United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EMB Report 80-DRY-9
October 1980
Air
Petroleum Dry Cleaners
Centrifugal Separator

Emission Test Report
Cadet Cleaners
Toronto, Canada

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SOLVENT RECOVERY AND EMISSION CONTROL
    PETROLEUM DRY CLEANING INDUSTRY
         CADET CLEANERS PLANT
       Toronto, Ontario, Canada
           Prepared for the
 U.S. Environmental Protection Agency
      Emission Measurement Branch
 Research Triangle Park, N. C.   27711
              Prepared by
Clayton Environmental Consultants, Inc
         25711 Southfield Road
       Southfield, Michigan  48075
        EMB Report No. 80-DRY-9
           Work Assignment  38
        Contract No. 68-02-2817

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                 TABLE OF CONTENTS




                                                   Page




List of Tables                                       i




List of Figures                                     ii




1.0     Introduction                                 1




2.0     Summary and Discussion of Results            2




3.0     Process Description                         11




4.0     Location of Sampling Points                 12




5.0     Sampling and Analytical Procedures          14






APPENDICES




A.      Esso Chemical Sheet




B.      ASTM Methods




        B-l.   D 322 - 67




        B-2.   D 240 - 76




        B-3.   D 96 - 73 and Modifications



C.      Laboratory Analysis

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                     LIST OF TABLES

Table                                               Page
 2.1    Results of Filter and Dried Muck              3
        Analyses

 2.2    Petroleum Solvent Decanted Before             6
        Distillation

 2.3    Results of Liquid Sample Analyses             8

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                  LIST OF FIGURES

Figure                                            Page

 4.1    Plan view of filtration equipment          13
        and location of sampling points
                          11

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                      1.0  INTRODUCTION



      The United States Environmental Protection Agency

(EPA)  retained Clayton Environmental Consultants, Inc.  to

evaluate the performance of a centrifugal separator at  the

Cadet Cleaners plant in Toronto, Ontario, Canada. The

objective of this study was to determine the total uncon-

trolled solvent loss from this plant (provided by TRW,

Inc.)  and to evaluate the performance of the centrifugal

separator as an emission control technique.  The results of

this study will be used in research and development efforts

for supporting New Source Performance Standards in the

petroleum dry cleaning industry.  This study was commis-

sioned as Project No. 80-DRY-9, Contract No. 68-02-2817,

Work Assignment 38.

      The field sampling program, conducted July 9 through

11, 1980, was slightly modified after inception and in-

cluded the following:

       (1)       Multiple soap and rinse filter muck samples
                acquired from diatomaceous earth filters
                for petroleum solvent loss determinations;

       (2)       Multiple dried muck samples acquired from a
                centrifugal separator after extraction  for
                petroleum solvent loss determinations;  and,

       (3)       Duplicate samples from the vacuum petroleum
                still bottom wastes, reclaimed distilled
                solvents, and a single sample of virgin
                petroleum solvent acquired for determina-
                tion of Btu content and inerts.
                       - 1 -

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           2.0  SUMMARY AND DISCUSSION OF RESULTS

     The results of the sample solvent recovery and heat of

combustion analyses are presented in Tables 2.1 and 2.3,

respectively.

     Table 2.1 presents the quantity of solvent (as a

percent by weight) retained by the filter muck samples.

These samples were collected from the East and West domes-

tic soap and rinse filtered mucks, an industrial filtered

muck, both before centrifuqation  (after 24 hours of

settling), and from the combined soap and rinse filter

mucks after centrifugation.  The efficiency of the

centrifugal separation system also appears.  The solvent

retained, as percent by weight, was calculated using the

following equation:

Solvent Retained  =  (milliliters of diluent) (SpGr)   (D)  1QQ
                            weight of aliquot

     where:SpGr   = specific gravity of solvent  (60/60F)

                   = 0.7857 (Appendix A)

              D   = density of water, g/ml

                   = 1.0

     The efficiency of the centrifugal separation system

 (quantity of solvent removed, as percent by weight, during

the solvent recovery process) was calculated using the

following equation:

     Efficiency   = SSF - SDM    x 1QO

                     SSF

     where: SSF   = % solvent by weight retained by soap

                   filter.

            SDM   = % solvent by weight retained by dried

                   muck.

                       - 2 -

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                        TABLE 2.1.   RESULTS OF FILTER AND DRIED MUCK ANALYSES
Sampling
Date and Sam
Time
7/09/80 West
PM West
7/10/80 East
AM East
7/10/80 West
PM West
7/11/80 East
AM
7/11/80 West
PM West
(% by Weight)
p e Before Centrifugation
(After 24 hr settling)
soap 47 . 1
rinse 47.6
soap 54.9
rinse 52.3
soap 48.7
rinse 41.3
soap 52.3

soap 51.3
rinse 47.1
Average 49.2
7/11/80 Industrial 52.3
AM

After Centrifugation
34.0
34.0
34.5
34.5
31.4
31.4
38.2

30.9
30.9
33.3
38.2

Extraction
Efficiency
(% by Weight)
27.8
28.6
37.1
34.0
35.5
24.0
27.0

39.8
34.4
32.0
27.0

Facility: Cadet Cleaners, Toronto, Ontario, Canada.
                                         -  3  -

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     The solvent retained by the filter muck samples
collected from the domestic soap and rinse filters of the
East and West filtering systems (before centrifugation)
ranged from 41.3 to 54.9-percent,  averaging 49.2-percent.
The single industrial filter retained 52.3-percent solvent
by weight.  The solvent retained by the dried muck samples,
after centrifugation, ranged from 30.9 to 38.2-percent,
averaging 33.3-percent.  Laboratory data appears in Appen-
dix C.
     The relative difference in solvent content between  the
domestic soap and rinse filter muck samples seems to
generally be a decreasing function.  In theory, it is
plausible that the industrial and soap diatomaceous earth
filters separate a coarser dirt particle or a more sponge-
like particle than do the rinse filters and thus, retain
more solvent.  However, there are not sufficient data sets
to refute or corroborate this theory.
     The centrifugal separator reclaimed an average of
32.0-percent of the solvent in the filters.  Therefore,  the
solvent loss from the plant is reduced by using the cen-
trifugal separator.
     The efficiency of the centrifugal separator seems to
depend on the particle size of the dirt concentration,
solvent retention of the filter mucks to be extracted, and
average rotational speed which the separator ultimately
achieves during extraction.  The efficiency of the sep-
arator does not seem to depend on the condition of the
                       - 4 -

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cloth bag used to retain the dried muck for  disposal.   This



was evidenced by the fact that the cloth bag was  washed and



cleaned prior to the last extraction sampled, yet no sig-



nificant improvement in efficiency was  displayed.



      Table 2.2 displays the amounts of petroleum solvent



decanted from each filter muck sample (before centrifuga-



tion).  Each sample was decanted twice  before the lab-



oratory distillation procedure began.  The  first  decanting



occurred in the field after 24 hours or less of settling.



Due to the hazardous/flammable nature of the solvent,  field



decanting was necessary to reduce the overall volume of



solvent so the samples could be shipped by  land carrier



through customs.



      The field decanting removed most  of the solvent above



the settled filter muck leaving only a  thin  layer to keep



the filter muck immersed and fluidized  for  later  laboratory



analysis.  This layer of solvent was used by the  laboratory



to mix the samples to simulate the 24-hour  settling period



prior to distillation analysis which could not be achieved



in the field.  This thin layer of solvent was to be de-



canted off by the laboratory after the  24-hour settling



period.




      Although five filter muck samples had no excess



solvent to be decanted after the settling period, the




solvent retained by the filter muck dovetailed with those



which did have decantable volumes to within 10.8 and 12.5-



percent of the mean and average values, respectively.
                       - 5 -

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              TABLE 2.2.  PETROLEUM SOLVENT DECANTED BEFORE ANALYSES
Sampling
Date and
Time
7/9
PM
7/10
AM
7/10
PM
7/11
AM
7/11
PM
7/11
AM

Sample

West soap
West rinse
East soap
East rinse
West soap
West rinse
East soap

West soap
West rinse
Industrial

Field
Decantation
ml
76
168
120
189
150
120
145

93
98
158

Laboratory
Decantation
ml
28
0
0
0
0
0
27

92
32
65

Total
Volume
ml
104
168
120
189
150
120
172

185
130
223

Facility: Cadet Cleaners, Toronto, Ontario, Canada.
                                       -  6  -

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      Table 2.3 presents the heat of combustion of the



liquid samples, expressed as British Thermal Units per



gallon of solvent (Btu/gal), and the percent inerts.



      The analyzed heat of combustion of the liquid samples



ranged from 124,900 to 130,400 Btu/gal,  with a mean of



128,900 Btu/gal.  The still bottom waste samples averaged



130,400 Btu/gal and the reclaimed solvent averaged 127,000



Btu/gal.  The still bottom waste has a higher heat value



possibly due to fiber resins and organic constituents



contained therein.  It may be feasible to use the still



bottom wastes, now being dumped into the city sewer system,



as a supplemental fuel and/or boiler fuel additive.



      The liquid samples were analyzed for percent inerts.



Due to sample contamination of the redistilled and virgin



solvent samples, only the still bottom waste samples were



analyzed and averaged 1.5-percent.



      No presurvey was conducted prior to the start of the



project and the scope of the project was expanded in the



field from an original total of six samples to 20 samples.



Due to the brevity of the field sampling schedule  (3 days)



and the increase in the number of samples to be collected,



it was necessary to purchase mason jars as extra sample



containers, so as not to further delay the project.



      The mason jar lids were fitted with latex rubber



gaskets to insure against leakage.  The rubber gaskets on



those sample containers that contained large quantities of



petroleum solvent reacted with the solvent which softened
                           _  -i  _

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                 TABLE 2.3.  RESULTS OF LIQUID SAMPLE ANALYSES
1980
Sample
Date
7/11
7/10
7/11

7/10
7/11


Sample
Virgin solvent
Still bottom waste - 1
Still bottom waste - 2
Average
Dry cleaning solvent - 1
Dry cleaning solvent - 2
Average
Mean
Btu/gal
129,700
130,400
130,400
130,400
129,100
124,900
127,000
128,900
%
Inerts
b
1.4
1.7
1.5
b
b
—

Facility:  Cadet Cleaners, Toronto, Ontario, Canada.
^Performed by Detroit Testing Laboratories, Inc., Oak Park, Michigan.
DSamples could not be analyzed due to contamination.

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the seal.  The rubber seal did not soften  in  any of  the



dried filter muck sample containers because of  the lack of



solvent.  The rubber seals on the containers  of the  filter



muck samples collected before centrifugation, remained



sandwiched between the lid and jar rim even after being



stored for a month prior to analysis.   Analysis was  delayed



because the glass receiver/traps  needed to measure the



diluent during distillationwere on back order by our



laboratory suppliers.



      The rubber seals of the precentrifuged  sample  con-



tainers were not appreciably altered due to the decanting



of solvent in the field; therefore any contamination would



be minimal in lieu of the mass weight  of the  filters in



comparison to the mass weight of  the gasket.  Also,  the



receiver/trap used in the analysis was only capable  of



measuring to the nearest 0.1 milliliter; therefore,  the



small amount of rubber seal which might be contained in any



of the mixed 15-grams of the filter muck aliquot would be



negligible.  The rubber seals on  the virgin and recalimed



solvent sample containers were also softened, causing



portions of the gasket to separate from the main body and



fall into the sample.  The virgin solvent developed  a very



slight orange hue even after the  pieces of the  rubber



gasket had been removed from the  samples.  These samples



were filtered before the heat content  analysis  (Btu) was



conducted.  The contamination from the latex  rubber  seal,
                        -  9  -

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which would tend to increase the heat content, would be



very small due to the minimal solubility of latex rubber in



the solvent.  The percent inerts were not obtained for



these samples since contamination is a major contributor to



inerts.
                        -  10  -

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     3.0   PROCESS  DESCRIPTION  AND OPERATIONS
To be supplied by TRW, Inc.
                   -  11  -

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              4.0  LOCATION OF SAMPLING POINTS








      All filter muck from the diatomaceous earth filters



is pumped to the centrifugal separator in varied combina-



tions for extraction.  The filter muck is delivered to  the



top of the centrifugal separator through two radial spout



arms.  The samples were collected at the discharge of these



spouts as the muck dropped into the separator.



      All dried muck samples were obtained directly from



the centrifugal separator following a 20-25 minute extrac-



tion .



      The petroleum still bottom waste samples were col-



lected from the bottom spigot of one 500-gallon per hour



Washex vacuum still.  Distilled petroleum solvent samples



were acquired from the distillation collection vessel next




to the still.



      The virgin solvent was obtained directly from the



original shipping container. Figure 4.1 presents a plan



view of the equipment and location of sampling points,  as




specified.
                        - 12 -

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J-
                                  Radial  spout arms
r
          Sewer
         trough
                                   11
                                                                          Diatomaceous Earth Filters
                                                                          No.  1-10 Domestic
                                                                          Nos.  11  - 13 Industrial
                 Leading to City Sewer System
                         N
      Figure  4.1.  Plan view of  filtration equipment and location of sampling points,

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           5.0   SAMPLING AND ANALYTICAL PROCEDURES



SAMPLING PROCEDURES




      Characteristic samples of muck were collected from



the soap and rinse filters of the East and West filter



systems. Only one industrial filter sample was collected,



due to equipment malfunctions.  The samples were collected



by diverting a portion of each filter muck discharge into  a



glass collection container which was washed clean in petro-



leum solvent and dried between each sample collection.   Up



to three equal amounts of each sample were proportionately



composited in glass sample bottles.



      A representative sample of dried muck was obtained



directly from the centrifugal separator after the comple-



tion of a 20-25 minute extraction.  Each extracted muck



sample was composed of up to four filter muck discharges.



A 1-inch (inside diameter) copper pipe was inserted into



the dried muck at random points within the separator to



ensure collection of all layers.  A 1-inch (outside dia-



meter) wooden dowel was inserted through the pipe to



deposit the sample in a glass sample bottle.  The pipe and



dowel were washed clean in petroleum solvent and dried



between each sample collection.



      Two still bottom samples were obtained from one 500-



gallon per hour vacuum still. Because of high temperatures,



the samples were initially collected in a galvanized pail,



and later poured into glass sample bottles.
                        - 14 -

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      Two distilled petroleum solvent samples  were  obtained

from the vacuum still by directly collecting  the  solvent in

qlass sample containers.

      One virgin petroleum solvent sample was  obtained in a

glass sample bottle directly from the original shipping

container.

      Therefore, at the end of the study, the  following

samples were collected:

      3 - West wash filter muck;
      3 - West rinse filter muck;
      2 - East wash filter muck;
      1 - East rinse filter muck;
      1 - industrial filter muck;
      5 - dried muck;
      2 - still bottom waste solvent;
      2 - redistilled solvent; and,
      1 - virgin petroleum solvent.

      For the July 9 and 10 samples,  the muck  levels  were

marked on the sample containers after 24 hours of settling,

and the excess solvent had been decanted off  leaving  only a

thin layer of solvent covering the muck.  The  decanting of

the solvent was conducted in-field to comply  with the

hazardous/flammable shipping regulations.  The settling

times for the July llth morning and afternoon  samples were

6-hours and 2-hours, respectively.  The volume of solvents

decanted in the field were recorded.   The containers  were

sealed and taped to prevent leakage while being shipped to

the laboratory for analyses.
                        - 15 -

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LABORATORY ANALYSIS




      All samples were checked for leakage and/or breakage



upon receipt in the laboratory and none was detected.




      Each filter muck sample was thoroughly mixed with the



remaining petroleum solvent in its container using a stain-



less steel stirring rod.  The samples were allowed to



settle for 24 hours and any excess solvent was decanted off



and the volume recorded.



      To determine the solvent content in the muck  (percent



by weight), representative portions  (approximately 15-



grams) were taken from both the filter muck and dried muck



samples with a clean glass tube.  The withdrawn portion was



weighed to the nearest 0.01-gram, transferred with dis-



tilled water to a distillation flask which was heated with



an electric heater, and analyzed by  following the refluxing



procedure as described by the American Society for Testing



and Materials  (ASTM) Method D 322-67  (Appendix B-l).  When



heating/condensation began, the system was rechecked to




ensure proper functioning.  Refluxing was allowed to pro-



ceed for 2 hours, after which, the volume of diluent was



measured at one-half hour intervals.  The analysis was



considered complete when volume changes no longer occurred



at the set refluxing temperature.
                       - 16 -

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      The still bottom wastes,  the redistilled solvent, and




the virgin solvent were analyzed for Btu content and inerts



by Detroit Testing Laboratory,  Inc.   Btu content was deter-



mined according to the procedures outlined in ASTM Method D



240-76 (Appendix B-2).  Prefiltering of the virgin and



redistilled solvent samples removed  any residue from the



samples before Btu analyses.  The procedures in ASTM Method



D 96-73 were modified in the  analysis for inerts.   Both the



method and modifications are  presented in Appendix B-3.
                       - 17 -

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