&EPA
United States
Environmental Protection
Agency
Research and Development
Risk Reduction
Engineering Laboratory
Cincinnati, OH 45268
EPA/600/S-92/055 October 1992
ENVIRONMENTAL
RESEARCH BRIEF
Waste Reduction Activities and Options for a Manufacturer of
Fine Chemicals Using Batch Processes
Patrick Eyraud and Daniel J. Watts*
Abstract
The U.S. Environmental Protection Agency (EPA) funded a project
with the New Jersey Department of Environmental Protection and
Energy (NJDEPE) to assist in conducting waste minimization as-
sessments at 30 small- to medium-sized businesses in the Sjtate of
New Jersey. One of the sites selected was a manufacturer of fine
chemicals using batch processes. A site visit was made in 1990
during which several opportunities for waste minimization were
identified. Options identified for waste reduction included initiation of
solvent recycling or reconditioning for reuse and modifying the
chemical reaction conditions to improve product quality and reduce
the amount of reprocessing which has been necessary. Implemen-
tation of the identified waste minimization opportunities was not part
of the program. Percent waste reduction, net annual savings, imple-
mentation costs and payback periods were estimated.
This Research Brief was developed by the Principal Investigators
and EPA's Risk Reduction Engineering Laboratory in Cincinnati,
OH, to announce key findings of this completed assessment.
Introduction
The environmental issues facing industry today have expanded
considerably beyond traditional concerns. Wastewater, air emis-
sions, potential soil and groundwater contamination, solid waste
disposal, and employee health and safety have become increasingly
important concerns. The management and disposal of hazardous
substances, including both process-related wastes and residues
from waste treatment, receive significant attention because of regu-
lation and economics.
As environmental issues have become more complex, the strategies
for waste management and control have become more systematic
* New Jersey Institute of Technology, Newark, NJ 07102
and integrated. The positive role of waste minimization and pollution
prevention within industrial operations at each stage of product life is
recognized throughout the world. An ideal goal is to manufacture
products while generating the least amount of waste possible.
The Hazardous Waste Advisement Program (HWAP) of the Divi-
sion of Hazardous Waste Management, NJDEPE, is pursuing the
goals of waste minimization awareness and program implementation
in the state. HWAP, with the help of an EPA grant from the Risk
Reduction Engineering Laboratory, conducted an Assessment of
Reduction and Recycling Opportunities for Hazardous Waste (AR-
ROW) project. ARROW was designed to assess waste minimization
potential across a broad range of New Jersey industries. The
project targeted 30 sites to perform waste minimization assessments
following the approach outlined in EPA's Waste Minimization Op-
portunity Assessment Manual (EPA/625/7-88/003). Under contract
to NJDEPE, the Hazardous Substance Management Research
Center at the New Jersey Institute of Technology (NJIT) assisted in
conducting the assessments. This research brief presents an as-
sessment of the manufacturing of fine chemicals using batch pro-
cesses (1 of the 30 assessments performed) and provides recom-
mendations for waste minimization options resulting from the as-
sessment.
Methodology of Assessments
The assessment process was coordinated by a team of technical
staff from NJIT with experience in process operations, basic chem-
istry, and environmental concerns and needs. Because the EPA
waste minimization manual is designed to be primarily applied by
the inhouse staff of the facility, the degree of involvement of the
NJIT team varied according to the ease with which the facility staff
could apply the manual. In some cases, NJITs role was to provide
advice. In others, NJIT conducted essentially the entire evaluation.
Printed on Recycled Paper
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The goaJ of the project was to encourage participation in the
assessment process, by management and staff at the facility. To do
this, the participants were encouraged to proceed through the
organizational steps outlined in the manual. These steps can be
summarized as folbws:
Obtaining corporate commitment to a waste minimization
initiative
Organizing a task force or similar group to carry out the
assessment
Developing a policy statement regarding waste minimiza-
tion for issuance by corporate management
Establishing tentative waste reduction goals to be achieved
by the program
Identifying waste-generating sites and processes
Conducting a detailed site inspection
Developing a list of options which may lead to the waste
reduction goal
Formally analyzing the feasibility of the various options
Measuring the effectiveness of the options and continuing
the assessment.
Not every facility was able to follow'these steps as presented. In
each case, however, the identification of waste-generating sites and
processes, detailed site inspections, and development of options
was carried out. Frequently, it was necessary for a high degree of
involvement by NJIT to accomplish these steps. Two common
reasons for needing outside participation were a shortage of techni-
cal staff within the company and a need to develop an agenda for
technical action before corporate commitment and policy statements
could be obtained.
It was not a goal of the ARROW project to participate in the
feasibility analysis or implementation steps. However, NJIT offered
to provide advice for feasibility analysis if requested.
In each case, the NJIT team made several site visits to the facility.
Initially, visits were made to explain the EPA manual and to encourage
the facility through the organizational stages. If delays and compli-
cations developed, the team offered assistance in the technical
review, inspections, and option development.
No sampling or laboratory analysis was undertaken as part of these
assessments.
Facility Background
The facility is an integrated chemical production installation which is
part of the manufacturing capability of a large chemical production
company. The facility which participated in this study houses pilot
plant activities for fine chemicals and for chemical intermediates
under investigation by the company. In addition, some manufactur-
ing of products, particularly bw volume products occurs at this
facility. The facility also hosts research activities, packaging operatbns,
and Quality Assurance laboratory activities. The site is approximately
50 years old, although most of the buildings are significantly newer.
The equipment in use varies from brand new to over 30 years in
age.
Manufacturing Processes
Although many independent operatbns take place at this installa-
tbn, it was decided to focus this initial effort on one of the smaller
manufacturing operatbns. Such a focus was expected to provide
the technical and operating management of the facility an illustratbn
of the assessment process and provide the informatbn necessary to
plan a larger scale assessment process for the entire facility. It was
desirable, therefore, to select a discrete process which could be
thoroughly analyzed and whbh held potential for measurable and
significant pollutbn preventbn opportunities.
The process investigated uses relatively uncomplicated chemistry
requiring formatbn of a coordinatbn-type complex between an
organb amine and a volatile habgen-containing solvent. The com-
plexatbn is carried out in the presence of a small amount of an
alcohol co-solvent. The individual components are synthesized either
offsite or in an area separate from the complexation equipment and
process. The process involved is a relatively simple three component
mixing and complexatbn reaction whbh albws for an in-depth
analysis of waste streams and consideration of alternatives.
Typical steps in the manufacturing process include the folbwing
activities:
A concentrated solution of the organic amine in an alcohol
solvent is slowly added to a large volume of vigorously
agitated halogen-containing solvent.
As a result of the mixing, a portion of the resulting amine/
solvent complex precipitates.
The product yield is increased by distilling off a portion of
the halogen-containing solvent in order to induce crystalli-
zation of the product complex.
The product is recovered by filtration by vacuum.
Recovered solvent is sent offsite for recycling.
Existing Waste Management Activities
The company has already recognized the advantages and benefits
of identifying and implementing waste reductbn and pollution pre-
vention practices. The current procedure which utilizes offsite recycling
for the waste streams from the investigated process illustrates that
recognition and commitment.
Waste Minimization Opportunities
For this facility, the initial use of the manual was carried out by the
staff of the facility. The NJIT team partbipated in identifbation of
some of the optbns for waste reduction. During the assessment
process, the folbwing waste streams were identified:
Liquid Solvent Stream
Vapor Losses
The liquid solvent waste stream results from distillatbn of solvent to
raise the product concentratbn to induce crystallization and from the
recovery of the product by filtratbn. It has been generated at a rate
of about 19,000 kg/yr. The waste stream has been managed by
offsite recycling at an annual cost of about $12,000.
The vapor loss stream results from atmospherb bsses during the
solvent transfer to a receiving vessel. A minor portion of the bss has
been estimated to result from leaking connections and escape
during vessel openings. More of the vapor bss results from the
vacuum filtratbn step which is used to recover the solid product. A
portion of the volatile solvent is lost through the vacuum system and
is not easily recovered. It is estimated that about 1200 kg of the
mixed solvents are bst annually through these routes. The fraction
which is captured is sent offsite for recycling at an annual cost of
about $500.
The continuing technical challenge is to reduce further the size of the
two waste streams resulting from the process. Technically, it may be
easier to reduce the amount of vapor bss by tighter vapor handling
practices. Because the volume of the liquid solvent stream is greater,
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there may be greater opportunities there for high percentage reduc-
tion.
to avoid scheduling production runs during times of the year when
ambient humidity would be expected to be high.
From the perspective of pollution preventbn, the company may
desire to look for options which reduce emissbns to the atmo-
sphere, reduce the total amount of chemical usage, encourage
onsite recycling or reuse of the materials, or albw use of less
hazardous substances in the manufacture and processing of the
product. However, it was decided that the performance requirements
for the product precluded any changes in the chemistry of the
process until a detailed product characterization and performance
evaluatbn could be carried out. Therefore, any changes in the
actual substances used to manufacture the product could not be
considered to be a viable initial pollutbn preventbn optbn. Rather,
both of the two waste streams were considered individually to
identify the reasons for the size of the streams and possible modifi-
catbn of practices whbh had potential for their reductbn.
The liquid solvent stream presented the greatest challenge in terms
of volume. The relatively high cost of the solvents/reactants in the
process had prevbusly led to consideratbn of alternative ratios of
materials in order to minimize solvent use. The existing process
used the minimum volumes required in order to achieve the neces-
sary performance for the product.
The solvent waste stream is sent offsite for recycling because the
combinatbn of alcohol co-solvent with the halogen-containing solvent
presents some complicatbns with the distillatbn process whbh
would normally be used for solvent purifbatbn. The necessary
equipment to carry out this purifbatbn does not exist at the site and
the relatively small volume of this stream does not justify investment
in such equipment at this time. The required distillation equipment
does exist at another company-owned site, however, so one of the
optbns identified is to move this process to another company
bcatbn in order to permit onsite recovery, recycling and reuse of the
solvent.
An alternative to this optbn was also identified which would utilize a
two-step purifbatbn of the solvent system. The concept proposed
was to utilize an adsorbent for the alcohol component which, in a
packed bed medium, could selectively remove the alcohol leaving
the halogen-containing solvent in a more easily purified state allow-
ing distillatbn with existing equipment at the site. Alternatively, it may
be possible to reuse the halogen-containing solvent directly although
this would have to be verified by product quality and performance
testing. An appropriate chobe of alcohol adsorbent could albw
regeneratbn with recovery and reuse of the alcohol. Such a proce-
dure would be expected to reduce substantially the percentage of
this waste stream whbh needs to be sent for treatment.
Another alternative optbn addressed the issue of reductbn of the
volume of raw materials used in the process itself. Although, as
indbated prevbusly, it would not be possible to implement a new
process using smaller quantities of the materials, examination of the
productbn records indbated that about 10% of the batch runs
represented reworking of batches whbh failed quality standards.
Stated another way, this means that a savings of 10% of the waste
stream could be realized by identifying and correcting the reasons
for the bebw standard quality of these batches. It was determined
that the product complex whbh is formed is sensitive to the presence
of water. In fact, moisture can cause the decomposition of the
complex. The presence of high humidity during the complexatbn
process was determined to be the primary cause of the 10% failure
rate. It was proposed, therefore, to provide a more controlled tem-
perature/humidity environment for the manufacturing process to
eliminate the failures of these batches. An alternative suggestion was
The vapor bss waste stream presented some addrtbnal challenges.
As indbated prevbusly, two significant sources for such losses were
identifiedfugitive emissbns and the filtratbn step in the product
recovery phase of the process. These two sources lead to sugges-
tbns of different types of optbns for reductbn of vapor bss.
Several applbatbns of modified engineering practbes were identified
for reductbn of fugitive bsses. These included improved control
over condenser temperature and reactbn temperature, use of cou-
plings and connectors with bw dead volume, regular inspectbn and
replacement when necessary of seals, valves, and pressure relief
devices. Modified practbes such as gravity-induced introductbn of
solvents rather than by pumping to reduce any pressure buildup in
the reactbn vessel were also suggested.
While it may be difficult to quantify the pollutbn preventbn impact of
optbns such as these, it is clear that they have the potential for
reducing fugitive emission.
Addressing the issue of vapor bsses during the filtratbn process
required identifbatbn of different optbns. It was determined that the
bsses occurred because the relatively bw-boiling solvent vaporized
under the vacuum filtratbn conditbns and was bst through the
vacuum system. The optbn identified to reduce such bsses was to
utilize existing equipment to carry out pressure filtratbns instead of
vacuum filtratbn. The same pressure drop across the fitter could be
achieved, but because the absolute pressure in the system was
higher, volatilization could be reduced substantially. Therefore, solvent
bss would be reduced.
The type of waste currently generated by the facility, the source of
the waste, the quantity of the waste and the annual treatment and
disposal costs are given in Table 1.
Table 2 shows the opportunities for waste minimizatbn recom-
mended for the facility. The type of waste, the minimizatbn opportunity,
the possible waste reductbn and associated savings, and the
implementation cost abng with the payback time are given in the
table. The quantities of waste currently generated at the facility and
possible waste reductbn depend on the level of activity of the facility.
It should be noted that the economb savings of the minimizatbn
opportunity, in most cases, results from the need for less raw
material and from reduced present and future costs associated with
waste treatment and disposal. It should also be noted that the
savings given for each opportunity reflect the savings achievable
when implementing each waste minimizatbn opportunity indepen-
dently and do not reflect savings that would result when the oppor-
tunities are implemented in a package.
Regulatory Implications
An important regulatory implication in this study is that although the
majority of the waste stream from this process is recycled, it is sent
offsite for purifbatbn and reuse. Therefore, the streams are classi-
fied as waste. Even though the company has at a nearby site the
technbal capability to purify the material and return it to the original
process, regulatory barriers prevent the ready implementation of this
practice. The regulatory issue is that because the two facilities are
considered separately from a regulatory point of view, the material
would have to be sent from this facility under a hazardous waste
manifest. Then even after purifbatbn it would still be considered
hazardous waste unless the company went through a process to
have it delisted. Even then, the company would be seen as using a
&U.S. GOVERNMENT PRINTING OFFICI'.: 1994 - 550-067/80180
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"hazardous waste" in the manufacture of its products. The company
is not willing to argue against this type of public perception.
This Research Brief summarizes a part of the work done under
cooperative Agreement No. CR-815165 by the New Jersey Institute
of Technology under the sponsorship of the New Jersey Depart-
* Mention of trade names or commercial products does not constitute endorsement
or recommendation for use.
ment of Environmental Protection and Energy and the U.S. Environ-
mental Protection Agency. The EPA Project Officer was Mary Ann
Curran. She can be reached at:
Pollution Prevention Research Branch
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
Table 1. Summary of Current Waste Generation
Waste Generated
Liquid Solvent Stream
Filtrate
Vapor Loss
Source of Waste
Solvent distillation
Filtration of solid product
Fugitive emissions
Annual Quantity
Generated
19,000 kg
1,200kg
variable at least 1000 kg
Annual Waste
Management Costs
$12,000
500
500
Tab!* 2. Summary of Recommended Waste Minimization Opportunities
Waste Stream
Reduced
Liquid Solvent
Stream
Vapor Loss
Vapor Loss
Fugitive Emissions
Minimization Opportunity
Purify onsite for recycling by
straight distillation
Move process to other facility
where distillation equipment
already exists
Reduce frequency of product
rework by controlling ambient
humidity
Change from vacuum filtration
to pressure
Introduce various techniques
such as improved condenser and
reaction temperature control,
regular inspection for leaks,
and introduction of solvents
by gravity instead of pressure
Annual Waste Reduction
Net
Quantity
18,000 kg
18,000 kg
Percent
94
94
Annual Savings
$16,500
16,500
Cost
$120,000
200,000
Years '
7.3
12.1
1900kg
1,000kg
800kg
10
84
80
1,750
500
400
2,000
0
existing
500
1.1
1.2
' Savings result from reduced raw material and treatment and disposal costs when implementing each minimization opportunity independently.
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
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EPA
PERMIT No. G-35
EPA/600/S-92/055
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