±36 mg/m3
60
150 200
Time (min)
Desorption started
5 10 15
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
Flow Rate (L/min)
OT (°C) -Top of Carbon Bed
RH (%)*
Figure C-6. IONEX 03-001 carbon, 3.5 cm bed depth, 25 °C/dry, Run 2.
C-7
-------
U
P5
O
,»***»
»*»,
Carbon: lonex Carbon
Bed Depth: 3.5cm
55oC/dry, Run 1
Average Cone. - 1,569± 86mg/m3
50 100 150 200
Time (min)
^— Desorption Started
•> Flow Rate (L/min)
o T (°C) -Top of Carbon Bed
RH(%)*
5 10 15
Time (h)
4, was monitored at a location before addition of the challenge GB.
Figure C-7. IONEX 03-001 carbon, 3.5 cm bed depth, 55 °C/dry, Run 1.
C-8
-------
^— Desorption Started
Carbon: lonex
Bed Depth: 3.5 cm
55 °C/dry, Run 1
Avg. AP = 0.23±0.0023 INCH H2O
Time (h)
Figure C-8. IONEX 03-001 carbon, 3.5 cm bed depth, 55 °C/dry, Run 1 (Continued).
C-9
-------
„
I
a
_o
"a
U
03
O
3
Carbon: lonex
Bed depth: 3.5 cm
55 °C/dry, Run 2
Average Co = 1,600+656 mg/m3
4
**
•
4
*$+*********
»
**»
***
A
0 50
40 -
in -
0 -
100 150 200 250
Time (min)
300
35
< — Desorption started
IT
^
r'low Rate (L/min)
0 T (°C) -Top of Carbon Bed
RH (%)*
Carbon: lonex
Bed Depth: 3.5 cm
55°C/dry, Run 2
5 10 15
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
Figure C-9. IONEX 03-001 carbon, 3.5 cm bed depth, 55 °C/dry, Run 2.
C-10
-------
l<— Desorption Started
°,015
H
Carbon: lonex
Bed Depth: 3.5cm
55 °C/dry, Run 2
Avg. AP - 0.23±0.003 INCH H2O
10
Time (h)
nonitored at a location before addition of the challeni
igeGB.
Figure C-10. IONEX 03-001 carbon, 3.5 cm bed depth, 55 °C/dry, Run 2 (continued).
C-ll
-------
2,000
1,400
t 1,200
a
400
200
50
100
150 200
Time (min)
Carbon: Vapure 612
Bed Depth: 3.5 cm
25°C/dry, Run 1
Average Cone. = 1,678±73 mg/m3
250
300
350
Desorption started
5 10 15
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
Flow Rate (L/min)
OT (°C) -Top of Carbon Bed
RH (%)*
Figure C-ll. Vapure 612 carbon, 3.5 cm bed depth, 25 °C/dry Run 1.
C-12
-------
2,000
1,400
ID 1,200
s
-
o
400
200
» »»»»»*
•
**»»»*»*», »,
50
100
150 200
Time (min)
Carbon: Vapure 612
Bed Depth: 3.5 cm
25°C/dry, Run 2
Average Cone. = 1,531±48 mg/m3
300
350
Desorption started
5 10 15
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
Flow Rate (L/min)
OT (°C) -Top of Carbon Bed
RH (%)*
Figure C-12. Vapure 612 carbon - 25 °C/dry, 3.5 cm bed depth, Run 2.
C-13
-------
Carbon: Vapure612
Bed depth: 3.5cm
55°C/dry,Runl
Average Cone. - 1,469±85 mg/m3
*****
, #»»
u
P5
O
150 200
Time (min)
60
• Desorption started
o Flow Rate (L/min)
OT (°C) -Top of Carbon Bed
RH (%)*
10
5 10 15
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
20
Figure C-13. Vapure 612 carbon - 55 °C/dry, 3.5 cm bed depth, Run 1.
C-14
-------
p^— Desorption Started
O
tf
Carbon: Vapure 612
Bed Depth: 3.5cm
55°C/dry, Run 1
Avg. AP = 0.14±0.0013 INCH H2O
Time (h)
Figure C-14. Vapure 612 carbon - 55 °C/dry, 3.5 cm bed depth, Run 1 (continued).
C-15
-------
Carbon: Vapure612
Bed depth: 3.5cm
55 °C/dry, Run 2
Average Cone. - 1,259±128 mg/m3
* * *
U
P5
O
100 150
Time (min)
60
^ Desorption started
o Flow Rate (L/min)
OT (°C) -Top of Carbon Bed
RH (%)*
5 10 15
Time (h)
*RH% was monitored at a location before addition of the challenge GB.
20
Figure C-15. Vapure 612 carbon - 55 °C/dry, 3.5 cm bed depth, Run 2.
C-16
-------
o
tf
Carbon: Vapure 612
Bed Depth: 3.5cm
55 °C/dry, Run 2
Avg. AP = 0.1410.0018 INCH H2O
Time (h)
Figure C-16. Vapure 612 carbon - 55 °C/dry, 3.5 cm bed depth, Run 2 (continued).
C-17
-------
25 0 -i
_ 20.0 -
g
£
tS 15.0 -
0)
a.
w
i— -in n
5.0 -
— r-> • . —
\ Thallenge end
at 136 minutes
17.29 g ASZM TEDA 12 x 30 mesh
Bed depth* ^ 5 cm
25°C/<10%RH
Target challenge: 1500 mg/m3
t_riaiicnge i iriie. .LOO rrinULcs
% RH
9.0
8.0
7.0
6.0
- 5.0 o:
tf1*
4.0
3.0
2.0
1.0
0 5OO 1OOO 1500
Time (minutes)
Figure C-17. Temperature and RH measurement for GB adsorption/desorption on ASZM-
TEDA (12 x 30 mesh) carbon at 25 °C/dry conditions.
i
•a
u
A
B.
B.
^3 *"^**
ifl ^
« ™
a.
2
c
u
•_
u
t
00
0 25 -
00
01 R
01 .
One
c
* ^ Challenge end at 136 minutes
) 200 400 600 800 1000 1200 1400 1600
Time (minutes)
Figure C-18. Pressure differential measurement (upper bed) for GB adsorption /
desorption on ASZM-TEDA (12 x 30 mesh) carbon at 25 °/dry conditions.
C-18
-------
r,ll j
ill 0
v*
C ann
• .11.'
|
|— . « . I.
10.0
nn
l
i ion
9JO
f*
^ ••.
17.29s ASZM TEDA 12 x 30 mesh
C^--i'A/^r1lnlil'OLJ 7fl
JT Lf v lv' 7^ Fin • JU
Awef^geCBChgllenge: . ^j
Challenge Time 145 minutes
^\ 4JI
fcRU
1.0
- nn
1 200 400 600 800 ]:OU 1MO 1*50
Time (minute?)
Figure C-19. Temperature and RH measurement for GB adsorption/desorption on ASZM-
TEDA (12 x 30 mesh) carbon at 55 °C/dry conditions.
5
I
^* n ^>
5 u-^
CQ
Ol
a.
°- n i c.
1
a) 01
D.
To
S
a* n n^
£
a
c
^\
Challenge ends at 149 minutes
» 2OO 4OO 6OO 8OO 1OOO 12OO 14OO
Time (minutes)
Figure C-20. Pressure differential measurement (upper bed) for GB adsorption/desorption
on ASZM-TEDA (12 * 30 mesh) carbon at 55 °C/dry conditions.
C-19
-------
25.0 -
£
1
ts 1 ^ n
a.
1
<. — Challenge ends at 381 minutes
L.L..
— — 1— L -J-
lonex carbon weight: 13.73g
Bed depth: 2.5 cm
Test condition: 25 °C/dry
Average HD challenge:
547±46mg/m3
Challenge time: 381 minutes
Temperature %RH
- 14.0
12.0
- 8.0 i
ft
*
6.0
- 4.0
- 2.0
0 200 400 600 800 1000 1200 1400 1600
Time (minutes)
Figure C-21. Temperature and RH measurement for HD adsorption/desorption on IONEX
03-001 carbon at 25 °C/dry conditions.
n i/
u
5
• n 1">
•o U.12
V
CO
n 1
5
Q.
Q.
^ ^— K n no
J Q^ U.Uo
•t n n4
Q
01
^ n m
£
u
i n
C
Challenge ends at 381 minutes
1 200 400 600 800 1000 1200 1400 1600
Time (minutes)
Figure C-22. Pressure differential measurement (upper bed) for HD adsorption/desorption
on IONEX 03-001 carbon at 25 °C/dry conditions.
C-20
-------
en pi
u1
o
§
™ ann
4J
1
20 0
c
^^^ Upper Cell Temp
Challenge RH
^ Challenge ends at 390 minutes
lonex carbon weight: 13.73g
Bed depth: 2.5cm
IC3L CUITUTITUIT. J3 \^/ U 1 y
Average HD challenge:
508 ± 170mg/m3
Challenge time: 390 minutes
) 200 400 600 800 1000 1200 1400 1600 1800 20
Time (minutes)
- 9.0
8.0
7.0
- 6.0
X
c n Q£
5?
4.0
- 3 0
- 2.0
- 1.0
00
Figure C-23. Temperature and RH measurement for HD adsorption/desorption on IONEX
03-001 carbon at 55 °C/dry conditions.
u
~a
V
CQ
•_
V
n.
n.
oT ^i
3 X
3 =
ii •—
a.
|5
C
Of
l_
t
5
Oifi
0.14 -
01 ~>
01 .
Ono
One, _
OfM -
009
c
^ " Challenge ends at 390 minutes
I 200 400 600 800 1000 1200 1400 1600
Time(minutes)
Figure C-24. Pressure differential measurement (upper bed) for HD adsorption/desorption
on IONEX 03-001 carbon at 55 °C/dry conditions.
C-21
-------
60.0
50.0
40.0
30.0
20.0
10.0
0.0
Jonex-Carbon: 13,73 g
Bed depth: 2.5cm
55 °C/ 50 % RH
-HD-Owllenge:
482 ± 98 mg/m3
Challenge Time: 347 minutes
MINICAMS MFC failure
resulted in
early conclusion
~oTfesT(no desorption)
90.0
- 50.0
40.0
30.0
20.0
10.0
I
SSL
0.0
100
200
300
Time (minutes)
400
500
600
Figure C-25. Temperature and RH measurement for HD adsorption/desorption on IONEX
03-001 carbon at 55 °C/humid conditions.
0.25
Upper Bed
Lower Bed
Challenge ends
0
100 200
Time (minutes)
300
400
Figure C-26. Pressure differential measurement (upper and lower bed) for HD
adsorption/desorption on IONEX 03-001 carbon at 55 °C/humid conditions.1
1 Pressure drop measurements were made above and below the test bed relative to ambient pressure in all tests. Pressure drop
results for tests were typically identical at both locations and maintained consistent values. For this test, there was a difference
noted between the upper and lower pressure drop measurements. Further, a decreasing trend in pressure drop was noted during
the challenge test period (347 minutes). It is unclear whether the changes in pressure drop could be associated with the formation
of TDG (and subsequent condensation) on the carbon bed.
C-22
-------
1 AH
1 9H
"=• c
'E 1 nn
E sn
a fin
O /in
LL.
lfl
S ?n
1
Zn
i (
9n
An
|d Beginning of
pdD= -taniiiinyt:^^^^ - flow issues at
ZTJO 1 1 1 1 1 1 U LC J
.^
Time (minutes)
Figure C-27. MINICAMS sampling flow rate capture data for IONEX 03-001 carbon at
55 °C/humid conditions.
C-23
-------
3U.U
25.0 -
,— - ^n n
£20.0
T
•M 1 cr n
i_
Q)
Q.
u
I— 1 n n
5n
n n -
Up
Te
^ Challenge ends at 355 minutes
per Cell
nperature (oC)
IH
"™1 B^L** ASZM TEDA 12 x 30 mesh: 17.29 g
Bed depth: 2.5cm
25°C/<10%RH
Avg HU challenge:
576±180mg/m3
Challenge Time: 355 minutes
- a.u
- 8.0
- 7.0
6n
- 5.0 x
te.
- 4.0 S
T n
- 2.0
- 1.0
n n
0 200 400 600 800 1000 1200 1400 1600
Time (minutes)
Figure C-28. Temperature and RH measurement for HD adsorption/desorption on ASZM-
TEDA (12 x 30 mesh) carbon at 25 °C/dry conditions.
n ^R
u 03b
_r n T .
^ U.Ji
BO
o 0 25
&
Q.
^ W n T
- u u.z
$ c n 1 c;
| «, 0.15
T5 n 1
1
£ 005
5 n
u
(
"^ Challenge ends at 355 minutes
1 1 1 1 1 1 1 1
) 200 400 600 800 1000 1200 1400 1600
Time (minutes)
Figure C-29. Pressure differential measurement (upper bed) for HD adsorption/desorption
on ASZM-TEDA (12 x 30 mesh) carbon at 25 °C/dry conditions.
C-24
-------
fin n
50.0 -
/in n
tj 4au
o
<•_*
1
** on n
n oU.U
V
&
V
i_ Tn n
100
o n -
(
/
^\ Challenge ASZM TEDA 12 x 30 mesh 17'29 g
endsat34( Bed depth: 2.5cm
minutes •>•> <- / *• 1U /0 KH
Challenge Concentration:
527±60mg/m3
Challenge time: 346 minutes
— Upper Bed Temp (oC
% RH
i | 1
i
I 200 400 600 800 1000 1200
Time (minutes)
1
14
mn
- 9.0
- 8.0
- 7.0
- 6.0
z
S?
- 4.0
- 3.0
- 2.0
- 1.0
n o
00
Figure C-30. Temperature and RH measurement for HD adsorption/desorption on ASZM-
TEDA (12 x 30 mesh) carbon at 55 °C/dry conditions.
u
§
•a
to
b
V
Q.
Q.
*s
LA C
£ ~
CL
to
*•£
£
V
5
Oq
0.45
OA
O^^L
00
OTC
0~)
01 ^
01
One
c
<— Challenge ends at 346 minutes
) 200 400 600 800 1000 1200 1400
Time (minutes)
Figure C-31. Pressure differential measurement (upper bed) for HD adsorption/desorption
on ASZM-TEDA (12 x 30 mesh) carbon at 55 °C/dry conditions.
C-25
-------
e;n n
Z>U.U -
40 0 -
£
£
fon n
01
D.
E
1— on n -
1 n n
On
t
f "'^ ' ^.. ,
<-i — Challenge ends at 366 minutes
ASZM TEDA 12 x 30 mesh 17.29 g
Bed depth: 2.5cm
55 °C/ 20 % RH
514±24mg/m3HD
Challenge Time: 366 minutes
UiMUil , i
QUttHBjL UII..J Ji. Ml.iiJJJ.il.
H^VB***" i««^»i
• Mnnpr RpH T^ITlD (o1^
%RH
) 200 400 600 800 1000 1200 1400 16
Time (minutes)
on n
- 70.0
- 60.0
- 50.0
I
/inn o£
Sfi
- 30.0
- 20.0
- 10.0
On
00
Figure C-32. Temperature and RH measurement for HD adsorption/desorption on ASZM-
TEDA (12 x 30 mesh) carbon at 55 °C/humid conditions.
•a
•u
CO
te
01
a.
Q.
3
£
3
8
01
^
Q.
"ra
?
£
4»
^
5
Oc
0/1 R
0/1
n ^^
00
O n 7^
*ft U.Z^
X
C" n *3
n 1 R
01
One _
n nR
< — Challenge ends at 366 minutes
P^M^fc
^l*
^^V^'^^i^^^Vl
T
1
) 200 400 600 800 1000 1200 1400 1600
Time (minutes)
Figure C-33. Pressure differential measurement (upper bed) for HD adsorption/desorption
on ASZM-TEDA (12 x 30 mesh) carbon at 55 °C/humid conditions.
C-26
-------
1.5
D.
£ 0.5
1
-0.5
-Sample Flow Rate
MINICAMS MFC fails
at 666 minutes
200
400
600
800
1000
Time (minutes)
1400
1600
-1®
Figure C-34. MINICAMS sampling flow rate capture data for ASZM-TEDA (12 x 30
mesh) carbon at 55 °C/humid conditions.
C-27
-------
°0 0
25.0 -
£
ts -i c n
V
£
10 0
0 0
•^ ' Challenge ends at 337 minutes
i n rt
^"^^i
20.68 g ASZM TEDA 6 x 16 mesh
25°C/< 10%RH
HD Challenge concentration
534 ± 70 mg/m3
Challenge Time: 337 minutes
^^^ _ -M II f*~"
Challenge Temperature,
I Jnn^r Tpll
Challenge % RH
0 500 1000
Time (minutes)
9.0
- 8.0
- 7.0
6 0
X
c n oc
se
- 4.0
- 3.0
2.0
- 1.0
n n
1500
Figure C-35. Temperature and RH measurement for HD adsorption/adsorption on ASZM-
TEDA (6 x 16 mesh) carbon at 25 °C/dry conditions.
u
•o
at
to
k
V
D.
*S
I.E
2-
a.
n
1
£
V
£
Q
01
Onp
OnR
Om
One
Or\A
Onq
On*?
Om
t
<— Challenge ends at 337 minutes
) 200 400 600 800 1000 1200 1400 1600
Time (minutes)
Figure C-36. Pressure differential measurement (upper bed) for HD adsorption/desorption
on ASZM-TEDA (6 x 16 mesh) carbon at 25 °C/dry conditions.
C-28
-------
United States
Environmental Protection
Agency
PRESORTED STANDARD
POSTAGE & FEES PAID
EPA
PERMIT NO. G-35
Office of Research and Development (8101R)
Washington, DC 20460
Official Business
Penalty for Private Use
$300
------- |