c/EPA
United States Industrial Environmental Research EPA-600/2-79-069
Environmental Protection Laboratory March 1979
Agency Research Triangle Park NC 27711
Research and Development
Control Technology
Evaluation for Gasoline
Loading of Barges
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
EPA REVIEW NOTICE
This report has been reviewed by the U.S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the contents necessarily
reflect the views and policy of the Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-79-069
March 1979
Control Technology Evaluation
for Gasoline Loading of Barges
by
D. Gee and W. M. Talbert
Pullman Kellogg
16200 Park Row, Industrial Park Ten
Houston, Texas 77084
Contract No. 68-02-2619
Task No. 9
Program Element No. 1AB604B
EPA Project Officer: Irvin A. Jefcoat
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
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CONTENTS
Table of Contents ii
Index of Figures v
Index of Tables vi
1.0 INTRODUCTION 1
1.1 PURPOSE 1
1.2 SOURCES AND TECHNIQUE 2
2.0 SUMMARY 3
3.0 CONCLUSIONS AND RECOMMENDATIONS . 6
3.1 CONCLUSIONS 6
3.2 RECOMMENDATIONS . . . 8
4.0 DISCUSSION 9
4.1 DESCRIPTION AND OPERATION OF A GASOLINE
BARGE LOADING TERMINAL AND A BARGE 9
4.2 DISCUSSION OF CONTROL TECHNOLOGIES IN
RELATION TO GASOLINE LOADING 12
4.2.1 Carbon Adsorption . 12
4.2.2 Refrigeration 16
4.2.3 Thermal Incineration 19
11
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CONTENTS (Cont)
4.3 GENERAL DISCUSSION OF SAFETY TECHNOLOGY .... 22
4.3-1 Fire and Explosion 23
4.3.2 Barge Overfilling 29
4.4 APPLICATIONS OF SAFETY AND CONTROL
TECHNOLOGIES . 29
4.4.1 Thermal Incineration by Dilution .... 36
4.4.2 Thermal Incineration-with Saturation . . 36
4.4.3 Thermal Incineration with Fuel Gas
Blanketing 39
4.4.4 Thermal Incineration with N2
Blanketing . .' 41
4.4.5 Thermal Incineration with Inert
Gas Generation 43
4.4.6 Carbon Adsorption with Saturation .... 43
4.4.7 Carbon Adsorption with N2 or
Inert Gas Generator 44
4.4.8 Refrigeration with Saturation 44
4.4.9 Refrigeration with N2 or Inert
Gas Generator 45
4.4.10 Other Design Considerations 45
111
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CONTENTS (Cont)
4.5 EMISSIONS AND CONTROL EFFICIENCIES 46
4.5.1 Primary Emissions 46
4.5.2 Secondary Emissions 55
4.6 ECONOMICS 58
4.6.1 Capital Costs 59
4.6.2 Annualized Costs . 65
4.6.3 Economic Analysis 71
References 80
Appendices
A. Legend A-l
B.:. Capital Cost Data for Safety
and Control Modules B-l
- C. Companies Supplying Pricing and
Technical Information C-l
IV
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INDEX OF FIGURES
Number . Paqe
4.2.1 Carbon Adsorption Module 13
4.2.2 Refrigeration Vapor Recovery Module 17
4.2.3 Thermal Incineration Module 20
4.3.1 Hydraulic Flash Arrestor 28
4.3.2 Barge Modifications . 30 .
4.3.3 Barge Vapor Collection Manifold 31
4.4.1 Loading and Collection System Layout 33
4.4.2 Dilution Module 37
4.4.3 Saturation Module - 38
4.4.4 Fuel Gas Blanketing Module 40
4.4.5 N Blanketing Module 42
4.6.1 Cost Effectiveness Projections
Carbon Adsorption 76
4.6.2 Cost Effectiveness Projections
Refrigeration ' 77
4.6.3 Cos.-t. Effectiveness Projections
Thermal Incineration 78
4.6.4 Cost Effectiveness Projections
Comparison 79
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INDEX OF TABLES
Number Page
4.U.I Predicted Vapor Compositions 34
4.5.1 Gasoline Barge Vapor Composition 48 •
4.5.2 Barge Vapor Compositions After Safety Module ... 49
4.5.3 Manufacturers Predicted Vapor Control Unit
Efficiencies 51
4.5.4 Control efficiencies Reported In" Literature .... 52
4.5.5 Preducted Annual HC Emission Rates For Control
Cases Lb/Yr HC Emitted 56
4.6.1 Capital Cost Of Safety Modules 60
4.6.2 Capital Cost For Control Modules 62
4.6.3 Capital Costs Of Barge Loading Emission
Control Systems 64
4.6.4 Anriaalized Costs For Safety Modules 67
4.6.5. Annualized Costs For Control Modules 68
4.6.6 Annualized Costs For One Gasoline Barge
Loading Emission Control System 70
4.6.7 Cost Effectiveness For Control Cases 72
4.6.8 Summary Of Results Of Cost Effectiveness Curves . . 75
VI
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SECTION 1
INTRODUCTION
1.1 PURPOSE
This study undertakes both an assessment of feasibility
for developing new vapor control systems for loading
barges with gasoline and development of background
information for use in designing a demonstration
facility. Specifically, the study was designed to:
A. Determine the feasibility of controlling gasoline
vapors during barge-loading operations by using
carbon adsorption, refrigeration, or thermal
- incineration technologies.
B. Identify and solve the problems of safety hazards
related to vapor control.
C. Determine the achievable emission level and ex-
pected efficiency for each control technology.
D. Determine the secondary emissions resulting from
implementation of each gasoline vapor control
technology.
E. Project the capital and annualized costs for each
vapor control alternative.
-1-
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1.2 SOURCES AND TECHNIQUE
Equipment manufacturers were contacted to determine the
effectiveness, cost, and operating history of their
vapor control units. Several alternatives were pro-
posed for rendering the potentially flammable vapor
mixtures from barges non-flammable. These alternatives
included dilution with air, saturation with gasoline,
and blanketing with fuel gas or inert gases. Combina-
tions of safety and control modules were studied to.
evaluate costs, safety, emissions, and reliability.
-2-
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SECTION 2
SUMMARY
Feasibility, safety, vapor emissions and costs constitute the
basis of evaluation in this study for controlling gasoline-barge
loading emissions. The evaluation involves application of carbon
adsorption, refrigeration, and thermal incineration control
technologies to control gasoline-barge vapors. Gasoline loading
emissions consist of two portions, an arrival portion and a
generated one. Arrival emissions consist of evaporated residual
gasoline from a previous load. Generated emissions are produced
as the barge is loaded with gasoline. A hydrocarbon loading
emission factor of 4 #/1000 gallons of gasoline loaded, for
uncleaned gasoline barges, was used for economic analysis. In
practice, remitted vapors have a hydrocarbon concentration ranging
from 456 to over 50% by volume. A significant amount of these
vapors'are within the 1.45& to 8.H% nominal limits of flammability
and they represent a serious safety hazard since they introduce
flammable mixtures into the vapor control systems. Should an
ignition occur within the vapor control system, not only would it
be hazardous to the vapor control system, but a flame front could
travel by connecting pipe to the interior of the barge and ignite
the vapors within the barge. This could result in a fire and
explosion that could demolish the barge and dock facilities, and
result in loss of life.
Dilution, saturation, and inertion have been investigated as
primary safety methods for rendering the barge vapors
-3-
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non-flammable before collection and disposal or recovery. Safety
modules were developed using these methods for combination with
the three control technologies. A secondary protection device (a
hydraulic flash arrestor) is used to prevent transmission of
flames between the barge and control system in case an ignition
occurs that is caused by a primary system malfunction. Each
combination of safety module and control module was studied first
for compatibility in safety and control. The more promising
schemes were subjected to a detailed analysis of safety,
reliability, operability, control efficiency, and cost (capital
and annualized) . Eleven cases passed the initial screening and
became the basis for the balance of the study.
After studying the design and operation-of gasoline-barge loading
terminals operated by different oil companies, a hypothetical
gasoline-barge loading terminal has been formulated for use in
this report. Since design and operation of barge terminals and
shipping procedures vary substantially for the various operators,
the hypothetical barge terminal incorporates features common to
actual terminals although it can not be construed to be typical
of all terminals. The hypothetical terminal uses an annual
gasoline throughput of six million barrels per year. Two loading
berths" for gasoline barges are assumed. Maximum liquid gasoline
loading rate was 4200 gpm (6000 barrels per hour) for the
terminal. The gasoline barges are assumed to be 20,000 barrel
liquid capacity each, and they are in dedicated gasoline service.
The gasoline barge loading emissions for the terminal in the
uncontrolled base case are calculated to be 1,008,000 #HC/yr.
Control equipment/manufacturers were contacted for information
concerning capital cost estimates, control efficiencies, utility
requirements, theory of operation, safety, operating history, and
other technical features. The vendors' costs for vapor control
-4-
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units for similar applications when using carbon adsorption or
refrigeration, were roughly equal. The costs of thermal
incineration in the same applications were substantially less.
Control efficiencies estimated by the manufacturers for the
various cases were 99.9/6 for thermal incineration, 98 to 9956 for
carbon adsorption, and 91 to 9.4$ for refrigeration.
The economics of applying vapor control to gasoline barge loading
are studied here, and estimates of total installed capital costs,
annualized costs, and cost effectiveness are calculated. Capital
costs for barge modifications are also estimated. The safety
modules are found to contribute significantly to the annualized
and capital costs of the control cases. The proportion of
annualized cost attributed to the safety module ranges from 64$
to 98$ of the total. The safety module portion of total capital
cost ranges from 24$ to 70$. Cost effectiveness is calculated by
dividing the pounds of HC controlled (compared to the base case)
by the annualized cost. The most cost effective case is carbon
adsorption with inert gas generation at 8.50 #HC/$. The next two
most cost effective systems also use inert gas generation, and
are thermal-incineration (8.01 #HC/$) and refrigeration (6.08
#HC/$). At the annual throughput of six million barrels per
year, none of the schemes are profitable, and all represent a net
operating loss.— Projections of cost effectiveness are made for
other throughputs and show that higher throughputs increase cost
effectiveness. Some of the recovery systems are capable of
recovering gasoline whose value is greater than the direct
operating cost.
-5-
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SECTION 3
CONCLUSIONS AND RECOMMENDATIONS
3.1 • CONCLUSIONS
A. Installing vapor emission controls systems on
gasoline barges introduces the potential for large
scale catastrophic fires and explosions of
significantly greater magnitude than exists in
present day gasoline-barge loading facilities.
B. Excluding safety considerations, application of any
of several technologies to destroy or capture
gasoline emissions is straightforward and presents
no unusual problems.
C. The control efficiencies of the vapor control
systems in descending order are; thermal
incineration, carbon adsorption, and refrigeration.
The overall control system efficiencies range from
86% to 97$ reduction in HC.
D. Capital costs for the control systems range from
$34.7,000 to $973,000. Capital costs for cases
using thermal incineration are significantly lower
than those using carbon adsorption or
refrigeration.
-6-
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E. Annualized costs for the control systems range from
$114,000 to $215,000. Those systems using inert
gas generators for their safety modules have the
lowest annualized costs, and the least costly
combination of safety and control modules is carbon
adsorption with inert gas generation.
F. Safety modules are the largest contributors to the
capital and annualized costs of the systems. From
64£ to 98% of the annualized costs and 2H% to 7056
of capital costs are contributed by the safety
modules.
G. Cost effectiveness, expressed in pounds of
hydrocarbons controlled per dollar of annualized
cost, range from 8.50 #HC/$ to 4.20 #HC/$. The
most cost effective systems use inert gas
generation for the safety module. The best of
these uses carbon adsorption for the control
module.
H. Cost effectiveness increases with increased gaso-
line throughput. At higher throughputs some
recovery schemes have a positive cash flow. At the
6 million barrels per year throughput used in the
study, all control cases result in a net operating
loss.
I. The cost and emissions evaluations developed in
this report are based on a hypothetical barge
terminal. A specific terminal has its own unique
design, throughput, operation, and location which
differ from the hypothetical one; therefore, the
-7-
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cost and emissions data generated in this report
cannot be applied directly to a specific terminal.
3.2 RECOMMENDATIONS
A. The design of any control system for emissions from
gasoline barges should provide means for rendering
the vapors non-explosive as they exit the barge
manifold.
B. A secondary, passive device should be installed at
the exit of the barge vapor manifold, and at other
critical locations in the system to prevent passage
of a deflageration or detonation should the primary
(active) system fail.
C. Hydraulic flash arresters should be used as the
secondary protection devices, and the type used in
acetylene service should be considered for use in
gasoline vapor service.
D. Any flash arrester chosen for use in an emission
control system should be tested and certified by an
independent laboratory prior to installation in a
commercial facility..
-8-
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SECTION 4
DISCUSSION
4.1 DESCRIPTION AND OPERATION OF A GASOLINE-BARGE LOADING.
TERMINAL AND A BARGE
Initially, this control technology study for gasoline
barge loading considers some of the operational and
physical features of the loading terminal. Although
there is no standard gasoline-barge loading facility,
and individual installations vary widely, there are
some common functions and details. The terminals are
normally multi-purpose facilities that are adjacent to,
or part of, a refinery, and usually they are owned by
;the oil company that owns the refinery. The one or
more docks from which barges are loaded may also be
used for ships, and in addition to gasoline, they are
often_ used to load other liquid petroleum products
including fuel oils, ke.rosene, naphtha, etc. It is not
uncommon for the docks to be used for unloading
petroleum materials - most often, crude oil from ships.
The docks usually use dedicated or segregated lines for
different services, and since individual lines serve a
particular product solely, the docks tend to be filled
with piping, valves, loading arms, and hoses. Since
space is at a premium, the docks generally have no
fixed machinery, but this is also a function of safety
considerations. The crowding is especially true at
older facilities where the available dock space has
-9-
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been used for facility expansions. The circumstances
just described are normal; however, some facilities do
have docks used exclusively for gasoline or barges.
The gasoline loading pumps are usually located in the
tank farm area. Generally, dedicated pumps, storage
tanks, and suction lines are used. Totalizing flow
meters may be used on the loading lines as part of an
inline blending station or custody transfer system. A
significant potential for contamination between leaded.
and unleaded gasoline stocks exists, and, therefore,
the storage and transfer facilities are usually
dedicated for each grade. The loading rates for barges
vary between individual operators but are usually in
the range of 3000 bph (2100 gpm) to 8000 bph (5600 gpra)
at design flow. The loading lines can be throttled to
a lower flow rate. Individual arrangements will vary
widely if the same pumps or dock manifolds are also
used for ship loading.
-The barges used in gasoline service are somewhat easier
to typify than the loading terminals. Barges used in
gasoline service are usually 20,000 bbl capacity and
have.^gight separate cargo compartments. The overall
dimensions of the barge are approximately 50 feet wide,
250 feet long and 13 feet deep.
The barges are most commonly in dedicated gasoline
service, and they are not ballasted, cleaned, or
degassed between -loadings. A common submerged manifold
is used for loading and unloading, and a series of
valves permits isolation of tanks along the manifold.
-10-
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The barge is equipped with two pumps for unloading
cargo and stripping the compartments. The pumps are
located on the rear deck and are driven by diesel
engines. A diesel fuel oil tank and a slops tank are
standard equipment. Pressure/vacuum relief valves are
mounted on a header.and configured to relieve either
single tanks or pairs of tanks.
The loading operation for barges is similar fo'r most
terminals. After the barge is moved into position at'
the dock, it is made fast by mooring lines. The cargo
loading hose is lifted into position (manually or by
hoist) and bolted both to the barge loading manifold
flange and the dock manifold flange. The barge opera-
tor prepares for loading by opening the proper valves
in the loading manifold and by opening the ullage caps
on the compartments to be filled. Opening the ullage
caps serves two purposes; it permits displacement of
vapor and thereby relieves pressure, and it allows
manual gauging of the cargo level in the tank. Vapor
release through the ullage caps, rather than through
the pressure/vacuum relief valve prevents a defective
valve from overpressurizing a barge compartment.
Although no flow rating for the valves has been
obtained, it appears that the valves are intended
primarily for breathing applications and are undersized
for loading applications. Manual gauging is
accomplished by inserting a calibrated rod into the
tank to determine the liquid level. The barge operator
inspects the liquid level visually throughout loading
operations and advises the onshore operator to reduce
the flow rate as the tank approaches the desired level.
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Initial filling is performed by gravity feed. All
valves along the flow path are opened allowing the
gasoline to flow into the barge. After ensuring that
gasoline is flowing to the correct tanks, the loading
pump is started. When the tank level approaches full,
the barge operator signals the onshore operator to
reduce the pumping rate and begin closing the valves.
Shutting down operations roust be handled slowly to
avoid hydraulic transient shock or "water hammer."
After the shore side valves are closed, the gasoline_
remaining in the hose is drained into the barge and the
hose is disconnected.
4.2 DISCUSSION OF CONTROL TECHNOLOGIES IN RELATION TO GASO-
LINE LOADING
As the introduction to this paper indicates, the three
different types of control technology being^studied
with respect to gasoline-barge loading are refrigera-
tion, carbon adsorption,•and thermal incineration. The
'..following paragraphs discuss the three methods indivi-
dually.
4.2.1 Carbon Adsorption
Carbon adsorption utilizes the affinity of activated
carbon for hydrocarbon compounds to remove gasoline
vapors from air. A typical carbon adsorption system
consists of two or more carbon adsorber beds and a
regeneration system for the carbon beds. (See Figure
U.2.1.) Two or more beds are necessary to maintain the
unit onstream because one bed is kept in adsorption
service while the other bed is being regenerated. The
number and size of beds are determined by the loading
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TREATED VAPOR
TO ATMOSPHERE
FL'AME
ARRE5TOR-
I
M
OJ
RECYCLE
CARBON
"ADSORPTION
(—,M
MOV
LIQUID RING
VACUUM PUMP
SEPARATOR
, i MOV MOV
-§o-
INLET
GASOLINE VAPOR
&~
GASOLINE
WAT
)LIN
ER
GASOLINE
COOLER
FROM
STORAGE
GASOLINE
STORAGE
PUMP
> TO
!STOPAGE
GASOLINE RETURN
PDWP
Figure 4.2.1 Carbon Adsorption Module
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period, the time required for regeneration, and the
working capacity of the activated carbon under the
operating conditions. Regeneration (in situ) can be
performed by vacuum or steam or both. Each of these
methods relies on elevating the vapor pressure of the
adsorbed hydrocarbons relative to the absolute pressure
in the void space at the -bed. The gasoline vapors
desorb from the carbon particles into the void space
where they are removed.
In the vacuum regeneration system (Figure U.2.1) the
carbon bed is placed under a high vacuum, approximately
25mm Hg, by a liquid-ring-seal vacuum pump. Vacuum
regeneration is especially useful where temperature
limitations exist due to polymerization or safety
problems. The gasoline vapor desorbed and evacuated is
reclaimed by condensation or adsorption into gasoline
liquid. After desorption (which regenerates the bed)
the bed is returned to service. Advantages of vacuum
regeneration include .an uncontaminated recovery
^product, low operating temperature, and fewer utility
requirements.
Steam regeneration uses direct steam contact with
carbon to heat the carbon and desorb gasoline vapors.
The flow of steam through the bed carries the gasoline
vapor out for reclamation. The purged steam and
gasoline vapors are condensed by cooling and the
gasoline liquid is decanted and recovered. After steam
desorption and purging, the beds are cooled before
being returned to service. Advantages of steam
regeneration include higher working capacity and
increased desorption of heavier compounds.
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Hybrid regeneration systems utilizing both vacuum and
indirect steam heating have been designed for carbon
adsorption systems. These techniques permit additional
flexibility in the types of hydrocarbons treated by
combining the advantages of steam and vacuum.
This section of the barge loading study presumes the
use of a carbon adsorption system incorporating vacuum
regeneration and adsorption at atmospheric pressure.
The system was selected because it has been used by
several operators for gasoline-truck loading, and
because records of the operating results are available.
Approximately 10 units in the United States are now in
service for gasoline-truck, loading, and they have
design flowrates of up to 6000 gpm.
NOTE
For convenience, flow rates of vapors dis-
placed by liquid tank will be given in gpra
rather than the more familiar ft3/min.
The efficiency of recovery for carbon adsorption is
high; as much as 99% recovery in some commercial
installations.
The estimated costs obtained from the manufacturer for
the two units considered in the study are $335,000 and
$229,000 depending on the safety technique used with
the system. The vendor package is complete except that
utility connections must be made prior to operation.
The carbon adsorber beds, vacuum pump, gasoline trans-
fer pumps, adsorber-separator, and the associated
piping and instruments are included, and all are skid
mounted. The package does not include any supplemental
safety devices although explosion proof electrical
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construction is used. The danger of spark generation
in the vacuum pump is minimal and an over-rich condi-
tion is maintained. Hot spots in the adsorber beds are
unlikely because of the working capacity used, the type
of components adsorbed, and the frequency of bed
cycling.
4.2.2 Refrigeration The refrigeration system studied utilizes
two cooling stages operating at approximate
temperatures of 35° F and -100° F. (Refer to Figure.
4.2.2.) The principle of operation is simple
condensation at atmospheric pressure caused by
refrigerating the vapor mixture to temperatures below
the boiling points of the h-ydrocarbon components.
Since gasoline is a mixture of compounds, each with a
unique vapor pressure- temperature curve, cooling to
any given temperature will condense components that
exist as liquids at that temperature and atmospheric
pressure and only to the extent permitted by
vapor-liquid equilibrium'.
Of the three vapor control technologies considered in
this study, refrigeration is most likely to be impacted
by the various mixtures of gasoline. For instance, one
recent, detailed analysis of a full-range, motor gaso-
line lists over 200 different compounds with a range of
boiling points from -43° F, to 421° F, all of which, of
course, would condense in the -100° F environment of
the refrigeration system. On the other hand, gasoline-
loading vapor analyses by two oil refineries showed a
significant difference in vapor composition for gaso-
line. One refiner gave the volume percentage of G and
C2 compounds in the vapor at ambient temperatures as
0.02$ while another gave 3.38$ as the C and C2
composition at ambient temperatures.
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CONDENSER
AIR
PRECOOLER
J/\l
CONDENSER
AIR
n
J/NL .
PRECOOLER
REFRIGERATION
UNIT n
ELECTRICAL
UTILITY
HOOK-UP
/
LOW
TEMPERATURE
REFRIGERATION
SYSTEM
RECOVERED
VAPOR
FROM BARGE
TREATED
VAPOR TO
ATMOSPHERE
COOLING
RECOVERY
SECTION
VAPOR
CONDENSER
CONDENSED
! GASOLINE
TO RECYCLE
CONDENSED
'WATER TO
DISPOSAL
Figure 4.2.2 Refrigeration Vapor Recovery Module
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NOTE
EPA does not consider methane and ethane
emissions a problem since they do not enter
into the reaction that produces smog.
While the refiners' analyses may not be significant
from an environmental protection point-of-view, they
are important with respect to this basic study of vapor
control by refrigeration because C and C compounds
(primarily methane and ethane) are unlikely to be
removed to any significant degree by cooling to -100°F.
The normal boiling points of methane and ethane are
-259°F and -127°F respectively. However, a small
amount will be absorbed into heavier compounds and thus
removed. In fact, overall recovery efficiencies of 94/6
have been observed. In the first or precooler stage,
the inlet vapors are cooled to 3M°F which allows high
removal of water vapor as well as the higher boiling
hydrocarbon components. In the next step, vapors are
introduced to the low-temperature vapor condenser,
which operates between -80°F and -115°F, where
additional condensible HC vapors are removed. The
condensed liquids are separated into hydrocarbon and
water components by decanting. The recovered gasoline
from the condenser is returned to storage, the water is
sent to the wastewater system, and the non-recoverable
HC and air are vented to the atmosphere. The
refrigeration system uses a cooling recovery section
for increased efficiency. Incoming vapors to the
condenser pass through the cooling recovery section and
are cooled by heat exchange with the exiting
non-recoverable vapors. The exiting vapors warm to
approximately 75°F during this process step.
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A warm brine system is included in the equipment for
periodic defrosting of the low temperature vapor con-
denser section. The defrosting operation is performed
during non-loading periods and requires one to two
hours. Applications which require dual condensers are
those in continuous service or those which operate in
high humidity and build up ice rapidly. The condensers
are cycled between defrost and operating modes. The
models used for evaluation and costing in this study
include dual condensers.
Gasoline vapor recovery by refrigeration for truck
loading operations has been accepted by some oil
companies and approximately 70 units- are now in use.
The price estimates, obtained from the manufacturer's
local representative, for the two refrigeration vapor
recovery units described in the study are $300,000
each. The vendor package is complete except that
utility connections must be made prior to operation.
The skid mounted package contains the cascade
refrigeration units, defrost system, condensers,
separator, recovered gasoline pump, and the piping and
instruments. The unit is constructed to meet
applicable explosion proof codes, but it does not
normally include any additional safety devices such as
flame arreators. However, the precooler and vapor
condense-r coils (Operating at approximately -100°F)
could be regarded as wetted flame arresters.
4.2.3 Thermal Incineration
Thermal incineration (Figure 4.2.3) disposes of
gasoline vapors by burning rather than by product
-19-
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to
o
i
TREATED VAPOR
TO ATMOSPHERE
PILOT
BURNER
FUEL
V-
VAPOR
BURNER
I
AIR DAMPER
STACK
MAIN BURNER
, INLET GASOLINE
VAPOR
WATER SEAL-
Figure 4.2.3 Thermal Incinerator Module
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recovery methods. It provides the simplest and most
direct control technology for gasoline and other
hydrocarbon vapors. A typical unit as provided by one
manufacturer is described in this study. The collected
gasoline vapors are injected into the combustion
chamber of the incinerator through a burner manifold.
A temperature of approximately 1500°F is maintained in
the chamber.
The residence time in the chamber is on the order of
one second. Pilot burners provide ignition and main
burners (supplementally fueled) are used, as necessary,
to maintain the proper combustion temperature.
Automatic air dampers admit combustion air and are set
on temperature control. The efficiency of thermal
incineration is higher than that of competing
technologies. Over 99.9% of the hydrocarbon vapors are
converted to non-hydrocarbon combustion products such
as CO or CO. With little or no incinerator modifica-
tions, similar results are obtained for a wide range of
hydrocarbon compounds, and, of course, this is one of
thermal incineration's chief advantages. Thermal in-
cinerators are available from several manufacturers,
and they have been installed by a number of gasoline-
truck loading terminal operators. The estimated cost
given by one manufacturer of an incinerator with a
design flow~of 5000 gpm, is $64,000. Their estimate of
a duplex'unit capable of 10,000 gpm is $128,000. The
price includes the incinerator, monitoring devices, and
protective water seals. The vendor supplied package
requires only utility connections for operation.
-21-
-------
The incinerator operates at atmospheric pressure. The
total pressure drop across the unit is approximately
12" H 0, and it is due almost entirely to the water
seals on the vapor inlet. The thermal incinerators
investigated for the report include several safety
features:
1) As previously mentioned, for greater reliability,
two water seals are installed in the vapor inlet.
2) An interlock for low-water seal level is used to
prevent startup.
3) Ultraviolet radiation detectors are incorporated
into the pilot and main burner interlock controls.
4) Emergency shutdown is used to prevent damage by
excessive temperature.
5) The incinerator shutdown and interlock systems have
a safety interface with the vapor collection and
gasoline loading systems.
6) The incinerator burners themselves are designed
with quenching slots to prevent flashback in the
combustible vapor stream.
4.3 GENERAL DISCUSSION OF SAFETY TECHNOLOGY
The two major safety problems associated with gasoline
barges and vapor control systems are fire (and/or
explosion) and overfilling.
-22-
-------
The following study considers safety problems as they
exist and as they would be if vapor control and safety
technology were used.
4.3.1 Fire and Explosion
With the current gasoline loading system, it is routine
for fuel and air, two of the three elements required to
initiate a fire or explosion, to be present around the
barges. They are there because the heavier-than-air
gasoline vapors displace, the air near the deck of the
barge. The third element, ignition, is a constant
danger since the potential for static electrical and
friction sparks., improper or malfunctioning electrical
equipment, unauthorized smoking, operating tug boats,
etc., can never be controlled absolutely. Until now,
fire prevention philosophy has been to accept the
presence of combustible mixtures both inside and
outside of the barge, and to concentrate on eliminating
ignition sources while hoping the air currents are
sufficient to disperse the vapors and keep them too
lean to ignite.
Addition of a vapor control system would eliminate one
problem since vapors would no longer be released near
deck level. However, a new problem caused by connect-
ing an on-shore control facility to the barge - with
both containing explosive mixtures - would be created.
Since the facilities would be connected, new ignition
sources would be created. Effectively, there would be
a closed system, and a chain ignition could occur in
either direction. Ignition from the shore to the barge
would be of most concern since blowing up the barge
would have the more disasterous consequence. Safety
-23-
-------
problems attendant to this closed system are more
severe than the safety problems with the present system
since ignition using the current loading technique
should, at worst, cause a flash fire on the deck of the
barge.
Potential ignition sources in the onshore equipment
include rotating parts, static electricity, tramp metal
in lines, and external fires.
The philosophy adopted in this study for protection of
barges and vapor control systems from fire/explosion
utilizes two systems employed together. These systems
are:
1) A primary (active) system that renders the vapors
emitted from the barge non-flammable by one of
three means; - ~
a) Dilution with air,
b) Replacement or reduction of air by fuel gas,
N , or combustion gases (also called blanketing
or inerting) ,
c) Saturation of the vapors with gasoline.
2) A secondary (passive) system uses a single device
that would preclude allowing a flame front (defla-
gration) or a detonation to pass either to the
barge or to the dockside facility. Both components
must be used in the overall system. The primary
system, no matter how well designed, can have
-24-
-------
equipment fail and allow exploding vapors to enter
the vapor control system. Should an ignition occur
under these conditions, the secondary system must
be installed to prevent the flame from reaching the
barge and creating a major catastrophe.
U.3.1.1 Primary (Active) System.- The primary system protects
the barge loading area from fire or explosion by alter-
ing the barge vapors to make them non-combustible. The
principles of the three active fire prevention tech-
niques are discussed in the following paragraphs.
A. Dilution. - Dilution of the gasoline vapors
recovered from the barge constitutes the simplest
technique for rendering the mixture non-flammable.
Dilution is accomplished by adding and mixing
enough air with the vapors to reduce the HC
concentration below the lower explosion limit (LEL)
(approximately 1.4? gasoline by volume). The
initial HC concentration determines the amount of
dilution required.
To determine the volume of air required for dilut-
ing a given HC concentration, the maximum concen-
tration by volume for a given set of conditions is
established, and the volume of air required to
reduce this to 1.4? by volume is calculated. The
theoretical maximum HC concentration is the ratio
of the gasoline true vapor pressure (TVP) to the
absolute (atmospheric) pressure of the system. For
a TVP of 7.4 psia, the theoretical maximum is 50.4?
HC by volume. To reduce the HC concentration to
the LEL, (ratio of HC to LEL or 50.4:1.4)
-25-
-------
the volume of air required is 35 additional volumes
of air per volume of initial mixture. Allowing a
safety factor of four (25% LEL) the required air
volume is 143 times the initial volume. Therefore,
the maximum efficient dilution air flow rate is 143
times the gasoline vapor flow rate.
B. Inertion. - Another means of rendering the mixtures
non-flammable is by inertion. This technique uses
gases such as N2, C02> treated flue gases, or fuel
gas, to replace air in the barge vapors and reduce
the percentage of oxygen present. Depending on the
type of inert gas used and the HC mixture, the
maximum oxygen concentration'allowable in the
mixture is approximately 12-15? by volume. Inert
gas can be introduced to the gasoline vapors by
several methods. The preferred method is to admit
inert gas into the barge as the liquid gasoline is
unloaded by the receiver. Theoretically, this pre-
cludes an explosive mixture being encountered. As
the gasoline is unloaded, the air that would norm-
ally enter the barge and create an explosive mix-
ture is replaced by the inert gas. During unload-
ing and the return transit, gasoline would evapo-
rate as it normally does, but it would do so in an
essentially inert atmosphere. When the barge is
reloaded with gasoline the non-explosive mixture is
displaced into the vapor collection-treatment
system. The amount of vapor that is treated is at
a minimum because no other gases are added.
C. Saturation. - Saturation of hydrocarbon vapors
renders the mixtures non-flammable by enriching the
-26-
-------
HC concentration of the stream significantly above
the upper explosion limit. The upper explosion
limit is about 8.4$, and the saturation concentra-
tion (which varies with temperature) ranges from 30
to 50$ for normal temperatures. The vapors are
saturated by passing them through a vessel, speci-
fically designed for this purpose, where gasoline
liquid is sprayed into the stream. As the gasoline
spray evaporates, the HC concentration of the
stream increases.
M.3.1.2 Secondary (Passive) Systems.- Several secondary
devices are available to prevent flame or flashback
propagation in the vapor control system. The devices
are based on one of two principles although some may
utilize both. One device uses metal tubes or plates
which offer a large surface area to the vapor flow.
The principle is to provide a large metal surface which
acts as a heat sink and quenchs the fire preventing its
propagation. The other type uses a liquid seal leg to
disrupt the continuous vapor flow and prevent flame
propagation. A variation of the liquid seal type has
been used to contain and stop detonations in acetylene
plants. Their effectiveness was demonstrated in a plant
accident where a large detonation, between acetylene
plants, in a pipeline was contained (Refer to Trade
Journal #1)-. A demonstration of the usefulness in
gasoline "vapor service is warranted. This device is
shown in Figure 4.3.1. Several secondary protection
devices are used to isolate various portions of the
system (e.g., the barge is separated from the active
portion of the safety module and both will be isolated
from the vapor control module) . A flame arrester is
also required for the vent stack of the carbon
adsorption and refrigeratio.n vapor recovery units
-27-
-------
LIQUID
MAKEUP
CHECK
VALVE
»— INLET
OUTLET
SCHEDULE 80
THREE-WAY
VALVE
DRAIN
Figure 4.3.1 Hydraulic Flash Arrestor
-28-
-------
because these systems can emit flammable vapors.
M.3.2 Barge Overfilling
The present method used to load barges requires one or
more open hatches per compartment for the operator to
gauge liquid levels by direct sight. While this method
is extremely simple and reliable, it poses emission and
safety problems. Vapor control for gasoline barges
would require discontinuation of this system and use of
a closed gauging system. Since the consequences of
overflowing a compartment are severe, a combination of
a gauging system and warning devices to indicate
excessive liquid levels is warranted. A direct reading
level indicator utilizing a stainless steel tape and
float (housed in a stilling well) are used. (Refer to
Figures 4.3.2 and 4.3.3.) High level floats with
externally mounted switches provide the warning and
they could be used to shutdown the systems^ As an
alternate to the level indicator, a transparent window
for an observation port could be used for direct
sighting, provided lighting and a method to prevent
obscuring the level are furnished.
4.4 APPLICATIONS OF SAFETY AND CONTROL TECHNOLOGIES
There are fifteen combinations of safety and control
modules available when studying the three control
technologies and the five safety technologies. Refer
to Figures 4.2.1, 4.2.2, and 4.2.3 for the carbon
'adsorption, refrigeration, and thermal incineration
controls, and to Figures 4.4.2, 4.4.3, 4.4.4, and 4.4.5
for the safety technologies using dilution, saturation,
and inerting with three different gases. Also refer to
Figure 4.4.1 for the overview or system block diagram.
-29-
-------
MODIFIED ULLAGE
CAP
o
I
PRESSURE VACUUM
RELIEF VALVE
ULLAGE
CAP
(OPENED DURING")
v LOADING ^
RELIEF HEADER
CONNECTS TWO
CARGO COMPARTMENTS
WARNING
DEVICES
. VAPOR
tOMPARTMENT
FLAME ARRESTOR
XVVAPOR COLLECTION
/ MANIFOLD
EXTEND TO
WITHIN 6"
OF BOTTOM
MODIFIED ULLAGE
/CAP INTERNALLY
' LIGHTED TRANS-
PARENT COVERED
INSPECTION PORT
FIXED CALIBRATED
GUAGEING STICK
f DUAL (REDUNDANT) LEVEL
L— SWltCHES AT DESIGN
MAXIMUM LIQUID LEVEL
FXIST. BARGE VAPOR
SYSTEM (TYPJ
MODIFIED BARGE VAPOR
SYSTEM
Figure 4.3.2 Barge Modifications
-------
PV VALVE SIZED TO PROTECT
ALL TANKS DURING LOADING
i
U)
M
I ,
EACH PV VALVE PROTECTS PAIR OF
TANKS SIZED FOR BREATHING ONLY
FUEL OIL
. AND
SLOP TANKS
»CARGO PUMPS
PUMP "ENGINES
Figure 4.3.3 Barge Vapor Collection Manifold
-------
A number of these combinations can be eliminated from
analysis because of incompatability between the control
and safety modules for technical or economic reasons.
The dilution scheme is incompatible with carbon
adsorption or refrigeration due to the high cost of the
control equipment and low removal efficiencies.
Enrichment of the barge vapors with fuel gas is also
incompatible with carbon adsorption or refrigeration
because virtually all of the light HC components would
be emitted to the atmosphere at an economic loss.
Eleven cases have been investigated. Thermal incinera-
tion is used with all five safety modules. Carbon
adsorption and refrigeration are used with saturation,
with inerting using N2> and with inerting using an
inert gas generator. The inert gas generator used in
the study burns natural gas under carefully controlled
conditions to produce an oxygen-free pro-duct of
scrubbed and cooled combusion gases.
The predicted exit vapor compositions from each of the
safety modules is given in TABLE 4.4.1. Compositions
are given for the three different initial HC concentra-
tions used (5%, 18$, and 50%). These compositions
represent the vapors that are received by the treatment
units.
The control efficiencies and economics that are deve-
loped in this report are based on an initial HC con-
centration of 1856. The design gasoline loading rate is
6000 barrels per hour (bbl/hr) or 4200 gpm. The annual
gasoline throughput for the barge terminal is six
million barrels per year. It is assumed that 300
barges, each 20,000 _b.bl capacity, are loaded each year.
-32-
-------
U)
I
TREATED
VAPOR
VAPOR
"CONTROL
.MODULE
GASOLINE
.STORAGE
TANKS
GASOLINE
PUMP HOUSE
Figure 4.4.1 Loading and Collection System Layout
-------
7.7 ppm
50.4 ppm
168 ppm
123.9 ppm
99.96$
26.6 p pm
182 ppm
605.5 ppm
- 445.9 ppm
99.87$
.01$
.05$
.17$
.12$
99.65$
TABLE 4.4.1
PREDICTED VAPOR COMPOSITIONS
Safety Technique: Dilution with air to maintain 25$ L.E.L.
(= .35% total HC by volume) @ 50$ initial
concentration
Design Flow Rate = 353,000 GPM (47,000 ACFM)
Vapor Analyses for Design
Initial Total HC 5% 18$ 50$
Components by Volume
c, +ca
C3
s
C + Heavier
Air
Additional Volumes of
Air Added 141.86 141.86 141.86
Safety Technique: Fuel Gas is used to blanket the system and
maintain 50$ fuel gas in the vapors
Design Flow Rate = 9900 GPM (1325 ACFM)
Initial Total HC 5$ 18$ 50$
Components ($ by Volume)
C + C _ .06 .19 .53
C .36- 1.30 3.61
C3 1.20 4.33 12.10
C and Heavier .89 3-19 8.90
Fuel Gas* 50 50 50
0 . 9.98 8.6 5.25
2
Additional Volumes of
F.G. Added 1.0 1.0 1.0
*Fuel Gas can be assumed to be 100$
-34-
-------
.66
4.32
14.4
10.62
30
.66
4.32 ,
14.4
10.62.
30
1.06
7.22
24.03
17.70
50*
TABLE 4.4.1 (Cont)
PREDICTED VAPOR COMPOSITIONS
Safety Technique: Saturate vapors to 30% HC
Design Flow Rate = 5900 GPM (8'00 ACFM)
Vapor Analysis for Design
initial Total HC 5% 18% 50%
Components (%)
C3
C4
Cj. and Heavier
Final Total HC
Volume Increase due to
Gasoline Saturation . 36% 17%
*_Fully Saturated
Safety Technique: Inert Gas Blanket
Design Flow Rate = 4950 GPM (660 ACFM)
Vapor Analysis for Design
Components (%)""
Cl + C2
C3
C4
C and Heavier
Inerts
O.
"5%
.11
.72
2.40
1.77
95
0
18%
.38
2.60
.8.65
6.37
82
0
50%
1.06
7.22
24.03
17.70
50
0
-35-
-------
4.4.1 Thermal Incineration by Dilution
. (Figures 4.2.3 and 4.4.2)
A dilution system reduces the HC concentration from the
initial concentration (as high as 50%) to 25% L.E.L.
(.35% HC) . Dilution is accomplished using a 47,000 CFM
blower which would- be 10056 spared. The vapors are
diluted upstream of the blower, a potential spark
source. The barge vapors are introduced into the suc-
tion side of the blower at 50% of the maximum loading
rate, which is 2100 gpm. This step increases the load-"
ing time and was taken to reduce the size and cost of
the system. This safety module is simple to operate
and extremely reliable. However, it is compatible only
with thermal incineration. The diluted vapors are
transferred to the thermal incinerator and raised in
temperature using supplementally fueled burners. In
the event of incinerator failure, the vapors are safely
released to atmosphere since they are not flammable.
Interlocks are provided on the incinerator to prevent
operation if the dilution system fails. An emergency
"shutdown for loading pumps, in case of dilution system
failure, is desirable. Overall system simplicity
insures very high reliability. Disadvantages of this
system are the high fuel usage necessary to burn the
lean vapors and the large flowrate which necessitates
large and expensive equipment.
4.4.2 Thermal Incineration with Saturation
(Figures 4.2.3 and 4.4.3)
Vapors displaced from the barge go directly to the
saturator tower. There they are contacted with
-36-
-------
6" VAPOR RETURN LINE
6 MARINE .
LOADING 1^
HOSE
I
to
WEATHER CAP
*«t
*tn
i
\
n^ ,
UJ
cr
CO
^bin .. ff
J, VV rO^1 — —
1 V \
[ I
\ /
LJ
o:
CO
" ' \ ^^^-36" DILUTION AIRLINE
^ '» n AMF
^RE^r?r°N rARRESTOR-\ DILUTED VAPORS
ORIFICE / \ ^ TO VAPOR
J.^yv ° ^ rnr\|TRni
A' . UNIT
5 \ BLOWERS
g V. 47000 ACFM
(2-!00^ UNITS)
i
i
i
!£ " FROM
DX] » i W*vl* / \ bw^ULIlNL
GASOLINE ( *7 "5blORAGE
i— CONTROL 2±1 . ..AniMr TANKS
. , . . . ,r |T i OAl J N(i
\/Al VF \_ i_w'-*L-"iNvj
v L PUMP
*:
0
Q
Figure 4.4.2 Dilution Module
-------
r
Ul
CD
1
C
I
\
•-•
l
\ 6" MARINE
v LOAD ING
HOSE
1
I (PC)
1 1 MP
/ LJ
/ . r,
o:
CD
/
"1
k Y J
hi
A SATURATED VAPOR
6" r~\ V3 — o — (sj— HTO VAPOR
RI n\ /F& yrr CONTROL CON i ROL UNI i
C-)l_xy WC.r\.-.J S i "Lt \/Al \/P
OvJv-' '^\^i 1 1 JTT-
(M^T°C%) ! p- / ! LOU PRESSURE
\UNITS / ! _, <: Ji ' irTEAM
^ CONTROL VA^VE j ," ^ CONDENSATE
c "\ Y -\ ' : ' KLIUHN
/" "S. YiWAVxnWihS? 1 , 'J'^Sw
(FIC)
6«L" i ii
/-*-
SATURATIONy Q_
TOWER .
_t_
f^* i ' f^Mji
PQ* 1 )^ U-*vT*
CONTRC
VALVE
*:
o
Q
« ' >; < \
_ , ,A> y 4 .. -.(Fc INO Fl D\J
w X^^^ — T \r-yiMU TLUW (^LQC.,^
p ^^HFJvrER'^CQN"^01-
Q76MMBTU/HR. VALVE !
"7^ CLOSE
. vL%bPENl
rfe) r
VLLSTOP,"
(^r\ r RE^ipri i|_ATinM
V^X H — PUMP
0 l5 GPM |" GASOLINE
r-l-l - ' < TDr>M
MAKE-UP STORAGE
VALVE
INCLINE
\\ f _T\ ^ FROM
XX STORAGE
LOADING TANKS
PUMP
Figure 4.4,3 Saturation Module
-------
gasoline which raises the concentration of HC in the
* vapors well above the upper explosion limit (UEL) . The
gasoline is recirculated by a small pump through a
steam heated heat exchanger to maintain the gasoline at
the temperature required for adequate vaporization. A
demister on the outlet removes entrained droplets.
Level switches control the gasoline make-up valve and
prevent the pump from operating dry. The steam control
valve is set on temperature control with a flowswitch
override. Liquid gasoline flow rate can be varied with
the vapor flow rate by means of a fixed ratio control-1"
ler. The vapors are transported by blower to the ther-
mal incinerator. Combustion air is added in the incin-
erator because the vapors are too_ rich for efficient
direct combustion. However, no supplemental fuel is
necessary and only the pilot burners are used to
maintain combustion. Upon failure of the saturator,
the thermal incinerator is automatically prevented from
operating. A disadvantage of a saturator is its
relative complexity compared to the other safety
r.modules, and this reduces its overall reliability.
4.4.3- Thermal Incineration with Fuel Gas Blanketing
(Figures U.2.3 and 4.4.U)
Fuel gas blanketing of the barge vapors is accomplished
by mixing equal volumes of fuel gas and vapors which
cause blanketed vapors to be 5056 fuel gas and too rich
to burn. Assuming the fuel gas is mostly methane, the
UEL of. which is 13.5$, a safety factor of 4 is used.
The fuel gas blanketing system resembles the dilution
-39-
-------
4' FUEL GAS LINE
r FROM REFINERY
O
1
i
^
6 MARINE LOADING HOSE
y ^
f
\
i
V '
r
k
\
CHECK
VALVE
_^
NO FLOW !
STOP i
I
8% .A-
BLOWERS
(2-lOO?o
rZilT"" ^J_
r—tXll ^^ 1
LU
1 n
/ a
/ <
/ m
/NJW \ \ . I/ M
CONTROL
g VALVE
0
Q
FUEL GAS
REGULATOR
~i
RATIO
, W/MIN.
r" P
— Q— 6y— — o
CONTROL
VALVE
1325 ACFM
UNITS)
i
/" -^N
LOADING
PUMP
3 FUEL GAS
t
CONTROL . '
FLOW BLANKETE
— [s}-*$ TO VAPOR
UNIT
, GASOLINE
' J STORAbh
SYSTLM
D VAPORS
CONTROL
FROM
TANKS
Figure 4.4.4 Fuel Gas Blanketing Module
-------
module closely except that fuel gas is used instead of
dilution air.
A fuel gas regulator maintains the flow of fuel gas at
the proper pressure and a restriction orifice prevents
the barge vapor flow rate from exceeding a
predetermined maximum. The over-rich gas is sent to
the incinerator by a blower where combustion air is
added. No supplemental fuel is necessary and only the
pilot burners are necessary. The reliability is almost-
the same as the dilution system and the same interlocks
and safeguards apply.
Thermal Incineration with N g-Blanke'ting
(Figures 4.2.3 and 4.4.5)
The proposed N2 blanketing scheme varies from the
earlier safety schemes in that the barge vapors are
made safe at the barge unloading terminal. This is
done by introducing the N2 gas as the barge is emptied,
"and the gas replaces the air that would normally be
allowed to enter the barge. The N2 gas is stored as a
liquid and vaporized as necessary in an ambient air
vaporizer. When the barge is loaded, the expelled
vapors contain a mixture of gasoline and N2 which is
non-flammable. These vapors are transported by blower
to the incinerator. Since the average HC concentration
(1856) is above the UEL, only combustion air and pilot
burners are necessary for incineration.
The pressure vacuum relief valves must be operating
correctly to prevent excess air infiltration from
forming an explosive mixture in the barge. Sampling
-41-
-------
6" MARINE LOADING HQSE
HtXH-
INERT GAS LINE
'4' /
UJ
N2 REGULATOR VALVE
o
o
Q
AMBIENT TEMPERATURE L|QU|D N DEWAR
VAPORIZER STORAGE TANK.
6' MARINE LOADING HOSE
GASOLINE UNLOADING SCHEME
TO GASOLINE
STORAGE
6 MARINE LOADING HOSE
BLOWERS 700 ACFM
(2-IOO;0 UNITS)tf&
^l^•
INERTED VAPOR
) •$ TO VAPOR
CONTROL UNIT
GASOLINE U-4*-
CONTROL 2r^
VALVE LOADING
PUMP
_e GASOLINE FROM
"^ STORAGE TANKS
GASOLINE LOADING SCHEME
Figure 4.4.5 N2 Blanketing Module
-------
the barge vapors might be required before gasoline
loading is started. N2blanketing is simple, and its
reliability is high.
4.4.5 Thermal Incineration with Inert Gas Generation
(Figures 4.2.3 and 4.4.5)
Except for using an inert gas generator rather than
liquid N2 as the blanketing medium, this scheme is
similar to the N2 blanketing scheme. The inert gas_
generator supplies scrubbed and cooled combustion gas
to the barge. An inert gas generator burns a stoichio-
metric mixture of fuel (gas or oil) and air carefully
to obtain a gas with virtua-lly no free oxygen. The
inert gas generator is more complex than the N2 storage
and vaporizer system and, therefore, is considered to
be somewhat less reliable - but not enough so to
warrant its rejection. The system offers many of the
same advantages as N 2 gas and is equally compatible
with the control equipment.
4.4.6 Carbon Adsorption with Saturation
(Figures 4.2.1 and 4.4.3)
The saturation module operation is discussed in detail
in Section 4.4.2. The carbon adsorption system
receives the saturated mixture downstream of the
blowers. The effect of saturation is to increase the
removal efficiency of the carbon adsorption unit;
however, due to -the higher HC loading, the beds must be
sized larger than they would if receiving vapors
directly from the barge. Switching from the adsorbing
mode to the regenerating mode is initiated automati-
cally by a timer. All valves are actuated automati-
cally. The desorbed vapors are passed through a
-43-
-------
adsorbing/condensation separator column of cool
• gasoline from storage. Condensed water is decanted in
a separator. The water is sent to sewer for subsequent
treatment and disposal. The recovered gasoline product
is returned to storage. Because no segregation of
vapors from leaded and unleaded stocks is proposed, the
coolant gasoline is leaded to prevent contamination of
unleaded gasoline. Reliability for this case is lower
than average for the cases studied due to the
complexity. It is possible for the exit vapors to be
flammable, even though the influent vapors are
over-rich. To prevent a fire that originates at the
vent from propagating, flame arresters and careful
positioning of the vent is necessary-.
Carbon Adsorption with N 2 or Inert Gas Generator
(Figures 4.2.1 and 4.4.5)
These cases are sufficiently similar that they can be
discussed together. The•operations of the N2 module
and inert gas generator module are discussed in 4.4.4
and 4.4.5 respectively. The carbon adsorption system
operates in the same way as that used with saturation.
However, due to the lesser HC loading, the carbon
requirements are lower. The possibility for flammable
exit gases is reduced by the presence of N 2 or inert
gas. With respect to reliability relative to the other
systems, this system ranks about average.
Refrigeration with Saturation
(Figures 4.2.2 and 4.4.3)
Operation of the saturation module has been described
in Section 4.4.2. The refrigeration unit is designed
-44-
-------
. to operate automatically without operator attention.
Condensed water and HC are collected and separated.
Recovered gasoline is sent to leaded gasoline storage
tanks to prevent -contamination. The refrigeration
system also handles defrosting automatically. It is
possible that the ex-it vapors will be in the flammable
range. Therefore, flame arresters and proper placement
of the vent is mandatory. The overall complexity of
this case is among the highest studied and for this
reason reliability is affected.
4.4.9 Refrigeration with N? or Inert Gas Generator
(Figures 4.2.2 and 4.4.5)
The operation of the N 2 blanketing and inert gas gener-
ators is discussed in Sections 4.4.4 and 4.4.5. Due to
their similarity they can be discussed together. The
type of refrigeration system for use with these two
safety modules need not be changed from that used with
.saturation because they are designed for saturated
v'apors. The possibility of flammable exit vapors is
low due to the presence of N2 or inert gas. Based on
the degree of complexity for the overall systems, the
reliability is about average for the cases studied.
4.4.10 Other Design Considerations
The features of individual gasoline barge terminals are
significantly different than those of the hypothetical
terminal. These differences would, of course, change
the specific design conditions. For example, if the
cargo services for the barge were switched from gaso-
line to diesel oil, gasoline vapors (the arrival
-45-
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component) would be displaced when diesel was loaded.
Although the HC concentration of the evolved vapors
would be lower than for gasoline loading, they would
still present significant safety and emissions
problems. It would, therefore, be desirable to control
this mixture of gasoline and diesel vapors. However,
if gasoline and diesel were loaded at separate docks,
the gasoline barge vapor control system would have to
serve the diesel oil loading dock. This is not a
design consideration used on the model and would affect.
the conclusions as well as the design and operation of
the control facility.
Some means for handling condensed and entrained liquid
hydrocarbons within the vapor collection system is
necessary. Condensed HC is a problem particularly with
respect to the saturation and inertion safety modules,
because the lines are full of vapors that condense due
to nocturnal cooling when the system is shut down.
This problem can be solved by sloping the vapor collec-
T..tion lines to a liquid knock-out drum. The condensed
liquids will drain to the drum and can be removed
periodically. Another solution for the condensation
problem is to purge the system with air by continuing
to operate the cont.rol system after loading is
completed.
U.5 EMISSIONS AND CONTROL EFFICIENCIES
4.5.1 Primary Emissions
A hypothetical, non-explosive composition for vapors
emitted from the barges is used in this study. The
-46-
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composition of the stream is altered by various sa.fety
modules to insure that explosive mixtures are never
sent to the vapor recovery system. Composition of the
unaltered vapor as it leaves the barge is shown in
TABLE 4.5.1. The hydrocarbon vapor has a concentration
of 185& by volume, which is equivalent to an emission
factor of 4#H.C/1000 gallons of gasoline filled,
assuming an average molecular weight of 66 #/#mole.
These figures are based on test data developed by Exxon
and as reported in EPA-450/3-76-038a, page 127. For
full loading "of a 20,000 bbl capacity barge, the HC
loss, therefore, is 3360 pounds when the vapors are
allowed to vent directly to atmosphere. Since this is
the method by which barge vap.ors are being handled, the
3360 pounds HC loss per barge loading is the emission
quantity used for the base case. For an annual rate of
300 barges, the predicted loss is 1,008,000 pounds of
hydrocarbons per year for the hypothetical terminal.
The stated efficiencies -for the vapor control modules
:were obtained from the equipment manufacturers, or
their representatives, for optimum operation under the
vapor conditions given to them. These vapor conditions
are listed in TABLE 4.5.2.
TABLE 4.5.3 describes the manufacturers' predicted
efficiencies. For comparison, a short survey of EPA
test reports of tank-truck loading controls was per-
formed to obtain some actual, measured results of
control efficiencies. (EPA Reports PB-243-3&3,
PB-275-060, EMB-77-GAS-19, EMB-76-16, and EMB 77-18.)
The results of this survey are shown in TABLE 4.5.4,
and they indicate that for carbon adsorption, the
-47-
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TABLE 4.5.1
GASOLINE BARGE VAPOR COMPOSITION
COMPONENT VOLUME CONCENTRATION (%)
C-L + C2 .38
C3 2.60
C4 8-65
C and Heavier 6.37
Air 82
Total HC 18
-48-
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7.
. 50.
168
123.
99.
7 ppm
4 ppm
ppm
9 ppm
96%
26.
182
605.
445.
99.
6 ppm
ppm
5 ppm
9 ppm
87%
.01%
.05%
.17%
.12%
99.65%
TABLE 4.5.2
BARGE VAPOR COMPOSITIONS AFTER SAFETY MODULE
Safety Technique: Dilution with air to maintain 25% L.E.L.(= .35%
total HC by volume) @ 50% initial concentration
Design Flow Rate = 353,000 GPM (47,000 ACFM)
Vapor Analyses for Design
Initial Total HC 5% 18% 50%
Components by Vol.
Cl + C2
C3
C4
C5 + Heavier
Air
Additional Volumes of
Air Added 141.86 141.86 141.86
Safety Technique: Fuel Gas is used to blanket the system and
maintain 50% fuel gas in the vapors
Design Flow Rate = 9900 GPM (1325 ACFM)
Initial Total HC 5% 18% 50%
Components (% by Vol.)
C-L + C2 .06 .19 .53
C3 .36 1.30 3.61
C4 1.20 4.33 12.10
C5 and Heavier .89 3.19 8.90
Fuel Gas* 50 50 50
02 9.98 8.6 5.25
Additional Volumes of
F.G. Added 1.0 1.0 1.0
*Fuel Gas can be assumed to be 100% CH,
4
-49-
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.66
4.32
14.4
10.62
30
.66
4.32
14.4
10.62
30
1.06
7.22
24.03
17.70
.. 50*
TABLE 4.5.2 (CONT.)
BARGE VAPOR COMPOSITIONS AFTER SAFETY MODULE
Safety Technique: Saturate vapors to 30% HC
Design Flow Rate = 5900 GPM (800 ACFM)
Vapor Analysis for Design
Initial Total HC 5% 18% 50%
Components (%)
c1+c2
C3
C4
C- and Heavier
Final Total HC
Volume Increase due to
Gasoline Saturation 36% 17%
* Fully Saturated
Safety Technique: Inert Gas Blanket
Design Flow Rate = 4950 GPM (660 ACFM)
Vapor Analysis for Design
Components (%)
Cl + C2
C3
C4
Cp and Heavier
Inerts
'5%
.11
.72
2.40
1.77
95
0
18%
.38
2.60
.8.65
6.37
82
0
50%
1.06
7.22
24.03
17.70
50
0
-50-
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TABLE 4.5.3
Manufacturers Predicted Vapor Control Unit Efficiencies
Control Technology
Carbon Adsorption
Refrigeration
Thermal Incineration
Removal Efficiency
98.3%
99 %
91.4%
93.9%
99.9%
Comments
For use with N_ or
Inert Gas Generator
For use with
Saturator
For use with N_ or
Inert Gas Generator
For use with
Saturator
For use 'with all
Safety Modules
-51-
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TABLE 4.5.4
CONTROL EFFICIENCIES REPORTED IN EPA LITERATURE
Range of Test Period EPA Report
Control Technology Efficiency Length Reference No.
Carbon Adsorption 91.0-99.5/6 3 days EMB-77-GAS-19
Refrigeration 80.4-93.1$ 3-4 days PB-275-060
EMB-76-GAS-16
EMB-77-GAS-18
Thermal Incineration 99.8$ 1 year PB-243-363
-52-
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control unit had a three day average recovery effi-
ciency of 95.9$, with a range (for a single day) of 91
to 99.5/6. A recovery efficiency of 91$ occurred when
the carbon adsorption system failed to cycle properly
between the twin beds, and the system operated pri-
marily on one bed. Outlet HC concentrations from the
control unit for individual runs ranged from 0% to
12.77$ by volume expressed as propane. The daily
averages ranged from 3-5$ to 0.2$.
Although interpreting these reported test results
provides useful data, there is no direct applicability
to the present barge loading case because differences
in vapor flow rates and HC concentra'tions between truck
and barge loadings prevent comparison of numbers. The
data, however, could be typical of variations that
occur with actual operations. The important difference
is in HC concentrations; .the average concentration for
truck vapors entering the recovery unit ranges from 30
to 55$ for trucks with vapor balance, while barge
vapors for the conditions of this study vary from 5$ to
over 50$, with an average value of 18$. In general,
for a given carbon adsorption unit, when inlet concen-
trations are reduced, the recovery efficiency is also
reduced. This occurs because the exit concentration is
relatively fixed as long as breakthrough or overloading
the carbon bed has not occurred.
The reported test results for three refrigeration
systems gave recovery efficiencies of 80.4$, 93.1$, and
84.4$. (Detailed descriptions were obtained for only
one of the units.) The unit that achieved 84.4$
recovery was reported to have experienced refrigerant
-53-
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leakage which resulted in the condenser operating at a
higher-than-design temperature. Efficiencies for
individual runs ranged from 49 to 91$ on one day and 71
to 95% on the other day. The reported inlet HC
concentrations in the vapor were in the range of 10.8
to 30.5$ with an average of 15.4$. These HC
concentrations compare favorably with expected barge
vapor HC concentrations. Exit vapor concentrations of
1.7 to 4.8$ (as propane) were observed in the tests;
the average was 3.2$.
A reduction in control efficiency occurs in
refrigeration systems as the inlet HC concentration is
reduced. This occurs because outlet concentration is
set by the temperature and pressure of operation, and
it does not vary with inlet concentration.
Reported test results for thermal incineration systems
have shown that very high control efficiencies are
obtainable. Reductions of 99.8$ occurred in normal
operation at a truck loading terminal, and HC
concentrations between 1 and 45 ppm (expressed as
methane) were reported at the outlet of the
incinerators.
The claimed efficiencies of the control technologies
correspond to the efficiencies demonstrated in testing
under normal circumstances (i.e., in the absence of
malfunctioning equipment). A greater effort is made
under test circumstances to ensure proper operation of
the equipment than under normal day-to-day operation.
Therefore it is reasonable to expect that the
efficiency of the control units in normal use will not
be the same as obsefved in test situations, or as given
by the manufacturers. -
-54-
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However, due to the limited data base, it is impossible
to predict reasonably the normal operating efficien-
cies. It can be said, however, that the results are
likely to be lower than results achieved in testing.
The data that have been obtained demonstrate that
thermal incineration, at 99.856, has the highest control
efficiency of the technologies evaluated. The second
most efficient technology is carbon adsorption at 98.3/6
and 99% reduction, depending on the safety system used.
Emission rates for each of the control cases have been
calculated using the control unit reduction efficien-
cies from TABLE 4.5.3 and an estimated collection sys-
tem efficiency of 9856. These rates are given in TABLE
4.5.5. The collection efficiency is theoretically
10056. Most of the vapor collection systems in service
for truck loading depend on vapor displac-eraent by
differential pressure to transport vapors to treatment.
They have experienced collection efficiencies from 3056
to greater than 90/6. The single most prevalent
reasons for the leakage have been poor sealing at the
truck to vapor return line connection and malfunction
of pressure relief valves. It is reasonable to expect
a higher efficiency in the barge vapor collection
system because bolted-flange piping connections are
used.
4.5.2 Secondary Emissions
The secondary emissions produced by the adoption of any
of the control or safety technologies are minor, and
they will be discussed by type and source rather than a
quantitatively.
-55-
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TABLE 4.5.5
PREDICTED ANNUAL HC EMISSION RATES FOR CONTROL CASES
LB/YR HC EMITTED
(Percent reduction from Uncontrolled Base Case)
Safety Modules
Fuel Gas N? Inert Gas
Dilution Saturation Blanket Blanket Generator
Control
Modules
Carbon
Adsorption
Refrigeration
Thermal
N/A
n N/A
21,150
(97.9)
50,061
. (95)
13^,028
(86.7)
35,246
(96.5)
N/A
N/A
49,887
(95)
36,954
(96.3)
105,111
(98.6)
21,150
(97.9)
36,954
(96.3)
105,111
(89.6)
21,150
- (97.9)
N/A - Not Applicable
-56-
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Gaseous secondary emissions are produced by the com-
bustion processes of the inert gas generator and the
thermal incinerator. The combustion gases evolved will
contain C02, CO, unburned HC, NOX, and SOX (if the fuel
contains sulfur). The inert gas product from the inert
gas generator is a water-cooled and scrubbed combustion
gas; therefore, a portion of the contaminants are re-
moved. Tests on other thermal incinerators in gaso-
line-tank-truck loading service have reported measured
concentrations of CO as high as 35 ppm and NOxas high
as 10 ppm. Refrigeration and carbon adsorption control
modules are not producers of gaseous secondary
emissions.
Liquid secondary emissions from the safety and control
modules include a number of contaminated water streams.
The inert gas generator produces a cooling water stream
which is used for contact cooling of the combustion
gases. The absorbed C02 , NOxand SOX (if present)
cause the cooling water to become acidic and corrosive,
and they must be sent to waste water disposal. The
refrigeration system condenses water vapor and gasoline
vapors together and separates them by decanting. The
water is contaminated by hydrocarbons and must be
properly disposed. A final source of secondary liquid
wastes is the overflow stream from the water seals used
to isol.ate portions of the vapor collection system.
This overflow is contaminated by the hydrocarbon
vapors.
-57-
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Solid emissions are not a problem with the safety
modules or with the refrigeration technology. Also
particulate emissions from the thermal incinerators are
predicted to be minor. The carbon adsorption produces
small carbon fines as the carbon particles abrade. The
most significant solids disposal problem occurs when
the carbon in the beds must be replaced, but the
replacement interval is on the order of 10 or more
years and then the problem can be resolved by returning
the carbon t.o the manufacturer for disposal or
regeneration.
4.6 ECONOMICS
Capital (total erected) and annualized (operating and
depreciation) costs were calculated for each of the
control cases studied. All costs are given in terms of
U.S. dollars (second quarter 1978). The basis and
discussions of the capital and annualized costs are
presented in the following paragraphs.
The costs of the modules were calculated separately and
then assembled into specific control cases. By adding
together the capital and annualized costs of the safety
module and control module, the capital or annualized
cost for the specific control case was obtained. The
cost of .using a particular control module will vary
with the type of safety module used, and is dependent
on the degree of compatibility between the safety
module and the control module. Therefore, the cost
effect of the safety module on the control module is
apparent by direct comparison.
-58-
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4.6.1 Capital Costs
The capital cost estimate for any particular safety or
control module represents the total cash outlay
required for the design, procurement, and installation
of the equipment and material within the module. The
costs for major equipment items were obtained from
vendors as engineering estimates or budget prices. The
major equipment items include the specialty vapor
control units, the inert gas generator, and the
blowers. Bulk commodity items such as piping, steel-
work, foundations, electrical supply, and paint were
estimated and priced by Pullman Kellogg's cost
estimating department. An allocation for minor spare
parts was made as a percentage of the total material
cost; however, no spare or backup control units were
included. It was assumed that no additions in utility
plant capacities for cooling water, steam, electricity,
sewers, or fuel gas were required (utility cost rates
include depreciation). Only the costs for short (200
feet) local utility distribution connections were in-
cluded. Sales and use taxes were estimated as a per-
centage of the total material cost. Home office costs,
insurance, commissioning, contingency, and contractor
overhead and profit were estimated as percentages of
the material and labor costs.'
The safety module includes all items from the loading
dock to the control module connection. The total
capital costs for each of the safety modules are shown
in TABLE 4.6.1. The itemized cost listings for the
safety modules are in Appendix B. The costs for
fuel-gas and nitrogen-blanketing modules are grouped at
$200,000, a n d _ t h e~ remaining modules are
-59-
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TABLE 4.6.1
CAPITAL COST OF SAFETY. MODULES
MODULE COST
Dilution $330,800
Saturation 307,200
Fuel Gas Blanketing 209,100
N Blanketing 198,300
Inert Gas Generator 364,100
-60-
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grouped between $300,000 and $365,000. It should be
noted that the safety module utilizing N? for blanket-
ing does not include the capital cost for the liquid N2
storage tank and vaporizer. This equipment is leased
and thus becomes an operating expense rather than a
capital expenditure. If these items were purchased
rather than leased, N2 blanketing would not be the
least expensive module, and it would most likely cost
about $320,000.
The control module cost includes the vapor control unit
and the associated utility connections. Total capital
costs for each of the control modules are shown in
TABLE 4.6.2. ' , .
The costs for thermal incineration as a group are much
less expensive than the competing technologies. The
capital cost of thermal -incineration control schemes
range from $148,800 to $297,600, depending on the
safety module applied. Control module costs for use
with saturation and N2 or inert gas generator modules
are lowest since flow rates are not increased substan-
tially, as compared to dilution or fuel gas blanketing
which raise flow rates substantially. Capital cost for
a thermal incineration module to be used with the
dilution safety module was not obtained; however, the
excessive operating cost makes it prohibitive due to
high fuel requirements.
Carbon adsorption is the highest capital cost techno-
logy. Carbon adsorption with saturation costs $661,800
and carbon adsorption with inertion cost $458,300. The
difference in cost is caused because larger carbon beds
-61- -
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TABLE 4.6.2
CAPITAL COST FOR CONTROL MODULES
Carbon Adsorption
- For Use W/ Saturation $661,800
- For Use W/N2 or Inert Gas Generator $458,300
Refrigeration
- For Use W/Saturation - $614,800
- For Use W/N_ or Inert Gas Generator $614,800
Thermal Incineration
- For Use W/Dilution N/A
- For use W/Saturation $171,100
- For use W/Fuel Gas Blanketing $297,600
- For Use W/N2 $148,800
- For Use W/Inert Gas Generator $148,800
-62-
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are required for saturation than for inertion due to
the gasoline added.
Refrigeration modules are identically priced at
$614,800 for use with saturation or inertion since the
refrigeration duty is based on a saturated gasoline-air
mixture.
The cost of each case studied is shown in TABLE 4.6.3.
As the table indicates, thermal incineration systems
establish the lowest capital expenditure, from a low of
$347,100 to a high of $506,900 and an average cost of
$459,800. The carbon adsorption systems range from
$656,600 to $969,000 with an average figure of
$814,000. The refrigeration systems range from
$813,000 to $972,900 and average $902,600. For any of
the three control technologies, the lowest capital cost
is incurred when nitrogen inert blanketing is
employed.
The capital cost for barge modifications reported by
others ranged from $50,000 to $150,000 (1976 dollars)
per barge. (Refer to EPA-450/3-76-038a, page 159). A
detailed description of the modifications covered by
these reported costs could not be determined however.
The total erected costs for modifying the barges to
conform .with the modifications shown in Figures 4.3.2
and 4.3.3 (with the exception of the direct sighting
port) are estimated to be $152,000 per barge. These
costs do not include the costs "due to cleaning,
degassing, or lost revenue during the period the barge
is removed from service. These costs are all incurred
by the barge owner.
-63-
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TABLE 14.6.3
CAPITAL COSTS OF BARGE LOADING EMISSION CONTROL SYSTEMS ($)
Emission
Control Module Type
Carbon Adsorption
Refrigeration
Thermal Incineration
Safety Module Type
Dilution
N/A
N/A
-
Saturation
969,000
922,000
478,300
Fuel Gas
Blanketing
N/A
N/A
506,700
N
Blanketing
656,600
'813,100
347,100
Inert Gas
Generator
816,400
972,900
506,900
-------
M.6.2 Annualized Costs
Components included in annualized costs are utilities,
maintenance, labor, capital recovery charges, and
gasoline recovery credits (if any). Utility costs
include electricity, fuel gas, N2 gas, steam, cooling
water, and gasoline.
The costs for the utilities are:
Electricity $.OU/KWH
Natural Gas $2.73/1000 ft3
N2 Gas $2.90/1000 ft3
(delivered as liquid)
N2 Storage and
Vaporizer $1350'/month
Steam $3-50/1000 Ib
Cooling Water $.15/1000 gal
Gasoline $.40/gal
The unit costs for these utilities are representative
of prices obtainable on the Texas Gulf Coast.
Maintenance costs for equipment have been estimated as
a percentage of the capital cost.
The percentages used for maintenance costs of the
safety modules are:
Dilution 2%
Fuel Gas' Blanketing 1%
Inert' Gas Generator 3%
N2 Blanketing 1%
Saturation 5$
The percentages used for maintenance costs of the
control modules are:
-65-
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Carbon Adsorption 3%
Refrigeration 2%
Thermal Incineration 1%
Additional labor (over the uncontrolled case) has been
assumed to be one extra operator during the loading
periods for both safety control modules. The labor
rates are approximately union scale for the area and
include fr i.n ge benefits. A labor rate of
$12/operator-hour is used. Capital charges are based
on a 10/6 annual interest rate and 15 year equipment
life with a capital recovery factor of 0.13147.
Administrative expenses are calculated as ,4$ of the
capital cost. A credit for gasoline recovery is taken
at $.40/gal for those cases where a reduction in
gasoline losses is achieved.
TABLE 4.6.4 contains the annualized costs for each of
the safety modules. The annualized cost for the inert
gas generator is lowest at $95,600, with dilution only
slightly higher at $99,200. The remaining safety
modules rank upward from fuel gas blanketing to
gasoline saturation, to N 2 blanketing. These three
modules range from $142,500 to $162,200.
Annualized costs for the control modules are listed in
TABLE 4.6.5. The cost for each control module depends
on the safety module used with it. For the control
modules that recover gasoline (carbon adsorption and
refrigeration), the annualized costs are reduced
dramatically when the saturation safety module is used.
This is due to the credit for the increased gasoline
-66-
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TABLE 4.6.4
ANNUALIZED COSTS FOR SAFETY MODULES ($)
Inert Gas
Dilution Saturate Fuel Gas N- Generator
Gasoline - 76,800
Electricity 11,936 328 597 298 578
Fuel Gas - - 91,973 - 8354
N2 - 113,903
Steam - 2919
Cooling Water - - - - 2520
Total
Utilities 11,936 80,047 92,570 11-4,199 11,452
Capital and Ad-
ministrative
Costs 56,670 52,675 38,854 34,002 61,403
Maintenance 6,610 15,360 2,.091 1,983 IX),743
Labor 24,000 12,000 12,000 12,000 12,000
Total
Annualized
Cost 99,216 160,082 142,515 162,184 95,598
-67-
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TABLE 4.6.5
ANNUALIZED COSTS FOR CONTROL MODULES
($)
Control Module
Safety Module
Carbon Adsorption
Saturation N_ or
Inert Gas
Generator
Refrigeration
Saturation
N2 or
Inert Gas
Generator
Utilities 3,640
Capital and
Administrative
Costs 113,479
Maintenance and
Labor 19,854
(Gasoline Credit) (130,447)
Total Costs
6,526
2,432
78,584
13,749
(76,186)
18,579
5,960
105,420
,12,296
(121,252)
2,424
5,960
105,420
12,296
(70,814)
52,862
Control Module
Safety Module
Utilities
Capital and
Administrative
Costs
Maintenance and
Labor N/A
(Gasoline Credit) (0)'
Total Costs N/A
Thermal Incineration
Dilution
453,464
N/A
Saturation
473
29,342
1,711
(0)
Fuel Gas
Blanketing
946
51,030
2,976
(0)
N_ or Inert
Generator
473
25,515
1,488
(0)
31,526
54,952
27,476
N/A = Not Applicable
-68-
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recovered. Thus the reduction in control module
annualized cost when using saturation rather than
blanketing with carbon adsorption is 65%, and with
refrigeration it is 95.4$. Ranking the average
annualized costs for each control technology starting
with the lowest indicates carbon adsorption is least
costly, followed by refrigeration, and finally by
thermal incineration. The annualized cost calculation
for thermal incineration used with dilution was
abandoned due to a utility cost of $453,000, which
makes it non-competitive. The utility cost is for the
fuel gas that must be used to burn the dilute gasoline
vapor mixture.
The annualized costs for the complete systems which
include the safety and control modules are shown in
TABLE 4.6.6. The costs range from $115,000 to
$215,000. The lowest cost for each control technology
is achieved when an inert gas generator is used as the
safety module. As a group, the carbon adsorption
systems have the lowest average annualized cost at
$153,800. The average costs for refrigeration and
thermal incineration systems are virtually identical at
$175,300 and $175,500 respectively. In each case
(except for the dilution-thermal incineration)
annualized cost was greater due to the safety module
than due-to the control module.
If the barges are owned by the terminal operator, the
capital charges are amortized along with the dockside
equipment. However, if the barges are leased from an
independent barge operator (which appears to be the
more common procedure) tjb_e costs are reflected in the
-69-
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TABLE 4.6.6
ANNUALIZED COSTS FOR ONE GASOLINE BARGE LOADING EMISSION CONTROL SYSTEM
Emission Control
Module Type
Carbon Adsorption
Refrigeration
Thermal Incinera-
tion
Total Annualized Cost for Each Combination
of Safety and Control Modules ($1,000)
Dilution
I
N/A
N/A
>550
Saturation
165
160
190
Fuel Gas
Blanketing
N/A
N/A
195
Nitrogen
Blanketing
180
215
190
Inert Gas
Generator
115
150
125
o
I
-------
lease price, since the barge operator must recover the
cost of modification. How these costs are reflected in
leasing prices depends on the terms negotiated between
the barge operator and the oil company.
From 64.4$ to 98.5$ of the total annualized cost is a
function of safety which has the effect of obscuring
the relative costs of the control modules themselves.
4.6.3 Economic Analysis
This analysis will center on the determination of cost
effectiveness for each of the control cases. Cost
effectiveness must relate some parameter of cost to
some parameter of performance. The annualized cost
will be used as the cost parameter. The performance
parameter will be the net reduction in HC emissions
over the uncontrolled or base case. It is assumed that
the annualized cost of the uncontrolled case is zero.
The cost effectiveness will be measured in terms of
pounds of HC controlled annually per dollars spent
annually. Thus the cost effectiveness index is
expressed as # HC/ $ and the higher the index, the
greater the cost effectiveness. The cost effectiveness
of each control case is shown in TABLE 4.6.7. The cost
effectiveness ranges from 4.2 # HC/$ to 8.50 0 HC/$.
The most cost effective system is carbon adsorption
with ine^t gas generation at 8.50 # HC/$. The next two
cases are thermal incineration and refrigeration, both
using inert gas generation, at 8.01 # HC/$ and 6.08 #
HC/$ respectively.
As an alternate approach to evaluation of the control
..„ systems, consider the additional cost of the product
-71-
-------
TABLE 4.6.7
COST EFFECTIVENESS FOR CONTROL CASES
LB. HC CONTROLLED/$ OF ANNUALIZED COST ($/LB)
Safety Module Type
Fuel Gas Inert Gas
Dilution Saturation Blanketing N Generator
Emissions
Control Module
Type #HC($/LB) #HC($/LB) #HC($/LB)
Carbon N/A 5.75(0.17) N/A 5.37(0.19) 8.50(0.12)
Adsorption
Refrigeration N/A 5.37(0.19) N/A 4.20(0.24) 6.08(0.16)
Thermal N/A 5.08(0.20) 4.85 5.20(0.19) 8.01(0.12)
Incineration
N/A - Not Applicable
-72-
-------
shipped by barge when using a vapor control system.
For the proposed 6 x 10 ° bbl annual gasoline through-
put, the effect of the least cost effective control
scheme (refrigeration with N2 blanketing at 4.2 # HC/$)
on the cost of gasoline is approximately one dollar per
1230 gallons or 0.08
-------
cases. The annual throughputs used varied from three
to 24 million barrels per year. The projected results
are shown in TABLE 4.6.8. Figures 4.6.1, 4.6.2, 4.6,3,
and 4.6.4 are curves of cost effectiveness versus
annual throughput for the various control cases. The
information in TABLE 4.6.8 is plotted in -these figures.
When the cost effectiveness index for recovery schemes
reaches 12.8 # HC/$, a break even point is reached,
i.e. the value of the gasoline recovered is equal to
the annualized-cost required to recover it. Above this
point the vapor recovery system begins to pay back
direct operating costs and capital charges. If only
direct operating expenses are considered and capital
charges neglected, the break even point'would be
lower.
-74-
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TABLE 4.6.8
SUMMARY OF RESULTS OF COST EFFECTIVENESS CURVES (HC/$)
Throughput
(10b BBL/YR)
Carbon Adsorption'
w/Saturation
w/N2
w/Inert Gas Gen.
Refrigeration
^/Saturation
w/N2
w/Inert Gas Gen.
1
Thermal Incin.
w/Saturation
w/Fuel Gas Blanket
w/N2
w/Inert Gas Gen.
12
18
24
2.89
3.31
3.82
5.75
5.37
8.50
8.61
6.78
14.38
11.47
7.80
21.98
17.16
9.19
46.56
22.81
10.08
105.70
2.73
2.55
2.86
5.37
4.20
6.08
7.96
5.36
9.72
10.47
6.21
13.88
15.30
7.40
24.24
19.89
8.17
38.68
3.56
3.37
3.96
4.70
5.08
4.85
5.20
8.01
5.92
5.69
5.81
10.48
6.46
6.22
6.17
12.40
7.10
6.87
6.58
15.15
7.47
7.24
6.80
17.04
-------
u
ac
=»=
O
U
70
60
50
40
H 30
en
en
0)
c
Q)
•rH
-P
g 20
U-l
w
10
CARBON ADSORPTION with
A - Saturation Module
B - N_ Blanketing
C - Inert Gas Generator
12
15
18
21
24
Annual Throughput 10 BBL/YR
Figure 4.6.1 Cost Effectiveness Projections Carbon Adsorption
-76-
-------
70
60
50
X
w
Q
M
en
1 4°
w
>
M
EH
U
W
h 30
O
U
20
10
REFRIGERATION W/
A - SATURATION
B - N2 BLANKETING
C - INERT GAS GENERATOR
12
15
18
21
24
ANNUAL THROUGHPUT 10 BB&/YR
Figure 4.6.2
Cost Effectiveness Projections
Refrigeration
-77-
-------
70
60
u 50
X
=«=
X
w
Q
2
cn 40
w
w
S
W
EH
U
W
O
U
30
20
10
THERMAL INCINERATION WITH
A - SATURATION
B - FUEL GAS BLANKETING
C - N2 BLANKETING
D - INERT GAS GENERATOR
VIRTUALLY
INDISTINGUISHABLE
15
18
ANNUAL THROUGHPUT 106 BBL/YR
21
24
Figure 4.6.3 - Cost Effectiveness Projections
Thermal Incineration
'. -78-
-------
u
ffi
\
=*:
X
w
Q
2
M
CO
W
U
W
Cfl
o
u
70
A - CARBON ADSORPTION W/INERT GAS GENERATOR
B - REFRIGERATION W/INERT GAS GENERATOR
C - THERMAL INCINERATION W/INERT GAS GENERATOR,
60 -
50
40
30
20
10
12
15
18
21
24
ANNUAL THROUGHPUT 10 BBL/yr*
Figure 4.6.4 Cost Effectiveness Projections
Comparison
-79-
-------
REFERENCES
BOOKS
1. Hughes, John R., "Storage and Handling of Petroleum Liquids:
Practice and Law," Charles Griffin and Company Limited,
London, Great Britian, W.C.-2, 196?
2. Oil Companies International Marine Forum,- "International Oil
Tanker and Terminal Safety Guide," Second Edition, Halsted
Press, John Wiley and Sons Inc., New York, 1974
3. Wooler, R. G., "Tankerman1s Handbook," Second Edition,
Edward W. Sweetman, Publisher, New York 1950
REPORTS
1. "API Bulletin 2514: Evaporation Loss from Tank Cars, Tank
Trucks, and Marine Vessels," American Petroleum Institute,
Washington, D.C., 20037, 1959
2. "API Bulletin 25-14-A: Hydrocarbon Emissions from Marine
Vessels Loading of Gasolines," American Petroleum Institute,
Washington, D.C., 20037, 1976
-80-
-------
3. Amoco Oil Company; "Demonstration of Reduced Hydrocarbon
Emissions from Gasoline Loading Terminals," EPA Report No.
EPA-650/2-75-OH2, EPA, Research Triangle Park, N.C. 27711,
1975 '
M. Betz Environmental Engineers, Inc., "Gasoline Vapor Recovery
Efficiency Testing at Bulk Transfer Terminals Performed at
Pasco-Denver Products Terminal," EPA Report No. 76-GAS-17,
EPA, Research Triangle Park, N.C. 27711, 1975
5. Betz Environmental Engineers, Inc., "Air Pollution Emission
Test - Diamond Shamrock Gasoline Terminal; Edwards Vapor
Control System; Denver, Colorado," EPA Report No. 76-GAS-16,
EPA, Research Triangle Park, N.C. 27711
6. Betz Environmental Engineers, Inc., "Texaco Westville Sales
Terminal; Westville, New Jersey," EPA Report No. 77-GAS-18,
EPA, Research Triangle Park, N-.C. 27711
7. Environmental Protection Agency, "Control of Hydrocarbons
from Tank Truck Gasoline Loading Terminals," EPA Report No.
EPA-450/2-77-026, EPA, Research Triangle Park, N.C. 27711
8. EPA, "Compilation of Air Pollutant Emission Factors, (1977
Supplement 7)," EPA, Research Triangle Park, N.C. 27711
9. Pullman Kellogg, a Division of Pullman Inc., "Evaluation of
Control Technology for Benzene Transfer Operations,"
prepared under EPA Contract No. 68-02-2619, Work Assignment
No. 2; EPA, Research Triangle Park, N.C. 27711
10. Radian Corp., "A Study of Vapor Control Methods for Gasoline
Marketing Operations Volume II - Appendix," EPA Report No.
EPA-M50/3-75-OU6-b, EPA, -Research Triangle Park, N.C. 27711
-81-
-------
11. Radian Corp., "Background Information on Hydrocarbon Emis-
sions from Marine Loading Terminal Operations, Volumes I &
II," EPA Report No. EPA-450/3-76-038 a,b; EPA, Research
Triangle Park, N.C. 27711
12. Scott Environmental Technology, Inc., "Control Characteris-
tics of Carbon Beds for Gasoline Vapor Emissions," EPA
Report No. EPA-600/2-77-057, EPA Research Triangle Park,
N.C. 27711
13. Scott Environmental Technology, Inc., "Air Pollution Emis-
sion Test - Phillips Fuel Company; Hackensack, New Jersey,"
EPA Report No. 77-GAS-19; EPA, Research Triangle Park, N.C.
27711
Trade Journals
1. Southerland, M.E., and H.W. Wegert. "Flash Arresters
Successfully Forestall An Acetylene Catastrophe". The Oil
and Gas Journal, March 13, 1972, pp. 73-75.
-82-
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APPENDIX A
LEGEND
EQUIPMENT AND PIPING SYMBOLS
• INSTRUMENT CONTROL
"* LINE
-$ PROCESS FLOW LINE
5—da—J
CONTROL VALVE
5 tX $ BLOCK VALVE
MOTOR OPERATED
VALVE
5—f\j $ CHECK VALVE
-5 FLAME ARRESTOR
1 5 ORIFICE PLATE
FLEXIBLE HOSE
SJ 5 LIQUID SEAL POT
/• -\ "
CENTRIFUGAL PUMP
BLOWER
PRESSURE^VACUUM
VENT VALVE
Instrument Abbreviations
FIC - Flow Indicating Controller
FS - Flow Switch
I - Interlock "
LI - Level Indicator
LS - Level Switch
PI - Pressure Indicator
PIC - Pressure Indicating Controller
TIC - Temperature Indicating Controller
XA - Warning Alarm (Audible)
XL - Warning Light
-83-
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APPENDIX B
CAPITAL COST DATA
FOR SAFETY AND CONTROL MODULES
-84-
-------
CAPITAL COST DATA
MODULE - DILUTION
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion
Contractors OH & .P
Contingency
Total Erected Costs
COST(MATERIAL AND LABOR)
(.$ xlOOO)
71.0
8.0
4.0
99.1
8.0
10.6
3.0
1.1
20.9
20.9
4.3
3.1
1.1
2.6
52.2
20.9
330,8
-85-
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CAPITAL COST DATA
MODULE - SATURATION
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion
Contractors OH &. P
Contingency
COST(MATERIAL AND LABOR)
($ xlOOO)
5.2
12.4
26.7
4.0
22.5
10.0
54.6
7.0
45.5
3.0
2.0
19.2
19.2
3.5
2.9
0.9
2.4
48.0
19.2
Total Erected Costs
307.2
-86-
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CAPITAL COST DATA
MODULE - FUEL GAS BLANKETING
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion
Contractors OH & P
Contingency
COST(MATERIAL AND LABOR)
(.$ xlOOO)
19.7
U.O
1.6
6.0
48.7
4.0
41.4
3.0
1.0
13.1
13.1
2.2
2.0
0.5
' 1.6
32.7
13.1
Total Erected Costs
209.1
-87-
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CAPITAL COST DATA
MODULE - N BLANKETING
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion
Contractors OH &,P
Contingency
Total Erected Costs
COST(MATERIAL AND LABOR)
(.$ xlOOO)
19.7
4.0
4.0
6.0
51.4
4.0
30.8
3.0
1.0
12.4
12.4
2.3
1.8
0.6
1.5
31 .0
12.4
198.3
-88-
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CAPITAL COST DATA
MODULE - INERT GAS GENERATOR
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion
Contractors OH & P
Contingency
Total Erected Costs
COST(MATERIAL AND LABOR)
(.$ xl.000)
19.7
91.7
4.0
8.0
6.0
57.4
U.O
30.8
3.0
1.5
22.6
22.6
6.0
3.4
1.5
2.8
56.5
22.6
364.1
-89-
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CAPITAL COST DATA
MODULE - CARBON ADSORPTION W/INERTION
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion
Contractors OH &._P
Contingency
COST(MATERIAL AND LABOR)
($ xlOOO)
231.3
12.0
4.0
30 .0
3 .0
2.5
28.3
28.3
9.8
4.2
2.4
3.5
70.7
28.3
Total Erected Costs
458.3
-90-
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CAPITAL COST DATA
MODULE - CARBON ADSORPTION W/SATURATION
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion
Contractors OH &_P
Contingency
Total Erected Costs
COST(MATERIAL AND LABOR)
(.$ oclOOO)
338.4
12.0
4 .0
11.5
36-0
3.0
3.5
40.8
40.8
14.2
6.1
3.5
5.1
102.1
40.8
661.8
-91-
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CAPITAL COST DATA
MODULE - REFRIGERATION W/INERTION OR SATURATION
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion
Contractors OH & P
Contingency
COST(MATERIAL AND LABOR)
(.$ xlOOO)
303.0
12.0
4.0
12.3
42.0
3.0
3.2
38.0
38.0
12.8
5.7
3.2
4.7
94.9
38.0
Total Erected Costs
614.8
-92-
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CAPITAL COST DATA
MODULE - THERMAL INCINERATION W/SATURATION
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion
Contractors OH &.P
Contingency
COST(MATERIAL AND LABOR)
(.$ xlOOO)
75.4
9.2
2.3
7.1
6.9
3.5
1.1
10.6
10.7
3.5
1.3
1.1
1.2
26.6
10.6
Total Erected Costs
171.1
-93-
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CAPITAL COST DATA
MODULE - THERMAL INCINERATION W/FUEL GAS BLANKETING
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion .
Contractors OH &- P
Contingency
COST(MATERIAL AND LABOR)
.-(.$ xlOOO)
131.2
16.0
4.0
12.4
12.0
6.0
2.0
2.0
18.4
18.4
5.8
2.8
2.0
2.2
46.0
18.4
Total Erected Costs
297.6
-94-
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CAPITAL COST DATA
MODULE - THERMAL INCINERATION W/INERTION
DESCRIPTION
Exchangers
Towers
Pumps & Compressors
Special Equipment
Fire & Safety Equipment
Concrete Work
Steel Work
Piping
Electrical
Instruments
Insulation & Paint
Freight (Unallocated)
Field Construction Costs
Home Office Costs
Sales & Use Taxes
Insurance
Spare Parts
Project Completion
Contractors OH fr-P
Contingency
COST(MATERIAL AND LABOR)
(.$ xlOOO)
65.5
8.0
2.0
6.2
6.0
3.0
1.0
9.2
9.2
2.9
1.4
1.0
1.1
23.0
9.2
Total Erected Costs
148.8
-95- '
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APPENDIX C
Item
Air Products & Chemicals, Inc.
260 North Belt East, Suite 200
Houston, Texas 77060
Buffalo Forge Co.
Fred P. Heinzmann Co., Inc.
1425 Blalock Rd., Suite 220
Houston, Texas 77055
Edwards Engineering Corp.
Hendricksen Co., Inc.
p. 0. Box 55565
Houston, Texas 77055
Hydrotech Engineering, Inc.
p. 0. Box 45042
Tulsa, Oklahoma 74145
Liquid Air Inc. -
p. 0. Box 15313
Houston, Texas 77020
National Air Oil Burner Co., Inc.
3717 Montrose Blvd., Suite 431
Houston, Texas 77006
Nitrogen Blanketing
Systems
Blowers
Refrigeration
Vapor Recovery Units
Carbon Adsorption
Vapor Recovery Units
Nitrogen Blanketing
Systems
Thermal Incineration
-96-
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TECHNICAL REPORT DATA
(Please read Inunctions on the reverse before completing)
1. REPORT NO.
EPA-600/2-79-069
3. RECIPIENT'S ACCESSION/ NO.
4. TITLE AND SUBTITLE
Control Technology Evaluation for Gasoline Loading
of Barges
5. REPORT DATE
March 1979
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
D. Gee and W. M. Talbert
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Pullman Kellogg
16200 Park Row, Industrial Park Ten
Houston, Texas 77084
10. PROGRAM ELEMENT NO.
1AB604B
11. CONTRACT/GRANT NO.
68-02-2619, Task 9
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final: Thru 11/78
14. SPONSORING AGENCY CODE
EPA/600/13
is. SUPPLEMENTARY NOTES
project officer is Irvui A. Jef coat , MD-62, 919/541-
2547. For details contact B.A. Tichenor at same phone; Jefcoat is no longer with
16. ABSTRACT
The report gives results of a study to determine the feasibility, safety,
and cost of methods to control the emission- of hydrocarbon vapor during the loading
of gasoline barges. Approximately 4 Ib of hydrocarbons are emitted per 1000 gal. of
gasoline loaded; annually about 1 million Ib of hydrocarbons may be emitted at a ter-
minal pumping 6 million barrels of gasoline. Vapor control techniques evaluated
included carbon adsorption, refrigeration, and thermal incineration. Hydraulic flash
arresters prevent flame transmission between the barge and vapor control system.
Safety methods are also required to render the barge vapors non-flammable prior
to collection and transport. Safety methods evaluated were dilution, saturation, and
blanketing with fuel gas, liquid nitrogen, and inert gas. All combinations of vapor
control/safety systems were evaluated. In terms of cost, dilution was determined
non-applicable for all three vapor control methods; fuel gas blanketing was appli-
cable only with thermal incineration. Costs for the applicable combinations range
from #0. 12/Ib of hydrocarbon vapor (for inert gas blanketing combined with carbon
adsorption) to S'O. 24/lb (for liquid nitrogen blanketing/refrigeration). These costs
correspond to gasoline cost increases of 0.048j^ to 0.096^/gal. ,respectively. More
accurate estimates await demonstration of one or more vapor control/safety systems
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATl Field/Group
Pollution
Gasoline
Fueling Systems
Barges
Hydrocarbons
Vapors
Carbon
Refrigeration
Incinerators
Nitrogen
Blanketing -
Pollution Control
Stationary Sources
Carbon Adsorption
13 B
21D
13A
07C
07D
07B
07A,13H
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
103
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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