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TRACECOMPONENT
REMOVAL
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What is trace component removal
TCR involve the removal of componentsfrom a stream by mean of distillationandor adsorptionabsorption for removin!trace amo"nt of component from either the!as or li#"id
The trace component nat"ral !as incl"de$
%yro!en& O'y!en& Radon (NORM)&
Arsenic& %eli"m& Merc"ry& and *TE+&etc,
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O'y!enWhy do -e remove o'y!en from the !as
stream
.ncrease in pipeline corrosion
/e!radation of process chemicals0 amine
The present of O1 may e'ceedstrin!entpipeline speci2cation
Possible abandonmentif not controlled& hencelead to -aste of val"able reso"rces
%o- do -e remove O1
There are several technolo!y co"ld be "tili3edto remove the 41
5"ch as catalyst& membranes& and scaven!ers
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Catalyst
6se to convert the o'y!en to inert !as& by meancontactin! o'y!en containin! nat"ral !as -ith e,!&nitric o'ide "nder conditions s"7cient to prod"cenitro!en dio'ide
Operate reliable economical8e'ible
The problem is the addition of inert !as& -hich co"ld
p"sh !as o"t of pipeline,Membrane
Ma9e "se of membrane separation "nit so as toseparate o'y!en from feed stream
Only permittin! a si3e molec"lar of methane to passthro"!h to 8o- to the stream -hile o'y!en is bloc9ed
and 8o- to the -aste stream prod"ce a 2rst prod"ct stream enriched -ithmethane
and a -aste stream havin! a hi!h molec"larconcentration of o'y!en than feed stream
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5caven!ers
Ma9e "se of noble metals& s"ch asplatin"mor palladi"mto converttheo'y!en to carbondio'ide and -ater
This o'y!en scaven!in! is cond"cted
after the removal of s"lf"r compo"ndsince most adsorbent for o'y!enremoval are poisoned by many s"lf"rcontainin! compo"nd
The operation is reliable ho-evercostcan be hi!h
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MERC6R:
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Varyin! level -orld-ide (4 to ;44
Lo- vapori3in! temperat"re (=> o? to @ o?) Amal!amate (alloy formation)
Reason of removal
Corrosion on do-n stream heat e'chan!er
Mechanical fail"re d"e to
Merc"ry vapor that corrode pipelines and valves, Catalyst poisin! problem in the process plant
Environmental poll"tion
%ealth eBect Mood chan!es
Memory loss
?ine sha9in!Tin!lin!
idney disease
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/etection method
Colorimetric analysis
Cold vapor atomic absorption spectrophotometry Amal!amation collection,
Conventional merc"ry removal
Adsorption on activated carbon React -ith s"lf"r to form merc"ric s"l2de
/ra-bac9 No commercial "se of prod"ced prod"ct
disposes can only by comb"stion,
Adsorption on s"lf"r impre!nated carbon ( chemiDsorption) Loss of merc"ry d"e to s"blimation and dissol"tion in hydrocarbon
Operators health problems
Amal!amation -ith val"able metal (silver) EBective removal and potential of re!eneration of silver
Not s"it -ith the presence of %15
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?actor aBectin! merc"ry removal e7ciency
Composition of !as
Presence of hi!her hydrocarbon
Operatin! temperat"re and press"re Activated carbon characteristic
Concentration of merc"ry vapor
Presence of -ater
as 8o- rate
Contact time
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*TE+
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/an!er
%"man carcino!en that promote le"9emia
Reprod"ction and development eBect eBect blood& 9idney and liver
Respiratory and cardiovasc"lar problems
d"e to eBect on central nervo"s systems .n !as processin!
Poll"te to-ard environments
Potential free3in! in cryo!enic "nits,
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Conventional removal .ncinerated at elevated temperat"re,
Prod"ce CO1
F444 G FH44 o?
Costly
sol"tion approach AdI"stment of plant operatin! conditions to minimi3e the #"antity of *TE+ in the
!lycol absorber oB !as,Temperat"re of rich amine
%i!h temperat"re lead to lo-er absorption,
Press"re of contactor col"mn
Circ"lation rate type of amine
Lo-er circ"lation rate& lo-er absorption
Amine concentration
Lo- concentration& lo- absorption
*"rnin! of the still of !ases before ventin! Condensation of the oB !ases and recovery of *TE+ as a li#"id
Adsorption of the *TE+ on a carbon adsorbent,
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6se of -ater
%i!h sol"bility of ben3ene in -ater
Ass"me *TE+ as p"rely ben3ene
%i!h 8o- rate of -ater needed (do"bled)
Need addition of adsorbent to separate *TE+ from -ater, Prior for recyclin! or re"se of -ater
Methane loss d"e methane sol"bility
Activated carbon
Readily available
Lo- cost
Replaced after 1 r"n cycle Lo- re!eneration ability
5ilica aero!el (adsorbent)
*ecome cheaper in prod"ction
%i!h pro'imity to-ard aromatic compo"nds,
Can be "se "p to F> cycles,
%ydrophobic (repel -ater)
Less adsorption to-ard methane
M"ch cost eBective -hen placed at the bac9 of the "nit
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%ydro!en G contain only in small concentration normallydo not ca"se problem
Radon ( NORM ) D Lo- concentration G not harmf"l
Arsenic G can s"ccessf"lly removed "sin! adsorptionprocess
%eli"m G very val"able prod"ct Lo- concentration (less than HJ)
/irectly recovered after !as processin! and f"rther p"ri2ed at otherprocessin! plant,