Waste Minimization for Selected Residuals
in the Petroleum Refining Industry
Hazardous Waste Minimization and Management Division
Office of Solid Waste
December 1996
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PREFACE
This document was developed by the United States Environmental Protection Agency
(U.S. EPA), Office of Solid Waste, Waste Minimization Branch. Science Applications
International Corporation (SAIC) assisted in the development of this document in fulfillment of
Contract No. 68-W4-0042, Work Assignment 1-10.
The Agency would like to acknowledge the American Petroleum Institute for the helpful
comments they provided on this document.
For further information, please contact:
U.S. EPA
Hazardous Waste Minimization and Management Division
401 M Street, S.W., 5302W
Washington, DC 20460
Phone: (703)308-8414
Fax: (703) 308-8433
DISCLAIMER
This document has been subjected to U.S. Environmental Protection Agency's peer and
administrative review and approved for publication. This document is intended as advisory
guidance only in developing approaches for pollution prevention. Mention of trade names or
commercial products does not constitute endorsement or recommendation of use.
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Table of Contents
I. Introduction 1
II. Industry Overview 4
A. Petroleum Refining Industry Profile 4
B. Process Descriptions 5
III. Residual Descriptions and Source Reduction Practices for Residuals of Concern 9
Crude Oil Tank Sediment 9
Unleaded Gasoline Tank Sediment 10
Residual Oil Tank Sediment 11
CSO Sediment and/or Filter Solids 13
Desalting Sludge 14
Catalytic Cracking Catalyst and Fines 15
Hydrotreating/Hydrorefming/Hydrocracking Catalyst 15
Reforming Catalyst 17
Catalyst from Isomerization 18
Treating Clay from Isomerization/Extraction 19
. Sulfuric Acid Alkylation Sludge and Catalyst 20
FฃF Alkylation Catalyst and Sludge 21
Acid Soluble Oil (ASO) from HF Alkylation 22
Treating Clay from Alkylation 23
Catalyst from Polymerization 24
Off-spec Sulfur, Sulfur Sludge, Spent Amine and Sulfur Catalyst 24
Thermal Processing Fines and Off-Spec Product 26
Off-specification Product and Process Sludge from Residual Upgrading 27
Spent Treating Clay from Lube Oil Filtering 28
Spent Caustic .' 28
Spent Treating Clay from Clay Filtering 28
IV. Review of Data Sources 30
A. RCRA ง3007 Survey Section XI 32
B. RCRA ง3007 Survey Section VI 33
C. Site Visits 34
D. Journal Articles 34
V. Conclusions 55
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List of Tables
Table 1.1. Petroleum Refining Residuals Identified in the EDF/EPA Consent Decree 3
Table III-l. Volume Reduction Methods Used for Crude Oil Tank Sediment 10
Table III-2. Volume Reduction Methods Used for Unleaded Tank Sediment 11
Table III-3. Volume Reduction Methods Used for Residual Oil Tank Sediment 12
Table III-4. Volume Reduction Methods Used for CSO Sediments and/or Filter Solids 14
Table ni-5. Volume Reduction Methods Used for
Hydrotreating/Hydrorefining/Hydrocracking Catalyst 17
Table III-6. Volume Reduction Methods Used for Reforming Catalyst 18
Table IV-1. Summary of Pollution Prevention Information Available from Section XI
of Surveys 35
Table IV-2. Detailed Residual Elimination Information Available from Section XI of Surveys . 37
Table IV-3. Detailed Regulatory Barriers Reported from Section XI of Surveys 39
Table IV-4. Recycling of RCs Reported in Section VI of Survey 41
Table IV-5. Summary of Waste Minimization Information Available from Engineering
Site Visits 43
Table IV-6. Bibliography to Waste Minimization Documents 45
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I. Introduction
The U.S. Environmental Protection Agency (EPA) is directed in section 3001(e)(2) of the
Resource Conservation and Recovery Act (RCRA) (42 U.S.C. ง6921 (e)(2)) to determine
whether to list as hazardous wastes a number of different wastes including those of the petroleum
refining industry. A lawsuit by the Environmental Defense Fund (EDF) in 1989 resulted in a
consent decree approved by the court, that sets out an extensive series of deadlines for making the
listing determinations required by Section 3001 (e)(2). The deadlines include those for making
final listing determinations as well as for concluding various related studies or reports on the
industries of concern. With respect to the refining industry, the consent decree identifies 14
specific residuals for which the Agency must make listing determinations and an additional 15
residuals for which the Agency must conduct a study. These 29 residuals, subsequently referred
to as the Residuals of Concern (RCs), are listed in Table 1.1. As a result of the consent decree,
the Agency embarked on a project to determine whether these 29 RCs pose a threat to human
health and the environment and to develop a basis for making such a determination. As a result of
the preliminary evaluation of the waste subject to the listing determination, EPA proposed a rule
in which eleven wastes were not to be listed and three wastes were to be listed as hazardous
wastes: K169, K170, and K171 (clarified slurry oil storage tank sediments and/or filter/separation
solids from catalytic cracking, catalyst from hydrotreating, and catalyst from hydrorefining,
respectively) (60 FR 57747, November 20, 1995). The final determination will be issued under
the applicable terms of the consent decree.
As part of the Agency's current investigation of residuals from petroleum refining, the
Agency conducted engineering site visits at 20 refineries to gain an understanding of the present
state of the industry. -These 20 refineries were randomly selected from the 185 refineries
operating in the continental United States in 1992. The Agency conducted record sampling and
analysis of the RCs. During the record sampling timeframe, an additional 6 facilities were
randomly selected to increase sample availability. Approximately 100 record samples were
collected and analyzed. Concurrently, the Agency developed, distributed and evaluated a census
survey of the industry.
Part of the investigation is to evaluate waste minimization opportunities for these RCs that
have been implemented by the industry. Both source reduction and recycling techniques were
reviewed and are described in this document. Source reduction is where the volume and/or
toxicity of the residual is reduced. Recycling is where the residual is put to a useful purpose.
Only those source reduction and recycling opportunities that are used, or could be applied, to the
29 RCs are reported here.
This report is organized as follows:
Section II provides an industry overview, process description, and process flow
diagrams.
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Section III presents residual descriptions for each of the 29 RCs and what source
reduction options exist.
Section IV presents the sources used, describes major findings, and evaluates the
quantity and quality of waste minimization information for each source.
Section V is the conclusion.
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Table 1.1. Petroleum Refining Residuals Identified in the EDF/EPA Consent Decree
SludgesXSediments:
Clarified slurry oil sediments and filter solids from catalytic cracking (L) (CSO sludge)
Unleaded storage tank sediments (L)
Crude storage tank sediments (L)
Process sludge from sulfur complex and H2S removal facilities (L) (sulfur complex sludge)
Sludge from HF alkylation (L)
Sludge from H2SO4 alkylation (L)
Desalting sludge from crude desalting (S)
Residual oil storage tank sludge (S)
Process sludge from residual upgrading (S)
Catalysts:
Catalyst from catalytic hydrotreating (L)
Catalyst from catalytic reforming (L)
Catalyst and fines from catalytic cracking (L) (FCC catalyst and FCC fines)
Catalyst from catalytic hydrorefming (L)
Catalyst from H2SO4 alkylation (L)
Catalyst from sulfur complex and H2S removal facilities (L) (Claus and tail gas treating catalysts)
Catalyst from isomerization process (S)
Catalyst from catalytic hydrocracking (S)
Catalyst from polymerization (S)
Catalyst from HF alkylation (S)
Off-Spec Products:
Off-spec product and fines from thermal processes (L)
Off-spec product and fines from residual upgrading (S)
Off-spec product from sulfur complex and H2S removal facilities (S)
Treating Clays:
Treating clay from clay filtering (S)
Treating clay from lube oil processing (S)
Treating clay from the extraction/isomerization process (S)
Treating clay from alkylation (S)
Miscellaneous Residuals:
Spent caustic from liquid treating (L)
Off-spec treating solution from sulfur complex and H2S removal facilities (S)
Acid-soluble oil from HF alkylation (S)
L: Requires listing determination as per the EDF/EPA consent decree.
S: Requires study as per the EDF/EPA consent decree.
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n. Industry Overview
A. Petroleum Refining Industry Profile
In 1992, the U.S. petroleum refining industry consisted of 185 refineries owned by 91
corporations. Refineries can be classified in terms of size and complexity of operations. Forty-
four percent of the refineries process less than 50,000 barrels per day of crude, while the 20
largest companies account for 56 percent of the nation's total refining capacity.
The simplest refineries use distillation to separate gasoline or lube oil fractions from crude,
leaving the further refining of their residuum to other refineries or for use in asphalt.
Approximately 18 percent of the U.S.'s refineries are these simple topping, asphalt, or lube oil
refineries. More sophisticated refineries will have thermal and/or catalytic cracking capabilities,
allowing them to extract a greater fraction of gasoline blending stocks from their crude. The
largest refineries are often integrated with chemical plants, and utilize the full range of catalytic
cracking, hydroprocessing, alkylation and thermal processes to optimize their crude utilization.
The refining industry has undergone significant restructuring over the past 15 years.
While the total national refining capacity dropped 17 percent since 1980 to 15 million barrels per
day, the number of refineries dropped 45 percent from 311 in 1980 to approximately 171 active in
1992. Refinery utilization rates over the 1980 to 1992 period rose from 75 percent to 90 percent.
Very few new refineries have been constructed in the past decade; the industry instead tends to
focus on expansions of existing plants.
The facilities closed tended to be smaller, inefficient refineries. Larger existing facilities
with capacities over 100,000 bbl/day have increased production to off-set the facility closings.
The data presented above indicates that the petroleum refining industry has been going
through a consolidation, which has resulted in a large decrease in the number of refineries in the
United States, but only a slight decrease in production. It is expected that this trend will continue,
with refineries continuing to close, but expansions occurring at others, keeping the total refinery
capacity in line with demand for refinery products.
In addition to restructuring, the industry is adding and changing production operations.
Although atmospheric and vacuum distillation, catalytic cracking, and their associated treating and
reforming operations will remain the primary refinery operations, new production operations
continue to be added. These include coking and desulfurization processes.
Many of these process changes are being implemented as a result of two factors: (1)
today's crudes tend to be heavier and contain higher levels of sulfur and metals, requiring process
modifications, and (2) a series of important pollution control regulations have been implemented,
including new gasoline reformulation rules designed to reduce the amount of volatile components
in gasoline, and new regulations requiring low-sulfur diesel fuels. These heavier crudes and new
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rules are causing refineries to make process modifications to their catalytic cracker units, as well
as installing additional sulfur removal hydrotreaters and unit processes to manufacture additives.
B. Process Descriptions
Refineries in the United States vary in size and complexity and are generally geared to a
particular crude slate and, to a certain degree, reflect the demand for specific products in the
general vicinity of the refinery. Figure II. 1 depicts a hypothetical refinery that employs the major,
classic unit operations used in the refinery industry. These unit operations are described briefly
below.
Storage Facilities: Large storage capacities are needed for feed and products. Sediments
can accumulate in these storage units. The consent decree identifies sediments (sludges) from the
storage of crude oil, clarified slurry oil, and unleaded gasoline for consideration as listed wastes.
Residual oil storage tank sediments were identified as a study residual.
Crude Desalting: Clay, salt, and other suspended solids must be removed from the crude
prior to distillation to prevent corrosion and deposits. These materials are removed by water
washing and electrostatic separation. Desalting sludge is a study residual.
Distillation: After being desalted, the crude is subjected to atmospheric distillation,
separating the crude by boiling point into light ends, naphtha, middle distillate (light and heavy gas
oil), and a bottoms fraction. The bottoms fraction is frequently subjected to further distillation
under vacuum to increase gas oil yield. No residuals from distillation are under investigation.
Catalytic Cracking: Catalytic cracking converts heavy distillate to compounds with
lower boiling points (e.g., naphthas), which are fractionated. Cracking is typically conducted in a
fluidized bed reactor with a regenerator to continuously reactivate the catalyst. Cracking catalysts
are typically zeolites. The flue gas from the regenerator typically passes through dry or wet fines
removal equipment prior to being released to the atmosphere. Catalyst and fines, as well as
sediments from storage of clarified slurry oil (the bottoms fraction from catalytic cracking), are
listing residuals of concern.
Hydroprocessing: Hydroprocessing includes (1) hydrotreating and hydrorefining (or
hydrodesulfurization), which improve the quality of various products (e.g., by removing sulfur,
nitrogen, oxygen, metals, and waxes and by converting olefins to saturated compounds); and (2)
hydrocracking, which cracks heavy materials, creating lower-boiling, more valuable products.
Hydrotreating is typically less severe than hydrorefining and is applied to lighter cuts. Hydro-
cracking is a more severe operation than hydrorefining, using higher temperature and longer
contact time, resulting in significant reduction in feed molecular size. Hydroprocessing catalysts
are typically some combination of nickel, molybdenum, and cobalt. Typical applications of
hydroprocessing include treating distillate to produce low-sulfur diesel fuel, treating naphtha
reformer feed to remove catalyst poisons, and treating catalytic cracking unit feed to reduce
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catalyst deactivation. Hydrotreating and hydrorefining catalysts are listing residuals, while
hydrocracking catalyst is a study residual.
Thermal Processes: Thermal cracking uses the application of heat to reduce high-boiling
compounds to lower-boiling products. Delayed (batch) or fluid (continuous) coking is essentially
high-severity thermal cracking and is used on very heavy residuum (e.g., vacuum bottoms) to
obtain lower-boiling cracked products. (Residuum feeds are not amenable to catalytic processes
because of fouling and deactivation.) Products are olefinic and include gas, naphtha, gas oils, and
coke. Visbreaking is also thermal cracking; its purpose is to decrease the viscosity of heavy fuel
oil so that it can be atomized and burned at lower temperatures than would otherwise be
necessary. Other processes conducting thermal cracking also would be designated as thermal
processes. Off-spec product and fines is a listing category from these processes.
Catalytic Reforming: Straight run naphtha is upgraded via reforming to improve octane
for use as motor gasoline. Reforming reactions consist of (1) dehydrogenation of cycloparaffins
to form aromatics and (2) cyclization and dehydrogenation of straight chain aliphatics to form
aromatics. Feeds are hydrotreated to prevent catalyst poisoning. Operations may be
semiregenerative, cyclic, or, less frequently, fully-regenerative, continuous, or moving bed catalyst
systems. Precious metal catalysts are used in this process. Spent reforming catalyst is a listing
residual.
Polymerization: Polymerization units convert olefms (e.g., propylene) into higher octane
polymers. Two principal types of polymerization units include fixed-bed reactors, which typically
use solid-supported phosphoric acid as the catalyst, and Dimersolฎ units, which typically use
liquid organometallic compounds as the catalyst. Spent polymerization catalyst is a study
residual.
Alkylation: Olefms of 3 to 5 carbon atoms (e.g., from catalytic cracking and coking)
react with isobutane (e.g., from catalytic cracking) to give high octane products. Sulfuric
(H2SO4) or hydrofluoric (HF) acid act as catalysts. Spent sulfuric acid, sulfuric acid alkylation
sludges, and HF sludges are listing residuals, while spent HF acid, acid soluble oil and treating
clays are study residuals.
Isomerization: Isomerization converts straight chain paraffins in gasoline stocks into
higher octane isomers. Isomer and normal paraffins are separated; normal paraffins are then
catalytically isomerized. Precious metal catalysts are used in this process. Spent catalysts and
treating clays are study residuals from this process.
Extraction: Extraction is a separation process using differences in solubility to separate,
or extract, a specific group of compounds. A common application of extraction is the separation
of benzene from reformate. Treating clay is a study residual from this process.
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Lube Oil Processing: Vacuum distillates are treated and refined to produce a variety of
lubricants. Wax, aromatics, and asphalts are removed by unit operations such as solvent extrac-
tion and hydroprocessing; clay may also be used. Various additives are used to meet product
specifications for thermal stability, oxidation resistances, viscosity, pour point, etc. Treating clay
is a study residual from this process.
Residual Upgrading: Vacuum tower distillation bottoms and other residuum feeds can
be upgraded to higher value products such as higher grade asphalt or feed to catalytic cracking
processes. Residual upgrading includes processes where asphalt components are separated from
gas oil components by the use of a solvent. It also includes processes where the asphalt value of
the residuum is upgraded (e.g., by oxidation) prior to sale. Off-spec product and fines, as well as
process sludges, are study residuals from this category.
Blending and Treating: Various petroleum components and additives are blended to
different product (e.g., gasoline) specifications. Clay and caustic may be used to remove sulfur,
improve color, and improve other product qualities. Spent caustic is a listing residual, while
treating clay is a study residual.
Sulfur Recovery: Some types of crude typically contain high levels of sulfur, which must
be removed at various points of the refining process. Sulfur compounds are converted to H2S and
are removed by amine scrubbing. The H2S typically is converted to pure sulfur in a Claus plant.
Off-gases from the Claus plant typically are subject to tail gas treating in a SCOTฎ unit for
additional sulfur recovery. Process sludges and spent catalysts are listing residuals; off-spec
product and off-spec treating solutions are study residuals.
Light Ends (Vapor) Recovery: Valuable light ends from various processes are
recovered and separated. Fractionation can produce light olefins and isobutane for alkylation, n-
butane for gasoline, and propane for liquid petroleum gas (LPG). No residuals from this process
are under investigation for either the listing determination or the study.
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Figure ILL Petroleum Refining Simplified Process Flow Diagram
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HI. Residual Descriptions and Source Reduction Practices for Residuals of Concern
Crude Oil Tank Sediment
Residual Description
Crude oil is stored prior to processing in an atmospheric distillation tower. It is necessary
to inventory crude oil to insure a steady supply. Tank sediments are emulsions that form from
solid particles, heavy oil, and water that settle to the bottom of tanks over time. Periodically the
tanks are emptied and the sediments removed. Cleaning is performed to either inspect the tank,
repair it, and/or remove excess quantities of sediments which build up and interfere with the tank
operation.
Hazardous constituents potentially present in crude oil tank sediments are identical to
those found in crude oil. They include benzene, toluene, ethylbenzene, and xylene (BTEX), sulfur
(including H2S), polynuclear aromatic hydrocarbons (PAHs), and metals.
Source Reduction Practices
Based on results from Section V of the survey, over 80 percent of facilities reporting tank
cleanings since 1991 used some type of in situ treatment procedure prior to removing the
sediments. This treatment most often consisted of washing the tank with hydrocarbon (e.g.,
naphtha) or water. The liquid captures organic compounds in the sediments; the liquid is typically
recycled to the crude unit via the recovered oil system. Note that additional facilities may perform
similar procedures outside of the tank which are not reported as in situ treatment.
Additional source reduction strategies which have been employed include the following:
Use of mixers to decrease sediments generation: Many facilities use permanent
mixers in their crude tanks to deliver homogenous feed to the crude unit. These
mixers also serve the function of entraining particulates and heavy hydrocarbon,
which would result as tank sediments, into the crude unit feed. Over 65 percent of
crude tanks were report to have mixers.
100 percent onsite recycling of sediments in process units: Observations from site
visits showed that 100 percent recycling of tank bottoms is being achieved at a
small number of sites. These facilities remove sediments from the tank and use it
as feedstock in another onsite unit. Factors influencing the practicality of this
technique have not been investigated, but probably depend on the types of
available process unit and crude type. The industry, as a whole, recycled about 44
percent of the tank sediment was reported to be recycled to the onsite coker,
distillation unit, catalytic cracker, or asphalt production unit.
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Increased efficiency of washing steps: One facility has attempted to increase the
amount of oil recovered from crude oil tank sediments by experimenting with
different surfactants and wash procedures. Such efforts reduce the volume of
sediments generated for disposal.
Control of spills: Several facilities install some type of sheeting near tank openings
to collect spills. Spilled sediment is recovered from the basin and re-incorporated
with the rest of the sediment. Spill reduction decreases the quantity of
contaminated soil to be disposed with the tank sediment.
The prevalence of these techniques are presented in Table III-l. This information is based on
1992 RCRA ง3007 Survey data.
Table ffi-l. Volume Reduction Methods Used for Crude Oil Tank Sediment
Volume Reduction Method
Filtration, Centrifuging, Dewatering
Emulsion Break, Melting
Settling
Water Wash
TOTAL
Number
of Streams1
48
6
9
1
64 (23%
of total streams)
1 The number of streams and percentage do not directly correlate to the total
number of streams presented in Table IV-4 due to multiple volume reduction
methods may be performed on a single stream.
Source: Section VI of RCRA ง3007 Survey.
Unleaded Gasoline Tank Sediment
Residual Description
Finished gasoline is blended from many refinery streams such as alkylate, reformate, and
straight run naphtha. Additives such as oxygenates are also added during blending. The finished
gasoline is stored in tanks prior to sale. Periodically, the tanks are emptied, cleaned, and
inspected.
The tank bottoms, sediments, or "sludge," are unlike the heavy hydrocarbon sludges that
typify crude oil tank sediments. Rather, small amounts of rust and scale are removed from the
tank bottom. Hazardous constituents present in gasoline will also be present in the tank bottoms;
these include BTEX.
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Source Reduction Practices
Most, if not all, of the refineries visited by SAIC and EPA wash the tank prior to entry and
sludge removal to remove the high level of airborne hydrocarbons present in the tank atmosphere
which could create both explosion and toxicity hazards (e.g., benzene) if not removed. Based on
the Survey, over 85 percent of the facilities cleaning a tank since 1991 reported washing, most
often with water. The liquid captures organic compounds in the tank bottoms; hydrocarbons in
the liquid are typically recycled to the crude unit via the facility sewer. Many facilities do not
generate a sludge from cleaning; the entire volume is treated in the refinery wastewater treatment
system.
Other than washing the tank bottoms, no other pollution prevention strategies are
identified. Table III-2 summarizes the prevalence of waste minimization activities from the
survey.
Table III-2. Volume Reduction Methods Used for Unleaded Tank Sediment
Volume Reduction Method
Filtration, Centrifuging, Dewatering
Settling
Water Wash
TOTAL
Number of Streams1
7
3
11
21 (8%
of total streams)
1 The number of streams and percentage do not directly correlate to the total
number of streams presented in Table IV-4 due to multiple volume reduction
methods may be performed on a single stream.
Source: Section VI of RCRA ง3007 Survey.
Residual Oil Tank Sediment
Residual Description
Residual oil is generally considered to be equivalent to No. 6 fuel oil and is typically
produced from units such as atmospheric and vacuum distillation, hydrocracking, delayed coking,
and visbreaking. Residual oil tank sediment (or sludge) consists of heavy hydrocarbons, rust and
scale from process pipes and reactors, and entrapped oil that settles to the bottom of the tank.
Hazardous constituents potentially present in residual oil tank sludge are similar to those
found in crude oil tank sludge. They include BTEX, sulfur (including H2S), PAHs, and metals.
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Source Reduction Practices
In many respects, the procedures for cleaning residual oil tanks are similar to those used
for cleaning crude tanks. The sludge is a mixture of heavy hydrocarbons which may be partially
recovered using an organic or surfactant wash, similarly to the cleaning of a crude tank.
Pollution prevention strategies which have been employed, or could be employed, include
the following:
Solids reduction in storage tank
Use as feedstock in process units
Table III-3. Volume Reduction Methods Used for Residual Oil Tank Sediment
Volume Reduction Method
Filtration, CentrifUging, Dewatering
Distillate Wash
Settling
Thermal Emulsion Break
Phase Separation
TOTAL
Number
of Streams1
19
3
2
1
1
26 (32%
of total streams)
1 The number of streams and percentage do not directly correlate to the total
number of streams presented in Table IV-4 due to multiple volume reduction
methods may be performed on a single stream.
Source: Section VI of RCRA ง3007 Survey.
1, Solids Reduction in Storage Tank
Use of mixers to decrease sludge generation: Many facilities use permanent mixers in
their tanks to deliver homogenous product. These mixers also serve the function of entraining
particulates and heavy hydrocarbon, which would result as tank sludge. About 50 percent of the
tanks were reported to have mixers.
2. Recycling
Upon cleaning a residual oil storage tank, sixteen facilities remove the sludge and recycles
it to either the onsite coker, distillation unit, catalytic cracker, or asphalt production unit. Table
III-3 summarizes the prevalence of waste minimization activities from the survey.
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CSO Sediment and/or Filter Solids
Residual Description
The bottoms stream from a fractionator of a catalytic cracker is called slurry oil or
clarified slurry oil (CSO). This material is typically sent directly to a storage tank for sale
(cartridge filters are occasionally used to remove particulates, such as FCC fines, from the
incoming feed). It may also be blended with other heavy refinery products. CSO sediments
and/or filter solids (sludge) can be generated from the intermittent cleaning of CSO storage tanks.
Periodically the tanks are emptied and the sludge removed. Cleaning is performed to either
inspect the tank, repair it, and/or remove excess quantities of sludge which build up and interfere
with the tank operation. According to the survey, they undergo in situ treatment less frequently
than crude or gasoline tanks (approximately 55 percent of facilities cleaning a CSO tank since
1991 report in situ treatment).
Hazardous constituents potentially present in CSO tank sludge are similar to those found
in crude oil tank sediments. They include BTEX, sulfur (including H2S), PAHs, and metals. In
addition, FCC catalyst will be present in the CSO. This solid will settle out in the tanks and add
significantly to the sludge volume.
Source Reduction Practices
In many respects, the procedures for cleaning CSO tanks are similar to those used for
cleaning crude tanks. The sludge is a mixture of heavy hydrocarbons which may be partially
recovered using an organic or surfactant wash, similarly to the cleaning of a crude tank.
Pollution prevention strategies which have been employed, or could be employed, include
the following:
Solids reduction of storage tank influent
Use as feedstock in process units
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1. Solids Reduction in Storage Tank Influent
Of the 117 refineries that have catalytic crackers, approximately half use a hydroclone,
slurry settler, or similar device to remove the solids (catalyst fines) in the slurry oil. These devices
can remove 80+ percent of the solids, which are recycled back to the FCC. The "clarified" slurry
oil is sent to tankage. Although this practice may lower sludge generation in product CSO tanks,
one refinery has stated that this practice lowers the efficiency of the FCC because the recycle
stream is heavier, and more difficult to crack, than the gas oil feed.
Newer FCC units have higher efficiency cyclones; at least one other refinery has modified
its FCC to incorporate new cyclones. The cyclones should minimize the amount of fines that
escape from the reactor with the overhead product and eventually leave the unit entrained in the
decant oil.
2. Recycling
Upon cleaning a CSO storage tank, one facility removes the sludge and recycles it onsite
in a coker. Table III-3 summarizes the prevalence of waste minimization activities from the
survey. Recovered hydrocarbons were reported to be recycled to the catalytic cracker, coker, or
asphalt production unit.
Table HI~4. Volume Reduction Methods Used for CSO Sediments and/or Filter Solids
Volume Reduction Method
Filtration, Centrifuging, Dewatering
Emulsion Break
Distillate Wash
TOTAL
Number of Streams1
24
3
1
28 (24% of total streams)
1 The number of streams and percentage do not directly correlate to the total
number of streams presented in Table IV-4 due to multiple volume reduction
methods may be performed on a single stream.
Source: Section VI of RCRA ง3007 Survey.
Desalting Sludge
Residual Description
Crude oil removed from the ground is contaminated with a variety of substances, including
gases, water, and various minerals (dirt). Crude oil desalting is a water-washing operation prior
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to atmospheric distillation which achieves additional crude oil cleanup. Water washing removes
much of the water-soluble minerals and suspended solids from the crude. If these contaminants
were not removed, they would cause a variety of operating problems throughout the refinery
including the blockage of equipment, the corrosion of equipment, and the deactivation of
catalysts.
Hazardous constituents potentially present in desalting sludge are benzene and PAHs.
Source Reduction Practices
As with some tank sediments, some facilities remove their desalting sludge using a vacuum
truck or similar slurrying device, then centrifuge the material and store the solids in a drum or
dumpster. Such procedures would explain the apparent discrepancy between the number of
streams removed as solid and the number of streams stored in containers (presumably also as
solid). Survey data indicate that approximately 10 percent of the streams generated in 1992
underwent dewatering or a similar volume reduction procedure.
Other source reduction techniques include: use of chemical demulsifiers and electrostatic
precipitation can decrease the amount of desalting sludge generated; shear mixing used to mix
desalter wash water and crude; turbulence avoided by using lower pressure water to prevent
emulsion formation; and alternative processes such as single-stage filtration.
Catalytic Cracking Catalyst and Fines
Residual Description
Fluid catalytic cracking is by far the most prevalent catalytic cracking process. In this
process, catalyst and gas oil feed are contacted in a fluidized bed. Cracked, lower molecular
weight hydrocarbon product is discharged at the top of the unit, after passing through cyclones to
separate the reactor catalyst. This product is fractionated. The reactor catalyst is continuously
regenerated in a parallel vessel. Flue gas from the regenerator contains some catalyst fines, which
can be removed by control devices including electrostatic precipitators and wet scrubbers. To
maintain activity, regenerated (equilibrium) catalyst is almost continuously removed and fresh
catalyst injected into the system. FCC catalyst is deactivated by various chemical compounds,
such as coke and metals. Coke is removed in the unit's regeneration cycle, but metals are not.
Source Reduction Practices
As with CSO sludge, higher efficiency cyclones will decrease the amount of catalyst
entrained in the cracked product. This, in turn, will decrease the quantity of fines in the flue gas
to be captured by an air pollution control device (ESP or scrubber).
Hydrotreating/Hydrorefining/Hydrocracking Catalyst
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Residual Description
Hydrotreating, hydrorefining, and hydrocracking are used to remove sulfur, nitrogen, and
metals and to saturate olefins and aromatics. Hydrocracking and hydrorefining, also used for mild
to extreme hydrocarbon cracking. They are used to protect downstream operations (such as
reforming) or to meet product specifications (such as low sulfur diesel). The catalysts are most
often some combination of cobalt, nickel, and molybdenum and in rare occasions tungsten.
Hazardous constituents include the base materials (i.e., cobalt, nickel, molybdenum, and
aluminum), hydrogen sulfide, and other metals or organics present in the hydrocarbon feed.
Source Reduction Practices
Catalyst loses activity as the active sites become either deactivated due to chemical
reaction with feed impurities or blocked due to coke precipitation on the catalyst surface.
Catalyst can be regenerated in situ (e.g., oxygen burn), and must periodically be replaced (in
whole or in part) with fresh catalyst during reactor shutdown.
Pollution prevention strategies which have been employed, or could be employed, include
the following:
Catalyst reuse: one facility regenerates their hydrotreating catalyst offsite for
onsite reuse. Catalyst is often reused in another onsite hydrotreater or
hydrorefiner which requires a lower activity.
Increasing catalyst life: silica is often present in naphtha from the coker.
However, silica is a hydrotreating catalyst poison and the naphtha is often
hydrotreated. One facility is experimenting with a process change to reduce the
quantity of silica in this stream, and hence extend the life of the hydrotreating
catalyst. Research activities are constantly working on extending catalyst's life
either by developing new catalyst or through the use of contaminant inhibitors.
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Table IDE-5. Volume Reduction Methods Used for
Hydrotreating/Hydrorefining/Hydrocracking Catalyst
Volume Reduction Method
Screening
TOTAL
Number of Streams1
12
12 (6% of total streams)
1 The number of streams and percentage do not directly correlate to the total
number of streams presented in Table IV-4 due to multiple volume reduction
methods may be performed on a single stream.
Source: Section VI of RCRA ง3007 Survey.
Reforming Catalyst
Residual Description
The purpose of reforming is to rearrange and dehydrogenate the feed stream to produce
high octane gasoline and petrochemical feedstocks (e.g., benzene). The dehydrogenation reaction
is strongly endothermic so units have multiple fixed bed reactors with heater passes in between.
The catalyst is typically platinum chloride on alumina.
The catalyst is regenerated in situ, reused, and only replaced when regeneration is no
longer effective due to catalyst poisoning (poisons include coke, sulfur, and some metals). The
frequency of regeneration is specific to unit design and can range from continuously to once per
year. Regeneration procedures typically include a coke burn, reactivation using a chlorine-
containing compound, and occasionally a passivation step using a sulfur containing compound.
Hazardous constituents present in the spent reforming catalyst may include feed and
product hydrocarbon (e.g., benzene).
Source Reduction Practices
Source reduction strategies which have been employed, or could be employed, include
optimizing the feed and operating parameters. Refineries with multiple reforming units will often
adjust the feed to the particular needs of each unit. One refinery claims that by operating one
such unit with optimal feeds the life of the catalyst charge is prolonged. However, it is not known
if catalyst life on the one unit is prolonged at the expense of the other.
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Table IH-6. Volume Reduction Methods Used for Reforming Catalyst
Volume Reduction Method
Screening
TOTAL
Number of Streams1
2
2 (2% of total
streams)
1 The number of streams and percentage do not directly correlate to the total
number of streams presented in Table IV-4 due to multiple volume reduction
methods may be performed on a single stream.
Source: Section VI of RCRA ง3007 Survey.
Catalyst from Isomerization
Residual Description
The purpose of isomerization is to increase the refinery's production of high octane, low
aromatic gasoline. Principal applications of isomerization at refineries are naphtha isomerization.,
which produces a gasoline blending component, and butane isomerization, which produces
isobutane feed for the alkylation unit.
The most prevalent catalyst used for both butane and naphtha isomerization is platinum or
platinum chloride on alumina or zeolite. When the catalyst loses activity, it is removed from the
reactor and replaced with fresh catalyst.
Hazardous constituents present in the spent isomerization catalyst may include
hydrocarbons such as benzene.
Source Reduction Practices
Source reduction strategies which have been employed, or could be employed, include
optimizing the feed and operating parameters. Removing catalyst contaminants from the feed,
such as H2S and water, prior to introduction into the reactor can increase catalyst life.
Due to the precious metal make-up of the catalyst, almost all of it is recycled for metals
reclamation.
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Treating Clay from Isomerization/Extraction
Residual Description
The purpose of isomerization is to increase the refinery's production of high octane, low
aromatic gasoline. Principal applications of isomerization at refineries are naphtha isomerization,
which produces a gasoline blending component, and butane isomerization, which produces
isobutane feed for the alkylation unit. Not all facilities with isomerization units use
"treating clay," or adsorbents. However, solid adsorbents can be used in three places in the
isomerization process:
Hydrocarbon feed purification. Processes using platinum chloride catalysts
require a purified feed. Both spent molecular sieve (for drying) and spent metal-
alumina (for sulfur removal) are generated.
Hydrogen feed purification. Processes using platinum chloride catalysts require
dry hydrogen gas. Spent molecular sieve is generated.
Paraffin separation of the feed or product. Various types of processes use
adsorbents for paraffin separation. Molecular sieve is the most common adsorbent
for this application.
Extraction processes separate more valuable chemical mixtures from a mixed aromatic and
paraffinic stream. At refineries, extraction processes most commonly fall into two types: (1)
"heavy end" extraction, commonly used in lube oil manufacture and deasphalting operations to
upgrade and further process gas oils, and (2) gasoline component extraction, commonly used to
separate some of the more valuable aromatics from naphtha. Treating clay is used to remove
impurities from the hydrocarbon following extraction; the most common application is the
filtering of the aromatic fraction prior to benzene distillation (likely to keep impurities out of the
downstream fractions), although a small number of facilities use the clay to filter the benzene
product stream only. The purpose of the clay is to remove olefins, suspended solids, and trace
amount of solvent by a combination of adsorption and catalytic processes.
All of these adsorbents go through adsorption/desorption cycles. Over time, the adsorbent
loses its capacity or efficiency and is removed from the vessel and replaced with fresh adsorbent.
Hazardous constituents contained in the treating clay are hydrocarbons such as benzene.
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Source Reduction Practices
Treating clay for isomerization and extraction are generally used as a method of
prolonging the life of the catalyst or as product polishing. Because they are used as a source
reduction technique for other residuals, no source reduction methods for the clays were found.
Sulfimc Acid Alkylation Sludge and Catalyst
Residual Description
In the sulfuric acid (H2SO4) alkylation process, olefin and isobutane are contacted over
concentrated liquid sulfuric acid in a reactor to generate high-octane alkylates for gasoline
blending. The product is separated and neutralized and the separated acid is returned to the start
of the process.
Acid requires periodic or continuous purging and replacement to minimize impurity levels
and to maintain adequate acid strength. The spent acid is stored for subsequent shipment off-site
for regeneration.
There are at least two sources of sludge in this process: sludge from process waters (e.g.,
caustic washwater) and sludge from unit operations (e.g., tanks, reactors).
Hazardous constituents in the spent sulfuric acid is, of course, sulfuric acid. Other
constituents include hydrocarbons. In the sludge, hazardous constituents include hydrocarbons.
The acid is neutralized and is not a hazard.
Source Reduction Practices
Source reduction strategies which have been employed, or could be employed, include the
following:
Decreasing oil content of spent sulfuric acid
New alkylation process
Use of soluble neutralizing agents
1. Decreasing Oil Content of Spent Sulfuric Acid
One refinery has adopted a procedure designed to minimize the amount of hydrocarbons
entrained in the spent sulfuric acid. The facility mixes alkylation fractionation section bottoms
(i.e., alkylate product) with the acid discharge from the primary settler. The heavy hydrocarbons
absorb light hydrocarbons and carry them to the hydrocarbon layer in the secondary settler. This
procedure significantly reduces the amount of butane and lighter hydrocarbons entrained in the
spent acid. Rather than becoming part of the spent sulfuric acid residual stream or vented to the
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refinery flare, the light hydrocarbons become alky butane or fuel gas. This practice was designed
to reduce the danger of having hydrocarbons in the vapor space of the spent sulfuric acid tanks.
2. New Alkylation Process1
New processes using solid catalyst and small amounts of liquid catalyst would not
generate neutralization sludges the same way as present H2SO4 alkylation units. This is still a
preliminary process under development. In addition, the large quantities of spent liquid catalyst
presently produced would not be generated in the new process.
3. Decreasing Sludge Generation
Refiners have decreased sludge generation by switching from insoluble neutralizing agents
(e.g., lime) to soluble agents (sodium hydroxide).
HF Alkylation Catalyst and Sludge
Residual Description
Olefin and isobutane gases are contacted over concentrated liquid hydrofluoric (HF) acid
in a reactor to generate high-octane alkylate for gasoline blending. The product is separated into
alkylate and lighter fractions and neutralized; the HF acid is returned to the start of the process.
A portion of the acid recycle stream is continuously distilled to generate purified HF acid (as
overhead) and heavy hydrocarbon/azeotrope as bottoms. The bottoms, along with neutralization
waters from product treatment, are commonly discharged to an neutralization pit. Sludge,
consisting of neutralization compounds and organics, commonly forms in the tank and requires
periodic removal.
Hazardous constituents in the acid is the HF acid. Hazardous constituents in the sludge
includes oil. The sludge is neutralized and no longer contains hydrofluoric acid.
Source Reduction Practices
Source reduction strategies for the sludge and catalyst which have been employed, or
could be employed, include the following:
Segregation of oil from sludge (sludge)
Raw material substitution (sludge)
New Alkylation Process (sludge and catalyst)
Solid catalyst alkylation processes are currently in the pilot plant stages but the Oil and Gas Journal reported
that they would be commercially available as early as the end of 1995.
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1. Segregation of Oil
Many refineries discharge regenerator bottoms (which includes oil) is discharged to the
neutralization pit. However, many other refineries do not and reuse the oil in another part of the
refinery. When discharged to the pit, the oil typically becomes part of a sludge removed for
disposal.
2. Raw Material Substitution
Changing the neutralization agent used in the pit can affect management options for the
generated sludge. Neutralization agents commonly include sodium hydroxide, calcium hydroxide
(lime), or potassium hydroxide. Its purpose is to neutralize and remove fluorides from the
alkylation plant wastewaters prior to being released to the sewer.
Some refineries have switched from neutralizing with lime which generates an insoluble
salts to sodium hydroxide which is soluble. However, this may cause problems at the wastewater
treatment plant in meeting NPDES permit levels for fluoride.
Several facilities use neutralizing agents which precipitate the fluoride compounds and
produce a marketable product (e.g., calcium fluoride). A small number of refineries do not
generate a fluoride sludge at all and discharge the HF alkylation plant effluent to its wastewater
treatment plant. However, this may cause problems at the wastewater treatment plant in meeting
NPDES permit levels for fluoride.
3. New Alkylation Process
New processes using solid catalyst and small amounts of liquid catalyst would not
generate neutralization sludges the same way as present HF alkylation units. This is still a
preliminary process under development.
Additional source reduction is not possible for the catalyst because of the closed loop
recycle process and the strict controls placed on this material due to the severe health hazards
associated with contact and inhalation.
Add Soluble Oil (ASO)from HF Alkylation
Residual Description
A residual of high molecular-weight reaction by-products dissolves in the HF acid catalyst
and lowers its effectiveness. To maintain the catalyst activity, a slip stream of catalyst is distilled,
leaving the by-product, acid soluble oil (ASO), as a residue. The ASO is charged to a decanting
vessel where an aqueous phase settles out. The ASO is scrubbed with potassium hydroxide
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(KOH) to remove trace amounts of HF and either recycled, sold as product (e.g., residual fuel),
or burned in the unit's boiler.
Hazardous constituent possibly contained in the ASO include hydrocarbons and HF acid.
Twenty-five percent of the ASO was reported to be managed as characteristically hazardous.
Source Reduction Practices
As described in previous sections, several solid-acid catalysts used for alkylation are being
tested in pilot plants. The reactor systems are different from the current liquid-acid systems, but
for one system the other equipment is compatible. Three types of the new solid catalyst include
aluminum chloride, alumina/zirconium halide, and antimony pentafluoride (a slurry system). It is
likely that ASO will not be generated in a solid catalyst system.
Treating Clay from Alkylation
Residual Description
Treating clay from alkylation predominantly includes (1) molecular sieves used for drying
feed and (2) alumina used for removing fluorinated compounds from the product. Both are
applications in HF alkylation; clays are not used as frequently in sulfuric acid alkylation.
After fractionation, products may be passed through a filter filled with sorbents (referred
to as treating clay) to remove trace amounts of acid, caustic, or water. Sorbents typically used in
this service include alumina, molecular sieve, sand, and salt.
Source Reduction Practices
As discussed in the HF alkylation catalyst section, several solid-acid catalysts used for
alkylation are being tested in pilot plants. It is unclear whether these processes will generate more
or less treating clays than current processes. Theoretically, these processes would not require
filtering for acid and water removal.
Distillation to dry the feed to the HF acid alkylation unit has also been used. Most
facilities use a molecular sieve treating clay for this step, therefore this process configuration
eliminates the need for molecular sieve infrequently generating an RC.
Hazardous constituents contained in the treating clay are hydrocarbons such as volatile
organic compounds.
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Catalyst from Polymerization
Residual Description
Polymerization is a process utilized for the conversion of propane/propylene and/or
butane/butene feeds from other operations into a low molecular weight, higher-octane, polymer
product, referred to as dimate. Dimate is used as a high octane gasoline blending component of
unleaded gasolines. There are primarily two polymerization processes utilized by the petroleum
refining industry: phosphoric acid polymerization and the Dimersol process. Spent phosphoric
acid polymerization catalyst is generated after the solid catalyst active sites have become blocked
and lost their reactivity.
Dimersol catalyst is added to the reactor feed stream and exits the final reactor as part of
the reactor effluent. The liquid catalyst is then removed from the reactor effluent by
neutralization (contact with caustic). Spent caustic streams, containing the spent dimersol
catalyst, are commonly reused on-site or sent off-site for metals reclamation or caustic recovery,
and as a result are typically not solid wastes. Spent catalyst also may be generated in two other
points in the process. First, during routine shutdowns spent catalyst may be generated as a
component of any reactor sludge removed from the reactors. Second, certain Dimersol processes
contain filters following caustic neutralization and water washing to remove entrained residual
nickel from the dimate product. The filters are removed and disposed periodically.
Hazardous constituents possibly contained in the catalyst include phosphoric acid, metals,
and hydrocarbons.
Source Reduction Practices
No source reduction methods were reported by industry or found in the literature search.
Off-spec Sulfur, Sulfur Sludge, Spent Amine and Sulfur Catalyst
Residual Description
Sulfur-containing compounds are removed from petroleum as hydrogen sulfide at many
points in the refinery. The hydrogen sulfide is concentrated by absorption/desorption with an
aqueous solution, such as amine. Sulfur is most commonly recovered as elemental sulfur in Claus
units. Claus tail gas may be further treated to remove sulfur prior to being discharged to the
atmosphere. This is accomplished by passing the gas through a hydrotreating bed (to reduce the
sulfur dioxide to hydrogen sulfide) and absorbing the sulfur in a solution such as amine. Spent
catalyst is generated from the Claus reactors and the tail gas hydrotreating reactor. Sludge is
generated from the amine solutions. Like other refinery products, sulfur must meet certain
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customer specifications such as color and impurity levels. The failure of the refinery to meet these
requirements causes the sulfur to be "off-spec."
Source Reduction Practices for Sulfur Sludge
Source reduction strategies which have been employed for sulfur sludge, or could be
employed, include the following:
Use of alternative sulfur removal solutions: Many refineries use methyl diethanol
amine (MDEA) instead of monoethanol amine (MEA) at the tail gas unit. MDEA
is not as susceptible to the formation of heat stable salts and is amenable to
regeneration. Using MDEA greatly reduces the amount of amine sludge and spent
amine solution generated by the tail gas unit.
Additives to reduce heat stable salt formation: At least two facilities control heat-
stable salts in their MDEA amine treating system using a proprietary caustic.
Elimination of filters: Two facilities have replaced their cloth or cartridge filters
with an etched metal mechanical filter. The new filter requires less maintenance,
reduces the number of filter elements disposed of, and also eliminates amine
discharges to the WWTP due to filter change-outs.
Source Reduction Practices for Sulfur Catalyst
Source Reduction strategies which have been employed for sulfur catalyst, or could be
employed, include process redesign. Some processes, such as the Stretford process, do not use
solid catalyst. The catalyst is in a liquid state and is continuously reused. Stretford system have
limited use as both sulfur recovery units and tail gas units. Note that although the solid catalyst
stream is eliminated in the Stretford process, the possibility of the liquid catalyst being present in
other waste or residual streams was not investigated.
Source Reduction Practices for Off-spec Sulfur
During EPA's site visit, one facility was observed to generate "off-spec" sulfur product
daily. Portions of the sulfur plant are being replaced with a newer design. As a result, waste
sulfur residual from equipment "low points" will no longer be generated.
Source Reduction Practices for Spent Amine
Source reduction of amine involves modifying the process. During the site visits,
information was gathered that several facilities capture the amine for recycling. Two facilities
replaced the cloth filter at the sulfur recovery unit with an etched metal mechanical filter. The
new filter requires less maintenance, and also eliminates amine discharges to the wastewater
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treatment plant due to filter change-outs. Another two facilities have installed sumps at the sulfur
complex. The sumps capture amine that is drained from the filters during bag change-outs and
recycle it to the amine system. Without the sumps, the amine drained from the filters is
discharged to the wastewater treatment plant.
One facility described reducing amine entrainment in LPG through the installation of
coalescers. Amine was kept within the system, reducing raw material requirements for make-up.
Thermal Processing Fines and Off-Spec Product
Residual Description
Delayed coking units are the most common type of thermal treatment units, and the most
common type of unit to generate fines. Most refineries report that their thermal units do not
generate "off-spec" product; all of their coke product is typically salable.
A thermal process heats the charge oil to a temperature at which it will crack into lighter,
more valuable components. Unlike catalytic cracking processes, no catalyst is used. The cracked
product is fractionated. Coke gradually builds up within the vessel and is drilled out with a water
jet upon completion of the coking cycle. Coke, ranging in size from fines to large chunks, are
gravity dumped to a pad. Fines may settle on the pad, or be entrained with the washwater. Some
fines entrained in the water are settled. At most refineries, water is reused within the coking unit.
Coke fines entrained in the water, therefore, generally do not leave the unit limits.
Hazardous constituents potentially present in coke fines is coke, metals, and heavy organic
hydrocarbons.
Source Reduction Practices
Coke fines are viewed by many refineries to be part of the coke product since they are
often recombined with larger coke and sold. Therefore, the following are pollution prevention
strategies to keep coke fines out of waste streams:
Recovery of coke fines in water
Spill prevention
1. Recovery of Coke Fines in Water
Several years ago, one refinery initiated a program to keep coke fines from getting into the
process water sewer. By installing filters at sewer drains and keeping the coker battery limits
clean they have significantly reduced their volume of wastewater treatment (i.e., F037/F038)
waste.
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A water hydroclone is being built at one facility's delayed coking unit to capture coke fines
that escape from their fines collector. The fines recovered by the cyclone will be incorporated
into the coke and sold as product. If the fines are not captured by the cyclone, a portion of them
are discharged to the WWTP where they may combine with other process wastewaters and
generate hazardous waste in treatment and storage units.
2. Spill Prevention
Coke product may be spilled during loading onto railcars, product transfer, etc. Keeping
the coke handling area free of dirt eliminates the contamination of spilled coke product, which can
be stockpiled with the remaining coke product.
Off-specification Product and Process Sludge from Residual Upgrading
Residual Description
After vacuum distillation, there are still some valuable oils left in the vacuum-reduced
crude. Vacuum tower distillation bottoms and other residuum feeds can be upgraded to higher
value products such as higher grade asphalt or feed to catalytic cracking processes. Residual
upgrading includes processes where asphalt components are separated from gas oil components
by the use of a solvent. It also includes processes where the asphalt value of the residuum is
upgraded (e.g., by oxidation) prior to sale.
Off-spec product from residual upgrading includes material generated from asphalt
oxidation, solvent deasphalting, and other upgrading processes. Only one facility reported
generating this residual.
Process sludge is generated from miscellaneous parts of the various residual upgrading
processes. Solvent deasphalting may generate a sludge due to hydrocarbon carryover in the
solvent recovery system. Similarly, the ROSE process may generate sludges due to process
upsets in the solvent condensate collection system. Additional sludges may be generated during
unit turnarounds and in surge drums and condensate knockout drums.
Hazardous constituents for these residuals include PAHs.
Source Reduction Practices
Source reduction techniques were reported to be process modifications and better
housekeeping. This residual is generated infrequently and in very small quantities, therefore
limited information was expected.
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Spent Treating Clay from Lube Oil Filtering
Residual Description
Vacuum distillates are treated and refined to produce a variety of lubricants. Wax,
aromatics, and asphalts are removed by unit operations such as solvent extraction and
hydroprocessing; clay may also be used. The majority of treating clays (including other sorbents)
generated from lube oil processing are from acid-clay treating in refining or lube oil finishing.
Source Reduction Practices
This residual is generated infrequently and in very small quantities. Treating clays use for
product polishing in lube oil manufacturing is being phased out by industry. No source reduction
methods were reported by industry or found in the literature search.
Spent Caustic
Residual Description
Liquid treating operations are used to remove impurities (e.g., mercaptan sulfur, organic
acids) from product streams (e.g., gasoline) prior to sale. Treatment is accomplished by liquid-
liquid (or gas-liquid) contacting, followed by regeneration of the caustic treating solution. The
regeneration step may result in the generation of purge caustic, which is replaced by fresh make-
up.
Source Reduction Practices
Refineries may reuse spent caustic for other services (i.e., cascading the caustic).
One refinery has installed a hydrotreater to reduce the sulfur content of its diesel fuel
product, As a result, the caustic treating unit that was used to treat this product was eliminated
from service (thus eliminating the generated waste stream).
Spent Treating Clay from Clay Filtering
Residual Description
Clay belongs to a broad class of materials designed to remove impurities via adsorption.
Examples of clay include Fullers earth, natural clay, and acid treated clay. However, similar
materials such as bauxite are also available and used to impart similar qualities to the product. In
addition, materials such as sand, salt, molecular sieve, and activated carbon are used for removing
impurities by adsorption or other physical mechanisms.
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Generated at many places in the refinery, spent solid sorbents have liquid contents ranging
from very low (e.g., for molecular sieves treating light hydrocarbons) to oil-saturated material
(e.g., for clay used for treating kerosene). The substrate is either inorganic (such as alumina,
zeolite, or clay) or organic (such as activated carbon). Most applications are fixed bed, where the
material is charged to vessels and the hydrocarbon passed through the fixed bed of solid sorption
media. The fixed bed can remain in service for a period of time ranging from several months to
10 years, depending on the application. At the end of service, the vessel is opened, the "spent"
material removed, and the vessel recharged.
Source Reduction Practices
One facility reported that its jet fuel treating clay is regenerated once by back-washing the
clay bed with jet fuel to "fluff1 the clay and alleviate the pressure drop.
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IV. Review of Data Sources
As discussed in more detail later in this section, waste minimization information has been
compiled from the following sources for this report:
Various sections of the 1992 RCRA ง3007 Surveys (i.e., Sections V, VI, XI) for
all 185 refineries operating in 1992.
Twenty site visit reports, from refineries visited in 1993 for the listing
determination and industry study.
Relevant articles from the 1993 to 1996 issues of Hydrocarbon Processing and Oil
& Gas Journal, and relevant papers presented at the Fall 1994 National Petroleum
Refineries Association (NPRA) Environmental Conference.
Each of these sources provide different levels of detail for different numbers of facilities.
Examples of innovative source reduction and recycling techniques are available (as discussed later
in this report), but the following techniques are used on an industry-wide basis:
Tank Sediments (Crude, Unleaded, CSO, Residual Oil): Many refineries use filter
presses, centrifuges, or other onsite solids separation equipment to recover
hydrocarbons for recycle to the process. In-tank mixers also may be used to
decrease sludge accumulation.
Solid Catalysts (FCC, Hydrotreating, Hydrorefining, Hydrocracking, Reforming,
Isomerization, Polymerization, and Sulfur Complex): Where possible catalysts are
regenerated, reclaimed, and/or reused on and offsite, or the process optimized to
prolong catalyst use. However, ultimately catalysts must be periodically replaced
with fresh catalyst. Spent catalysts are often sent offsite for metals reclamation or
other reuse. In the case of reformer catalyst, commercial value is very high.
Sulfuric Acid Alkylation Catalyst and Spent Caustic from Liquid Treating:
Source reduction opportunities are low for these two high volume liquid streams.
Standard industry practice is to send spent sulfuric acid offsite for regeneration and
reuse as a feedstock or product substitute in downstream industries; many
refineries also send their spent caustics offsite for reuse. Hydrotreating may be
used to significantly lessen the amount of liquid treating that is needed.
Sludge from HF Alkylation: This residual is generated specifically for pollution
control purposes (i.e., to control fluoride levels in refinery effluent, and to mitigate
airborne releases of HF Acid). As a result, the residual cannot effectively be
"reduced" but many refineries are taking steps to beneficially reuse the sludge and
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reduce the disposed volume. This typically requires some effort in segregating oily
or low fluoride process water from relatively clean, high fluoride process water.
Sulfur Sludge: Most waste minimization efforts for this residual focus on source
reduction, as on- or offsite recycling is not practical. It is difficult to assess the
trend in source reduction for this residual, but some techniques include switching
amine systems (which reduces sludge generation) or the use of reusable solids
removal equipment (which reduces the quantity of support media, such as filters,
going to disposal). EPA realizes this is an expensive undertaking but has been or
is currently being done by a some refineries.
Coke Fines: Most refineries recombined their coke fines with their coke product
for sale. Refineries generally do not report source reduction methods for fines
because, as long as the fines can be recovered for incorporation into the product,
they are not of concern.
Sulfuric AcidAlkylation Sludge: Most refineries have switched from insoluble
neutralizing agents to soluble neutralizing agents to decrease sludge accumulation.
Treating Clays (Clay Filtering, Alkylation, Extraction/Isomerization, and Lube
Oil): Treating clays comprise of such a wide variety of material (clay, molecular
sieve, salt) and are used for a wide variety of services (defluorination, dewatering)
that waste minimization activities can vary greatly. In some cases, treating clay is
used as a waste reduction process for another waste (i.e., isomerization catalyst)
and, therefore, cannot be reduced.
ASO: With the development of solid acid catalysts, ASO may be eliminated.
Currently it is primarily recycled either as product or burned onsite for energy
recovery.
Off-specification Product (Sulfur complex and Residual Upgrading): Most
refineries recombined their off-spec product with their product for sale or send it
for reprocessing. Refineries generally do not report source reduction methods for
off-spec product because, as long as it can be recovered for incorporation into the
product or recycled back into the process, they are not of concern.
Residual Upgrading Sludge: Little or no waste minimization information is
available for this low volume residual.
Desalting Sludge: Waste minimization activities include dewatering, use of filters,
and low pressure flow to reduce turbulence and emulsion generation. Use of
waste minimization techniques in other parts of the refinery can increase desalting
sludge production (e.g., mixers in crude tanks).
Waste Minimization for
Petroleum Refineries
31
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HFAlkylation Catalyst: With the development of solid acid catalyst and the
hazardousness of HF acid, the industry may in the future be naturally moving away
from this residual.
Spent Amine: Spent amine is generally generated through process losses. By
increasing process efficiency, refineries could reduce raw material consumption.
Further detail on the sources used and a discussion on their usefulness is presented below.
A. RCRA ง3007 Survey Section XI
Source reduction information was explicitly requested in Section XI of the survey for all
residuals reported in the survey. This section included (1) the facility's past, existing, and future
activities to reducing residual volume and reducing toxicity, (2) detailed discussion of residuals
eliminated, and (3) discussion of regulatory barriers to source reduction. Approximately 90 of
1722 respondents completed item (1), 18 respondents completed item (2), and 21 respondents
completed item (3).
Tables IV-1 to IV-3 present source reduction information from Section XI of the survey.
Most responders provided this information as non-CBI; therefore most information from this part
of the survey could be presented here in detailed form. Table IV-1 summarizes ongoing facility-
specific source reduction activity for the residuals. The information presented in Table IV-1
reflects only what has been reported. Insufficient information was provided (or requested) to
determine what the specific source reduction practice is. In fact, for some refineries that did
provide additional information, their reported practices were not source reduction at all but were
rather more appropriately termed recycling. Given these limitations, this table shows that many
refineries practice source reduction/recycling for crude tank sludge, FCC catalyst and fines, and
spent caustic.
Table IV-2 summarizes all residuals reported to be eliminated since c. 1989 (both listing
and study RCs). No trends are evident from this table due to the low number of facilities
reporting on a broad range of residuals.
Table IV-3 summarizes the reported regulatory barriers to source reduction (both listing
and study RCs). Many of these refineries discuss regulatory barriers that would take place if the
RCs were further regulated; these concern permitting for treatment and barriers of transferring
hazardous wastes between refineries for recycling or recovery.
Only 172 of the 185 refineries completed and returned RCRA ง3007 Surveys, explanations to the less than 100 percent
response arc provided in the Petroleum Refining Listing Determination Background Document.
Waste Minimization for
Petroleum Refineries
32
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Section XI also requested information on toxicity reduction goals. Only two refineries
reported goals for hazardous constituents; both set goals for benzene (one facility for spent
caustic and another for hydrotreating/hydrorefming catalyst). Most other refineries provided
goals for classes of constituents, such as "oil," or nonhazardous constituents such as water.
B. RCRA ง3007 Survey Section VI
Section VI of the Survey contains management information such as on- and offsite
recycling, treatment, and final disposition. All 172 refineries completed this section. Table IV-4
summarizes the relevant waste minimization information found in response to this section for the
RCs. This table shows that recycling practices are widespread for the following RCs (i.e., about
80 percent of the industry practices some form of recycling):
Crude oil tank sludge, CSO, and residual oil tank sludge are recycled onsite to the
crude unit, or is pressure filtered or centrifuged.
FCC catalyst (not fines) is most often recycled offsite to cement kilns or to other
refineries.3
Hydrotreating, hydrorefming, hydrocracking, reforming, isomerization, and sulfur
plant tail gas catalyst are most often sent offsite for reclamation/regeneration.
Sulfuric acid alkylation catalyst is sent offsite to sulfuric acid producers to make
sulfuric acid.
Coke fines are mixed with the coke product and sold offsite.
Spent caustics are either recycled offsite for reuse, sold offsite for use as a raw
material, or used onsite in process equipment (e.g., wastewater treatment, desalter)
for its caustic qualities.
Oil-bearing secondary materials (e.g., crude oil tank sediment, desalting sludge,
etc.) are recycled to refinery process units (e.g., cokers, distillation unit, FCC unit,
etc.).
Information on Section V of the survey is presented in Section III of this report. Section
V of the survey contains useful information concerning in situ tank cleaning; this type of cleaning
is conducted to recover useful hydrocarbons from the tank bottoms prior to opening the tank.
API representatives stated that spent FCC catalyst is also used as inert construction material, however, this
reuse method was not reported in the ง3007 survey or conveyed by the refineries during the engineering site
visits.
Waste Minimization for
Petroleum Refineries
33
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C Site Visits
In 1993, the Agency conducted engineering site visits to 20 refineries. Waste
minimization activities applicable to the RCs were observed for every facility. Some were
common, such as offsite metals reclamation, and reflected the trends noted in Table IV-4. Others
were more innovative, such as the substitution of metal screens for cartridge filters in amine
systems. All of these ideas are summarized in Table IV-5.
D, Journal Articles
An in-house literature search was conducted by EPA and SAIC. Source reduction
activities documented in the industry trade journals Hydrocarbon Processing and Oil & Gas
Journal and conference proceedings were investigated.
Over 70 articles detailing waste minimization techniques for 20 RCs were found.
Additional articles detail waste minimization activities for other refinery residuals or are more
general in nature. All articles are summarized in Table IV-6.
Most of the articles concerning pollution prevention for catalysts discussed new catalyst
additives (such as traps to prevent poisoning) or process changes to give longer life to the
catalysts. Oil & Gas Journal highlighted future alkylation processes in one of its issues. Other
articles discuss practices observed from site visits, such as offsite metals reclamation and sludge
treatment for oil recovery. It is difficult to determine whether the ideas presented in these articles
are widespread or represent research by one facility.
Waste Minimization for
Petroleum Refineries
34
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Table IV-1. Summary of Pollution Prevention Information Available
from Section XI of Surveys
Residual of Concern
# of Sites Reporting
Source Reduction
Info/ # of Streams
Most Frequent
Source Reduction Practices
Detailed Source Reduction
Practices'
Listing Residuals
Crude Tank Sludge
Unleaded Gasoline Tank
Sludge
CSO Sludge
Catalytic Cracking
Catalyst and Fines
Hydrotreating and
Hydrorefining Catalysts
Reforming Catalyst
Sulfuric Acid Alkylation
Catalyst
Sulfuric Acid Alkylation
Sludge
Hydrofluoric Acid
Alkylation Sludge
Sludge from Sulfur
Removal
Catalyst from Sulfur
Complex
Fines and Off-spec
Product from Thermal
Processing
Spent Caustic
17/46
1/2
6/18
20/26
8/20
7/9
2/3
0
6/7
9/18
7/10
9/13
24/40
Equipment/ technology
modification; process/
procedure modifications
Equipment/ technology
modification; process/
procedure modifications
Equipment/ technology
modification
Equipment/ technology
modification; process/
procedure modifications
Process/ procedure
modifications
Equipment/ technology
modification; process/
procedure modifications
process/ procedure
modifications
Equipment/ technology
modification
Equipment/ technology
modification; process/
procedure modifications
process/ procedure
modifications
process/ procedure
modifications
process/ procedure
modifications
crude unit shutdown; recover
and reuse; using chemical
treatment prior to removal
Settler removes alumina from
CSO
Redesigned FCC cyclones
regeneration onsite;
regeneration and reuse
more time between change-out
modify drain to recover coke
fines from water
recycled to crude unit to
neutralize acid in crude; no
longer in operation;
construction of oxidizer
Waste Minimization for
Petroleum Refineries
35
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Table IV-l. Summary of Pollution Prevention Information Available
from Section XI of Surveys
Residual of Concern
# of Sites Reporting
Source Reduction
Info/ # of Streams
Most Frequent
Source Reduction Practices
Detailed Source Reduction
Practices'
Study Residuals
Isomerization Catalyst
Off-Specification Sulfur
Off-Specification
Treating Solution from
Sulfur Removal
Hydrocracking Catalyst
Desalter Sludge
Acid Soluble Oil
Alkylation Treating Clay
Treating Clay from Clay
Filtering
Process Sludge from
Residual Upgrading
6/6
6/6
9/16
4/5
21/32
11/14
4/4
11/14
2/2
Process/ procedure
modifications
Process/ procedure
modifications; improved
housekeeping
Equipment/ technology
modification
Process/ procedure
modifications
Equipment/ technology
modification; process/
procedure modifications
Equipment/ technology
modification
Process/ procedure
modifications; improved
training
Process/ procedure
modifications; substitution
of raw materials
Process/ procedure
modifications; improved
housekeeping
Minimize Stretford solution
carryover
Offsite regeneration or offsite
metals recovery
Unit shutdown
Press to recover KOH
1, Some responses provided a brief description of their activity. These responses are provided here.
Waste Minimization for
Petroleum Refineries
36
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Table IV-2. Detailed Residual Elimination Information Available
from Section XI of Surveys
Residual of Concern
Crude Tank Sludge
Unleaded Gasoline Tank
Sludge
Catalytic Cracking
Catalyst and Fines
Hydrotreating and
Hydrorefining Catalysts
Reforming Catalyst
HF Acid Alkylation
Sludge
Sludge from Sulfur
Removal
Fines and Off-spec
Product from Thermal
Processing
Spent Caustic
Amine solution
Discussion of RC Eliminated1
Permanent shutdown of crude units eliminated desalter waste, distillation tower waste,
crude tank sludge. The two refineries likely substituted unfinished products from
other refineries for crude oil as their raw material.
Tank mixers are used to reduce tank sludge accumulation.
Tank mixers are used to reduce tank sludge accumulation.
Caked FCC catalyst (generated at turnaround) were eliminated due to equipment and
process changes.
Hydroprocessing catalysts are now nonhazardous due to a new sweep procedure,
reducing facility's requirement to ship as hazardous waste.
Reforming catalysts are now nonhazardous due to a new sweep procedure, reducing
facility's requirement to ship as hazardous waste.
Spent caustic from the HF alkylation system were previously sent offsite for deepwell
injection. A treater now generates solid calcium fluoride and an aqueous phase that is
sent to wastewater treatment.
Amine reclaimer bottoms are no longer produced due to equipment and process
changes.
Amine treating clay replaced with regenerative carbon.
Corrosion inhibitors are used to prevent sludge accumulation on the amine filters.
Coke fines and coke are sold instead of landfilled.
Two refineries installed distillate hydrodesulfurization units and took caustic units out
of service, eliminating spent caustic residuals.
"Sulfinol, from gas liquid unit," was eliminated due to equipment/ process
modification
Spent Merox caustic is no longer produced.
Amine treating solution is regenerated within the process by contract amine cleaning
technology. Cleaning process generates clean amine and heat stable salts, which are
managed in the wastewater treatment system.
Equipment modification (NOS)
Waste Minimization for
Petroleum Refineries
37
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Table IV-2. Detailed Residual Elimination Information Available
from Section XI of Surveys
Residual of Concern
Desalter sludge
ASO
Isomerization residuals
Merox unit sand filter
General Responses
Discussion of RC Eliminated1
Permanent shutdown of crude units eliminated desalter waste, distillation tower waste,
crude tank sludge
Desalter no longer in operation
Equipment modification (NOS)
Recycled through the slop oil system.
Discontinued use of the isomerization process.
Improved draining and washing/steaming the filter before removing the sand.
Removes oil and caustic contaminants allowing material to be recycled into roadway
antiskid.
Catalysts are recycled instead of landfilled.
None eliminated, but some reduced.
Opportunities are limited because of contaminants in crude oil requiring removal,
required use of catalysts in process equipment, filters to keep product on-spec, use of
caustic and wash water to remove impurities. However, there are options for waste
minimization through recycling.
1. The responses of each facility are presented here, edited only slightly for clarity.
Waste Minimization for
Petroleum Refineries
38
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Table IV-3. Detailed Regulatory Barriers Reported from Section XI of Surveys
Residual of Concern
Crude Tank Sludge
Unleaded Gasoline
Tank Sludge
CSO Sludge
Catalytic Cracking
Catalyst and Fines
Hydrotreating and
Hydrorefining
Catalysts
HF Acid Alkylation
Sludge
Sulfur Complex
Catalyst
Spent Caustic
ASO
Discussion of Regulatory Barrier1
Many tanks (crude and product) may require accelerated cleanout to comply with
upcoming OPA-90 regulations
Regulatory barriers are associated with permitting: transportable treatment permit for
sludge treatment.
Many tanks (crude and product) may require accelerated cleanout to comply with
upcoming OPA-90 regulations
Oxygenated fuels program required accelerated tank cleaning schedule to store MTBE-
blended fuel. If MTBE program is discontinued, tanks may again require cleaning prior to
changing product service
Many tanks (crude and product) may require accelerated cleanout to comply with
upcoming OPA-90 regulations
Catalysts could be used as micronutrients in fertilizer. This represents a large beneficial
reuse/cost reduction opportunity. However, current regulation 40 CFR 26 1 .2(e)(2)(i)
excludes use to make a fertilizer.
FCC fines result from inefficient air pollution control equipment and cannot be eliminated.
Reformulated gasoline and low sulfur/aromatic diesel rules will result in more spent
hydrotreating catalyst
Regulatory barriers are associated with permitting: hazardous waste permitting for catalyst
regeneration facilities result in a lack of such facilities and more landfilling of residuals
which could be sent to such facilities.
Extending catalyst life results in permit modification since a higher metals content would
result.
Catalysts could be used as micronutrients in fertilizer. However, current regulation 40
CFR 26 1 .2(e)(2)(i) excludes use to make a fertilizer. This represents a large beneficial
reuse/cost reduction opportunity.
Fluoride limits on NPDES permit affects potential to reduce alky sludge
Alky scrubber solution result from air pollution permits and cannot be eliminated.
Catalysts could be used as micronutrients in fertilizer. This represents a large beneficial
reuse/cost reduction opportunity. However, current regulation 40 CFR 26 1 .2(e)(2)(i)
excludes use to make a fertilizer.
Any regulation of caustics will be a blow to refinery's attempt to reuse and recycle.
BIF regulations are so involved that ASO combustion, which was under consideration at
one time, was canceled.
Waste Minimization for
Petroleum Refineries
39
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Table IV-3. Detailed Regulatory Barriers Reported from Section XI of Surveys
Residual of Concern
Discussion of Regulatory Barrier'
General Comments:
Permitting
90 day storage prevents onsite treatment for this Alaska refinery.
Movement of secondary residuals and recyclables among different facilities owned by
same corporation requires special permission from various federal agencies.
CBI comments from two refineries in California and Pennsylvania discuss permitting
hurdles with waste treatment units.
General Responses:
Cokers
Significant reduction of hazardous waste could occur if facilities could legally transfer
RCRA wastes from a facility to another, for injection to coker, without becoming a TSD.
If RCs are listed, the facilities decision to recycle the residuals in a proposed coker would
depend on whether the coker requires a RCRA permit.
General Responses:
Recycling
Recyclable materials could be exempted from regulation when recycled at another facility.
Could continue to regulate certain methods of recycling (e.g., use on land) and exempt
others. Options to reuse and recycle hazardous waste are hampered by these regulations.
If RCs are listed, recycling and reuse could be encouraged by allowing low flash point
liquids to be reused for fuel and high/low pH materials for their characteristic properties.
NJ regulation that spent material being recycled or reused are not exempt from solid waste
regulations.
Reuse and recycling, particularly those conducted offsite, can be very difficult for
hazardous wastes. Residuals are properly managed at present.
General Responses:
Other
No barriers presently exist. If RCs are listed, source reduction efforts may be hampered if
they involve further onsite processing (treatment). Sufficient regulatory controls are in
place for storage, treatment, and processing of these RCs.
The rapidly expanding universe of hazardous waste created by new regulations keeps us
busy looking for approved disposal methods for the new wastes and does not allow time to
look for source reduction methods for existing wastes. Many listed regulated wastes could
be removed from the hazardous waste envelope if the delisting process could be
streamlined and risk based criteria could be applied on a case-by-case basis.
Facility is measured by reductions in hazardous waste more than nonhazardous waste. If
wastes are listed, landfill exclusions reduce ability to be disposed of by cheaper methods.
Congress, EPA, and much of industry have developed a mindset of command-and-control,
end-of-pipe treatment approaches based on 20 years of experience. EPA should provide
incentives to develop source reduction strategies and increase flexibility to implement
process changes without undo permitting burdens. More statutory flexibility must be
provided in regulations by setting "targets" without prescribing how the target should be
met. More cost-effective programs can be designed by allowing companies to consider
site-specific factors and focus on results.
1. The responses of each facility are presented here, edited only slightly for clarity. Note that only some of these
responses are relevant to listing RCs; other responses are relevant to study RCs or are general in nature.
Waste Minimization for
Petroleum Refineries
40
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Table IV-4. Recycling of RCs Reported in Section VI of Survey
RC
Crude Oil Tank Sludge
CSO Sludge
Unleaded Gasoline Tank Sludge
Residual Oil Tank Sludge
Desalting Sludge
Catalytic Cracking
Catalyst and Fines
Catalyst
Fines
Hydrotreating Catalyst
Hydrorefming Catalyst
Hydrocracking Catalyst
Reforming Catalyst
Isomerization Catalyst
Treating Clay from Isomerization or
Extraction
Polymerization Catalyst
Sulfuric Acid Alkylation Catalyst
Sulfuric Acid Alkylation Sludge
Total
1992
Quantity,
MT1
22,017
24,010
3,583
9,107
4,841
124,061
67,816
5,640
18,634
18,029
3,613
337
2,471
4,119
1,760,071
608
Total
#of
Streams
(1992)'
127
46
141
43
117
181
108
201
72
77
115
20
65
39
59
16
Percent, Quantity
Recycled/ Reused in 1 992
Onsite
44
2
3
3
1
3
<1
4
0
1
2
0
0
18
19
0
Offsite
4
8
5
11
40
71
17
76
83
85
96
87
3
13
81
13
Total
48
10
8
14
41
74
17
80
83
86
98
87
3
31
>99
13
Percent, # of Streams
Recycled/ Reused in 1 992
Onsite
23
9
9
23
5
6
1
4
0
1
7
0
0
3
19
0
Offsite
7
7
1
5
17
62
20
65
89
79
86
85
14
18
66
13
Total
30
16
10
28
22
68
21
69
89
80
93
85
14
21
85
13
Predominant Recycle/Reuse
Methods
Onsite recovery in crude unit
Onsite recovery
Onsite recovery in coker
Onsite recovery
Offsite use as fuel
Reuse at another refinery; offsite
cement kiln
Offsite cement kiln
Offsite catalyst regeneration/
metals reclamation
Offsite catalyst regeneration/
metals reclamation
Offsite catalyst regeneration/
metals reclamation; reuse at
another refinery
Offsite catalyst regeneration/
metals reclamation
Offsite catalyst regeneration/
metals reclamation
Offsite catalyst regeneration/
metals reclamation
Offsite use as fertilizer
Offsite acid recovery
Offsite acid recovery
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Table IV-4. Recycling of RCs Reported in Section VI of Survey
RC
Acid Soluble Oil
HF Catalyst
HF Alkylation Sludge
Treating Clay from Alkylation
Sludge from Sulfur Removal
Catalyst from
Sulfur Complex
Glaus
Tail Gas
Off-Spec Sulfur
Off-spec Treating Solution from
Sulfur Removal
Fines and Off-spec Product from
Thermal Processing
Off-spec Product from Residual
Upgrading
Sludge from Residual Upgrading
Treating Clay from Lube Oil
Treating Clay from Clay Filtering
Spent Caustic
Total
1992
Quantity,
MT1
33,493
152
11,288
2,895
8,520
3,819
361
9,647
23,881
194,262
800
242
733
8,990
917,656
Total
#of
Streams
(1992)'
73
3
30
86
301
95
23
90
96
110
1
32
19
231
712
Percent, Quantity
Recycled/ Reused in 1 992
Onsite
21
0
12
0
<1
<1
0
<1
5
5
100
7
48
<1
19
Offsite
13
0
0
50
4
22
52
5
33
87
0
2
34
7
50
Total
34
0
12
50
4
22
52
5
38
92
100
9
82
7
69
Percent, # of Streams
Recycled/ Reused in 1992
Onsite
21
0
3
0
2
1
0
6
10
3
100
3
63
1
15
Offsite
10
0
0
22
8
21
56
9
8
43
0
16
5
12
31
Total
31
0
3
22
10
22
56
15
18
46
100
19
68
13
46
Predominant Recycle/Reuse
Methods
Onsite recovery; offsite use as fuel
_____
Onsite recovery in coker
Offsite metals reclamation
Offsite carbon reclamation
Offsite cement kiln
Offsite metals reclamation
Sell with product
Offsite regeneration/ metals
reclamation
Sell with coke product
Recycle to process
Sell with product
Onsite regeneration
Offsite regeneration/ metals
reclamation
Offsite reclamation/reuse; onsite
use in WWTP for pH control
1 Includes streams with unknown or unreported quantities.
Data source: 1992 RCRA ง3007 Survey data.
-------
Table IV-5. Summary of Waste Minimization Information Available
from Engineering Site Visits
Residual of Concern
Crude Tank Sludge
Unleaded Gasoline
Tank Sludge
CSO Sludge
Residual Oil Tank
Sludge
Catalytic Cracking
Catalyst and Fines
Hydrotreating and
Hydrorefining
Catalysts
Reforming Catalyst
Sulfuric Acid
Alkylation Catalyst
Sulfuric Acid
Alkylation Sludge
Hydrofluoric Acid
Alkylation Sludge
Sludge from Sulfur
Removal
Catalyst from Sulfur
Complex
Fines and Off-spec
Product from
Thermal Processing
# of Facilities
Reporting
Waste
Minimization
12
1
12
12
11
10
7
5
1
4
5
2
4
Source Reduction Techniques
Sell for reprocessing; onsite recycling in another unit; recycle to crude
tanks; onsite treatment to recover oil; spill prevention precautions
decrease quantity of contaminated soil during turnaround.
Recycle to other gasoline tanks.
In-line solid settlers; new cyclones decrease fines in reactor product;
hydroclones recycle fines in slurry oil to FCC; spill prevention
precautions decrease quantity of contaminated soil during turnaround;
recycle to other CSO tank or coker.
Techniques similar to those used for crude oil tank sludge and CSO
sludge can be used.
E-cat sent offsite to another unit; sell catalyst and fines outside of
refining industry; e-cat reused onsite in another unit.
Offsite metals reclamation; offsite regeneration ad reintroduction to
reactor; onsite treatment to reduce dust generation; separation of support
material for onsite reuse ; upstream process changes to eliminate catalyst
poisons.
Offsite metals reclamation; increasing time between turnaround by
optimizing feeds; separation of support material for onsite reuse
Onsite regeneration; offsite regeneration; process change to decrease oil
content of spent acid.
Reduced the number of times acid level was tested in the reactor.
Reuse/sale of neutralized fluoride salt; non-generation of solid fluoride
salt.
Replacing filter elements with metal screens; using MDEA rather than
MEA decreases the generation and removal of heat stable salts; control
of heat stable salts using caustic.
Offsite metals recovery (both Glaus and SCOT).
Internal recycle of coker water; improved operation keeps coke fines out
of sewers; filter aid in treating other waste; sell with product coke.
Waste Minimization for
Petroleum Refineries
43
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Table IV-5. Summary of Waste Minimization Information Available
from Engineering Site Visits
Residual of Concern
Spent Caustic
Alkylation Treating
Clay
Off-Spec Treating
Solution for I^S
Removal
Off-spec Sulfur
Clay
# of Facilities
Reporting
Waste
Minimization
11
1
4
1
1
Source Reduction Techniques
Neutralization and recovery of HjS prior to discharge to WWTP;
substitution for fresh caustic in WWTP; sold to Meridiem; process
changes to reduce spent caustic generation.
Distillation is used to dry the alkylation feed, eliminating the need for
molecular sieve (which would require the infrequent generation of a
solid residual).
Replacement of cloth filter with an etched metal mechanical filter
reduces amine loss to the wastewater treatment plant during
maintenance; capture and recycle of amine during cloth filter bag
replacement via sump; recycle of all amine-containing water in the
sulfur unit via sump.
Waste sulfur residual from equipment "low points," presently generated
daily, will be eliminated with the installation of a newly-designed
system.
Jet fuel treating clay is regenerated once by back-washing the clay bed
with jet fuel to "fluff' the clay and alleviate the pressure drop.
Waste Minimization for
Petroleum Refineries
44
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Table IV-6. Bibliography to Waste Minimization Documents
Waste
Reference
Subject
Crude Oil, CSO, Unleaded, and Residual Oil Tank Sludges
Tank bottoms
(applicable to
different sludges)
Crude Oil Tank
Sediments
Tank emissions
"Waste Minimization in the Petroleum Industry: A
Compendium of Practices," API, November, 1991.
"Tank-Cleaning Method Removes, Processes F037
Waste," Oil & Gas Journal, October 9, 1995.
"Re-refiner Fluidizes Tank Residue Using Portable
Mixer," Oil & Gas Journal, September 5, 1994.
Emery, G.E., "Tank-Bottoms Reclamation Unit
Upgraded to Meet Stricter Rules," Oil & Gas
Journal, April 12, 1993.
"Refinery Seeks Way to Use Oil Storage Tank
Residue," Hydrocarbon Processing, April 1993.
Davis, G.B., Goss, M.L., Schoemann, P., and Tyler,
S.S., "Crude Oil Tank-Cleaning Process Recovers
Oil, Reduces Hazardous Waste," Oil & Gas Journal,
December 13, 1993.
Rhodes, A., "New Process Effectively Recovers Oil
from Refinery Waste Streams," Oil & Gas Journal,
August 15, 1994.
"Bulk Heating Cleans Paraffinic Bottoms from Crude
Tanks," Oil & Gas Journal, February 20, 1995.
"New Equation Estimates Emissions from Tank
Turnovers," Oil & Gas Journal, September 25,
1995.
"TAPS Storage Tank Bottoms Fitted With Improved
Cathodic Protection," Oil & Gas Journal, October
23, 1995.
Sludge formation can be
minimized by mixing contents of
tank.
Case study of ex-situ sludge
dewatering/deoiling. Tank sludge
is pumped to a centrifuge using a
cutter stock. The sludge volume
reduction was over 90 percent.
The tank stored wastewater and
sludge.
A portable mixer was used to cut
lighter oil into the partially gelled
residue.
Recycling through equipment
modification.
Energy recovery.
Raw material recovery.
Technology modification.
Diluent plus heat was successfully
used to clean six Canadian tanks.
The generated solvent/sludge was
sold, and sludge remaining in the
tank was removed by
conventional methods.
Discusses techniques that affect
VOC loss from tanks and how to
estimate VOC loss.
Case study of new cathodic
protection for Alaska crude tanks.
Cathodic protection is an
established method of preventing
tank corrosion and, therefore,
releases.
Waste Minimization for
Petroleum Refineries
45
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Table IV-6. Bibliography to Waste Minimization Documents
Waste
Reference
Subject
Desalting Sludge ||
Desalting Sludge
"Waste Minimization in the Petroleum Industry: A
Compendium of Practices," API, November, 1991.
"Filtration Method Efficiently Desalts Crude in
Commercial Test," Oil & Gas Journal, May 17,
1993.
D.T. Cindric, B. Klein, A.R. Gentry and H.M.
Gomaa. "Reduce Crude Unit Pollution With These
Technologies," Hydrocarbon Processing, August,
1993.
Rhodes, A., "New Process Effectively Recovers Oil
from Refinery Waste Streams," Oil & Gas Journal,
August 15, 1994.
Practices described: 1 . Shear
mixing used to mix desalter wash
water and crude. 2. Turbulence
avoided by using lower pressure
water to prevent emulsion
formation.
Alternative process, single-stage
filtration, reduces sludge
generation.
Includes topic of more effective
separation of phases in desalter.
Technology modification.
Fluid Catalytic Cracking (FCC) Catalyst and Fines
FCC Operations
FCC Catalyst and
Fines
FCC fines
"NPRA Q&A Conclusion: Refiners Exchange
Experiences on FCC Problems, Coking Operation,"
Oil & Gas Journal, May 2, 1994.
Leemann, IE., "Waste Minimization in the
Petroleum Industry," JAPCA, June 1988.
Waste Minimization in the Petroleum Industry: A
Compendium of Practices. American Petroleum
Institute. November 1991.
"Generation and Management of Residual Materials,"
API. August 1993.
"Question & Answer Session on Waste Issues,"
NPRA Environmental Conference Proceedings,
September 18-20, 1994.
"Stepwise Method Determines Source of FCC
Catalyst Losses," Oil & Gas Journal, August 28,
1995.
Preventative maintenance.
Recycling.
Recycling.
Recycling.
Recycling.
Troubleshooting techniques
identifies catalyst leaks for future
equipment maintenance.
Waste Minimization for
Petroleum Refineries
46
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Table IV-6. Bibliography to Waste Minimization Documents
Waste
FCC Catalyst
Reference
Sarrazin, P., Cameron, C.J., Barthel, Y., and
Morrison, M.E., "Processes Prevent Detrimental
Effects from As and Hg in Feedstocks," Oil & Gas
Journal, January 25, 1993.
Wong, R.F., "Increasing FCC Regenerator Catalyst
Level," Hydrocarbon Processing, November 1993.
Dougan, T.J., Alkemade, U., Lakhanpal, B., and
Boock, L.T., "New Vanadium Trap Proven in
Commercial Trials," Oil & Gas Journal, September
26, 1994.
"Refiners Discuss Fluid Catalytic Cracking At
Technology Meeting," Oil & Gas Journal, April 24,
1995.
Subject
Equipment modification.
Process modification.
Equipment modification.
Increasing the oxygen content of
regenerator air may quicken the
catalyst deactivation rate.
Hydrotreating, Hydrorefining, Hydrocracking Catalyst
Hydroprocessing
Catalyst
"Waste Minimization in the Petroleum Industry: A
Compendium of Practices," API, November, 1991.
Berrebi, G., Dufresne, P., and Jacquier, Y.,
"Recycling of Spent Hydroprocessing Catalysts:
EURECAT Technology," Environmental Progress,
May 1993.
Gorra, F., Scribano, G., Christensen, P., Anderson,
K.V., and Corsaro, O.G, "New Catalyst, Improve
Presulfiding Result in 4+ Year Hydrotreater Run,"
Oil & Gas Journal, August 23, 1 993.
"Generation and Management of Residual Materials,"
API, August 1993.
"Petroleum-derived Additive Reduces Coke on
Hydrotreating Catalyst," Oil & Gas Journal,
December 27, 1993.
Monticello, D.J., "Biocatalytic Desulfurization,"
Hydrocarbon Processing, February, 1 994.
"NPRA Q&A 1 : Refiners Focus on FCC,
Hydroprocessing, and Alkylation Catalyst," Oil &
Gas Journal, March 28, 1994.
Practices listed: 1 . Metals
reclamation. 2. Recycling to
cement. 3. Recycling to fertilizer
plants.
Metals reclamation.
Material substitution to extend
catalyst life.
Recycling.
Process modification extends life
of catalyst.
An alternative to metal catalysts is
the development of
microorganisms that can catalyze
the reaction.
Methods in improving catalyst life
and performance: regeneration
and top-bed skimming.
Waste Minimization for
Petroleum Refineries
47
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Table IV-6. Bibliography to Waste Minimization Documents
Waste
Reference
Subject
Hydroprocessing
Catalyst (Cont.)
"Industry Briefs," Oil & Gas Journal, January 2,
1995.
Patent received for
commercialization of petroleum
biocatalytic desulfurization
process.
"Coke, Sulfur Recovery from U.S. Refineries
Continues to Increase," Oil & Gas Journal, January
2,1995.
Commercialization of petroleum
biocatalytic desulfurization
process, trends affecting sulfur
production and removal (and
associated waste generation).
"Bug Process Studied for Low Sulfur Diesel," Oil &
Gas Journal, April 3,1995.
A pilot plant for a biocatalytic
desulfurization process may be
constructed in France and
commercialized in 1996 or 1997.
"HP Innovations," Hydrocarbon Processing,
November 1995.
Biocatalytic desulfurization.
Similar to Oil & Gas Journal,
April 3, 1995, page 39.
"Hydrotreating Operations Discussed At Refining
Meeting," Oil & Gas Journal, June 12, 1995.
"Scale baskets" placed at the front
of reactors may or may not keep
debris out of the catalyst bed and
extend the time between
turnarounds.
"Catalyst Handling, Disposal Become More
Important in Environmental Era," Oil & Gas
JournaI,Maich 18, 1996.
Catalyst loading, unloading, and
offsite reclamation are described.
Operations to improve catalyst
handling while loading and
unloading are described.
Hydrocracking
Catalyst and
Operations
"New Hydrocracking Catalysts Increase Throughput,
Run Length," Oil & Gas Journal, June 26, 1995.
Discusses operational changes to
product slate. No waste
generation aspects.
"Catalyst Separation Method Reduces Platformer
Turnaround Costs," Oil & Gas Journal, September
18,1995.
Technology separates highly-
deactivated catalyst from reusable
catalyst, allowing less catalyst to
be shipped offsite. Technique has
been applied to reforming and
hydrocrackine catalyst.
Waste Minimization for
Petroleum Refineries
48
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Table FV-6. Bibliography to Waste Minimization Documents
Waste
Hydrorefining
Catalyst
Reference
"Japanese Refiner Solves Problem in Resid
Desulfurization Unit," Oil & Gas Journal,
November 13, 1995.
"Simple Changes Reduce Catalyst Deactivation,
Pressure Drop Buildup," Oil & Gas Journal,
November 20, 1995.
Subject
By adjusting operating conditions,
catalyst type, and catalyst loading,
one refinery increased the time
between catalyst replacement by 6
months.
Same case study as Nov. 1 3
article, with similar topics.
Reforming Catalyst
Reforming Catalyst
J. Liers, J. Mensinger, A. Mosch, W. Reschefilowski,
"Reforming Using Erionite Catalysts," Hydrocarbon
Processing, August, 1993.
"NPRA Q&A 1 : Refiners Focus on FCC,
Hydroprocessing, and Alkylation Catalyst," Oil &
Gas Journal, March 28, 1994.
"Olefins Can Limit Desulfurization of Reformer
Feedstock," Oil & Gas Journal, July 3, 1995.
"Catalyst Separation Method Reduces Platformer
Turnaround Costs," Oil & Gas Journal, September
18, 1995.
The platinum catalyst together
with erionite increases
isomerization.
Regeneration.
Choosing a hydrotreating catalyst
that hydrogenates olfins will
improve sulfur removal, thus
prevent deactivation of reforming
catalyst.
Technology separates highly-
deactivated catalyst from reusable
catalyst, allowing less catalyst to
be shipped offsite. Technique has
been applied to reforming and
hydrocracking catalyst.
Alkylation Unit (HF Acid Releases)
HF Alkylation
"Alkylation Safety Major Topic at Oil & Gas Journal
Seminar.," Oil & Gas Journal, January 16, 1995.
"Survey Reveals Nature of Corrosion in HF Alky
Units," Oil & Gas Journal, March 6, 1 995.
"Alkylate - A Key Gasoline Component,"
Hydrocarbon Processing, August 1995.
"New HF Detector Accepted for Use by Refining
Consortium," Oil & Gas Journal, February 1 9,
1996.
Discusses controls at HF acid
alkylation to mitigate acid leaks.
Lists materials, maintenance
practices, problems found during
survey of half of world's HF
alkylation units.
Additives to HF acid alkylation
are being developed to lessen risk
during spill.
An improved method of detecting
HF acid leaks has been tested at
one refinery and will be installed
at others.
Waste Minimization for
Petroleum Refineries
49
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Table IV-6. Bibliography to Waste Minimization Documents
Waste
Reference
Subject
HF and Sulfuric Acid Catalyst
Alkylalion catalysts
"NPRA Q&A 1 : Refiners Focus on FCC,
Hydroprocessing, and Alkylation Catalyst." Oil &
Gas Journal. March 28, 1994.
Rhodes, A.K. "Searches for New Alkylation
Catalysts, Processes Forge Ahead." Oil & Gas
Journal. August 22, 1 994.
"U.S. Refiners Must Increase Alkylation Capacity to
Meet Demand" Oil & Gas Journal. August 22,
1994.
Rhodes, A.K. "New Process Schemes, Retrofits,
Fine Tune Alkylation Capabilities." Oil & Gas
Journal. August 22, 1994.
"Pilot-plant results in on fixed-bed alkylation
process." Oil & Gas Journal. April 1, 1996.
"HP Innovations," Hydrocarbon Processing,
February 1996.
Solid acid catalyst substitution.
Equipment modification. Process
modification.
Solid catalyst substitution.
Process substitution. Process
modification.
Solid catalyst for alkylation out of
the test stage and in the process of
being put on the market.
Solid catalyst for gasoline
alkylation has been developed and
will be tested. It would compete
with systems using liquid sulfuric
or hydrofluoric acid catalysts.
Acid Soluble Oil
ASO
"Portuguese Refiner Starts Up New Gasoline
Complex," Oil & Gas Journal, March 13, 1995.
Feed change to alkylation unit (by
installing a unit to reduce the
butadiene content of feed) is
expected to decrease ASO
generation.
Treating Clay from Alkylation
Alkylation treating
clay
"Conoco Refinery Markets Fluorinated Alumina," Oil
& Gas Journal, February 1, 1993.
Used clay is sold to an aluminum
plant.
HF Alkylation Sludge
HF Sludge
Waste Minimization in the Petroleum Industry: A
Compendium of Practices. American Petroleum
Institute. November 1991.
Waste Minimization for
Petroleum Refineries
50
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Table IV-6. Bibliography to Waste Minimization Documents
Waste
Reference
Subject
Off-spec Product and Fines from Thermal Proce ses
Coke fines
"NPRA Q&A Conclusion: Refiners Exchange
Experiences on FCC Problems, Coking Operation."
Oil & Gas Journal. May 2, 1994.
"Choosing a Coke Recovery System," Hydrocarbon
Processing, September 1995.
Process modification. Process
control.
Details coke and coke fine
collection devices.
Spent Treating Solution and Other Sulfur Plant Wastes
Spent amine
Sulfur plant
Waste Minimization in the Petroleum Industry: A
Compendium of Practices. American Petroleum
Institute. November 1991.
"Generation and Management of Residual Materials,"
API, August 1993.
Stewart, E.J. and Lanning, R.A., "Reduce Amine
Plant Solvent Losses, Part 1 ," Hydrocarbon
Processing, May, 1 994.
Stewart, E.J. and Lanning, R.A., "Reduce Amine
Plant Solvent Losses, Part 2," Hydrocarbon
Processing, June, 1 994.
"Clean Amine Solvents Economically and On-line,"
Hydrocarbon Processing, August 1995.
"HP Innovations," Hydrocarbon Processing,
December 1995.
"Liquid Catalyst Efficiently Removes H2S From
Liquid Sulfur," 'Oil & Gas Journal, July 17, 1989.
Recycling.
Recycling.
Process modification.
Process modification.
Heat stable salts were removed
from one refinery's amine system
while on-line. Alternatives
included disposing system's
contents.
Amine entrainment in LPG was
reduced following installation of
coalescers. Amine was kept
within the system, reducing raw
material requirements for make-
up.
Lower catalyst quantities needed
to remove H2S in the sulfur
degassing process.
Spent Caustic from Liquid Treating
Spent Caustic
Waste Minimization in the Petroleum Industry: A
Compendium of Practices. American Petroleum
Institute. November 1991.
Recycling.
Waste Minimization for
Petroleum Refineries
51
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Table IV-6. Bibliography to Waste Minimization Documents
Waste
Reference
Subject
Treating Clay from Clay Filtering
Spent clay
Waste Minimization in the Petroleum Industry: A
Compendium of Practices. American Petroleum
Institute. November 1991.
Non-RC Solid Wastes from Refining
Various wastes and
pollution prevention
planning
Various wastes
Sludges
Wastewater
treatment sludge
Sludge processing
Hethcoat, H.G. "Minimize Refinery Waste."
Hydrocarbon Processing. June 1990.
Waste Minimization in the Petroleum Industry: A
Compendium of Practices. American Petroleum
Institute. November 1991.
"Generation and Management of Residual Materials."
API. August 1993.
"Environmental Processes '93 : Challenge in the
'90's," Hydrocarbon Processing, August, 1993.
"Waste Recycling Project Receives Go-Ahead,"
Hydrocarbon Processing, August 1995.
Kuriakose, A.P., Manjooran, S. Jochu Baby,
"Utilization of Refinery Sludge for Lighter Oils and
Industrial Bitumen," Energy & Fuels, 8(3), May-
June, 1994.
"New Process Effectively Recovers Oil From
Refinery Waste Streams," Oil & Gas Journal,
August 15, 1994.
"HP Informer," Hydrocarbon Processing, October
1995.
"Industry Briefs," Oil & Gas Journal, December 25,
1995.
P2 planning. Processes
highlighted: crude tank sludge,
coke fines, spent amine, and FCC
catalyst.
Discusses recycling, source
reduction for many process and
wastewater treatment wastes from
refining.
Recycling and source reduction
methods.
A variety of technologies
described, such as bioslurry
treatment of oily wastes, oily-
waste recovery, and
evaporation/solvent extraction.
A facility will be constructed to
convert chlorinated wastes and
other wastes into carbon raw
material via a molten bath.
Utilizing waste sludge.
Enhanced separation of oil, water
and solids.
Onsite thermal desorption unit
recovers oil and decreases volume
of disposed waste.
Oil from hazardous waste will be
recovered in an unspecified
recycling system at three
refineries; the solids will be
burned in cement kilns.
Waste Minimization for
Petroleum Refineries
52
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Table IV-6. Bibliography to Waste Minimization Documents
Waste
Hydrogen Production
Reference
"Alternative Technologies to Steam-Methane
Reforming" Hydrocarbon Processing, November
1995.
Subject
Discusses trade-offs including
emissions for alternative
hydrogen-generating technology.
Related Environmental Topics
Pollution Prevention
Planning
Audits
Wastewater
treatment
Air emissions from
wastewater treatment
Multimedia
emissions
Emissions at Foreign
refineries
"Amoco-U.S. EPA Pollution Prevention Project,
Yorktown, Virginia, Project Summary." January
1992 (Revised June 1992).
Radecki, P.P., Hertz, D.W., and Vinton, C. "Build
Pollution Prevention Into System Design."
Hydrocarbon Processing. August 1994.
"Question & Answer Session on Waste Issues."
NPRA Environmental Conference Proceedings.
September 18-20, 1994.
Richardson, K.E. "Refinery Waste Minimization."
NPRA Environmental Conference Proceedings.
September 18-20, 1994.
"Companies Wary of Use of Environmental Audits,"
Oil & Gas Journal, April 17, 1995.
"Croatian Refiner Meets Waste Water Treatment
Standards, Reduces Fines," Oil & Gas Journal,
November 27, 1995.
"HP Impact," Hydrocarbon Processing, December
1995.
"How to Renovate a 50-year-old Wastewater
Treating Plant," Hydrocarbon Processing, February
1996.
"U.S. Refinery Emissions at Issue," Oil & Gas
Journal, December 11, 1995.
"HP Impact," Hydrocarbon Processing, February
1996.
Pollution Prevention Planning
P2 planning.
Pollution Prevention Planning
Pollution Prevention Planning
Survey of many industries shows
companies fear enforcement risks
from self-initiated audits.
Installation of end-of-pipe control
decreases hydrocarbons in
effluent, but notes problems to
recycling the water in the plant.
Oil is recovered.
Liquid-liquid extraction may be
used in the future for wastewater
treatment.
Documents retrofitting required to-
comply with benzene NESHAPs
requirements.
EOF reported TRI releases and
other factors affecting chemical
reporting for refineries.
Report summarizes disposal
patterns at European refineries.
Waste Minimization for
Petroleum Refineries
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Table IV-6. Bibliography to Waste Minimization Documents
Waste
Used oil
Oil spills
Reference
"Oil Recycling Moves Upscale," Oil & Gas Journal,
March 13, 1995.
"Re-refining Process Expands Worldwide,"
Hydrocarbon Processing, August 1995.
"U.S. Spill Cleanup Capability Shows Marked
Improvement," Oil & Gas Journal, January 1 , 1 996.
Subject
U.K. company reprocesses and
recycles used oil for fuel.
A new refinery is operating,
which processes used oil, heavy
refining bottoms, and other low
value feedstocks.
Reports on equipment availability
and guidelines for spill cleanup.
Waste Minimization for
Petroleum Refineries
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V. Conclusions
As stated by several refineries in Table IV-2 of this report, source reduction has limitations
within refineries due to the nature of the raw material, crude oil. When reporting source
reduction activities, most refineries are actually reporting waste minimization because the bulk of
their activities are recycling activities, such as oil recovery and offsite sales. However, given this
limitation, some refineries are conducting or experimenting with innovative source reduction or
waste minimization activities that are not widely used.
This report is limited by the data contained in the RCRA ง3007 Survey responses. The
differences in interpretation between source reduction and recycling among each of the refineries
are reflected in their responses. While the survey responses are helpful in identifying which RCs
have greater source reduction activities than others, the responses lack detail as to what these
practices are. In addition, some facilities may not be able to report accurate residual quantities in
Section VI, especially for those residuals that are not shipped offsite and instead recycled onsite.
In these cases, facilities used engineering judgement of often report that estimates cannot be
made. This inaccuracies will serve to possibly skew the volumes presented in this report, but
would generally not change the number of facilities affected.
Waste Minimization for
Petroleum Refineries
55
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