U.S. Navy's Final Report
Katec Aerosolv® Technology Field Test Demonstration
Summary of Results
I. BACKGROUND
Katec Inc. entered into an agreement with the U.S. Environmental Protection
Agency (EPA) and the California Environmental Protection Agency for federal
verification and state certification of the Aerosolv® technology.
The technology consists of an aerosol can puncturing/draining device that
is threaded into the large bung hole at the top of a 55-gallon drum; a
coalescing filter assembly that is threaded into the small bung hole of
the drum; and a 30-gallon drum carbon filter canister, see enclosure (1)
of Appendix I. Liquids discharged from the puncturing/draining device
are collected in the collection receptacle. Non-condensable gases and
volatile fractions are diverted through the coalescing filter and adsorbed
onto the carbon. Empty cans resulting from the process are recycled as
scrap metal.
In November of 1996, Katec approached the U.S. Navy for assistance in
developing and performing the Field Test Demonstration outlined in the
Field Test Plan. Katec selected the Navy for five reasons:
- The Navy is the largest generator of hazardous waste aerosol cans
in California.
- California Assembly Bill 483 authorized hazardous waste aerosol can
generators to use certified aerosol can recycling technologies without
extensive permitting or authorization requirements. Commander Naval
Base, San Diego (CNBSD) and the Navy Public Works Center (PWC), San
Diego, Environmental Department were searching for an aerosol can recycling
technology manufacturer who would be willing to obtain certification
in the State of California. CNBSD and PWC offered to provide a test
demonstration site, a large inventory of aerosol cans, and the labor
to operate and test the Aerosolv® technology.
- The Navy generates a larger variety and diversity of aerosol can products
than any other industrial user in California.
- The Navy was instrumental in the development of the Aerosolv®
technology at the Naval Operations Base in Norfolk Virginia.
- CNBSD and PWC are extremely cognizant of the regulatory issues associated
with aerosol can management. For further discussion of regulatory status,
please see discussion at the end of this document.
PWC began conducting the Field Test Demonstration in accordance with
the approved Field Test Plan on August 5, 1998. The test concluded on
November 19, 1998. This document summarizes the results of the demonstration
conducted by the Navy.
- FIELD TEST OBJECTIVES
- Removal
- Removal of hazardous waste to 3% of capacity:
Determine the ability of the technology to remove hazardous waste
such that less than 3% of the original capacity of hazardous waste
remains. This is consistent with the federal definition of an empty
container.
The results indicated that 98.6% of the cans contained
less than 3% residual by weight of the total capacity after puncturing.
This residual was comprised of both hazardous and non-hazardous material.
- Removal of hazardous waste to the maximum extent
practical: This is consistent with California's specific
aerosol can regulations for hazardous waste. California developed
specific regulations for aerosol cans because none existed previously.
DTSC and PWC representatives noted that each of the
cans processed were emptied to the maximum extent practical.
- Removal efficiency: Determine
the 90% confidence limit of the mean removal efficiency.
The test results indicated that the Aerosolv®
technology captured 95% of the total product discharged. Removal efficiency
calculations are presented in Appendix XIII.
- System Capture Efficiency
- Determine the percent of gaseous and liquid
contents removed from the processed cans that is captured by the Aerosolv®
technology.
Mass balance discharge and Aerosolv® system
collection results indicated that 95% of the materials discharged were
removed and captured by the Aerosolv® technology.
- Carbon Filter Effectiveness
- Determine the total mass of the contents of
aerosol cans processed by the Aerosolv® technology
resulting in carbon filter breakthrough emissions and the mass resulting
in carbon filter changeout in accordance with criteria established
in the Field Test Plan.
For each type of material processed, an analysis was
conducted to calculate the cumulative number of grams discharged when
the carbon filter exhaust monitor reached 100,000 ppm. Not surprisingly,
the values varied depending on the material; indicating that there
is no obvious or direct correlation of mass discharge and filter saturation.
For the five filters utilized during the paint processing, the filters
emitted 100,000 ppm at an average of 16,800 grams of paint discharged.
For corrosion preventative compound (CPC), 42,000 grams was discharged
prior to the first filter emitting 100,000 ppm. The 100,000 ppm threshold
was not reached on the second CPC filter after 35,000 grams was discharged.
The filter for the Brakleen® never reached the 100,000
ppm threshold even though 46,000 grams was discharged through the
unit. In fact, the Brakleen® filter never exceeded
an exhaust emissions reading in excess of 3.88 ppm.
Target compounds were not detected at the 90% carbon
filter effectiveness (100,000 ppm) threshold established in the Field
Test Plan for carbon change-out. As such, a more appropriate basis
for determining carbon change-out is when emissions of target compounds
from the carbon bed exhaust are detected in the breathing zone at
concentrations exceeding Occupational Safety and Health Administration
(OSHA) permissible exposure limits (PELs). This action point for carbon
changeout was never reached during the field test. Based on Field
Test results, PWC recommends that carbon changeout occur after continuous
or sustained processing well in excess of 2,000 cans (for more detailed
information see Appendix XIII).
- Measure the total organic vapor concentrations
in carbon filter breakthrough emissions and assess their risks to
worker health and safety.
With respect to any emissions coming off of the carbon
filter, no target compounds were found at laboratory reporting limits;
thus the emissions were propellants. Health risks associated with
the propellants are identified in Table 1, Enclosure (3), of Appendix
I. Monitoring results support the conclusion that employees were not
exposed above OSHA PELs, National Institute of Occupational Safety
and Health (NIOSH) recommended exposure levels (RELs) or American
Conference of Governmental Industrial Hygienist (ACGIH) RELs.
- Assess the adequacy of the established standard
operating procedures in determining when the carbon filter needs replacement.
The standard operating procedure for the Aerosolv®
unit recommends changing the filter when the granules contained within
the colorimetric indicator change color from magenta to black. The manufacturer
designed the indicator to be sensitive to the target compounds and not
to propellant gases. As noted in the field logs the colorimetric indicator
was monitored during the Test Runs and changes in color were observed.
At no time was any indicator observed to turn black. These observations
support the field monitoring data that target compound saturation was
never reached. At the 100,000 ppm threshold carbon beds were still effective
in capturing target compounds and minimizing worker health and safety
concerns (see specifically the Brakleen® Test Runs).
PWC recommends that additional language in the SOP clarify that the
colorimetric indicator color change is gradual, but saturation is not
indicated until it turns black.
- Assess Worker Health and Safety in Operating the Aerosolv®
Technology
- Determine the capability of the Aerosolv®
technology to operate such that the vapor/gaseous emissions within
the operator's breathing zone do not exceed the allowable daily exposure.
Workplace monitoring results indicated that PWC
employees were not exposed to vapor/gaseous emissions within the operator's
breathing zone above OSHA PELs. Breathing zone exposure results are
contained in Appendix I, Section 3 of the Report.
- Determine the capability of the Aerosolv®
technology to operate such that the vapor/gaseous emissions within
the operator's breathing zone do not exceed other regulatory limits.
Workplace monitoring results indicated that PWC
employees were not exposed to vapor/gaseous emissions within the operator's
breathing zone in excess of other occupational exposure limits recommended
by NIOSH and ACGIH. Breathing zone exposure results are contained
in Appendix I, Section 3 of the Report.
- Determine the potential for emissions
from operation of the Aerosolv® technology to exceed
10% of the LEL.
Workplace monitoring results indicated that 99.96%
of the total data points collected were less than the lower explosion
action limit (LEL) of 1% (10,000 ppm). LEL monitoring results are
contained in Appendix I of the Report.
- Determine the effectiveness of the technology
in preventing releases of the liquid contents of the aerosol cans.
- Field Test Results
Objective 1a: Removal of Hazardous Waste to 3% of Capacity
PWC began collecting aerosol cans for the Field Test Demonstration in
November of 1996. Over 25,000 cans were collected and segregated according
to class, family, and species as indicated in the PWC Standard Operating
Procedure #931-96-006, Aerosol Can Management. Due to changes in the development
of the Field Test Plan and regulatory restrictions regarding treatability
studies and the storage of aerosol cans, the cans were sorted and inventoried
on three separate occasions. The final segregation and inventory was conducted
in response to the November 20, 1997 Draft Field Test Plan. As a result
of that segregation and inventory process, PWC provided a list of the
various types and constituents contained in each can to be evaluated.
DTSC had originally proposed that:
- Test Run #3 be conducted solely on So-Sure Lacquer
Green 14110;
- Test Run #4 be conducted on Eco-Sure Gray Spray
Paint 16099;
- Test Run #5 be conducted on either Eco-Sure
or So-Sure paint;
- Test Runs #6 and #7 be performed on Aerokroil
penetrating oil; and
- Test Runs #8 and #9 be performed on Polytech®
TG-452 aerosol cleaner.
PWC personnel segregated the paints into Eco-Sure and So-Sure paints
and demonstrated that the each type of paint contained similar constituents.
PWC also demonstrated that So-Sure CPC was more prevalent than Aerokroil
and Brakleen® was a more prevalent than TG-452. As a result,
PWC requested and received verbal permission to:
- Evaluate any approved type of So-Sure paint
in place of the green lacquer;
- Evaluate any approved type of Eco-Sure paint
in place of the gray spray paint
- Substitute So-Sure CPC for Aerokroil; and
- Substitute Brakleen® for TG-452.
Katec further requested that the field test evaluate 3-25% full cans
as opposed to full cans as originally requested by DTSC. Katec made this
request because in the real world, very few cans in the spent aerosol
can waste stream are more than 25% full. In fact, most are 3% to 15% full.
However, because of time constraints, and with the approval of DTSC, full
cans were processed through the carbon beds. In fact, DTSC representatives
requested the processing of full cans during Test Run #1 (Eco-Sure paint).
DTSC later revised the Field Test Plan to incorporate these requests.
PWC performed Test Run #1 on 352 Eco-Sure High-Solids enamel paint cans
and Test Run #2 on 1132 So-Sure paint cans. At the conclusion of Test
Run #2, PWC requested to bypass Test Run #3 based on the length of time
required to conduct the previous tests, the shortage of Eco-Sure High-Solids
enamel paint cans with between 3% and 25% residual prior to puncturing,
and the apparent collection of sufficient data. DTSC permitted PWC to
proceed with Test Run #4 while it evaluated the need to conduct Test Run
#3.
At the conclusion of Test Run #4 DTSC decided that Test Run #3 was necessary
and further requested that PWC not proceed with any other Test Runs until
75 paint cans were randomly selected and cleaned for tare weight determination.
PWC personnel consulted with DTSC representatives and selected 100 post-treated
cans from Test Run #2 for the purpose of cleaning and tare weight determination.
These cans were collected in a separate box and put aside. DTSC representatives
then assisted PWC personnel in selecting an appropriate can opener and
observed the can opening and cleaning process.
During the cleaning process, PWC and DTSC representatives realized that
the polymerized paint solids adhered to the side of the cans was extremely
difficult to remove. At that time PWC inquired as to the validity of including
the weight of this dried, solid, polymerized, non-hazardous material in
the tare weight determination. PWC argued that the 3% criteria outlined
in 40 CFR 261.7 did not include non-hazardous material. The polymerized
paint solids discovered were definitely non-hazardous.
As such, in accordance with page 4 of the Field Test Plan, PWC requested
that the tare weight procedure be modified because it was inadequate with
regards to the verification process. Specifically, the procedure as written
included the weight of this non-hazardous residue.
Paint
First Evaluation: So-Sure paint cans from Test
Run #2, deficient of exterior paint, tape, labels, or other discretionary
debris, were selected in the presence of DTSC personnel to ensure
the integrity of the tare weight results. Over 1100 So-Sure paint cans
were evaluated. The majority of these cans contained less than 15% product
(estimated based on pre-treatment weight) prior to treatment. These cans
were collected over a period of two years. PWC selected So-Sure paint
because the chemical formulation of So-Sure paint represents the most
common type of paint used both commercially and by the military.
The random selection process resulted in evaluation of So-Sure paint
cans with post-treatment weights less than 110 grams. This sampling represented
60% of the total So-Sure paint can pool. The cans selected had post-treatment
weights ranging from 96.32 grams to 109.96 grams, a variance of 13.64
grams. Original nominal capacity weights ranged from 283 grams to 361
grams with an average of about 300 grams. Given that the lowest post-treatment
weight recorded for the entire paint can pool was 94.00 grams, it was
reasonable to suspect that the tare weight of the paint cans would probably
be less than 94.00 grams. Further, using an average nominal capacity weight
of 300 grams, one could quickly determine that 3% of the original contents
would equate to approximately 9.0 grams.
Based on these preliminary calculations, PWC hypothesized that cans with
post-treatment weights in excess of 103 grams (94 grams of tare weight
plus 9 grams of residual) would not meet the 3% criteria. Therefore, 33
of the 75 cans would not meet the 3% criteria. PWC further hypothesized
that the residual percentage would increase linearly as the post-treatment
weights elevated above 94.0 grams. As such, a can registering a post-treatment
weight of 97.0 grams would maintain a 1% residual volume, a can registering
a post-treatment weight of 100.0 grams would demonstrate a 2% residual
volume, a can registering a post-treatment weight of 103 grams would demonstrate
a 3% residual volume, and so on. As such, PWC expected over 40% of the
So-Sure paint cans randomly selected to retain residual volumes in excess
of 3% because their post-treatment weights exceeded 103 grams.
Tare weight results (provided in Appendix II) did not support our hypotheses.
Over 75% of the cans were emptied by the Aerosolv® technology
to less than 1.5% of their original capacity. Over 90% of the cans were
emptied to less than 2.0% of their original capacity. All of the cans
were emptied to less than 3.0 % of their original capacity. Further, the
results showed no relationship between post-treatment weights and percent
residual remaining. Cans with post-treatment weights of 102 grams had
percent residual volumes between 1.3% and 1.8%, while cans with average
post-treatment weights of 109 grams had percent residual volumes between
0.4% and 1.8%.
Definite trends highlighted by the results indicate that the percent
residual remaining in the can is truly a function of the can and the technology
design. During the processing of each can, DTSC and PWC representatives
noted that the design of the Aerosolv® technology puncturing
device punctures the can just above the lip formed at the top of the can.
The contents of the can are allowed to drain through the hole; however,
the cup that's created captures material collected in the lip of the can.
This minimal volume of material is consistent for each can. Therefore,
the percentage of material that remains becomes a function of the total
original capacity of the can and not of the technology's ability to empty
specified types of material. Analysis of the tare weight results indicates
that all seven cans with percent residual volumes over 2% had total original
capacities less than 300 grams.
Second Evaluation: DTSC selected a combination
of Eco-Sure and So-Sure cans for the second tare weight evaluation. The
cans selected were as follows: 19 Eco-Sure High-Solids enamel paints form
Test Run #1, 43 So-Sure paint cans from Test Run #2, and 13 Eco-Sure High-Solids
enamel paints from Test Run #3. Eco-Sure High-Solids enamel paint cans
from Test Run #1 contained less than 15% material prior to puncturing
(estimated based on pre-treatment weight) and were collected over the
course of two years after discard. The nature of the So-Sure paint cans
selected was described above. Eco-Sure High-Solids enamel paint cans selected
from Test Run #3 also contained less than 15% material prior to puncturing
(estimated based on pre-treatment weight). However, these cans were only
collected over the course of one month after discard. PWC personnel segregated
and collected the cans for Test Run #3 from cans that were recently relinquished
because they had previously run out of Eco-Sure High-Solids enamel paint
cans that they deemed appropriate for evaluation. In addition, three basic
differences exist between the Eco-Sure High-Solids enamel paints and the
So-Sure paints:
- Eco-Sure High-Solids enamel paints are military
specification paints made specifically for the military. Commercial
users are unable to obtain high solids content paints of this nature;
- Eco-Sure High-Solids paint cans are lined with
a protective internal coating. This coating was removed during the can
cleaning process because paint stripper was used to remove the polymerized
solids adhered to the protective coating. Therefore, the weight of the
protective coating, which should be added to the tare weight of the
can, is lost in the calculation;
- Eco-Sure High-Solids enamel paints have two
shaker balls per can as opposed to one in most cans. Two balls may be
used to ensure proper dissolution of the additional solids present in
the can.
Tare weight determination procedures were outlined and agreed upon by
DTSC, Katec, and PWC, Appendix IV. Tare weight results supported the conclusions
established in the first tare weight evaluation of So-Sure paint cans,
Appendix V:
- 88% of the cans were emptied by the Aerosolv®
technology to less than 1.5% of their original capacity;
- Only one can exhibited a post-treatment residual
volume greater than 2.5% ;
- All of the cans exhibited post-treatment residual
volumes less than 3.0%
- Can number 273, the can with the highest post-treatment
weight also had the highest tare weight: 116.83 grams;
- Can number 750, the can with the second highest
residual volume (2.34%) had one of the lowest post-treatment weights:
103.91 grams;
- Can number 992, the can with the second highest
post-treatment weight (113.23) had one of the lowest residual volumes:
(0.47%).
In evaluating the military specification Eco-Sure High-Solids
enamel paints, it was reasonable to suspect that the residual volume would
be greater than that for the commercially common So-Sure paints. Katec
and PWC questioned the validity of evaluating a product whose use is primarily
limited to military applications. However, the parties agreed that utilizing
data obtained from tests performed on these cans would provide valuable
insight as to the capabilities of the Aerosolv® technology.
Katec and PWC also suspected (as discussed above) that cans of high-solids
paints that were stored in a near-empty capacity for sustained periods
of time would polymerize internally. In this case, one could not re-suspend
the solids and they would be unavailable for application as a coating.
Consequently, they would also be unavailable for discharge during aerosol
can puncturing and draining. Therefore, these cans would retain a greater
volume of residual than cans whose solids that did not have an opportunity
to polymerize internally. Katec and PWC hypothesized that aerosol cans
were not completely impervious to air and that oxidation and polymerization
took place inside the cans. If this theory were valid, the residual results
for Eco-Sure High-Solids enamel paint cans from Test Run #1 would be drastically
different than those from Test Run #3. DTSC and PWC representatives witnessed
part of this phenomenon when they investigated Eco-Sure High-Solids enamel
paint cans immediately after puncturing and discovered that the cans had
in fact allowed polymerized solids to adhere to the sides of the cans.
PWC representatives noticed the phenomenon to a greater extent when comparing
the amount of polymerization found in Test Run #1 cans to the lesser volume
found in Test Run #3 cans. Evaluation of the tare weight results further
highlighted the effect:
- All 13 cans from Test Run #3 exhibited tare
weight residual volumes between 0.8% and 3% with an average around 1.5%;
- Cans with higher post-treatment weights demonstrated
lower residual volumes (compare cans #10, #97, #122, and #132 to cans
#44, and #45).
- Five cans from Test Run #1 exhibited post-treatment
residual volumes in excess of 3%. Two of these cans appeared to be missing
a shaker ball and their tare weight results are suspect.
- The 14 cans remaining had tare weight results
between 0.8% and 3.0% with an average around 2.0%;
- Cans from Test Run #1 had noticeably more polymerized
solids adhered to the internal protective coating and the outside of
the tube.
All of the Eco-Sure High-Solids enamel paint cans were emptied to the
maximum extent practical; however, it was apparent that the Test Run #1
cans retained more residual volume than the Test Run #3 cans. Additionally,
Test Run #1 cans were noticeably more difficult to clean than either Test
Run #2 or Test Run #3 cans. Based on these observations, and in light
of the fact that DTSC and PWC representatives witnessed polymerized solids
adhered to the side of cans that were cut open immediately after puncture,
PWC concluded that polymerization does indeed occur in aerosol cans during
sustained storage.
Corrosion Preventative Compound
First Evaluation: For purposes of the first tare
weight determination, PWC randomly selected 75 cans from one kind of CPC
(Mil-C-81309E, Type III, Class 134A) to ensure the integrity of the tare
weight results. This particular type of CPC is a military specification
product containing chlorofluorocarbons (CFCs) that have been otherwise
banned from commercial use.
Tare weight results indicated that percent residual volumes consistently
ranged between 0.3% and 0.6% regardless of post-treatment weight. These
data further support the data trends discussed with regards to paint cans.
In this case, the type of material and the original total capacity of
the can remained constant. Therefore, the only variable was the effect
of the technology. From the results, PWC concluded that the technology
consistently empties cans with liquid-only components to less than 1%
residual.
Second Evaluation: Five types of CPC were evaluated
during the Field Test Demonstration: Mil-C-81309D, Type II, Class 2; Mil-C-81309E,
Type II, Class 134A; Mil-C-85054A, Type I, Class A; Mil-C-85054B(AS),
Type I, Class 134A; and Mil-C-81309E, Type III, Class 134A. From these
types DTSC selected 20, 18, 16, 5, and 15 cans respectively. Mil-C-85054B(AS),
Type I, Class 134A and Mil-C-8504A(A3), Type I, Class A contained barium
sulfate and were expected to demonstrate much greater residual volumes
than the other types. All of the CPC types are military specification
materials and contain CFC propellants. Materials with CFC propellants
are no longer manufactured for applications outside of military applications.
As such, the CPC products selected do not represent common commercial
use. However, the selection of these products for the Field Test
Demonstration assisted the research team in evaluating the effectiveness
of the carbon filter and potential occupational health exposure.
Tare weight results indicated that CPC cans that did not contain barium
exhibited residual volumes between 0.2% and 1.2%. These results were consistent
with the results obtained in the first tare weight determination. CPC
cans that contained barium exhibited residual volumes between 0.5% and
2.0%. These results were also consistent with expected results.
Brakleen
PWC randomly selected 75 cans of Brakleen, cleaned the cans with a naphtha
solvent, allowed the cans to dry, recorded the tare weight results of
each can, and determined the percent residual volume of each can. Tare
weight results indicated that percent residual volumes consistently ranged
between 0.3 and 0.5% regardless of post-treatment weight. These results
paralleled the CPC results with one exception: more Brakleen cans demonstrated
percent residual volumes around 0.3%.
Conclusions:
Based on the demonstration results, the Aerosolv® technology
has successfully demonstrated that it facilitates the emptying of aerosol
cans to less than 3% residual as defined by this objective.
The design of the Aerosolv® technology facilitates discharge
of in excess of 97% by weight of the capacity of aerosol cans processed.
The actual percentage of residual remaining in the can is a function of
the technology and the can design. In this Field Test, three types of
products were evaluated. For each type of product, the volume of liquid
captured in the lip of the can was similar, approximately 0.5 cubic centimeters.
However, the average percentage of residual remaining in the can for Brakleen®
was less than that for CPC, which was less than that for paint. Ironically,
the total original capacity by weight for Brakleen® exceeds
that for CPC by over 100 grams. The original capacity by weight for CPC
exceeds that for paint by over 150 grams on average. Because the paint
total capacity is significantly less than the CPC or the Brakleen®
, the percent residual by weight remaining in the paint cans is greater
(see discussion in the conclusion for Objective 1c below). However, in
every case, the weight captured in the lip of the can is minimal and for
98.6% of the cans evaluated, the residual volume constitutes less than
3% of the total original capacity.
Of further interest, five of the 375 cans evaluated during this tare
weight determination process that exhibited residual volumes greater than
3%, contained non-hazardous residuals that were present in a non-hazardous
form prior to puncturing. All five cans were military specification
Eco-Sure High-Solids enamel paint and all five were stored for up to two
years in a near-empty capacity. In addition, the residual volume calculation
for two of the five cans was suspect.
Objective 1b: Removal of Hazardous Waste to the Maximum Extent
Practical
The Aerosolv® puncturing/draining device is designed to
receive inverted aerosol cans. This design promotes drainage of the contents
of the can into the collection receptacle and coalescing filter as appropriate.
The puncturing pin places a hole just above the lip of the can through
which the contents are allowed to escape. The evacuation process is quick
and efficient. Cans are depressurized and emptied to the levels represented
in Objective 1a. Investigation of the processed cans allows one to quickly
determine that the cans are emptied to the maximum extent practical. See
Appendix XII for more detail.
Conclusions:
Based on the demonstration results, the Aerosolv® technology
has successfully demonstrated that it removes the contents of aerosol
cans to the maximum extent practical.
Objective 1c: Removal Efficiency
The Field Test Plan was developed to ensure that the results obtained
during the Field Test met the 90% confidence limit of the mean removal
efficiency. Data from each aerosol can product class was obtained from
the processing of the 375 cans described in the discussion for Objective
1a. The tare weight of each can was subtracted from the pre-treatment
weight of each can to determine the weight of material contained in each
can prior to processing (original content weight). The tare weight of
each can was then subtracted from the post-treatment weight of each can
to determine the weight of material that was not removed from the cans
(residual weight). The resulting residual weight was then subtracted from
the original content weight to determine the weight of material actually
removed (removal weight). The removal weight was then divided by the original
content weight and the result was multiplied by 100% to determine a removal
efficiency.
Conclusions:
Field test results indicate that the removal efficiency objective is
not a valid objective for purposes of this demonstration. Removal results
indicated that 95% of the materials contained in the cans were removed.
Corresponding removal efficiency results indicate a removal efficiency
of 75%. There is no obvious correlation between removal efficiency and
the Aerosolv® Technology's performance. As noted in the
conclusion for Objective 1a, the minimal volume of residue remaining in
each of the cans after processing was the same despite the volume of material
residing in the can prior to processing. For example, a full can containing
400 grams of original content material was emptied such that only 2 grams
of residual remained in the can. The removal efficiency for this can is
99.5%. Conversely, a 3% full can containing 12 grams of original content
material was also emptied such that only 2 grams of residue remained.
However, the removal efficiency for this can is only 16.6%. In both cases,
the cans were emptied to the maximum extent practical and to 0.5% of the
original full capacity of the respective cans by weight.
Objective 2a: Determine the Percent of Gaseous and Liquid Contents
Removed from the Processed Cans that is Captured by the Aerosolv®
Technology.
DTSC, Katec, and PWC developed a mass balance equation that compares
the sum of all of the aerosol can contents removed to the total weight
added to the Katec system. The sum of all contents removed was determined
by subtracting the sum of all post-treatment weights from the sum of all
pre-treatment weights per test run. The total weight added to the Katec
system was determined by subtracting the sum of all pre-treatment weights
from the sum of all post-treatment weights per component assembly. To
ensure accuracy and precision, a 200-kilogram capacity drum scale, accurate
to within +/- 0.1 kilogram and a laboratory balance accurate to within
+/- 0.01 grams were used. Further, to determine system capture efficiency
to the desired accuracy, approximately 45 pounds were collected by the
Aerosolv® collection system.
The greatest challenge DTSC and PWC faced with this approach was volatilization.
Because most aerosol components are extremely volatile, DTSC and PWC representatives
observed weight losses of 0.1 to 0.3 pounds per day from the collection
receptacle and the carbon filter unit. To offset these losses, weighing
procedures were modified to include record keeping at periodic intervals
not less than once per day. However, they could not account for immediate
losses.
The detailed calculations of the total mass discharged per can for each
Test Run are included as Appendix VI. Total mass discharge results are
presented in Appendix VII. Mass capture results reflecting the total mass
captured by the Aerosolv® recycling technology for each
Test Run are provided in Appendix VIII. PWC calculated the total mass
of material discharged from each can per test run from Appendix VII. PWC
then calculated the total mass of material captured in the Aerosolv®
recycling technology collection system from Appendix VIII. The total mass
of material captured was then subtracted from the total mass of material
discharged. The resultant mass was then divided by the total mass of material
discharged to obtain a percent variance. The variance was subtracted from
100% to obtain a percent capture, Appendix IX.
Conclusions:
The Aerosolv® technology effectively captured 95% of the
contents of the aerosol cans processed. As such, the Aerosolv®
technology has successfully demonstrated that it captures greater than
90% of the gaseous and liquid contents from the processed cans.
Objective 3a: Determine the total mass of the contents of aerosol
cans processed by the Aerosolv® technology resulting in
carbon filter breakthrough emissions and the mass resulting in carbon
filter changeout in accordance with criteria established in the Field
Test Plan
For each type of material an analysis was conducted to calculate the
cumulative number of grams discharged when the carbon filter exhaust monitor
reached 100,000 ppm. The detailed calculations are included as Appendix
X. The total mass collected per carbon bed filter is included as Appendix
XI. Not surprisingly, the values varied depending on the material. For
the five filters utilized during the paint processing, the filters emitted
100,000 ppm at an average of 16,800 grams of paint discharged. For CPC,
42,000 grams was discharged prior to the first filter emitting 100,000
ppm. The 100,000 ppm threshold was not reached on the second CPC filter
after 35,000 grams was discharged. The filter for the Brakleen®
never reached the 100,000 ppm threshold even though 46,000 grams was discharged
through the unit. In fact, the Brakleen® filter never exceeded
an exhaust emissions reading in excess of 3.88 ppm. The significance of
these findings is as follows:
- The filter effectively adsorbs target compounds. The Brakleen®
test runs were designed to test the effectiveness of the carbon bed
filters on products that were solely or primarily comprised of target
compounds. Perchloroethylene was selected because it is widely recognized
as one of the most common carcinogens in use today. Perchloroethylene
has an extremely low PEL and low RELs. The carbon bed filters associated
with the Brakleen® cans demonstrated no breach of integrity
after 46,418.02 grams of Brakleen® were discharged.
- For paint, which is comprised primarily of non-target compounds (containing
approximately 1% of target compounds on average), the carbon filters
emitted 100,000 ppm when approximately 16,800 grams were discharged.
No target compounds were detected. The carbon bed filter results associated
with the processed paint cans support the conclusion that the emissions
detected at the 100,000 ppm threshold are propellants (LPG's: propane;
butanes; dimethyl ether). The results are also in agreement with the
anticipated performance of the coconut carbon. Specifically, coconut
carbon has a lower affinity for LPG propellants (0.3% by weight) and
target compounds will displace LPGs. Therefore, the carbon bed filters
associated with the processed paint cans were still effective after
processing 16,800 grams of paint.
- For CPC, which is comprised of about 40% target compounds, the carbon
filter emitted 100,000 ppm when 42,000 grams were discharged for one
filter and never reached the 100,000 ppm threshold when 35,000 grams
were discharged on the second. In both cases, monitoring results indicate
that these emissions did not contribute to the employee's overall exposure
burden. Further, no target compounds were found at laboratory reporting
limits. As such, the monitoring results support the conclusion that
employees were not exposed above OSHA PELs, ACGIH RELs, or NIOSH RELs.
Refer to Appendix I, Section 3, Carbon Bed Area Samples, of the Report
for more details.
- There is no obvious or direct correlation of mass discharge and filter
saturation. The carbon bed filters associated with each of the test
runs did not reach saturation and can continue to be used effectively.
The 100,000 ppm threshold selected for purposes of this Field Test Demonstration
is an extremely conservative threshold that is more than adequately
protective of human health and the environment.
Conclusion:
A more appropriate basis for determining carbon change-out is when emissions
of target compounds from the carbon bed exhaust are detected in the breathing
zone at concentrations exceeding OSHA PELs. As stated previously, this
action point for carbon changeout was never reached during the field test.
Based on Field Test results noted above, PWC recommends that carbon changeout
occur after continuous or sustained processing well in excess of 2,000
cans (see Appendix XIII).
Desorption Factor
A situation that complicates fully resolving this objective is that organic
vapors desorb significantly off the carbon bed when not in use. This is
supported by emissions activity measured by the exhaust TVA for each carbon
bed prior to resuming can processing. The details of this desorption activity
are summarized in the Workplace Monitoring Report. In general, exhaust
TVA readings were always higher from a used carbon bed after the bed sat
undisturbed. The most significant variances were associated with cans
containing less than 40 grams of product prior to introduction into the
Aerosolv® technology. The desorption data reported below
is excised from Workplace Monitoring Report Chart #6.
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