remocion de mercurio

1. 1
Session No. 43, Paper No. 43c
Removal of Trace Mercury Contaminants from
Gas and Liquid Streams
in the LNG and Gas Processing Industry
by
Julio A. Rios, MEChE
Process Manager, LNG
David A. Coyle, BSChE
Chief Technology Engineer, LNG
Charles A. Durr, MSChE
Technology VP, LNG & Gas Processing
Felix F. De la Vega, P.E., MSChE
Brian M. Frankie, MEChE
The M. W. Kellogg Company
Houston, Texas, USA
Prepared for presentation at the
AIChE 1998 Spring National Meeting
New Orleans, Louisiana, USA
Tuesday, March 9, 1998
Session: Cryogenic Gas Processing II
UNPUBLISHED

2. 2
AIChE shall not be responsible for statements or opinions contained in papers or printed
in its publications
ABSTRACT
Mercury, present as a contaminant innaturalgas and its associated condensates, has to be removed
to prevent corrosion in aluminumequipment as wellas to avoid downstreamcatalyst poisoning. Elemental
mercury present in the gas phase has traditionally been removed by adsorption on sulfur impregnated
carbon or on an alumina carrier. Currently there are other options including the use of special types of
molecular sieves which are regenerated, and by other fixed bed adsorbents.
Similarly, mercury is removed from natural gas condensates used as steam cracking feedstock to
avoid downstream poisoning of selective hydrogenation catalyst. Some environmental concerns on the
disposal of the spent adsorbent containing mercury or of the mercury released from the molecular sieve
regenerating medium are briefly discussed.
Also presented is how mercury in the feed gas to an LNG plant distributes itself to the different
products and internal streams.

3. 3
INTRODUCTION
Althoughrelativelyhighlevels ofelementalmercurywere discovered inthe Groningen(Holland) field
as early as 1969, the first recorded cold box failure attributed to mercury corrosion was in the aluminum
spiral wound heat exchanger of the LNG plant at Skikda, Algeria1,2
in 1974. Since this time, mercury in
natural gas has become a major concernincryogenic gas processingindustries. These industries, including
liquefied natural gas (LNG), liquefied petroleum gases (LPG), and olefins, often use aluminum heat
exchangers in their cold boxes. Mercury corrosion of aluminum exchangers has led to several additional
failures since the problems at Skikda. Inaddition, mercuryaccumulationcanlead to poisoningofcatalysts
used in olefin processes, personnel safety hazards, and waste disposal difficulties. This paper describes
different forms of mercury found in natural gas, the distribution of mercury in process plants, methods of
mercuryattack, the latest options for treatment ofmercurycontaminated process streams, and the treatment
and disposal of mercury contaminated wastes.
SOURCES AND DISTRIBUTION OF MERCURY
Mercury Forms: Mercury is present in natural gas and natural gas associated condensates, as
organometallic and inorganic compounds, and inthe elemental(metallic) formdependingonthe originofthe
gas. The elemental form can be found in either the vapor or liquid phase. The organometallic (typically
dimethylmercury, methylethylmercury, or diethylmercury) and inorganic (suchas HgCl2) compoundsdrop
into the liquid phase in any fractionation of the natural gas streams. Vapor phase elemental mercury is a
primary culprit in corrosion of aluminum exchangers inside cryogenic cold boxes.

4. 4
Elementalmercurythat leaves the plant inthe liquid phase naturalgas condensate streams is a primary
source ofcorrosioninaluminumequipment inolefinplants that crack liquids and LPG (propane and butane)
recovered from the natural gas plants. Mercury also poisons the selective hydrogenationcatalysts inolefin
plants, and can pose inhalation hazards to workers.
Organometallic and inorganic mercury usually end up in the condensate stream fromthe naturalgas
plant. These compounds are important environmentaltoxins that are easilyabsorbed and accumulated by
biological organisms. The presence of these compounds innaturalgas condensate streams leads to waste
disposal problems and safety hazards to workers.
Mercury Sources: Elemental mercury is a natural contaminant present at the wellhead in various
concentrations at different geographic locations. The concentrationofelementalmercuryinthe gas streamis
often expressed in g/Nm3
, which is a very small number. Table 1 is a comparisonbetween g/Nm3
with
more conventional expressions (such as ppm, ppb and ppt). Generallyspeaking, elementalmercurylevels
have been found to be the highest in Southeast Asian gases (up to 400 g/Nm3
in the vapor phase) and
lowest in United States Gulf Coast gases (as low as 0.02 g/Nm3
)3
, although wide variation is known to
occur even within local regions. However, evenat the verylowest naturalconcentrations it is stilldesirable
to reduce the amount ofmercurybefore anycryogenic processing, where mercurycanaccumulate to higher
concentrations.
The mechanismfor formationoforganometallic mercuryis not known. Current postulates suggestthat
elemental mercury may react withthe walls ofreboilers and catalytic furnaces to formactive species which
can then react with methane, ethane, the products of a catalytic cracker, and other organic compounds4
.

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TABLE 114
VAPOR PHASE ELEMENTAL MERCURY IN NATURAL GAS
COMPARISON OF CONCENTRATION EXPRESSIONS
g/Nm3
8,500
850
85
8.5
0.85
0.085
0.0085
MOL%
0.000,1
0.000,01
0.000,001
0.000,000,1
0.000,000,01
0.000,000,001
0.000,000,000,1
PPM
1
0.1
0.01
0.001
0.000,1
0.000,01
0.000,001
PPB
1,000
100
10
1
0.1
0.01
0.001
PPT
1,000,000
100,000
10,000
1,000
100
10
1
Mercury Distribution5
: Vapor phase elementalmercurydistributioninliquefied naturalgas (LNG)
plants has been studied to determine the areas most in danger of mercuryattack, and whichstreams have
the highest concentration. Three primary areas have been identified.
First, when fractionating natural gas (e.g. scrub column followed by deethanizer, depropanizer and
debutanizer), the majority of the mercury ends up in the butane and some in the propane. Most of the
mercury condenses in the scrub column because of its very low vapor pressure, and because this column
operates at low temperatures (below -30 C), and highpressures (above 50 bar). The mainpurpose ofthe
scrub column is to remove the bulk of the heavy components from the natural gas which can freeze inthe
main cryogenic exchanger. Table 2 shows mercury vapor pressure as a function of temperature.
The remainingcolumns inthe fractionationsectionrecover the C4 and lighter components containedin
the scrub column bottom. LNG plant configurations vary, but both the propane and butane streams are
often reinjected back into the naturalgas enteringthe aluminummaincryogenic exchanger. Inthis case, the

6. 6
mercury in these streams can freeze and accumulate in the tubesheets and tubes of the natural gas circuit.
Mercury freezing will occur at temperatures below -39 C, and where the mercuryconcentrationis greater
than the mercury solubility in the liquid stream.
Secondly, in addition to the above reinjectionstreams into the mainexchanger, some ofthe mercury
also escapes in the overhead of the naturalgas scrub column. This streamis sent directlyto the naturalgas
tube circuit in the main exchanger where it freezes and accumulates. Figure 1 shows the mercury
distributionthrougha typicalLNG process withreinjectionofpropane and butane. Figure 1 was developed
at M. W. Kellogg using interactionparameters and k-values for mercuryinhydrocarbons developed from
proprietary data.
The fractions bythe different streams show the amount ofmercurythat streamcontains based onone
unit of mercury in the feed. These fractions were calculated using vapor-liquid equilibria only; in actual
operation, the 0.99 mercuryfractionshownexitinginthe LNG would freeze and accumulate inthe aluminum
tube circuits of the main exchanger.
Finally, a small amount ofthe elementalmercurygoes inthe overhead streams ofthe deethanizer and
depropanizer. These streams provide makeup mixed refrigerant for the process and willallow mercuryto
accumulate in the mixed refrigerant loop. The refrigerant flows up throughone or more separate aluminum
tube circuits in the main exchanger, is expanded, and flows down the shell side of the exchanger. This
mercury is most likely to freeze in the refrigerant tube circuits.
TABLE 2
VAPOR PRESSURE OF ELEMENTAL MERCURY15
TEMPERATURE(deg.C) PRESSURE(mmHg)
-38.9 2.19x10E-6
-20 23.36x10E-6

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0 199.6x10E-6
25 1.93x10E-3
40 6.34x10E-3
100 0.277
Mercury Concentrations: Since awareness ofthe problems withmercurycorrosionhas increased,
many cryogenic gas processing facilities have installed guard beds to scavenge elementalmercuryfromthe
vapor phase. Specifications of the outlet gas from these beds are generally about 10 nanograms per
standard cubic meter (0.01 g/Nm3
) ofgas, and are based more onmercurymeasurement limitations rather
than removal limitations. At a large LNG plant producing 8,000 tonnes of LNG product per day, 0.01
g/Nm3
translates to about 36 grams of mercury per year remaininginthe gas stream, whichcanstilldrop
out and freeze in the maincryogenic exchanger. Based onthe distributionanalysis inFigure 1, almost allof
this mercury will freeze to solid mercury in the main exchanger (pure mercury freezes below - 39C).
Much less work has beendone onthe presence oforganometallic and inorganic (as salts) mercuryin
process plants. One source6
reports typicalcondensate concentrations oforganometallic mercuryinthe10
to 1000 ppb(weight) range. A second source7
reports a typical concentrationof30 to 60 ppb(weight) in
AlgerianHR720 condensate feedstock for ethylene plants. Another naturalgas condensate has beenfound
to contain 5% elemental, 21%inorganic, and 74% organometallic mercury16
.
Mercury Detection: Problems with mercury detection mean that operators will often have no
indication of impending trouble until failure of an equipment item due to mercury induced corrosion.
Detection of very low levels of mercury in natural gas streams has been verydifficult indeterminingwhich
streams are contaminated, and the degree of contamination.
Detection methods continue to improve, however. A number of available analyzers now claim
capability at the parts per trillion by volume (pptv) level. All of these methods rely on passing a sample

8. 8
stream through a mercury trap (dosimeter) over a long collection period, and then desorbingthe mercury
from the trap as a concentrated pulse into the detector17
.
Primary methods for elemental mercury detection in the gas include gold filament analyzers, cold
vapor atomic fluorescence (CVAF), peroxide scrubbing, and ICP/mass spec8
. CVAF is the preferred
method for laboratorywork, as it is verysensitive. One companyreported theygot accurate and consistent
results measuring mercury levels inthe feed and treated gas usingthe Jerome Model431 mercuryanalyzer
to less than0.001 g/Nm3
usingthe gold wire trap, provided that the sample lines are kept ultra-cleanover
the required long collectionperiod17
. Another companyinstalled a continuous online samplingsystemthat
could accuratelymeasure mercurydownto the 0.001 g/Nm3
level, and found that the Sir Galahad system
by P S Analytical Ltd.10.523 (atomic fluorescence spectrometry) unit could be adapted18
.
All of the methods mentioned above are gradually being improved to more accurately detect ppbv
levels inthe feed gas, and the pptvrequired inthe treated gas. However, theystillhave some problems. For
example, gold filament analyzers, which are the most frequently used detection instrument, have trouble
measuringorganometallic mercury, are sensitive to temperature changes, moisture, H2S, and mercaptans in
the gas, and cannot measure the gas at operating pressures.
For liquid analysis there are two known models: Nippon Instrument Corp. Model SP-3D (uses an
atomic absorption detector), and the PS AnalyticalLtd Merlinmodel(whichuses anelectronfluorescence
detector). One company had the analytical capability to analyze liquid samples including naphthas and
naturalgas condensates, and had developed a method to differentiate betweenthe various species20
.Levels
as low as 0.1 ppb wt. can be quantified.
The most accurate measurements should be done at operating conditions and over a prolonged
collection period8
. As a further complication to the situation, mercury levels in natural gas have been
reported to fluctuate bya factor offive over periods longer thaneight hours8
. Inaddition, whensamplesare

9. 9
collected in the field and brought to the lab, some of the mercury is adsorbed on the container walls,
resulting in lower readings.
MERCURY ATTACK ON EQUIPMENT
A large amount oflaboratorywork onmercurycorrosionis described inthe literature9,10
. Four major
methods of mercuryattack onaluminumand other structuralmetals have beendetermined. Amalgamation
occurs whenelementalmercurymakes a liquid metalsolutionwiththe base metal. Amalgamcorrosionuses
mercuryas a catalyst inthe presence ofwater to forma crystalline hydrated oxide ofthe base metal. Liquid
metalembrittlement (LME) involves the liquid diffusionofmercuryalonggrainboundaries inthe base metal
and can lead to rapid propagationofcracks. Mercuric galvanic corrosionaccelerates acid/base reactions
for a base metal in a corrosive service.
Amalgamcorrosionand LMEhave beenthe primarymeans ofmercuryattack inaluminumequipment
items that have failed. Both of these methods ofattack maybe prevented bykeepingthe temperature too
low for the reactions to proceed, or byanoxide coatingonthe surface ofthe base metal. However, frozen
mercurytends to accumulate incracks and crannies where the metalhas either not formed anoxide layer or
the oxide has cracked due to system temperature changes during a shutdown.
Areas of particular susceptibility are behind backing rings and along welds where the weld heat has
damaged the oxide and/or formed an aluminum/magnesium solution (Aluminum alloy 5083 is 4.5%
magnesium by weight) which is especially vulnerable to mercury attack. Uponlongshutdownperiods, or
during deriming operations, the mercury will melt and attack the base metal.
REMOVAL OF MERCURY FROM NATURAL GAS

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Many methods for preventing mercury attack have been tried. Measures have included surface
treatment of aluminum, making all aluminum equipment free draining for removal of liquid mercury, and
adding refrigeration units to ensure that the cold boxes stay cold and mercury remains frozen evenduring
sustained periods of plant shutdown. Work is inprogress10
onmethods ofremediationfor equipment that
has already been contaminated by using a chelating agent to remove concentrations ofelementalmercury.
However, operators have arrived at a consensus that it is best to remove the mercuryfromthe naturalgas
rather than preventing or remediating attack once the equipment has been contaminated.
Scavenging Elemental Mercury From The Vapor Phase: Scavenging elemental mercury and
organometallic compounds from the feedstock(s) of gas plants is a maturing technology for mercury
removal. Elemental mercury can be readily trapped by contact with sulfur based trapping agents. The
principle commercial trapping agents include sulfur, metal sulfides, silver and gold. The types of support
materials or carrier agents include activated carbon, alumina and other zeolite materials. Operating
temperatures range from ambient to 100 C, and at pressures up to 100 bar.
Elemental mercury in the gas phase is readilytrapped bysulfur based trappingmaterials whichfixes
the volatile mercuryinthe formofnon-volatile mercurysulfide (HgS). Most commonly, anactivated carbon
is chemically treated or impregnated with a mercury-fixing compound such as sulfur. The mercury is
chemisorbed onto the non-regenerative carbon which must be periodically replaced (typically every 3-4
years).
Activated carbonperforms best ongas streams that are 10-20 C above their hydrocarbondewpoint,
are not saturated withwater (relative humidityofthe gas is 70% or less), and whenthere is verylittle liquid
entrainment. Condensation of hydrocarbons and water would adversely affect the mercury removal
efficiency of the activated carbon and frequency of its change out.

11. 11
The mercury loading capacity of the activated carbon is 10-30wt% of the weight of the carbon,
dependingonthe manufacturer. The mercuryremovalefficiencyis greater than99%, below 0.01 g/Nm3
in
the treated gas. There are several activated carbon manufacturers/suppliers that offer a product for
elemental mercury removal including the following:
ALCOA Mersorb: Sulfur impregnated pelletized activated carbon.
Barneby & Sutcliffe Type CBII: Sulfur impregnated activated carbon.
Calgon Carbon Type HGRR
: Sulfur impregnated granular activated carbon.
CarboTech GmbH Type D47/4: Sulfur impregnated activated carbon.
Lurgi Type Desorex HGD.
Norit Type RBGH 3: Sulfur impregnated activated carbon.
Manufacturers/suppliers of the alumina carrier type include the following:
Procatalyse, CMG 273/275: Sulfur impregnated alumina molecular sieve. CMG 273 is used where the
natural gas is wet and there is liquid entrainment. CMG 275 is used for treatment ofnaturalgas where there
is little to no risk of liquid entrainment16
. Mercury content inthe treated gas is below 0.01 g/Nm3
. These
are not regenerable.
JGC Corp., MR-3: Metal sulfides supported on the surface of alumina. The manufacturer reports19
the
mercury content inthe treated gas is reduced to less than0.001 g/Nm3
, and mercuryadsorptionis as high
as 10 wt%. Mercuryis captured inthe formofmercurysulfide bycontact withthe metalsulfides adsorbent.
The captured mercury can be released and recovered at high temperatures with hydrogen.
ICI Katalco is marketingMERESPECTM
1157:a fixed bed chemicalabsorbent - mixed metaloxides with
cementitious binder. They report it to be a highly effective absorbent for both hydrogen sulfide and
elementalmercuryremoval, and it canbe used bothongaseous and liquid streams. ICI Katalco also reports

12. 12
this adsorbent reduces the mercurycontent below 0.01 g/Nm3
inthe treated gas. The spent adsorbentcan
be sent to a metal refiner/smelter for metals recovery, including the mercury.
UOP HgSIVTM
:Regenerative dualpurpose molecular sieve containingsome silver. The elementalmercury
(either in the gas or hydrocarbon liquid) amalgamates with the silver, and the rest of the HgSIV absorbs
water. Both the mercury and water are regenerated from the HgSIV adsorbent using conventional dryer
regeneration techniques. UOP reports this adsorbent to reduce the mercury content in the treated gas to
below 0.01 g/Nm3
. UOP also reports that the disposalrequirements for spent HgSIV are the same as for
conventional molecular sieves20
.
Removing organometallic mercury from the liquid phase. Less work has been done on the
problem of removal of organometallic mercury from liquid streams than that of the vapor phase removal.
The current leading approaches involve adsorption onto a carbon or molecular sieve, and the use of ion
exchange resins, such as:
ALCOA Mersorb LH: Impregnated pelletized activated carbon.
Calgon Type HGR-LH: Potassium iodide impregnated granular activated carbon.
Stamicarbon Ion Exchange Process6
: Ion exchange resin with thiol groups.
ICI Katalco MERESPECTM
1157:a fixed bed chemicalabsorbent - mixed metaloxides withcementitious
binder.
UOP HgSIVTM
: Silver containing regenerative molecular sieve.
Another method for organometallic mercuryremovalis the IFP/Procatalyse process12
which, through
hydrogenolysis of the organometallic compounds at moderate conditions on a catalyst bed reactor, yields
metallic mercury. The elementalmercurythus produced is thentrapped at a lower temperature ina second
reactor on a bed of the Procatalyse CMG-273 catalyst.
DISPOSAL ISSUES OF MERCURY CONTAMINATED WASTE

13. 13
Mercury contaminated waste from natural gas processing sites can include used catalysts (such as
spent activated carbon, alumina and molecular sieves) contaminated equipment, and contaminated soilfrom
spills and equipment leakage. The mercurycontaminated waste is classified as a D009 characteristic waste
and remediationis covered by40 CFR300 (Superfund). The spent carbonmercurycontent inthe formof
mercury sulfide varies anywhere from 4 wt% to as high as 30 wt%.
Some of the activated carbon suppliers will take the spent carbon back and a) reactivate it and
recover the mercury or b) dispose of it in an environmentally safe manner. They would also take care of
emptying, and rechargingthe adsorber. Other plant operators store the spent materialonsite for examplein
concrete bunkers where they can monitor mercury leakage.
Currently, the onlyapproved Best Demonstrated Available Technology(BDAT) bythe U.S.EPAfor
treatment of mercury contaminated waste is thermal roasting and vacuum retort13
. This treatment is
energy-intensive, costly, and time-consuming. In addition, the treatment usuallyrequires transportationof
the contaminated material or equipment to a central processing site, as mobile treatment units are not
designed to process large quantities of waste.
With the exception of the Stamicarbonionexchange resinprocess, UOP HgSIV, and JGCs MR-3,
the other commercialmercuryscavenger catalysts are nonregenerable. After a typicaloperatingperiod of
three to ten years, the entire mass of adsorbent, often more than5000 kg, withup to 20-30% mercuryby
mass, must be properly disposed.
WithUOPs HgSIV, most ofthe mercuryends up inthe regenerationgas. The mercuryconcentration
in the regeneration gas varies, depending on the regeneration time and temperature. It can peak above
4,000 g/Nm3
for a short period. Normally, the regeneration gas is cooled near ambient, and mixed with

14. 14
other gases. A small activated carbon bed can be added to remove the bulk of the mercury from the
regeneration gas.
Depending on the final cooling temperature, some of the mercury could condense with the water.
UOP reports this to be less than 0.5% of the inlet mercury20
, and that the solubilityofmercuryinwater is
about 25 ppbw. Anyadditionalamount above this would formits ownlayer whichcanbe readilyremoved
and sold. The last fugitive mercury can also be removed from the condensed water.
Disposalinvolves shippingto the processingsite, thermaltreatment, and sanitarylandfillingtheresidue.
Since LNG and many LPG production plants are overseas and mercury treatment facilities are in the
United States or Europe, transportation is expensive and faces a large number oflegalrequirements. The
thermal treating itself is expensive because it must be done in an inert atmosphere or under a vacuum, but
part of the cost can usually be recovered through purification and resale of liquid mercury.
Disposal of the residue must be in a sanitary lined landfill. Existingthermaltreatment processes can
treat up to 150 tonnes of waste per day with over 99.9% recovery of elemental mercury at an estimated
cost of $125 to $225 per ton of material, such as mercury scavenger catalyst or contaminated soil.
New Treatments. A number of new treatments show promise for helping meet mercury waste
specifications. Physical separation technologies based on the high density of mercury are used to treat
contaminated soils and have some effectiveness at bulk removal. However, physical separation cannot
remove the mercury that sorbs onto soil, or mercurychemicallybonded to scavenger catalysts. Biological
treatments use bacteria to concentrate organic mercurycompounds. Immobilizationtechnologiesreducethe
leachability of mercury into groundwater from contaminated soils. Chemicaltreatments show the greatest
promise of providing an alternative to thermal treatment. These technologies typicallyuse anacid to leach
the mercuryfromthe contaminated material. New approaches suggest usingan organic chelatingagentfrom
which the mercury can be recovered. None of the technologies described in this paragraph have yet
demonstrated the ability to achieve U.S. EPA standards.

15. 15
CONCLUSIONS
The presence of elemental and organometallic mercury in natural gas can lead to destruction of
cryogenic process equipment, contaminationofvessels, tanks, and soil, and hazards to operatingpersonnel.
Detection and prevention of mercury contamination is critical to the safe and reliable operation ofanygas
processing plant, particularly those in cryogenic gas processing.
Remediation of mercury contaminated soils and equipment is a costly and complicated procedure.
The current BDAT is thermal roasting or vacuum retort, whichis veryexpensive, time consuming, and not
as flexible as is necessary for treatment of contaminated equipment. However, new processes are under
development which show promise of solving some of the shortcomings of thermal treatment.

16. 16
References
1. Dolle, J., and D. Gilbourne, "LNG: Startup ofthe Skikda LNG Plant,"Chem. Eng. Progress, Vol.
72, Jan., 1976, p.39.
2. Leeper, J. E., "Mercury - LNG's Problem," Hydrocarbon Processing, Nov., 1980.
3. Wilhelm, S. M., and A. McArthur, "Removal and Treatment of Mercury Contamination at Gas
Processing Facilities," SPE 29721.
4. Shigemura, Y., T. Hagesawa, C.J. Cameron, P. Sarrazin, Y. Barthel, and P. Courty, "Complete
Arsenic and Mercury Removal from Liquid Hydrocarbon Feedstocks"
5. Bodle, W. W., A. Attari, and R. Serauskas, "Considerations for MercuryinLNG Operation,"LNG
6 Conference, 1980.
6. Frenken, P. and T. Hubbers, "Stamicarbon's Process for Mercury Removal from Liquid
Hydrocarbons," AIChE Spring Meeting, Houston, TX, U.S., 9 April, 1991.
7. ICI Katalco, PURASPEC product literature, ICI Chemicals & Polymers, Ltd., 1990.
8. Lewis, L. "Measurement of Mercury in Natural Gas Streams," GPA, 74th
AnnualConference, San
Antonio, Texas, U.S., March, 1995.
9. Nelson, D. R., "MercuryAttack ofBrazed AluminumHeat Exchangers inCryogenic Service,"GPA,
73rd
Annual Convention, New Orleans, Louisiana, U.S., March, 1994.
10. Wilhelm, S. M., and A. McArthur, "Methods to Combat Liquid Metal Embrittlement inCryogenic
AluminumHeat Exchangers,"GPA, 73rd
AnnualConvention, New Orleans, Louisiana, U.S., March,
1994.
11. Bourke, M. J., and A. F. Mazzoni, "The Roles ofActivated CarboninGas Conditioning,"presented
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12. "Mercury Removal from Natural Gas and Associated Condensates," Poster at the 9th
International
Conference on Liquefied Natural Gas, Nice, France, 17-20 Oct., 1989.

17. 17
13. Energy and Environmental Research Center, UND, "A Review of Remediation Technologies
Applicable to Mercury Contamination at Natural Gas Industry Sites," GRI Report 93/0099,
September, 1993.
14. UOP, E.S.Holmes, D.J.Kubek, J.Markovs, and E.P. Zbacnik, Process Improvements InAcid Gas
and Mercury Removal, AIChE 1994 Spring National Meeting, April 17-21, 1994.
15. IUPAC, Solubility Data Series, Vol. 29, Mercury In Liquids, Compressed Gases, Molten
Salts and Other Elements, Appendice IV, p. 240, 1987.
16. C.J. Cameron, Y. Barthel, and P. Sarrazin, Mercury Removal from Wet Natural Gas, GPA,73rd
Annual Convention, March 7-9, 1994, New Orleans LA.
17. UOP, J.Markovs and J.Corvini, Mercury Removal From Natural Gas & Liquid Streams,
Gas Conditioning Conference, March 4, 1996, Norman Oklahoma.
18. D.L.Lund, Amoco Exploration & Production, Causes and Remedies for Mercury Exposure to
Aluminum Coldboxes, GPA, 75th Annual Convention, March 13, 1996, Denver, Colorado.
19. JGC Corp., T.Goto, A.Puruta, K. Sato, High Efficiency MercuryRemovalAdsorbent For Natural
Gas LiquefactionPlant, 10thInternationalConference onLiquefied NaturalGas, 23-28 May, 1992,
Kuala Lumpur, Malaysia.
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1997.

18. 18

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