Bill Schrock, Allison Costa, U.S. EPA/OAQPS/SPPD FROM ...

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TECHNICAL MEMORANDUM

TO: Bill Schrock, Allison Costa, U.S. EPA/OAQPS/SPPD

FROM: Eastern Research Group, Inc. (ERG)

DATE: August 2, 2018

SUBJECT: CAA Section 112(d)(6) Technology Review for the Solvent Extraction for

Vegetable Oil Production Source Category

This memorandum summarizes the results of an analysis ERG conducted on behalf of the U.S.

Environmental Protection Agency (EPA) to identify developments in practices, processes, and

control technologies that have occurred since promulgation of the National Emission Standard for

Hazardous Air Pollutants (NESHAP) for the Solvent Extraction for Vegetable Oil Production

Source category. This analysis is part of the EPA review efforts in accordance with section

112(d)(6) of the Clean Air Act (CAA).

This memorandum is organized as follows:

1.0 Introduction

2.0 Background for the Solvent Extraction for Vegetable Oil Production Source

Category

3.0 Developments in Practices, Processes, and Control Technologies

4.0 Control Technology Cost and Emissions Reductions

5.0 Summary

6.0 References

Appendix A – List of Vegetable Oil Production Processes and Facilities

Appendix B – Results of RACT/BACT/LAER Clearinghouse Query

Appendix C – Process Characteristics for Model Facilities

1.0 INTRODUCTION

Section 112 of the CAA requires EPA to establish technology-based standards for listed

source categories that are sources of hazardous air pollutants (HAP). These technology-based

standards are often referred to as maximum achievable control technology (MACT) standards.

Section 112 also contains provisions requiring the EPA to periodically revisit these standards.

Specifically, paragraph 112(d)(6) states:

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(6) REVIEW AND REVISION. – The Administrator shall review, and revise as necessary

(taking into account developments in practices, processes, and control technologies),

emissions standards promulgated under this section no less often than every 8 years.

To comply with this CAA requirement, the EPA conducted a technology review for the

solvent extraction for vegetable oil production MACT standard. For the purposes of conducting

the technology review, the EPA considers “developments” in practices, processes, and control

technologies to be:

• Any add-on control technology or other equipment that was not identified and considered

during development of the original MACT standards.

• Any improvements in add-on control technology or other equipment (that were identified

and considered during development of the original MACT standards) that could result in

additional emissions reduction.

• Any work practice or operational procedure that was not identified or considered during

development of the original MACT standards.

• Any process change or pollution prevention alternative that could be broadly applied to the

industry and that was not identified or considered during development of the original

MACT standards.

• Any significant changes in the cost (including cost effectiveness) of applying controls

(including controls the EPA considered during the development of the original MACT

standards).

2.0 BACKGROUND FOR THE SOLVENT EXTRACTION FOR VEGETABLE OIL

PRODUCTION SOURCE CATEGORY

2.1 Source Category and Source Category Emissions

The current NESHAP for solvent extraction for vegetable oil production was proposed on

May 26, 2000 (65 FR 34252), promulgated on April 21, 2001 (66 FR 19006), and codified at 40

CFR part 63, subpart GGGG. The NESHAP regulates facilities that are major sources of HAP and

that produce crude vegetable oil and meal products by removing oil from eight listed oilseeds

(soybean, cottonseed, canola (rapeseed), corn germ, sunflower, safflower, peanuts, and flax)

through direct contact with an organic solvent. Vegetable oil production that does not use an

organic solvent or that does not use one of the listed oilseeds is not subject to the current NESHAP.

Facilities that refine or process existing (received) vegetable oil are also not subject to the current

NESHAP.

At the time of the original NESHAP rulemaking, there were 106 vegetable oil production

facilities using hexane-based extraction solvent. EPA determined that all the facilities were major

sources and EPA initially estimated that these facilities emit 27,400 tons of n-hexane per year.

Since that time, the number of facilities subject to the NESHAP has decreased due to consolidation

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within the industry. Per review of available emissions data, permits, and consultation with industry

associations, we have identified 89 vegetable oil production facilities that are major sources of

HAP using hexane-based extraction solvent. Appendix A lists the names of the facilities currently

subject to the NESHAP. Hexane emissions from these facilities totaled 13,500 tons in the 2014

National Emissions Inventory (NEI).

The affected sources at a facility utilizing solvent extraction for vegetable oil production

are the emission points which may potentially release n-hexane, a HAP, which is utilized as a

solvent for the extraction. The EPA does not consider n-hexane classifiable as a human carcinogen;

however, long-term human exposure from inhalation of n-hexane is associated with a slowing of

the peripheral nerve signal conduction, which may cause numbness and muscular weakness, as

well as changes to the retina which may cause blurred vision. Short-term exposure to n-hexane is

associated with adverse health effects including irritation of the eyes, mucous membranes, throat

and skin, as well as impairment of the central nervous system including dizziness, giddiness,

headaches, and slight nausea. Because all facilities are using a solvent that consists of an n-

hexane/hexane isomer blend, n-hexane is the only HAP emitted from the solvent extraction of

vegetable oils.

The extraction process is the same for all eight types of oilseeds subject to subpart

GGGG. In each case, oilseeds are crushed, conditioned, and rolled into flakes that are mixed

with the solvent in an extractor. The oil is then dissolved in the solvent. Following this step, the

oil-solvent solution is separated from the flakes and heated to evaporate the solvent. The flakes

are separately desolventized and toasted. The evaporated solvent is then condensed, recovered,

and reused in the process. The desolventized meal is also dried and cooled as a separate product.

All vegetable oil extraction facilities operate some type of solvent collection and recovery

system for the recovery of solvent, although the solvent recovery equipment configuration varies

from facility to facility. The solvent recovery system collects process gas streams from key

process units including extractors, desolventizer-toasters or combined desolventizer-

toaster/desolventizer-coolers (DTDC), meal dryers and coolers, process evaporators, oil/solvent

distillation columns, and wastewater evaporators. The solvent collection and recovery system

then routes the gathered process gas streams to a recovery device that is usually a packed-bed

mineral oil scrubber and may include condensers, solvent distillation systems, and solvent

storage tanks. Hexane emission points in vegetable oil production facilities generally include the

solvent recovery process main vent, meal dryer and meal cooler vents, residual emissions from

crude meal and crude oil, equipment leaks, evaporation from equipment and storage tanks, and

process wastewater. Recovery of the solvent significantly reduces the costs associated with the

extraction and production of vegetable oils. As such, solvent recovery equipment is in many

cases regarded as integral to the process and not treated as a pollution control device. In addition

to collection and recovery systems, facilities may also use source reduction techniques.

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2.2 Summary of Existing MACT

Due to the variability in process and solvent recovery equipment, the current NESHAP

restricts plant-wide hexane emissions from each affected facility rather than requiring individual

controls at each emission point. The current NESHAP includes emission limitations based on the

number of gallons of HAP lost per ton of oilseeds processed. Facilities demonstrate compliance

by calculating a compliance ratio comparing the actual HAP loss to the allowable HAP loss for

the previous 12 operating months. Allowable HAP loss is based on acceptable oilseed solvent

loss ratios provided in the rule in gallons per ton for new and existing sources. Compliance is

demonstrated when the facility’s calculated compliance ratio is less than one (i.e., the actual

HAP loss is less than the calculated allowable HAP loss). Determination of compliance with the

requirements of subpart GGGG requires the facility to keep records of the amount of hexane

purchased, used, and recovered from the oilseed extraction process, the amount of oilseed

processed, and the volume fraction of each HAP exceeding one percent in the extraction solvent

used. Facilities may also adjust their solvent loss to account for cases where solvent is routed

through a closed vent system to a control device that is used to reduce emissions to meet the

standard. This approach allows industry the flexibility to implement the most cost-effective

method to reduce overall HAP loss for individual operations.

During the development of the solvent extraction for vegetable oil production NESHAP,

the EPA utilized two years of monthly data relating to solvent losses in gallons with respect to

tons of oilseed processed. For existing sources, EPA determined the MACT floor for each of the

12 oilseed or process operations as the average of the HAP loss performance levels

corresponding to the top performing 12 percent of sources or the top five for oilseeds for

operations with fewer than 30 sources. For new sources, the MACT floor was based on the

performance level corresponding to the top-ranking source. The MACT solvent loss allowable is

a facility-wide “bubble” over all potential sources of n-hexane emissions. Table 1 presents the

solvent loss limits established in the MACT, expressed in terms of gallons of solvent loss per ton

of oilseed processed.

Table 1. Oilseed Solvent Loss Factors for Determining Allowable HAP Loss

Type of oilseed process

Oilseed solvent loss factor (gal/ton)

Existing

sources New sources

Corn Germ, Wet Milling 0.4 0.3

Corn Germ, Dry Milling 0.7 0.7

Cottonseed, Large 0.5 0.4

Cottonseed, Small 0.7 0.4

Flax 0.6 0.6

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Table 1. Oilseed Solvent Loss Factors for Determining Allowable HAP Loss

Type of oilseed process

Oilseed solvent loss factor (gal/ton)

Existing

sources New sources

Peanuts 1.2 0.7

Canola (Rapeseed) 0.7 0.3

Safflower 0.7 0.7

Soybean, Conventional 0.2 0.2

Soybean, Specialty 1.7 1.5

Soybean, Combination Plant with Low

Specialty Production 0.25 0.25

Sunflower 0.4 0.3

The EPA amended the rule on September 1, 2004 (69 FR 53338) to allow for an

additional compliance option that acknowledged that new low-HAP extraction solvents were

introduced and in use by some facilities in the affected industry. Due to the low HAP level in the

extraction solvents, facilities using this solvent would always be in compliance due to having a

compliance ratio of zero. The amended rule reduced the requirements for facilities using the low-

HAP extraction solvent option such that it is no longer necessary for facilities to measure the

production-related parameters to determine compliance with the NESHAP. The rule continues to

require these facilities to complete the necessary record keeping and reporting requirements to

assure that the solvent used meets the low-HAP criteria.

2.3 Summary of Previously Considered Control Techniques

To assess the MACT floor in the initial rulemaking, EPA developed model plants with

emissions equal to and greater than the MACT floor emission limit, then identified and assigned

potential control techniques capable of achieving the MACT floor. The control techniques

previously considered included:

• Installation of additional desolventizing trays in the desolventizing-toaster;

• Installation of a counter-current desolventizer;

• Installation of an oil dryer in the oil distillation system;

• Installation of a refrigerated condenser on the main vent;

• Venting standing and working losses from fixed-roof storage tanks to the solvent

recovery system; and

• Implementation of a leak detection and repair (LDAR) program for fugitive

equipment leaks.

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The EPA also considered a “beyond-the-floor option”, which would have required a

catalytic incinerator to control the HAP emissions in the combined exhaust from the meal dryer

and cooler vents. A fabric filter would also have been required to remove particulate matter in

the exhaust stream prior to entering the catalytic incinerator. However, the EPA rejected this

option in the final rule because of significantly higher costs per ton of emission reduction.

3.0 SOURCES OF AVAILABLE CONTROL TECHNOLOGY INFORMATION

To identify developments that would be appropriate to consider for control of hexane

emissions from vegetable oil production facilities, we considered several sources of information,

including:

• Air permits and related permitting documentation (applications, inventories, or

consent decrees).

• EPA’s Reasonably Available Control Technology (RACT)/Best Available Control

Technology (BACT)/Lowest Achievable Emission Rate (LAER) Clearinghouse data.

• Subsequent regulatory development efforts.

• Literature search and review.

This section discusses each of these sources and the developments in practices, processes,

and control technologies that we identified, if any.

3.1 Air Permits and Related Permitting Documentation

ERG searched State and Federal websites for major and minor source air permits and

related documentation issued to vegetable oil solvent extraction operations. The operating permits

included Title V operating permits, synthetic minor operating permits, recent BACT/Prevention

of Significant Deterioration (PSD) permits, and other construction permits, where available.

Additional permit documentation included permit applications, supporting documents and

inventories, and consent decrees. ERG reviewed these materials to compare emissions limitations,

configurations, and operating practices between each facility. ERG also reviewed permit materials

for any State-specific regulations regarding HAP emissions from solvent extraction operations

more restrictive than subpart GGGG.

A review of available Title V permits and documentation for solvent extraction facilities

shows there are no new emission sources of HAP at vegetable oil processing plants which were

previously unregulated. Although individual facility configurations may vary, all facilities

continue to use a mineral oil system, which is composed of an absorber or scrubber and may be

combined with evaporators, condensers, refrigerated condensers, solvent distillation systems,

strippers, heat exchangers, and wastewater reboilers as part of the solvent recovery system used to

meet the solvent loss factors required by the NESHAP. A review of Title V permits revealed 14

facilities also implement LDAR programs to reduce fugitive emissions. Facilities may also use

cyclones, baghouses, dust collectors, or oil suppression systems from associated oilseed receiving,

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hulling, milling, flaking, pelleting, or loadout operations, but these control devices are associated

with control of particulate emissions and are not adequate for hexane recovery.

ERG identified at least one process technology, applicable only to specialty soybean

processing operations, that was not previously considered during the development of the 2001

NESHAP in a review of permits and a related consent decree for Archer Daniels Midland (ADM)

(April 9, 2003). The consent decree applied control plans to 26 vegetable oil extraction plants in

10 States for reduction of VOC emissions from soybean, corn germ, sunflower, canola, and

cottonseed processing facilities. The control plan required ADM to implement process

improvements, including the installation of additional condensers, and to establish a VOC solvent

loss ratio (SLR) for affected facilities. The consent decree further required ADM to pilot use of a

Vacuum-Assisted Desolventizing System (VADS) on a single vegetable oil production process

(VOPP) line at one of its specialty soybean processing facilities, and to evaluate the performance

criteria of the VADS. The VADS technology is a new process technology discussed further in

section 4.0 of this memorandum (Developments in Practices, Processes, and Control

Technologies).

3.2 RACT/BACT/LAER Clearinghouse Database

Under the EPA's New Source Review (NSR) program, companies planning to build a new

facility or modify an existing facility must obtain an NSR permit if their operation will cause

criteria air pollutant emissions to increase by a specified amount. The NSR permit is a construction

permit that generally requires the company to minimize air pollution emissions from the new or

modified facility by changing processes to limit emissions of air pollutants and/or installing air

pollution control equipment.

The terms "RACT," "BACT," and "LAER" are acronyms for different program

requirements relevant to the NSR program. RACT, or Reasonably Available Control Technology,

is required for existing sources in areas that are not meeting national ambient air quality standards

(non-attainment areas). BACT, or Best Available Control Technology, is required for new or

modified major sources in attainment areas. LAER, or Lowest Achievable Emission Rate, is

required for new or modified major sources in non-attainment areas.

BACT and LAER (and sometimes RACT) are determined on a case-by-case basis, usually

by State or local permitting agencies. The EPA established the RACT/BACT/LAER

Clearinghouse, or RBLC, to provide a central database of air pollution technology information

(including past BACT and LAER decisions contained in NSR permits) to promote information

sharing among permitting agencies and to aid in future case-by-case determinations. However, the

data in the RBLC are not limited to sources subject to RACT, BACT, and LAER requirements.

Noteworthy prevention and control technology decisions and information may be included even if

they are not related to past RACT, BACT, or LAER decisions.

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The RBLC contains over 5,000 air pollution control permit determinations that can help

identify appropriate technologies to mitigate most air pollutant emission streams. The EPA

designed the clearinghouse to help permit applicants and reviewers make pollution prevention and

control technology decisions for stationary air pollution sources, and includes data submitted by

several U.S. territories and all 50 States on over 200 different air pollutants and 1,000 industrial

processes.

We searched the RBLC database for the Vegetable Oil Manufacturing process category

(70.300) and oilseed-specific subcategories (70.310, 70.320, 70.330, 70.350, and 70.390). We

searched for the pollutant “hexane” to identify facilities that may have installed control

technologies specifically to reduce hexane emissions, as well as the pollutant “VOC” to identify

facilities where VOC is regulated as a surrogate for hexane. We also searched the RBLC database

for the keywords “extraction”, “desolventizer”, “DTDC”, “scrubber”, and “adsorber” to identify

facilities that may have extraction operations and identify facilities that have installed control

technologies to reduce emissions.

The RBLC database search identified 21 active facilities with vegetable oil extraction

operations. Seventeen (17) of these facilities have established BACT limits for the solvent loss

ratio that are more stringent than the SLR provided by GGGG. A review of these facilities did not

reveal any new emissions reduction practices, processes, or control technologies for hexane or

VOC in current use. All 21 facilities reported the use of a solvent recovery system with mineral

oil scrubber or absorber, 12 facilities reported the use of one or more condensers (in combination

with a mineral oil scrubber or absorber), and 13 facilities indicated use of an LDAR program to

monitor and control fugitive emissions. EPA considered all of these process technologies and

control practices previously under the NESHAP for emissions reductions. However, at least one

facility identified and evaluated the use of a cryogenic condenser installed after the mineral oil

absorber as a potential commercially available control option in their determination of BACT.

Additionally, some facilities re-evaluated the use of catalytic incineration for control of exhausts

from meal dryers and coolers as potentially available control options. Section 4.0 of this

memorandum (Developments in Practices, Processes, and Control Technologies) discusses the use

of a cryogenic condenser and the use of catalytic incineration. Appendix 2 presents the relevant

results of the RBLC search.

3.3 Subsequent Regulatory Development

The EPA promulgated the Solvent Extraction for Vegetable Oil Production NESHAP on

April 21, 2001. Since that time, EPA has developed air toxics regulations for additional source

categories that emit organic HAP from similar types of emission sources to those included in the

vegetable oil production category. We have identified and reviewed these similar NESHAP

regulations to identify potential developments in practices, processes, and control technologies

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used to control emissions that may be applicable for use at vegetable oil production facilities using

solvent extraction. In particular, we reviewed several NESHAP with analogous manufacturing

processes including solvent recovery, promulgated or revised after April 21, 2001. A description

of the standards reviewed, and their requirements, follows.

• NESHAP for the Pharmaceuticals Production Industry (40 CFR 63 subpart GGG). The

EPA promulgated this rule in 1998 and revised the rule in 2014. This rule applies to major

source facilities which produce pharmaceutical products. The rule requires that HAP

emissions be controlled for the following emissions points: storage tanks, process vents,

equipment leaks, wastewater collection and treatment systems, and cooling towers.

Facilities must control HAP by meeting an emissions limit or control efficiency

requirement, and a source can use emissions averaging to meet the emissions standards.

This standard requires the reduction of organic HAP emissions by venting emissions

through a closed-vent system to any combination of control devices or recovery devices,

such as absorbers, carbon adsorbers, condensers, flares, boilers, and process heaters. The

control or recovery device must reduce inlet emissions of HAP by 95 weight-percent or

greater, or to outlet concentrations less than or equal to 20 parts per million by volume

(ppmv) as Total Organic Carbon (TOC). There is also an alternative, pollution prevention-

based standard that requires a reduction in the use of HAP solvents during the

manufacturing process.

• NESHAP for Miscellaneous Organic Chemical Manufacturing (MON) Sources (40 CFR

part 63 subpart FFFF). The EPA originally proposed this rule in 2002 and finalized the rule

in 2006. This NESHAP established emission limits and work practice standards for new

and existing MON process units, wastewater treatment and conveyance systems, transfer

operations, and associated ancillary equipment located at major sources of HAP. This

NESHAP requires that affected equipment control any HAP vented from these sources by

routing the vapors to a control device or recovery device that reduces emissions of total

HAPs by 98 percent or to a concentration of 20 ppmv. A control device may include, but

is not limited to, absorbers, carbon adsorbers, condensers, incinerators, flares, boilers, and

process heaters. The rule also provides an alternative, pollution prevention-based standard

that requires reductions in the amounts of toxic air pollutants used during the

manufacturing process.

• NESHAP for Paper and Other Web Coating Sources (40 CFR 63 subpart JJJJ). The EPA

proposed this rule 2000 and finalized the rule in 2002. The rule applies to facilities that

coat paper and other web substrates. The paper and other web coatings source category

emits HAP such as: toluene, methanol, methyl ethyl chloride, ethylene glycol, xylenes,

phenol, methylene chloride, glycol ethers, hexane, methyl isobutyl ketone, cresols, cresylic

acid, dimethyl formamide, vinyl acetate, formaldehyde, and ethyl benzene. MACT for

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these facilities includes reducing HAP emissions by 95 percent for existing web coating

operations and 98 percent for new web coating. The rule requires the use of a capture and

control system where the control device may be a solvent recovery device or oxidizer. Web

coating operations may also reduce emissions by using pollution prevention measures.

• NESHAP for Site Remediation (40 CFR 63 subpart GGGGG). The EPA promulgated this

rule in 2003 and revised the rule in 2006. The 2006 final rule applies to major sources

where remediation technologies and practices are used at the site to clean up contaminated

environmental media (e.g., soil, groundwater, or surface water) or certain stored or

disposed materials that pose a reasonable potential threat to contaminate environmental

media. This regulation requires emissions controls and/or requirements for work practices

for three groups of emission points: process vents, remediation material management units

(tanks, containers, surface impoundments, oil/water separators, organic/water separators,

drain systems) and equipment leaks. The MACT includes reducing HAP from process

vents and remediation material management units by routing the vapors to a control device

that reduces emissions of total HAPs by 95 percent or to a concentration of 20 ppmv.

Subpart GGGGG requires an LDAR program for equipment (e.g., pumps, compressors,

valves, connectors) involved in remediation.

• NESHAP for Halogenated Solvent Cleaning (40 CFR 63 subpart T). The EPA finalized

this rule in 1994 and revised the rule in 2007. The rule requires batch vapor solvent cleaning

machines and inline solvent cleaning machines to meet emission standards reflecting the

application of the MACT. The rule limits solvent emissions by setting facility-wide annual

solvent cleaning emission limits in kg per year. Facilities determine compliance by

maintaining solvent consumption records and conducting materials balance calculations of

overall solvent emissions.

Each of these standards identify HAP emission limits or efficiency standards and allow for

compliance using solvent recovery or control devices, materials balance calculations, and pollution

prevention practices. EPA previously considered or currently allows all of these control practices

under 40 CFR 63, subpart GGGG for emissions reductions.

3.4 Review of Literature

ERG conducted a literature review to identify additional developments and advancements

in preventing and controlling HAP emissions from solvent extraction of vegetable oils. A majority

of the literature reviewed discussed current abatement technologies, such as installation of mineral

oil scrubbers and additional condensers or the use of counter-current desolventizers, and process

improvements such as leakage monitoring or improved collection of escaping vapors from process

systems, storage tanks, and handling areas in exhaust ventilation for subsequent treatment and

solvent recovery. However, in most cases, ERG found insufficient detail in the available literature

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to determine if advancements had occurred since consideration of these options during the original

subpart GGGG rulemaking.

The report titled Guidance on VOC Substitution and Reduction Activities Covered by the

VOC Solvents Emissions Direction (European Commission, 2009) noted that the three most

common methods of VOC control from solvent extraction in Europe include: 1) a condenser,

separator, and wastewater reboiler, 2) mineral oil scrubber, and 3) cryogenic condensation. The

first two technologies are routinely used within U.S. vegetable oil extraction plants subject to

subpart GGGG to meet emissions standards. The report noted that cryogenic condensation is more

common in European installations.

Several reports and studies referred to emerging technologies that have been tested for

vegetable oil extraction, including supercritical fluid extraction (European Commission, 2009;

Reverchon and Marco, 2006), enzyme-aided aqueous extraction (Barnes, 2015; Campbell et al.,

2011; Dijkstra, 2009; European Commission, 2009; Latif et al., 2008), ultrasonic assisted

extraction (Li et al., 2004; European Commission, 2009), and osmotic shock (European

Commission, 2009). These technologies use non-HAP solvent methods for the extraction of a

variety of oils. Section 4.0 of this memorandum (Developments in Practices, Processes, and

Control Technologies) provides further evaluation of these technologies.

4.0 DEVELOPMENTS IN PRACTICES, PROCESSES, AND CONTROL TECHNOLOGIES

4.1 Identified Control Measures for Solvent Extraction from Vegetable Oil Production

This section discusses any identified developments in control measures, work practices, or

operational procedures that were identified during the review and the technological feasibility of

these measures for application in the vegetable oil production industry.

4.1.1 Add-on Control Technology or Other Equipment Not Identified and Considered

During MACT Development

As described in sections 3.2 and 3.5 of this memorandum, ERG’s review identified the use

of cryogenic condensation to reduce emissions of hexane and VOC from the main vent in vegetable

oil extraction operations. Cryogenic condensation is an add-on abatement technology that EPA did

not previously identify during the development of the 2001 NESHAP. Cryogenic condensers work

similarly to refrigerated condensers in that they rely on a cooling agent for the reduction of the

condenser temperature. However, a cryogenic control system uses liquid nitrogen as a cooling

agent to reduce the temperature of the condenser, which may achieve temperatures from -160 °F

to as low as -350 °F; typical refrigerated condensers using chlorofluorocarbons or

hydrofluorocarbons range from -30 to -150 °F (U.S. EPA, 2017; U.S. EPA, 2001). The lower

temperatures achieved by a cryogenic condenser result in greater condensation and removal of

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solvent from the exhaust stream. Cryogenic condensation systems are generally best suited for low

flow rates (<1,000 standard cubic feet per minute (scfm)), high inlet solvent vapor concentrations

(> 1,000 ppmv), and low moisture content (Trembley and Begata, 2014), and are therefore suited

for the conditions of the mineral oil absorber main vent. Cryogenic condensation efficiency

typically exceeds 99 percent for VOC emission reduction (European Commission, 2009).

No VOPPs currently use cryogenic condensation within the United States; however,

cryogenic condensation is in use in Europe and has been evaluated as a control in at least two

BACT/LAER reviews, as they are already used to control similar sources and emissions (i.e.,

VOC) as those that exist at VOPPs. The prior BACT/LAER analyses reviewed the condenser as a

polishing step after the mineral oil absorber. Therefore, EPA considers the use of cryogenic

condensation to be a technologically feasible control option.

4.1.2 Improvements in Add-On Control Technology or Other Equipment (That Was

Identified and Considered During MACT Development)

As discussed in section 2.3 of this memorandum, EPA evaluated the use of a catalytic

incinerator to control HAP emissions from VOPPs as a “beyond-the-floor” option during the

development of the Solvent Extraction for Vegetable Oil Production NESHAP promulgated in

2001. The incinerator would control the combined exhaust from the meal dryer and cooler vents.

EPA included a fabric filter in this evaluation for the removal of particulate matter in the exhaust

stream prior to entering the catalytic incinerator.

Catalytic incinerators contain a bed of active catalyst material that facilitates the overall

combustion reaction. In a catalytic incinerator, the waste stream may be either preheated directly

(using auxiliary fuel) or indirectly by heat exchange with the oxidizer’s post-combustion gas. The

heated gas then passes over the catalyst bed. The catalytic bed has the effect of increasing the

reaction rate and promotes oxidation at lower reaction temperatures than in other thermal

incinerator units, which requires less auxiliary fuel. Meal dryers and coolers in vegetable oil

production operations typically have high flow rates and low inlet concentrations of hexane,

however, there can be significant variability in the volume and concentration during normal

operation as well as during process upsets, malfunctions, and shutdown. Catalytic incinerators can

and have been used effectively at low inlet loadings (1 ppmv or less).1 However, the types of

compounds that can be oxidized are limited due to the poisoning or clogging effect that some

compounds, including particulates, have on the catalyst. Catalytic oxidation is best suited to

streams with low variation in the type and concentration of VOC, and where catalyst poisons or

other fouling contaminants are not present.

1 U.S. EPA. “Air Pollution Control Technology Fact Sheet: Catalytic Incinerator.” Publication Number EPA-452/F-

03-018.

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Catalytic oxidation is not currently used in VOPPs in the United States. However, as

discussed in section 3.2 of this memorandum, catalytic incineration has recently been re-evaluated

as a control in some BACT/LAER reviews, based on its use for control of similar sources and

emissions. Catalytic oxidation has not been selected as a viable control option at VOPPs for several

reasons. First, vent gases from meal dryers and coolers that would be ducted to the incinerator

would cover a wide range of volumes and solvent concentrations, which would impede the

efficiency of the oxidizer. Additionally, the exhaust streams of the dryers and coolers in solvent

extraction plants generally contain compounds that would contribute to fouling of the catalyst bed.

The amount of particulate in the exhaust gas during normal operation is likely to cause plugging

of the inlet screens or catalyst bed of the oxidizer. The exhaust from the meal dryers and coolers

also contain a small amount of aerosolized oil, as well as sulfur compounds that occur naturally in

soybeans and other oilseeds. Although the addition of a fabric filter or other high efficiency

filtration system may reduce particulates in the exhaust stream, the aerosolized oil and sulfur

compounds cannot be similarly removed and would contribute to fouling of the catalyst bed. The

aerosolized oils may also cause carbonization of the oxidizer chamber that could result in a loss of

control efficiency. Therefore, it is unclear that the use of catalytic incineration would result in

reliable emissions reductions over time and the potential for fouling of the catalyst bed would need

to be considered in the cost estimate.

Another concern for catalytic incineration in solvent extraction facilities is related to the

safety of operations. The presence of fugitive hexane vapors at vegetable oil processing plants

presents a fire and explosion hazard, and normal shutdown procedures (including purging hexane

from process units), process upsets, and malfunctions may result in near lower-explosive limit

(LEL)2 conditions in the meal dryer and cooler exhaust. For example, in facility shutdowns, as

each system is purged, the concentration is reduced from greater than 100 percent of the upper

explosive limit (UEL) through the explosive range to less than 10 percent of the LEL. Due to the

flammability of hexane, the National Fire Prevention Association (NFPA) sets a standard for

solvent extraction plants, NFPA 363, that requires that all ignition sources be at least 100 feet from

the extraction process and requires all potential ignition sources be equipped with approved

devices to prevent flashbacks into the process area. We anticipate that these requirements could

further limit the installation of a catalytic incinerator at individual facilities due to space and

property constraints.

Based on the technical and safety concerns identified, EPA considers the use of catalytic

incineration, even with the use of a fabric filter, technically infeasible for meal dryers and coolers

at VOPPs.

2 The LEL is the minimum concentration (by percentage) of a gas or vapor in air that is capable of producing a flash

of fire in presence of an ignition source. The maximum concentration of a gas or vapor that will burn in air is

defined as the UEL. 3 See https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-

standards/detail?code=36.

Page 14

As discussed in section 3.1 of this memorandum, as part of a review of permit materials,

EPA also identified the installation of additional condensers and/or condenser upgrades as a

control technique for control of emissions of HAP from VOPPs. The condensers included extractor

condensers (installed following the extractor and prior to the vent condenser) and once-thru cold

water condensers (following the vent condenser and prior to the mineral oil absorber), which were

required as part of a 2003 consent decree for ADM. The installation of additional condensers as a

control technique was considered at the time of MACT development. ADM evaluated the emission

reduction benefits of the condenser installation at multiple facilities, including seven conventional

soybean VOPPs, two large cottonseed VOPPs, one canola and small cottonseed VOPP, one corn

germ and sunflower VOPP, and three multiseed VOPPs. Each facility installed either an extractor

condenser, a cold-water condenser, or both as part of the consent decree control plan. The

condensers were installed in 2004 and the company provided an evaluation of the emissions

reductions in 2005. The evaluation provided by the company indicated that the condenser upgrades

resulted in minimal emissions reductions, and in some cases reflected no measurable emissions

reductions benefits, particularly for multi-seed plants. Therefore, although many facilities may

install extractor or cold-water condensers as part of an overall facility plan to help meet the SLR,

these upgrades do not appear to provide significant emissions reductions, and are not evaluated

further in this analysis.

We identified no additional improvements or considerations of add-on control or abatement

technologies that were previously considered during MACT development.

4.1.3 Work Practices and Procedures Not Identified and Considered During MACT

Development

ERG identified no additional work practices or procedures that were not already

identified and considered during MACT development.

4.1.4 Any Process Change or Pollution Prevention Alternative that could be Broadly Applied

that was not Identified and Considered During MACT Development

ERG identified several new process technologies that reduce or avoid HAP emissions

during this review. As described in section 3.1 of this memorandum, ERG identified the use of

vacuum-assisted desolventizers at specialty soybean production facilities in a review of a 2003

consent decree and permits issued following the promulgation of the 2001 rule.

Vacuum-assisted desolventizing technology is only in use by a limited number of specialty

soybean facilities and is only applicable to the specialty soybean production process. Specialty

soybean manufacturing varies from conventional soybean manufacturing in that the product is

intended for human consumption and is therefore processed at lower temperatures to minimize the

denaturation of proteins. In specialty soybean manufacturing, flakes are desolventized using either

flash desolventizing, which relies on exposing solvent-laden flakes to superheated solvent vapors

Page 15

for a matter of seconds, or VADS. The vacuum-assisted stripper-cooler process relies on a vacuum

to reduce the boiling point of the solvent, which results in an increased migration of hexane from

the flakes at lower temperatures. The use of lower temperatures results in a less complete

desolventization for specialty soybean products, therefore, solvent losses from specialty soybean

operations are therefore generally greater than in conventional desolventizing.

The consent decree reviewed in this analysis directed the use of VADs technology to

reduce emissions of VOC from a single specialty soybean VOPP line, and provided for an

evaluation of the performance criteria of the VADS prior to installation on additional VOPP lines.

The VADs technology pilot was intended to achieve a 90 percent reduction in VOC emissions

from the specialty soybean lines. The VADs was constructed on the VOPP line in 2004 and the

facility provided a review of its evaluation in 2005. The evaluation provided by the facility

indicated that although emissions reductions were achieved, there was not a substantial emission

reduction benefit and the 90-percent reduction goal was not met.

Currently, 14 VOPPs in the Solvent Extraction for Vegetable Oil Production source

category produce specialty soybean proteins or a combination of specialty and conventional

soybean proteins. Industry-provided data indicate that only four of the 14 VOPPs produce specialty

soybeans using VADS, and that most VOPPs using VADS also have non-VADS equipped lines

using the same extraction and recovery systems. These include one facility with VADs that

operates intermittently (4-6 days per month) when the line is used for specialty processing, one

facility that operates VADs on 3 of 4 specialty lines, one facility with VADS on a single specialty

line and collocated with a conventional line, and one facility with VADs on a single specialty line.

Because all but one of these facilities also has non-VADS equipped lines using the same oil

extraction and solvent recovery systems, there is not sufficient solvent loss data that is fully

representative of VADs performance. Further, in a review of the RBLC, a 2011 BACT review

(RBLC ID IN-0150) of the use of VADs for a specialty soybean processing facility indicated that

VADS have not been recently applied in this industry or similar source categories and were no

longer commercially available. Therefore, although a limited number of VOPPs are using VADs,

this technology is not considered broadly applicable to other specialty soybean facilities or other

VOPP facilities at this time.

As discussed in section 3.4 of this memorandum, ERG identified several additional

emerging technologies in internet searches and a review of available literature. These processes

included supercritical fluid extraction, enzyme-assisted aqueous extraction, ultrasonic assisted

extraction, and osmotic extraction. These are alternative extraction methods which avoid or reduce

the use of HAP-based solvents.

Supercritical fluid extraction involves the extraction of vegetable oils using supercritical

fluids such as carbon dioxide. The carbon dioxide is liquefied under pressure and then heated to

Page 16

the point that it is a supercritical fluid. The carbon dioxide acts as a solvent but is more easily

removed than hexane from the product through simple depressurization. The process results in

much higher solvent yields but is energy intensive due to the high pressure which must be

maintained. (European Commission, 2009). Although supercritical fluid extraction has been

considered in pilot projects for production of biodiesel, it is not currently in use in any VOPPs in

the United States or elsewhere.

In enzyme-assisted aqueous extraction, enzymes are used to degrade the cell walls with

water as the primary solvent. The enzymes may be designed to have a specific mode of action, but

cellulase, hemicellulose, pectinase, and proteases are the most favorable enzymes (Kalia et al,

2001). The process results in a higher quality oil and protein. There is currently one known pilot

plant for enzymatic oil extraction, located in Denmark. (European Commission, 2009)

ERG identified two additional technologies in research studies, including ultrasonic-

assisted extraction, a process that involves the use of ultrasonic waves to break open cell walls to

accelerate the extraction of oil in the existing solvent-based process (European Commission, 2009;

Li, 2002), and osmotic shock extraction, which requires a reaction at osmotic pressure to force

cells in a solution to rupture (European Commission, 2009). There are no known pilot plants for

these technologies.

Although supercritical fluid extraction, enzyme-assisted aqueous extraction, ultrasonic

assisted extraction, and osmotic extraction have been studied for use in vegetable oil extraction

applications, they are not used at any existing solvent extraction plants and are considered novel

technologies that are not yet technologically feasible.

4.2 Summary of Developments in Practices, Processes, and Control Technologies that

are Considered Technologically Feasible

After review of State and Federal air operating permits, the RBLC, recent regulatory

determinations, and relevant literature, we identified the use of a cryogenic condenser after the

solvent recovery system main process vent as a technically feasible control technology for

reducing HAP emissions from VOPPs. The EPA did not previously consider the use of a

cryogenic condenser after the solvent recovery system main process vent during the development

of subpart GGGG, however, this control has been identified as a technologically feasible control

option in use in European installations, as well as included in recent BACT reviews. Therefore,

given the feasibility of this technology, we are considering the use of a cryogenic condenser in

VOPPs in the United States to increase the recovery of hexane from the exhaust stream. Section

5.0 of this memorandum includes a discussion of the costs for these technologies.

Page 17

5.0 COST AND ENVIRONMENTAL IMPACTS

As discussed in section 4.2 of this memorandum, ERG identified a cryogenic condenser

installed after the mineral oil absorber main vent as a feasible control option for VOPPs. ERG

estimated the costs for this control option based on the development of model scenarios which

represent various vegetable oil production facilities. Section 5.1 of this memorandum provides

the model methodology. Section 5.2 of this memorandum includes the control option costs.

Section 5.3 of this memorandum describes the cost impacts.

5.1 Development of Model Scenarios for Estimation of Control Costs

For estimation of control costs, ERG developed six model scenarios to represent the

solvent recovery system main process vent conditions at several vegetable oil processing

operations. ERG developed model scenarios for the following operations:

1) Conventional soybean operations (3 models).

2) Cottonseed operations.

3) Corn germ.

4) Specialty soybean.

We assigned each scenario process characteristics for the solvent recovery system main

process vent that would be generally representative of similar operations in the source category.

For conventional soybean operations, we developed three scenarios representing varying solvent

loss characteristics in order to better represent the range of values of existing facilities. Baseline

emissions were then developed for each of the six scenarios for evaluation of cost-effectiveness.

The following subsections of this memorandum identify the parameters selected and discuss the

estimation of baseline emissions for each model.

5.1.1 Selection of Process Parameters for Model Scenarios

As discussed in section 5.1 of this memorandum, we developed six model scenarios to

represent the processes and emissions in the vegetable oil production source categories. We

selected process parameters for each of six scenarios (three conventional soybean, one

cottonseed, one corn germ, and one specialty soybean model) based on a review of reported 2014

NEI stack parameters, facility permits, manufacturer’s materials (Crown Iron Works Company,

2007), and review of existing literature and materials developed in the 2001 NESHAP (Zukor

and Ali, 2000a, 2000b). We selected a set of general operating characteristics for all model

scenarios; Table 2 lists these general characteristics. We assumed that a commercial grade

hexane solvent (0.64 volume fraction of n-hexane) would be used in all scenarios.

Table 2. General Operating Characteristics for All Model Scenarios

Page 18

Characteristic

Conventional

Soybean (all

scenarios) Cottonseed Corn Germ

Specialty

Soybean

Seed Production

Rate (tons/day)

2,600 1,100 1,100 3,000

Days of

Operation/Year

330 330 330 330

Meal Fraction a 0.81 0.19 0.449 0.162 a 2012 Soya & Oilseed Bluebook, Soyatech, March 26, 2012.

For each model scenario, we developed additional process characteristics for the solvent

recovery system (mineral oil absorber) main process vent. For the main process vent, the process

characteristics assigned include the exhaust temperature, flow rate in actual cubic feet per minute

(acfm), and the solvent concentration of the main vent exhaust stream. We selected the exhaust

temperature and flow rates for each emission point for each scenario based on a review of data

reported to the 2014 NEI, facility permits, and review of existing literature and materials (Zukor

and Ali, 2000a, 2000b). We estimated the solvent concentration in the main vent exhaust stream

as a percentage of the LEL of n-hexane in air. Several VOPP currently monitor the solvent

concentration in the main vent as a percentage of the LEL. The LEL of n-hexane in air is 1.1

percent by volume. The percent LEL we assigned to each model is based on review of facility

permits and BACT reviews, manufacturer specifications, and review of existing literature.

Appendix C provides the parameters assigned to each model scenario.

5.1.2 Calculation of Baseline Emissions for Model Scenarios

Following establishment of the process characteristics of each model scenario, we

calculated baseline emissions estimates for the main process vent for each model. ERG used the

baseline emission estimates to estimate the emissions reductions and the cost effectiveness of the

control options evaluated in each scenario (see sections 5.2 and 5.3 of this memorandum).

In each model scenario, we estimated the baseline emissions of hexane for the main vent

based on the exhaust flow rate of the main vent (acfm), the concentration of the solvent in the

exhaust stream, and the density of the gas stream (adjusted based on the exhaust temperature,

using the Ideal Gas Law). As discussed in section 5.1.1 of this memorandum, the solvent

concentration in the main vent exhaust stream was estimated as a percentage of the LEL of n-

hexane in air (see Appendix C for the percent LEL assigned to each model). ERG used the

following equation to estimate emissions for each model:

EQUATION 1: Main vent (tons hexane/year) =

Flow (ft3/min) x 60 min/hr x hrs/year x Hexane LEL (1.1%) x % of LEL x density (lb/ft3) x 1 ton/2000 lbs

Page 19

The baseline emissions for each model scenario are listed in Table 3.

Table 3. Baseline Emission Rates by Model Scenario

Model Scenario

Main Vent Hexane Emissions

(tons/year)

Conventional Soybean

(Plant 1.1) 11

Conventional Soybean

(Plant 1.2) 35

Conventional Soybean

(Plant 1.3) 112

Cottonseed (Plant 2) 34

Corn Germ (Plant 3) 33

Specialty Soybean (Plant 4) 37

5.2 Control Cost Methodology

To evaluate the potential control costs for a cryogenic condenser on the main vent, ERG

reviewed detailed costs provided from BACT reviews conducted for a facility in the state of

Indiana4. The costs provided in the BACT review were based on a vendor quote for a Linde

Cirrus Cryogenic Condenser and using the methodology from EPA’s Air Pollution Control Cost

Manual (Sixth Edition, January 2002), Section 3, Chapter 2 (Refrigerated Condensers). We

estimated the cryogenic condenser vendor quote was in 2007 dollars based on the date of the

BACT review.

ERG estimated the total capital investment (TCI) for each model scenario by updating

equipment costs from 2007 to 2017 dollars using The Chemical Engineering Plant Cost Index.

Direct costs included purchasing foundation and supports, handling and erecting the structures,

electrical and piping work, insulation for ductwork, painting, and site preparation. Indirect costs

included engineering, construction and field expenses, contractor fees, start-up, performance

tests, and contingencies. ERG also assumed that cryogenic condenser capital costs correlate with

the flow rate of the exhaust gas of the main vent. Therefore, ERG adjusted the TCI for each of

the six model scenarios based on the flow rate of the main vent exhaust in each scenario and

applied the six-tenths relationship shown in equation 1.

Costb = Costa * (Flowa / Flowb)0.6 (Eq. 1)

Where:

Costa = Vendor quote = $1,326,746 ($2017)

4 See RBLC ID IN-0150.

Page 20

Flowa = Flow rate from vendor quote, 225 actual cubic feet per minute (acfm)

Flowb = Flow rate for model scenario

Using the hourly assumptions provided in the prior BACT analysis, ERG estimated direct

annual costs (DAC) with updated labor rates and utility costs. Utilities include the liquid nitrogen

required for the condenser, and this cost was adjusted from the vendor quote by assuming a

linear relationship between liquid nitrogen cost and the flow rate of the exhaust gas of the main

vent. The liquid nitrogen cost was also adjusted from $2007 to $2017 using The Chemical

Engineering Plant Cost Index We adjusted labor rates to reflect May 2017 National Industry-

Specific Occupational Employment and Wage Estimates for NAICS 311200 - Grain and Oilseed

Milling5..

Indirect annual costs (IAC) include overhead, administrative charges, property taxes,

insurance, and capital recovery. ERG recalculated the capital recovery factor assuming an

interest rate of 4.75 percent over 10 years. To account for hexane recovery, ERG used the

baseline emissions to estimate potential solvent recovery and assumed a cost of $2.70/gallon

hexane. ERG adjusted the indirect annual costs and hexane recovery for each of the six model

scenarios based on the flow rate of the main vent exhaust in each scenario. Total annual costs

(TAC) include the direct annual costs and indirect annual costs minus the savings of hexane

recovered. Table 4 below includes the TCI, DAC, IAC, TAC, and hexane recovery costs savings

(HR).

Table 4. Total Capital Cost and Total Annual Costs to Reduce Hexane Emissions at VOPPs Using

Cryogenic Condenser

Facility

Total

Capital

Investment

Direct

Annual

Costs

Indirect

Annual

Costs

Hexane

Recovery

(HR)

Total Annual

Cost (TAC)

Conventional Soybean

(Plant 1.1) $815,602

$1,154,229

$387,374 $11,457

$1,530,145

Conventional Soybean

(Plant 1.2) $1,413,325

$2,259,561

$487,754 $36,454

$2,710,861

Conventional Soybean

(Plant 1.3) $1,873,761

$3,364,894

$565,078 $116,654

$3,813,318

Cottonseed (Plant 2) $1,480,118

$2,406,939

$498,971 $35,413

$2,870,497

Corn Germ (Plant 3) $1,413,325

$2,259,561

$487,754 $34,371

$2,712,944

Specialty Soybean

(Plant 4) $1,326,746

$2,075,339

$473,214 $38,537

$2,510,015

5 See https://www.bls.gov/oes/current/naics4_311200.htm, Occupation code 17-3026. Labor rates are loaded

Page 21

5.3 Cost Effectiveness

After estimating the total capital investment (TCI), total annual costs (TAC), hexane

recovery, and hexane emissions reductions for installation of cryogenic condenser for each

model scenario, we determined the cost-effectiveness, assuming a 99.9 percent reduction. ERG

calculated the cost-effectiveness using TACs and emissions reductions for each model scenario.

Table 5. Cost Effectiveness of Cryogenic Condenser for Model Scenarios

Model

Scenario

Conventional Soybean Cottonseed Corn

Germ

Specialty

Soybean Total

(All

Scenarios) Plant 1.1 Plant 1.2 Plant 1.3 Plant 2 Plant 3 Plant 4

TCI ($) 815,602 1,413,325 1,873,761 1,480,118 1,413,325 1,326,746 8,322,877

TAC ($/yr) 1,530,145 2,710,861 3,813,318 2,870,497 2,712,944 2,510,015 16,147,779

Emissions

Reductions

(tpy)

11

35

112

34

33

37

262

Cost-

Effectiveness

($/ton) 139,243 77,531 34,082 84,511 82,293 67,906 61,694

6.0 CONCLUSIONS

This analysis identified one potential control technology for application in vegetable oil

production facilities. ERG identified the use of a cryogenic condenser after the main vent as an

add-on control option not previously considered during the development of subpart GGGG. This

analysis found that the use of a cryogenic condenser on the main vent is not cost effective for

reduction of HAP. Finally, this analysis found no direct evidence of any additional significant

changes in the practices, processes, and control technologies that may be used by vegetable oil

production facilities.

Page 22

7.0 REFERENCES

Barnes, L. 2015. Ammonia, Hydrochloric Acid, Hydrogen Sulfide, N-hexane, Nitric Compounds,

and Sulfuric Acid in the Food Processing Industry. Great Lakes Regional Pollution Prevention

Roundtable.

Campbell, K. A. Glatz, C.E., Johnson, L.A., Jung, S., de Moura, J. M. N., Kapchie, V., and

Murphy, P. 2011. Advances in Aqueous Extraction Processing of Soybeans. Journal of the

American Oil Chemists' Society, Volume 88, Issue 4: 449–465.

Crown Iron Works Company. 2007. Desolventizer-Toaster-Dryer-Cooler. Roseville, MN.

Available at: http://crownironasia.com/userimages/DTDC%20Main1.pdf. Accessed June 2018.

Dijkstra, A. 2009. Recent developments in edible oil processing. European Journal of Lipid

Science and Technology, 111:855-864.

European Commission – DG Environment. 2009. Guidance on VOC Substitution and Reduction

for Activities Covered by the VOC Solvents Emissions Directive, Final Report. (Directive

1999/13/EC). Available at: http://rs.subsport.eu/images/stories/pdf_archive/legislation/

23_guide_document_vegetable_oil.pdf. Accessed April 2017.

Guinn, J. Domestic Quality Standards and Trading Rules and Recommended Export Contract

Specifications for U.S. Soybeans and Products. U.S. Soybean Export Council. Available at:

https://ussec.org/wp-content/uploads/2015/10/Guinn_Quality_Standards_Trading_Rules2002.pdf

Kalia, V.C., Rashmi, S., and Gupta, M. 2001. Using Enzymes for Oil Recovery from Edible

Seeds. Journal of Scientific & Industrial Research, 60: 298-310.

Latif, S., Diosady, L., and Anwar, F. 2008. Enzyme‐assisted aqueous extraction of oil and

protein from canola (Brassica napus L.) seeds. European Journal of Lipid Science and

Technology, 110: 887-892.

Li, H., Pordesimo, L., and Weiss, J. 2004. High intensity ultrasound-assisted extraction of oil

from soybeans. Food Research International, Volume 37, Issue 7: 731-738.

Reverchon, E. and De Marco, I. 2006. Supercritical fluid extraction and fractionation of natural

matter. The Journal of Supercritical Fluids. Volume 38, Issue 2: 146-166.

T. Roque, M. Correia, and R. Carvalho. 2013. Analysis of the Hexane Loss in a Vegetable Oil

Extraction Unit. Available at:

https://fenix.tecnico.ulisboa.pt/downloadFile/1126295043834814/Artigo_

TeresaRoque69452.pdf. Accessed June 2018.

Soyatech, LLC. 2012. Soya and Oilseed Bluebook. Available at:

https://issuu.com/fpratt/docs/bluebook/174. Accessed June 2018.

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Trembley, John, and Oscar Betata. “Using Cryogenic Condensation to Control Organic Solvent

Vapor Emissions.” Process Cooling, January 10, 2014. Available at: https://www.process-

cooling.com/articles/87491-using-cryogenic-condensation-to-control-organic-solvent-vapor-

emissions. Accessed April 2017.

U.S. EPA, 2018a. 2018. RACT/BACT/LAER Clearinghouse. Available at:

http://cfpub.epa.gov/RBLC/.

U.S. EPA, 2018b. 2014 National Emissions Inventory, version 1. Available at:

https://www.epa.gov/air-emissions-inventories/2014-national-emissions-inventory-nei-data

U.S. EPA, 2017. EPA Air Pollution Control Cost Manual, Sixth Edition. EPA/452/B-02-001.

Available at: https://www3.epa.gov/ttncatc1/dir1/c_allchs.pdf

U.S. EPA, 2002. EPA Air Pollution Control Cost Manual, Seventh Edition. Chapter 2,

Refrigerated Condensers. Available at: https://www.epa.gov/sites/production/files/2017-

12/documents/refrigeratedcondenserschapter_7thedition_final.pdf

U.S. EPA, 2001. EPA Technical Bulletin: Refrigerated Condensers for Control of Organic Air

Emissions. EPA 456/R-01-004. Available at:

https://www3.epa.gov/ttnchie1/mkb/documents/refrigeratedcondensers.pdf

C. Zukor and T. Ali. 2000a. Final Process and Emission Characteristics of Vegetable Oil

Production Model Plants. Alpha-Gamma Technologies, Inc. to Vegetable Oil NESHAP Project

File. Docket No. A-97-59, Category IV-B, Document Number IV-B-6.

C. Zukor and T. Ali. 2000b. Final Model Plant Cost Estimates for Above the MACT Floor

Control Option. Alpha-Gamma Technologies, Inc. to NESHAP: Solvent Extraction for

Vegetable Oil Production Project File. Docket No. A-97-59, Category IV-B, Document Number

IV-B-2.

Page 24

APPENDIX A. VEGETABLE OIL PRODUCTION FACILITIES SUBJECT TO THE NESHAP

Facility State Oilseeds Processed Number of VOPP Lines

Bunge North America - Decatur AL Soybean (conventional) 1

Cargill, Inc. - Guntersville AL Soybean 1

Sessions Company, Inc AL Peanut 1

Planters Cotton Oil AR Cottonseed 1

Riceland Foods, Inc. AR Soybean (conventional), Rice 1

Adams Specialty Oils CA Soybean, canola, safflower, sunflower 1

J.G. Boswell Company CA Cottonseed, safflower 1

ADM - Valdosta GA Soybean (conventional), Large Cottonseed 2

Cargill - Gainesville GA Soybean (conventional) 1

Golden Peanut - Dawson GA Peanut 1

ADM Bioprocessing - Clinton IA Wet corn milling 1

ADM Soybean Processing – Des Moines IA Soybean (conventional) 1

Ag Processing, Inc - Eagle Grove IA Soybean (conventional) 1

Ag Processing, Inc - Emmetsburg IA Soybean (conventional and specialty) 1

Ag Processing, Inc - Sergeant Bluff IA Soybean (conventional) 1

Ag Processing, Inc - Mason City IA Soybean (conventional) 1

Ag Processing, Inc - Manning IA Soybean (conventional) 1

Ag Processing, Inc - Sheldon IA Soybean (conventional) 1

Bunge North America, Inc IA Soybean (conventional) 1

Cargill, Inc. – Des Moines IA Soybean (conventional) (Closed) 1

Cargill, Inc. - Eddyville IA Wet corn milling 1

Cargill, Inc. - Cedar Rapids (East) IA Soybean (conventional) 1

Cargill, Inc. - Cedar Rapids (West) IA Soybean (specialty) 1

Cargill, Inc. - Sioux City IA Soybean (conventional) 1

Cargill, Inc. - Iowa Falls IA Soybean (conventional) 1

CHS Oilseed Processing IA Soybean (conventional and specialty) 1

ADM - Quincy IL Soybean (conventional) 2

Archer Daniels Midland Co – Decatur (East Plant) IL Soybean (specialty) 1

Archer Daniels Midland Co – Decatur (West Plant) IL Wet corn milling, Soybean (conventional) 2

Bunge Milling - Danville IL Wet corn milling, Soybean (conventional) 2

Bunge North America, Inc. - Cairo IL Soybean (conventional) 1

Cargill, Inc. - Bloomington IL Soybean (specialty) 1

Solae – Gibson City IL Soybean (conventional and specialty) 1

Incobrasa Industries Ltd IL Soybean (conventional) 1

Ingredion Inc. - Argo Plant IL Wet corn milling 1

Page 25

Facility State Oilseeds Processed Number of VOPP Lines

Viobin USA IL Soybean (conventional and specialty) 1

Archer Daniels Midland - Frankfort IN Soybean (conventional) 1

Bunge Ltd - Morristown IN Soybean (conventional) (Closed) 1

Bunge North America (East), Ltd IN Soybean (conventional) 1

Cargill, Inc. - LaFayette IN Soybean (conventional and specialty) 1

Consolidated Barge and Grain Co IN Soybean (conventional), Dry corn milling 1

Louis Dreyfus Agricultural Industries LLC IN Soybean (conventional and specialty) 1

Rose Acre Farms, Inc. IN Soybean (conventional) 1

Ultra Soy of America IN Soybean (conventional) 1

Bunge Oilseed Processing Plant -Emporia KS Soybean (conventional) 1

Cargill, Inc. - Wichita KS Soybean (conventional) 1

Northern Sun - Goodland KS Sunflower, Canola 1

Owensboro Grain KY Soybean (conventional) 1

Bunge Corporation - Destrehan LA Soybean (conventional) 1

Perdue Salisbury Feed and Grain - Salisbury MD Soybean (conventional and specialty) 1

Zeeland Farm Soya MI Soybean (conventional) 1

ADM - Mankato MN Soybean (conventional and specialty) 1

ADM – Red Wing MN Soybean (conventional) 1

Ag Processing Inc - Dawson MN Soybean (conventional) 1

CHS Fairmont MN Soybean (conventional) 1

CHS Hallock - Kennedy MN Canola (rapeseed) 1

CHS Oilseed Processing - Mankato MN Soybean (conventional and specialty) 1

Minnesota Soybean Processors MN Soybean (conventional), canola (rapeseed) 1

ADM Soybean Processing - Mexico MO Soybean (conventional) 1

Ag Processing Inc. - Saint Joseph MO Soybean (conventional and specialty) 1

Cargill, Inc. – Kansas City MO Soybean (conventional) 1

Prairie Pride, Inc. MO Soybean (conventional) 1

Delta Oil Mill MS Cottonseed (Closed) 1

Express Grain Terminals LLC MS Soybean (conventional), Wet corn milling, and Other 1

Cargill, Inc. - Fayetteville NC Soybean (conventional) 1

Cargill, Inc. - Raleigh NC Soybean (conventional) (Closed) 1

Perdue Farms Inc. – Cofield NC Soybean (conventional) 1

ADM Northern Sun Division - Enderlin ND Soybean (conventional), sunflower 1

ADM Processing - Velva ND Canola (rapeseed) 1

Cargill, Inc. – West Fargo ND Soybean (conventional) 1

ADM - Fremont NE Soybean (conventional) 1

ADM Soybean Processing - Lincoln NE Soybean (conventional) 1

Page 26

Facility State Oilseeds Processed Number of VOPP Lines

AGP Ag Processing, Inc. - Hastings NE Soybean (conventional) 1

Cargill Corn Milling NA - Blair NE Wet corn milling 1

Archer Daniels Midland - Fostoria OH Soybean (conventional) 1

Bunge North America - Bellevue OH Soybean (conventional and specialty) 1

Bunge Oilseed Processing - Delphos OH Soybean (conventional and specialty) 1

Cargill Soy Processing - Sidney OH Soybean (conventional) 1

Producers Cooperative Oil Mill OK Canola, sunflower, peanut, corn germ (Closed) 1

Archer Daniels Midland Soybean Division - Kershaw SC Soybean (conventional) 1

Hartsville Oil Mill - Darlington SC Cottonseed, peanut 1

South Dakota Soybean Processors SD Soybean (conventional and specialty) 1

Archer Daniels Midland Company - Memphis TN Large Cottonseed 1

Cargill, Inc. - Memphis TN Wet corn milling 1

ADM/Southern Cotton Oil Co - Lubbock TX Large Cottonseed 1

ADM/Southern Cotton Oil Co - Richmond TX Large Cottonseed, Corn Germ 1

Pyco Industries Inc. – Avenue A TX Cottonseed 1

Pyco Industries Inc. – East 50th TX Cottonseed (Closed) 1

Valley Co-op Oil Mill TX Cottonseed 1

Perdue Farms Incorporated – Chesapeake Grain VA Soybean (conventional) 1

Page 27

APPENDIX B. PRACTICES, PROCESSES AND CONTROL TECHNOLOGIES IDENTIFIED FOR SOLVENT

EXTRACTION FOR VEGETABLE OIL OPERATIONS, QUERY OF THE RBLC DATABASE (DECEMBER 2016)

RBLCID Facility Name Date of Last

Determination

Oilseed Process Name Pollutant Control Method Emission

Limits

GA-0062 ARCHER DANIELS

MIDLAND

COMPANY -

VALDOSTA

9/6/2002 SOYBEAN

(CONV.),

COTTONSEED

VEGETABLE OIL

PRODUCTION

VOC CONDENSER

AND MINERAL

OIL HEXANE

SCRUBBER,

LEAK

DETECTION AND

REPAIR (LDAR)

PROGRAM

Compliance

with SLR

limits of

NESHAP;

solvent

consumption

and soybean

production

limits

IA-0029;

IA-0053

CARGILL, INC -

EDDYVILLE

12/18/2001 WET CORN

MILLING

CORN OIL EXTRACTION HEXANE MINERAL OIL

SCRUBBER

SYSTEM

Compliance

with SLR

limits of

NESHAP and

Plantwide

lb/day VOC,

rolling 365-

day limits

2/20/2002 MINERAL OIL

ABSORBER

VOC

BUILDING ASPIRATOR

EXTRACTION AND D-T

ASPIRATION

IA-0085 BUNGE NORTH

AMERICA

5/7/2007 SOYBEAN

(CONV.)

SOYBEAN OIL

EXTRACTION

VOC MINERAL OIL

ABSORBER

Overall SLR

of 0.178 GAL

SOLVENT/T

SOYBEAN;

0.16 TON

GAL VOC/T;

0.2 GAL

HAP/T; 12-

MTH

ROLLING,

IA-0103 AG PROCESSING

SERGEANT BLUFF

3/23/2016

SOYBEAN

(CONV.)

SOYBEAN OIL

EXTRACTION

VOC MINERAL OIL

SCRUBBER; also

operates under

MACT subpart

GGGG, 40 CFR

63.2850(e)(2))

0.145 GAL

SOLVENT

LOSS/T

SOYBEAN,

0.2 GAL

HAP/T; 12-

Page 28

MTH

ROLLING;

Production and

solvent

throughput

limits

IA-0111 DES MOINES

SOYBEAN

PROCESSING

PLANT

7/6/2016 SOYBEAN

(CONV.)

EXTRACTOR AND

DESOLVENTIZER

TOASTER DRYER

COOLER;

EQUIPMENT LEAKS

VOC MINERAL OIL

ABSORPTION

SYSTEM AND

GOOD

OPERATING

PRACTICES;

LDAR

MONITORING

SYSTEM

0.14 GAL

VOC/T

SOYBEAN;

12-MTH

ROLLING;

Total HAP =

Compliance

ratio ≤1.00

(Consistent

with MACT) –

IL-0067 ARCHER DANIELS

MIDLAND

COMPANY (EAST

PLANT)

10/28/2002 SOYBEAN,

SPECIALTY

EXTRACTION-OIL, MAIN

VENT

EXTRACTION-OIL,

SPECIALTY SOYBEAN

PLANT, OVERALL

EQUIPMENT LEAK, OIL

EXTRACTION

VOC VACUUM-

ASSISTED

DESOLVENTIZER

-COOLER,

CONDENSER

AND MINERAL

OIL SCRUBBER -

SUBJECT TO

REQUIREMENTS

FOR INLET TEMP,

OIL FLOW RATE,

OIL TEMP AND

PRESSURE DROP;

LDAR PROGRAM

Limits solvent

consumption

and soybean

production,

sets 10.4 LB

VOC/T

SOYBEAN;

180-DAY

ROLLING

AVERAGE

POINT AND FUGITIVE

FINAL (WHOLE

FACILITY)

MINERAL OIL

ABSORBER,

LEAK

DETECTION AND

REPAIR

PROGRAM

(LDAR)

BACT applies

facility wide

VOC limit of

0.503 GAL/T

SOY OIL

based on

NESHAP

SLRs for new

source

specialty

Page 29

soybean and

existing

conventional

soybean,

individual

VOC limits for

extractor, meal

dryer

IL-0125 ADM QUINCY 06/30/2017 SOYBEAN,

CONV.

VEGETABLE OIL

PRODUCTION PROCESS

VOC Limits total surface

area of solvent

recovery system,

provides for MOS

with 95% control,

sets residence time

for DT and requires

4 recovery trays,

requires LDAR

0.175 gal/ton

soybeans

processed

IN-0150 LOUIS DREYFUS

AGRICULTURAL

INDUSTRIES LLC

8/13/2013 SOYBEAN,

CONV.

SOYBEAN OIL

EXTRACTION PLANT

AND MEAL DRYER AND

COOLER

VOC COMBINED

CONDENSER

AND MINERAL

OIL SCRUBBER

SYSTEM, LDAR

PROGRAM

Sets individual

VOC limits for

Mineral Oil

Scrubber and

Meal

Dryers/Coolers

and Overall

Facility-wide

SLR: 0.141

GAL/T

SOYBEAN

IN-0209 CONSOLIDATED

GRAIN AND

BARGE CO.

6/8/2016 SOYBEAN,

CONV.

EXTRACTION SYSTEM VOC MINERAL OIL

ABSORBER

0.048 LB

VOC/TON

DTDC COOLER 0.152 LB

VOC/TON

DTDC DRYERS 0.152 LB

VOC/TON

OVERALL SOLVENT

LOSS RATIO

0.19 GAL

VOC/TON

Page 30

MN-0065 ADM - MANKATO 1/22/2007 SOYBEAN,

CONV.

SOYBEAN OIL

EXTRACTION

HEXANE MAIN VENT W/

CONDENSER,

MINERAL OIL

ABSORBER, AND

LDAR.

0.15

GALVOC

/TON

MN-0092 CHS HALLOCK 05/02/2017 RAPESEED CANOLA OILSEED

PROCESSING

VOC MINERAL OIL

SCRUBBER,

GOOD SOLVENT

RECOVERY

PRACTICES,

LDAR

0.29 gal/ton of

canola oilseed

MO-0075 AG PROCESSING,

INC. – ST. JOSEPH

8/30/2007 SOYBEAN,

CONV.

REFINERY PLANT AND

OIL EXTRACTION

PROCESSES

HEXANE Evaporators,

condensors, MOS;

LDAR

requirements;

solvent storage tanks

routed to solvent

recovery; vapor

recovery tray

located below

sparge tray of

Desolventizer

Toaster

Sets facility

SLR to 0.145

gal solvent/ton

MO-0082 ARCHER DANIELS

MIDLAND-

MEXICO

4/1/2015 SOYBEAN,

CONV.

SOYBEAN OIL

EXTRACTION

VOC USE OF

EVAPORATORS

AND

CONDENSATION

FOR SOLVENT

RECOVERY AND

UNCONDENSED

VAPORS ROUTED

TO A MINERAL

OIL ABSORBER.

SOLVENT;

STORAGE -

BREATHING AND

WORKING

LOSSES ROUTED

TO SOLVENT

RECOVERY

0.15 GAL

SOLVENT/T

SOYBEAN,

12 MTH

ROLLING;

0.171 GAL

SOLVENT

LOSS/T

DURING

SSM

PERIODS

Page 31

SYSTEM;

PROCESS,

FUGITIVE - LDAR

PROGRAM,

CHILLER TO

OPERATE FROM

APRIL TO

OCTOBER

ND-0027 WEST FARGO

OILSEEDS

PROCESSING

PLANT

10/16/2012 SUNFLOWER

CANOLA

FLAX

EXTRACTION AND

REFINING

VOC CONDENSERS

AND MINERAL

OIL SCRUBBER

0.23 GAL

VOC/TON; 12

MTH

ROLLING

*NE-0024 CARGILL - BLAIR

PLANT

12/2/2015 WET CORN

MILLING

CORN GERM OIL

EXTRACTION PROCESS

HEXANE Complies with

NESHAP SLR

limits

NE-0048 ARCHER DANIELS

MIDLAND -

FREMONT

2/4/2009 SOYBEAN SOYBEAN OIL

EXTRACTION

VOC MINERAL OIL

SCRUBBER W/

SOLVENT

RECOVERY

CONDENSER,

LDAR PROGRAM

0.165 GAL

SOLVENT

LOSS/T

SOYBEAN,12

-MTH

ROLLING

*NE-0059 AGP SOY 8/18/2015 SOYBEAN SOYBEAN EXTRACTION

PROCESS

VOC MINERAL OIL

ABSORBER

(Includes

observations for

leaks and corrective

action)

0.145 gal

solvent/ton

soybean

-Complies

with GGGG

for SSM

OH-0251 CENTRAL SOYA

COMPANY INC.

7/24/2008 SOYBEAN,

SPECIALTY

AND CONV.

EXTRACTION

OPERATION

(CONVENTIONAL)

HEXANE

CONV. – 3

CYCLONES,

CONDENSER,

AND ABSORBER

SPECIALTY – 3

BAGHOUSES

AND

CONDENSER

0.388 GAL/T

rolling 6-mo.

weighted AVG

(applies to

specialty and

conventional

soybean lines),

Complies with

NESHAP SLR

Limits

EXTRACTION

OPERATION (SPECIALTY

W/ HEXANE)

Page 32

*OK-0156

(Note:

Constructi

on has

never

been

initiated

for this

facility)

NORTHSTAR AGRI

IND ENID

12/6/2016 RAPESEED VOC STORAGE

(HEXANE)

VOC MINERAL OIL

SCRUBBER, VENT

CONDENSER

0.29 GAL

SOLVENT

LOSS/TON,

12-MONTH

ROLLING

EXTRACTION

WASTEWATER

EVAPORATOR

CRUDE MEAL

EMISSIONS

DESOLVENTIZER/

TOASTER

157

DEGREES, 1

HR AVG DRYER/COOLER DESOLVENTIZER

EQUIPMENT LEAKS LDAR PROGRAM

(NFPA 36)

PA-0308 PERDUE

AGRIBUSINESS

LLC/MARIETTA

05/05/2016 NEW

SOYBEAN OIL

EXTRACTION

FACILITY

EXTRACTION PROCESS VOC Good Operating

Practices;

LDAR

0.125 gal/ton

of soybeans

solvent loss

ratio

MEAL DRYER

MEAL COOLER

SC-0118 ARCHER DANIELS

MIDLAND CO. -

KERSHAW

FACILITY

3/30/2015 SOYBEAN,

CONV.

SOYBEAN OIL

EXTRACTOR

HEXANE MINERAL OIL

SCRUBBER,

COLD WATER

CONDENSER,

AND

EXTRACTOR

CONDENSER

0.18 gallons of

hexane loss

per ton of

soybeans

processed

VA-0327 PERDUE GRAIN

AND OILSEED,

LLC

7/12/2017 SOYBEAN,

CONV.

LDAR PROGRAM 0.18 gallons

solvent/ton of

beans

processed.

Upon startup

of the new

extractor the

SLR shall not

exceed 0.152

gallons

solvent/ton of

beans

processed.

Page 33

APPENDIX C. PROCESS CHARACTERISTICS FOR MODEL FACILITIES

The following table presents the process characteristics for the solvent recovery system main process vent for six model scenarios that

would be generally representative of similar operations in the source category.

Model Scenario Temperature

(°F)

Flow Rate

(acfm)

Hexane Outlet

Concentration (ppmv)

Baseline n-

Hexane

Emissions

(tons/yr)e

1.1 Conventional soybean 1a 90 100 2200 11

1.2 Conventional soybean 2b 90 250 2750 35

1.3 Conventional soybean 3c 90 400 5500 112

2 Cottonseedb 150 270 2750 34

3 Corn germb 116 250 2750 33

4 Specialty soybeand 100 225 3300 37 a Parameters based on data reported to the 2014 NEI, permit data, state modeling, and review of existing materials developed in the 2001 NESHAP (Zukor and

Ali, 2000a, 2000b). Outlet concentration based on 20% of LEL. b Parameters based on data reported to the 2014 NEI, permit data, and review of 2001 NESHAP materials. Outlet concentration based on 25% of LEL. c Parameters based on data reported to the 2014 NEI, permit data, and review of 2001 NESHAP materials. Outlet concentration based on 50% of LEL. d Parameters based on data reported to the 2014 NEI and permit data. Outlet concentration based on 30% of LEL. e See section 5.1.2 of this memorandum for calculation of baseline n-hexane emissions.