v>EPA
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
EPA-600 2-80-145
June 1980
Research and Development
Demonstration of
Carbon Adsorption
Technology for
Petroleum Dry
Cleaning Plants
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution-sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-80-145
June 1980
DEMONSTRATION OF CARBON
ADSORPTION TECHNOLOGY FOR
PETROLEUM DRY CLEANING PLANTS
by
S. J. Lutz, S. W. Mulligan, and A. B. Nunn
TRW, Inc. Environmental Engineering Division
P. 0. Box 13000
Research Triangle Park, North Carolina 27709
Contract No. 68-03-2560
Project Officer
Ronald J. Turner
Industrial Pollution Control Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory, U. S. Environmental Protection Agency, and approved for publica-
tion. Approval does not signify that the contents necessarily reflect the
views and policies of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or re-
commendation for use.
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FOREWORD
When energy and material resources are extracted, processed, converted,
and used, the related pollutional impacts on our environment and even on our
health often require that new and increasingly more efficient pollution con-
trol methods be used. The Industrial Environmental Research Laboratory -
Cincinnati (lERL-Ci) assists in developing and demonstrating new and improved
methodologies that will meet these needs both efficiently and .economically.
This study was undertaken to demonstrate the technical feasibility of
applying carbon adsorption technology to control petroleum solvent vapors
emitted from the dryer exhaust of an industrial dry cleaning establishment.
In addition to reducing dryer emissions by 95 per cent, the activated-carbon
adsorption system was effective in recovering valuable solvents which .other-
wise would be emitted to the atmosphere.
This information will be of value both to the EPA's regulatory program
(Office of Air Quality Planning and Standards) and to the industry itself.
For further information concerning this subject, the Industrial Pollu-
tion Control Division should be contacted.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
m
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ABSTRACT
A carbon adsorption system was designed and installed on the exhaust
outlet from a dryer at an industrial dry cleaning plant utilizing Stoddard
solvent for cleaning purposes. Selected design and operating parameters
were varied to determine their effect on annualized operating costs and
system performance. After optimization, the carbon adsorber acheived a
demonstrated efficiency in reducing hydrocarbon emissions of 95 percent.
Annualized operating costs were determined to be $27,000, with a result-
ing cost effectiveness of $560/megagram ($510/ton).
This report was submitted in fulfillment of Contract No. 68-03-2560,
Task No. T5005 by the Environmental Engineering Division of TRW, Inc.,
under the sponsorship of the Industrial Environmental Research Laboratory
of the U.S. Environmental Protection Agency. This report covers a period
from October 1977 to April 1979, and work was completed as of April 1979.
IV
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CONTENTS
Foreword iii
Abstract iv
Figures vi
Tables vii
Abbreviations and Symbols ix
Acknowledgement x
1. Executive Summary 1
2. Program Description 3
3. Process Description 8
4. Test Methods 13
5. Results and Conclusions 23
6. Test Data • 48
7. Error Analysis 75
References 79
Appendix
A. Sample calculation to determine maximum expected error band
in the inlet mass rate of hydrocarbons 80
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FIGURES
Number Page
2-1 Physical layout carbon adsorption system 6
3-1 Dry cleaning equipment containing solvent 9
3-2 Operating procedure 10
3-3 Block diagram of carbon adsorption system 12
5-1 Breakthrough test: Cummulative inlet and outlet measurements. . 28
5-2 Emission reduction efficiency versus dryer utilization 29
5-3 Effect of dryer utilization on annualized operating costs. ... 44
5-4 Effect of dryer utilization on cost effectiveness 45
VI
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TABLES
Number Page
4-1 Pre-optimization Program Sampling Positions and Frequencies
of Sampling 16
4-2 Optimization Program Sampling Positions and Frequencies of
Sampling . 20
ii
5-1 Capital Costs for the Non-optimized Carbon Adsorption System . . 37
5-2 Annualized Operating Costs of Non-optimized Carbon Adsorption
System 39
5-3 Capital Costs for the Optimized Carbon Adsorption System .... 41
5-4 Annualized Operating Costs of Optimized Carbon Adsorption System
(51% utilization) 42
5-5 Annualized Operating Costs of Optimized Carbon Adsorption System
(25% utilization) . 46
5-6 Annualized Operating Costs of Optimized Carbon Adsorption System
(100% utilization) 47
6-1 Summary of Dry Cleaning Carbon Adsorption Demonstration Program
Operating Data (Metric units) 49
6-2 Summary of Dry Cleaning Carbon Adsorption Demonstration Program
Operating Data (English units) 51
6-3 Demonstration Program - Continuous Data Summary 53
6-4 Demonstration Program - Weekly Utilities 54
6-5 Comparison of Process Solvent and Recovered Solvent Properties . 55
6-6 Typical Analysis of Stoddard Solvent 56
6-7 Demonstration Program - Operating Labor 57
6-8 Optimization Program - Operating Labor 58
6-9 Optimization Program - Task 2 Blower Cycle Alteration
Electricity Consumption 58
vii
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Number Page
6-10 Optimization Program - Task 3 Adsorption/Desorption Cycle
Alteration .......................... 59
6-11 Optimization Program Adsorber Efficiency Data - Task 3 -
Adsorption/Desorption Cycle Alteration ............ 60
6-12 Optimization Program - Breakthrough Analysis Results ...... 60
6-13 Optimization Program Adsorber Efficiency Data - Task 5 -
Desorption Alteration ..................... 62
6-14 Optimization Program -. Task 5 - Desorption Alteration ...... 63
6-15 Optimization Program - Task 6 - Air Cooler Reduction Test. ... 64
6-16 Summary of Dry Cleaning Carbon Adsorption Optimization Program
Operating Data (Metric units) ................. 65
6-17 Summary of Dry Cleaning Carbon Adsorption Optimization Program
Operating Data (English units) ................ 67
6-18 Optimization Program - Tasks 2 & 3 - Adsorber Efficiency data. . 69
6-19 Optimization Program - Weekly Utilities Consumption ....... 70
6-20 Optimization Program - Comparison of Process Solvent and
Recovered Solvent Properties ................. 71
6-21 Demonstration Program - Carbon Test Results ........... 73
6-22 Weight Loss Versus Solvent Inlet Measurements .......... 74
7-1 Component Errors Comprising Each Process Operating Parameter . . 76
7-2 Maximum Expected Error for Each Process Operating Parameter. . . 77
vm
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LIST OF ABBREVIATIONS AND SYMBOLS
ABBREVIATIONS
ASTM
Btu
°C
cm
EP
EPA
UF
FID
f.s.
ft2
ft
ft3
gal
h
HC
hp
IBP
IERL
IFI
III
in
J
kg
kWh
1
American Society for
Testing and Materials
British thermal unit
degrees Celsius
centimeter
end point
Environmental Protection
Agency
degrees Fahrenheit
flame ionization detector
full scale
foot
square foot
cubic foot
gallon
hour
hydrocarbon
horsepower
initial boiling point
Industrial Environmental
Research Laboratory
International Fabricare
Institute
Institute of Industrial
Launderers
inch
joule
kilogram
kilowatt-hour
liter
ix
m
m2 -
n,3 -
mg
Mg
min
MTZ
MW
OSHA —
ppm
psig —
scfm
sec
TFE
VOC
yr
SYMBOLS
Br
C12 -
C13 -
C14 -
C15 -
C16 -
C17 -
C3H8 --
meter
square meter
cubic meter
mi 11 i gram
megagram
minute
mass transfer zone
megawatt
Occupational Safety and
Health Administration
parts per million
pounds per square inch
(gauge)
standard cubic feet per
minute
second
TFE Teflon
volatile organic compound
year
bromine
carbon 12 fraction
carbon 13 fraction
carbon 14 fraction
carbon 15 fraction
carbon 16 fraction
carbon 17 fraction
propane
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ACKNOWLEDGMENTS
The cooperation of Valley Industrial Services of Anaheim, California,
Mr. George Butcher, Vice President of Operations and Mr. Dennis E. Leo,
Vice President-General Manager, is gratefully acknowledged. Their partic-
ipation by providing a host site and their support contributed greatly to
the success of this demonstration project.
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SECTION 1
EXECUTIVE SUMMARY
The Environmental Protection Agency (EPAMs investigating the
feasibility of establishing emission standards for volatile organic
compounds (VOC) from petroleum solvent dry cleaning establishments.
Emission control technologies for these sources had not been successfully
demonstrated in this country. Because of EPA and industry concerns, a
program was developed to determine the effectiveness of carbon adsorption
in controlling VOC emissions. This consisted of fitting a prototype
carbon adsorption unit to the dryer exhaust of an industrial dry cleaner
(petroleum solvent); operating the system to collect performance data;
and evaluating the economics of operation at this establishment.
TRW Environmental Engineering Division, under contract to EPA-IERL,
provided all necessary services to specify, procure, install, test, and
evaluate the demonstration carbon adsorption unit. Valley Industrial
Services of Anaheim, California, was selected as the host site, and
carbon adsorbers were purchased from VIC Manufacturing Company of
Minneapolis, Minnesota.
The carbon adsorber system was initially operated in strict compliance ,
with the recommendations and instructions of the adsorber manufacturer
and his field representatives. Early in this test period, it became
apparent that the adsorption system had been overdesigned, resulting in
removal efficiencies far in excess of the specified performance guarantee
of 90 percent solvent removal on a 24-h average. The test program was,
therefore, amended to include an evaluation of changes to the design and
operating procedures for the carbon adsorption system. Various design
parameters were modified to determine their effect on the performance
and cost of the adsorption system. From these studies, an optimized
system was established for use in evaluating the performance, cost, and
cost effectiveness of utilizing carbon adsorption technology for the
reduction of VOC emissions from petroleum dry cleaning plants.
The host dry cleaning plant is a large, industrial facility utilizing
a 180 kg (400 Ib) dryer to process approximately 1588 kg (3500 Ib) of
articles per day. This throughput represents about 50 percent of the
8-h capacity of the dry cleaning dryer. Underutilization of this nature
is commonplace in the industry. Data were, therefore, developed using
the test program to determine the effect of the different utilization
rates on the various parameters under evaluation.
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The hydrocarbon emission reduction efficiency for the optimized
design (applied to the dryer exhaust) was 95 percent, and varied from 93
percent for a plant with 100 percent utilization to 97 percent at 25
percent utilization. Capital costs for this system, including site
preparation and equipment installation, are estimated at $128,000 (mid-
1978 dollars). Cost effectiveness, defined as the annual operating cost
divided by the quantity of emission reduction, is a function of equip-
ment utilization rates, and additionally exhibits a strong dependence on
the market value of the recovered solvent. A value of $0.16/1 ($0.61/gal)
was assumed for the basic analysis, but the effect of increases in
petroleum costs on annualized operating costs was investigated. The
cost effectiveness of the optimized design was $560/Mg ($510/ton), and
was estimated as $1,090/Mg ($980/ton) and $220/Mg ($200/ton) for 25
percent and 100 percent utilization, respectively. When the value of
Stoddard solvent reaches $0.60/1 ($2.30/gal), the optimized system (50
percent utilization) will have zero annual operating costs, neglecting
the rise in other operating expenses.
The results of this project demonstrate the technical feasibility
of applying carbon adsorption technology to reduce the emission of
hydrocarbon solvents from the dryer exhausts at petroleum solvent dry
cleaning plants. The cost effectiveness of this technique, $560/Mg
($510/ton), is expected to drop significantly as the value of the
reclaimed solvent, a petroleum distillate, increases. Even at the
present cost effectiveness, carbon adsorption is economically comparable
with the cost of emission reduction required in other industries. An
additional benefit, provided by the application of carbon adsorption
technology to the petroleum dry cleaning industry, is the reduction in
overall consumption of petroleum products by these plants. The demonstration
plant recovered solvent at a rate of 61,000 1 (16,000 gal) per year
which otherwise would have to be replaced with new solvent purchases.
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SECTION 2
PROGRAM DESCRIPTION
The purpose of this program was to conduct a field demonstration of
the technical feasibility and effectiveness of carbon adsorption in
reducing hydrocarbon emissions from dry cleaning plants using petroleum
solvents. Its scope included the selection of a host site for the field
demonstration; the selection, installation, and start-up of the emission
control system; a period of operation during which the system was evalua-
ted in the configuration specified by its manufacturer; and a period of
operation during which the effects of several modifications to the
system configuration were evaluated.
SITE SELECTION
A host site was sought at an industrial petroleum dry cleaning
facility which could provide an exhaust gas stream from a 180 kg (400
Ib) dryer of 3.7 nT/sec (at 0°C) (8,400 scfm) with up to 10,000 ppm of
solvent (measured as propane).
Because of the large number of potential sites in the country, two
industry trade associations (Institute of Industrial Launderers (III)
and International Fabricare Institute (IFI)) were consulted in the
selection of candidate establishments. In mid-November 1977, TRW met
with members of III, IFI, the Office of Air Quality Planning and Standards
(OAQPS) and the Industrial Environmental Research Laboratory (IERL) of
the Environmental Protection Agency (EPA). The purpose of this meeting
was the discussion of candidate sites and selection criteria along with
other aspects of the task. The decision was made to perform the demon-
stration test in Southern California. Because of the mild weather in
this area, the demonstration unit could be installed out-of-doors, thus
eliminating the need for plant floor space and the requirement of pro-
tecting the equipment from inclement weather. The decision to use the
exhaust from a 180 kg (400 Ib) dryer was made with the knowledge that
large industrial dry cleaners use this machine size and on the assumption
that the test results could be scaled down to lesser capacity dryers.
Based on these ground rules, the Institute of Industrial Launderers
supplied a list of eight candidate sites. Early in December 1977, TRW
along with IERL and IIL made a preliminary visit to these locations,
using the following screening criteria:
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1. Availability of space for the demo unit and instrument
trailer.
2. Location of the dryer in relation to demo unit space;
e.g., a dryer in the center of a plant precludes its
use since the exhaust ducting run would be excessive.
3. The attitude of the operator, including technical
qualifications and housekeeping.
4. The availability of a steam source, i.e., 0.4 MW (40
boiler horsepower) is required. Other utilities are not
constraining.
5. The type and condition of the dryer.
6. The products of the facility.
7. Proximity to TRWs Redondo Beach facility to minimize
travel costs.
Photographs of each candidate site were made to document general layouts.
In mid-December 1977, the working group again met to present the
general status of the task. At this time, the candidate site list was
reduced to four, based on the screening process. From the four, Valley
Industrial Services of Anaheim was chosen as the host site for the
demonstration project for the following reasons:
1. The demonstration unit and instrument trailer could be
located in the parking lot of the plant, near the exhaust
duct of the dryer;
2. Valley's operating procedures and housekeeping are excellent;
3. The dryer used at Valley is typical for a large industrial
petroleum dry cleaning establishment; and
4. Valley is within one hour's drive of TRW's Redondo Beach
complex.
SITE DEVELOPMENT
A survey of domestic manufacturers of commercially available carbon
adsorption units resulted in the identification of five potential
suppliers who could provide systems for this application. Pertinent
specifications for the carbon adsorption system were:
4
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1. Inlet concentration <10,000 ppm (measured as propane).
2. Inlet temperature <77°C (170°F) at dryer exit.
3. Inlet flow <3.7 m3/sec at 0°C (8,400 scfm).
4. Exhaust concentration <1,000 ppm (measured as propane).
5. Adsorbers capable of having carbon samples
removed and the carbon bed changed without major
disassembly.
6. Equipment must conform to all health and safety
requirements of NFPA, local fire codes, all local
regulations, and applicable OSHA guidelines.
The potential suppliers were asked to quote on this carbon adsorption
system. Two quotations were received and reviewed for technical accep-
tance. Both were found to demonstrate the necessary technical and
production capabilities to deliver the system in conformance with the
design specifications. VIC Manufacturing Company was chosen as the
equipment supplier on the basis of cost and delivery.
Three installation contractors who have had experience with carbon
adsorption systems were contacted to provide quotations for the instal-
lation of the emissions control system, including ancillary equipment such
as a boiler and cooling tower. A personal visit was made to each of
these organizations to hold a detailed technical review meeting. This
was done to ensure each contractor's understanding of the technical
specifications required. Bids were evaluated on the basis of cost,
related experience, and ability to complete the installation in the
scheduled time frame. The Sam Gerber Company of Los Angeles was selected
as the installation contractor.
The engineering design of the exhaust gas transport system was
performed by TRW. TRW provided additional field supervision for the
installation of all equipment and hardware. Figure 2-1 depicts the site
arrangement of the equipment for the demonstration program.
OPERATION AS DESIGNED
After initial start-up, the carbon adsorption system was operated
for 18 weeks, during which time all equipment was operated as specified
by VIC Manufacturing Company, the carbon adsorber manufacturer. Test
data were taken during this period to obtain operating data for an
"off-the-shelf" system.
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ALTERNATE
DRYER
CT>
.ATMOSPHERIC
DAMPER
PLANT ROOF
TRW TEST TRAILER
Figure 2-1. Physical layout carbon adsorption system.
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OPTIMIZATION STUDIES
During the initial phase of operation, it became apparent that the
carbon adsorption system was overdesigned with respect to the actual
requirements for this facility. This was determined when the time-
weighted concentration of solvent in the exhaust stream from the dryer
was measured to be 2,100 ppm (as propane), not 10,000 ppm as designed.
Also, the average exhaust gas flow rate to the adsorption system was
measured to be 20 percent less than the specified design flow rate of
3.7 m /sec (8,400 scfm). Consequently, six design parameters were
modified to determine their effect on the performance and cost of the
adsorption system. From these studies, an optimized system was estab-
lished for use in evaluating the performance, cost, and cost effectivness
of carbon adsorption for hydrocarbon emissions reduction from petroleum
dry cleaning plants. The six design modifications were as follows:
o The lint filter was modified to increase its surface area.
o The blower and adsorber controls were modified to allow
the blower to cycle on and off with the dryer instead of
operating continuously.
• The operation of the carbon adsorbers was modified by
1) operating with only two adsorbers; and 2) desorbing
each adsorber only once a day.
@ Carbon breakthrough tests were run to determine the
amount of excess carbon in the adsorbers.
9 The duration of the desorption cycle was altered to
determine the minimum desorption time necessary for
proper operation of the adsorption system.
• The cooling water flow to the air cooler was reduced
in steps until it was completely eliminated. This
study determined the minimum performance and size of
any air cooler required for temperature reduction.
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SECTION 3
PROCESS DESCRIPTION
VALLEY INDUSTRIAL SERVICES
Valley Industrial Services is a large industrial launderer and dry
cleaner, providing uniform services, shop towels, fender covers, dust
mops, and floor mats to establishments in the Los Angeles area. Valley
dry cleans approximately 450,000 kg (1,000,000 Ib) of soiled articles a
year; comprised of 85 percent uniform pants and 15 percent fender covers.
Valley's dry cleaning operation utilizes Stoddard solvent (a
petroleum-based solvent) as a cleaning agent. Figure 3-1 illustrates
the design and interconnection of the significant solvent-containing
equipment. The washer-extractor is a 230 kg (500 Ib) unit manufactured
by Washex. The cycle time for the washer-extractor is approximately 40
min, and Valley runs an average of seven loads per day. The dryer is a
180 kg(400 Ib) unit manufactured by Challenge-Cook. Valley Industrial
Services is currently operating the dryer with 110 kg (250 Ib) loads
which require a cycle time of approximately 20 min. In addition, Valley
has two solvent stills, each with a 1890 1 (500 gal) capacity, manufactured
by Washex.
Solvent is pumped from the underground solvent storage tank into
the washer. Water and other dry cleaning additives are automatically
metered into the washer during certain sequences of the washing cycle.
Solvent is discharged from the washer-extractor into a used solvent
holding tank. This' tank is provided to accumulate surges in the solvent
discharge rate, allowing the solvent stills to operate on a continuous
feed basis.- Distilled solvent is returned to the underground solvent
storage tank. Floor and equipment vents are provided to remove fugitive
solvent from the workplace and discharge it to the atmosphere. The
dryer is a non-recovery type which continuously vents the dryer exhaust
to the atmosphere.
Valley Industrial Services relies on manual techniques to load and
transfer articles to dry cleaning equipment. Figure 3-2 illustrates
this operation. Soiled articles are placed in a cart and weighed to
control each load at approximately 230 kg (500 Ib). This cart is then
pushed to the washer-extractor where its load is put into the machine.
At the conclusion of the extraction cycle, the clothes are then placed
into two carts, each containing equal weights. One cart is loaded into
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To Atmosphere
To Atmosphere
Floor and Equipment Vents
Used
Solvent
Holding
Tank
Solvent
Still
Underground Solvent Storage Tank
\
t
Figure 3-1. Dry cleaning equipment containing solvent.
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if
STEP 1
181 kg (400 Ib) of soiled
articles are loaded into
washer-extractor
STEP 2
Washed Articles are loaded
into 2 carts of 113 kg (250
Ib.)
STEP 3
Cart 1 is loaded into dryer.
Cart 2 is left in dry cleaning
area.
STEP 4
Load 1 is removed from dryer
and sent to finishing area.
Cart 2 is loaded into dryer.
STEP S
Load 2 is removed from dryer
and sent to finishing area.
Figure 3-2. Operating procedure.
10
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the dryer, while the second cart is left standing in the dry cleaning
area. At the conclusion of the drying cycle, the dryer is emptied and
the second cart is loaded into the dryer.
CARBON ADSORPTION SYSTEM
The carbon adsorption system connects with the existing plant
equipment where the dryer exhaust duct penetrates the plant roof. The
main components of the carbon adsorption system are depicted in Figure
3-3.
Original System Configuration
The exhaust gas from the dryer is first passed through a lint
filter which utilizes^a cotton filter bag with a surface area of approx-
imately 1.0 m2 (11 ft ). It is then passed through an air cooler which
is chilled with cooling water to reduce the exhaust gas stream tempera-
ture from 63°C (145°F) to approximately 38°C (100°F). A 0.5 MW (50 hp)
blower then forces the exhaust stream downward through the carbon canis-
ters. Three 2.4m (8 ft) diameter canisters are used, each containing
1800 kg (4000 Ib) of petroleum-based carbon. As supplied, the operation
of the unit is as follows: two tanks are in the adsorb mode whereby
they are connected to the outlet of the blower, while the third tank is
in a desorb mode. This arrangement lasts for approximately 1 hr, at
which time the tank which had been desorbing is brought back to an
adsorb mode and one of the tanks which had been adsorbing is desorbed
(this tank is the one which had been in the adsorb mode the longest).
This cycle is then repeated hourly.
During the desorption cycle, steam passes through the carbon bed in
an upward path. After leaving the adsorber, it is introduced into a
water-cooled condenser where the steam and stripped Stoddard solvent are
condensed and the two-phase liquid stream is collected in a decanter.
The organic and water phases are separated and individually drawn off.
The recovered solvent is directed to a holding tank, while the wastewater
stream is discarded into the city sewer system. Analysis of the waste-
water stream shows the solvent content to be less than 0.3 ppm.
Modified System Configuration
During the optimization studies, several modified system configu-
rations were studied, as outlined in Section 2. The final optimized
system configuration was similar to the original configuration, except
that only two adsorbers, which were desorbed only once each day, were
used and no air cooler was utilized.
11
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CLEANED EXHAUST
COOLING WATER
w
AIR
COOLER
BLOWER
.1
LINT
CONTROL
-MAKE-UP AIR
DRYER
RECOVERED
SOLVENT
HOLDING TANK
CARBON
ADSORPTION
UNIT
MSTE WATER TO SEWER
Figure 3-3. Block diagram of carbon adsorption system.
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SECTION 4
TEST METHODS
This chapter explains the test and calibration procedures used by
TRW during the carbon adsorption test program.
PRE-OPTIMIZATION TEST PROGRAM
Methods Summary
Hydrocarbon Concentration Determination--
Continuous sampling of the gas streams to and from the carbon
adsorption unit was accomplished using two Beckman 400 flame ionization
detectors (FID). Sample lines to both detectors were 1 cm (3/8")
Teflon (TFE), heated to 93°C (200°F) (using resistance heating) to
prevent sample degradation. A fine particle filtration system for each
sample line was used to prevent contamination of the FIDs. In addition,
an in-line condenser was used to remove water vapor from the sample gas
stream.
Combustion air for the two FIDs consisted of certified hydrocarbon-
free (<1.0 ppm) zero gas.
Calibration of the FIDs consisted of introducing the following
known concentration gases into the respective analyzers:
Inlet Outlet
zero gas (<1.0 ppm HC) zero gas (<1.0 ppm HC)
11,000 ppm C3Hg 1,060 ppm C3Hg
A dual-pen strip chart recorder was used to continuously record the
output of the FIDs during the working hours of the carbon adsorption
unit.
Exhaust Gas Flow Rate Determination—
The inlet gas stream flow rate was continuously monitored using a
hot-wire anemometer; the output of the anemometer was electronically
linearized to give a direct signal output corresponding to the gas
stream velocity.
13
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The relationship of this velocity to the average flow was deter-
mined by measuring the gas stream flow rate using EPA Method 2 (40 FR
23060, August 18, 1977), and comparing this to the average measured
velocity from the anemometer.
Temperature Measurements of Various Streams—
The temperatures of the various liquid and gas streams were moni-
tored continuously using J-type (iron-constantan) thermocouples.
Electricity Consumption--
Two kilowatt-hour meters were used to determine: (1) the total
electrical power usage of the carbon adsorption unit plus the instru-
ment trailer and (2) the electrical power consumption of just the
instrument trailer. Thus, by determining the difference between (1) and
(2), the electrical power usage of the carbon adsorption unit was determined.
Natural Gas Consumption—
A displacement gas totalizer was used to determine the natural gas
consumption rate.
Water Usage--
Five water meters were used to determine the following:
1. Water consumption of boiler.
2. Water makeup needs of cooling tower.
3. Rate of decanted water discharged to sewer system.
4. Cooling water demand of air cooler.
5. Cooling water demand of condenser.
Steam Flow Rate to Adsorption Unit--
Steam flow was measured continuously using a permanently installed
orifice meter.
Solvent Recovery Rate--
Recovered solvent was measured by collection in a holding tank and
using a calibrated tank gauge to determine the quantity of recovered
solvent.
Solvent Analysis-
Two composite solvent samples (one of recovered solvent and one of
solvent introduced into the dry cleaning process) were made up by com-
bining five equal-volume daily samples of the respective solvent into
two separate weekly samples and both were then analyzed for the following:
1. Composition using a gas chromatograph (results were reported as
percent C^s percent C]3, percent C]4 and Ci5, percent
and percent C-,y or greater).
14
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2. Flash point using ASTM test method D56, flash point by tag
closed tester.
3. Distillation range using ASTM test method D86, distillation
of petroleum solvents.
4. Kauri-Butanol value using ASTM test method D1133, Kauri-Butanol
value of hydrocarbon solvents.
5. Acidity using ASTM test method D1093, acidity of distillate
residues on hydrocarbon liquids.
6. Bromine number using ASTM test method D1159, bromine number
of petroleum distillates and commercial aliphatic olefins
by electrometric titration.
In addition, water concentrations in the recovered solvent were
determined on a daily basis using the Karl Fisher determination (ASTM
test method D1364, water in volatile solvents).
Solvent Concentration in Decanted Water and Bottom Drain--
A flow proportional weekly composite sample was made from the
decanter water outlet and the bottom drain from the carbon adsorption
unit. Solvent concentration of this sample was then determined by
extraction and subsequent analysis using flame ionization.
Analysis of Carbon in Bed-
Samples were taken from the top, middle, and bottom of a carbon bed
to determine carbon activity and retentivity. Carbon activity was
measured using perch!oroethylene adsorption at 21 °C (70°F), while carbon
retentivity was measured by air desorption at 21°C (70°F).
Sampling Positions and Frequencies of Sampling
The sampling positions for each parameter measured during the
carbon adsorption pre-optimization test and the frequencies of sampling
are given in Table 4-1.
OPTIMIZATION PROGRAM TEST PLAN
Evaluation Requirements
In order to determine the optimum operating design of the carbon
adsorption system, the following criteria were employed:
Task 1 - Change of filter system.
Extent to which operating labor can be reduced.
Task 2 - Blower cycle alteration.
Electricity savings induced by less than full-time operation
of the 0.5 MW (50 hp) blower.
15
-------
TABLE 4-1. PRE-OPTIMIZATION PROGRAM SAMPLING POSITIONS AND FREQUENCIES OF SAMPLING
Parameter to be
measured
Sampling location
Frequency
of sampling
1. Inlet solvent concentration
of exhaust gas
2. Outlet solvent concentration
of exhaust gas
3. Exhaust gas flow rate to
adsorber
4. Temperature of exhuast gas
to adsorber
5. Electrical consumption of
process
6. Natural gas consumption of
process
7. Steam flow rate to adsorber
8. Steam temperature at inlet
to adsorber
9. Water consumption of boiler
10. Steam temperature at outlet
of adsorber
11. Concentration of solvent in
water phase stream of decanter
Between air cooler and
carbon adsorption unit
Carbon adsorption unit
vent
Between air cooler and
carbon adsorption unit
Between air cooler and
carbon adsorption unit
Main power line and power
line to trailer
Gas line to boiler
Inlet to adsorber
Inlet to adsorber
Water line to boiler
Outlet of adsorber
Between decanter and
sewer entrance
(continued)
Continuous
Continuous
Every 2.5 min
Every 2.5 min
Kilowatt meter
Gas totalizer
Continuous
Every 2.5 min
Flow totalizer
Every 2.5 min
Weekly composite sample
-------
TABLE 4-1. (continued)
Parameter to be
measured
Sampling location
Frequency
of sampling
12. Quantity of recovered solvent
13. Quality of recovered solvent
14. Carbon analysis
15. Inlet cooling water tempera-
ture of air cooler
16. Outlet cooling water tempera-
ture of air cooler
17. Inlet cooling water tempera-
ture of condenser
18. Outlet cooling water tempera-
ture of condenser
19. Quantity of decanted water
20. Water consumption of air
cooler
21. Water consumption of condenser
22. Quality of raw solvent
Solvent holding tank
Solvent holding tank
Grab sample of carbon
out of tank
Before air cooler
After air cooler
Before condenser
After condenser
Waste line to sewer
Water line to air cooler
Water line to condenser
Solvent feed tank
Daily measurement
Weekly composite sample
Three times:
a. New carbon
b. Middle of test period
c. End of test period
Every 2.5 min
Every 2.5 min
Every 2.5 min
Every 2.5 min
Flow totalizer
Flow totalizer
Flow totalizer
Weekly composite sample
-------
Task 3 - Adsorption/desorption alteration.
Reduction in operating labor.
Reduction in capital costs.
Reduction in steam consumption rate.
Reduction in gas and electricity consumption rates.
Reduction in cooling water consumption rate.
Task 4 - Carbon bed depth adjustment.
Reduction in hydrocarbon emission rate.
Reduced design capital requirements.
Task 5 - Desorption alteration.
Effect on quality of recovered solvent.
Reduction in quantity of steam per quantity of recovered solvent.
Reduction in total steam consumption.
Task 6 - Air cooler reduction.
Change in inlet gas temperature to beds.
Reduced design capital requirements.
Reduced water demand.
Test Elements
\
Test Parameters--
To fulfill the objectives of the Optimization Program, the following
test parameters were monitored:
1. Solvent concentration of the inlet gas stream to the adsorber.
2. Solvent concentration of the outlet exhaust gas stream from
the adsorber.
3. Gas flow rate to the adsorber.
4. Temperature of gas to the adsorber.
5. Electrical consumption of the adsorption unit and the boiler.
6. Natural gas consumption of the boiler.
7. Steam flow rate to the adsorber.
8. Steam temperature to the adsorber.
9. Water consumption of the boiler.
10. Temperature of the desorb steam at carbon adsorber exit.
11. Temperature of bed during desorption.
12. Quantity of recovered solvent.
13. Analysis of recovered solvent for composition, flash point,
impurities, distillation range, and Kauri-Butanol value.
14. Concentration of solvent in carbon samples.
15. Temperature of supply water to air cooler.
16. Temperature of exit water from air cooler.
17. Temperature of supply water to condenser.
18. Temperature of exit water from condenser.
18
-------
19. TRW test operator's log, including number of dry cleaning
cycles and corresponding total operating time on daily basis.
20. Machine operator's log listing dry, extracted, and clean weights
of clothes.
21. Quantity of decanted water.
22. Water flow rate into air cooler.
23. Water flow rate into condenser.
Sampling Positions and Frequency—
Sampling positions for the various parameters to be measured as
well as sampling frequencies are given in Table 4-2.
Test Methods
All test methods listed in the pre-optimization test program were
used during the optimization test with one exception. A positive dis-
placement flow meter was installed in the solvent return line with a
measurement accuracy of +1 percent. This superseded the calibrated tank
gauge used in the pre-optimization study. No other measurement techniques
were changed.
19
-------
TABLE 4-2. OPTIMIZATION PROGRAM SAMPLING POSITIONS AND FREQUENCIES OF SAMPLING
Parameter to be
measured
Sampling location
Frequency
of sampling
PO
o
1. Inlet solvent concentration
of exhaust gas
2. Outlet solvent concentration
of exhaust gas
3. Exhaust gas flow rate to
adsorber
4. Temperature of exhaust gas
to adsorber
5. Electrical consumption of
process
6. Natural gas consumption of
process
7. Steam flow rate to adsorber
8. Steam temperature at inlet
to adsorber
9. Water consumption of boiler
10. Steam temperature at outlet
of adsorber
11. Carbon bed temperature
Between air cooler and
carbon adsorption unit
Carbon adsorption unit
vent
Between air cooler and
carbon adsorption unit
Between air cooler and
carbon adsorption unit
Main power line and power
line to trailer
Gas line to boiler
Inlet to adsorber
Inlet to adsorber
Water line to boiler
Outlet of adsorber
Bottom of carbon bed
Continuous
Continuous
Every 2.5 min
Every 2.5 min
Kilowatt meter
Gas totalizer
Continuous
Every 2.5 min
Flow totalizer
Every 2.5 min
Every 2.5 min
(continued)
-------
TABLE 4-2. (continued)
Parameter to be
measured
Sampling location
Frequency
of sampling
12. Quantity of recovered
solvent
13. Quality of recovered
solvent
14. Carbon analysis
15. Inlet cooling water tempera-
ture of air cooler
16. Outlet cooling water
temperature of air cooler
17. Inlet cooling water tempera-
ture of condenser
18. Outlet cooling water
temperature of condenser
19. Quantity, of decanted water
20. Water consumption of air
cooler
Solvent line to holding
tank
Solvent holding tank
Grab sample of carbon
out of tank
Before air cooler
After air cooler
Before condenser
After condenser
Waste line to sewer
Water line to air cooler
Flow totalizer
Three times
a. End of task 3
b. End of task 4
c. End of task 6
Two times
a. End of task 4
b. End of task 6
Every 2.5 min
Every 2.5 min
Every 2.5 min
Every 2.5 min
Flow totalizer
Flow totalizer
(continued)
-------
TABLE 4-2. (continued)
Parameter to be Frequency
measured Sampling location of sampling
t\3
21. Water consumption of Water line to condenser Flow totalizer
condenser
22. Quality of raw solvent Solvent feed tank Weekly composite sample
-------
SECTION 5
RESULTS AND CONCLUSIONS
SUMMARY OF RESULTS
The carbon adsorption system was initially designed to provide a
level of control in excess of that which was specified for the demon-
stration program. This occurred because of two factors. First, because
of the long lead time associated with the purchase and installation of
the carbon adsorbers9 specifications for the adsorption system were
prepared prior to the final selection of the host site. Valley Indus-
trial Services, the host site, has a dryer utilization of approximately
50 percent which results in a lower concentration of solvent in the
exhaust gas reaching the adsorbers than what was originally anticipated.
Second, Vic Manufacturing Company, the carbon adsorber supplier, re-
sponded to the specification requirement for a guaranteed 90 percent
removal efficiency by including a significant amount of excess capacity
to ensure that the carbon beds would not become overloaded.
This overdesign resulted in an emission control system which achieved
a reduction in hydrocarbon emissions, after system equilibration, of
98.8 +0.5/-0.7 percent based on a daily average. The cost effectiveness
of this design was $990/Mg ($900/ton).
A program was then initiated to modify the carbon adsorber system.
The goal of this modification was to optimize the design of the carbcn
adsorbers for the specific requirements of the host site. These modi-
fications included changes in both the size and complexity of the carbon
adsorbers to reduce the capital costs, and in the operating procedures
to reduce the operating costs.
The final optimized system produced a hydrocarbon emission reduction
of 94.8 +2.0/-3.2 percent based on a daily average. The cost effective-
ness of this design was $560/Mg ($510/ton).
The cost effectiveness figures presented above are highly dependent
on the value of the recovered solvent. Stoddard solvent is a petroleum
distillate and its value, therefore, rises proportionately with the cost
of petroleum. A value of $0.16/1 ($0.61/gal) was used to derive the
cost effectiveness of this emission control system. This value is
approximately equal to the cost of Stoddard to the host site in the fall
of 1978, the time of the testing. When the value of Stoddard solvent
23
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reaches $0.60/1 ($2.30/gal), the optimized system configuration will
have zero annual operating costs, neglecting the rise in other operating
expenses.
The cost effectiveness of the carbon adsorption system is also
highly dependent on the utilization rate of the dry cleaning dryer, the
principal source of solvent vapors. During the test program, Valley
Industrial Services operated the dryer under test at 51 percent of its
capacity, based on operations at the rated dryer load for an 8-h day,
5 days per week. Such underutilization appears to be commonplace in the
dry cleaning industry. Calculations were performed to determine the
cost effectiveness of the optimized carbon adsorption system resulting
from variations in this rate of dryer utilization. At a utilization
rate of 25 percent, the cost effectivness was $l,090/Mg ($980/ton), and
at a utilization rate of 100 percent, the cost effectiveness was $220/Mg
($200/ton), also based on the $0.16/1 ($0.61/gal) value for the recovered
solvent.
Confirmation of the emission reduction efficiency was attempted by
comparing the solvent mass flow rate out of the dryer with the quantity
of recovered solvent. This analysis technique produced an indicated
solvent recovery efficiency of 88.1 percent, but was subject to a consi-
derable experimental error of +23/-17 percent.
The recovered solvent was analyzed and compared with fresh solvent
for distillation range, acidity, Kauri-Butanol value, bromine number,
flash point, and solvent composition. In all cases, the recovered
solvent was found acceptable for reuse by the dry cleaning facility
without requiring any additional purification.
OPTIMIZATION STUDIES
The carbon adsorption system was evaluated during a series of
optimization studies from December 4, 1978, through March 23, 1979. The
following six studies were conducted during this period:
1) Filter modification.
2) Blower cycle alteration.
3) Adsorption/desorption cycle alteration.
4) Carbon bed depth adjustment.
5) Desorption alteration.
6) Air cooler reduction.
This section summarizes the results of these studies and the respective
effects on performance of the system.
Objectives
The objectives of each of the optimization studies are listed
below:
24
-------
1. Filter modification - The objective was to reduce the daily
labor requirements associated with filter changing and cleaning.
2. Blower cycle alteration - The objective was to reduce the
electricity consumption of the system.
3. Adsorption/desorption cycle alteration - The purpose was to
reduce design capital requirements and operating costs of the
system by removing one bed from operation and by operating the
boiler only at the end of the day.
4. Carbon bed adjustment - The goal was to determine if some
portion of the carbon could be removed from the beds in
use, thereby reducing the design capital requirements of the
system.
5. Desorption alteration - The purpose was to determine if opera-
ting costs could be. reduced by altering the desorption parameters.
6. Air cooler reduction - The purpose was to determine if design
capital requirements could be reduced by operating the system
without a cooling system in the ductwork leading from the
dryer to the carbon beds.
Results
This section describes .the results of these optimization studies
and also describes the "optimized system."
Filter Modification-- 2 2
The original 1.0 m (11 ft ) cotton filter bag and its housing in
the dryer exhaust ductwork were replaced with a 1.8 m2 (19 ft2) bag and
housing. The new filter could be operated for an entire operating day
without being changed. Approximately 30 min were required to change and
clean a filter bag. The original system required three changes daily.
The new filters, therefore, reduced the daily operating labor associated
with filter changing and cleaning from 1.5 h to 0.5 h.
Blower Cycle Alteration—
The adsorption system was modified in such a way as to allow the
0.5 MW (50 hp) booster fan to be activated and deactivated by the dryer
being tested, except when manually operating for desorption or other
reasons. Previously, the blower was turned on in the morning with the
rest of the system and off in the evening. It, therefore, ran continuously
all day, regardless of whether or not the dryer was in operation.
There was some concern that the electrical modifications would
actually result in an increase in electricity consumption due to the
power surge required to activate the large blower. This was proven to
be a false concern, however, since the modification resulted in a net
decrease in electricity costs by 10 percent.
25
-------
Adsorption/Desorption Cycle Alteration--
The adsorption system, as supplied by VIC Manufacturing, operated
automatically on schedule where two beds were absorbing while a third
was being desorbed. Every hour a cycle change occurred during which
adsorb mode and a bed on the adsorb was switched to desorption. The net
result of the cycle was that each bed was desorbed after 2 h of opera-
tion. This optimization test changed the operation to a schedule where
two beds were in the adsorb mode for the entire day and were each desorbed
for 1 h at the end of the day. The third carbon bed remained dormant
for the duration of the program.
An initial indication of the unacceptability of this mode of opera-
tion would be the attainment of breakthrough during daily operations and
a drastic decrease in adsorber efficiency. This phenomenon, which would
be determined when the concentration of solvent in the exhaust stream
began to rise dramatically from its normal "baseline" of 100 ppm, was
not observed. Therefore, the system can be operated in the described
manner making the third carbon bed unnecessary. For new systems, this
can result in a reduction in capital costs. As discussed in the Carbon
Bed Depth Adjustment section, this is independent of the utilization
rate of the dryer involved in the test.
An additional benefit derived from this task was a reduction in
operating costs resulting from a reduction in the natural gas consumption
of the boiler. By operating the boiler for desorption only at the end
of the day, as opposed to all day as designed, a reduction in gas con-
sumption of 47 percent was achieved.
An associated reduction in capital costs is also achieved by
operating the system in this manner. By desorbing only at the end of
the day, when the laundry's process steam requirements are down, it is
possible to desorb the beds with the existing plant steam system. This
would negate the need for the additional boiler. Additionally, at the
end of the day, the plant's cooling water system could be used to operate
the carbon system condensers which are needed only during desorption.
This, in conjunction with the air cooler reduction test to be described
in the Air Cooler Reduction section, could eliminate the need for the
auxiliary cooling tower presently installed with the system.
Carbon Bed Depth Adjustment—
This task involved two breakthrough tests during which the carbon
adsorption system was operated without desorption until complete satu-
ration of the carbon beds was obtained. In both tests, breakthrough
began to occur after 14 dryer cycles and saturation occurred during the
third day of consecutive adsorption. The beds were then steamed for 3 h
each and after each test, approximately 445 1 (118 gal) of solvent were
recovered. The two tests were conducted several weeks apart in order to
ensure that the beds had returned to equilibrium prior to the second
test.
26
-------
The,depth of the mass transfer zone (MTZ) of the carbon beds was
calculated by the following equation:^
MTZ = 0.8
where MTZ = Mass transfer zone depth (m)
Ss = quantity of solvent recovered at saturation (1)
SB = quantity of solvent recovered at breakthrough (1)
Q.8 = depth of carbon beds (m)
As previously mentioned, breakthrough began to occur with this
system after 14 dryer cycles. The value SR, therefore, was the average
quantity of solvent recovered after days using 14 dryer loads.
The results of the breakthrough test showed an MTZ of 0.8 m (30
in). With this information,'it was immediately obvious that no carbon
could be removed from the beds without seriously affecting the system
efficiency.
An additional result of the breakthrough tests was an analysis of
the capacity of a two-bed carbon adsorption system versus the operating
utilization of the Valley dry cleaning facility. Present operations
average 14 dryer loads per day at 113 kg (250 Ib) per load. This yields
a total cleaning rate of 1582 kg (3420 Ib) per day with 227 kg (500 Ib)
of solvent transferred from the dryer to the adsorber. Based on a dryer
capacity of 181 kg (400 Ib) per load and an operating maximum of 17
loads per an 8-h day, full utilization of the Valley dryer would process
approximately 3077 kg (6770 Ib) of clothes with 445 kg (980 Ib) of
solvent entering the adsorber. The dryer is, therefore, being operated
at approximately 51 percent utilization. From the breakthrough analysis,
it is estimated that approximately 480 kg (1060 Ib) of solvent can be
adsorbed before the emission reduction efficiency (Method 1) drops below
the 90 percent level (see Figure 5-1). This is equal to 0.132 kg
solvent per kg of carbon. On the basis of this information, it can be
concluded that the existing two-bed system is of sufficient size to
handle the emissions from the Valley dryer when 100 percent utilized.
Figure 5-2 depicts the relationship between the dryer utilization and
the emission reduction efficiency. Included in this figure is a repre-
sentation of the estimated adsorber efficiency if 15 cm (6 in) of
carbon were added to the beds. It is estimated that this addition, which
could easily be accomplished with the existing carbon tanks, would add
approximately 68 kg (150 Ib) of adsorptive capacity to the beds. This
would allow more dryer cycles to be adsorbed; however, the estimated
impact upon the emission reduction efficiency would be negligible.
Desorption Alteration--
Steam rates were varied in order to obtain the optimum desorption
parameters. The first step involved increasing the steam gauge pressure
from 10.3 x 10 to 13.8 x 10 pascals (15 - 20 psig) in order to obtain
27
-------
400
no
CO
100
200
300
400 500 600 700 800
Cumulative Solvent into Adsorber - kg
900
1000
Figure 5-1. Breakthrough test: Cumulative inlet and outlet measurements.
-------
100
99
98
97
96
95
94
93
92
25 50
75
TOO
Dryer Utilization (percent)
Figure 5-2. Emission reduction efficiency versus dryer utilization.
-------
a higher temperature steam. No change in efficiency was noted and the
increased steam temperature was considered to be potentially detrimental
to the carbon.
The next step involved a reduction in the length of the steam cycle
from the design length of 60 min. Desorption was conducted at 590 kg/h of
steam (1300 Ib/h) for 45 min. with the result being a noticeable reduction
in the adsorber efficiency. The length of the steam cycle was then
increased to 50 min. A reduction in efficiency was still noted. The
optimum desorption parameters were, therefore, determined to be as
follows:
Steam gauge pressure - 10.3 x 10 pascals (15 psig).
Steam flow rate - 590 kg/h (1300 Ib/h).
Length of cycle per bed - 60 min.
Air Cooler Reduction--
Water flow through the dryer exhaust air cooler was reduced in
three steps until it was completely eliminated. The inlet air stream to
the adsorbers and the carbon bed temperatures were monitored closely
throughout the test. At no time did either temperature exceed the
recommended maximum of 57°C (135°F).2 The air cooler could, therefore,
be eliminated, thus reducing the capital requirements of the total
system. Additionally, as discussed in the Adsorption/Desorption Cycle
Alteration section, this modification, in conjunction with the reduction
in cooling water throughput to the condensers, eliminated the need for
the additional cooling tower. Capital requirements are, therefore,
further reduced.
Limiting Conditions
The extent to which modifications could be made was limited by
several conditions. For the change of filter system, an excessive flow
restriction would limit the extent to which the filter could be modified.
Nylon bags were tested; however, they provided a flow restriction to the
extent that a maximum of three dryer cycles could be completed before
the bag had to be changed. When replaced with cotton bags, the problem
was eliminated and one bag could be operated for an entire day.
The only possible limiting condition for the blower cycle altera-
tion would be an increase in electricity consumption due to the start-
up surge. This was not witnessed; therefore, the condition does not
affect this system.
The limiting condition for the adsorption/desorption cycle altera-
tion, carbon bed depth adjustment, and desorption alteration was a
reduction in system efficiency. As previously delineated, no signifi-
cant reduction was noted when the system was switched to the continuous
operation of two beds. For the carbon bed depth adjustment, this limit
was passed during the desorption alteration and a reduction in efficiency
30
-------
was noted. The alterations were, therefore, reversed and the efficiencies
returned to normal.
EVALUATION OF TECHNICAL EFFICIENCY
Techniques
This section describes the techniques which are used to evaluate
the technical efficiency of the demonstration carbon adsorption system.
Three analysis criteria are used:
1. Emission reduction efficiency (Method 1).
2. Solvent recovery efficiency (Method 2).
3. Quality of recovered solvent.
Desired Technical Efficiency--
The minimum emission reduction efficiency deemed acceptable for
this system is 90 percent on a daily average basis. No minimum effi-
ciency was established for solvent recovery; however, it is directly
related to Method 1 and should, therefore, be comparable. The only
requirement for the quality of the recovered solvent is that it must be
acceptable for reuse in the dry cleaning plant.
Emission Reduction Efficiency —
As described in Section 4 of this report, the reduction in effluent
mass flow rate was determined by measuring the amounts of solvent enter-
ing and exiting the carbon adsorption unit. The unit efficiency was
calculated by the following equation:
Sn
Si = 100 1- «2.
^i
where Sx = Method 1 efficiency %
S = Solvent air emissions exiting the adsorption unit (1)
S. = Solvent entering the adsorption unit (1)
As defined in Section 7 of this report, there are potential errors
involved in the measurement of the inlet and outlet solvent mass flow
rates which may have an impact on the calculated adsorber efficiencies.
Thus, in order to determine the statistical confidence of the calculated
adsorber solvent emission reduction efficiency, the following equations
are used:
Minimum adsorber solvent emission reduction efficiency
so
S =100 1 - max
min
31
-------
where Si = minimum emission reduction efficiency
min
S = maximum solvent air emissions from adsorber assuming mea-
max surement errors are all on the low side (1/yr)
S. = minimum solvent flow rate to adsorber assuming measurement
min errors are all on the high side (1/yr)
Maximum adsorber solvent emission reduction efficiency
/
Sl = 100 1 -
max '
*"•
where Si = maximum emission reduction efficiency
max
S = minimum solvent air emissions from adsorber assuming mea-
min surement errors are all on the high side (1/yr)
S. = maximum solvent flow rate to adsorber assuming measure-
max ment errors are all on the low side (1/yr)
Solvent Recovery Efficiency—
The amount of solvent that was recovered for reuse by Valley was
measured daily. The Method 2 or solvent recovery efficiency was calcu-
lated by the following equation:
where S2 = Method 2 efficiency (%)
SD = Solvent recovered for reuse (1)
K
S. = Solvent entering the adsorption unit (1)
Maximum and minimum solvent recovery efficiencies are calculated in
the same manner as the emission reduction efficiency.
Quality of Recovered Solvent--
Samples of recovered solvent were taken periodically during the
test program and subjected to a series of laboratory analyses. The
results from these analyses were compared with the expected values for
fresh solvent to determine the acceptability of the recovered solvent.
Laboratory tests included:
1) Distillation range.
2) Acidity.
3) Kauri-Butanol value.
4) Bromine number
5) Flash point.
6) Solvent composition (by gas chromatograph).
32
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Results: Pre-optimization
The carbon adsorption system was operated from July 24 through
November 30, 1978, in the manner which was specified by the manufac-
turer. This section summarizes the data collected during that period.
Emission Reduction Efficiency—
Throughout the test period prior to optimization, a total of 22,834 1
(6,032 gal) of solvent entered the adsorber and 193 1 (51 gal) of solvent
were emitted into the atmosphere from the adsorber outlet. This yielded
an efficiency of 99.2 percent. It must be noted that approximately 7
weeks of operation were required to fully develop a "solvent heel" in
the carbon beds. A solvent heel is a quantity of solvent which is
adsorbed by the carbon but is never desorbed during normal steaming. It
is, therefore, constantly retained in the beds. After this heel was
formed, the emissions increased slightly. After this point, a total of
15,077 1 (3,983 gal) of solvent entered the adsorber and 174 1 (46 gal)
of solvent were emitted to the atmosphere, yielding an efficiency of
98.8 percent. This latter figure is more representative of the long-
term operations of this system since the heel remains constant and has
no further effect on the unit operation.
To calculate S , S , S. , and S. , the maximum expected
min max min max
error for each of the respective process operating parameters, as calculated
in Section 7, is used in conjunction with the measured solvent flow
rates into and out of the carbon adsorption unit.
Using the above equations, the following values can be calculated
for the demonstration program before optimization:
Minimum Maximum
S. - 1 (gal) 18,267 (4,826) 28,085 (7,419)
SQ - 1 (gal) 41 (11) 243 (64)
S1 Efficiency 98.7% 99.9%
For the period of operation after attainment of the heel, the
minimum and maximum values for solvent flow rate into the adsorber,
solvent air emissions from the adsorber, and emission reduction
efficiencies are:
Minimum Maximum
S. - 1 (gal) 12,062 (3,186) 18,545 (4,899)
$1 - 1 (gal) 134 (35) 228 (60)
Sufficiency 98.1% 99.3%
33
-------
Even under the assumption of worst possible measurement errors, the
emission reduction efficiency of the adsorption unit far exceeds the
minimum requirement of 90 percent.
Solvent Recovery Efficiency--
Throughout the entire demonstration program, a total of 16,202 1
(4,280 gal) of solvent was recovered. When compared to the solvent
inlet of 22,834 1 (6,032 gal), this yields a Method 2 efficiency of 71.0
percent. After attainment of the heel in the beds, 11,424 1 (3,018 gal)
of solvent were recovered, while 15,077 1 (3,983 gal) entered the system
from the dryer exhaust. The solvent recovery efficiency during this
period increased to 75.8 percent.
As with the emission reduction efficiency calculations, potential
errors exist in the measurement of recovered solvent. The minimum and
maximum solvent recovery efficiency, based on the errors associated with
measurement of the recovered solvent during the demonstration period,
are presented below: ,
Minimum Maximum
S. - 1 (gal) 18,267 (4,826) 28,085 (7,419)
SR - 1 (gal) 13,771 (3,638) 18,632 (4,922)
S2 Efficiency 49% 102%
The following data are for the adsorption unit after formation of
the heel, but before optimization:
Minimum Maximum
S. - 1 (gal) 12,061 (3,186) 18,545 (4,899)
SR - 1 (gal) 9,711 (2,565) 13,138 (3,471)
S2 Efficiency 52% 109%
Comparison of Methods—
The reported Method 1 and Method 2 efficiencies for the demonstration
program of 99.2 percent and 71 percent, respectively, leave 28.2 percent
unaccounted for in the carbon adsorption system. However, within the
confines of the measurement errors imposed on the system, this difference
is considered insignificant as shown by the maximum Method 2 efficiencies
both for the full demonstration period and after attainment of the heel
being greater than 100 percent (i.e., the maximum quantity of solvent
recovered is greater than the minimum quantity of solvent entering the
carbon adsorption system).
Quality of Recovered Sol vent--
In order for the recovered solvent to have any economic value, it
must not undergo any physical or chemical changes during the adsorption
and desorption stages. Analyses of the unused and recovered solvents
34
-------
were conducted weekly during the demonstration program. Invariably,
there was no difference detected between the two solvent samples. In
addition, no reduction in cleaning quality was reported by Valley. Some
of the solvent which was tested had been through the cycle several times
and still showed no signs of degradation. The obvious conclusion of
these tests is that carbon adsorption and subsequent desorption did not
adversely affect the quality of the Stoddard solvent in any way. The
results of the laboratory analyses are presented in Section 6 of this
report.
Results: Optimized System
The optimization of the carbon adsorption system removed the need
for the auxiliary boiler, cooling tower, air stream cooler, and one of
the three carbon beds. The optimized system utilized parallel adsorp-
tion with two carbon beds for the entire operating day. Desorption
occurred at the end of the day thus making it possible to use the
existing plant steam and cooling water systems if desired. The specific
desorption parameters are presented in the Optimization Studies section.
Emission Reduction Efficiency—
The emission reduction efficiency (Method 1) was calculated for the
optimized system configuration. During the time when the system was
operated at the optimum conditions, a total of 7,336 1 (1,938 gal) of
solvent entered the adsorber and 379 1 (100 gal) of solvent were emitted
to the atmosphere. This yielded an efficiency of 94.8 percent. Taking
into account the maximum possible inlet and outlet measurement errors,
the following ranges of figures were calculated for the optimized system:
Minimum Maximum
Si - 1 (gal) 5,871 (1,551) 9,023 (2,384)
SQ - 1 (gal) 291 (77) 496 (131)
Sl Efficiency 91.6% 96.8%
As with the data from the demonstration program, the system effi-
ciency exceeded the minimum requirement of 90 percent for a daily average,
even under the assumption of worst possible measurement errors.
Solvent Recovery Efficiency—
The solvent recovery efficiency (Method 2) for the optimized system
was determined as follows. During the time when the system was operated
at the optimum conditions, a total of 6,462 1 (1,707 gal) of solvent was
recovered. When compared with the inlet of 7,336 1 (1,938 gal), an
efficiency of 88.1 percent was calculated. The effect of maximum
possible errors on these figures is:
35
-------
si-
SR-
S0 El
1
1
Ff
(gal)
(gal)
iciency
Minimum
5,871 (1,551)
6,397 (1,690)
71%
Maximum
9,023 (2,384)
6,526 (1,724)
111%
Comparison of Methods—
Again, within the confines of measurement error, it was shown that
the difference in the quantity of solvent introduced into the carbon
adsorption system and the quantity of recovered solvent was insignificant
(as shown by the maximum Method 2 efficiency being greater than 100%).
COST ANALYSIS
Cost Analysis for Non-Optimized System
Capital cost data for the carbon adsorption system as originally
installed at the Valley site are presented in Table 5-1. These costs
include all necessary expenditures, including equipment costs, instal-
lation labor charges, contractor and subcontractor fees, engineering
service charges resulting from the design and installation of the carbon
adsorption system, and other related charges.
The costs included in this analysis are for the carbon adsorber;
carbon; all ancillary equipment; shipping costs for the carbon adsorber
from Minneapolis, Minnesota, to Anaheim, California; and the carbon
shipping charges from West Virginia. Included in the cost of the boiler
and cooling tower are charges for water softening and water treatment
chemicals. Engineering labor charges under the heading "Procurement,
Design, and Installation Supervision Costs" include those costs necessary
to develop the design parameters for the original carbon adsorption
system; to provide engineering supervision during the installation and
start-up of the system; and technical labor charges for assistance in
the installation and start-up period. Also included in the engineering
labor charges are those costs associated with project management.
It should be noted that some of the costs comprising the total
capital cost of the carbon adsorption system are site-specific and would
not necessarily be required if such a system were installed at some
other dry cleaning facility. The following items are considered site-
specific for the Anaheim site:
1. Bridge.
2. Boiler - steam supply is inadequate for both plant needs
and requirements of carbon adsorption system.
3. Air compressor - compressed air supply is inadequate for
both plant needs and requirements of carbon adsorption system.
36
-------
TABLE 5-1. CAPITAL COSTS FOR THE NON-OPTIMIZED CARBON ADSORPTION SYSTEM
(All costs are in mid-1978 dollars)
EQUIPMENT COSTS:
Equipment ' Cost
Carbon adsorber (less carbon)+ $59,000.*
Carbon (5500 Kilograms) (1200 Ib) 18,100.*
Boiler (0.5MW) (50hp) 12,100.
Cooling tower 4,400.
Bridge 2,200.
Pump (cooling tower) 700.
Air compressor 800.
SUBTOTAL EQUIPMENT COSTS. $ 97,300.
SITE PREPARATION AN© INSTALLATION COSTS:
Equipment or Service Provided
Field-construction services, necessary
installation equipment, foundation, duct-
work, piping, electrical work, and other
necessary ancillary equipment $44,200.
SUBTOTAL SITE PREPARATION COSTS $ 44,200.
PROCUREMENT, DESIGN, AND INSTALLATION SUPERVISION COSTS:
Service Provided
Engineering labor $18,000.
Travel 5,000.
Procurement expenses 5,000.
Miscellaneous 1»000-
SUBTOTAL PROCUREMENT, DESIGN, AND
INSTALLATION SUPERVISION COSTS $ 29,000.
TOTAL CAPITAL COSTS $170,500
*Includes shipping charges.
+Carbon adsorber sized for flow rate of 220 Nm /min.
37
-------
4. Cooling tower - cooling water needs for both the plant and
the carbon adsorption unit exceed the existing capacity.
In addition, since many variables enter into the required engineering
labor hours, depending on plant location, these costs could vary either
up or down for individual plant sites.
From the above costs, annualized operating costs for the non-
optimized adsorption system can be estimated using the following inputs:
1. Capital recovery factor calculated using 10 percent annual
interest rate, 15 yr equipment life, plus 4 percent of
installed capital cost for property taxes, insurance, and
administration.
2. Operating labor cost computed at $8.00/h plus an
additional 60 percent for overhead.
3. Natural gas cost of $0.0763/m3 ($0.0022/ft3).
4. Electricity cost of $0.0528/kWh.
5. Process water cost of $0.108/1000 1 ($0.410/1000 gal).
Operating labor hours were those hours attributed to proper opera-
tion and maintenance of the carbon adsorption system and are identified
in Section 6 of this report.
For the 18 week Demonstration Test, before optimization, the
annualized operating costs are given in Table 5-2. From operating data
obtained during this period, it was determined that 3.2 h of operating
and maintenance labor were required each day to properly operate and
maintain the carbon adsorption system. For purposes of computing
annualized operating labor charges, it was assumed the plant operated 5
days per week, 52 weeks per year. Utilities costs were derived from
actual rates charged to the dry cleaning plant during the Demonstration
Test. Since a full year's d^ta were not available to determine the
actual maintenance materials expenditures, an estimate was made based on
the Demonstration Test period and manufacturer's recommendations. Due
to the extremely limited data available on the life of carbon used in a
petroleum dry cleaning carbon adsorption system, it was assumed no
change of carbon was needed during the expected life of the system (15
yr). This assumption is based on manufacturer's estimates. The annualized
cost for the land on which the carbon adsorption system is located was
computed using a discount rate of 10 percent per year and a land appre-
ciation rate of 5 percent per year. The land charge was based on a 15
yr operating period.
Taking into account solvent recovery credits (using a solvent
recovery value of $0.16/1 ($0.61/gal), the annualized operating cost of
the non-optimized carbon adsorption system as originally installed was
estimated to be $42,500.
38
-------
TABLE 5-2. ANNUALIZED OPERATING COSTS OF NON-OPTIMIZED
CARBON ADSORPTION SYSTEM
(All costs are in mid-1978 dollars)
DIRECT COSTS:
Utilities
Natural gas
Process water
Electricity
Operating Labor
Direct labor
Supervision
Maintenance
Annual
Quantity
45,600m3,
(1,612,000ft-3)
1,338,400 1
(353,600 gal)
70,900kWh
Unit Cost
$0.0763/m3,
($0.0022/fr)
$0.108/1000 1
($0.410/1000 gal)
$0.0528/kWh
310 man-hours $12.60/man-hour
15% of Direct labor
Labor
Material
Recovered Solvent (credit)
470 man-hours $12.60/man-hour
54,800 1
(14,500 gal)
$0.16 1
($0.61/gal)
Total
Annual Cost
$3,500
100
3,700
3,900
600
5,900
< 200
(8,800)
SUBTOTAL DIRECT COSTS $9,100
INDIRECT COSTS:
Capital Charge at 13.15% of Total Capital
Costs Plus 4.0% of Equipment Costs
Overhead
Plant (50% of operating labor and maintenance)
Payroll (20% of operating labor)
Land Charge
SUBTOTAL INDIRECT COSTS.
TOTAL ANNUAL OPERATING COSTS.
$26,300
5,300
900
900
.|33j400
.$42,500
39
-------
Cost Analysis for Optimized System
Cost data for the optimized carbon adsorption system are the same
as for the non-optimized system except as follows:
1. No boiler or cooling tower is required, since the existing
plant equipment can be,utilized.
2. Only two of the three carbon adsorption system canisters are
needed to operate the optimized system (with a resultant
reduction in carbon requirements).
3. No cooling tower pump is required, since the cooling tower is
not needed.
4. No air compressor is required, since the plant air supply
system can be used for the after-hours desorption.
5. Field-construction services, necessary equipment, foundation
work, electrical work, and the like are reduced, though not
linearly.
6. No change is experienced in procurement, design, and instal-
lation supervision costs.
•'.
7. No air cooler is needed, since the temperature of the gas
stream entering the carbon adsorption system never exceeded
the recommended maximum of 57°C (135°F).
8. The land requirements of the optimized carbon adsorption
system are reduced by approximately 40 percent, since equipment
requirements have been reduced.
Using the above assumptions, the capital costs for the optimized
system are given in Table 5-3.
It was felt that no decrease in procurement, design, and instal-
lation supervision costs would be experienced. Additionally, it was
assumed that the site preparation and installation costs for the
optimized adsorption system would be 90 percent of the comparable costs
for the originally designed system, since foundation work, piping needs,
ducting requirements, and electrical installation work (which make up
the majority of site preparation and installation costs) are basically
the same for the originally-designed system and the optimized system.
Using the same costing data (capital recovery factor, operating
labor, and the like) as the original carbon adsorption configuration,
with the additional cost of $0.0763/kg ($0.0346/1b) of low-pressure
steam, annualized costs for the optimized system are estimated (Table 5-4)
40
-------
TABLE 5-3. CAPITAL COSTS FOR THE OPTIMIZED CARBON ADSORPTION SYSTEM
(All costs are in mid-1978 dollars)
EQUIPMENT COSTS:
Equipment
Carbon adsorber (less carbon)
Carbon (3,600 kilograms) (7,900 Ib)
Bridge
Capital Cost
$45,200.*
12,100.*
2,200.
SUBTOTAL EQUIPMENT COSTS.
SITE PREPARATION AND INSTALLATION CHARGES:
Equipment or Service Provided
Field-construction services, necessary
installation equipment, foundation, duct-
work, piping, electrical work, and other
necessary ancillary equipment
* • *
$39,800.
SUBTOTAL SITE PREPARATION COSTS.
PROCUREMENT, DESIGN, AND INSTALLATION SUPERVISION COSTS:
Service Provided
Engineering labor
Travel
Procurement expenses
Miscellaneous
$18,000.
5,000.
5,000.
1,000.
SUBTOTAL PROCUREMENT, DESIGN AND
INSTALLATION SUPERVISION COSTS. .
TOTAL CAPITAL COSTS. .
$ 59,500.
$ 39,800.
$ 29,000.
$128.300.
*Includes shipping charges.
41
-------
TABLE 5-4. ANNUALIZED OPERATING COSTS OF OPTIMIZED
CARBON ADSORPTION SYSTEM
(51% Utilization)
DIRECT COSTS:
Annual Total
Utilities Quantity Unit Cost Annual Cost
Steam 322,600 kg $0.0073/kg $ 2,400
(709,700 Ib) ($0.0033/lb)
Process water 767,600 1 $0.108/1000 1 <100
(202,800 gal) ($0.410/1000 gal)
Electricity 61,200 kWh $0.0538/kWh 3,200
Operating Labor
Direct labor 200 man-hours $12.60/man-hour 2,500
Supervision 15% of Direct labor 400
Maintenance
Labor 320 man-hours $12.60/man-hour 4,000
Materials <200
Recovered Solvent (credit)
61,500 1 $0.16/1 (9,800)
(16,200 gal) ($0.61/gal)
SUBTOTAL DIRECT COSTS. ... $ 3,000
INDIRECT COSTS:
Capital Charge at 13.15% of Total
Capital Costs Plus 4-0% of Equipment Costs $19,300
Overhead
Plant (50% of operating labor and maintenance) 3,600
Payroll (20% of operating labor) 600
Land Charge 500
SUBTOTAL INDIRECT COSTS. . . $24,000
TOTAL ANNUAL OPERATING COSTS. . . $27,000
42
-------
These costs are based on the following inputs:
1. 2.1 hours of operating and maintenance labor per day are required
to ensure satisfactory performance.
2. Plant operation is 8 hours per day, 5 days per week, 52 weeks per year.
3. No carbon change is necessary during the useful life of the
adsorption system (based on manufacturer's estimates).
Computation of the annualized operating costs for the optimized
carbon adsorption system gives a result of $27,000. This result, coupled
with the estimated annual solvent emissions reduction of 48 Mg (53 tons)
per year, gives a cost effectiveness of $560/Mg ($510/ton) of solvent
emissions reduction. Cost effectiveness, as computed on a cost per unit
of emissions reduction, is used by both EPA and industry as a means of
evaluating various pollution control technologies on a common basis.
Effect of Dryer Utilization--
A sensitivity analysis was performed to determine the effect of
dryer utilization on both the annualized operating costs and cost-
effectiveness (Figures 5-3 and 5-4, respectively). This analysis is
based on the following assumptions:
1. Steam and process water requirements at 100 percent dryer
utilization are unchanged from the 51 percent utilization
case. Steam and process water requirements at 25 percent
dryer utilization are halved from the 51 percent utilization
case because desorption is required only every other day.
2. Electricity costs are directly proportional to dryer utiliza-
tion.
3. Operating labor and materials do not vary for the 100 percent
dryer utilization case, but are reduced by one-third for the
25 percent dryer utilization case.
4. Solvent recovery credits are linearly proportional to dryer
utilization (since the change in the time-weighted solvent
emissions reduction is not significant).
Annualized operating costs for a 25 percent dryer utilization rate
and a 100 percent dryer utilization rate are given in Tables 5-5 and
5-6, respectively.
43
-------
30
- 25
20
en
c
15
10
10 20 30 40 50 60
Dryer Utilization - percent
70
90
TOO
Figure 5-3. Effect of dryer utilization on annualized operating costs.
-------
1200
1000 •
800
600
en
cu
c
0)
400
200
10 20 30 40 50 60
Dryer Utilization - percent
70
80
90
100
Figure 5-4. Effect of dryer utilization on cost effectiveness.
-------
TABLE 5-5. ANNUALIZED OPERATING COSTS OF OPTIMIZED
CARBON ADSORPTION SYSTEM
(25% Utilization)
DIRECT COSTS:
Utilities
Steam
Process water
Electricity
Operating Labor
Direct labor
Supervision
Maintenance
Labor
Materials
Recovered Solvent (credit)
Annual
Quantity
161,300 kg
(354,900 Ib)
471,300 1
(110,200 gal)
30,000 kWh
140 man-hours
15% of Direct
210 man-hours
Unit Cost
$0.0073/kg
($0.0033/lb)
$0.108/1000 1
($0.410/1000 gal)
$0.0528/kWh
$12.60/man-hour
labor
$12.60/man-hour
Total
Annual Cost
$ 1,200
<100
1,600
1,800
300
2,600
<200
30,200 1 $0.16/1 (4,800)
(8,000 gal) ($0.61/gal)
SUBTOTAL DIRECT COSTS. ... $ 3,000
INDIRECT COSTS:
Capital Charge at 13.15% of Total
Capital Costs Plus 4.0% of Equipment Costs $19,300
Overhead
Plant (50% of operating labor and maintenance) 2,400
Payroll (20% of operating labor) 400
Land Charge 500
SUBTOTAL INDIRECT COSTS. . . $22,600
TOTAL ANNUAL OPERATING COSTS. . . $25,600
46
-------
TABLE 5-6. ANNUALIZED OPERATING COSTS OF OPTIMIZED
CARBON ADSORPTION SYSTEM
(100% Utilization)
DIRECT COSTS:
Annual Total
Utilities Quantity Unit Cost Annual Cost
Steam 322,600 kg $0.0073/kg $ 2,400
(709,700 Ib) ($0.0033/lb)
Process water 767,600 1 $0.108/1000 1
-------
SECTION 6
TEST DATA
This section contains a summary of all data collected during the
demonstration and optimization studies. A detailed analysis of these
data was presented in Section 5 of this report.
OPERATION AS DESIGNED
Data was collected during the pre-optimization program which ran
from July 24, 1978, to November 30, 1978. The information collected
during that period is presented and summarized in this section.
Continuous Data
A listing of all daily operation data is presented in Tables 6-1
and 6-2. The methods by which these data were obtained are explained in
Section 4 of this report. A summary of the data for the entire demon-
stration program and of data collected after the attainment of the
solvent heel in the carbon beds is presented in Table 6-3.
Utility Consumption
As explained in Section 4, daily measurements were recorded of all
utility consumption rates during the demonstration program. Weekly con-
sumption rates were then tabulated and averages calculated. This
information is presented in Table 6-4.
Laboratory Test Data
As mentioned in Sections 4 and 5, weekly laboratory analyses of
neat and recovered solvent samples were performed during the demon-
stration program. The object of these analyses was to determine if any
solvent degradation occurred after the adsorption and desorption pro-
cess. The results of these tests are presented in Table 6-5. Shown
in Table 6-6 for comparison with Table 6-5, is a sample of typical
laboratory analysis results.
48
-------
TABLE 6-1. SUMMARY OF DRY CLEANING CARBON ADSORPTION DEMONSTRATION PROGRAM
OPERATING DATA (METRIC UNITS)
Julian
date
(1978)
205
206
207
208
209
212
213
214
215
216
219
220
221
222
223
226
227
223
229
230
233
234
235
236
237
240
241
24T
243
244
248
249
250
251
254
255
256
257
258
262
263
264
265
268
269
270
271
272
Electrical
consumption
of system
kWh
215
743
215
223
311
223
MB
ND
263
304
311
225
ND
309
316
277
299
355
310
310
258
356
309
356
401
308
402
351
353
317
264
310
351
306
263
267
264
224
265
310
262
250
199
300
305
259
349
319
Natural gas
consumption
of boiler
ft3
261
377
377
292
303
145
31
173
215
167
221
119
204
230
162
167
207
221
215
213
105
221
184
181
232
181
190
230
184
179
179
179
184
181
177
125
128
122
179
190
136
142
128
300
139
159
258
145
Water
consumption
of boiler
(1)
3179
5526
4769
ND
3596
1779
492
2044
2650
1968
2763
1514
2347
2687
2006
1590
2385
2877
2612
2574
1401
2801
2006
2120
2801
2120
2120
2952
2006
2082
2309
2082
2271
2082
2158
1438
1665
1363
2120
2347
1741
1628
1552
3444
1476
1930
3028
1779
Decanted
water to
sewer
(1)
1287
4542
4164
3028
3407
ND
ND
1893
2271
1893
2650
1514
1893
2650
1514
1893
2271
2650
2271
2271
757
3407
1893
1893
4164
1893
1893
2271
1893
1893
1893
1136
2650
1893
1893
1136
1136
1136
1136
757:
379
ND
ND
ND
ND
NO
ND
ND
Water flow
to tower
cooler
(1)
2915
4164
4277
3482
2763
1476
1098
2347
2309
2612
2915
1817
2498
2612
1741
2195
2460
2990
2460
2687
1703
2952
2612
3028
3558
2915
2801
3255
2952
2574
2877
606
2763
2763
2725
1703
2006
1665
2347
3444
3066
3861
2839
5678
3785
3066
4429
2915
Water flow
to
condenser
(1)
1041
149129
144966
155185
168054
116200
4921
182316
185465
184330
188872
151022
171461
185844
146858
159727
165026
1 77895
116200
ND
ND
ND
HD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Solvent
introduced
adsorber
(1)
76
125
129
95
170
64
ND
159
151
193
167
129
140
125
102
133
133
382
242
333
363
382
257
413
382
314
789
401
379
288
288
454
269
329
318
284
326
273
329
284
288
299
276
292
254
265
284
231
Solvent
air emissions
from adsorber
(1)
1.1
1.9
0.4
0.8
2.3
0.4
ND
0.4
0.4
0.4
0,0
0.4
0.0
0.0
0.0
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.8
3.8
9.5
3.8
1.1
1.1
1.1
0.8
5.3
3.0
1.5
1.5
1.9
Recovered
solvent
(D
*ND
125
57
1)4
114
38
ND
102
76
NO
114
45
106
95
76
ND
102
95
189
208
95
246
170
.216
295
170
151
284
246
254
246
257
246
246
239
170
151
227
239
208
133
208
133
239
114
227
220
151
No. dry
cleaning
cycles
(per day)
4
6
ND
4
6
2
4
7
6
7
7
6
7
6
4
7
6
14
10
12
T2
12
10
16
10
12
9
18
17
15
13
15
13
15
14
13
16
12
15
13
14
15
12
14
8
10
11
14
% Emissions
Recovered reduction
(weekly) (weekly)
79 98.9
58 99. 7
66 99.9
61 99.8
57 99.8
70 99 . 9
74 99 . 9
67 98.8
59 99.6
(continued)
-------
TABLE 6-1. (continued)
en
o
Julian
date
11978)
275
276
277
279
232
283
284
285
286
289
290
291
292
293
296
297
298
299
300
303
304
305
306
307
310
311
312
313
314
317
318
319
320
321
324
325
326
331
332
333
334
Electrical
consumption
of system
kWh
270
260
81
308
312
358
219
260
218
222
263
262
218
215
85
216
263
168
263
219
216
308
265
225
262
170
305
168
267
176
219
216
215
170
350
220
220
264
173
355
423
Natural gas
consumption
of boiler
ft3
105
173
62
179
173
170
133
173
113
173
125
173
125
167
68
119
170
125
173
125
176
179
176
128
173
119
314
116
167
116
116
159
111
102
150
110
153
161
116
272
167
- Water
consumption
of boiler
(1)
908
1968
908
2120
2271
1930
1476
2082
1363
2233
1476
2271
1438
215g
871
1552
2044
1628
2082
1552
2422
2195
3369
1476
2082
1401
3974
2612
1930
1438
1363
1855
1249
1476
1779
1477
1855
2082
1703
3293
2157
Decanted
water to
sewer
(1)
ND
ND
ND
ND
ND
ND
ND
HO
1136
1514
1136
1514
1136
1514
379
1136
1514
1136
1514
1136
1514
1514
1514
1136
1514
1136
3028
1136
1136
3407
757
1136
757
757
1136
1136
1136
1136
1136
2650
1893
Water flow
to tower
cooler
(1)
1628
2498
984
2512
2574
3066
2574
3066
2120
2990
2309
2839
2422
2309
1817
2877
4201
3142
3747
3028
3520
4315
4164
3066
4239
2915
5488
2915
3293
2574
2952
4239
3255
2422
3596
2801
3104
4466
2877
6094
3596
Water flow
to
condenser
(1)
120363
ND
ND
ND
150643
143073
120742
128312
112036
150643
112793
135503
118849
129447
53747
99167
143830
112036
135503
110522
119606
151022
130204
109765
127555
90462
152914
104088
117335
88569
101060
123770
99546
85541
189630
104845
116960
1 31 340
86680
1 74870
105600
Solvent
Introduced
adsorber
(1)
288
193
288
216
250
284
265
265
242
299
125
299
326
322
76
280
344
239
295
231
288
382
292
326
367
254
227
337
344
239
299
299
284
295
284
337
242
204
269
276
220
Solvent
air emissions
from adsorber
(1)
1.5
1.1
1.1
1.1
3.0
1.9
1.9
1.9
1.1
1.5
0.4
1.1
1.9
2.3
1.9
1.9
2.3
1.5
2.3
2.7
3.0
3.4
2.7
3.4
1.9
1.9
2.3
1.5
1.9
3.4
4.5
3.4
3.4
9.1
7.2
3.4
10.2
2.3
11.0
22.0
3.8
Recovered
solvent
(1)
140
227
76
265
189
341
151
303
201
303
208
303
189
341
95
170
303
170
310
167
261
254
280
140
257
189
360
102
284
144
136
257
174
182
114
238
189
160
29S
£_ Jj
129
No. dry
cleaning
cycl es
(per day)
15
4
17
11
13
14
13
12
12
15
6
14
14
13
4
12
15
11
15
11
11
15
13
14
15
11
15
14
16
11
14
16
13
13
15
14
10
14
14
11
I Emissions
Recovered reduction
(veeLly) (weeUy)
81 99.4
91 99.2
98 99.5
85 99.2
73 99.0
78 99.4
63 98.3
61 97.6
RO 9S Q
Ov j J , j
-------
TABLE 6-2. SUMMARY OF DRY CLEANING CARBON ADSORPTION DEMONSTRATION PROGRAM
OPERATING DATA (ENGLISH UNITS)
Julian
date
(1978]
205
206
207
208
209
212
213
214
215
216
219
220
221
222
223
226
227
228
229
230
233
234
235
236
237
240
241
242
243
244
248
249
250
251
254
25S
256
257
258
262
263
264
265
Electrical
consumption
of system
kWh
215
743
215
223
311
223
ND
ND
263
304
311
225
ND
309
316
277
299
355
310
310
258
356
309
356
401
308
402
351
35:)
317
264
310
351
306
263
267
264
224
265
310
262
250
199
Natural gas
consumption
of boiler
ft3
9.200
13.300
13.300
10,300
10,700
5,100
1,100
6,100
7,600
5,900
7,800
4,200
7,200
8,100
5.700
5,900
7.300
7,800
7,600
7.500
3,700
7.800
6,500
6,400
8,200
6,400
6,700
8,100
6,500
6,300
6,300
6,300
6.500
6,400
6,200
4,400
4,500
4.300
6.300
6,700
4,800
5,000
4,500
Water
consumption
of .boiler
(gal)
840
1.460
1,260
ND
950
470
130
540
700
520
730
400
620
710
530
420
630
760
690
680
370
740
530
560
740
560
560
780
530
550
610
550
600
550
570
380
440
360
560
620
460
430
410
Decanted
water to
sewer
(gal)
340
1.200
1,100
800
900
ND
ND
500
600
500
700
400
500
700
400
500
600
700
600
600
200
900
500
500
1.100
500
500
600
500
500
500
300
700
500
500
300
300
300
300
200
100
ND
ND
Water flow
to tower
cooler
fgalj
770
1,100
1,130
920
730
390
290
620
610
690
770
480
660
690
460
580
650
790
650
710
450
780
690
800
940
770
740
860
780
680
760
160
730
730
720
450
530
440
620
910
810
1,020
750
Water flow
to
condenser
(Sal)
275
39,400
38,300
41 ,000
44,400
30.700
1.300
48,300
49,000
48,700
49.900
39,900
45,300
49,100
38,800
42,200
43,600
47,000
30,700
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Solvent
Introduced
adsorber
fs.a.1)
20
33
34
25
45
17
ND
42
40
51
44
34
37
33
27
35
35
101
64
88
96
101
68
109
101
83
50
106
100
76
76
120
71
87
84
75
86
72
87
75
76
79
73
Solvent No. dry
air emissions Recovered cleaning
from adsorber solvent cycles
(gal) (gal) (per day)
0.3
0.5
0.1
0.2
0.7
0.1
ND
0.1
0.1
0.1
0.0
0.1
0.0
0.0
0.0
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.2
1.0
2F
.5
1.0
0.3
0.3
0.3
0.2
ND
33
15
30
30
10
ND
27
20
ND
30
12
28
25
20
ND
27
25
50
55
25
65
45
57
78
45
40
75
65
67
65
68
65
65
63
45
40
60
63
55
35
55
35
4
6
ND
4
6
2
4
7
6
7
7
6
7
6
4
7
6
14
10
12
12
12
10
16
10
12
9
18
17
15
13
15
13
15
14
13
16
12
15
13
14
15
12
% Emissions
Recovered reduction
(weekly) (weekly)
79 98.9
58 99.7
66 99.9
61 99.8
57 99.8
70 99.9
74 99-9
67 98.8
59 99-6
(continued)
-------
. TABLE 6-2. (continued)
en
ro
— — _____ — __ _ —
Julian
date
(1378^
268
269
270
271
272
275
276
277
279
282
283
284
285
286
289
?QO
C jv
291
292
293
?Qfi
C.jv
7Q7
£ 7 /
298
9QQ
L. J J
300
303
304
w;
.JU*J
•>nfi
*JwU
307
no
J 1 U
311
11?
j 1 £
11 1
J i O
314
Tl I
O 1 /
1-1 ft
J P O
11Q
•v i 5
i?n
JtU
321
324
325
326
331
332
333
334
Electrical Natural gas
consumption consumption
of system of boiler
JcWh ft3
300
305
259
349
319
270
260
81
308
312
358
219
260
218
222
263
262
218
215
85
216
263
168
263
219
216
308
265
225
262
170
305
168
267
176
219
216
215
170
350
220
220
264
173
355
423
10,600
4,900
5,600
9,100
5,100
3,700
6,100
2,200
6,300
6,100
6,000
4,700
6,100
4,000
6,100
4,400
6,100
4,400
5,900
2,400
4,200
6,000
4,400
6,100
4,400
6,200
6,300
6,200
4,500
6,100
4,200
11,100
4,100
5,900
4,100
4,100
5,600
3,900
3,600
5,300
3,900
5,400
5,700
4,100
9,600
5,900
Water
consumption
of .boiler
(gal)
910
390
510
800
470
240
520
240
560
600
510
390
550
360
590
390
600
380
570
230
410
540
430
550
410
640
580
890
390
550
370
1,050
690
510
380
360
490
330
390
470
390
490
550
450
870
570
Decanted Water flow Water flow Solvent Solvent
water to to tower to Introduced «1r emissions
sewer cooler condenser adsorber from adsorber
(gal) (sal) (sal) (sal) (gal)
ND
ND
ND
ND
NH
ND
ND
ND
ND
ND
ND
ND
ND
300
400
300
400
300
400
100
300
400
300
400
300
400
400
400
300
400
300
800
300
300
900
200
300
200
200
300
300
300
300
300
700
500
1,500
1,000
810
1,170
770
430
660
260
690
680
810
680
810
560
790
610
750
640
610
480
760
1,110
830
990
800
930
1,140
1,100
810
1.120
770
1,450
770
870
680
780
1,120
860
640
950
740
820
1,180
760
1,610
950
ND
ND
ND
NO
ND
31 ,800
ND
ND
ND
39,800
37,800
31 ,900
33,900
29,600
39,800
29,800
35,800
31 ,400
34,200
14,200
26,200
38,000
29,600
35,800
29,200
31 ,600
39,900
34,400
29,000
33,700
23,900
40,400
27,500
31 ,000
23,400
26,700
32,700
26,300
22,600
50,100
27,700
30,900
34,700
22,900
46,200
27,900
77
67
70
75
61
76
21
76
57
66
75
70
70
64
79
33
79
86
85
20
74
91
63
78
61
76
101
77
86
97
67
60
89
91
63
79
79
75
78
75
89
64
54
71
73
58
1.4
0.8
0.4
0.4
0.5
0.4
0.3
0.3
0.3
0.8
0.5
0.5
0.5
0.3
0.4
0.1
0.3
0.5
0.6
0.5
0.5
0.6
0.4
0.6
0.7
0.8
0.9
0.7
0.9
0.5
0.5
0.6
0.4
0.5
0.9
1.2
O.a
0.9
2.4
1.9
0.9
7.7
0.6
2.9
5.9
1.0
Recovered
solvent
(aaD
63
30
60
58
40
37
60
20
70
50
90
40
80
53
80
55
30
50
90
25
45
80
45
82
44
69
67
74
37
68
50
95
27
75
38
36
63
46
48
45
30
53
50
42
78
34
No. dry
cleaning
cycl es
(per day)
14
8
10
11
14
15
4
17
11
13
14
13
12
12
15
6
14
14
13
4
12
15
11
15
11
11
15
13
14
15
11
15
14
16
11
14
16
13
13
13
15
14
10
14
14
11
I
I Emissions
Recovered reduction
(weekly) (weekly^
72 99.0
81 99.4
91 99.2
98 99 5
85 99.2
73 99.0
78 99.4
53 98.3
61 97.6
80 95.9
-------
TABLE 6-3. DEMONSTRATION PROGRAM
CONTINUOUS DATA SUMMARY
ENTIRE DEMONSTRATION PROGRAM
Solvent into adsorber - 1 (gal) 22,834 (6,032)
Solvent emissions from adsorber - 1 (gal) 193 (51)
Solvent recovered - 1 (gal)., - 16,202 (4,280)
Natural gas consumption - m (ft ) 14,561 (514,200)
Electricity consumption - kWh 23,654
Water consumption - 1 (gal) 185,712 (49,060)
Wastewater to sewer - 1 (gal) 156,338 (41,300)
Method 1 efficiency 99%
Method 2 efficiency , 71%
i
DEMONSTRATION PROGRAM AFTER HEEL ATTAINMENT
Solvent into adsorber - 1 (gal) 15,077 (3,983)
Solvent emissions from adsorber - 1 (gal) 174 (46)
Solvent recovered - 1 (gal)~ , 11,424 (3,018)
Natural gas consumption - mj (ft0) 7,660 (270,400)
Electricity consumption - kWh 13,803
Water consumption - 1 (gal) 105,197 (27,790)
Wastewater to sewer - 1 (gal) ,' 82,901 (21,900)
Method 1 efficiency 99%
Method 2 efficiency 76*
53
-------
TABLE 6-4. DEMONSTRATION PROGRAM
WEEKLY UTILITIES CONSUMPTION OF THE CARBON ADSORPTION UNIT
Week of
(1978) ,
July 24
July 31
August 7
August 14
August 21
August 28
September 4
September 11
September 18
September 25
October 2
October 9
October 16
October 23
October 30
November 6
November 13
November 20
November 27
Average
Natural gas
consumption
9 6
61.9
28.1
35.9
39.3
35.5
37.1
27.8
28.0
22.9
43.3
20.0
29.2
29.2
25.1
30.1
34.2
23.2
10.6
27.6
31.3
(58.6)
(26.6)
(34.0)
(37.2)
(33.6)
(35.1)
(26.3)
(26.5)
(21.7)
(41.0)
(18.9)
(27.7)
(27.7)
(23.8)
(28.5)
(32.4)
(22.0)
(15.1)
(26.1)
(29.6)
Electricity
consumption
109 J/Wk (106 Btu/wk)
6.1
ND
ND
5.6
6.0
6.2
4.4
4.6
3.7
5.5
3.3
5.0
4.2
3.6
4.4
4.2
3.6
2.9
2.9
4.4
(5.8)
(ND)
(ND)
(5.3)
(5.7)
(5.9)
(4.2)
(4.4)
(3.5)
(5.2)
(3.1)
(4.7)
(4.0)
(3.4)
(4.2)
(4.0)
(3.4)
(2.7)
(2.7)
(4.2)
Water
consumption
103 1/wk (103 gal/wk.)
ND
9.1
11.4
12.1
11.0
11.4
8.7
8.7
7.2
11.7
6.1
9.1
9.5
8.3
11.0
12.1
7.6
5.3
9.1
9.5
(ND)
(2.4)
(3.0)
(3.2)
(2.9)
(3.0)
(2.3)
(2.3)
(1.9)
(3.1)
(1.6)
(2.4)
(2.5)
(2.2)
(2.9)
(3.2)
(2.0)
(1.4)
(2.4)
(2.5)
Wastewater
to sewer
ID3 1/wk (103 qal/wk)
16.3
ND
10.2
11.4
12.1
9.8
7.6
6.4
ND
ND
ND
ND
6.8
5.7
6.8
7.9
6.8
3.4
6.8
8.3
(4.3)
(ND)
(2.7)
(3.0)
(3.2)
(2.6)
(2.0)
(1.7)
(ND)
(ND)
(ND)
(ND)
(1.8)
(1.5)
(1.8)
(2.1)
(1.8)
(0.9)
(1.8)
(2.2)
Conversion: 1031 Btu/ft natural gas.
bConversion: 3414 Btu/kWh.
CND - No data.
54
-------
TABLE 6-5. COMPARISON OF PROCESS SOLVENT AND RECOVERED SOLVENT PROPERTIES
Week of July July Aug Aug Aug Aug Sept Sept Sept Sept Oct Oct Oct Oct Oct Nov Nov
(1978) 24 31 7 14 21 28 4 11 18 25 2 9 16 23 30 6 13
I. Distillation range difference between
process solvent and recovered solvent
(in °C)
(% solvent evaporated)
0
2
5
10
20
30
40
50
60
70
75
80
90
95
end point
II. Acidity difference between process
solvent and recovered solvent
(mg eq KOH/100 ml)
III. Kauri-Butanol Value difference between
process solvent and recovered solvent
IV. Bromine number difference between process
solvent and recovered solvent
V. Flash point difference between process 3 1 1 NO ND NO
solvent and recovered solvent
(°C)
VI. Solvent composition difference as
determined by gas chromatograph
(volume % by carbon fraction)
C12
C13
C14+C15
C16
cm
VII. Solvent content of wastewater (ppm) 0.25 0.25 0.08 0.16 0.11 0.12 0.12 0.01 0.01 0.02 0.01 0.01 0.01 0.03 0.05 0.02 0.12
0.0
2.0
0.0
0.5
1.5
1.0
1.5
2.0
2.0
2.0
2.3
2.0
4.0
5.0
6.0
5.1
1.0
kNO
0.0
0.0
0.5
1.0
0.0
0.0
1.0
1.0
0.5
0.0
1.0
1.0
0.0
2.5
4.0
5.1
1.0
NO
0.0
1.0
1.0
1.0
0.5
1.0
0.5
1.0
1.0
0.5
0.5
0.5
1.0
1.5
5.0
0.0
0.5
ND
1.0
0.0
0.5
0.5
1.0
1.0
1.0
0.5
1.0
1.5
1.5
2.0
2.0
0.5
3.0
0.0
0.5
ND
1.0
1.0
0.5
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
0.5
1.0
0.0
0.0
0.0
0.5
ND
1.0
0.0
0.0
0.0
0.5
0.5
0.0
0.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
0.0
0.5
ND
Q.O
0.0
1.0
1.0
0.0
0.0
1.0
1.0
0.5
1.0
1.0
0.5
0.0
1.5
0.5
0.0
0.2
ND
1.0
1.0
1.0
0.0
1.0
1.0
0.0
1.0
0.5
0.5
0.5
0.5
0.0
3.0
4.0
8.2
0.0
ND
1.5
1.0
2.0
1.5
1.5
1.5
1.5
1.0
1.0
0.5
0.0
0.0
0.5
1.0
0.5
5.1
0.0
ND
1.0
2.0
0.5
1.0
1.0
0.5
0.0
0.5
1.0
1.0
0.5
1.0
2.0
1.0
1.0
5.1
0.5
ND
1.0
1.0
1.0
1.0
1.5
1.0
1.5
2.0
1.0
1.0
0.5
1.0
1.0
1.5
0.5
0.0
0.2
0.2
1.0
1.0
0.5
0.5
1.0
1.0
1.5
1.0
0.5
1.0
1.0
1.0
2.0
2.5
3.0
5.9
0.0
0.4
1.0
1.0
1.0
2.0
2.0
0.5
1.0
3.0
1.0
1.0
1.0
1.0
1.5
1.5
3.0
0.0
0.0
0.7
0.0
0.5
0.5
0.5
0.0
0.5
0.5
0.0
0.5
0.5
0.0
0.0
3.0
4.0
3.0
0.0
0.0
0.8
1.0
1.0
2.0
1.0
0.5
0.0
0.5
1.0
1.0
1.0
1.0
1.0
1.0
0.0
1.0
0.0
0.4
0.0
0.0
2.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
0.0
0.5
0.5
1.0
0.5
0.0
5.1
0.0
0.2
1.0
1.0
1.0
1.0
0.5
1.0
1,5
1.5
2.0
2.0
1.0
1.0
4.0
2.0
3.0
0.0
0.5
0.0
1.0
2.0
1.3
1.2
1.4
0.1
0.2
2.0
0.1
2.4
0.8
0.8
2.1
3.9
2.4
0.4
6.6
1.7
1.3
0.6
0.9
1.7
0.2
1.5
1.3
0.2
1.9
0.1
1.0
3.0
2.5
1.3
1.8
0.4
0.2
0.7
0.2
1.6
2.1
0.4
0.9
0.8
0.1
1.8
0.1
1.9 1.1 0.4 3.0 1.4 0.6
1.5 4.4 0.9 0.7 0.9 5.2
1.1 2.7 0.1 0.3 1.8 0.8
0.7 1.8 0.1 0.8 0.4 1.5
0.8 5.2 0.5 2.6 4.6 2.3
1.6
1.9
1.5
0.6
1.8
2.8
1.7
2.2
0.5
2.0
-------
TABLE 6-6. TYPICAL ANALYSIS OF STODDARD SOLVENT
Distillation
Range-percent
IBP
2
5
10
20
30
40
50
60
70
75
80
90
95
EP
Acid # (mg KOH/ml )
KB Value
Br # (mg Br/ml )
Flash Point OG
Gas Chromatography
C12
C13
C14-15
C16
cm
Wastewater - Solvent
Neat Solvent
°C
155
157
1 58
160
162
164
.165.5
167
169
172
173
175
179
182
183
15.3
30.1
0.3
34.4
13.7%
23.6%
:, 44-7%
9.4%
8.6%
0,05 ppm
Recovered Solvent
°C
154
158
160
161
162.5
164
166
168
170
173
174
176
178
182
184
15.3
30.5
0.3
33.9
14.3%
18.4%
45.5%
10.9%
10.9%
56
-------
Operating Labor
The amount of labor required to operate the carbon adsorption unit
designed by VIC Manufacturing was estimated on the basis of TRW operating
data. For the purpose of comparison with the optimization studies, the
estimated labor requirements were broken into the following four categories
1) ,Start-up
2) Filter cleaning
3) Shutdown
4) Miscellaneous
The labor requirement is of a non-professional nature; however, some
training is required. The non-optimized system operating labor is
presented in Table 6-7.
TABLE 6-7. DEMONSTRATION PROGRAM - OPERATING LABOR
Operation Labor hours/Days_
Adsorber start-up 0.25
Boiler start-up 0.25
Filter cleaning 1.50
Shutdown ' 0.50
Miscellaneous 0.50
Total 3.00 ,
Weekly total 15.00
Annual total 780.00
OPTIMIZATION STUDIES
The optimization studies ran from December 4, 1978, through March 23,
1979. The Information presented in this section refers to data collected
during that period.
Change of Filter System
The parameter studied during the change of the filter system test
was operating labor. The object of the modification was to reduce the
amount of labor required for daily operation of the system. The results
of this test are shown in Table 6-8.
57
-------
TABLE 6-8. OPTIMIZATION PROGRAM - OPERATING LABOR
Operation Labor hours/day
Adsorber start-up 0.25
Boiler start-up 0.25
Filter cleaning 0.50
Shutdown 0.50
Miscellaneous 0.50
Total 2.00
Weekly total 10.00
Annual total 520.00
Percent reduction 33%
Blower Cycle Alteration
The purpose of this test was to reduce the electricity consumption
of the carbon adsorption unit. Electricity usage was, therefore, moni-
tored as explained in Section 4. Table 6-9 represents the savings which
result from this modification.
TABLE 6-9. OPTIMIZATION PROGRAM
TASK 2 - BLOWER CYCLE ALTERATION ELECTRICITY CONSUMPTION
Electricity consumption
Week of (1979) 109 J/wk (106 Btu/wk)
January 15 4.2 (4.0)
January 29 4.3 (4.1)
February 5 4.1 (3.9)
February 19 3.8 (3.6)
February 26 3.5 (3.3)
Average 4.0 (3.8)
Pre-optimization average 4.4 (4.2)
Percent reduction 10%
58
-------
1C
TABLE 6-10. OPTIMIZATION PROGRAM
TASK 3 - ADSORPTION/DESORPTION CYCLE ALTERATION
Week of
(1979)
10
January 15
January 29
February 5
February 19
February 26
Average
Pre-optimization
Natural gas
consumption
9 J/wk (106 Btu/wk)
18.6
18.7
17.5
14.3
13.9
16.6
31.3
(17.6)
(17.7)
(16.6)
(13.5)
(13.2)
(15.7)
(29.6)
Water
consumption
103 1/wk (103 gal/wk)
6.8
6.8
6.1
4.9
4.9
5.8
9.5
(1-8)
(1.8)
(1.6)
(1.3)
(1.3)
(1.5)
(2.5)
Wastewater
to sewer
103 1/wk (103 gal/wk)
6.8
4.9
1.9
3.0
4.2
4.2
8.3
(1.8)
(1.3)
(0.5)
(0.8)
(1.1)
(1.1)
(2.2)
Average
Percent reduction
47%
40%
50%
-------
Adsorption/Desorption Cycle Alteration
As previously explained, one of the purposes of this operation
modification was to reduce the consumption of water and natural gas by
the boiler. Table 6-10 shows the reductions which result from this
operation.
It was important during this task to ensure that the adsorber
efficiency did not fall below the minimum acceptable level. Efficiency
data for this test, therefore, are presented in Table 6-11.
TABLE 6-11. OPTIMIZATION PROGRAM ADSORBER EFFICIENCY DATA
TASK 3 - ADSORPTION/DESORPTION CYCLE ALTERATION
December 4, 1978 - January 12, 1979
Solvent into adsorber - 1 (gal) 5016 (1325)
Solvent emissions from adsorber - 1 (gal) 208 (55)
Solvent recovered - 1 (gal) 3721 (983)
Method 1 efficiency 96%
Method 2 efficiency 74%
Carbon Bed Depth Adjustment
Two breakthrough tests were conducted to determine the depth of the
mass transfer zone in the carbon beds. The first test was conducted
during the week of January 22, 1979, and the second during the week of
February 12, 1979. The results of both tests are presented in Table 6-
12.
TABLE 6-12. OPTIMIZATION PROGRAM BREAKTHROUGH ANALYSIS RESULTS
Test 1 - January 22-24. 1979
Total solvent into adsorber - 1 (gal) 587 (155)
Average solvent recovered at breakthrough -
1 (gal) 227 (60)
Total solvent emissions from adsorber - 1 (gal) 121 (32)
Total solvent recovered -> 1 (gal) 450 (119)
Total cycles adsorbed 32
Cycles adsorbed at breakthrough 14
Cycles adsorbed at saturation 25
Calculated MTZ depth - m (in) 0.7 (29.6)
(continued)
60
-------
Test 2 - February 12-15, 1979
Total solvent into adsorber - 1 (gal)
Average solvent recovered at breakthrough -
1 (gal)
Total solvent emissions from adsorber - 1 (gal)
Total solvent recovered - 1 (gal)
Total cycles adsorbed
Cycles adsorbed at breakthrough
Cycles adsorbed at saturation
Calculated MTZ depth - m (in)
927
111
416
447
42
14
25
0.7
(245)
(60)
(110)
(118)
(29.6)
Desorption Alteration
As described in Section 5, the steam cycle was changed during this
test. Adsorber efficiency'was monitored throughout the duration of the
alterations to determine whether or not a reduction had occurred. As
explained, adsorber efficiency was reduced and the steam cycle was re-
turned to 60 min. The results of the 45 min and 50 min tests are shown
in Table 6-13. In addition, the natural gas and water consumption rates
for the tests are presented in Table 6-14. It must be noted that these
gas and water consumption figures show reductions over the pre-optimiza-
tion rates and the Task 3 rates. Due to the decrease in adsorber effi-
ciency, however, these are not representative of the optimized system.
Air Cooler Reduction Test
During the period of this test, the inlet air stream and carbon bed
temperatures were closely monitored to determine if the recommended
maximum of 57°C (135°F) was exceeded. Table 6-15 lists the maximum
temperature recorded during each day of the test.
Optimized System
Presented in Tables 6-16 and 6-17 are all continuous data collected
during the optimization program. Table 6-18 is a summary of adsorber
efficiency data collected during the period when the system was operated
at the optimum level. Table 6-19 presents the weekly utilities consump-
tion summary for the optimized system.
Solvent analyses were performed four times during the optimization
study. The results of these analyses are presented in Table 6-20.
SPECIAL TESTS
Carbon Analysis
Carbon samples were collected four times during the test program
and analyzed for carbon activity and retentivity. Carbon activity was
measured using perchloroethylene adsorption at 21°C (70°F) and carbon
61
-------
TABLE 6-13. OPTIMIZATION PROGRAM ADSORBER EFFICIENCY DATA
TASK 5 - DESORPTION ALTERATION
March 6. 1979 - March 23, 1979
45-Min steam cycle
Solvent into adsorber - 1 (gal) 1094 (289)
Solvent emission from adsorber - 1 (gal) 79 (21)
Solvent recovered - 1 (gal) 859 (227)
Method 1 efficiency 93%
Method 2 efficiency 79%
50-Min steam cycle
Solvent into adsorber - 1 (gal) 2010 (531)
Solvent emissions from adsorber - 1 (gal) 189 (50)
Solvent recovered - 1 (gal) 1609 (425)
Method 1 efficiency 91%
Method 2 efficiency 80%
62
-------
CTl
CO
TABLE 6-14. OPTIMIZATION PROGRAM
TASK 5 - DESORPTION ALTERATION
Week of
(1979)
March 5
March 12
March 19
Average
Pre-optimization
Natural gas
consumption
109 J/wk (106 Btu/wk)
14.1
11.1
14.8
13.3
31.3
(13.4)
(10.5)
(14.0)
(12.6)
(29.6)
Water
consumption
103 l/'wk (103 gal/wk),.
4.9
4.2
4.9
4.7
9.5
(1-3)
(1.1)
(1-3)
(1.2)
(2.5)
Wastewater
to sewer
103 1/wk (103 gal/wk)
3.0
1.9
2.6
2.5
8.3
(0.8)
(0.5)
(0.7)
(0.7)
(2.2)
average
Percent reduction
over pre-optimized
system
Task 3 average
Percent reduction over
task 3
57%
16.6
(15.7)
20%
51%
5.8
(1.5)
20%
69%
4.2
(1.1)
38%
-------
TABLE 6-15 OPTIMIZATION - TASK 6
AIR COOLER REDUCTION TEST
Water flow through
Date
(1979)
March 9
March 12
March 13
March 14
March 15
March 19
March 20
March 21
March 22
March 23
air cooler
(I/day) (gal/day)
678
568
598
568
265
231
49
0
0
0
(179)
(150)
(158)
(150)
(70)
(61)
(13)
(0)
(0)
(0)
Dai ly maximum
inlet temperature
( C) V ' }
35
35
33
36
37
34
35
47
51
50
(95)
(95)
(91)
(97)
(98)
(93)
(95)
(117)
(124)
(122)
*Number of readings exceeding 57°C (135°F) = 0.
64
-------
TABLE 6-16. SUMMARY OF DRY CLEANING CARBON ADSORPTION OPTIMIZATION PROGRAM
OPERATING DATA (METRIC UNITS)
CT)
cn
Julian
date
(1978)
333
339
340
341
342
345
346
347
348
349
353
354
197?
003
004
005
008
009
010
on
012
015
016
017
013
019
022*
023*
024*
025
026
029
030
031
032
033
Electrical
consumption
of system
kWh
207
267
311
311
266
261
312
217
265
173
223
265
220
215
265
353
218
261
203
217
216
262
260
215
219
221
172
171
263
260
264
259
260
171
262
Natural gas
consumption
of boiler
ft3
210
99
102
99
91
93
99
93
105
93
96
93
108
93
99
93
102
93
93
91
109
112
106
122
116
0
0
184
93
96
102
88
102
99
96
Water
consumption
of boiler
(1)
2687
1893
1552
1207
1363
1211
1476
1325
1628
1363
1552
1741
1476
1237
1287
1325
1400
1211
1476
1325
1400
1249
1249
1400
1363
0
0
2309
1211
1363
1249
1173
1287
1249
1211
Decanted
water to
sewer
(1)
2650
757
1136
757
757
1136
757
1136
757
1136
757
1136
1136
757
1136
757
757
1136
757
757
757
757
757
757
757
0
0
2271
379
757
757
757
757
757
379
Water flow
to tower
cooler
(1)
3179
3142
4883
4883
4466
4883
4504
4542
4050
3104
2157
4315
3709
4921
3671
3407
2460
3104
6737
3407
2990
4012
4126
3671
3369
2339
2729
4201
4050
4542
4277
4466
1438
2271
4693
Water flow
to
condenser
(1)
79107
133939
147237
143S30
130960
1271CO
1 36260
117710
120740
87606
215745
123310
93110
127550
117710
162380
113550
100680
91980
113930
126040
140420
133530
126040
103330
107120
96900
110900
129070
136640
140420
162760
140045
114310
140420
Solvent
Introduced
adsorber
(1)
270
280
241
244
212
270
284
226
270
234
147
201
123
180
241
310
288
259
241
244
226
292
342
270
216
226
270
90
306
292
280
292
306
230
259
Solvent
air emissions
from adsorber
24.1
6.1
15.5
11.9
2.5
6.5
13.7
10.1
12.5
5.3
4.0
7,2
2.2
3.2
5.8
23.0
15.1
14.1
7.5
9.0
11.1
17.6
25.6
16.5
9.7
6.5
76.2
40.3
16,9
14.3
10.5
15.9
36.7
19.4
14.1
Recovered
solvent
(1)
189
174
159
193
216
189
201
220
220
235
167
144
144
139
155
233
243
224
238
229
229
224
243
262
257
0
0
449
267
265
265
269
299
227
227
NO. dry
cleaning
cycl es
14
15
15
13
12
13
15
12
13
12
3
12
7
11
12
16
13
14
13
12
13
16
17
13
12
13
14
5
14
15
13
15
15
12
15
I Emissions
Recovered reduction
.75 95.2
.83 96.3
.89 96.7
.90 97.9
.87 94.9
.90 94.0
.83 87.0
.94 92.9
(continued)
-------
TABLE 6-16. (continued)
cr>
en
Julian
date
(1978)
036
037
038
039
040
043*
044*
045*
046*
047
051
052
053
054
057
058
059
060
064
065
066
067
068
071
072
073
074
078
079
080
081
082
Electrical
consumption
of system
kWh
168
259
258
259
211
169
220
218
123
312
218
307
212
308
218
257
216
264
211
212
256
216
214
212
215
263
213
218
219
264
125
211
Natural gas
consumption
of boiler
ft3
91
96
91
88
91
0
0
0
263
93
91
96
96
88
93
93
96
79
91
71
71
71
65
62
76
74
76
82
76
82
68
76
Water
consumption
of boiler
(1)
1249
1325
1022
1173
1136
0
0
0
3225
1211
1249
1173
1211
1136
1211
1211
1173
1363
1249
871
1022
984
824
946
946
984
1211
795
946
1098
871
1022
Decanted
water to
sewer
(1)
757
1136
757
379
1136
0
0
0
3028
757
757
757
757
379
757
757
757
757
757
379
757
379
757
379
379
379
757
379
757
379
757
379
Water flow
to tower
cooler
(1)
4769
5261
2385
4315
2233
1211
1060
757
2271
1855
1476
1476
1590
1703
1623
2309
1703
1249
3066
2914
3104
1703
1855
2006
1514
1893
1514
871
1022
984
946
1590
Water flow
to
condenser
m
1 1 1 280
137400
149510
134370
106360
88191
85920
102195
88948
128690
1 04088
142695
115064
128312
113550
134368
101817
114307
119228
102195
123013
96139
167335
114686
119606
115064
118092
108630
97275
126040
77590
114690
Solvent
Introduced
adsorber
OJ
223
288
288
288
266
310
306
313
0
295
262
389
356
367
377
356
294
292
252
310
302
205
294
292
274
266
256
277
230
288
198
220
Solvent
air emissions
from adsorber
(1!
9.3
8.6
8.3
11.5
8.6
11.5
105.7
298.8
0
2.5
5.0
21.9
22.6
30.2
17.3
20.5
9.3
9.7
10.1
6.8
41.5
4.0
8.6
27.0
20.5
18.7
23.4
12.9
11.5
38.9
22.3
40.7
Recovered
solvent
(1)
227
223
227
227
250
0
0
0
448
213
244
254
278
269
279
259
270
252
237
224
225
210
239
IK'S
1 O-J
255
237
208
220
?!d
C 1 *t
167
145
162
No. dry
cleaning
cycles
(per day)
12
13
14
13
12
13
14
15
0
13
12
19
16
17
14
15
14
13
11
14
15
10
12
13
14
13
13
T T
1 1
15
10
12
J Emissions
Recovered reduction
(weekly) (weekly)
.85 96.6
.54 65.8
.76 94.2
.80 95.7
.83 95.8
.81 91.8
•75 89.6
S
*Dreakthrough test.
-------
TABLE 6-17. SUMMARY OF DRY CLEANING CARBON ADSORPTION OPTIMIZATION PROGRAM
OPERATING DATA (ENGLISH UNITS)
Julian
date
(1978)
338
339
340
341
342
345
346
347
348
349
353
354
1979
~00l
004
005
008
009
010
Oil
012
015
016
017
018
019
022*
023*
024*
025
026
029
030
031
032
033
036
037
038
039
040
Electrical
consumption
of system
kWh
207
267
311
311
266
261
312
217
265
173
223
265
220
215
265
353
218
261
203
217
216
262
260
215
219
221
172
171
263
260
264
259
260
171
262
168
259
258
259
211
Natural gas
consumption
of boiler
«3
7400
3500
3600
3500
3200
3300
3500
3300
3700
3300
3400
3300
3800
3300
3500
3300
3600
3300
3300
3200
3300
3400
3200
3700
3500
0
0
6500
3300
3400
3600
3100
3600
3500
3400
3200
3400
3200
3100
3200
water
consumption
of boiler
(oal)
710
500
410
340
360
320
390
350
430
360
410
460
390
340
340
350
370
320
390
350
370
330
330
370
360
0
0
610
320
360
330
310
340
330
320
330
350
270
310
300
Decanted
water to
sewer
(gal)
700
200
300
200
200
300
200
300
200
300
200
300
300
200
300
200
200
300
200
200
200
200
200
200
200
0
0
600
100
200
200
200
200
200
100
200
300
200
100
300
Water flow
to tower
cooler
(gal)
840
830
1290
1290
1180
1290
1190
1200
1070
820
570
1140
980
1300
970
900
650
820
1780
900
790
1060
1090
970
890
750
721
1110
1070
1200
1130
1180
380
600
1240
1260
1390
630
1140
590
Water flow
to
condenser
(gal)
20900
35400
38900
38000
34600
33600
36000
31100
31900
23000
57000
33900
24600
33700
31100
42900
30000
26600
24300
30100
33300
37100
36600
33300
27300
28300
25600
29300
34100
36100
37100
43000
37000
30200
37100
29400
36300
39500
35500
28100
Solvent
Introduced
adsorber
(gal)
71
74
64
64
56
71
75
60
71
62
39
53
32
48
64
82
76
68
64
64
60
77
90
71
57
60
71
24
81
77
74
77
81
61
68
59
76
76
76
70
Solvent
air emissions
from adsorber
(gal)
6.3
1.6
4.1
3.1
0.7
1.7
3.6
2.7
3.3
1.4
1.1
1.9
0.6
0.8
1.5
6.1
4.0
3.7
2.0
2.4
3.0
4.6
6.8
4.4
2.6
1.7
20.1
10.6
4.5
3.8
2.8
4.2
9.7
5.1
3.7
2.5
2.3
2.2
3.0
2.3
Recovered
solvent
(gal)
50
46
42
51
57
50
53
58
58
62
44
38
38
50
41
62
64
59
63
61
61
59
64
69
68
0
0
118
71
70
70
71
79
60
60
60
59
60
60
66
No. dry
cleaning
cycl es
(per day)
14
15
15
13
12
13
15
12
13
12
8
12
7
11
12
16
13
14
13
12
13
16
17
13
12
13
14
5
14
15
13
15
15
12
15
12
13
14
13
12
X Emissions
Recovered reduction
(weekly) (weekly)
.75 95.2
.83 96.3
.89 96.7
.90 97.9
.87 94.9
.90 94.0
.83 87.0
.94 92.9
.85 96.6
(continued)
-------
TABLE. 6-17. (continued)
en
oo
Julian
date
(1978)
043*
044*
W*T*t
045*
046*
047
051
\J*J 1
052
V Jlpp
053
054
ncy
v*J t
05H
\J*JO
059
U J?
060
Ofi4
wU*t
065
ofifi
l/Uu
067
vU /
068
071
072
073
074
078
079
080
081
082
Electrical
consumption
of system
kWh
169
220
218
123
312
218
307
212
308
218
257
216
264
211
212
256
216
214
212
215
263
213
218
219
264
125
211
Natural gas
consumption
of boiler
ft3
0
0
0
9300
3300
3200
3400
3400
3100
3300
3300
3400
2800
3200
2500
2500
2500
2300
2200
2700
2600
2700
2900
2700
2900
2400
2700
Water Decanted
consumption water to
•W BW
0
0
0
860
320
330
310
320
300
320
320
310
360
330
230
270
260
220
250
250
260
320
210
250
290
230
270
0
0
0
800
200
200
200
200
100
200
200
200
200
200
100
200
100
200
100
100
100
200
100
200
100
200
100
Water flow
to tower
cooler
(gal)
320 .
' 280
200
600
490
390
390
420
450
430
610
450
330
810
770
820
450
490
530
400
500
400
230
270
260
250
420
Water flow
to
condenser
(9al)
23300
22700
27000
23500
34000
27500
37700
30400
33900
30000
35500
26900
30200
31500
27000
32500
25400
31000
30300
31600
30400
31200
28700
25700
33300
20500
30300
Solvent
Introduced
adsorber
MgaD
82
81
83
0
78
69
103
94
97
100
94
78
77
67
82
80
54
78
77
72
70
68
73
61
76
52
58
Solvent
air emissions Recovered
from adsorber solvent
(.gal) (gal)
3.0
27.9
78.9
0
0.7
1.3
5.8
6.0
8.0
4.6
5.4
2.5
2.6
2.7
1.8
11.0
1.1
2.3
7.1
5.4
5.0
6.2
3.4
3.0
10.2
5.9
10.8
0
0
0
118
56
64
67
73
71
74
68
71
67
63
59
59
55
61
48.9
67.3
62.6
55.0
58.1
56.5
44.1
38.3
42.8
No. dry
cleaning t Emissions
cycles Recovered reduction
(per day) (weekly) (weekly)
13
14
15 .54 65.8
0
13
12
19
16 .76 94.2
17
14
15
14 .80 95.7
13
11
14
15 .83 95.8
10
12
14
13 81 91.8
I J ««JI _* • I-*
14
1 *t
1?
1 O
13
11
15 .75 89.6
in
1 U
19
1 £
--------- "~
*Breakthrough test.
-------
TABLE 6-18. OPTIMIZATION PROGRAM - TASKS 2 AND 3
ADSORBER EFFICIENCY DATA
January 15, 1979 - March 6. 1979 (minus breakthrough tests)
Solvent into adsorber - 1 (gal) 7336 (1938)
Solvent emissions from adsorber - 1 (gal) 379 (100)
Solvent recovered - 1 (gal) 6462 (1707)
Method 1 efficiency 95%
Method 2 efficiency
69
-------
TABLE 6-19. OPTIMIZATION PROGRAM - WEEKLY UTILITIES CONSUMPTION
Week of Natural gas
(1979) consumption
109 J/wk (106 Btu/wk)
January 15
January 29
February 5
February 19
February 26
Average
Pre- optimization
18.6
18.7
17.5
14.3
13.9
16.6
31.3
(17.6)
(17.7)
(16.6)
(13.5)
(13.2)
(15.7)
(29.6)
Electricity
consumption
109 J/wk (106 Btu/wk)
4.2
4.3
4.1
3.8
3.5
4.0
4.4
(4.0)
(4.1)
(3.9)
(3.6)
(3.3)
(3.8)
(4.2)
Water
consumption
103 1/wk (103gal/wk)
6.8
6.1
6.1
4.9
4.9
5.8
9.5
(1.8)
(1.6)
(1.6)
(1.3)
(1.3)
(1.5)
(2.5)
Wastewater
to sewer
103 1/wk (103gal/Wk)
6.8
4.9
1.9
3.0
4.2
4.2
8.3
(1.8)
(1.3)
(0.5)
(0.8)
(1.1)
(1.1)
(2.2)
average
Percent reduction
47%
10%
40%
50%
-------
TABLE 6-20. OPTIMIZATION PROGRAM
COMPARISON OF PROCESS SOLVENT AND RECOVERED SOLVENT PROPERTIES
Week of
1978
Nov 27 Dec 4
1979
Dec 11 Feb 26
I. Distillation range difference between
process solvent and recovered solvent
(in °C) (% solvent evaporated)
0
2
5
10
20
30
40
50
60
70
75
80
90
95
end point
II. Acidity difference between process
Solvent and recovered solvent
(mg eq KOH/100 ml)
III. Kauri-Butanol value difference between
process solvent and recovered solvent
IV. Bromine number difference between process
solvent and recovered solvent
(% Br Adsorbed)
V. Flash point difference between process
solvent and recovered solvent
VI. Solvent composition difference as
determined by g,as chromatograph
(volume % by carbon fraction)
r
1 9
Cl ^
T3
$ + 15
C-ic
c}6-,
1
0.5
1
1
1
0.5
0.5
1
1
1
1
1
0
0.5
2.5
1
1
1
2
2
2
2
2
2
2
2
1.5
3
2
2
1
0.5
0
0
0.5
1
0.5
0.5
0
0
0
0.5
1
1.5
0
3
2
1
1
0
0
0.5
1
2.5
2
2
3.5
3
2
2
1.1
1.1
0
5.1
0.2
0
4.6 1.3
1.6 1-4
1.3 2.3
1.6 2.2
0.1 1.8
5.2
2.0
4.3
1.0
2.2
1.0
5.0
1.5 1.5
4.5
2.0
1.0
1.5
1.4
71
-------
retentivity was measured by air desorption at 21°C (70°F). All measure-
ments were compared to a standard consisting of carbon collected from
the beds prior to being exposed to solvent vapors.
All samples taken were judged to be acceptable in terms of activity
and retentivity. No significant changes were observed over the period
of the study, indicating that the life span of the carbon is acceptable
for use with Stoddard solvent. The results of the carbon tests are
presented in Table 6-20.
Inlet Measurement Verification
Throughout the test program, the amount of solvent entering the
adsorber was estimated by Valley personnel by weighing the clothes
before and after drying with the difference being assumed equal to the
amount of solvent evaporated. This value exceeded the inlet quantity
measured by TRW by approximately 14 percent on the average. The weight
difference method, however, included water evaporation which was not
.measured by-TRW.
In order to evaluate the validity of the TRW measurements, five
tests were run in which loads of clothes were washed in solvent only (no
water or detergent added) and dried. The weight loss measurements,
therefore, represent only solvent emissions and can be easily compared
to the TRW inlet measurements. The results of these tests are presented
in Table 6-21. The average difference between the weight loss measure-
ments for solvent-only loads and the TRW inlet measurements is 6.5
percent. This indicates that the average 14 percent difference pre-
viously mentioned is partially due to the water content of the clothes.
It must be noted that the weight loss measurements should only be
used as approximations. Variations in the tare weight of the containers
and in the weighing procedure itself result in a significant uncertainty.
Two examples of this uncertainty'are measurements made on December 27
and 29, 1978, where specific loads of clothes are reported to have
weighed 6.8 and 17 kg (15 and 38 Tbs) more, respectively, after cleaning
than they did before dry cleaning. Although these are isolated cases,
they do illustrate the problems associated with making this type of
measurement.
72
-------
TABLE 6-21. DEMONSTRATION PROGRAM - CARBON TEST RESULTS
Sample
date
August 7, 1978
October 3, 1978
November 16, 1978
February 7, 1979
Sample
Standard
Top
Middle
Bottom
Standard
Top
Middle
Bottom
Standard
Top
Middle
Bottom
Standard
Top
Middle
Bottom
Activity
69.6%
61 . 3%
54.7%
53.5%
72.7%
51.3%
42.9%
44.7%
69.4%
67.2%
74.4%
69.3%
68.9%
46.9%
66.1%
71.6%
Retentivity
45.5%
45.7%
22.2%
23.7%
48.2%
22.9%
22.0%
23.1%
45.7%
38.5%
42.6%
40.3%
45.5%
22.6%
38.7%
42.6%
Density
0.485 g/crn^
0.584 g/cm^
0.541 g/cm~
0.568 g/crrr
0.479 g/cm^
0.483 g/cm^
0.448 g/cm^
0.515 g/crrT
0.469 g/cm~
0.537 g/cm^
0.466 g/ Gnu
0.485 g/cnr
73
-------
TABLE 6-22. WEIGHT LOSS VERSUS SOLVENT INLET MEASUREMENTS
Weight loss FID inlet %
Date measurement measurement Difference
(1979) kg (Ib) kg (15)
January 17 34-9 (77) 33.1 (93) 5.2
January 25 37.6 (83) 36.7 (81) 2.4
January 30 35.4 (78)" 31.3 (69) 11.6
January 31 32.7 (72) 33.1 (73) 1.2
February 28 32.7 (72) 36.7 (81) 12.2
Average 6.5
74
-------
SECTION 7
ERROR ANALYSIS
In order to effectively evaluate the technical and economic feasi-
bility of using carbon adsorption as a hydrocarbon emissions control
technique, it is necessary to determine the error band(s) associated
with each relevant operating parameter.
This is accomplished by using the reported accuracies of each
measurement device (as given by the corresponding manufacturer or esti-
mated from the literature) and from these accuracies, calculating the
maximum expected error, assuming all the associated errors are in the
same direction.
Calculation of the maximum expected error for each process opera-
ting parameter (such as mass flow rate of hydrocarbons into the carbon
adsorption unit) requires that all component errors be taken into
account. Thus, for example, in the case of inlet hydrocarbon mass flow
rate, the following elements affect the overall.error: inlet hydro-
carbon concentration measurement errors, errors related to measurement
of the inlet flow rate (composed of the measurement device error and
errors associated with calibration of the measurement device; errors
associated with calibration of zero and span gas; errors associated with
tentperature measurement of the inlet gas stream to carbon adsorber;
and errors associated with recorders used (both the strip chart recorder
and the data logger). A table (Table 7-1) of each applicable process
operating parameter and the component errors making up the maximum
expected error is given; in addition, the maximum expected error for
each process operating parameter is also given (Table 7-2).
For purposes of calculating the maximum expected error of the mass
flow rate of hydrocarbons into and out of the carbon adsorber, the
following mean hydrocarbon concentrations (based on weighted averages
obtained during each respective test period) were used:
1. Mean hydrocarbon concentration into the carbon adsorber (both
during the Demonstration test and Optimization test) - 2,100
ppm.
2. Mean hydrocarbon concentration out of the carbon adsorber
(during the Demonstration test) - 15 ppm.
75
-------
TABLE 7-1. COMPONENT ERRORS COMPRISING EACH PROCESS OPERATING PARAMETER
Process operating parameter
Component error
Rated
accuracy
Reference
Mass flow rate of hydrocarbons
cr>
Boiler operating costs
Water consumption of
condensers
Electrical consumption of
carbon adsorption system
Solvent recovery rate
Operating labor
1) Hydrocarbon concentration ±1% f.s.
a. measurement device +1% f.s.
b. instrument calibration ±2%
2) Inlet flow
a. measurement device ±2%
b. instrument calibration +10%
3) Inlet temperature +1%
4) Recorder
a. strip chart recorder ±0.2% f.s.
b. data logger ±0.3%
1) Natural gas flow rate to boiler ±0.8%
2) Water consumption of boiler ±1%
1) Water usage of system conden- ±1%
sers
1) Electric power requirements of ±0.5%
system
1) Measured solvent during Demon- ±15%
strati on test
2) Solvent meter during Optimize- ±1%
tion test
1) Labor necessary to operate and ±20%
maintain carbon adsorption
system
Beckman Instruments
Beckman Instruments
Air Products
Thermo Systems
*
Hewlett-Packard
Fluke Manufacturing
Public Service Co.
of NC
Durham City (NC)
Water Department
Durham City (NC)
Water Department
Duke Power Company
of NC
Estimated
Estimated
Estimated
*"Stack Sampling Technical Information, A Collection of Monographs and Papers (Volume II)", EPA-450/
2-78-042b, U.S., EPA. Research Triangle Park, NC, October 1978.
+Leland, B. J. Correction of S-Type Pitot-static Tube Coefficients when used for Isokinetic Sampling
from Stationary Sources. Environ. Sci. and Tech., 11:694, 1977.
-------
TABLE 7-2. MAXIMUM EXPECTED ERROR FOR EACH
PROCESS OPERATING PARAMETER
Process operating parameter
Maximum expected
error
Mass flow rate of hydrocarbons into the carbon
adsorber (both during Demonstration test and
Optimization test)
Mass flow rate of hydrocarbons out of adsorber
(during Demonstration test)
Mass flow rate of hydrocarbons out of carbon
adsorber (during Optimization test)
Solvent recovery efficiency (during Demonstration test)
Solvent recovery efficiency (during Optimization test)
Steam utilization of carbon adsorption system
Water consumption of condensers
Quantity of recovered solvent (during Demonstration
test)
Quantity of recovered solvent (during Optimization
test)
Operating labor
-20% to +23%
-79% to +126%
-23% to +31%
-23% to +41%
-21% to +24%
+2%
±1%
±15%
±1%
+20%
77
-------
3. Mean hydrocarbon concentration out of the carbon adsorber
(during the Optimization test) - 100 ppm.
The maximum expected error in the amount of labor necessary for the
proper operation and maintenance of the carbon adsorption system is
estimated to be 20 percent. However, it should be noted that this
operating parameter varies considerably on a day-to-day basis. This is
due to some maintenance procedures required on an "as needed" basis
(such as cleaning of the adsorption system filter).
A sample calculation employed to determine the maximum expected
error in the inlet mass rate of hydrocarbons is given in Appendix A.
In the mass flow rate calculations of hydrocarbons into and out of
the carbon adsorption system, it is assumed that the gas flow rate did
not vary across the carbon adsorber. Thus, when determining the maximum
expected error in the solvent removal efficiency of the carbon adsorp-
tion system, the errors associated with the flow rate would cancel.
With this assumption, the maximum expected range of the emission reduc-
tion efficiency is calculated to be 98.4 percent to 99.8 percent for the
Demonstration test and 93.9 percent to 96.3 percent for the Optimization
study.
78
-------
REFERENCES
1. Telecon. Nunn, A. B. Methods of Calculating the Mass Transfer
Zone Depth in a carbon Bed. TRW Environmental Engineering Division,
with Don Lee, VIC Manufacturing Co., February 22, 1979.
2. Telecon. Lutz, S. J. Inlet Gas Temperatures at Which Carbon
Oxidation Begins to Occur. TRW Environmental Engineering Division,
with J. W. Barber, VIC Manufacturing Co., September 5, 1978.
79
-------
APPENDIX A
SAMPLE CALCULATION TO DETERMINE MAXIMUM EXPECTED ERROR
BAND IN THE INLET MASS RATE OF HYDROCARBONS
RELEVANT COMPONENT ERRORS
1) Hydrocarbon analyzer: +1 percent of full scale.
2) Hydrocarbon analyzer calibration gas: +2 percent.
3) Flow rate measurement device: +2 percent.
4) Flow rate measurement device calibration
(velocity traverse): +10 percent.
5) Inlet temperature measurement (thermocouple): +1 percent.
6) Strip chart recorder: +0.2 percent of full scale.
7) Data logger: +0.3 percent.
Full Scale calibration gas: 11,000 ppm
Expected component error from hydrocarbon analyzer (assuming average
inlet concentration of 2,100 ppm):
(0.01) (11.000 ppm) _ ,y
2,100 ppm - '"
Expected component error from strip chart recorder (assuming average
inlet concentration of 2,100 ppm):
(0.002) (11,000) _ ,,„,
2,100 ppm " - h
Low range expected error in inlet mass rate of hydrocarbons:
1 - {(.95) (.98) (.98) (.90) (.99) (.99) (.997)} = 20 percent
Upper range expected error in inlet mass rate of hydrocarbons:
1 - {(1.05) (1.02) (1.02) (1.10) (1.01) (1.01) (1.003)} = 23 percent.
80
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO. 2.
EPA-600/2-80-145
4. TITLE AND SUBTITLE
Demonstration of Carbon Adsorption Technology for
Petroleum Dry Cleaning Plants
7. AUTHOR(S)
S. J. Lutz, S. W. Mulligan, A. B. Nunn
& PERFORMING ORGANIZATION NAME AND ADDRESS
TRW, Inc.
Environmental Engineering Div.
P. 0. Box 13000
Research Triangle Park, N.C. 27709
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
I Cincinnati, Ohio 45268
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
.TTTNF, 1Q8D TSRTrQvjn DATE
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
B118/C33B1B
11. CONTRACT/GRANT NO.
68-03-^2560
13. TYPE OF REPORT AND PERIOD COVERED I
Task Final, 10/77 - 4/79
14. SPONSORING AGENCY CODE
EPA/600/12
115. SUPPLEMENTARY NOTES
J IERL-Ci project officer for the report is R. J. Turner - (513) 684-4481
16. ABSTRACT
A carbon adsorption system was designed and installed on the exhaust
outlet from a dryer at an industrial dry cleaning plant utilizing Stoddard
solvent for cleaning purposes. Selected design and operating parameters
were varied to determine their effect on annualized operating costs and
system performance. After optimization, the carbon adsorber achieved a
demonstrated efficiency in reducing hydrocarbon emissions of 95 percent.
J17. KEY WORDS AND DOCUMENT ANALYSIS
ja- DESCRIPTORS
r
18. DISTRIBUTION STATEMENT
Release to Public
b.lDENTIFIERS/OPEN ENDED TERMS
Carbon adsorption
Vapor - phase adsorption
Industrial dry cleaning
Solvent recovery
19. SECURITY CLASS (This Report)
Unclassified
20. SECURITY CLASS (This page)
Unclassified
c. COSATI Field/Group 1
13B 1
21. NO. OF PAGES I
91
22. PRICE
EPA Perm 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
U.S. GOVERNMENT PRINTING OFFICE: 1"81--657-165/0013
81
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