vvEPA
United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/625/R-99/005
July 1999
Volatile Organic
Compounds (VOC)
Recovery Seminar
September 16-17, 1998
Cincinnati, OH
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EPA/625/R-99/005
July 1999
Volatile Organic Compounds (VOC)
Recovery Seminar
September 16-1 7, 1998
Cincinnati, OH
Sustainable Technology Division
Technology Transfer and Support Division
Air Pollution Prevention and Control Division
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
Printed on Recycled Paper
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Notice
This document has been reviewed in accordance with US. Environmental Protection Agency
policy and approved for publication. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
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Contents
Notice ii
Contents iii
List of Tables v
List of Acronyms vi
Introduction viii
Risk Management: Strategic Issues for Volatile Organic Compounds (VOCs)
in the Environment by Subhas Sikdar 1
VOCs: Sources, Definitions, and Considerations for Recovery by Carlos Nunez 3
Overview of VOC Recovery Technologies by Kamaiesh Sirkar 5
Industrial Research Programs by Edward Moretti 10
VOC Recovery Research at EPA Office of Research and
Development (ORD) by Teresa Harten , . . , , 12
Short Flow Path Pressure Swing Adsorption - Lower Cost Adsorption Processing
SHERPA by William Asher , , 14
Solvent Recovery Applications at 3M by James Carmaker 16
The Economics of Recovery: Using the Office of Air Quality, Planning,
and Standards (OAQPS) Cost Manual as a Tool for Choosing the Right
Reduction Strategy by Daniel Mussatti ,....,. 18
Rotary Concentration and Carbon Fiber Adsorption by Ajay Gupta 21
Zeolite Absorption and Refrigeration - CONDENSORB VOC Recovery
System by Jon Kostyzak 23
A Novel Fluidized Bed Concentrator System for Solvent Recovery of High Volume,
Low Concentration VOC-laden Emissions by Edward Biedell 25
Recovery of VOCs by Microwave Regeneration of Adsorbents by Philip Schmidt 27
Removal and Recovery of Volatile Organic Compounds for
Gas Streams by Hans Wijmans 30
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Contents (Cont'd)
Synthetic Adsorbents in Liquid Phase and Vapor Phase
Applications by Steven Billingsley . . . . , 32
Cryogenic Condensation for VOC Control and Recovery by Robert Zeiss 34
Brayton Cycle Systems for Solvent Recovery by Joseph Enneking 35
Control of VOCs in Refinery Wastewater by Mike Worrall 37
Separation of Volatile Organic Compounds from Water by
Pervaporation by Richard Baker 39
Dehydration and VOC Separation by Pervaporation for Remediation
Fluid Recycling by Leland Vane 41
Polymeric Resins for VOC Removal from Aqueous Systems by Yoram Cohen 43
The New Clean Process Advisory System (CPAS) Separation Technology
and Pollution Prevention Information Tool by Robert Patty 47
Comparative Cost Studies by Edward Moretti 51
Availability of Technology Information, Including Internet-Based
Sources by Heriberto Cabezas 53
Paint Spray Booth Design Using Recirculation/Partitioning
Ventilation by Charles Darvin .., , . . , 56
Summary and Concluding Remarks/Seminar Follow-Qn Efforts by Scott Hedges 59
Breakout Session Summaries 60
Appendix A - List of Seminar Attendees , 63
Appendix B - Breakout Group Notes and Members 70
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List of Tables
1. Process Options for Removing VOCs from Vent Streams 7
2. Typical VOC/Water Separation Factors in Pervaporation 9
3. Polymer Resins Versus Activated Carbon 45
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List of Acronyms
ACA Air Compliance Advisor
AERP" Air Emission Reduction Program
AlChE American Institute of Chemical
Engineers
BACT Best Available Control Technology
BCA beaded carbonaceous adsorbent
BRU Benzene Removal Unit
BTUs British Thermal Units
BTEX benzene, toluene, ethylene, and
xylene
BTX benzene, toluene, and xylene
CenCITT Center for Clean Industrial and
Treatment Technologies
CERI Center for Environmental
Research Information
cfm cubic feet per minute
CPI The Construction Productivity
Institute
CRADA Cooperative Research and
Development Agreement
CWRT Center for Waste Reduction
Technologies
DNAPL dense non-aqueous phase liquid
DOD Department of Defense
DOE Department of Energy
ฐC degrees Celsius
EPA Environmental Protection Agency
ฐF
gpm
HAPs
I PA
kcal/mole
kOH
kW
Ibs/hr
LEL
LNAPL
m2/g
m3/hr -
MACT
degrees Fahrenheit
gallons per minute
hazardous air pollutants
isopropyl alcohol
kilocalories per mole
reaction rate constant for the
reaction of a compound with an
hydroxyl radical
kilowatt
pounds per hour
lower explosive limits
light non-aqueous phase liquid
square meters per gram
cubic meters per hour
Maximum Achievable Control
Technology
mg HC/liter milligrams hydrocarbon per liter
mg HC/Nm3
mg/L
mg/m3
MIR
mm Hg
MS
NAPLs
milligrams of hydrocarbon per
normal cubic meter
milligrams per liter
milligrams per cubic meter
maximum incremental reactivity
millimeter of mercury
Molecular Sieve
non-aqueous phase liquids
VI
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List of Acronyms (continued)
NESHAPs National Emission Standards for
Hazardous Air Pollutants
NJIT New Jersey Institute of
Technology
NOX nitrogen oxides
nPA n-propyl alcohol
NRMRL National Risk Management
Research Laboratory
O&M operation and maintenance
OAQPS Office of Air Quality, Planning,
and Standards
OH hydroxyl
ORD Office of Research and
Development
P2P Pollution Prevention Progress
PM particulate matter
ppb parts per billion
ppm parts per million
ppmv parts per million by volume
ppmw parts per million by weight
PPPS&D Pervaporation Performance
Prediction Software and Database
PSA pressure swing adsorption
psia pounds per square inch area
PVC poly vinyl chloride
R&D research and development
RIA Regulatory Impact Analysis
SAB Science Advisory Board
scfm standard cubic feet per minute
SEE Senior Environmental Employee
SERDP Strategic Environmental Research
and Development Program
SIP State Implementation Plan
SITE Super-fund Innovative Technology
Evaluation
SOX sulfur oxides
TRI Toxic Release Inventory
TTN Technology Transfer Network
TWA time weighted average
UCLA University of California, Los
Angeles
UT University of Texas
uv ultraviolet
VCM vinyl chloride monomer
voc Volatile Organic Compound
% percent
Vll
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Introduction
The Volatile Organic Compounds (VOC) Recovery Seminar was held September 16 - 17, 1998,
in Cincinnati, Ohio. The seminar was cosponsored by the U.S. Environmental Protection Agency's
(EPA's) National Risk Management Research Laboratory (NRMRL), the U.S. Department of
Energy (DOE), the American Institute of Chemical Engineers (AlChE), and the AlChE-affiliated
Center for Waste Reduction Technologies (CWRT). Representatives from industry, academia,
consulting firms, and government attended.
The purpose of the seminar was to bring researchers, technology developers, and industry
representatives together to discuss recovery technologies and techniques for VOCs. The seminar
focused on the specific VOC recovery needs of industry and on case studies that summarize
effective VOC product recovery techniques applicable to air, water, and solid waste. The case
studies highlighted examples in which existing and new recovery technologies resulted in
significant cost savings to industry.
The seminar focused on the following key issues:
Status and future direction of EPA, DOE, and other major research programs.
What are the latest technology innovations in VOC treatment and recovery?
Performance and cost effectiveness of VOC recovery techniques.
How are recovery techniques applied to air, water, and solid wastes?
Presenters were from industry, academia, EPA, and various consulting firms. The presentations
were followed by several facilitated breakout sessions; these sessions allowed participants an
opportunity to discuss their needs and opinions on VOC recovery trends, research, and other
issues.
This document contains summaries of the presentations and discussions during the seminar. It
does not constitute an actual proceedings, since the presentations were informal and no written
versions were required. The list of participants and contact information are included in Appendix
A.
Vlll
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Risk Management: Strategic Issues for Volatile Organic
Compounds (VOCs) in the Environment
Presented on September IS, 1998 by Subhas Sikdar, U.S. Environmental
Protection Agency (EPA) National Risk Management Research Laboratory
(NRMRL)
VOC recovery technologies are of particular interest to U.S. EPA NRMRL. The Cincinnati
laboratory needs to be familiar with both current and upcoming VOC recovery technologies in
order to support its technical role in EPA and to serve as a technical advisor to the regulatory
offices on these technologies.
The strategic issues associated with managing VOCs in the environment are: 1) what emissions
data tell us; 2) industrial emission sources; 3) where the problems are most evident; and 4)
strategies for reducing risks.
"What Emissions Data Tell Us" -Toxic VOCs in the Environment
VOC data indicate that the majority of VOC emissions are anthropogenic and dilute (i.e., man-
made and at low concentrations). While this information indicates that the majority of VOC
emissions can potentially be controlled (i.e., the man-made portion), the prevalence of low
concentration streams indicates that control may be difficult to accomplish since few technologies
are currently available to control/recover low concentration streams effectively. Since VOC
contamination in the air and water is a major health and ecological risk that can lead to
tropospheric ozone formation, stratospheric ozone depletion, lung disease, and cancer, promising
technologies capable of treating low concentration streams need to be developed.
Before Toxic Release Inventory (TRI) data were available, EPA and industry did not fully
comprehend industry's contribution to VOC releases. After TRI data were released, EPA was able
to comprehensively assess where pollution was originating and develop a strategy for its
reduction. TRI data resulted in the development of a number of programs to reduce emissions,
including the 33/50 Program for 17 chemicals, Project XL, and the Common Sense Initiative. TRI
data also helped make industry and citizens aware of the seriousness of the pollution issue. This
new awareness resulted in company-specific emission reduction programs, Responsible Care@
programs in the chemical industry, and the wide-scale acceptance of pollution prevention
programs.
"Industrial Emission Sources" and "Where the Problems Are Most Evident"
Based on 1998 emission projections, the chemical, primary metals, petroleum, paper, and food
industries generated the most production-related waste, with the chemical industry serving as the
largest emitter. A comparison with 1996 data indicates that the paper and primary metals
industries experienced emission reductions of 0.5 and 2.0 percent (%), respectively, and that
petroleum industry releases remained unchanged during this period. The chemical and food
industries, however, showed emission increases of 6.8% and 83.1%, respectively, from 1996 to
1998. It should be noted that many of the controls implemented by the chemical industry from
1996 to 1998 were overshadowed by the tremendous growth experienced by the industry during
that period.
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A review of production-related waste data indicates that, on a pound-per-pound basis, methanol
(245 million pounds), toluene (126 million pounds), and xylene (88 million pounds) were the VOCs
emitted in the largest quantities in 1996. Other high level or volume production-related waste
chemicals included: zinc compounds (209 million pounds), ammonia (193 million pounds), nitrate
compounds (169 million pounds), chlorine (67 million pounds), and hydrogen chloride (66 million
pounds).
"Strategies for Reducing Risk"
Three strategies can be employed to reduce VOC-related risk. The first strategy entails
remediating the contaminated media (land or groundwater) using a treatmentldestruction
technology such as bioremediation. In general, recovery technologies are not considered for
remedial efforts because the recovered contaminant rarely has reuse value.
The next strategy for reducing VOC-related risk involves the use of control technologies, like
incineration or catalytic oxidation, to treat pollution (e.g., VOC emissions). In general, destruction
technologies are employed to deal with "end-of-pipe" emissions.
The third strategy involves using pollution prevention techniques to prevent the generation of a
pollutant. This can be accomplished by: 1) employing material substitution, material avoidance,
and process changes (e.g., substitute an aqueous solvent for a chlorinated solvent); or 2)
recycling/reusing materials (e.g., methylene chloride recovery from polycarbonate manufacture,
solvent recovery from paint spray booths, or in-process recycling of
reactants/byproducts/solvents).
All three strategic avenues are important for VOC management. Unfortunately, few conventional
technologies can efficiently remove, capture, or recover/reuse VOCs from low concentration
streams. The technical challenge faced by technology developers today is the development of
highly efficient, cost effective VOC recovery methods (e.g., low-cost designer sorbents with high
capacity or pervaporation, which are capable of transforming dilute streams into highly
concentrated streams). To support this effort, seminar participants were encouraged to identify
currently available technologies, technologies that appear promising, and technologies that are
coming in the near future.
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VOCs: Sources, Definitions, and Considerations for Recovery
Presented on September 16, 1998 by Carlos Nunez, U.S. EPA NRMRL
This presentation gives an overview of major VOC sources and general considerations for product
recovery, including several basic and pertinent definitions.
Definitions
VOCs are defined as "any compound of carbon, excluding carbon monoxide, carbon dioxide,
carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in
atmospheric photochemical reactions." If, however, the photochemical reactivity of an organic
compound is negligible (e.g., less than the reactivity of ethane), it can be excluded from
classification as a VOC. Furthermore, once a compound is classified as a VOC, its specific
reactivity becomes irrelevant from a recovery/control perspective since the regulatory mandates
(and the resulting recovery/control systems) focus on total VOC reduction goals, which fail to
weight individual compounds based on their reactivities.
Originally four compounds were classified as negligibly reactive (methane, ethane, methyl
chloroform, and trichlorotrifluoroethane). Since 1977, 42 compounds or classes of compounds
have been classified as negligibly reactive and added to the exempt list. Most of the exemptions
were determined by comparing the kOH value of the compound of interest to the kOH of ethane.
[Note: kOH is the reaction rate constant for the reaction of a compound with an hydroxyl (OH)
radical.] In 1993, however, EPA began evaluating exemption petitions based on the maximum
incremental reactivity (MIR) of a compound. MIRs, which focus on the mechanistic aspects of
atmospheric reactions, are calculated based on the grams ozone produced per gram of compound
reacted; acetone was the first compound evaluated for exemption using MIR. Currently 15
exemption petitions are being processed.
Major VOC Sources
Based on 1996 data, processes that involve solvent utilization are responsible for 33% of the
VOCs released to the atmosphere. The remaining 67% is provided by the following sources: 29%
from on-road vehicles, 13% from non-road vehicles, 7% from storage and transport activities, 3%
miscellaneous, and 15% from other sources (i.e., fuel combustion, chemical and allied product
manufacturing, metals processing, petroleum and related industries, waste disposal and recycling,
and other industrial processes). Since approximately half of the releases associated with solvent
utilization can be attributed to various coating operations, EPA Research Triangle Park has
targeted this area for further research.
It should be noted that the VOC levels in 1996 represent total estimated reductions of 7% and
38%, respectively, from 1995 and 1970 levels. This can be attributed in part to significant
emissions reductions in the mobile sector due to uniform nationwide controls. (Note: Vehicle
emission rates were reduced by approximately 90%, compensating for population increases and
the two-fold increase in the number of vehicle miles traveled.) It should also be noted that VOCs
from natural sources are almost equal to anthropogenic emissions; however their atmospheric
impacts are unknown.
Considerations for Product Recovery
Technical feasibility and economic feasibility must be accounted for when considering product
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recovery. In order to determine the technical feasibility of a process, the following parameters
need to be evaluated: 1) recovery efficiency (regulatory requirement); 2) product quality (process
requirement); 3) the product's physical and chemical characteristics (e.g., vapor pressure,
molecular weight, polarity/solubility, and molecular size); and 4) emission stream characteristics
(e.g., flow rate, concentration, temperature, moisture, contaminants). The economic feasibility of
a process can be determined by:I) identifying the capital and operating costs (recovery,
destruction, and new); and 2) comparing annualized costs to virgin material costs and the costs
of other treatment or disposal options. To be considered economically feasible, recovery costs
must be less than disposal/destruction and makeup material costs. Ultimately, the process chosen
to control a VOC stream will need to balance technical and economic goals/limitations to meet
environmental and corporate requirements.
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Overview of VOC Recovery Technologies
Presented on September 16,1998 by Kamalesh Sirkar, New Jersey Institute
of Technology (NJIT)
After providing some background information on recovery technologies, vapor- and aqueous-
phase VOC recovery processes were discussed. Emphasis was placed on vapor-phase
processes, since the majority of aqueous-phase systems are well known.
Background Information
References - Although there is a lack of consolidated sources of VOC recovery studies, the
following references were identified as useful resources:
J.L. Humphrey and G.E. Keller, II, "Separation Process Technology," McGraw Hill, New York,
Chapter 7 (1987).
N. Mukhopadhyay and E. C. Moretti, "Current and Potential Future Industrial Practices for
Reducing and Controlling Volatile Organic Compounds," Center for Waste Reduction
Technologies (CWRT), American Institute of Chemical Engineers (AlChE) (1993).
Papers Presented in "Zero Discharge Manufacturing: Removal of Organics from Air I, II, III,"
Sessions 26, 27, and 28. Preprints of Topical Conference on Sep. Sci. and Tech., AlChE
Annual Mtg., Part II, Los Angeles, CA, Nov. 16-21 (1997).
Definition - VOCs can be defined as organic chemicals with a vapor pressure of more than 0.1
millimeter of mercury (mm Hg), at 20 degrees Celsius ("C) and 760 mm Hg, which participate in
atmospheric photochemical reactions. This definition excludes carbon monoxide, carbon dioxide,
carbonic acid, metallic carbides or carbonates, and ammonium carbonate. Over 318 compounds
have been classified as VOCs. These compounds contribute to an annual VOC emission rate of
8.5 to 17 million metric tons per year (from stationary sources) and an annual energy loss of 450
to 900 trillion British Thermal Units (BTUs) per year (approximately 3% of the total net U.S.
industry usage).
Industry Perspective-A CWRT study by Mukhopadhyay and Moretti (1993) yielded the following:
Information on process vents, wastewater operations, storage tanks, transfer operations, air-
stripping operations, purge streams, devolatilization operations - Maximum Achievable Control
Technology (MACT) standards.
Information on the reduction of aliphatic, aromatic, and halogenated hydrocarbons as the
primary VOCs emitted; also significant amounts of alcohols, ethers, glycols, etc., were emitted
User survey results indicating that users spend 40% of their capital expenditures on streams
with flows near 500 standard cubic feet per minute (scfm). This indicates that it is time to
redirect research towards small flow streams since lower flow streams apparently command
a substantial portion of the market. Additionally, the CWRT study notes that 80% of user
capital expenditures are for streams with flows less than 5,000 scfm, an area which most
developers are focusing on.
User survey results indicating that users spend 90% of their capital expenditures on VOC
streams with VOC concentrations from 500 to 10,000 parts per million (ppm). Additionally,
50% of their capital expenditures are for VOC streams with concentrations from 1,000 to
5,000 ppm and 8% of their capital expenditures are for lean VOC streams with concentrations
less than 500 ppm.
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Supplier surveys indicating that 40% of their total sales are attributed to adsorbers.
Basic Principles - In-plant gaseous stream sources (air/nitrogen) are often too numerous for
collection and treatment by a central facility/process. In-plant liquid sources are also numerous;
however, these streams are usually collected for centralized cleanup. Additionally, when gaseous
streams are treated, aqueous streams are often produced (and vice versa); thus a clear-cut
distinction between treatment of gaseous and liquid streams is not always possible.
Vapor-Phase Systems
Gas-phase VOC recovery is typically accomplished using phase change processes (e.g.,
distillation or condensation) or mass separating agent-based processes, including equilibrium-
based processes (e.g., adsorption, absorption, and membrane-based absorption) and rate-
governed membrane processes (e.g., vapor permeation). Generally, however, most processes
are hybrid processes, consisting of at least two separation techniques.
Adsorption and Regeneration Processes - Activated carbon, synthetic resin beads (styrene
divinylbenzene polymers), zeolites, and aerogels (which are regenerable at 50ฐC) are among the
different types of adsorbents available for VOC recovery. Although activated carbon provides
excellent adsorption, regeneration can be difficult. Furthermore, activated carbon has poor
stability, humidity control problems, and is chemically reactive with certain contaminants (e.g.,
causing bed fires from ketones, aldehydes, etc.).
When adsorption is used for VOC removal, the adsorbent can be regenerated using thermal
regeneration, pressure swing adsorption (PSA), or with purge gas. A variety of thermal
regeneration processes are available, including steam, hot nitrogen [450 degrees Fahrenheit (OF) -
BOC - AIRCO], microwave, infrared (for fixed beds), rotary wheels (for traveling beds), and
fluidized beds, A schematic of a fixed-bed adsorption process for recovery of acetone for air and
an adsorbent wheel with monolithic adsorbent were presented as examples of adsorption systems.
Fluidized Bed Systems - The Polyadฎ Process was presented as an example of a continuous
fluidized bed process. This process utilizes a separate adsorber and desorber and a highly
abrasion resistant, macroporous, polymeric pellet called Bonopore. During operation, particles
are pneumatically transported from the adsorber to the, desorber, where they are regenerated
using steam-heated, air-based desorption. The recovered VOCs are condensed using cooling
water. These units typically treat 35,000 cubic meters per hour (m3/hr) vapor streams, but have
a 500 to 500,000 m3/hr range. Additionally, special hydrophilic adsorbents (Optiporeฎ) can be
used for streams containing water vapor for adsorbing formaldehyde.
A schematic of a Sorbatheneฎ-DOW PSA process was presented to highlight some of the
characteristics of a PSA system. Although activated carbon PSA processes have been used in
90% of all gasoline vapor recovery systems installed at fuel loading terminals, including 1,000
locations in the U.S. and 500 international locations there is a general misconception that PSA
has to be performed using polymeric adsorbent. Because only adsorbents with high butane
working capacities can be used (e.g., greater than 0.065 grams per cubic centimeter), only 4 of
150 activated carbon adsorbents have appropriate retentivity (i.e., two wood-based and two coal-
based). Typically these systems have to meet 10 milligrams hydrocarbon per liter (mg HC/liter)
and demanding regeneration vacuum requirements, [Note: The German limit is 150 milligrams of
hydrocarbon per normal cubic meter (mg HC/Nm3), 65 times lower than the U.S. EPA limit]
Furthermore, they primarily adsorb non-(CH,, C2H5) VOCs, such as C4H10, C5H12, C6H14, etc.
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Absorption - Absorption processes should be selected based on the characteristics of the VOC
to be treated. Since water can act as an absorbent as long as an azeotrope is not formed,
conventional towers should be used to treat hydrophilic VOCs. If a hydrophobic VOC requires
treatment, membrane-based absorption and stripping using heavy hydrocarbon absorbents is
probably appropriate. A schematic of an absorption process for recovering acetone from air was
presented,
Membranes - During membrane permeation, the VOC permeates through a VOC-selective,
rubbery membrane composed of polydimethylsiloxane or polyoctylmethylsiloxane, leaving the
nitrogen and air behind. These membranes come in a number of configurations, including spiral-
wound modules (from MTR, Inc.), round flat sheet membranes in a membrane envelope (from
GKSS, Inc.), and hollow fiber membranes having plasma-polymerized silicone membranes (from
AMI, Inc.). Typically, membrane systems contain a condenser, compressor, and a membrane.
The flow diagrams developed for these systems are determined by compression, condensation,
and membrane hybrid configurations. Three membrane process schematics highlighted some of
the different configurations possible with membrane systems: 1) membrane-based absorption and
stripping process; 2) flow swing membrane permeation; and 3) vacuum driven vapor permeation
process.
Condensation - A schematic of a condensation system for removing acetone from air and a
schematic of the Kryoclean VOC control system served as an aid to visualize condensation
systems.
Process options for removing VOCs from vent streams are summarized in Table 1.
Table 1. Process Options for Removing VOCs from Vent Streams
Process
Membranes
PSA
Temperature swing
Adsorption/Fixed Bed
Moving/Fluidized Beds
Wheel-Based
Absorption
Refrigeration/Cooling
Freezing with Liquid Nitrogen
Maximum Pollutant Concentration
(mole % in feed,
except where indicated)
nearly unlimited
20 to 40
a few %
a few %
1,000 to 5,000 ppm
nearly unlimited
unlimited
unlimited
Maximum
Removal
(%)
90 to 98
greater than 99
greater than 99
90 to 98
98
90 to 98
50 to 75
greater than 99
A comparison of vapor-phase VOC recovery technologies, based on air feed rates and acetone
concentrations, indicates the following:
Membranes are appropriate for high concentration (greater than 2% acetone), low flow rates
(from 100 to 1,000scfm)
Absorption technologies are appropriate for high concentration (greater than 2% acetone),
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medium to high flow rates (from 1,000 to 10,000 scfm), and for low to medium concentration
(0 to 2% acetone), high flow rates (greater than 2,000 scfm)
PSA is appropriate for low concentration (less than 0.3% acetone), low to medium flow rates
(from 100 to 2, 000 scfm).
This comparison also indicates that a number of technologies (e.g., membranes, PSA, etc.) are
competing against each other for the medium concentration (0.3 to 2% acetone), low to
medium/high flow (100 to 2,000 scfm) streams.
Aqueous-Phase Systems
Aqueous-phase VOC recovery is typically accomplished using phase change processes, filtration
processes, or mass separating agent-based processes. Appropriate mass separating agent-
based processes include equilibrium-based processes (e.g., adsorption and stripping) and rate-
governed membrane processes (e.g., pervaporation). Like gas phase systems, most processes
are generally hybrid processes, consisting of at least two separation techniques. An aqueous
VOC recovery which employed a combination of several processes (stripping, adsorption, etc.)
was shown to illustrate prevalence of hybrid systems for dealing with aqueous phase VOC
recovery.
Stripping - A schematic of an open- and a closed-loop stripping/adsorption system was used as
an introduction to stripping processes. Steam- or air-stripping effectiveness can be evaluated
using the following equation:
where,
K" = the dimension less Henry's Law constant
Y = gas phase mole fraction
x = liquid phase mole fraction
fฐ = fugacity, which can be approximated by the vapor pressure
Y = infinite dilution activity coefficient
P = total pressure.
Contaminants with a !og10K~ which is greater than -2 and less than 2 tend to be highly hydrophilic,
low molecular weight compounds which are difficult to strip (e.g., ethylenediamine, ethylene glycol,
formaldehyde, acetic acid, phenol, methanol, acetone, 1-butanol, and ethyl acetate).
Contaminants with a log10K" greater than 2 are usually easier to strip (e.g., methylene chloride,
chloroform, benzene, toluene, carbon tetrachloride, vinyl chloride, and l-hexane).
Surfactant-enhanced carbon regeneration is an interesting technology in which the organic-
saturated column is regenerated first with sutfactant and then with water. The surfactant rinse
produces a surfactant/organic stream; the water rinse produces a water/surfactant stream.
Pervaporation - Pervaporation processes are also used to remove organics from aqueous
streams. Table 2 contains typical VOC/water separation factors for pervaporation. Surfactant
enhanced aquifer remediation for surfactant recovery can also be employed during soil
remediation. This application of the technology was discussed by Leland Vane in another session.
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Table 2. Typical VOC/Water Separation Factors in Pervaporation
VOC/Water Separation Factors {Volatile Organic Compounds
greater than 1,000
100 to 1,000
10 to 100
1 to 10
Benzene, ethyl benzene, toluene, xylenes,
trichloroethylene, chloroform, vinyl chloride, ethyl
dichloride, methylene chloride, perfluorocarbons, hexane
Ethyl acetate, ethyl butyrate, hexanol, methyl acetate,
methyl ethyl ketone
Propanol, butanol, acetone, amyl alcohol, acetaldehyde
Methanol, ethanol, phenol, acetic acid, ethylene glycol,
dimethyl formamide, dimethyl acetamide
Hybrid Process - A variety of hybrid processes can be used for wastewater treatment including:
1) air-stripping followed by activated carbon adsorption of the stripping air; 2) steam-stripping
followed by condensation; 3) activated carbon adsorption followed by steam-stripping; and 4)
solvent extraction followed by distillation. Additionally, wastewater from stream-stripping can be
treated by reverse osmosis and concentrated for recovery by pervaporation.
A comparison of aqueous-phase VOC recovery technologies, based on feed rates and VOC
concentrations, indicates the following:
Chemical oxidation, ultraviolet (UV) destruction, or air stripping/carbon adsorption are
appropriate for low concentration (from 0.001 to 0.01% VOC), low to high flow rates (from 0.1
to 1,000 gallons per minute, or gpm)
Pervaporation is appropriate for medium concentration (from 0.01 to 10% VOC), low to
medium flow rates (from 1 to 100 gpm)
Steam stripping is appropriate for medium concentration (from 0.01 to 10% VOC), medium
to high flow rates (from 10 to 1,000 gpm)
Distillation and incineration are appropriate for high concentration (from 10 to 100% VOC),
low to high flow rates (from 0.1 to 1,000 gpm).
Conclusions
Need comparative economics and evaluation for air/nitrogen streams having: 1) large flow
rates, 2) hydrophobic VOCs, and 3) hydrophobic and hydrophilic VOCs
Need comparative economics and evaluation for aqueous waste streams utilizing different
processes (e.g., stripping, reverse osmosis, pervaporation, solvent extraction, and distillation)
and combinations of processes
Need compact and flexible devices for vents from small-scale equipment
Need more VOC-selective pervaporation membranes for polar VOCs
Need membrane-based, compact and cheaper steam strippers
Need selective and stable adsorbents that are strippable using small temperature changes
Need to continue to improve PSA processes.
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Industrial Research Programs
Presented on September 16,1998 by Edward Moretti, Baker Environmental
This presentation gives an overview of new applications, developments of existing technologies
and innovative technology developments. Although the seminar emphasizes VOC recovery, both
recovery and destruction technologies were presented. This was done to ensure that the seminar
participants were aware of the technologies that recovery processes compete against, both
technically and economically. Volume reduction technologies were not discussed, since these
technologies have moved from research to application.
New Applications of Existing Technology
Membrane Separation - During membrane separation, contaminants are recovered from waste
process streams using permeable membranes. Membrane separation has been used in the past
for water quality management and has recently been used for air management, particularly VOC
recovery. Membrane separation is used to recover compounds that are not efficiently recovered
using adsorption and condensation, Membrane separation is increasingly being used for
halogenated solvents and is a good alternative for recovering expensive solvents.
Biofiltration - Biofiltration has been used frequently in Europe for odor control and is currently
expanding into a number of other areas. During biofiltration, VOCs are destroyed in biologically
active filter beds. The technology has a 50% success rate for sustained operation and some
success with gasoline and benzene, toluene, and xylene (BTX) vapor streams. It also has low
operating costs and energy usage.
Photochemical Destruction Technologies - Photochemical destruction technologies destroy
VOCs using UV radiation and oxidants. In general, this technology has limited commercial
application.
New Developments Using Existing Technologies
New Adsorbents - Adsorbents other than granular activated carbon are currently being developed
including zeolites, polymers, and carbon filters. In addition to treating a larger number and range
of VOCs, these adsorbents offer improved performance for high boiling point compounds, humid
vapor streams, and exothermic adsorption.
Newer Bed-Reoeneration Options - A number of newer bed regeneration options have been
developed, including the following:
Refrigeration (e.g., Brayton Cycle Systems)
Solvents (e.g., acetone, methanol)
Vacuum (e.g., PSA)
Inert gases (e.g., nitrogen)
Resistive electrical heating
Microwave heating.
Resistive electrical heating and microwave heating both use the electrical characteristics of the
adsorption material (carbon or other) to regulate the temperature of both the adsorption material
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and adsorbed compounds.
New Packing Materials and Cryogenic Fluids for Condensation - Research continues on new
packing materials to reduce fouling and on cryogenic fluids for condensation (e.g., liquid nitrogen
and liquid carbon dioxide).
Innovative Technology Developments
Totally New Concepts and Market Drivers - The destruction of VOCs using ionized gas (e.g.,
plasma) is a relatively new concept. The plasma is a high temperature ionized gas that reacts with
VOCs to form carbon dioxide, hydrogen, and water. Corona discharge plasma reactors and
electron beam reactors are also being developed. The VOC innovative technology market has
been driven by the type and concentration of VOCs encountered in exhaust streams, exhaust
stream flow rates (e.g., high concentration, low flow rate streams are well suited), and regulatory
pressure. Emphasis has been placed on developing technologies capable of treating more
difficult streams (e.g., multiple VOC streams, halogenated VOCs)
Benefits and Risks of Innovative Technologies - The benefits of using innovative technologies
include permit waivers (to accommodate these technologies as they are developing) and
demonstration co-funding. The risks associated with using innovative technologies include
unknown operation and maintenance (O&M) costs, scale-up problems (from bench to pilot to
commercial applications), unacceptable process changes, unknown waste generation costs,
unknown long-term operational reliability, and unknown long-term reliability to meet regulatory
performance standards. These challenges can be met by technologies capable of demonstrating
technical feasibility and attractive economics.
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VOC Recovery Research at EPA Office of Research and
Development (ORD)
Presented on September 16, 1998 by Teresa Hat-ten, U.S. EPA NRMRL
The Clean Products and Processes Branch at U.S. EPA NRMRL uses the risk management/risk
assessment paradigm to prioritize its research efforts. This approach was recommended by the
Science Advisory Board which is responsible for reviewing EPA's research. EPA NRMRL in
Cincinnati, Ohio focuses on the risk management facet of the paradigm, while the other three
laboratories in ORD focus on risk assessment.
EPA NRMRL in Cincinnati, Ohio is currently concentrating its research efforts on pervaporation,
temperature swing sorption, and pollution prevention tools. These efforts are summarized below.
Pervaporation
Pervaporation combines permeation and evaporation to transfer contaminants from a liquid stream
through a non-porous VOC-selective membrane to an inert gas vapor stream. Pervaporation
research at EPA NRMRL in Cincinnati originated from a joint EPA/Department of Defense (DOD)
effort to identify/develop a technology capable of remediating contaminated groundwater at DOD
sites. EPA NRMRL has begun an industrial pollution prevention pervaporation research project
designed to investigate regeneration of cleaning alcohols using dehydration. (Note: Cleaning
alcohols are being used by a number of facilities as an alternative to chlorinated solvents.) Other
EPA NRMRL research projects are described in the following subsections.
Remediation Fluid Recycling - A DOD-sponsored effort that is discussed in detail in Leland Vane's
presentation "Dehydration and VOC Separation by Pervaporation for Remediation Fluid
Recycling."
Pervaporation Performance Prediction Software and Database (PPPS&D) Development -
Version 1 of the software program contains a tutorial to educate the user, a research database
developed using research and commercial data, and numerical and other models which can be
used to predict bench-scale performance. Version 2 , which will be used to predict pilot-scale
performance, and Version 3 , which will be used to estimate pilot unit costs, will be developed
under a Cooperative Research and Development Agreement (CRADA) with Mempro, a privately
owned software company.
Polymer/Ceramic Composite Membrane Development-These membranes can potentially operate
at separation factors of 3,000 to 10,000.
Conductive Membranes and Films for Separation Processes - Electric currents are used to heat
the separation membranes using resistive heating, thereby encouraging contaminant vaporization.
Temperature Swing Sorption
Like pervaporation, temperature swing sorption research at EPA NRMRL in Cincinnati started as
a DOD-funded effort. In this case, however, the DOD was interested in identifying/developing a
technology which would be capable of recovering VOCs from paint spray booth streams (which
typically contain water vapors). Temperature swing sorption uses a polymeric sorbent material
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instead of carbon to separate contaminants from a process stream. Unlike traditional adsorption
(during which the contaminated air is heated and cooled cyclically), only the sorbent, not the air
stream, is cooled during the sorption phase; this increases both capacity and efficiency. Also,
regeneration is completed in place and the presence of water vapor should not affect capacity.
The technical objective of this research is to develop a cost-effective technology for recovering
VOCs from paint spray booth exhausts. Recovery becomes viable when low VOC coating
formulations can not be used or when reductions are mandated by a State Implementation Plan
(SIP).
Pollution Prevention Analytical Tools Development
EPA ORD is currently developing process simulation software (waste reduction algorithm) which
can be used as an add-on package to commercial software programs. This software can be used
to predict waste generation from various process configurations, which can be modified by the
user. EPA ORD is also developing a number of life cycle tools for inventory and impact
assessment. These tools can be used during technology development to assess relative
environmental impacts of various chemicals/wastes (e.g., ozone depletion, global warming, and
human and ecological toxicity).
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Short Flow Path Pressure Swing Adsorption - Lower Cost
Adsorption Processing SHERPA
Presented on September 16, 1998 by William Asher, SRI International
SHERPA is a short flow path PSA process which can be used for lower cost adsorption
processing. With this process, the flow path is reduced from several feet to a fraction of an inch.
By reducing the flow path, the size of the unit used to remove VOCs is decreased by a factor of
100. This results in lower capital costs and space requirements.
The PSA cycle has three steps: 1) pressurization, 2) high pressure flow, and 3) depressurization.
During the pressurization step, VOC adsorption begins as process air (usually at a vacuum) flows
into the adsorber through an open valve at the bottom of the unit. Since the outlet valve located
at the top of the unit is closed, pressure continues to build as process air enters the unit. Once
atmospheric pressure is achieved, the outlet valve is opened and the second step in the cycle,
high pressure flow, begins. During high pressure flow, both the inlet and outlet valves remain
open. During this step, contaminated air enters the unit, is cleaned by the adsorber, and exits
through the outlet valve. Step 3, depressurization, begins after the adsorbent has become
saturated with contaminants. During this step the exit valve is closed, and contaminants are
removed from the adsorbent through the valve at the bottom of the adsorber. As depressurization
continues, the pressure in the adsorber decreases to vacuum levels and the feed and adsorbate
flows decrease to close to zero.
Conventional PSA beds are approximately 5 to 20 feet long and contain evenly distributed
adsorbent particles. They can be as large as one eighth of an inch in diameter in order to limit the
pressure drops across the beds. Prior hollow fiber PSA contactors use hollow fibers to lower the
pressure drop across the length of the 'bed. As a result, smaller particles can be used with this
configuration.
Although these prior hollow fiber systems are more efficient than conventional PSA beds, their
efficiency is limited by the diffusion of contaminants from the hollow fibers to the external surface
of the adsorbent particles. To address this limitation, every other fiber has been blocked in newer
hollow fiber systems, causing process air to enter the bed through one set of fibers/tubes and flow
through adsorbent particles to the adjacent fibers, where the process air is transferred out of the
system. With this configuration, the most distant particles are utilized and there is no selectivity
for the fibers. As a result, the flow path drops from several feet to a fraction of an inch.
The reduction in flow path experienced using the newer hollow fiber configuration results in
tremendous cost and performance advantages. In addition to being able to use particles as small
as 20 microns in diameter, both the cycle time and the bed size are reduced by a factor of up to
100. This results in a much smaller and lower cost unit. Also, diffusion to the adsorbent is no
longer the limiting step in the process. (Note: Bed size is directly proportional to cycle time.)
According to the developer, the new paradigm is different in kind and concept from all previous
hollow fiber adsorbers and all previous rapid cycle PSAs. Additionally, the feasibility of the new
contactor has been experimentally established.
The contactors are composed of a woven "mat" which is rolled up and placed within a case. The
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mat is composed of sorbent, solid filaments, porous hollow elements with sealed ends, and an
impermeable layer. The contactors can be manufactured using Celgardฎ fiber, fabric, a center
tube with a central plug, and resin.
The newer PSA systems can be used for the removal and/or recovery of VOC (using established
and new adsorbents) and natural gas (using natural gas liquids, water, and acid gases). It can
also be used for separations on petrochemical light ends and to remove and/or recover a number
of other gases. As SRI approaches commercial application of this system, they have recently
entered into discussions with hollow fiber producers/module fabricators and valve manufacturers
for less than l-second valves. The system is particularly applicable to new sorbent systems under
development.
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Solvent Recovery Applications at 3M
Presented on September 16,1998 by James Carmaker, 3M Corporation
This presentation is divided into two main components: an overview of solvent recovery
applications at 3M and a case study based on real data.
Solvent Recovery Applications at 3M
3M has 110 VOC air pollution control systems worldwide: 85 thermal oxidizers and 25 solvent
recovery units. The first systems were installed in the1970s. In 1987 the Air Emission Reduction
Program (AERP) became global corporate policy. Under this policy all sources which emit more
than 100 tons per year must meet local government standards and AERP requirements of 81%
control for existing sources and 90% control for new sources. Since AERP's adoption, emissions
have dropped from over 100,000 tons per year in 1990 to just over 20,000 tons per year in 1997.
To date, 3M has invested approximately $260 million in VOC control systems and received the
following awards:
1996 - President's Sustainable Development Award for 3P Program
1995 - Environmental Champions Award for Air Emission Reductions (U.S. EPA)
1995 - Energy Efficiency Award for Brayton Cycle Solvent Recovery Systems (Alliance to
Save Energy).
1991 - Stratospheric Ozone Protection Award (U.S. EPA)
1991 - Winner of the President's Environment and Conservation Challenge Award Citation.
3M currently uses 15 carbon adsorption systems (13 which employ steam regeneration and 2
which use inert gas regeneration), 10 inert gas condensation systems (which condense solvents
on cooling coils), and 5 liquid wet scrap distillation systems (which recover solvents from
hazardous waste). The carbon adsorption process airflows range from 6,000 to 102,000 scfm
and the inert gas condensation process solvent rates ranges from 5 to 900 pounds per hour
(Ibs/hr). Hexane, heptane, toluene, naptha, ethanol, isopropyl alcohol, ethyl acetate, methyl ethyl
ketone, cyclohexanone, and carbon disulfide are among the solvents recovered with 3M's solvent
recovery systems.
In general, 3M favors solvent recovery applications with the following characteristics:
High VOC usage rates
Fixed solvent blends (to ensure cross-contamination does not occur)
Reuse solvent in process
High solvent value
Continuous operation (to provide enough payback to justify the higher costs).
Solvent Recovery Case Study (3M Hutchinson, Minnesota)
The 3M Hutchinson, Minnesota facility is an audio/video tape manufacturing facility which utilizes
methyl ethyl ketone, toluene, and cyclohexanone during production. In 1990, 3M installed a
solvent recovery plant at this facility which uses carbon adsorption, steam regeneration, and
solvent distillation.
The solvent recovery plant is a continuous process which operates, with the help of two operators,
24 hours a day, 360 days per year. The plant is designed to process 102,000 scfm of
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contaminated process air and recover 5,100 pounds of solvent per hour. The recovered solvent
is composed of methyl ethyl ketone (55%), toluene (30%), and cyclohexanone (15%). The system
is designed to yield a recovery efficiency of 99% and to produce a recovered solvent which is 99%
pure.
During adsorption (which lasts 132 minutes) 75,000 scfm of solvent-laden air is typically
processed. Once the adsorption cycle is complete, the regeneration cycle begins. During
regeneration (which lasts 40 minutes) 16,500 Ibs/hr of steam are introduced to the adsorbers.
The regeneration phase is then followed by a cooling phase (which lasts 23 minutes), during which
14,000 scfm of ambient air is introduced to the adsorbers.
The adsorption plant performance can be summarized as follows:
Processes 75,000 scfm of solvent-laden air with a temperature of 95ฐF and 45% R.H.
Produces 2,800 pounds of solvent per hour
99.5% adsorption efficiency
4 to 10% carbon working capacity
Generates 5 to 8 pounds of steam for every pound of recovered solvent.
The reaction chemistry of the system also results in the formation of diacetyl and adipic acids
(from methyl ethyl ketone oxidation) and the potential for a ketone-related fire at carbon monoxide
concentrations below 5 ppm.
The distillation process employed at the 3M Hutchinson, Minnesota facility generates 67,000
pounds of solvent per day. During the distillation process, water/solvent separation is performed
using decanters and wastewater stripping columns. The separated solvent is then neutralized
using a wash column and distilled using dehydration, methyl ethyl ketone, toluene, and
cyclohexanone columns.
As of May 1998, 1,610,751 pounds of methyl ethyl ketone, toluene, and cyclohexanone were
recovered by the plant's solvent recovery system. Overall, 99.4% of the recovered solvents were
later applied at the plant. The net percent of recovered solvent applied was 101.7%, 99.9%, and
90.1% for methyl ethyl ketone, toluene, and cyclohexanone, respectively.
The solvent recovery system was started in 1990 and temporarily shut down in 1991 following an
adsorber carbon bed fire and adsorber implosion. The process was later reformulated in 1993 to
reduce chloride production. In 1997 the MACT modifications were installed. These modifications
included 41 mixing kettle vents, 3 wash tank vents, and 20 solvent recovery vents (15
tanks/vessels and 5 distillation columns).
Capital costs for this system totaled $23,400,000. This total includes $19,500,000 for installation,
$2,500,000 in recommissioning, and $1,400,000 in MACT modifications. Annual operating costs
averaged $3,300,000. Approximately 13,200,000 pounds of methyl ethyl ketone; 7,200,000
pounds of toluene; and 3,600,000 pounds of cyclohexanone were recovered per year. The total
value of the recovered solvent equaled $7,968,000 (i.e., $5,016,000 for methyl ethyl ketone;
$1 ,1 52,000 for toluene; and $1,800,000 for cyclohexanone).
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The Economics of Recovery: Using the Office of Air Quality,
Planning, and Standards (OAQPS) Cost Manual as a Tool for
Choosing the Right Reduction Strategy
Presented on September 16, 1998 by Dan Mussatti, U.S. EPA OAQPS
The OAQPS Cost Manual is one of the principal engineering tools for predicting/assessing control
costs. It was developed by the Innovative Strategies and Economics Group within the Air Quality
Strategies and Standards Division in OAQPS. The manual is available on the Technology
Transfer Network (TTN) web page at http://www.epa.gov/ttn/catc/products.htmi#cccinfo.
The OAQPS Cost Manual frequently serves as a reference and template for other cost manuals
produced within and outside the EPA. It is designed to be general in nature, rather than control-
or vendor- specific. It provides information on "how" a control works and costs incurred using the
control. The level of detail contained in the OAQPS Cost Manual is rigorous and complete,
particularly in regard to smaller costs that are easily overlooked. The OAQPS Cost Manual is
designed for estimating costs for regulatory development [Regulatory Impact Analysis (RIA) etc.].
Although it does not cover every situation, it contains default assumptions that can be customized
to fit a specific situation better.
The OAQPS Cost Manual is an evolving document which is presently under review/revision. It
currently contains eleven chapters, with two new chapters forthcoming:
Introduction
General discussion of costs
Nine chapters on control devices (incinerators, flares, adsorbers, filters, precipitators,
condensers, hoods, ducts, and stacks).
Nitrogen oxide (NO,) control devices (forthcoming)
Permanent total enclosures (forthcoming).
Plans have been made to include a chapter on compliance assurance monitoring and to also add
text throughout the document addressing the costs associated with retrofitting and process
uncertainty.
In addition to discussing traditional accounting costs (e.g., the types of costs seen on a financial
or profit/loss statement), the manual accounts for social costs, both tangible and intangible. Social
costs are more difficult to quantify than accounting costs and are frequently forgotten in traditional
cost evaluations. They consist of both tangible costs which can be measured to some extent
(increased morbidity/mortality due to pollution, property damage due to pollution, productivity
losses, and crop and livestock damage), and intangible costs (habitat loss, diminished biodiversity,
aesthetic loss, option values, and existence values) which are very difficult to place a monetary
value on. Accounting costs, on the other hand, are relatively easy to address and consist of
annual costs (direct and indirect, fixed and variable, and recovery and salvage) and investment
costs (land, capital, and salvage value).
Most firms are concerned with maximizing profits/revenues in the long-term and minimizing costs
in the short-term. Thus, in the short-term many firms want to select a control strategy that has the
lowest marginal cost of operation (i.e., the lowest cost of the next increment removed) over the
relevant range, while in the long-term they are more likely to choose a control strategy with the
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highest "net present value." Unfortunately, when comparing the marginal costs associated with
different "control" alternatives (e.g., a recovery process versus incineration), many companies fail
to account for the social costs associated with the alternatives (Resource Conservation and
Recovery Act costs, recycling revenues, etc.). This may cause a company to choose a non-
recovery-based system (e.g., incineration) based on an analysis which underestimates the
alternative's true and full cost.
The experiences of a graphics printing enterprise highlight how social costs impact control strategy
selections. This company originally used four different solvents as part of its operation, resulting
in a waste stream that could not be recovered for reuse and causing the owners to favor
incineration over traditional disposal alternatives (due to disposal-related regulatory liabilities). In
response to these issues, the printing company chose to reformulate its process so that only one
solvent was used (i.e., hexane). It then installed carbon adsorbers to recover the solvent for in-
plant reuse. Not only did it essentially become a net supplier of hexane, but the company was
also able to meet the discharge standards at a reduced compliance cost.
In this and other approaches being applied, a reduction strategy was selected after first examining
the facility outputs with regard to the following:
Identify the compounds in the effluent stream to be controlled
Determine whether the effluent stream has value
Determine whether the effluent stream contains toxic substances and, if so, whether those
toxic substance are valuable and identify their disposal requirements.
If the effluent stream contains toxic substances that have no value, then incineration is probably
the most cost-effective alternative. If, however, the effluent stream contains substances that have
salvage value (e.g., reuse potential), then alternative technologies for recapturing the substances
should be considered and their costs (i.e., net of salvage value) compared to the cost of
incineration.
Ultimately a system is chosen based on how much control is needed. The "bad news" is that "The
cost of reduction (control) is directly related to the level of reduction, and the level of reduction is
highly correlated to how many regulations apply to the industry." The "good news" is that there
is a new tool available, called the Air Compliance Advisor (ACA), that can be used to help end-
users solve complex air management problems.
ACA is a customizable decision support tool consisting of an integrated package of databases,
algorithms, and models. End-users can modify ACA by resetting the default values (e.g., formulas
and labor costs) to mimic specific situations. It is also a framework in which many models operate
(and many more can be added).
ACA was developed by the Strategic Environmental Research and Development Program
(SERDP) under a joint agreement between DOD, EPA, and DOE. It is composed of: data and
analysis algorithms; data libraries; chemical properties; regulatory data; a hierarchy of source
types; emission control technology information; pollution prevention information; and "suggestions"
data. It contains information on the following control technologies:
Carbon adsorbers (single bed and multiple bed)
Thermal incinerators (catalytic, recuperative, and regenerative)
Flares (self-supported, guy-supported, and derrick-supported)
Gas absorbers
Refrigerated condensers
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Wet scrubbers for particulate matter (PM) (venturi, impact)
Baghouses (pulse-jet, reverse air, shaker).
Plans are currently being made to also include information on other common VOC and NO,
controls.
ACA uses algorithms from AP-42, Water 8 documentation, and AQUIS. It can be used to
calculate actual and potential emissions rates and as a means of documenting emission factor
ratings and references (approximately 75% complete). ACA is available free of cost on the TIN
web site at http://www.epa.gov/ttn/catc/.
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Rotary Concentration and Carbon Fiber Adsorption
Presented on September 16,1998 by Ajay Gupta, Durr Environmental
Rotary Concentration
Rotary concentrators are a variation of conventional adsorption technologies which simultaneously
perform adsorption, desorption (using hot air), and cooling. They use a rotating cylindrical
honeycomb element that has been impregnated with adsorbent (carbon, zeolite, or a combination)
to separate contaminants from process streams.
Before entering the rotating honeycomb element, process air is first treated to remove particulate
(using a filter house, venturi scrubber, or electrostatic precipitator) and then forwarded through a
static adsorption unit (usually containing granular activated carbon). The majority of the process
air (approximately 90%) proceeds directly through the rotating element where approximately 95%
of the VOCs are removed by adsorption. A small portion (e.g., 5 to 10%) of the process air is used
to cool the honeycomb element. After exiting the element, the cleaned air is heated and re-
circulated through the rotating wheel in order to desorb VOCs from the element. The solvent-
laden air is then forwarded to a thermal oxidizer (recuperative, regenerative, or catalytic) for
thermal treatment for VOC destruction.
Rotary concentrators are typically used to treat high volume (5,000 to 600,000 scfm), low
concentration streams [less than 1,000 parts per million by volume (ppmv)] produced by paint
spray booths (automotive and others), printing operations, semiconductor applications, and
fiberglass plastic manufacturing operations. They have been used to concentrate/control a wide
range of VOCs, including alcohols, aliphatics, ketones, glycols, and chlorinated compounds.
Since process streams with less then ten or more organic components are rare, opportunities to
use rotary concentrators to recover solvents have been limited.
Rotary concentrators normally operate at process temperatures of less than 100ฐF and humidities
of less than 65% for carbon and less than 95% for zeolite. They are generally used to treat
process streams with concentrations of less than 1,000 ppmv in order to ensure that lower
explosive limits (LEL) are not exceeded. (Note: Typically the desorption air exiting the rotating
element is ten times more concentrated than the untreated process air entering the cylinder.)
These systems also operate at VOC removal efficiencies of 95% or greater.
Rotary concentrators can potentially be used for the following solvent recovery applications:
Pre-concentrator for a conventional solvent recovery system
Solvent recovery for VOCs with high LELs (e.g., for trichloroethylene at a concentration of up
to 80,000 ppmv)
In series to achieve concentrations which are 100 times greater than pretreated process air
concentrations. In addition to yielding much higher concentrations, these systems will also
be compact, light weight, have low pressure drops (4 to 5 inches water), and perform
continuous solvent recovery, (Note: A new design, which uses concentrators in series, has
been developed but has not yet been patented.)
Carbon Fiber
Carbon fiber solvent recovery systems are batch systems which sequentially perform adsorption,
desorption (with steam), and cooling. These systems use high capacity carbon fiber non-woven
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mats setup in a baghouse-like configuration to separate contaminants from process streams.
They have been used for the last 15 to 20 years in Germany and Japan; however, cost concerns
have limited their use in the U.S.
Carbon fiber systems are typically used to treat high concentration streams (greater than 1,000
ppmv) produced by chemical manufacturing operations, pharmaceutical facilities, printing
operations, and the painting and coating industry. They have been used to concentrate/control
a wide range of VOCs, including alcohols (excluding methanol and ethanol), aliphatics, aromatics,
ketones, glycols, and chlorinated compounds (including trichloroethane, methylene chloride, and
trichloroethylene). Carbon fiber systems can also effectively treat flows of greater than 1,000
scfm, with the average single unit treating up to 15,000 scfm. (Note: Carbon fiber systems are not
able to treat methanol and ethanol cost-effectively because carbon has a low capacity for these
compounds.)
Carbon fiber systems normally operate at process stream temperatures of less than 150ฐF and
humidities of less than 95%. They are generally used to treat process streams with concentrations
that are greater than 1,000 ppmv and generally operate at removal efficiencies of 90 to 98%.
Although the pressure drops and system removal efficiencies are similar to packed bed systems,
steam consumption is lower and the units generally weigh less and are smaller in size (i.e., smaller
footprints). The quality of the recovered solvent is also very high, in part because the carbon
fibers are relatively free of impurities.
Activated carbon fiber matrices also have far more micropores than granular activated carbon
pellets. This contributes to much faster adsorption and desorption kinetics experienced by carbon
fiber systems as compared to traditional granular activated carbon systems.
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Zeolite Adsorption and Refrigeration - CONDENSORB VOC
Recovery System
Presented on September 16,1998 by Jon Kostyzak, M&W Industries
The Condensorb System combines high control efficiency, mechanical simplicity, low
maintenance, low space requirements, and flexibility (e.g., changing solvents and flow rates) to
cost-effectively recover concentrated dry solvent.
The Condensorb System is a combination of fixed bed zeolite adsorption and mechanical
refrigeration condensation. This configuration allows the Condensorb System to treat large
volumes of process air with low solvent loadings cost-effectively. The system typically removes
95 to 100% of the VOCs and hazardous air pollutants (HAPs) (including alcohol, acetate, and
other water soluble solvents) from high flow rate process exhausts.
During treatment, process air is sent through a prefilter (as needed) to remove particulates before
entering the concentrator. The concentrator is composed of a number of zeolite cells/bed which
are responsible for removing the VOCs/HAPs from the process stream. During regeneration,
warm air is sent through the concentrator (one to two zeolite beds only) in order to recover the
VOCs/HAPs adsorbed by the zeolite beds. The ultra-low flow warm air used to regenerate the
zeolite beds produces a regeneration air stream highly concentrated in VOCs. Although relatively
dry, the regeneration air is sent through a drying stage after it leaves the concentrator to remove
any moisture which may have entered the concentrator with the process air. The regeneration air
is then forwarded to a mechanical refrigeration condenser, where it is chilled to 20 degrees below
zero. The recovered VOCs and HAPs are collected and the residual air forwarded to the
concentrator for final treatment.
Since steam is not used to regenerate the zeolite cells, the Condensorb System does not use
a boiler. This saves on space, capital investment, and energy costs. Boiler-related tasks, like
decanting and pH adjustment, are also avoided. Also the recovered solvent is relatively dry,
making it a more usable product.
Power costs are also lower than for traditional recovery or destruction systems since the
Condensorb System consumes little power and no fuel. Additionally, VOC or HAP recovery
allows the unit to achieve a return on the investment.
The Condensorb System has the following advantages and disadvantages as compared to a
traditional solvent recovery system:
Advantages
Recovered VOC/HAP adds economic benefit
No fuel consumption
No NO, production
Very low pressure drop
Relatively quiet
95% minimum recovery
Adsorption media easily replaced/updated
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Very high uptime reliability
Existing solvent recovery system can be retrofitted
Disadvantages
Particulate filtration may be needed
Inlet temperature is limited to 140ฐF (maximum).
A case study involving a flexographic printing operation demonstrates the economic payback that
can be achieved using the Condensorb System. This company currently has a 45,000 scfm
carbon solvent recovery system which needs to be updated to achieve an ethanol removal
efficiency of 95% or greater. With the present system, it currently costs $3.34 to recover a gallon
of solvent. This cost includes $1.57 per gallon to neutralize the recovered solvent.
By replacing the traditional solvent recovery system with the Condensorb System, a control
efficiency for ethanol of greater than 95% will be achieved at a lower recovery cost that is less
than $1.25 per gallon of recovered solvent. Also, at least 50 gallons of ethanol lost per day using
the traditional system can now be recovered using the Condensorb System.
An analysis of the cost and recovery estimates yielded the following "payback" results using the
Condensorb System:
Greater than 95% control of ethanol
132,000 gallons solvent recovered per year
$275,880 saved in annual recovery cost
$585,900 to install Condensorb System
25 month payback schedule.
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A Novel Fluidized Bed Concentrator System for Solvent
Recovery of High Volume, Low Concentration WC-laden
Emissions
Presented on September 16, 1998 by Edward Biedell, REECO
Technologies are needed which can economically and effectively recover or capture/destroy dilute
concentrations of VOCs contained in relatively large air flows emitted by industrial and
manufacturing facilities. A number of destruction and recovery technologies are available that can
potentially fulfill this need (e.g., thermal oxidation, catalytic oxidation, carbon adsorption, and
hybrid systems consisting of pre-concentration followed by oxidization or solvent recovery). This
presentation focuses on the applicability of fluidized bed pre-concentrators.
In general, a recovery technology like fluidized bed pre-concentration is selected if the solvents
requiring control are valuable and if they can be recovered economically. To determine this, the
following factors need to be considered:
VOC composition in the process exhaust
Value of the recovered solvent (i.e., is it greater than $0.30 per pound?)
Capital, operating, and maintenance costs.
Fluidized bed pre-concentrators are synthetic carbonaceous beds used to adsorb VOCs/solvents.
They are used to treat high volume (e.g., 10,000 to 500,000 scfm) process exhausts with VOC
concentrations of less than 300 ppm and temperatures of less than 120ฐF. Although less
common, fluidized bed pre-concentrators can also be used to treat exhausts with very low VOC
concentrations (10 to 20 ppm), as well as concentrations near 1,000 ppm. Their ability to treat
relatively high and low concentration streams effectively is strongly dependent, however, on the
characteristics of the stream and system design.
Fluidized bed pre-concentrators typically achieve 95 to 98% VOC destruction or solvent recovery.
They are also able to effectively handle lower inlet concentrations than regenerative thermal
oxidation (RTO) and can be used for solvent recovery, unlike fixed carbon beds or rotary wheels.
Fluidized bed pre-concentrators typically exhibit much higher air volume reduction factors (800 to
1,000:1) than fixed bed or rotary systems (10 to 30:1). The dramatic difference in volume
reduction factors is attributed to the use of inert desorbing gases (steam or nitrogen) instead of
air.
From a capital cost perspective, fluidized bed pre-concentrators consist of an adsorber and a
desorber. Adsorber size (and cost) is dependent on air flow; desorber cost is based on the
concentration of VOCs. In general, fluidized bed capital costs are close to the capital costs
associated with regenerative thermal oxidation, but less than rotary wheel systems. Their
operating costs, which are mainly limited to fuel and power costs, are much lower than
regenerative thermal oxidation (approximately 20%) and the same as, or lower than, rotary wheel
systems.
The beaded carbonaceous adsorbent (BCA) used in these units is a synthetic form of activated
carbon with the following characteristics:
Smooth, hard beads
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High surface area
Carbonaceous composition
Particle sizes ranging from 0.3 to 1 millimeter
Less than 2% per year attrition rates
Capable of on-site regeneration
Able to easily handle (adsorb/desorb) chlorinated VOCs and hexamethyldisilanes without any
adverse effects.
During treatment, process exhaust passes through a blower and enters the adsorber at the base
of the unit. The process exhaust is cleaned as it flows through the BCA pellets contained in the
upper portion of the adsorber. As process airflows up the adsorber, spent BCA pellets (i.e.,
saturated with organic compounds) exit the adsorber near its base. These pellets are gravity-fed
through a desorber where organic compounds are removed by a counter-current flow of steam
or nitrogen gas. The desorber is operated at or below the boiling point of the VOCs being
removed, usually between 400 to 500ฐF. The cleaned pellets are returned to the top of the
adsorber and the organic-laden air is forwarded to an oxidizer for destruction or to a solvent
recovery system for condensation.
Fluidized bed pre-concentration systems can potentially be used at semiconductor chip
manufacturing facilities, surface coating facilities (e.g., automotive, aerospace, furniture finishing,
and metal decorating), soil remediation sites, and solvent recovery locations/sites. They also
provide the following advantages for high flow, low VOC concentration applications:
High capture and destruction recovery potential
Lower energy consumption
Smaller footprint
Reduced weight (this allows them to be placed on rooftops)
High reliability
Safety.
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Recovery of VOCs by Microwave Regeneration of Adsorbents
Presented on September 16, 1998 by Philip Schmidt, University of Texas (UT)
at Austin
There is a lot of interest in recovering VOCs from low-concentration air streams. Currently many
companies use destruction technologies to treat low-concentration streams because they are more
cost-effective than commonly available recovery technologies (e.g., direct condensation, hot inert
gas regeneration of adsorbents, and steam-stripping of adsorbents). Unfortunately, when
destruction technologies are used, valuable materials and energy are often wasted. Microwave
regenerated adsorption systems may prove to be an appropriate, non-destructive alternative for
recovering VOCs from low-concentration streams.
Compared to the more common heat-based alternatives, microwave regeneration provides
improved recovery, enhanced heat/mass transfer rates, and improved control. The technology
requires little to no purge gas to produce a highly concentrated off-gas that can be easily
condensed. Unlike carbon bed systems which utilize steam regeneration, microwave regeneration
systems do not need to perform liquid-liquid separation, eliminating the difficulties associated with
separating water-soluble solvents. Because microwave energy does not require a medium for
transfer (it can heat in a vacuum), heat transfer rates depend solely on the available generator
power and are not limited by surface area or heating medium. VOC transport out of the adsorbent
is also dominated by pressure-driven flow and is not limited by molecular diffusion. The enhanced
heat/mass transfer rates achieved by microwave regeneration result in higher throughputs and
shorter cycle times.
UT at Austin has performed numerous microwave regeneration bench scale, process design, and
comparative cost design studies over the past 7 to 8 years. These studies followed the following
research approach:
Bench-Scale Experiments: For proof-of-concept and to obtain kinetics and sensitivity to
operating parameter data.
Process Design Studies: To evaluate alternative configurations, adsorbent selection, and to
estimate costs and equipment size.
Comparative Economic Feasibility Studies: To evaluate cost-effectiveness in selected
applications. These tests were performed at the pilot level, although a field test is planned.
UT at Austin is also planning a number of lab pilot column and field demonstrations to obtain
scale-up information and to assess compatibility with commercial environments.
Bench-Scale Experiments
Over 100 bench-scale experiments have been performed as a proof-of-concept and to explore the
desorption kinetics of microwave regeneration. In general, these tests were conducted using
stripping gas or under vacuum conditions (25 to 150 torr) and the desorbed solvents were
recovered by condensation. The following solvents and adsorbents were tested during these
experiments:
Solvents: Methyl ethyl ketone, toluene, n-propyl alcohol (nPA), water
Adsorbents: Molecular Sieve (MS) 13X, Dowex Optipore, MHSZ (a registered trademark
product of UOP).
A review of the bed temperature profiles for a conventional regeneration process (e.g., inert gas
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stripping in conventional adsorbent beds) versus microwave regeneration indicates that microwave
regeneration heats more uniformly and more rapidly than conventional systems. Microwave
regeneration systems also tend to reach higher temperatures. The desorption effluent
concentration profiles indicate that microwave regeneration leads to a much faster evolution of the
solvent from the adsorbent.
UT at Austin also performed bench-scale experiments to determine how well, microwave
regeneration works using a number of different adsorbents. During these tests, UT at Austin
measured the dielectric loss factor of a number of different adsorbents and solvents. (Note: The
dielectric loss factor measures how effectively a material can convert electromagnetic energy to
heat. Materials that do not absorb microwaves and convert them to heat are considered
"transparent" to microwaves.) A review of the data from these experiments indicates that if either
the adsorbent or the solvent has a high dielectric loss factor, then microwave regeneration can
generally be used. The experiments also demonstrated that microwave regeneration is generally
not subject to heat and mass transfer. The following conclusions were also reached:
Volumetric heating minimizes thermal gradients
Mass transfer of VOCs out of the adsorbent is enhanced by a significant pressure-driven flow
("expulsion")
The vacuum minimizes external film resistance to mass transfer
No nitrogen counter-diffusion occurs.
Process Design Studies
During the process design studies, UT at Austin also examined the following parameters from an
econornicfeasibility standpoint: 1) adsorbent selection; 2) desorption thermodynamics, desorption
kinetics, and capital and operating costs (e.g., make-up inert cost, microwave power requirements,
and refrigeration/vacuum power requirements) for vacuum and gas purge systems; 3) system
configuration; and 4) microwave applicator configuration. The following conclusions were
reached:
Adsorbent Selection -Although the cost per pound for polymeric resins may often be much higher
than lower cost alternatives, the cost per pound of VOC treated was lower. In fact, recovery costs
increased as follows: polymeric resins (lowest), high silica zeolite, activated carbon, and MS 13X
(highest).
Vacuum Versus Gas Purge - Vacuum purge systems cost less ($0.206 per pound of VOC) than
gas (inert) purge systems ($0.271 per pound of VOC). Vacuum heating also has some attractive
features for fixed bed systems.
System Configuration - In general, somewhat unconventional configurations (e.g., axial flow
columns and horizontal rectangular bed columns) are suitable for microwave regeneration, in part
due to penetration depth limitations and other microwave-related issues.
Microwave Applicator Configuration - Configurations were investigated for both fluidized bed
systems (to replace steam or electronically heated units) and moving bed applications. Of the two
recommended for moving bed applications, the resonant cavity applicator is more sophisticated
and more efficient than the multimode applicator, which is essentially a microwave oven with
piping. _
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Comparative Economic Feasibility Studies
Comparative economic feasibility studies of various incineration technologies (i.e., thermal
oxidation, catalytic oxidation, regenerative thermal oxidation, rotary concentrated oxidation, and
fluidized bed oxidation) and solvent recovery technologies (i.e., fluidized bed adsorption recovery,
fluidized bed microwave regeneration, fixed bed stream regeneration, fixed bed hot gas
regeneration, and fixed-bed microwave regeneration) indicate that the solvent recovery
technologies are fairly competitive without even accounting for the cost of the recovered material.
Additionally, among the recovery technologies examined, fixed bed microwave regeneration was
the least expensive for the specific case studied ($0.099 per pound of VOC removed for a
counter-current stream with a VOC concentration of 3,220 ppm and a flow of 22,500 cubic feet
per minute or cfm).
Lab Pilot Column and Field Demonstrations
UT at Austin plans to use the following configurations for the proposed lab pilot and field
demonstrations:
Pilot Desorption Column
Multimode microwave applicator
Column: 6" glass process pipe
100 to 200 pound-mole per hour adsorbent throughput
25 pound-mole per hour recovered solvent
3 to 5. kilowatt (kW) microwave heating rate
Field Test Unit
Fluidized bed adsorber/steam regeneration system from EC&C, Inc.
Retrofit with compact microwave desorber unit
1.5 kW microwave generator
Rated stream flow of 70 cfm
Planned field test at a 3M site in Austin, Texas.
During these tests, UT at Austin plans to collect information on the validity of the process
simulation models, uniformity of heating, uniformity and depth of regeneration, purity of the
recovered solvent, adsorbent behavior, and controllability.
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Removal and Recovery of Volatile Organic Compounds for Gas
Streams
Presented on September 16, 1998 by Hans Wijmans, Membrane Technology
and Research, Inc.
MTR was founded in 1983 and was dedicated to the commercialization of membrane-based
separation technologies. MTR develops novel technologies based on innovative research and
development (R&D) funded largely through U.S. government contracts.
In 1995, 27.7 million tons of VOCswere emitted in the United States: 13 million tons from
industrial processes, 8.5 million tons from transportation activities, 0.7 million tons from fuel
combustion, and 0.5 million tons from other sources. Of the 13 million tons of VOCs emitted by
industrial processes, 3.8 million tons were produced by the chemical, petrochemical, and
pharmaceutical industries and 3.2 million tons were produced by coating and degreasing
operations. In order to control these emission, a number of VOC control technologies, including
the VaporSep process, have been developed.
The VaporSep technology separates and recovers VOCs from air or nitrogen. The first system
was installed in 1992 and there are currently over 50 systems in operation. The major application
of the VaporSep system is for monomer recovery in polymer production operations: poly vinyl
chloride (PVC), polyethylene, and polypropylene.
The VaporSep technology consists of a multilayer membrane composed of a selective layer, a
microporous layer, and a support web. The membrane is rolled around a collection pipe to form
a spiral-wound module. During treatment, the process stream (e.g., hydrocarbon in nitrogen) is
passed through a compressor and a condenser before entering the membrane. The compressor
removes the majority of the contamination (e.g., hydrocarbon) in the process stream; this material
exits the compressor in liquid form. A diluted process stream is then forwarded to the membrane
where the majority of the remaining contaminants are removed by the selectively permeable
membrane and concentrated in a permeate (hydrocarbon enriched). The treated air is exhausted
from the membrane through a vent and the permeate is forwarded to the condenser, where it is
combined with incoming process air. One of the advantages of this approach is that the
concentration does not depend on condenser pressure; therefore, high pressures and/or low
temperatures are not needed.
The system's performance at a PVC manufacturing plant highlights the material and costs savings
that can be obtained with the VaporSep process. This company typically lost 700,000 pounds of
vinyl chloride monomer (VCM) per year in its PVC reactor purge gas, losing usable VCM and
creating a need for emission controls. By forwarding the purge gas through the VaporSep
process, this company was able to reduce the amount of VCM forwarded to the incinerator by over
95%. The recovered VCM was then recycled for in-plant reuse, resulting in a significant cost
savings. The recoveries experienced at this plant concur with results obtained during vinyl
chloride recovery tests at eight different plants, during which the VaporSep Process yielded an
average- psrc.enLrecov.ecy_Ql.93.%,._Capital cosjts.,at.the.ejghtjDjantsj^ngLellrqrrL$50,pOO to
$250,000 and annual savings ranged from $85,000 to $900,000.
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The VaporSep process was first installed for monomer recovery in polyolefin production in 1996
in the Netherlands. Since then, 15 additional systems have been ordered and the process
received the 34th Kirkpatrick Chemical Engineering Achievement Award in 1997. During polyolefin
production, a monomer supply and other raw materials are processed through a polymerization
reactor, followed by resin degassing where nitrogen is added. In the past, off-gases from the resin
degassing step were sent to a flare where recoverable nitrogen and monomer were lost. By
sending the off-gas through the membrane system, however, the recovered nitrogen and
monomer (C,, C3, and C,) can be recycled (in-process) for reuse. A benefits analysis of the plant
showed a net payback in less than 2 years. This conclusion was based on the following costs and
savings: $1,500,000 for installation; $300,000 per year for operation; and $1,100,000 per year
from recovered propylene.
A comparison of the VaporSep and other membrane systems with condensation and adsorption
(using both steam regeneration and off-site regeneration) indicates that: 1) unlike their
competitors, membranes are able to treat moderate to very high concentrations (0.1 to 99% VOC
streams) at low to moderate flow rates (from 1 to 10,000 scfm); and 2) that membranes lose their
competitive advantage when treating very high flow rates or low concentration streams.
In closing, since 1992, systems have been installed with a total capacity to remove over 30,000
tons of VOC per year and save over 3 trillion BTUs per year of energy. Given the number of
systems currently in design and under construction, these values are expected to increase to over
50,000 tons per year and over 5 trillion BTUs per year in 1999.
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Synthetic Adsorbents in Liquid Phase and Vapor Phase
Applications
Presented on September 16,1998 by Steven Billingsley, Ameripure, Inc.
This presentation gives an overview of synthetic resins, some typical system flow schematics, and
technology applications for both liquid and vapor phases.
Advantages of Synthetic Adsorption Resins
Synthetic resins are engineered compounds with large surface areas, high adsorptive capacities,
physical integrity, and fast adsorption/desorption kinetics. They also have no capacity loss from
repeated regenerations and support very little catalytic activity, making them suitable for alcohol
recovery. They can be used to adsorb aliphatic and aromatic hydrocarbons, chlorinated
hydrocarbons, aldehydes and ketones, alcohols and acetates, pesticides and herbicides, chemical
agents, and siloxanes.
Liquid Phase Regenerative Adsorption Systems
During liquid phase treatment using a regenerative adsorption system containing synthetic resins
(e.g., carbonaceous or polymeric), process water enters the packed beds after being pre-filtered
to remove excess particulate. As the process water flows up the bed, contaminants are adsorbed
on the synthetic resins contained within, before exiting the unit for discharge. After the bed has
become saturated with organics, it is regenerated using countercurrent steam. During steam
regeneration, the steam proceeds down the bed and exits through the bottom of the bed. The
recovered material is cooled and sent to a phase separation tank, where the recovered organic
is forwarded for recycle and the aqueous phase is forwarded back through the resin beds.
Typically, these systems can be applied to landfill leachate, for groundwater remediation, for
wastewater treatment, and for resource recovery.
Vapor Phase Regenerative Adsorption Systems
During vapor phase treatment using synthetic resins (e.g., polymeric), two types of adsorbent bed
designs are typically used: packed bed systems (for flows less than 500 scfm) and fluid bed
systems (for flows greater than 500 scfm). During treatment, contaminants are removed from the
process air as it flows up through the adsorbent. After the bed has become saturated with
organics, it can be regenerated using microwave energy. During the microwave regeneration, an
inert gas such as nitrogen is forwarded through the bed as it is heated using microwave energy.
The desorbed contaminants exit the bed with nitrogen gas and proceed to a condenser, where
the organics are recovered for reuse. Typically, these systems can be applied to landfill gas
clean-up, soil vapor extraction, solvent recovery, vapor recovery, and industrial off-gas. If used to
recover high-value solvents, the cost of recovered material can defray initial capital costs.
Furthermore, in addition to being very efficient, microwave regeneration offers the following
advantages over other regeneration systems: it creates no chemical or catalytic waste; recovered
products have low water content; it is energy-efficient; it heats uniformly and has reduced
regeneration times; and operating costs are low.
Study Hesults
The following pilot, treatability, and field study results were presented to demonstrate synthetic
adsorbent performance at different facilities and using different configurations.
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Pilot Testing and Proof of Principle Demonstration - Pilot testing took place at a refinery site with
an influent concentration of 140 to160 parts per billion (ppb) methyl tertiary butyl ether. In addition
to methyl tertiary butyl ether, other gasoline components were present in the process stream.
During the test, 1,250 gallons were treated at a rate of 0.5 gpm. The concentration of organics in
the effluent from the synthetic resin (i.e., L-493) was non-detectable by U.S. EPA "Test Methods
for Evaluating Solid Waste," SW-846, Method 8240. Steam regeneration produced less than 5
gallons of condensate, with a concentration of 38.7 ppm methyl tertiary butyl ether.
Treatabilitv Study: Pilot Demonstration - Combined liquid- and vapor-phase adsorption was used
during a pilot demonstration at a US Army groundwater site with an influent contaminated with
1,500 to 2,500 ppb of various halogenated aliphatics (e.g., 1,1,2,2-tetrachloroethane;
trichloroethylene; vinyl chloride). During the study, approximately 200,000 gallons were treated
at a rate of 10 gpm. The concentration of contaminants in the effluent was non-detectable using
EPA SW-846 Method 624. Steam regeneration produced 80 gallons of condensate. Utility costs
for the system were $0.08 per 1,000 gallons and total O&M costs were $0.74 per 1,000 gallons.
Vinyl chloride and 1,1,2,2-tetrachloroethane breakthrough started to occur at 6,000 and 7,000 bed
volumes, respectively, and the desorption cycle lasted approximately 350 minutes.
Field Scale System: Service Station - A fixed bed vapor adsorption system was used to separate
BTEX and other aliphatic hydrocarbons from a soil vapor recovery system (250 scfm) installed at
a service station. Approximately 4.8 gallons of contaminants were recovered per day. The
recovered product (7% water by volume) was desiccated and delivered to the customer's low-
grade fuel tank for resale. Utility costs for the system were $0.15 per pound of recovered
hydrocarbon.
Field Scale System: Chemical Process Plant - A fixed bed vapor adsorption system is currently
in the start-up phase to treat a 250 scfm stream at a chemical process plant. Ameripure estimates
.that up to 6 pounds of hexamethyldisiloxane, trimethylsiloxanol, benzene, and toluene will be
recovered per hour using this system. The project is in the data acquisition phase.
Conclusions
As demonstrated by Ameripure and other companies' results, synthetic resins offer an excellent
means of VOC recovery due to their high capacities and rapid kinetics. Lab-scale, pilot-scale, and
full-scale data confirm the technical viability and cost effectiveness of these systems.
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Cryogenic Condensation for VOC Control and Recovery
Presented on September 16, 1998 by Robert Zeiss, BOC Gases
This presentation gives an overview of cryogenic condensation and offers a case study
highlighting the advantages of the Kryoclean system.
Cryogenic Condensation
Cryogenic condensation is an extension of typical condensation which uses lower temperature
refrigerants to reduce system temperatures. Unlike traditional nitrogen gas condensation systems,
the Kryoclean VOC control system functions as a vaporizer and utilizes the cooling value of the
liquid nitrogen to provide cooling during abatement. The flexibility of the Kryoclean VOC control
system gives it the ability to handle increased loads at a high level of compliance, without the need
for additional add-on equipment. This is accomplished by lowering the temperature when an
increased load needs to be processed. Commercial test results using methylene chloride streams
and an average nitrogen flow and inlet solvent load of 20.4 scfm and 20.3 Ibs/hr, respectively,
yield an average VOC recovery efficiency of 99.43%, and an average outlet temperature of
-91.33ฐF. Additionally, preliminary outlet emission test results indicate that emissions went from
approximately 210 ppmv at - 88ฐC to 7 ppmv at - 109ฐC.
Case Study
A specialty chemical manufacturing company needed to control VOC emissions from storage
tanks, including acetone, methanol, heptane, ethyl acetate, and acetic acid. The company hired
an environmental consultant to evaluate VOC control technologies on both a technical and an
economic basis. The following technologies were evaluated: thermal oxidizer, catalytic oxidizer,
flare, carbon adsorption, scrubber, and cryogenic condensation. EPA OAQPS cost estimation
techniques were used to evaluate the different technologies. The following capital and installation
costs were accounted for: primary control device cost, auxiliary equipment, instrumentation,
freight, foundation supports, handling and erection, electrical, piping, insulation and painting. The
following operating costs were also accounted for: operator costs (based on labor rates), utility
costs of consumables, interest, control system life, taxes, insurance, and administration.
Based on this evaluation, the environmental consultant determined that cryogenic condensation
had the lowest annual operating costs of all the technologies evaluated (e.g., from $65,000 to
$445,000 less per year than the other alternatives). Capital costs, which were only $156,000 less
than the least expensive alternative (from a capital cost perspective), were also less than three
of the other technologies studied.
Conclusions
Field study results indicating 99.6% recovery at -94ฐF and laboratory test results showing treated
concentrations of less than 10 ppmv at -164ฐF demonstrate the technical potential of the
Kryoclean system. These results, combined with the system's flexibility, low operating costs
(which can be attributed to the reuse of the vented nitrogen for blanketing or inerting), and low
mist/fog formulation (due to controlled surface temperatures), make the technology an attractive
option for VOC control. There is also the potential that, in the future, cryogenic condensation
systems could be used to cool VOC-laden streams to -250ฐF.
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Brayton Cycle Systems for Solvent Recovery
Presented on September 16,1998 by Joseph Enneking, NUCON International,
Inc.
The Brayton Cycle Process is a low temperature condensing technology used to recover solvents
for reuse. The technology, which is based on the Brayton thermodynamic cycle, was developed
and patented by 3M in the mid-1980s and licensed to NUCON International Inc.
During treatment, process gas is transferred from a turbo-compressor to a recuperator (e.g., heat
exchanger), where the air is cooled. The cooled air is then forwarded to an expander, where
isentropic expansion results in a large temperature drop. The chilled gas is then forwarded to the
recuperator, where it is used to cool gas entering the recuperator. The condensed solvent is
separated in vertical cylindrical vessels fitted with mist eliminators. The pressure change
responsible for the isentropic expansion of the gas can be developed by a compressor at the inlet
side of the process or a vacuum on the outlet side.
The basic process can be applied in a wide variety of solvent recovery or pollution control
applications. However, different process air characteristics (e.g., solvent types, concentrations,
and flow rates) along with different emission control requirements have resulted in a variety of
equipment configurations. When the concentration is below 5,000 ppmv, a concentrator is
needed for the condensation process to be effective.
Case Study #1: Tape Coating Process, Greenville, South Carolina
During this project, the Brayton Cycle Process was used to treat a low concentration (2,500 ppm
of heptane), high flow (7,000 scfm) stream. During treatment, the process air was forwarded
through a filter before entering two activated carbon beds prior to being exhausted to the
environment. When a bed became saturated with hydrocarbon, it was taken off-line for
regeneration. During regeneration, inert nitrogen gas was processed through the beds to desorb
the contaminant (e.g., heptane). After exiting the beds, this gas was forwarded through the
Brayton Cycle Process. The regeneration air was forwarded through an expander, where it was
cooled. The condensed solvent was separated for reuse (at a temperature of -20ฐF and
atmospheric pressure) and the lean gas was then forwarded through a compressor, where it was
heated before being recirculated through the carbon beds. The same closed loop process was
used to cool the bed before it was returned to the adsorption mode. The use of two beds in the
system permits continuous operation.
The residual amount of solvent on the bed at the end of the heating cycle was less than 5% while
the capacity of the carbon bed to hold solvent during the adsorption cycle was over 25%. The
process achieved over 95% recovery of the heptane, which was then recycled to the
manufacturing plant. The capital cost of the system was $1.64 million. Since the equipment
operates automatically, little or no operator supervision was required.
Case Study #2: Tablet Coating Process, Pfizer, Puerto Rico
During this project, a medium concentration (10,000 ppm of methylene chloride and methane), low
flow (1,700 scfm) stream was treated. During treatment, the process air (100ฐF) was cooled and
then forwarded through the turbo-compressor and an after-cooler. Any condensed water was tnen
separated and the process air was forwarded through a desiccating dryer bed to prevent freeze-up
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in the low temperature sections of the process. After exiting the desiccator, the process air was
forwarded through the recuperator, where it was cooled. After separating the condensed solvent,
the process air [-70ฐF and 23 pounds per square inch area (psia)] was forwarded to the turbo
expander, where it was cooled to less than -150ฐF (6.5 psia). After passing through the
recuperator, the process air was forwarded through the vacuum pump (+230ฐF) and back to the
process.
Over 90% of the air was recycled back to the process. The overall efficiency of the process was
98%. The capital cost of the system was $1 million. Since the equipment operates automatically,
little or no operator supervision was required.
Case Study #3: Medical Product Manufacturing, Carter Wallace, Indirect BRAYCYCLEฎ
System
The Braycycleฎ Process was used at this site to treat a high concentration (100,000 ppm of
tetrahydrofuran), low flow (500 scfm) stream. Since cooling and condensing could not be supplied
by the process stream, an indirect Brayton cycle system was used that consisted of separate
process air and Brayton cycle loops. The high pressure version of the Brayton cycle process was
chosen to reduce the size of the equipment.
During treatment, process air was forwarded through a pair of recuperators, followed by a pair of
separators where the condensed solvent was removed. After passing through the second
recuperator (#2), the process air was re-routed through the original recuperator (#1) and then a
blower before being exhausted. In addition to the "process gas loop", a separate "Brayton cycle
cooling loop" consisting of the following elements (in order) was used: recuperator #1a, pre-
compressor, turbo compressor, heat exchanger (for process heat), cooler, recuperator (#1a),
expander, and recuperator (#2). (Note: The second recuperator, #2, was shared with the process
gas loop.) Dehumidification was not needed because the gas stream in the Brayton cycle cooling
loop was composed of dry nitrogen. The solvent volume was reduced to 0.05% by volume. The
overall removal efficiency of the process was 99%. The capital cost of the system was $1 million.
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Control of VOCs in Refinery Wastewater
Presented on September 17,1998 by Mike Worrallof AMCEC Inc.
This presentation briefly discusses aromatics and their regulation in wastewater. Numerous
control technologies are broadly discussed before a more detailed discussion of AMCEC's
Benzene Removal Unit (BRU) is provided, complete with a case study.
Aromatics and their Regulation in the Refinery Industry
Aromatic hydrocarbons, which are present in petroleum, are a wastewater problem for the refinery
industry. Many aromatics are partially soluble in water, as demonstrated by the following
solubilities: benzene -1800 parts per million by weight (ppmw); toluene - 470 ppmw; ethyl
benzene -150 ppmw; and xylene -150 ppmw. (Note: These solubilities are measured when the
organics are present in water and there is not an excess of oil or hydrocarbon fluids.) These
contaminants enter the wastewater during various process steps and activities.
A typical refinery discharges between 100 to 2,000 gpm of wastewater. Under the National
Emission Standards for Hazardous Air Pollutants (NESHAPs), any refinery emitting over 10 metric
tons per year of HAPs must control its wastewater concentrations to less than 1 ppmv, with at
least 98% captured/destroyed. Since many refineries are very large, and their wastewater
facilities can be located a distance from the source (e.g., up to 2 miles), this can create serious
processing difficulties.
Refinery wastewater is typically produced by the desalter (which removes corrosive salts from the
oil with hot water flushes), aromatic units, chemical units (which frequently leak), and the general
process area (from leaks, spills, and drainage). In general the desalter is the major source for
contaminated process wastewater and is typically the largest contributor to total benzene, toluene,
ethylene, and xylene (BTEX) discharges. Since NESHAPs does not permit open process drains,
where possible the HAP treatment unit is located adjacent to the HAP source since enclosed
drainage systems are often very expensive.
To highlight the wide-scale applicability of this problem, the yearly wastewater discharge from a
"typical" refinery (e.g., with a flow rate of 100 to 2,000 gpm and contaminant concentrations of 50
ppmw of benzene and 50 ppmw of toluene, ethylene, and xylene) was calculated. Assuming an
average flow of 500 gpm and an average concentration of 50 ppm benzene, approximately 54
metric tons of hydrocarbons (e.g., benzene) would be released per year, well over the 10 metric
tons per year limit.
Control Technologies
There are several techniques/technologies available to prevent or control HAPs and VOCs in
wastewater discharges. Some of the advantages and disadvantages of these
techniques/technologies are described below:
Desalter Emulsion Breaker - Although this technology has low capital and operating costs, its
impact is limited. For example, if aromatics originated from sources other than the desalters, this
technology would not be effective.
Activated Carbon - Liquid Phase - This method has a low capital cost but a very high operating
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cost. The high operating cost is not only due to fuel costs to run the kiln, but also to high
transportation costs associated with transporting the carbon for reactivation in a high temperature
kiln which could be 500 miles away. For a recent 500 gpm project, capital costs ranged from
$0.25 to $0.50 million and operating costs ran from $1.2 to $1.5 million.
Steam-Stripping - Although this method is very effective, it has a high capital cost and a high
operating cost due to use of extreme temperatures. In addition, these systems are easily fouled
with other contaminants.
Air-Stripping-This technology has only moderate capital costs but high operating costs associated
with carbon reactivation. Also, this process can easily foul the wastewater with biological slime
created from oxygen exposure. Potentially explosive conditions in the stripper may also be a
safety concern.
AMCEC's BRU
AMCEC's BRU nitrogen stripping procedure performs vapor-phase carbon adsorption with in situ
regeneration. In addition to being safer and less likely to foul than air stripping (since there is no
oxygen present), the carbon in the BRU does not require expensive transportation to a high
temperature kiln for regeneration. Instead, regeneration takes place on site using a closed loop
nitrogen process.
When used to treat a refinery wastewater with a flow rate of 500 gpm and concentrations of 50
ppm for benzene and 50 ppm for toluene, ethyl benzene, and xylene, the process required 1500
Ibs/hr steam, 50 kilowatt per hour electric power (which did not include power for the wastewater
pumps), 300 standard cubic feet per hour nitrogen, and an equipment cost of $1,250,000. When
the hydrogen sulfide load is more than a few ppm, the hydrogen sulfide will load up on activated
carbon. Although this is a concern, since the system has very little oxygen, it is not a huge
problem.
There are currently 12 BRU systems operating at various refineries. This units are currently
treating flows ranging from 100 to 3,000 gpm. These systems have proven to be effective and
reliable (e.g., wastewater streams with BTEX concentrations of 1,000 ppmw are typically reduced
to concentrations of less than 0.5 ppmw). Additionally, since BRUs are recovery systems, they
do not get the HAPs attention that wastewater treatment requires.
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Separation of Volatile Organic Compounds from Water by
Pervaporation
Presented on September 17, 1998 by Richard Baker, Membrane Technology
and Research, Inc.
This presentation discusses what pervaporation is, its effectiveness, how it can be applied, and
when it is most useful.
The Pervaporation Process
During pervaporation, contaminants are transferred from a liquid feed stream (e.g., 500 ppm
toluene in water) through a selective membrane to an inert vapor stream. The purified air (e.g.,
less than 1 ppm toluene) is exhausted and the permeate (e.g., toluene and water vapor) is
forwarded to a condenser, where it is cooled to liquid form (e.g., 5 to 10% toluene). The success
of this process is based on the fact that the membrane is much more permeable to the
contaminant (e.g., toluene) than water.
A comparison of feed velocities to separation factors (i.e., the measure of the selectivity of a
membrane as a function of feed velocity) indicates the applicability of pervaporation for VOC
separation. The comparison also shows that hydrophobic compounds such as trichloroethylene
and toluene are better candidates for pervaporation than their more hydrophilic counterparts (e.g.,
ethyl acetate or 1-propanol). This is because the more hydrophobic a compound is, the greater
is the separation factor. Unfortunately, a stagnant solution layer often forms next to the
membrane which depletes the organic component by up to 90%. The feed velocity can be
increased to reduce the stagnant layer; however, depletion is still a factor.
Once-Through Pervaporation
During processing using a "once-through pervaporation" system, the liquid stream is forwarded
from a feed pump and heater, where it is heated to 150ฐF, and then through the membrane
modules. The treated water is forwarded for discharge and the permeate is cooled in a condenser
responsible for creating the vacuum used to drive the entire process. These systems can be used
to separate isopropanol because membrane performance is independent of the feed rate.
Batch Pervaporation
During batch pervaporation, a surge tank is used to contain the feed solution until there is enough
to start the system, which is about 50 to 100 gallons. During processing, the feed is transferred
from the surge tank, through a filter to the feed/process tank. The feed is then recirculated
through feed pump, heater, and membrane modules until treatment is completed. After treatment
is completed, the treated water is drained from the feed/process tank. Permeate from the
membrane modules is cooled in the condenser and collected for discharge from the system. The
entire system is controlled by a simple PLC.
A comparison of percent toluene remaining in the feed over time for three batch runs shows that
the first run was a little slower at 110 minutes than the last two runs, which took less than 90
minutes. The last two runs had an average treating rate of 0.5 gpm.
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Applications
As described below, pervaporation is being used in the food and flavor industry, for fine
chemicals/process streams (e.g., Pharmaceuticals), and for pollution control, including
groundwater and industrial wastewater. Examples of these applications are included below.
Food and Flavor Industry - In an application in which permeation was used to treat a
peppermint oil decanter run-off, the permeate was diluted 20-fold. Since peppermint oil is
very valuable, the use of pervaporation was driven completely by the value of the recovered
product.
Pollution Control - Pervaporation was used to remediate groundwater contaminated with 800
ppm methylene chloride. During treatment, the concentration methylene chloride in the
groundwater was reduced to less than 3 ppm in under 2 hours. The resulting permeate had
a concentration of 800,000 ppm. Unfortunately the groundwater contained iron which built
up and fouled the system. Treatment was discontinued as a result.
Fine Chemicals/Process Streams - Pervaporation was used to reduce wastewater
concentrations in a 300 gallon per day flow. During treatment, concentrations were reduced
from 30 ppm methylene chloride to 35 ppb methylene chloride, which qualified the
wastewater for discharge. Prior to the installation of the pervaporation system, the company
was trucking the water for disposal off-site at $0.34 per gallon.
Ideally pervaporation should be used to treat small volume streams such as those in the flavor
production industry with moderate concentrations of contaminants. Distillation or incineration
should be used to treat very concentrated streams (greater than 5%), and air stripping or carbon
adsorption is much more economical for the treatment of low concentration streams (less than
100 ppm).
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Dehydration and VOC Separation by Pervaporation for
Remediation Fluid Recycling
Presented on September 17, 1998 by Leland Vane, U.S. EPA NRMRL
This presentation provides a brief background discussion of pervaporation and dehydration
followed by a pilot-scale study highlighting soil remediation successes and a description of current
EPA pervaporation efforts.
Background of Pervaporation and Dehydration
Pervaporation combines permeation and evaporation to remove organic contaminants from liquid
streams. During treatment, organic contaminants pass from a contaminated liquid phase through
a hydrophobic, VOC-selective membrane to an inert vapor phase which is under vacuum. When
used as a dehydration system, alcohol and water in a liquid phase is pushed under pressure
through a water-selective membrane to the vapor phase. Dehydration systems are more
frequently used in industry, especially in Europe.
During soil remediation at DOE and DOD sites, a flushing solution containing VOC-solubilizing
agents is pumped through an injection well to an aquifer contaminated with non-aqueous phase
liquids (NAPLs). The solubilized light non-aqueous phase liquids (LNAPLs) and flushing solution
are extracted from the subsurface through a withdrawal well. Economics dictate that the
surfactant then be recovered for reuse.
Current soil flushing options include aqueous surfactant solutions for solubilization, mobilization,
and foam flood, and pure solvents for pure alcohols, mixed alcohols, and alcohol and water.
Mixed surfactants and alcohols are also an option.
Pilot Demonstration at Hill Air Force Base
A pilot demonstration was performed at Hill Air Force Base near Ogden, Utah, which at one point
was contaminated with 100,000 to 1,000,000 gallons of chlorinated solvents. Currently this site
is contaminated with 50,000 gallons of chlorinated solvents.
During treatment, injectate was added to the subsurface at a rate of 6 gpm. The injectate
contained 8% by weight surfactant, 4% by weight isopropyl alcohol (IPA), and 1% by weight
sodium chloride to control the surfactant properties. The injectate was mixed in a tank prior to
injection into the contamination plume. The surfactant was extracted, along with recovered NAPL
(e.g., VOCs) and groundwater, through a withdrawal well at a rate of 11 gpm. The extracted fluid
contained 4% by weight surfactant, 2% by weight IPA, and 5,000 milligrams per liter (mg/L) VOC
(trichloroethylene, trichloroethane, and tetrachloroethene). This fluid was forwarded to a
pervaporation unit, where the NAPL and IPA were removed. The diluted surfactant solution was
then forwarded to an ultrafiltration unit where water and residual IPA were removed before
returning the recovered surfactant to the mixing tank.
Since the injectate had a solubilization capacity of 200,000 to 500,000 ppm, the source could
theoretically be cleaned up in a matter of years rather than the decades needed if pump-and-treat
was being used. Additionally, since approximately 89% of the surfactantwas recovered for reuse,
over $4,700 was saved each day (i.e., 81% of the surfactant cost without recycling). This is a
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major benefit since most sites want to limit remediation costs.
If the injectate contained higher alcohol concentrations, alcohol recovery may be warranted. For
example, if the injectate contained 4% by weight IPA, over 2,880 pounds of IPA would be injected
per day. This corresponds to a material cost of approximately $1,150 per day or almost $400,000
per year.
Alcohol Recovery and Dehydration
Pervaporation was not originally intended for alcohol treatment. However, necessity dictated its
use for this purpose. During dense non-aqueous phase liquid (DNAPL) separation and alcohol
recovery, a two-step pervaporation process can be used. During the first pervaporation step,
DNAPL is removed and the aqueous stream (surfactant, alcohol, and water) is forwarded to an
ultrafiltration unit where the alcohol and water are removed and the surfactant is recovered for
reuse. The alcohol and water are then forwarded to a second pervaporation unit, where the
recovered alcohol is forwarded for reuse and the water is processed for treatment/discharge. If
warranted, the DNAPL could be removed using an alternate process, such as steam-stripping, and
the alcohol and water could then be separated using pervaporation. Additionally, if surfactant is
not present in the aqueous stream (e.g., an alcohol flushing stream consisting of NAPL, water,
and alcohol), the ultrafiltration step can be eliminated from the process.
Technical Approach/Current Status
EPA is currently concentrating on bench-scale and pilot-scale experiments with surrogate
solutions. Bench-scale studies are typically used for process modeling and pilot-scale
demonstrations are performed with actual remediation fluids. To date, the EPA has performed
bench-scale experiments on two surfactants: Triton X-100 (nonionic) and sodium dodecyl sulfate
(anionic). Pilot-scale tests have been performed on DowFax 8390 (an anionic surfactant
composed of hexadecyl diphenyl oxide disulfonate) and Coptic Aerosol MA 80 (an anionic
surfactant composed of sodium diehexyl sulfosuccinate with IPA and sodium chloride as
modifiers). Pilot-scale demonstrations have shown that performance degrades slightly with the
addition of surfactant. This was determined based on trichloroethane and toluene percent
removals; however, this is not a major problem and can be accounted for during system planning.
EPA is currently designing and constructing a field pervaporation unit to treat a
tetrachloroethene/surfactant stream at Camp LeJeune AFB; treatment should start in January
1999. EPA is also considering IPA recovery at the same AFB. Technical personnel are also trying
to relate Henry's Law constants to surfactant properties and concentrations. EPA is also
attempting to model the effect of micelles on mass transport in pervaporation.
Conclusions
In situ soil-flushing can result in reductions in both remediation times and remediation
expenditures. Surfactant and IPA recycling with pervaporation can also lead to significant material
and cost savings. In fact, a 10-gpm installation can expect to save more than $1,000,000 per year
by using surfactant and IPA recycling. Based on this information, it can be concluded that VOC
separation and recovery are critical to cost-effective in situ soil flushing. Additionally,
pervaporation can be used to separate VOCs from the following streams: VOC-NAPL/surfactant
solutions, alcohol/water solutions, and water/alcohol solutions.
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Polymeric Resins for VOC Removal from Aqueous Systems
Presented on September 17,1998 by Yoram Cohen, University of California
(UCLA), Los Angeles
UCLA's industrial affiliates questioned whether polymeric resins can be regenerated and whether
they merit consideration if they cannot withstand multi-cycle use. Polymeric resins were initially
used in chemical analyses as a means for concentrating a specific chemical in a sample. As early
as the mid-1960s, research was done on the application of ion exchange resins for the removal
of organics from aqueous streams. Commercial polymeric resin applications date back to the
early- to mid-1970s. With new resins, not only adsorption but also absorption is important,
opening the door for other types of applications.
A 1979 paper from Chemical Engineering Progress showed the adsorption of a mixture of
chlorinated pesticides in a packed bed. In this article, activated carbon was compared to XAD-4
(a polystyrene resin produced by Rohm and Haas). XAD-4 exhibited very low leakage compared
to the activated carbon, and this provided motivation for continued research.
The main questions that were addressed included:
Are the surface area and pore size distribution suitable for VOCs?
Can solute-polymer affinity be controlled?
Can polymeric resins be readily regenerated?
Are polymeric resins stable for cyclic operation?
Are there severe mass transfer limitations?
When discussing the pore size and volume distribution of polymeric resin, the available volume,
rather than the actual pore size/volume, needs to be addressed. Inaccessible pore volume may
range from 5 to 30%. When dealing with hydrophobic resins, the loss in accessible pore volume
due to wetting becomes a very important issue. The manner in which resins are pretreated will
determine what percentage of the resin's volume will be accessible. It is important to note that the
accessible volume of some polymeric resins can increase with continued use. This improvement
in performance can be attributed to resin swelling. It can also indicate that pretreatment was not
complete.
Some newer resins have a surface area which is comparable to that of activated carbon. Before
1990, resins were made with free-radical polymerization; after 1990 resins were made using the
Friedel-Crafts reaction. Resins made using the Friedel-Crafts reaction have much smaller cross-
linking distances between chains and a higher degree of cross-linking, resulting in much larger
surface areas. In addition to the smaller pore sizes, many newer resins are no longer macro-
porous. With these changes, mass transfer limitations may need to be studied in more detail in
the future. Moreover, resin pretreatment is important in determining the working adsorption
capacity of the resin. Pretreatment often involves the use of a water-soluble aliphatic alcohol
(e.g., methanol) to displace air or wet the resin, then water to displace the solvent.
Because a polymeric resin is made with few functional groups (often it is the single dominant
functional group which gives the surface its adsorption characteristics), one can ascertain the
affinity (e.g., Hanson solubility parameter) and predict the adsorption capacity based on
thermodynamics. Various studies have shown that adsorption capacities of a variety of solutes
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and polymeric resins can be correlated with solubility parameters. Such an approach is not
feasible with activated carbon, which has more functional groups.
Affinity can be evaluated by testing whether the adsorption capacity varies (i.e., whether it scales)
with surface area. Trichloroethylene adsorption capacities over six orders of magnitude of
concentration were plotted against adsorption capacities over five orders of magnitude. A good
correlation was observed for five resins, indicating that the adsorption capacity scales with surface
area for the five hydrophobic resins in question. Activated carbon results plotted on the same
graph indicated that activated carbon had a higher adsorption capacity than the five resins.
Affinity can also be evaluated by recognizing that fugacity is the driving force for adsorption. As
an example of the approach, adsorption onto XAD-4 resin of phenol and a number of hydrophobic
chlorinated solvents (tetrachloroethene, trichloroethene, chloroform, and methylene chloride) was
plotted versus the solute fugacity (concentration multiplied by Henry's Law constant) in the solution
phase. XAD-4 exhibits an affinity for hydrophobic compounds, but a higher adsorption capacity
for phenol, which is slightly more polar. On activated carbon, chain formations or multiple layers
can be adsorbed. Polymeric resins adsorbed all of the compounds at concentrations up to their
respective solubility limits; at these high concentrations the capacity of some resins can approach
or even exceed that of activated carbon.
Methanol was selected for polymeric resin regeneration. Methanol is used to displace the water
and regenerate the column after breakthrough is experienced. In situ regeneration using methanol
occurs under very mild conditions. If required, highertemperatures or microwave regeneration can
be used. When chlorobenzene is treated with XUS resin (Dow), breakthrough occurs at about
1200 bed volumes. Regeneration with methanol takes about 15 bed volumes, resulting in a net
concentration factor of about 50. Economics dictate how long the regeneration step is run.
Plotting fractional recovery versus methanol bed volumes indicates that greater than 90% of the
chlorobenzene is recovered after about 10 bed volumes. After 15 bed volumes the recovery rates
of 95% are achieved. Equilibrium dictates that a very high volume of methanol is required to get
complete chlorobenzene recovery.
Benzoic acid was adsorbed on MN-170 resin. Breakthrough occurred at approximately 1000 bed
volumes (with 2500 bed volumes to saturate the resin). Benzoic acid was tested in part because
volatility problems in the laboratory could be avoided. A curve was plotted for methanol
regeneration of columns saturated with benzoic acid at different concentrations (100 to 400 mg/L).
Nearly complete regeneration occurred at around 40 bed volumes or less, resulting in a
concentration factor of approximately 25 to 50. Because methanol is soluble in water and water
is present in the column when regeneration begins, this relationship was of particular interest.
Adsorption (milligrams per gram) was plotted against concentration of methanol-water mixtures
(20%, 40%, 60%, 80%, and 100% methanol). Water and methanol adsorption capacities differed
by more than an order of magnitude. By using multiple regenerant passes, the concentration
factor was increased from 50 to 250. The number of regenerant passes utilized on-site will be
determined based on economics.
Solute recovery and solvent regeneration can be summarized as follows:
The solute is concentrated in the regenerating stream
Concentration factors range from 10 to 250
Solvent can be recycled up to 3 to 4 cycles
Solvent can be regenerated using appropriate separation methods.
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Resin stability was evaluated by examining the dynamic adsorption capacity over repeated
adsorption/regeneration cycles. The deviation of the above ratio from unity was within about +/-
2%. This difference can be attributed to either experimental error or to adsorption capacity
fluctuations related to: 1) multiple passes of water and methanol through the bed; and 2) the
degree to which methanol is removed after regeneration. Plots of up to 80 cycles with the XUS
resin showed no decrease in the stability or adsorption capacity of the resin.
The mass transfer limitations of benzoic acid were compared with literature data for three
adsorbents: activated carbon (Takeuchi and Suzuki, 1984), macroreticular adsorbent (Huang et
al., 1994), and macronet (this study). The reported intraparticle diffusivities for the three
adsorbents were: 0.41x10~11, 2.71 x1CT11, and 1.9 x10~11 square meter per second, respectively.
The mass transfer limitation of the newer resin was significantly less than the activated carbon.
However, the older macroreticular resin used by Huang et al. exhibited a somewhat lower degree
of mass transfer limitation, as expected for this higher pore size resin.
Table 3 summarizes the properties of activated carbon and polymer resins. When comparing the
properties of activated carbon to polymeric resins, the following issues need to be considered: 1)
the high heat of adsorption (requiring significant energy input) of the carbon; 2) the degradation
of carbon during repeated regeneration cycles; and 3) the relative cost.
Table 3. Polymer Resins Versus Activated Carbon
POLYMER RESINS
High surface area (greater than 1000 square
meters per gram or m2/g)
Low heat of adsorption (less than 4
kilocalories per mole or kcal/mole)
Solvent regeneration (e.g., using aliphatic
alcohols)
No loss in performance over many cycles
Limited choice and high cost (approximately
$20 per kilogram)
ACTIVATED CARBON
High surface area (greater than 1000 m2/g)
High heat of adsorption (greater than 10
kcal/mole)
Thermal regeneration (e.g., steam
regeneration)
5 to 10% degradation per cycle
Readily available, low cost (less than or
equal to $2 per kilogram), general adsorbent
material
Spent carbon may have to be treated as
hazardous waste
In summary:
Polymeric sorption resins can be regenerated in situ by solvent regeneration or thermal
recovery.
Cyclic adsorption/regeneration processes are feasible.
Solvent regeneration and solute recovery from the solvent may be the more expensive
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portion of the process.
The dominance of low-cost activated carbon is an important reason for the small market
share of polymeric resins and this in turn explains their high cost.
Capital costs for polymeric resin packed-beds should be similar to granular activated carbon
adsorption systems.
Operating costs for polymeric resin packed beds should be lower for the following reasons:
Virtually no resin attrition
Resin stability is maintained over many cycles
Regeneration can be performed in situ under mild conditions.
There is a need for design data (adsorption/regeneration) and a better understanding of
adsorption/regeneration coupled with polymeric resins.
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The New Clean Process Advisory System (CPAS)
Separation Technology and Pollution Prevention Information
Tool
Presented on September 17,1998 by Robert Patty, The Construction
Productivity Institute (CPI)
CPAS is a set of pollution prevention process and product design tools containing design
information regarding new and existing clean technologies and design for constructability. EPA
is concerned with constructability because of the micro-environment that exists on a project site
in which we throw some 5 to 8% of our workforce during the process of construction itself.
According to Cheremisinoff and Ferrante (1989), "The most significant technical barrier to waste
minimization may be a lack of suitable engineering information on source reduction and recycling
techniques." Although the situation has improved, designers lack a tool which provides pertinent
information as attested to by the following statement. "There is a large dearth of pertinent
information and guidance techniques to accomplish source reduction - design process changes.
For example, pollution prevention options for process effluent streams already installed by other
organizations, are not well documented." (U.S. Congress, Office of Technology Assessment,
1994).
According to Buckminster Fuller, "If you want to change a person's way of thinking, don't give
(him) a lecture, give (him) a tool." In this case, the required "tool" is an information system that can
easily be used to begin assimilating the issues involved and developing solutions to explore.
Of those tools, the separation technologies and pollution prevention information tools are a set
of four individual but interconnected relational knowledge bases in which project teams can
identify viable pollution prevention options during stream-by-stream analysis of process facilities.
These CPAS tools include brief summaries of 518 new or emerging source reduction, recycling,
and end-of-pipe treatment technologies and methods. The user can very quickly sort through the
knowledge bases and summaries based on process stream characteristics and desired separation
or waste minimization performance criteria. This is not new information. It is the existing
knowledge base of the industry, or a significant portion of it, in an organizational structure that
is easier for the design engineer to understand.
There are several developers involved in the first version of these tools include:
- The CWRT
The M.W. Kellogg Company (a large engineering and design firm for oil refineries and
chemical processes)
The National Center for Clean Industrial and Treatment Technologies (CenCITT) based at
Michigan Technological University
The Department of Energy - Office of Industrial Technologies
ENSR Consulting and Engineering
The Bechtel Corporation.
Quite a number of organizations also contributed to the knowledge base:
HazTECH Publishing, Inc.
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High Tech Resources International, Inc.
Chemical Manufacturers Association
Texas Natural Resource Conservation Commission
Hydrocarbon Processing Magazine (Gulf Publishing Company)
AlChE and Chemical Engineering Progress Magazine
U.S. EPA - Superfund Innovative Technology Evaluation (SITE) Program
CWRT sponsors and over 450 other organizations.
Significant funding was also provided by EPA under a cooperative agreement with CPI.
Why was the knowledge base developed?
No such compendium of information exists today. Much of this information may be available
on the Internet, but it is not organized in a fashion that facilitates easy retrieval.
Innovative separation technology information is crucial to economic pollution prevention.
To improve technology transfer between industries and within large organizations. People
often become pigeon-holed; they need to have a source of information to cross-link to other
organizations to find out what they are doing.
To accelerate the consideration of capable separation technologies outside of the industry
sectors where they have been primarily deployed.
Simply getting more information is not the answer. Between 1985 and 1995, the publications
cataloged included:
5,708 on distillation
23,108 on extraction
52, 726 on adsorption
111,520 on membranes.
There is also vendor technology data, unpublished information from conferences, corporate
information, and patent literature.
The benefit of this approach is that it provides guidance to accomplish source reduction and
design process changes. It also provides consideration of other companies' innovative waste
reduction techniques, such as gas-gas and liquid-liquid separation technologies which minimize
or eliminate end-of-pipe streams. It also provides a sizable knowledge base of water reuse,
enabling quicker incorporation of waste and/or energy reduction into operations.
The expected mode of operation in design is to use these tools in the conceptual design phase
or earlier to provide:
Stream by stream flowsheet reviews for alternative technology options
Information based on separation performance or function desired
Alternate searches based on technology group or licensor or vendor name
Quick reviews of many separation options for separation and recovery of contaminants in lieu
of end-of-pipe treatment.
Information typically needed during this early design phase includes:
Phase of the contaminant and carrier stream (gas, liquid, or solid)
Chemical group of the contaminant and carrier stream
Applicable temperature and pressure ranges
Applicable flow rate and contaminant concentration
Contaminant recovery desired
Commercial status desired.
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The pollution prevention tool was released as Version 1.0 in July 1998. Version 2.0 is currently
under development.
Two of the tools were demonstrated (the Gaseous Pollution Prevention Design Options Tool and
the Separation Technologies Tool) and the following scenario was presented.
Scenario - Methanol Production Process
You are an experienced process engineer at a world-scale methanol plant. Your assignment is
to identify and evaluate the two best options for increasing plant production. Because cost is a
very important factor, the two options must take into account all of the current and near-future
safety, health, and environmental requirements for methanol production. The most important
gaseous process effluent streams are:
The synthesis loop purge, and
The refining column overhead gas.
The most important aqueous process effluent streams are:
The fusel oil side-draw from the refining column,
Refining column bottoms, and
Process condensate.
The best process information indicates that the synthesis loop purge is fairly large and contains
hydrogen, carbon monoxide, carbon dioxide, argon, nitrogen, and some methanol. The refining
column overhead gas contains acetone, methanol, dimethyl ether, formaldehyde, and methyl
formate. These two streams are now fed to the boilers for steam generation.
In your data gathering for the aqueous effluent streams, you have found the fusel oil stream to
contain 36% methanol, 6.3% ethanol, 1.5% i-propanol, 0.6% i-butanol, and 55.3% water. This
stream now goes to the boilers as fuel for gathering steam. The refining column bottoms is almost
entirely water with a very low concentration of methanol present and is currently routed to
biological treatment. The process condensate is also mostly water with a small amount of
dissolved gases and some methanol. This stream currently is stripped with steam and recycled
back to the boiler feed waste steam system with the stripping steam recycled to the reformer inlet.
Once the best two options are identified, you intend to use a process simulator, as always in
design, to verify the effects (or lack thereof) on the rest of the production process.
One would go into the gaseous pollution prevention tool in several ways. For instance, in this
case, select first a stream-by-stream analysis. Then select a contaminant, in this case an organic
contaminant such as methanol. Next select a carrier stream: hydrogen. Finally, select "OK" and
the computer will search the database and provide results for the selected parameters. In this
case five technologies were selected; these included: alternative reaction pathways (1), stock pre-
treatment technologies (1), and recycle with (1) and without separation (2). The list includes the
company name and, in some cases, the product name. Simply select the technology of interest
to get more product information, including process information, process diagrams, reported results,
and point of contact.
The organic compounds were changed to phenol and the feed stream to air. Ten technologies
were identified: alternative feedback (1), feedstock pre-treatment (1), recycle with separation (4),
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recycle without separation (3), and consolidated vent and relief systems (1).
CPAS can define the contaminant streams based on the engineering properties of the
contaminant and carrier: nine combinations were listed. Select "gas-gas", choose the carrier (air),
define the feed conditions (temperature of 0 to 100 ฐC), pressure range (14.7 to 50 psia), range
of recovery (greater than 99.9%). The list of potential technologies has been narrowed to four.
Now, say you decide that the recovery can be lower (less than 1,000 ppm) - this is mutually
exclusive with the percentage selected earlier. Then select a commercial status (pilot-plant
testing). The field now includes 24 potential technologies.
This tool is a rather simple concept. By input of basic process information such as pressure,
temperature, carrier gas, etc., the list of technologies can be searched and narrowed. The plan
is to collect and update information from vendors. Version 2.0 will be more ergonomic, especially
in its use. The tool is CD-based. Version 1.0 cannot be updated by the vendors. Version 2.0 will
use a shadow file that will be reviewed by a technical committee before inclusion in the database.
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Comparative Cost Studies
Presented on September 17,1998 by Edward Moretti, Baker Environmental
VOCs can be abated through prevention (e.g., material substitution, process optimization, and
work practices), recovery (e.g., adsorption, adsorption/distillation, condensation, membrane
separation, and volume reduction), and destruction (e.g., thermochemical destruction,
photochemical destruction, plasma/electron beam destruction, and biofiltration). To select an
appropriate reduction strategy, the following steps should be followed:
1) Characterize the emissions by pollutant type and emission rate.
2) Identify appropriate environmental objectives. If regulatory-driven emission control is being
targeted, identify the applicable VOC regulations and VOC abatement options that meet the
regulatory requirements. If emissions control is being targeted in order to comply with waste
minimization efforts, define the corporate culture and business objectives and the VOC abatement
options that eliminate or reduce waste sources.
3) Evaluate VOC abatement options. Assess applicability relative to various operating conditions
and parameters (exhaust stream flow rates, VOC concentrations, and VOC categories - ketones,
alcohols, halogens, and hydrocarbons). Also assess energy requirements and environmental
issues (e.g., secondary environmental impacts, opportunities for recycle, and fugitive emissions).
The following economic factors also need to be considered: pretreatment considerations (e.g,
dilution, preheating, pre-cooling, humidification, dehumidification, particulate removal, entrained
liquid removal), maintenance requirements, and capital, annualized, and social costs.
4) Select the most cost-effective option which meets the environmental objectives.
VOC Abatement Options-Applicability Table
The costs of VOC abatement options vary based on customer specifications, although in general
industrial applications are the most expensive, followed by commercial and then municipal efforts.
VOC abatement costs also vary based on the following: site preparation, instrumentation and
controls, energy costs (fuel and electricity), solvent recovery value, operating/maintenance costs,
VOC concentrations, exhaust stream flow rates, the number of VOCs in the exhaust stream, the
type of VOC, materials of construction, operator requirements, and the number of hours the
system is operated.
Abatement costs can be estimated by using best engineering judgement, published guidance, and
vendor assistance. The following guidance is available on TTN's web page at
http://www.epa.gov/ttn: U.S. EPA COST-AIR, U.S. EPA HAP-PRO, and U.S. EPA OAQPS Cost
Manual. Additional cost guidance can also be obtained from the technical associations and
state/local agencies. U.S. EPA has also developed a number of documents which can serve as
valuable background information sources.
The following comparative costs were developed based on industrial experience and are
consistent with U.S. EPA cost programs.
Natural gas = $2.10 per million BTU
Electricity = $0.04 per kilowatt hour
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Water = $0.08 per 10,000 gallons
Catalyst life = 5 years
Wastewater treatment = $0.50 per pound of VOC
Value of recovered solvent = $0.50 per pound of VOC
Membrane life = 3 years.
A comparative analysis of capital costs for various exhaust abatement options (e.g, catalytic
oxidation, regenerative adsorption, condensation, volume reduction, regenerative thermal
oxidation, adsorption, and membranes) indicates that as gas flow rates rise near 10,000 scfm,
costs drop to the $50 to $350 per scfm range. This analysis also indicates that catalytic oxidation
and adsorption (at gas flow rates over 10,000 scfm) are the most cost-effective. The comparative
annualized costs (without social costs) for catalytic oxidation, regenerative adsorption,
condensation, regenerative thermal oxidation, and adsorption also drop to a relatively narrow
range ($5 to $25 per year per scfm) at flows over 10,000 scfm. In this comparison regenerative
adsorption appears to be the most cost-effective alternative.
The strong public support for environmental protection is leading many companies to consider
waste minimization for VOC abatement. Stockholder pressures on industry to demonstrate
responsible care and strongly held sustainable development/green design values also contribute
to increased interest in waste minimization approaches to VOC abatement. In the future,
innovative technologies that combine pollution abatement with manufacturing process
improvements will probably be more likely to experience commercial success. In fact, according
to the U.S. Commerce Department, corporate spending on so called "integrated technologies" has
more than doubled since 1983.
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Availability of Technology Information, Including Internet-
Based Sources
Presented on September 17,1998 by Heriberto Cabezas, U.S. EPA NRMRL
There are a number of useful technology information sources currently available, including
Internet-based sources. Five of these sources/tools are discussed below. These tools include:
Three software applications for finding or designing solvent substitutes
One software application for quantifying pollution prevention progress
One software application for modifying design parameters to reduce pollution in chemical
processes.
The five tools discussed should not be viewed as a comprehensive list of information sources, but
rather as a subset of the available sources.
SAGE: Solvents Alternatives Guide
SAGE is an Internet-based tool developed by the Surface Cleaning Program at Research Triangle
Institute in cooperation with the U.S. EPA's Air Pollution Prevention and Control Division. It is
available at: http://clean.rti.org/
SAGE works as both an expert system for evaluating various process and chemistry alternatives
for a particular situation and as a hypertext manual on cleaning alternatives. The expert system,
or advisory portion of SAGE, will ask a series of questions about the particular part(s) that need
to be cleaned. These are the same questions that a process engineer would have to answer when
changing a process (e.g., questions on size, part volume, nature of the soil to be removed,
production rate, etc.).
After the question and answer session is complete, the system produces a list of processes and
"chemistries", together with a relative score ranking those alternatives most likely to work for a
particular situation. The relative score will help the user rank the commercially available solvent
alternatives. SAGE can also be used as a reference source. Each alternative will also act as a
hyperlink to further information on the general use of the process or chemistry, safety data, and
case studies.
The Solvent and Process Alternatives Index can be used to access information directly on the
various alternatives listed in SAGE. Ideally this index can be used to retrieve information on a
specific alternative; it will not, however, provide ranking information based on the process
requirements. SAGE also does not assist in the design of new solvents.
CAMD: Computer-Aided Molecular Design
CAMD was developed by R. Gani and P. Harper at the Computer-Aided Process Engineering
Centre, Department of Chemical Engineering at the Technical University of Denmark (DK-2800
Lynghy, Denmark). It can be used to select and design new solvents. CAMD applies the following
"Generate and Test" methodology:
Compounds of the desired type are generated
The generated compounds are screened against the property constraints.
CAMD contains the relevant rules on numbers and types of atoms that can bond to form
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molecules. Compounds are generated based on thermodynamic properties (vapor pressure, etc.)
of the molecules requiring replacement. When an existing molecule is known, the process is
relatively straightforward - there are thousands of chemicals in existence from which to choose.
In cases where the desired molecule does not exist, CAMD uses reasonably sophisticated
computational chemistry to optimize the isomeric configuration of the selected chemical.
The following tools are needed to use CAMD:
Structure generation algorithm
Property prediction methods (usually by a group contribution method or a computational
chemistry method)
Selection/search algorithms (to match the generated molecules to the required properties).
There are five steps during the application of CAMD:
Step 1: Problem formulation (identify solute properties, target properties, and build a
knowledge base)
Step 2: Generation/testing of fragments (develop group description and estimate primary
properties)
Step 3: Generation/testing of final structures (generate isomers and estimate primary,
secondary, functional properties)
Step 4: Generate an atomic description and search database (develop an atomic description
of candidates)
Step 5: Final selection and analysis (sort candidates for specified properties and structural
properties)
PARIS II: Program for Assisting the Replacement of Industrial Solvents
PARIS II was developed by H. Cabezas, R. Zhao (Research Associate, National Research
Council), and J. C. Bare of the U.S. EPA NRMRL (the core program and theory) and S. R. Nishtala
of Research Triangle Institute (Windows interface). PARIS II performs tasks similar to CAMD, but
works in a different manner. Paris has a database of 1,500 chemicals developed by the Design
Institute for Physical Properties Research under the auspices of the AlChE and a Consortium of
Industries.
PARIS II is a second generation solvent design software system. The program finds or designs
a chemical or chemical mixture that matches desired solvent properties. It uses the static,
dynamic, performance, and environmental solvent properties. Various properties can be adjusted
to fine-tune the selection. The software yields application-independent substitute solvents or
mixtures and optimizes the solvent to ensure that a single-phase material is developed and meets
other design requirements. The substitute solvent should act as a "drop-in replacement" - it
should do essentially everything the original solvent did.
Properties that are evaluated by the PARIS II software are:
Static (molecular mass, density, boiling point, vapor pressure, and six activity coefficients)
Dynamic (viscosity, thermal conductivity)
Performance (flash point)
Environmental [air index, total environmental index (eight environmental categories are
evaluated - ozone depletion, global warming, smog formation, acidification, human toxicity-
ingestion, human toxicity-exposure, ecological-aquatic toxicity, and ecological-terrestrial
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toxicity)].
A slide show demonstrating an early version of PARIS is located on the Internet at
www.rti.org/units/ese/p2/PARIS1.html
Pollution Prevention Progress (P2P)
P2P was developed by Greg Carroll, David Pennington (Post-doctoral Research Associate,
ORISE), Robert Knodel [Senior Environmental Employee (SEE) Program Associate], and David
Stephan (Retired, 2/96) of the U.S. EPA NRMRL. P2P is a user-friendly, computer-based tool for
assessing pollution prevented (or sometimes increased) as a result of product redesign,
reformulation, or replacement. There are two versions of the software: Mark I, released February
1995, and Mark II, released July 1997. The software provides:
Before and after snapshots and reports describing pollution prevention accomplished with
respect to media (water, soil/groundwater, and air); categories of pollution (human health,
environmental use impairment, disposal capacity, and life-cycle stages)
Classification for 22 classes of pollution prevented (toxic organics; toxic inorganics;
carcinogens, teratogens, mutagens; fine fibers; heavy metals; radioactives; pathogens; acid
rain precursors; aquatic life toxics; global warmers; biological oxygen demand; chemical
oxygen demand; nutrients; dissolved solids; corrosives; ozone depleters; particulates; smog
formers; suspended solids; odorants; solid wastes; hazard wastes).
P2P also accounts for energy-related pollution associated with pollution prevention. P2P - MARK
II includes the following improvements over Mark I:
A database containing almost 3000 pollutants
Ability to search by CAS No. and synonym
Ability to deal with incompletely-classified pollutants
Ability to report potential regulatory impact.
P2P - MARK III is currently under development. The proposed improvements over the Mark II
version include:
Windows-based program
Accounts for "potencies" of pollutants (i.e., characterization) with respect to environmental
and health impacts
Restructuring of impact categories to improve comprehensiveness, consistency with other
Science Advisory Board (SAB) tools.
WAR: Waste Reduction Algorithm
WAR was developed by D. Young, H. Cabezas, and J. C. Bare of the U.S. EPA, NRMRL and by
G. Pearson of Chemstations, Inc. The WAR algorithm is a design tool for chemical manufacturing
processes which evaluates the environmental impacts of proposed process flow sheets and
assists in reducing pollution. It uses a process simulator along with an associated methodology,
i.e., theory, and a database of chemical environmental impact information to compute indexes
representing the generation of potential environmental impacts inside the process plant, and the
emission of potential environmental impact from the process plant. As changes are made in an
attempt to reduce pollution generated and emitted, these indexes are used to make comparisons
for evaluating the environmental impact of those changes. Whereas P2P tracks pollution
prevention progress, the WAR Algorithm is a manufacturing process design too! for use with
computer process simulators. WAR will be available as part of ChemCAD simulator.
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Paint Spray Booth Design Using Recirculation/Partitioning
Ventilation
Presented on September 17, 1998 by Charles Darvin, U.S. EPA NRMRL
This presentation addresses process modifications to reduce air flow in paint spray booths and
thus control equipment size and cost. The presentation included background information on
paint spray booth design, particularly recirculation issues. The information presented was
obtained over a number of years during a multi-agency effort between the EPA, Department of
Defense, and U.S. Marine Corps. Results from the demonstration of a novel recirculation/flow
partitioning paint spray booth were also included.
Flow Management and Reduction
Both the technical and economic feasibility of various options have to be evaluated when
choosing an emission control strategy. Although it is generally understood within the
engineering field that almost any emission source can be controlled if the necessary funding is
available, few facilities have the wherewithal to pay for expensive control strategies. Since
emission control costs are typically dependent on the volume of air requiring treatment,
strategies to reduce and manage air flow were targeted by EPA and its partners during this
effort.
Paint booths use process air to support a reaction and provide a safe environment during
painting/surface cleaning operations. Since the volume of air requiring treatment is dependent
on process air throughput, EPA and its partners first focused their efforts on techniques to
reduce direct air input. Based on tests performed on 20 to 30 conventional spray booths, EPA
knew that typically more air is processed through conventional systems than is needed to
maintain safe operating conditions. Since spray booth design is regulated under OSHA, EPA
also investigated whether design changes to reduce direct air input would impact compliance
with applicable regulations (e.g., regarding air velocity and internal pollutant concentrations).
EPA and its partners also considered including air recirculation, which has been used to a
limited extent since the late 1970's.
Air Recirculation in Paint Spray Booths
The recirculation concept can reduce control equipment and operating costs (due to smaller
equipment and air volume reductions), thus allowing for the continued use of high
concentration solvent (VOC) coatings. Although recirculation is not a control technology, it is a
booth design concept that enhances emission control alternatives.
Since both capital and operating costs for spray booth emission treatment vary based on air
flow, and since economical control options for controlling these flows are not readily available,
the goal of this effort was to develop a design that reduces exhaust flow rates to air pollution
control systems or the atmosphere.
What is Recirculation?
In conventional, horizontal-flow spray booths, the inlet air flows though the booth in a straight
path and is exhausted through the front of the booth for treatment or to the atmosphere. After
examining these booths, it quickly becomes obvious that to control emissions the total volume
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of air entering and exiting the booths needs to be controlled.
When recirculation is used, a portion of the process exhaust is recirculated in the booth,
reducing fresh intake air and process exhaust volumes. The fresh intake air combines with the
recirculated air to form a homogenous, dilute mixture which complies with safe operating
levels.
Interpreting Government Agency Regulations
When evaluating that a recirculating spray booth could be designed, the following health and
safety issues were researched and addressed:
Does recirculation violate the intent of OSHA regulations 1910.94 and 1910.107?
Does recirculation, as recommended and presently used, present an added safety
burden?
OSHA 1910.107, which covers spray painting using flammable and combustible materials, is
intended to provide a safe operating environment (from a fire hazard perspective) and can be
interpreted to forbid recirculation. However, since most booths operate at combustible element
concentrations that are lower than concentrations needed to sustain combustion (e.g., at 20 to
50 ppm rather than 9,000 to 10,000 ppm), combustion is unlikely.
OSHA 1910.94 (C)(3) on ventilation covers the design and construction of paint booths.
Although this rule does not place restrictions on recirculation, it refers to OSHA 1910.1000 for
health and safety issues associated with toxic and hazardous substances. OSHA 1910.1000
contains concentration limits for toxic and hazardous substances. Under this regulation, if the
concentration(s) in the booth exceeds a specified limit(s), the booth is not deemed acceptable
for human occupation.
After working with EPA on the recirculation issue, in 1994 OSHA determined that recirculated
booths could be used as long as the equivalent toxicity of the stream, as calculated using the
below equation, was less than 1:
ri
I
[concentration],
TWA.
where,
[concentration]! = concentration of each hazardous constituent
TWA, = TWA (time weighted average) of each hazardous constituent (as defined by
OSHAorAIChE).
As a result of this decision, this equation has driven recent paint booth designs.
Concentration Distributions and Their Impact on the Design of Partitioned Booths
Studies of the vertical distribution of contaminants in paint booth exhausts show that
contaminant concentrations formed a gradient in the vertical direction, with concentrations
decreasing with the distance from the floor. By plotting these concentrations (x-axis) versus
height (y-axis) and integrating the area under the graph at a specific height, the amount of
pollution in the air at a given height can be calculated.
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These findings led to the conceptualization of split-flow ventilation systems, which separate the
lean air from the concentrated portion at the bottom of the booth. The end result was a design
for a partitioned/recirculating paint booth, which was capable of recirculating the less
concentrated exhausts (e.g., the leaner flow) and forwarding the more concentrated exhaust
for treatment.
Projections for the Partitioned/Recirculating Paint Booth
Projected recirculated concentrations from a 55,000 cfm air flow contaminated with 5.5.
milligrams per cubic meter (mg/m3) toluene, 4.9 mg/m3 butyl acetate, 0.206 mg/m3 xylene,
0.0046 mg/m3 naphthalene, 0.014 mg/m3 diethyl phthalate, and 0.08 mg/m3 di-n-butyl-
phthalate yielded the following results:
At a recirculation rate of 25%, the equivalent toxicity was 0.03 and the exhaust rate
41,000 cfm.
At a recirculation rate of 75%, the equivalent toxicity was 0.05 and the exhaust rate was
13,750 cfm.
At a recirculation rate of 90%, the equivalent toxicity was 0.139 and the exhaust rate was
5,500 cfm.
A comparison of pre- and post-modification booth flows and costs (with no recirculation and
63% recirculation) revealed the following:
Exhausted flows dropped from 55,000 scfm to 20,210 scfm.
Estimated costs dropped from $1.1 million to $400,000.
Operating costs dropped from $130,000 to $50,000.
Demonstration Results
Under this project, a partitioned/recirculating paint spray booth was used to paint tanks at the
Marine Corps Logistics Base in Barstow, California. During this demonstration, air flow was
reduced from 55,000 scfm to 20,210 scfm. Although the concentrations in the booth increased
significantly over original levels, the equivalent toxicity factor was 0.72 before dilution (with
intake air) and 0.4 after dilution.
Why it Works
Partitioned recirculating paint booths work for the following reasons:
Pollutants are typically heavier than air and will, therefore, fall towards the bottom of the
booth
Heavier solid and gaseous pollutants fall to lower levels of the booth prior to exhaust
Pollutants follow flow streamlines from release point or fall to the booth floor
Recirculated air is relatively clean of paint pollutants
Recirculated concentrations do not approach health and safety limits
Health and safety limits are based on the concentration, not the total volume, of paint
used.
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Summary and Concluding Remarks/Seminar Follow-On Efforts
Presented on September 17, 1998 by Scott Hedges, U.S. EPA NRMRL
Following the breakout sessions, summary and concluding remarks were presented, along with
a brief outline of follow-on efforts.
Summary and Concluding Remarks
There is a need for more guidance documents and information on source reduction - process
design and VOC recovery technologies. There is also a need to incorporate pollution
prevention/waste minimization into VOC recovery/source reduction issues, to improve recovery
cost-effectiveness (in part through flow VOC concentration and flow reduction), and to continue
to convert promising/emerging recovery technologies into viable commercial applications.
Follow-On Efforts
In addition to this seminar summary report, an edited videotape of the seminar presentations will
also be distributed as a technology transfer aid through the U.S. EPA Center for Environmental
Research Information (CERI).
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Breakout Session Summaries
introduction
The purpose of the breakout sessions was to have the VOC Recovery Seminar attendees identify
VOC recovery research needs and barriers preventing companies from employing recovery
strategies. The sessions were also designed to get feedback on technology transfer needs (e.g.,
guidance documents and handbooks)
A questionnaire was sent to each attendee prior to the seminar focusing on three main areas:
barriers, research needs, and technology transfer. The attendees were asked to fill out the
questionnaire and bring it with them to the breakout sessions for discussion. Each breakout
session had a facilitator as well as a note-taker to assist the progression of the discussions. After
the breakout sessions were completed, Seminar attendees reconvened to discuss and highlight
points made in the individual groups. A copy of the questionnaire is included in Appendix B.
Session highlights are summarized below. Individual session notes are included in rough outline
form in Appendix B. A list of each group's participants, along with their affiliation, is also provided
in Appendix B. Each group conducted discussions in different manners, as is seen in this report
and Appendix B. Group B adhered strongly to the prepared questionnaire; Groups A and C, on
the other hand, applied the questionnaire more loosely to their discussions.
Group A
Mr. Daniel Mussatti of U.S. EPA OAQPS summarized Group A's session. He opened by stating
that the three main barriers to VOC recovery technology innovation are: 1) lawyers; 2) government
(EPA); and 3) society.
He first addressed the impact lawyers had on blocking the use and development of innovative
VOC recovery technologies. He noted that, in the absence of regulatory drivers, more incentives
are needed to encourage the use of new technologies. Additionally, barriers that limit technology
innovators from recouping the cost of recovery research need to be removed/reduced. As an
example, he noted that patented technologies dropped significantly in cost after the patent
expires. He suggested, that tax incentives could be given to companies to reduce the cost of a
patented technology to encourage wider use.
He also attributed some of the responsibility for innovation barriers to the "command and control"
attitude common to government officials and regulators. He noted that this attitude resulted in
proven (older) technologies being used more often than new innovative technologies.
He then noted that society's short-term, bottom-line attitude prevents companies and other
organizations from taking the long view on environmental issues. With accountants making most
major decisions, recovery technologies, which at best can be seen as a "cost savings" option, can
never rise to the forefront of organizational agendas.
He concluded by summarizing his group's recommendations for overcoming barriers to innovative
VOC recovery development and use. The following recommendations were made:
Show a cost benefit
Provide tax incentives for investors/developers/users of innovative (risky) technologies (e.g.,
for patent relinquishment)
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Consider increasing regulatory flexibility; focus on the spirit of the law rather than the letter
of the law
Give variances where variances are needed
Examine on a situation by situation basis
Provide performance bonuses to facilities for reducing emissions from stacks, etc.
Increase collaboration between industry/government/academia.
Group B
Dr. Kamalesh Sirkar of NJIT summarized Group B's session. His group started by asking industry
representatives from Intel and Owens Corning to identify what they thought were the biggest
barriers to the use and development of VOC recovery technologies. They responded that solvent
recovery is not profitable due to the low values associated with the recovered materials and
because solvent mixtures (which are more common than a single solvent stream) are more difficult
to recover. As a result, industry is more likely to employ destructive practices (e.g., incineration),
even though they will need to deal with NOX and sulfur oxides (SOX). Session members suggested
that in addition to needing cheaper recovery technologies, industry also needs to receive
recognition for using an 85% effective recovery process instead of a 95% effective incineration
process.
Dr. Sirkar then suggested that recovery be employed at every point of use in a process. He noted
that in the current regulatory environment, however, a permit is needed for every point in the
process. This presents a significant regulatory barrier to VOC recovery use as compared to
incineration, which often requires one control permit for one stream.
Dr. Sirkar then noted the following R&D needs:
Chemical adsorbent performance, cost, and other data need to be compiled and made
available to the public. Material capabilities and behavior with various compounds or
combinations of compounds should be included.
Technologies/media capable of treating low molecularweight polar organic compounds need
to be developed/improved.
Research to identify the operational and performance characteristics of a variety of VOC
recovery technologies/media (i.e., concentration ranges, temperature ranges, percent
removals).
More compact technologies ("unit ops") for small source use.
Dr. Sirkar closed by noting the following technology transfer needs:
Develop a comprehensive data base containing operational and performance characteristics
(i.e., concentration ranges, temperature ranges, percent removals) of a variety of VOC
recovery technologies/media. This database will be particularly useful to facilities and
companies with a combination of VOC recovery needs/situations.
Develop a manual containing standard test methods or test conditions to compare different
techniques.
Group C
Mr. Stephen Adler of CWRT summarized Group C's session. His group started by defining the
biggest problems VOC recovery technologies need to address, namely: 1) low flow, high
concentration streams; or 2) high flow, low concentration streams. He noted that past
improvements treating/reducing stream concentrations, had increased the difficulties faced by
currant VOC recovery developers as they try to treat lower and lower concentration streams.
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He discussed the R&D needs identified by Group C. He noted that some of the needs were more
research-oriented and other more development-oriented. The following R&D needs were
identified:
"Real-world" process demonstrations are needed
There is less need for new ideas to tackle a familiar problem except when costs are
"excessive"
Demonstration funding is needed (e.g., DOE)
Academia, national labs, etc., focus on areas where existing technologies are not cost-
effective
EPA/national labs should focus on helping industry commercialize technologies and not on
basic research
Technology developers need to work with EPA on demonstration sites (testing is expensive)
Government funding for "not-for-profit" efforts is drying up and other sources of funding are
also difficult to obtain (industry is uninterested because the incentives are low)
Funding is going to the wrong places.
Adler then noted the following barriers to VOC recovery development and use:
Must be able to recycle materials for in-plant use, not off-site use. Also, the recycled material
needs to have a recovery value at least $100,000 per year, and a rate of return less than 2
years, for the technology to be used.
Must be able to recycle materials for in-plant use
Many systems are "on-off"
Many technologies are not adaptable to small scale systems ("mom" and "pop" operations
without the means, staff, or knowledge to operate complicated systems). Since technology
providers cannot provide as much service to small providers (a marketing barrier), these
products must be robust, reliable, and require little technical attention.
Lack of funds for commercial "real-world" demonstrations
EPA does not have significant funding to support this
Lack of data prevents technologies from succeeding in the market
Small point sources often do not have the funding to install recovery systems
"White shoe salesman" syndrome - Does the technology really work?
Regulatory uncertainty (e.g., "Any day now" regulations) and State and Federal regulations
which keep being pushed back
Lower cost systems are needed for low concentration streams
Lack of readily available sources of information (e.g., databases) on existing technologies.
Adler concluded his summary by briefly presenting the following suggestions for overcoming
technology barriers:
Better identification of barriers to VOC recovery technology use and development
Provide incentives for new technologies
Eliminate the short term bottom-line mentality
Address hazardous waste issues which present a barrier for establishing new markets for
VOC recovery
Address the fact that a social conscience is not profitable
Tax incentives
Increase regulatory flexibility
Performance bonuses
Trading programs
Increase collaboration between industry and government for demonstration programs.
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Appendix A - List of Seminar Attendees
Stephen Adler
Office: (203) 750 0219
Fax: (203) 750 02 19
E-mail: Stephen.adler@compuserve.com
Center for Waste Reduction Technologies
16 Grey Hollow Road
Norwalk, CT 06850
Frank Alvarez
Office:
Fax:
E-mail:
U.S. EPA, NKMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Jimmy Antia
Office: (513) 556 3637
E-mail:
jimmy. antia@uc. edu
William Asher
Office: (650) 859 2823
Fax: (650) 859 3678
E-mail: bill asher@qm.sri.com
University of Cincinnati
Dept. of Civil & Environmental Engineering, ML 007 1
Cincinnati, OH 4522 1-007 1
SRI International
333 Ravenswood Ave
Menlo Park. CA 94025
Richard Baker
Office: (650) 328 2228, ext 111
Fax: (630) 328 6580
E-mail: mtr@mtrinc.com
Membrane Technology and Research
1360 Willow Road, #103
MenloPar^A 94025
Kathy Baldock
Office: (513) 333 4704
E-mail: (513)651 9528
kathy.baldock@does. hamilton-co.org
Hamilton County DOES
1632 Central Parkway
Cincinnati, OH 452 10
Michael Barrasso
Office: (908) 233 2882
Fax: (908) 233 1064
E-mail: mbarrasso@csmsystems.net
Satish Bhagwat
Office: (740) 321 5265
Fax: (740) 32 1 7567
JatJaiilbhagwat@owenscorning. com
CSM Environmental Systems
200 Sheffield Street, Suite 305
Mountainside, NJ 07092
Owens Coming
2790 Columbus Road
Granville, OH 43023
Dibakar Bhattacharyya
Office: (606) 257 2794
Fax: (606) 323 1929
E-mail: db@engr.uky.edu
University of Kentucky
Department of Chemical Engineering
Lexington, KY 40506-0046
Edward Biedell
Office: (908) 685 4238
Fax: (908) 685 4181
E-mail: edward biedell@reeco.r-c.com
REECO
P.O. Box 1500
Somerville, NJ 08876
Steven Billingsley
Office: (805) 833 9200
E-mail: (805) 833 9300
amerpure@lightspeed. net
Ameripure, Inc.
6701 McDivitt Drive, Suite A
Bakersfield, CA 933 13
Paul Bishop
QSSkQ) 556 3675
E-mail: (5 13) 556 2599
pbishop@boss.cee.uc.edu
University of Cincinnati
Department of Civil & Environmental Engineering
Cincinnati, OH 4522 1-007 1
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Karen Bore 1
Office: (404) 562 9029
E-mail: (404) 562 90 19
borel. karen@epa.gov
U.S. EPA, Region 4
61 Forsyth Street
Atlanta, GA 30303
Heriberto Cabezas
Offke: (513) 569 7350
Fax: (513)5697111
E-mail: cabezas.heriberto@epamail.epa.gov
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Richard Carter
Office:) 793 7600
Fax: (614) 797 7620
E-mail: george.r.carter@cpmx.saic.com
Science Applications International Corporation
655 Metro Place South, Suite 745
Columbus, OH 43017
Bor-Yann Chen
Office:
Fax:
E-mail: chen.bor-yann@epamail.epa.gov
U.S. EPA, NRMRL
27 W. Martin Luther King Drive
Cincinnati, OH 45268
Yoram Cohen
Officb.0) 825 8766
Fax: (3 10) 645 5269
E-mail: yoram@ucla.edu
University of California, Los Angeles
553 1 -E Boelter Hall
Los Angeles, CA
Vern Corbin
Office:
Fax:
E-mail:
Trotter Equipment Company
Cincinnati, OH
James Dale
OJM) 846 5710
Fax: (614) 43 10858
E-mail: jimdale@nucon-int.com
NUCON International
7000 Huntley Road
Columbus, OH 43229
Charles Darvin
OJM) 541 7633
Fax: (919) 5417891
E-mail: darvin.charles@epa.gov
U.S. EPA, NRMRL
MD-61 U.S. EPAMailroom
Research Triangle Park, NC 277 11
John Davison
QJHej) 613 9262
Fax: (503) 613 9299
E-mail: john.davison@intel.com
Intel Corporation
5200 N.E. Elam Young Parkway
Hillsboro, OR 97124
Frank Desantis
Office: (908) 685 4248
Fax: (908) 685 4181
E-mail: frank desantis@reeco.r-c.com
REECO
P.O. Box 1500
Somerville, NJ 08876
Jean Dye
Offke:
Fax:
E-mail:
(513) 5697345
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Joe Enneking
Office: (614) 846 5710
Fax: (614)4310858
E-mail: ioeenneking@nucon-int.com
NUCON International
7000 Huntley Road
Columbus, OH 43229
James Gallagher
Office: (770) 984 4136
Fax: (770) 984 4107
gpia@chevron.com
Chevron Products Co.
2200 Windy Ridge Parkway, Suite 800
Atlanta, GA 30339-5673
64
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Sowmya Ganapathi-Desai
Office: (513) 569 7232
Fax: (5 13) 569 7677
E-mail: ganapathi-desai. sowmya@epamail.epa.gov
U.S. EPA
26 W. Martin Luther King Drive, MS 443
Cincinnati, OH 45268
James Garmaker
Office: (65 1) 778 4307
Fax: (651)7786745
yganriaker@mmm. com
3M Company
Bldg 42 2W-09
P.O. Box 3333 1
St. Paul, MN 55133
Emma Lou George
Office: (5 13) 569 7578
Fax: (513) 569 7585
E-mail; george.emmalou@epamail.epa.gov
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Jayant Gotpagar
Office: (502) 564 4797
Fax: (502) 564 5096
E-maJJ. jayant@engr.uky.edu
University of Kentucky - FFOU
18 Reilly Road
Frankfort, KY 40601
Margaret Groeber
Office: (513) 569 5865
Fax: (513) 569 5864
E-mail: mgroeber@pol.com
Science Abplications International Corporation
2260 Park Avenue, Suite 402
Cincinnati, OH 45206
Doug Grosse
(3ffM) 569 7672
Fax:
E-mail:
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Lee Gruber
Office: (513) 333 4716
Fax: (513) 651 9528
E-mail: lgruber@hamilton-co.org
Hamilton County DOES
1632 Central Parkway
Cincinnati, OH 45210
Ajay Gupta
Office:
Fax:
E-mail:
(3 13) 207 8500
(313)207 8930
Durr Environmental, Inc.
14492 Sheldon Road, Suite 300
P.O. Box 701608
Plymouth, MI 48170
Terry Harris
Qffiha) 467 2470
Fax: (513) 467 2137
E-mail: terry-a.harris.b@,bayer.com
Bayer Corporation
356 Three Rivers Parkway
Addyston, OH 4500 1
Teresa Harten
QffiteO 569 7565
Fax (513) 569 7677
E-mail: harten.teresa@epamail.epa.gov
U.S. EPA, ORD, NRMRL, STD
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Scott Hedges
QffibeD 569 7466
Far: (513) 569 7585
Eetrgak scott@epamail .epa. gov
U.S. EPA, ORD, NRMRL
26 W. Martin Luther King Drive, MSG77
Cincinnati, OH 45268
Lynn Ann Hitchens
Qffite3) 569 7672
Fax:
E-mail:
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati. OH 45268
John Hofmann
Office: (513)4672321
Fax: (513)4672137
E-mail: john-f.hofmann/o;bayer.com
Bayer Corporation
River Road
Addvston. OH 45001
65
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William Jones
Office: (3 12) 886 6058
Fax: (3 12) 886 5824
E-mail: jones.william@epamail.epa.gov
U.S. EPA
77 W. Jackson Boulevard
Chicago, IL 60604
Sumana Keener
(ma) 556 2542
Fax: (513) 556 2522
E-mail: skeener@uceng.uc.edu
University of Cincinnati Environmental Training Institute
1275 Section Road
Cincinnati, OH 45237
Jon Kostyzak
Office: (714) 374 7459
Fax: (714) 374 7469
E-mail: jkosty2ak@mvv-industries.com
M&W Industries, Inc.
Walter Koucky
Office: (513) 569 5860
Fax: (513) 569 5864
E-mail: wkoucky@pol.com
Science Applications International Corporation
2260 Park Avenue, Suite 402
Cincinnati, OH 45206
Rolf Laukant
Office: (630) 279 3464
Fax:
E-mail: prismjr@msn.com
Prism Environmental Equipment
531 S. Monterey
Villa Park, IL 60181
Wayne McDaniel
Office:
Fax:
E-mail:.
Trotter Equipment Company
Cincinnati, OH
Hugh W. McKinnon
Office: (513) 569 7689
Fax: (513) 569 7549
E-mail: mckinnon.hugh@epamail.epa.gov
U.S. EPA, NRMRL
26 W. Martin Luther King Drive, MS 225
Cincinnati, OH 45268
Alberta Mellon
Office: (513) 333 4730
Fax: (513) 651 9528
E-mail: alberta.mellon@does.hamilton-co.org
Hamilton County DOES
1632 Central Parkway
Cincinnati, OH 45210
Edward Moretti
Qffke: (412) 269 6055
E-mail: (412) 269 6097
emoretti@mbakercorp.com
Baker Environmental
420 Rouser Road
Coraopolis, PA 15 108
Dan Murray
Office: (513) 569 7522
Fax: (5 13) 569 7585
E-mail: murray.dan@epamail.epa.gov
U.S. EPA, ORD, NRMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
DanieLMussatti
Office: (919) 541 0032
Fax: (919) 541 0839
E-mail: mussatti.dan@epa.gov
U.S. EPA, OAQPS, ISEG
MD-15
Research Triangle Park, NC 277 11
Ion Nicolaescu
Office: (740) 321 6392
Fax: (740) 321 7567
E-mail: ion.nicolaescu@owenscorning.com
Owens Corning
2790 Columbus Road
Granville, OH 43023-1200
Carlos Nunez
OJM) 541 1156
Fax: (919) 541 7891
E-mail: cnunez@engineer.aeerl.epa.gov
U.S. EPA, NRMRL
MD-61U.S.EPAMailroom
Research Triangle Park, NC 277 11
66
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Stephen Opperman
Office: (616) 845 6679
Fax: (616) 845 6749
E-mail: ranger@t-one.net
Ameripure, Inc
84 North Dennis Road
Ludmgton, MI 4943 1
Dave Polachko
OffibeJ) 248 8878
Fax: (419) 325 4878
E-mail: david.palochko@owenscorning. com
Owens Cornine
One Owens Coming Parkway
Toledo, OH 43659
Craig Patterson
OffibeO 569 7359
Fax: (5 13) 569 7707
E-mail: itcorp.te@epamail.epa.gov
IT Corp
c/o T&E Facility
1600 Gest Street
Cincinnati, OH 45204
Robert Patty
Office: (801) 766 8075
Fax: (801) 766 8076
E-mail: rmpatty@burgoyne.com
The Construction Productivity Institute
568 West 2280 North
Lehi, UT 84043
Paul Randall
Office: (513) 569 7673
Fax: (513) 569 7677
E-mail: randall.paul@epamail.epa.gov
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati. OH 45268
Priya Rangarajan
Office: (606) 323 2976
F_ax: (606) 323 1929
E-mail: prrang01@engr.uky.edu
University of Kentucky
177 Anderson Hall, Chemical Engineering
Lexington, KY 40506
Joseph Rogers
Office: (212) 591 7727
Fax- (212) 591 8895
E-mail: jorogers@aiche.org
Center for Waste Reduction Technologies
3 Park Avenue
New York. NY 10016-5901
Steven Rosenthal
Office: (3 12) 886 6052
Fax: (3 12) 886 5824
E-mail: rosenthal. steven@epamail.epa.gov
U.S. EPA
77 W. Jackson Boulevard
Chicago, IL 60604
Brad Russell
Office: (847) 375 7418
Fax: (847) 375 7982
E-mail: bprussel@uop.com
UOP
50 E Algonquin Road,
P.O. Box 5016
Des Plames, IL 600 17-50 16
Philip Schmidt
Office: (512)471 3118
Fax: (5 12) 471 1045
E-mail: pschmidt@mail.utexas.edu
Chris Schnetzer
Office :
Fax:
E-mail:
University of Texas at Austin
Department of Mechanical Engineering, MC C2200
Austin, Texas 78712
Trotter 'Equipment Company
Cincinnati, OH
Brian Schumacher
Office: (702) 798 2242
Fax: (702) 798 2 107
E-mail: schumacher.briani'Siepamail.epa.eov
U.S.EPA,NERL,ESD-LV
P.O.Box 93478
LasVegW 89193-3478
Mohamed Serageldin
Office: (919) 541 2379
F_ax: (919) 541 5689
E-mai! 3in. mohamcdg:,epamail. epa. gov
U.S. EPA
QAQPS-MD-13
Research Triangle Park, NC 27711
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Larry Shaffer
Office: (614) 846 5710
Fax: (614) 4310858
E-mail: lsharTer@nucon-int.com
NUCON International
7000 Huntley Road
Columbus, OH 43229
Richard Sharp
Fax:
E-mail:
7393
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Subhas Sikdar
569 7528
Fax:
E-mail: sikdar.subhas@epa.gov
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Guy Simes
Office: (513) 569 7845
Fax: (513) 569 7677
E-maJl. simes.guy@epamail.epa.gov
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Kamalesh Sirkar
Office: (973) 596 8447
Fax: (973) 596 8436
E-mail: sirkar@admin.njit.edu
New Jersey Institute of Technology
136 Bleeker Street
Newark, NJ 07102
Johnny Springer
Office: (513) 569 7542
Fax:
E-mail:
Anand Srinivasan
Office: (412) 777 7735
Fax: (412) 777 7447
E-mail: andy.srinivasan.b@bayer.com
Jim Strahan
Office: (616) 845 6679
Eamail: (616) 845 6749
ranger@t-one.net
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Bayer Corporation
100 Bayer Road
Pittsburgh, PA 15205
Ameripure,Inc.
84 North Dennis Road
Ludington, MI 4943 1
Frank Stoy
Office:
Eainail:
(513) 333 4716
(5 13) 65 1 9528
Hamilton County DOES
1632 Central Parkway
CincinnaGFT. 45210
Vivek Utgikar
Office:
Fax: (5 13) 569 7105
E-mail: utgikar.vivek@epamail.epa.eov
U.S. EPA
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Leland Vane
Office: (513) 569 7799
Fax: (513) 569 7677
E-mail: vane.leland@epamail.epa.gov
U.S. EPA, NRMRL
26 W. Martin Luther King Drive, MS 443
Cincinnati, OH 45268
Jerry Waterman
Office: (513) 569 7834
Fax: (5 13) 569 7585
E-mail: waterman.ierry@epamail.epa.gov
U.S. EPA, NRMRL
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Jack Watson
Office: (423) 574 6795
Fax: (423) 576 7468
E-mail: watsonjs@ornl.gov
AIChE Research, New Technology Committee
P.O. Box 2008
Oak Ridge, TN 37831-6178
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Nan Wei
Office:) 420 598 1
Fax: (630) 420 4678
E-mail: nwei@amoco.com
Amoco
150 W. Warrenville Road
Naperville, IL 60563
Jim Wessels
Office:
Fax:
E-mail:
Trotter Equipment Company
Cincinnati, OH
Hans Wijmans
Office: (650) 328 2228, x 118
Fax: (650) 328 6580
E-mail: wijmans@mtrinc.com
Membrane Technology and Research, Inc.
1360 Willow Road
Menlo Park, CA 94025
John Williams
Office: (2 19) 277 2577
Fax: (2 19) 277 3775
E-mail: eps@asme.org
EPS
P.O. Box 6034
South Bend, IN 46660
Walter Wilson
Office: (801) 775 6902
Fax: (801) 777 4306
E-mail: wilsonw@hillwpos.hill.af.mil
Hill Air Force Base
00-ALC/EMC
Ogden, UT 84015
Mike Worrall
Office: (630) 577 0400
Fax: (630)5770401
E-mail: mworrall@amcec.com
AMCEC. Inc.
2525 Cabot Drive
Suite 205
Lisle, IL 60532
Qingzhong Wu
Offibel) 556 2498
Fax: (513) 556 2599
E-mail: wuqg@email.uc.edu
University of Cincinnati
Department of Civil & Environmental Engineering
Cincinnati. OH 4522 1-0071
Robert Zeiss
Office:
E-mail:
(1) (1)177111II
bob.zeiss@us.gases.boc.com
BOC Gases
Hill, NJ Avenue 07974
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Appendix B - Breakout Group Notes and Members
The purpose of the breakout sessions was to address each of the questions summarized in the following
questionnaire. Participants were asked to complete the below questionnaire in advance of the seminar.
B.I Questionnaire - Trends/Issues/Research Needs By industry
To Be Answered BV Consultants. Government Employees. University Representatives. Non-Governmental
Organization Representatives
1) What types of organic (volatile or non-volatile) destruction and recovery technologies and applications
have you evaluated/permitted during the course of your work?
2) What are the relative differences in capital, operating, and maintenance costs between destruction and
recovery systems that you have encountered (if known)?
3) Are there potential cost differences if one uses a life cycle assessment view (i.e., cradle to grave
considerations of materials consumed and byproducts/wastes generated)?
4) Can you identify the barriers for switching from a destruction to a recovery process?
5) Do you have suggestions as to how to minimize or eliminate these barriers?
6) Are there any special problems inherent in the destructive processes that are overlooked because they
are "known or established technologies"?
7) What issues/problems have you encountered with the recycle/ reuse of organics?
To Be Answered Bv Industry Representatives and Manufacturers/Designers/Distributors of Technologies
1) Do you have any organic (volatile or nonvolatile) streams presently treated by destruction that might be
candidates for recovery (if uncertain, assume they may have a potential for recoverability)?
a) If so, describe each of these streams.
b) What are the chemical constituents in each of these organic streams (if possible, include %
volume or weight of each chemical)?
c) What are the organic concentrations in these streams, and what are the stream flow rates?
2) What types of destruction processes do you use to treat your organic streams?
3) What are the approximate capital, operating, and maintenance costs for these processes?
4) Are there potential cost differences if one uses a life cycle assessment view (i.e., cradle to grave
considerations of materials consumed and byproducts/wastes generated)?
5) Can you identify the barriers for switching to a recovery process?
6) Do you have suggestions as to how to minimize or eliminate these barriers?
7) Who is the individual or what is the corporate function in your organization that is key in getting recovery
processes evaluated to replace destructive processes?
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8) Have you evaluated any recovery process, and, if so, what have been your experiences?
9) Are there any special problems inherent in the destructive processes that are overlooked because they
are "known or established technologies"?
10) What issues/problems have you encountered with the recycle/ reuse of organics?
To Be Answered Bv All Seminar Participants
1) What organic recovery research programs do you think should be undertaken and why?
2) What modifications/additions to existing research programs do you think are needed and why?
3) What types of economic/compliance incentive programs are needed to encourage the use of innovative
organic recovery technologies?
4) What improvements in recovery technologies are needed to increase the use of these technologies (in
your facility, with your stakeholders, in industry as a whole)?
5) What sources of information (e.g., how-to manuals, guidance documents, technology handbooks, etc.)
do you think are needed to improve the general understanding of organic recovery technologies as well
as to encourage their use?
8.2 Breakout Group A
B.2.1 Session Participants
The following individuals were members of Group A:
Leland Vane U.S. EPA NRMRL
Joseph Enneking NUCON International
James Carmaker 3M Company
Daniel Mussatti U.S. EPA OAQPS
Philip Schmidt UT at Austin
James Gallagher Chevron Products Co.
Paul Randall U.S. EPA NRMRL
Steven Billingsley Ameripure, Inc.
Scott Hedges U.S. EPA NRMRL.
B.2.2 Session Notes
The following text contains the detailed session notes for Group A in rough outline form.
Can new streams be recovered?
-- Styrene
Butadiene
Refinery streams
Methyl ethyl ketone from paint spray...point source recovery
Polymeric adsorbents
Gasoline remediation... consider economics
Jet methyl tertiary butyl ether out of groundwater
Vapor transfer in tankers
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3M
110 control units - only 25 to address recovery problems
Issues
-- Different solvents
Whether the separation unit can be changed to control (or recover) valuable solvents at the
source
When the process is changed, can quality assurance be guaranteed?
Tremendous resources are needed to change a process
-- The price of recovered material dictates any changes
-- The command control attitude of the Best Available Control Technology (BACT) approach
discourages innovative technologies
-- Industries which have emissions just above regulation levels could have a major incentive to go
below the regulatory levels by using VOC recovery measures
-- New control techniques may not be widely available because the patents are held by the inventor
-- Can tax advantages be given to the inventor to make the technology widely available?
-- Can the rules be changed so that hazardous waste materials are not "arbitrarily labeled"?
-- Intangible costs need to be taken into account (like social costs)
-- Social conscience is not profitable; special tax incentives are needed to encourage the use of
recovery technologies
-- Short sighted versus long term thinking
-- Technology is forcing regulation
Recovery Decision Making Process in Industry
-- Economic justifications are needed
-- Starts at the plant level, gradually winds up
-- The level at which authorization is obtained depends on project size
-- Often a quick return on investment is required
-- Proven technologies are usually preferred
-- Retrofitting is more difficult than new construction
Research Needs
-- The effect of EPA regulations (often anticipated) were underestimated
-- New control technologies sources dried up due to underestimates - NUCON comment
- New markets need to be identified
-- New technologies should be able to selectively extract desired components
-- Reduction in capital costs of recovery systems
-- More support is needed for universities
8.3 Breakout Group B
B.3.1 Session Participants
The following individuals were members of Group B:
Jack Watson AlChE CWRT
Teresa Marten U.S. EPA NRMRL
Walter Koucky Science Applications International Corporation
John Davidson Intel Corporation
Kamalesh Sirkar NJIT
Yoram Cohen UCLA
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James Dale NUCON International
Ion Nicolaescu Owens Corning.
B.3.2 Session Notes
The following text contains the detailed session notes for Group B in rough outline form. As noted in the
session report, Group B strongly adhered to the questionnaire.
1) Do you have any organic (volatile or nonvolatile) streams presently treated by destruction that might be
candidates for recovery (if uncertain, assume they may have a potential for recoverability)?
a) If so, describe each of these streams.
-- Yes, Intel and Owens Corning
-- Intel's response
-- Semiconductor
-- Low to high volatility
-- Methanol
-- Ethanol
-- I PA-ethyl acetate
-- Propylene glycol
-- Xylene
-- Monomethyl ether acetate
-- Recovery but not onsite
-- Currently six recovery units
-- Owens Coming's response
-- Painting
-- Xylene
-- Ethylene glycol
-- Toluene (most common)
-- PVC based streams
-- Toluene
-- Ethylene glycol
- Methanol
-- One incinerator per plant
-- Multiple lines
b) What are the chemical constituents in each of these organic streams (if possible, include percent
volume or weight of each chemical)?
-- Owens Coming's response
-- 40,000 cfm flows
-- High purity streams
-- One central control is easier to permit
-- Collected solvent (potential barrier)
-- Large streams (50,000 cfm)
-- No recovery is currently being performed by Owens Corning
c) What are the organic concentrations in these streams, and what are the stream flow rates?
See response for question 1 b.
2) What types of destruction processes do you use to treat your organic streams?
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-- Incineration at both Owens Corning and Intel
3) What are the approximate capital, operating, and maintenance costs for these processes?
-- No response provided
4) Are there potential cost differences if one uses a life cycle assessment view (i.e., cradle to grave
considerations of materials consumed and byproducts/wastes generated)?
-- Recoup to regenerate
-- Self sufficient
-- Reduced fuel costs
-- Looking at novel technologies
-- Concerns about NOX (thermal treatment)
5) Can you identify the barriers for switching to a recovery process?
-- Intel's response
-- Recovery for incineration has some value
-- Mixed streams and low-value solvents are barriers
-- Destruction generates NOX
-- Silicon in products
-- Creates particulate
-- Contaminates catalysts
-- Semiconductor industry
-- Lower percent efficiency but low NOX and PM
-- Owens Coming's response
-- Capital costs
-- Low solvent values
6) Do you have suggestions as to how to minimize or eliminate these barriers?
-- Intel's response (less focused on capital costs)
--ซ Recovery can be cost effective but currently has lower percent capture than destruction
technologies - improve percent capture
-- Owen Coming's response
-- Reduce capital costs
-- Energy balance issues
-- Process streams are warm and need less energy for thermal treatment than to
cool/condition for recovery
-- Address humidity issues
-- Concentration expansive
-- Low VOC streams
--ซ Reduce potential for dilution
-- Use lower velocity hoods/pick-ups/ovens
7) Who is the individual or what is the corporate function in your organization that is key in getting recovery
processes evaluated to replace destructive processes?
-- Intel's response
- Corporate level decision (e.g., senior vice president)
-- Owens Corning's~response
-- Corporate level decision
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8) Have you evaluated any recovery process, and, if so, what have been your experiences?
-- Owens Coming's response
-- Evaluated and rejected recovery applications
-- Paint lines need cleanup solvents
-- May have on-site uses for recovered solvents (need to investigate)
-- Dr. Yoram Cohen's response (UCLA)
-- Petroleum products (Port Valdez oil tanker)
-- 40,000 tons per year to atmosphere
-- Chlorinated hydrocarbons
-- Low values solvents: economics may not justify recovery, but risk (especially
perceived risk) and public concern regarding incineration should be considered
-- VOCs from tanker loading - incinerate?
- Opted for recovery - economics and public opinion opted for recovery
NUCON's response
-- NUCON sells recovery; does not do economics
-- Customer prefers to do economics
-- Bigger companies are sophisticated at evaluating the cost
-- Regulations are feared (perception of regulation)
-- 50% non chlorinated/50% chlorinated VOCs streams
-- Corrosion increases prices; greater incentive for recovery
9) Are there any special problems inherent in the destructive processes that are overlooked because they
are "known or established technologies"?
NOX
SOX
PM
-- Methyl ethyl ketone
-- Secondary pollutants
10) What issues/problems have you encountered with the recycle/reuse of organics?
-- Intel's response
-- Needs to be high purity - has low value
-- Owens Coming's response
-- Low value solvents - need market for recovered product
11) What organic recovery research programs do you think should be undertaken and why?
-- Kamalesh Sirkar's response (NJIT)
-- Polymeric sorbents (printed literature)
-- Third party comparisons
-- Polar organics - sorbent problems
- Formaldehyde - hydrophilic sorbent claims it works, problem for carbon
- Organics
- More selective membranes
-- In plant VOC recovery devices
- Dilute air streams (250 ppm, 1000 cfm flows)
-- Yoram Cohen's response (UCLA)
-- Polymeric resins - should not be magic
-- Which sorbent (known chemistry) is used should not be just a vendor decision - resins not
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made for all compounds (use correct polymers)
-- Performance not established
-- Rate data - tons of data on carbon (e.g., pH, metals, interferences) but not on polymers, at
least in the "OPEN" literature
12) What modifications/additions to existing research programs do you think are needed and why?
-- Barriers can impede small and large systems
-- Rules can be barriers too
-- Small systems - "record keeping" and "monitoring"
-- Stringency of regulation
-- Small, compact, hydrophilic, low molecular weight systems - also point of use systems for
wastewater
-- Teflon membrane destruction technologies
ozonation of 100 ppm streams
- 2-3 companies in the market
13) What types of economic/compliance incentive programs are needed to encourage the use of innovative
organic recovery technologies?
-- Government incentives
14) What improvements in recovery technologies are needed to increase the use of these technologies (in
your facility, with your stakeholders, in industry as a whole)?
- Technologies for dilute streams (100 ppm), process integration, and optimizing new technologies
-- Combined short bed absorption with pervaporation - small scale application
-- Information on process design as well as chemistry
-- Smaller scale processes for special applications - large companies sell finished products, this limits
creativity
-- Turnkey system versus active media companies is economical
-- Sell systems not membranes
-- Standard tests (American Society of Testing and Materials) to compare media on equal ground
Standard tests for evaluating performance -- can be used to bring more systems to market
15) What sources of information (e.g., how-to manuals, guidance documents, technology handbooks, etc.)
do you think are needed to improve the general understanding of organic recovery technologies as well
as to encourage their use?
-- Owens Coming's response
-- More pilot scale research
-- Database containing available information and knowledge
-- Manual to help integration of technology and provide alternatives when one choice does not
solve the problem
B.4 Breakout Group C
B.4.1 Session Participants
The following individuals were members of Group C:
Stephen Adler AlChE CWRT
Joseph Rogers AlChE CWRT
William Asher SRI International
Charles Darvin U.S. EPA NRMRL
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Richard Baker Membrane Technology Research, Inc.
Carlos Nunez U.S. EPA NRMRL
Bob Patty CPI
Satish Bhagwat Owens Corning
Mohammed Serageldin U.S. EPA OAQPS
Nan Wei Amoco
Walter Wilson Hill Air Force Base
Larry Shaffer NUCON International.
B.4.2 Session Notes
The following text contains the detailed session notes for Group C in rough outline form.
Research and Development Needs
-- "Real-world" demonstration of processes are needed
-- There is less need for new ideas to tackle a familiar problem except when costs are
"excessive"
-- Demonstration funding is needed (e.g., DOE)
-- Academia, national labs, etc., focus on areas where existing technologies are not cost effective
-- EPA/national labs should focus on helping industry commercialize technology and not on basic
research
-- Technology developers need to work with EPA on demonstration sites (testing is expensive)
-- Government funding for "not-for-profit" efforts is drying up and other sources of funding are also
difficult to obtain - industry uninterested because the incentives are low
-- Funding is going to wrong places
What are the Problems?
-- Aluminum coating solvents
-- Blowing hydrochlorofluorocarbons from warehouses - a high flow/low concentration issue
-- High flow, low concentration streams (50,000 cfm/few ppm)
-- Streams with concentrations near 500 ppm and flows less than 5000 cfm
-- Styrene
-- High flow, low concentration streams (200,000 cfm/less than 100 ppm)
Some Conflict Between EPA and OSHA Interests and Concerns
-- EPA wants to push towards concentration/recovery
-- OSHA wants to push towards dilution for worker safety
-- Therefore, need to find balance between the two forces
-- Balance is more difficult to obtain due to the small size of many manufacturers
Barriers
-- Must be able to recycle materials for plant use, not off-site use - needs a recovery value of at least
$100,000 per year and a rate of return less than 2 years
-- Many systems are "on-off"
-- Many technologies are not adaptable to small scale systems because of marketing barriers -
product must be robust, reliable, and require little technical attention
-- Small point sources often do not have the funding to install recovery systems
-- White shoe salesman syndrome - Does the technology really work?
-- Lack of funding for commercial demonstrations
-- EPA does not have the funding to support this
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-- "Any day now" regulations - State, Federal regulations keep getting pushed back
-- Lower cost process systems for low concentration streams
-- Lack of readily available sources of information (e.g., a database) on existing technologies
How to overcome barriers?
-- Identify the barriers
-- Provide incentives for new technologies
-- Eliminate the short term bottom-line mentality
-- Address hazardous waste issues which present a barrier for establishing new markets for VOC
recovery
-- Address the fact that a social conscious is not profitable
-- Use tax incentives
-- Increased regulatory flexibility
- Performance bonuses
- Trading programs
-- Increased collaboration between industry and government for demonstration programs
78 &V.S. GOVERNMENT PRINTING OFFICE: 1999 . 750-101/00064
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