selection of separation processes

8/18/2019 Selection of Separation Processes

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Chapter 1. Separation Processes

2012. 1학기


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분리공정의 중요성

Energy Consumption• 분리공정이 화학 / 생물 공정에 !" #$ 에%&' (

)*+ .• ,-/ 0 / 23이 4요5 .

67!!8 -9의 생:• ; : enantiomerically pure components

• Softenon : (R-enantiomer), ?@ (S-enantio

mer)• Aspartame : AB (S, S) , B (R, R)• Limonen : DEF (S), GH&F (R)


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Separations

Separations• Enrichment

• Concentration

• urification

• Refining

• !solation

Separations are important to chemist an" chemical engineers• Chemist : Small scale (Analytical separation metho"s)

• Chemical Engineers : Economical, large scale metho"s

#


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!n"ustrial Chemical rocesses

$

• Natural raw material

• Plant or animal matter

• Chemical intermediate

• Chemicals of commerce

• Waste products

Feed

• Batchwise

• Continuous

• Semicontinuous

Mode of Operation

• Key Operation

• Reaction

• Separation

• Auxiliary Operation

• Heat Wor!

• "ixin#$ %i&idin#

• Si'e reduction

Operation


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%ypothetical &s. !n"ustrial rocesses

• Simple ,hypothetical process is not possi'le• !mpurities in the fee"

• Si"e Reactions

• Separation processes are important in real in"ustrial application


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echanism of Separation

i*ing : Spontaneous, natural process Separation : +ot spontaneous process

• Reuire energy (heat / or)

uestion : 0hy 1

2


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3eneral Separation 4echniue

Separation 'y hase Creation• Energy (heat/or) ' 이>IJ KLM NO Q• R , T정화

Separation 'y hase A""ition• - # 의 물U (SA : ass Separating Agent) ' V!IJ 분리• >- VW

Separation 'y 5arrier• 5arrier (mem'rane X ) O 이>IJ 분리• Y분리

Separation 'y Soli" Agent• Z[ 성U이 \]^ 6_' `>• , b리d

Separation 'y 6orce 6iel" or 3ra"ient• 중 , fg , ?" XO `>• fg 분리? , 7

8


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Classification of Separation 4echniues

9

5arrier

6orce fiel"or gra"ient

(eed

Phase )

Phase *

+i, By Phase Creation

(eed

Phase )

Phase *

(eed

Phase )

Phase *

(eed

Phase )

Phase *

(eed

Phase )

Phase *

+ii, By Phase Addition

+iii , By Barrier

+i-, By Solid A#ent +-i, By (orce (ield or .radient

"SA

ass Separating Agent


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ri&ing 6orce of Separation :3ra"ient of Concentration

• Rate of Separation : how fast ? • 3o&erne" 'y mass transfer

• E*tent of Separation : how far ? • Limite" 'y thermodynamics

•

roperties of !mportance"olecular Properties /hermodynamic and /ransport Properties

"olecular Wei#ht

-an der Waals -olume

-an der Waals Area

"olecular Shape +Accentric (actor,

%ipole "omentPolari'a0ility

%ielectric Constant

1lectric Char#e

Radius of .yration

-apor Pressure

Solu0ility

Adsorpti&ity

%iffusi&ity

;

• Handbooks• Journals• Electronic Databases• Commercial Process Simulators


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Separation 5y hase A""ition or Creation -

>>

@/L

L

L

%istillation

+Heat transfer +1SA, or sometimes wor! transfer,

• When the &olatility difference

amon# species are not sufficiently

lar#e

• "ost widely used industrial

separation techni3ue• "ultiple contact 0etween counter

current flow of -4 in trays

+sta#es, 5

Rectifyin# section

Strippin# section

Condenser

Re0oiler

Reflux

Re0oil


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istillation 4oer

>


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Separation 5y hase A""ition or Creation - #

>#

@/L

L

L

A'eotropic %istillation

4i3uid entrainer +"SA,

and Heat /ransfer +1SA,

Recycle MSA

Makeup MSA

Reco&ery of acetic acid from water

usin# n20utyl acetate


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Separation 5y hase A""ition or Creation - $

>$

MSA (L)

L>

L

L>

4i3uid 6 4i3uid 1xtraction

4i3uid sol&ent+"SA,

Reco&ery of Aromatics

MSA2 (L)

L

L

L

4i3uid24i3uid 1xtraction

+/wo Sol&ent,

7se of Propane and Cresylic acid as sol&ents to separate

paraffins from aromatics and naphthenes

MSA1 (L)


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Separation 5y hase A""ition or Creation -

>

%ryin# 1&aporation Crystalli'ation %esu0limation

@ (@)

L/(S) S

@

L

(@)

L L

S

@

S

L @

Removal of water from PVCEvaporationof water from

ater ! "rea

Cry#talli$ation o p%&ylenefrom m%&ylene

Recovery of p't'alic an'yrie

eat tran#fer (ESA)

eat tran#fer (ESA) eat tran#fer (ESA) eat tran#fer (ESA)


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CrystalliBer

>2


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Separation 5y hase A""ition or Creation - 2

>8

4eachin# +4i3uid2Solid 1xtraction, (oam (ractionation

S

SA (L)

S

L

L

SA (g)

L (foam)

@

L

E*traction of #u+ar u#in+ 'ot water

Li,ui Solvent

Recovery of eter+ent from water #oln-

.a# /u00le# (MSA)

etergent ten" torise ith gas 'u''le


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Separation 'y 'arrier - >

>;

Osmosis Re&erse Osmosis %ialysis

L

L

L

L

L

Nonporous mem0rane Nonporous mem0rane Porous mem0rane

Concentration #radient Pressure .radient Concentration .radient

Pressure .radient%esalination of sea water Reco&ery of caustic

from hemicellulose

sol&ent

sol&ent

smallersolute


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Separation 'y 'arrier -

?

"icrofiltration 7ltrafilration Per&aporation

L

L

L

L

@

"icroporous mem0rane "icroporous mem0rane Nonporous mem0rane

Pressure #radient Pressure .radient Pressure .radient

Separation of whey from

cheese

Separation of a'eotropic

mixtures

L

L

L

Remo&al of 0acterial

(rom drin!in# water

L

?.?->? µm > – ? nm

sol&entsol&ent gas (e&aporation)


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Separation 'y 'arrier - #

>

.as permeation4i3uid "em0rane

@

@

@

@/L

@/L

Nonporous mem0rane4i3uid mem0rane

Pressure .radient Pressure .radient

Hydro#en enrichment Remo&al of hydro#en sulfide

@/L

gas

3as mi*ture

Liui" layer


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Liui" em'rane


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Separation 'y soli" agent

$

Adsorption Chromato#raphy 8on 1xchan#e

Solid Adsor0ent Solid adsor0ent or li3uid

Adsor0ent on solid support

Resin with ion2acti&e sites

Separation of xylene isomers

and ethyl0en'ene

%eminerali'ation of water

Purification of

p2xylene

@/L

@/L

@/L @/L

@/L

L

L

L


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Separation 'y soli" agent

• A"sorption• A"sor'ent

• Acti&ate" car'on

• Aluminum o*i"e

• Silica gel

• Deolite a"sor'ents (olecularsie&e)

• A"sorption / Regeneration

• Regeneration metho"s• 4hermal Sing (4SA)

• ressure Sing (SA)

• !nert purge stripping• isplacement "esorption

%y"rogen SA nits


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Centrifugation

8


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Electro"ialysis

9


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Electrophoresis ( ?jk )

;

"#in+ ifferent mi+ration velocitie# of c'ar+e colloial or#u#pene #pecie# in a electrical fiel

Application /ioc'emical#

6i l" 6l S ti


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6iel" 6lo Separation6iel" 6lo 6ractionation (666)

#?

Micromolecular ancolloial material#


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Component Reco&eries an" ro"uct urity

• Separation process• +o reaction

• Continuous an" stea"y state

i : 1 ~ C Number of Components

p : 1~ N Product phases F : feed

)()1()()!()1(

1

)()(

""" N

i

N

iiii

N

p

p

i

F

i nnnnnnn +++++== −

=∑

#>


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E*ample %y"rocar'on Reco&ery lant

#

urpose :ro"uction of polymers

- - 5….

S li 6 i " S li R i


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Split 6raction an" Split Ratio

• Split fraction ( ? >)

• Split ratio ( ? &ery large &alue)

)(

#

)1(

#

# F

k i

k i

k in

nSF =

)1( #

#

)!(

#

)1(#

#

k i

k i

k i

k i

k iSF

SF

n

nSR

−==

##

i : component

k : separator

(F) : feed

(1) : first product (ex: top product)

(2) : second product (ex : bottom product)

성분 i 의 pro"uct /fee"

성분 i 의 top / 'ottom


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Separation oer

)1$()1(

$

$

$)!()1(

)!()1(

#

ji

ji

j

i

j j

ii ji

SF SF

SF SF

SR

SR

C C

C C SP

−−===

%e&'component split Column SPSeparation Po(er

nC)H1* $ iC+H1! C1 1,"1

CH-$iC)H1* C! ,1*

iC)H1*$nC)H1* C ,,".

#$

l i f i'l i


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Selection of 6easi'le Separation

Selection of a 'est separation processes• Selection among a num'er of feasi'le can"i"ates

• 4o or more operations may 'e the 'est

!mportant 6actors that influence the selectionof feasi'le separation operations

• 6ee" con"itions

• ro"uct con"itions

• roperty "ifferences

• Characteristics of separation

#

6 h ! fl h S l i f 6 i'l


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6actors that !nfluence the Selection of 6easi'leSeparation Fperation

(eed condition Compositions

(low rate

/emperature

Pressure

Phase state

Product conditions Re3uired purities of products

/emperatures

Pressures

Phase states

Property differences "olecular

/hermodynamic

/ransport

Characteristics of separationoperation

1ase of scale2up1ase of sta#in#

/$ P$ Phase2state re3uirements

Physical si'e limiation

1ner#y re3uirement

#2

"ost important

Can 0e altered 0y pump$

Compressor$ heat exchan#ers$ 9

4echnological an" se aturity of Separation rocess


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4echnological an" se aturity of Separation rocesses

#8

Separation/y /arrier

Separation 0y Soli a+ent

Creation of Aition ofSecon P'a#e Cheap

E*pensi&e

E f S l


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Ease of Scale-up

#9

G H ?? I H >? I

selection of separation processes

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