Project Summary

United States

Environmental Protection

Agency

Demonstration of Alternative

Cleaning Systems

Dean M. Menke, Gary A. Davis, Lori E. Kincaid, and Rupy Sawhney

National Risk Management

Research Laboratory

Cincinnati, OH 45268

Research and Development

This report represents the first demonstration of cleaner technologies to

support the goals of the 33/50 Program

under the EPA Cooperative Agreement

No. CR821848. It focuses on substitutes for solvent degreasing processes

that eliminate the use of chlorinated

organic solvents. The substitute technologies were 1) an aqueous wash system; 2) a no-clean technology; and 3) a

hot water wash system. Technical, environmental, and economic evaluations

were performed to determine the merits of the substitutes as they were

implemented by Calsonic Manufacturing Corporation, the project’s industry

partner. A national environmental impact evaluation was also performed to

estimate the potential impacts on the

nation’s environment if entire industrial sectors were to implement the substitutes.

The demonstration strongly supports

the implementation of the alternative

technologies. The implementation of the

cleaning process alternatives either

improved or did not affect the performance of subsequent process steps or

the quality of the products. The aqueous wash system reduced cleaning

cycle times by 50% and part reject rates

by nearly 77% with improved cleaning

characteristics. The no-clean alternative had no effect on either production

or part reject rates. The substitutes significantly reduced the quantity of toxic

chemicals used and released. The traditional processes released 1,1,1-

trichloroethane (TCA) to the air, as well

as generated a TCA hazardous waste

stream; the substitutes generate either

a non-hazardous wastewater discharge

(aqueous and hot water wash systems),

or a volatile organic compound air

emission (no-clean technologies). Each

alternative offered significant financial

advantages as compared to the traditional solvent degreasing systems when

the economics were evaluated using

activity-based cost accounting.

The national environmental impact

evaluation compared the life-cycle environmental impacts of traditional chlorinated solvent systems to the

alternatives. The evaluation suggests

that significant reductions in life-cycle

chemical emissions will occur with the

implementation of alternative cleaning

systems. Generally, for the aqueous

wash systems, the shift would mean

increased wastewater loads and oily

pollutant discharges to POTWs. The

nation’s POTW infrastructure, in aggregate, can handle these increased loads.

The shift in waste stream composition,

however, must be evaluated on a caseby-case basis.

This Project Summary was developed

by EPA’s National Risk Management

Research Laboratory, Cincinnati, OH to

announce key findings of the research

project that is fully documented in a

separate report of the same title (see

Project Report ordering information at

back).

Introduction

The “Cleaner Technology Demonstrations for the 33/50 Chemicals” project is a

cooperative agreement between the U.S.

EPA/600/SR-95/120 August 1995
2

Environmental Protection Agency (EPA),

National Risk Management Research

Laboratory (NRMRL, formerly Risk Reduction Engineering Laboratory) and the

Center for Clean Products and Clean Technologies (Center) of The University of Tennessee. The research of this project

supports the voluntary pollution prevention initiatives of the 33/50 Program, while

having applications within a broad range

of industries. This report represents the

first demonstration project to be completed

under the EPA NRMRL project.

Objectives

The overall objective of this project was

to evaluate substitutes for the 33/50 chemicals in order to encourage reductions in

their use and release. This report focuses

on substitutes for solvent degreasing processes that eliminate the use of the 33/50

chlorinated organic chemicals. In this study

the Center worked directly with an industry partner, Calsonic Manufacturing Corporation (CMC) of Shelbyville, TN, to

demonstrate substitute feasibility.

To meet the project objective, technical,

environmental, and economic evaluations

of solvent degreasing substitutes were

evaluated. A fourth evaluation, a national

environmental impact evaluation, was performed to estimate the impacts to the

nation’s environment if entire industrial

sectors were to implement similar alternatives to solvent degreasing. Within each

evaluation, the following objectives were

established:

1. Technical Evaluation

• evaluate the effect of a substitute

on process and product performance as compared to the 33/50

chemicals

2. Environmental Evaluation

• evaluate the potential for reduction

in releases and off-site transfers of

the 33/50 chemicals in the production process or product stage

• compare the overall life-cycle environmental attributes of the substitute as compared to the 33/50

chemicals

3. Economic Evaluation

• evaluate the total cost of the substitute as compared to the 33/50

chemicals

4. National Impact Evaluation

• evaluate the national environmental impact of replacing the 33/50

chemicals with the substitute

Methodology

Data required to perform the technical,

environmental, and economic evaluations

were collected through data request tables,

site visits, and interviews with CMC employees. Data request tables, completed

by CMC and during site visits, allowed for

the collection of process information including capital costs, operating and maintenance costs, utilities consumption, and

production data. Similar data were requested for both the solvent degreasing

systems (historic data) and alternative systems (current data). Questions concerning generation rates and disposal costs of

waste (hazardous and non-hazardous) and

waste water accompanied the data request tables, as well as questions concerning permitting requirements and costs.

These questions were also directed at operations both before and after the process

changes.

Site visits and interviews allowed Center staff to become familiar with the operations of CMC, ask specific questions to

complete and clarify the data request

tables, and to maintain a working contact

with CMC. An extended site visit near the

completion of this project was conducted

to observe the day-to-day operations of

the process lines under investigation in

order to extend the traditional economic

evaluation by using activity-based cost

accounting.

The national impact evaluation utilized

the knowledge of CMC’s process changes

to identify and evaluate potential changes

on a national scale if entire industrial sectors were to implement similar solvent

degreasing alternatives. to CMC’s. Toxic

Release Inventory (TRI) data and information from various literature sources were

used to develop a life-cycle evaluation of

chlorinated solvent degreasing and its alternatives.

CMC’S Chlorinated Solvent

Substitutes Program

CMC is located in Shelbyville, TN, with

several sister companies throughout the

U.S. and the world. CMC employs approximately 800 persons, and has more

than 430,00 ft2 of manufacturing area divided between two sites, three buildings.

CMC manufactures automotive parts, including heaters, blowers, cooling units,

motor fans, radiators, auxiliary oil coolers

and exhaust systems.

To meet internal protocols to eliminate

1,1,1-trichloroethane (TCA) from its manufacturing processes, CMC initiated a number of changes to eliminate solvent

degreasing applications. These changes

included an aqueous wash system, a noclean process which employs an evaporative lubricant to eliminate the need for

solvent degreasing, and the application of

a hot water wash to remove forming oils.

Technical, environmental, and economic

evaluations were performed for the aqueous wash and no-clean alternatives to determine their merits. The merits of the hot

water wash system were presented as

supplemental information to the aqueous

wash alternative. An introduction to these

process changes, and the manufacturing

lines which utilize them, is presented below.

The Radiator Line and Aqueous

Wash System

Radiators are designed to hold a large

volume of water and antifreeze in proximity to a large volume of air to allow efficient heat transfer from the fluid to the air.

CMC manufactures the tube-and-fin type

of radiator core, consisting of a series of

long tubes extending between a top tank

and bottom tank of the radiator. In this

type of configuration, fins are placed between the tubes; air passes between the

fins and around the outside of the tubes,

absorbing heat from the fluid in the tubes.

CMC manufactures the tubes and fins

of the radiator core from aluminum stock.

Tubes are formed from aluminum rolls at

a tube-forming station with the assistance

of a forming/cooling fluid, cut to length,

and sent to assembly. To form the fins,

rolls of aluminum are lubricated with a

forming (napthenic) oil, fed through fin

corrugators, cut to length, and sent to

assembly. The tubes, fins, and prefabricated endplates are assembled in a jig to

complete the radiator core.

Following assembly, the cores are

cleaned by a conveyor aqueous wash system to remove the forming oils, cutting

oils, coolant, and other soils. The aqueous wash process begins with a water

wash, intended to remove the majority of

the contaminants, followed by a heated

detergent bath, and completed by a hot

water rinse. Effluent from the aqueous

wash process is sent to a wastewater

treatment plant at the facility for pretreatment prior to discharge to the local sewer

system. After the aqueous wash, the radiator cores continue on the conveyor for

flux application, drying, and brazing. Final

assembly includes nylon fluid tanks and

leak testing.

The current aqueous wash system was

adapted in 1991. Previously, five batch

vapor degreasers were used to clean the

assembled radiator core, one located at

each fin corrugation and assembly station. Under this scheme the radiator core

was an assembly of corrugated fins (process above) and prefabricated tubes and

endplates supplied by another company.

These assemblies were then cleaned in

one of the five vapor degreasers, using

1,1,1-trichloroethane as the degreasing
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solvent. The use of TCA resulted in releases of TCA to the air from the process,

releases to water (wastewater) from solvent carry over on parts to subsequent

process units, and a hazardous waste

stream of spent TCA. CMC sent this hazardous waste stream to an off-site recycling facility. To eliminate these waste

streams and improve the cleaning process, CMC implemented the aqueous

wash system.

The Condenser Line and NoClean Technology

CMC manufactures condensers for use

in automobile air conditioning systems. The

condenser consists of a serpentine tube

on which fins have been mounted. Compressed vapor passes through the tube;

air passing around the fins and between

the tubes removes heat from the compressed vapor. The cooled vapor condenses and runs into a receiver-dryer.

CMC manufactures the fins from rolls of

aluminum, and bends and cuts the tubes

from rolled aluminum-tube stock.

In 1993 CMC converted its fin manufacturing process from a conveyor solvent

degreasing process using TCA to an

“evaporative” oil, no-clean process. In this

no-clean system, rolls of aluminum are

lubricated with a low-boiling-point oil and

fed through a fin corrugator. The fin then

passes through fin driers to evaporate the

oils. CMC operates four fin corrugator stations in the condenser line. In the current

system the corrugated fin is conveyed

through the now empty vapor degreasing

chambers, then cut to length and sent to

assembly.

The Converter Line and Hot

Water Wash System

Catalytic converters are automobile exhaust units which consist of a ceramic

substrate and wire mesh encased in a

metal shell. CMC assembles converters

from shells, flanges, ceramic substrates,

and wire mesh separators supplied by

other manufacturers. After receiving these

materials, CMC cleans the metal shell

halves and flanges in a conveyor hot water wash system to remove cutting and

lubricating oils left by the manufacturer.

The wash system consists of a hot water

spray zone, followed by a second hot water spray (rinse) zone and a drying oven.

After cleaning, the ceramic substrate and

wire mesh separator are inserted in the

two shell halves, which are then welded

together with the flanges, to form the converter unit. Each catalytic converter is leaktested using an air-based pressure-decay

system. The converters then continue

along the process train to be incorporated

into the exhaust system.

Until December 1993, CMC used a conveyor vapor degreaser with TCA as the

degreasing solvent. The current equipment

used in the hot water wash system was

converted by CMC from an obsolete muffler washing system and a defunct paint

spray booth and curing oven.

Results of the Technical,

Environmental, and Economic

Evaluations

Over the last four years CMC has implemented a number of changes to eliminate

TCA from its cleaning processes. Efforts

to accomplish this goal included the installation of an aqueous wash system (detergent) which replaced five solvent

degreasers on a radiator manufacturing

line, the replacement of a petroleum-based

lubricant with an evaporative lubricant that

does not require cleaning for subsequent

processing on a condenser manufacturing

line, and the installation of a hot water

wash system to replace a solvent

degreaser on a catalytic converter manufacturing line. These changes, along with

similar changes on other process lines,

eliminated the use of TCA as a cleaning

solvent within CMC’s manufacturing facility. Total elimination of TCA from cleaning

processes was accomplished by November, 1994.

The technical, environmental, and economic evaluations performed in this study

were completed using CMC’s historic

records, information obtained from site visits and interviews with CMC employees,

the on-line TRI data base, and literature

searches. The radiator and condenser

manufacturing lines were the main focus

of the research. The merits of the hot

water wash system were presented as

supplemental information to the aqueous

wash alternative. The environmental analysis of CMC was expanded to evaluate the

national environmental impacts if entire

industry sectors were to implement similar

process changes.

Technical Evaluation

The technical evaluation analyzed the

merits of the alternative cleaning systems

(both the aqueous wash and the no-clean,

evaporative lubricant systems) by comparing the rates of production (i.e., cycle

time required to clean one part) and the

part reject rates between the old and new

processes. Both historic data and interviews with CMC quality control staff established the results shown in Table 1.

A significant decrease in cycle time was

experienced with the implementation of

the aqueous wash system in the radiator

line; cycle time to clean one radiator unit

was decreased by 50%. The process

bottleneck, which was the solvent

degreasing application, has now shifted

away from the cleaning operation, and

employee attentions can be focused upon

other operations to further optimize the

manufacturing process.

A significant decrease in the parts reject rate for the radiator line was also

experienced after the implementation of

the aqueous wash system. This decrease,

over 76%, is predominantly attributed to

the improved cleaning characteristics of

the aqueous wash system. The production and part reject rates for the condenser

line, though not statistically evaluated due

to data limitations, were evaluated through

employee interviews. These interviews

established that the implementation of the

no-clean process alternative had little effect on either rate.

Environmental Evaluation

The changes in chemical releases and

transfers to the environment from CMC’s

manufacturing facilities due to the implementation of the alternative processes included the following:

1. elimination of TRI reporting requirements of TCA hazardous waste

emissions, from each process line;

2. the creation of a state-regulated

VOC air emission for the condenser

line; and

3. the creation of a waste water stream

for the radiator line.

These changes are summarized for the

radiator and condenser manufacturing lines

in the following table (Table 2). It is assumed that air releases and hazardous

waste transfers are the only TCA emissions from CMC processes. Therefore,

Table 1. Summary of the Technical Evaluation Results

Line Cycle Time Part Reject Rate

Radiator 50% decrease was experi- 76% reduction in part reject rate due

enced after aqueous wash to aqueous wash system

implementation

Condenser no significant change no significant change
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Table 2. Summary of Environmental Evaluation Results

Total Waste Generation per Year

Line

Solvent Degreasing Operations Alternative Systems Operations

Radiator 171,500 lb TCA consumed 22,100 lb detergent consumed

114,900 lb TCA haz. waste transfers 2.0 million gal wastewater generated

 56,600 lb TCA air releases 10,800 lb non-haz., oily waste transfers

 (1990) 64,780 lb non-haz. wastewater treatment solids transfers

(1992)

Condenser 121,500 lb TCA consumed 12,200 lb evap. lub. consumed

 14,400 lb petroleum lub. consumed 12,200 lb VOC air releases

 75,400 lb TCA haz. waste transfers (1994)

 46,100 lb TCA air releases

(1992)

based on TCA consumption rates and linespecific hazardous waste generation estimates, the air releases were estimated.

Other line-specific information was drawn

directly from purchasing records.

Though eliminating the use and hazardous waste disposal of TCA, the hot water

wash system of the converter line was not

quantitatively evaluated in this analysis.

However, a qualitative evaluation of this

system is presented throughout the evaluations of the report.

Though the aqueous wash system of

the radiator line generates two million gallons of wastewater per year, overall chemical consumption, when compared to the

solvent degreasing system, has greatly

decreased. The consumption rate of 2,640

gal/yr of detergent is minimal when compared to the 15,840 gal/yr (171,700 lb/yr)

of TCA previously consumed. The evaporative lubricant system of the condenser

line has similar advantages; the release

of 12,200 lb/yr of VOC-lubricant is an order of magnitude less than the 121,500

lb/yr of TCA released by the degreasers.

These data clearly show the trade-off

issues that must be considered when

choosing between alternative cleaning systems. For the radiator line, releases of the

toxic, ozone-depleting chemical TCA were

eliminated, but a larger volume, low-toxicity wastewater stream was generated. Although hazardous waste management

requirements have been eliminated for this

line, permitted discharge requirements set

by the local publicly owned treatment

works (POTW) must still be met. For the

condenser line, hazardous waste and TCA

were once again eliminated. Air releases

decreased substantially, suggesting less

potential employee exposure; complete

data on the relative toxicity of TCA and

the mineral-spirit-based VOCs emitted by

the evaporative lube, however, are not

available. This is one of the reasons CMC

is now switching to a non-petroleum based

evaporative lube.

Economic Evaluation

Two economic evaluations were completed for the analyses of the alternatives.

The first evaluation used a traditional

method focusing on direct costs. The second method utilized activity-based costing

to more accurately allocate overhead costs

to the appropriate products and processes.

Finally, a hybrid of these methods was

used to more accurately represent the

costs and benefits of the alternatives.

Tables 3 and 4 summarize the results of

traditional and hybrid economic analyses

for the radiator and condenser manufacturing lines, respectively.

Table 3 shows that the hybrid method

identified additional direct costs associated with the solvent degreasing units of

the radiator line that would have been

part of an overhead cost factor in a more

traditional analysis. These results illustrate

very clearly that traditional cost analyses

are not adequate to fully estimate the benefits of pollution prevention projects. By

properly allocating through ABC that would

normally be part of an overhead factor,

this study demonstrates the costs-benefits

of the aqueous wash system, benefits beyond traditional costing techniques are realized.

The results of the economic analysis for

the condenser line did not change the

final conclusions since the evaporative lube

system had clear advantages even with

traditional cost methods. By using the hybrid approach, however, the cost savings

due to the implementation of this alternative were even greater.

National Environmental Impact

Evaluation

The environmental evaluation of CMC’s

process changes was used to estimate

the potential environmental impacts of the

alternatives to solvent degreasing if entire

industrial sectors were to implement similar changes. This evaluation utilized the

life-cycle concept to evaluate the potential

environmental impacts which could result

throughout the life cycle of the chemicals

used in the traditional and alternative processes. The elimination of chlorinated solvents from materials and parts degreasing

could significantly impact the national emissions of these chemicals from their production, use and disposal. The implementation

of the alternative systems, though having

associated releases and transfers of other

chemicals, could significantly decrease the

environmental impacts now associated with

the life cycle of solvent degreasers and

the solvents used.

Replacing chlorinated solvent degreasers could substantially reduce the use of

approximately 499.9 million lb of chlorinated chemicals in materials and parts

degreasing applications. In addition to the

direct use and disposal emissions that

would be reduced, an estimated 460,000

lb of solvent emissions from production

facilities could also be reduced. This

460,000 lb estimate is based on the quantity of the chlorinated solvents currently

produced, the emissions from these production processes, and the distribution of

the chemicals to solvent degreasing applications.
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Table 3. Comparison of Hybrid and Traditonal Analyses-Radiator Manufacturing Line

Hybrid Analysis Tradition, Direct Cost Analysis

Analysis Solvent System Aqueous Wash System Solvent System Aqueous Wash System

Payback 2.4 yr 11.6 yr

NPV (5-yr) $2,584,150 $1,514,260 $660,580 $808,280

NPV (10-yr) $5,725,530 $3,073,640 $1,464,270 $1,508,720

NPV (15-yr) $9,547,510 $4,762,870 $2,442,090 $2,147,930

Notes: 1. i = interest rate/period = 4%.

2. the capital investment of the aqueous wash system was depreciated (straight-line) over seven yr.

3. assumptions: inflation rate of zero and equal costs/yr.

4. dollar values represent costs.

Table 4. Comparison of Hybrid and Traditional Analyses-Condenser Manufacturing Line

Hybrid Analysis Tradition, Direct Cost Analysis

Analysis Solvent System Evaporative Oil System Solvent System Evaporative Oil System

Payback 0.27 yr 0.45 yr

NPV (5-yr) $1,089,550 $219,660 $619,750 $99,930

Notes: 1. i = interest rate/period = 4%.

2. the capital investment of the aqueous wash system was depreciated (straight-line) over 7 yr.

3. assumptions: inflation rate of zero and equal costs/yr.

4. dollar values represent costs.

The implementation of an aqueous wash

alternative has unique emissions of its

own. Detergents, a mixture of surfactants,

builders, chelators, and other ingredients,

have associated chemical production releases and transfers. Emissions from production of commonly used ingredients

(e.g., ethoxylated alcohols, alkylbenzene

sulfonates, EDTA, and tetrapotassium pyrophosphate) include ethylene, ethylene

glycol, benzene, glycol ether, and a variety of acids. An estimate of the quantity of

detergent ingredients applied to industrial

applications was not available, and therefore an estimate of the production releases

which could be allocated to the industrial

use of detergents was not possible. However, order-of-magnitude calculations show

that life-cycle releases and transfers could

be significantly reduced with the implementation of the aqueous alternative.

A second issue to address when considering the life-cycle attributes of aqueous wash systems is the proper

management of the water waste stream.

Pretreatment of the wastewater from aqueous systems may be required to adequately remove oils, greases, biological

oxygen demand (BOD), and suspended

solids. The conclusions from the national

environmental impact evaluation indicated

that the infrastructure of wastewater treatment facilities is sufficient to handle the

increased wastewater flow and load if entire industry sectors shifted from solvent

to aqueous systems.

Conclusions

The demonstration strongly supports the

implementation of the alternative technologies. The implementation of the cleaning

process alternatives either improved or

did not affect the performance of subsequent process steps or the quality of the

products. The aqueous wash system reduced cleaning cycle times by 50% and

part reject rates by nearly 77% with improved cleaning characteristics. The noclean alternative had no effect on either

production or part reject rates. The substitutes significantly reduced the quantity of

toxic chemicals used and released. The

traditional processes released 1,1,1-

trichloroethane (TCA) to the air, as well

as generating a TCA hazardous waste

stream; the substitutes generate either a

non-hazardous wastewater discharge

(aqueous and hot water wash systems),

or a volatile organic compound air emission that is much less no-clean technology. Each alternative offered significant

financial advantages as compared to the

traditional solvent degreasing systems

when using activity-based cost accounting and compared to the traditional solvent degreasing systems.

The national environmental impact

evaluation compared the life-cycle environmental impacts of traditional chlorinated

solvent systems versus the alternatives.

The evaluation suggests that significant

reductions in life-cycle chemical emissions

will occur with implementation of alternative cleaning systems. Generally, for the

aqueous wash systems, the shift would

mean increased wastewater loads and oily

pollutant discharges to POTWs. The

nation’s POTW infrastructure, in aggregate, can handle these increased loads,

however, the shift in waste stream composition must be evaluated on a case-bycase basis.
6

Dean M. Menke, Gary A. Davis, Lori E. Kincaid, and Rupy Sawhney are with

the University of Tennessee, Knoxville, TN 37996-0710

Diana R. Kirk is the EPA Project Officer (see below).

The complete report, entitled "Demonstration of Alternative Cleaning Systems,"

(Order No. PB95-255741; Cost: $27.00, subject to change) will be

available only from:

National Technical Information Service

5285 Port Royal Road

Springfield, VA 22161

Telephone: 703-487-4650

The EPA Project Officer can be contacted at:

National Risk Management Research Laboratory

U.S. Environmental Protection Agency

Cincinnati, OH 45268

BULK RATE

POSTAGE & FEES PAID

EPA

PERMIT No. G-35

United States

Environmental Protection Agency

Technology Transfer and Support Division (CERI)

Cincinnati, OH 45268

Official Business

Penalty for Private Use

$300

EPA/600/SR-95/120