27
c 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002/14356007.b03 06 Liquid – Liquid Extraction 1 Liquid – Liquid Extraction Eckart M ¨ uller, Frankfurt a. Main, Germany (Chaps. 1 and 2) Rosemarie Berger, Ludwigshafen, Germany (Chaps. 3 and 4) Eckhart Blass, Technische Universit¨ at M ¨ unchen, M ¨ unchen, Germany (Chaps. 1 – 4, Sections 5.1 and 5.2) Domien Sluyts, Bayer AG, Antwerpen, Belgium (Section 5.3) 1. Fundamentals and Fields of Appli- cation .................... 2 2. Thermodynamic Fundamentals ... 4 2.1. Graphic Representation of Phase Equilibria ................. 4 2.1.1. Triangular Diagrams ........... 4 2.1.2. Other Graphic Representations .... 6 2.2. Measuring Methods of Phase Equi- libria .................... 7 2.3. Empirical Correlations of Phase Equilibria ................. 9 2.4. Selection of Solvent ........... 10 2.5. Calculation of Theoretical Stages . 11 2.5.1. Selection of Calculation Methods ... 11 2.5.2. Specific Methods ............. 11 2.5.3. Evaluation of Stage-Number Calcula- tion for Process Design ......... 13 3. Apparatus ................. 15 3.1. Survey ................... 15 3.1.1. Columns without Energy Input .... 15 3.1.2. Pulsed Columns .............. 17 3.1.3. Columns with Rotating Internals ... 20 3.1.4. Mixer – Settlers .............. 21 3.1.5. Centrifugal Extractors .......... 23 3.2. Fluid-Dynamic Fundamentals .... 24 3.2.1. Problems and Process Strategy .... 24 3.2.2. Operating Characteristics of Pulsed Columns and Columns with Rotating Internals .................. 25 3.2.3. Fluid Dynamic Calculation Methods . 28 3.3. Apparatus Design ............ 30 3.3.1. Internals and Operating Conditions .. 30 3.3.2. Column Diameter ............. 31 3.3.3. Column Height .............. 32 3.4. Criteria for Equipment Selection .. 32 4. Phase-Separation Equipment .... 36 4.1. Gravity Settlers without Inserts .. 36 4.2. Settlers with Coalescing Aids .... 37 5. Liquid – Liquid Extraction Pro- cesses .................... 41 5.1. General .................. 41 5.2. Combined Processes of Extraction and Distillation ............. 43 5.3. Reactive Extraction ........... 44 5.3.1. Introduction ................ 44 5.3.2. Extraction Mechanism of Different Types of Solvent ............. 45 5.3.3. Uses ..................... 48 5.3.4. Setting up an Extraction System ... 49 5.3.5. Diluents and Modifiers ......... 50 6. References ................. 51 Symbols 2 a Pulsing amplitude, m A key component of the phase from which the solute is extracted B key component of the phase into which the solute is extracted c i constants C transferred component d i hole or packing diam- eter, m d p particle diameter, m d 32 Sauter mean drop di- ameter, m D column diameter, m D R rotor diameter, m D distribution coefficient E=K ˙ m s / ˙ m F extraction factor f pulsing frequency, s 1 g acceleration due to gravity, m/s 2 G i coefficients in empiri- cal correlations of the distribution coefficient 2 Liquid – Liquid Extraction h compartment height, m H height of column, m HETS height equivalent of a theoretical stage, m k=y c /x c distribution ratio of transferred component (in terms of mass frac- tion) K=Y C /X C distribution ratio of transferred component (in terms of loading) K p plait point m jk mass of component j in phase or flow k ( j = A, B, C; k = F, R, S, E), kg m k = m Ak + m Bk + m Ck total mass of phase or flow k (k = F, R, S, E), kg ˙ m mass flow, kg/h n s revolutions of stirrer, s 1 n number of stages NTS number of theoretical stages s column cross section, m v superficial velocity, m 3 m 2 h 1 or m/s v m S / ˙ m F extractant ratio v p individual drop veloc- ity, m/s v r slip velocity (Eq. 9), m/s x C mass fraction of C in A-rich phase X C = x/(1 x) loading of A-rich phase with component C, kg/kg y C mass fraction of C in B-rich phase Y C = y/(1 y) loading of B-rich phase with C, kg/kg Greek symbols ε holdup, m 3 /m 3 η dynamic viscosity, Pa · s × 10 3 density, kg/m 3 σ interfacial tension, N/m × 10 3 ϕ free area Dimensionless Groups Ar = d 3 P g c Δ/η 2 c Archimedes number Fr R = N 2 D R /g Froude number Re p = v p d p /v d Particle Reynolds number K L = 2 c σ 3 / ( Δ4 c ) Characteristic num- ber of liquid Subscripts A key component of the phase from which the solute is extracted B key component of the phase into which the solute is extracted C transferred substance (solute) c continuous phase d dispersed phase E extract f flooding F feed i internals (characteristic size) o organic p drop (particle) R raffinate S solvent 1 pilot scale 2 large scale 1. Fundamentals and Fields of Application Liquid – liquid extraction or solvent extraction is a separation process which is based on the different distribution of the components to be separated between two liquid phases. It depends on the mass transfer of the component to be ex- tracted from a first liquid phase to a second one. Definitions. The phases form definite con- tact areas and cannot or can only to a limited extent mix with one another on account of their properties. The phases are composed of indi- vidual substances, so-called components, and flow as liquid streams through the extractor (see Fig. 1). Phases are liquid streams that are in equi- librium with each other. Generally, more than three components are involved in an extraction. To make the descrip- tion of the problem simpler, key components are

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c ©2005

Wil

ey-V

CH

Ver

lag

Gm

bH

&C

o.

KG

aA,W

einhei

m10.1

002/1

4356007.b

03

06

Liq

uid

–Liq

uid

Extr

action

1

Liq

uid

–L

iqu

idE

xtr

act

ion

Eckart

Mu

ller

,F

rankfu

rta.

Mai

n,G

erm

any

(Chap

s.1

and

2)

Rosem

arie

Berger

,L

udw

igsh

afen

,G

erm

any

(Chap

s.3

and

4)

Eckh

art

Blass,T

echnis

che

Univ

ersi

tat

Munch

en,M

unch

en,G

erm

any

(Chap

s.1

–4,

Sec

tions

5.1

and

5.2

)

Dom

ien

Slu

yts,B

ayer

AG

,A

ntw

erpen

,B

elgiu

m(S

ecti

on

5.3

)

1.

Fu

nd

am

enta

lsan

dF

ield

sof

Ap

pli

-

cati

on

....................

2

2.

Th

erm

od

yn

am

icF

un

dam

enta

ls...

4

2.1

.G

rap

hic

Rep

rese

nta

tion

of

Ph

ase

Eq

uil

ibri

a.................

4

2.1

.1.

Tri

angula

rD

iagra

ms

...........

4

2.1

.2.

Oth

erG

raphic

Rep

rese

nta

tions

....

6

2.2

.M

easu

rin

gM

eth

od

sof

Ph

ase

Eq

ui-

lib

ria

....................

7

2.3

.E

mp

iric

al

Corr

elati

on

sof

Ph

ase

Eq

uil

ibri

a.................

9

2.4

.S

elec

tion

of

Solv

ent

...........

10

2.5

.C

alc

ula

tion

of

Th

eore

tica

lS

tages

.11

2.5

.1.

Sel

ecti

on

of

Cal

cula

tion

Met

hods

...

11

2.5

.2.

Spec

ific

Met

hods

.............

11

2.5

.3.

Eval

uat

ion

of

Sta

ge-

Num

ber

Cal

cula

-

tion

for

Pro

cess

Des

ign

.........

13

3.

Ap

para

tus

.................

15

3.1

.S

urv

ey...................

15

3.1

.1.

Colu

mns

wit

hout

Ener

gy

Input

....

15

3.1

.2.

Puls

edC

olu

mns

..............

17

3.1

.3.

Colu

mns

wit

hR

ota

ting

Inte

rnal

s...

20

3.1

.4.

Mix

er–

Set

tler

s..............

21

3.1

.5.

Cen

trif

ugal

Extr

acto

rs..........

23

3.2

.F

luid

-Dyn

am

icF

un

dam

enta

ls....

24

3.2

.1.

Pro

ble

ms

and

Pro

cess

Str

ateg

y....

24

3.2

.2.

Oper

atin

gC

har

acte

rist

ics

of

Puls

ed

Colu

mns

and

Colu

mns

wit

hR

ota

ting

Inte

rnal

s..................

25

3.2

.3.

Flu

idD

ynam

icC

alcu

lati

on

Met

hods

.28

3.3

.A

pp

ara

tus

Des

ign

............

30

3.3

.1.

Inte

rnal

san

dO

per

atin

gC

ondit

ions

..

30

3.3

.2.

Colu

mn

Dia

met

er.............

31

3.3

.3.

Colu

mn

Hei

ght

..............

32

3.4

.C

rite

ria

for

Eq

uip

men

tS

elec

tion

..

32

4.

Ph

ase

-Sep

ara

tion

Eq

uip

men

t....

36

4.1

.G

ravit

yS

ettl

ers

wit

hou

tIn

sert

s..

36

4.2

.S

ettl

ers

wit

hC

oale

scin

gA

ids

....

37

5.

Liq

uid

–L

iqu

idE

xtr

act

ion

Pro

-

cess

es....................

41

5.1

.G

ener

al

..................

41

5.2

.C

om

bin

edP

roce

sses

of

Extr

act

ion

an

dD

isti

llati

on

.............

43

5.3

.R

eact

ive

Extr

act

ion

...........

44

5.3

.1.

Intr

oduct

ion

................

44

5.3

.2.

Extr

acti

on

Mec

han

ism

of

Dif

fere

nt

Types

of

Solv

ent

.............

45

5.3

.3.

Use

s.....................

48

5.3

.4.

Set

ting

up

anE

xtr

acti

on

Syst

em...

49

5.3

.5.

Dil

uen

tsan

dM

odifi

ers

.........

50

6.

Ref

eren

ces

.................

51

Sy

mb

ols

2a

Pu

lsin

gam

pli

tud

e,m

Akey

com

po

nen

to

fth

ep

has

efr

om

wh

ich

the

solu

teis

extr

acte

dB

key

com

po

nen

to

fth

ep

has

ein

tow

hic

hth

eso

lute

isex

trac

ted

c ico

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ants

Ctr

ansf

erre

dco

mp

on

ent

di

ho

leo

rp

ack

ing

dia

m-

eter

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dp

par

ticl

ed

iam

eter

,m

d32

Sau

ter

mea

nd

rop

di-

amet

er,

mD

colu

mn

dia

met

er,

mD

Rro

tor

dia

met

er,

mD

dis

trib

uti

on

coef

fici

ent

E=

Km

s/m

Fex

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nfa

cto

rf

pu

lsin

gfr

equ

ency

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1

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rati

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eto

gra

vit

y,m

/s2

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coef

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ents

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pir

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rrel

atio

ns

of

the

dis

trib

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coef

fici

ent

2Liq

uid

–Liq

uid

Extr

action

hco

mp

artm

ent

hei

gh

t,m

Hh

eig

ht

of

colu

mn

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HE

TS

hei

gh

teq

uiv

alen

to

fa

theo

reti

cal

stag

e,m

k=

yc/x

cd

istr

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tio

of

tran

sfer

red

com

po

nen

t(i

nte

rms

of

mas

sfr

ac-

tio

n)

K=

YC

/XC

dis

trib

uti

on

rati

oo

ftr

ansf

erre

dco

mp

on

ent

(in

term

so

flo

adin

g)

Kp

pla

itp

oin

tm

jk

mas

so

fco

mp

on

ent

jin

ph

ase

or

flow

k(j=

A,B

,C;k

=F,R

,S

,E),

kg

mk

=m

Ak

+m

Bk

+m

Ck

tota

lm

ass

of

ph

ase

or

flow

k(k

=F,R

,S,E

),k

gm

mas

sfl

ow

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g/h

ns

revo

luti

on

so

fst

irre

r,s−

1

nn

um

ber

of

stag

esN

TS

nu

mb

ero

fth

eore

tica

lst

ages

sco

lum

ncr

oss

sect

ion

,m

vsu

per

fici

alvel

oci

ty,

m3

m−

2h−

1o

rm

/sv

=m

S/m

Fex

trac

tan

tra

tio

v pin

div

idu

ald

rop

vel

oc-

ity,

m/s

v rsl

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oci

ty(E

q.

9),

m/s

xC

mas

sfr

acti

on

of

Cin

A-r

ich

ph

ase

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=x/(

1−

x)

load

ing

of

A-r

ich

ph

ase

wit

hco

mp

on

ent

C,

kg

/kg

yC

mas

sfr

acti

on

of

Cin

B-r

ich

ph

ase

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=y/(

1−

y)

load

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of

B-r

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ph

ase

wit

hC

,k

g/k

g

Gre

eksy

mb

ols

εh

old

up

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3/m

3

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yn

amic

vis

cosi

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Pa·s×

10−

3

d

ensi

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kg

/m3

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terf

acia

lte

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on

,N

/m×

10−

3

ϕfr

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ea

Dim

ensi

on

less

Gro

up

s

Ar

=d3 Pgc∆

/η2 c

Arc

him

edes

nu

mb

erF

r R=

N2D

R/g

Fro

ud

en

um

ber

Re p

=v p

dp/v d

Par

ticl

eR

eyn

old

sn

um

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KL

=2 cσ

3/

(

∆gη4 c

)

Ch

arac

teri

stic

nu

m-

ber

of

liq

uid

Su

bsc

rip

ts

Akey

com

po

nen

to

fth

ep

has

efr

om

wh

ich

the

solu

teis

extr

acte

dB

key

com

po

nen

to

fth

ep

has

ein

tow

hic

hth

eso

lute

isex

trac

ted

Ctr

ansf

erre

dsu

bst

ance

(so

lute

)c

con

tin

uo

us

ph

ase

dd

isp

erse

dp

has

eE

extr

act

ffl

oo

din

gF

feed

iin

tern

als

(ch

arac

teri

stic

size

)o

org

anic

pd

rop

(par

ticl

e)R

raffi

nat

eS

solv

ent

1p

ilo

tsc

ale

2la

rge

scal

e

1.

Fu

nd

am

enta

lsan

dF

ield

sof

Ap

pli

cati

on

Liq

uid

–li

qu

idex

trac

tio

no

rso

lven

tex

tra

ctio

n

isa

sep

arat

ion

pro

cess

wh

ich

isb

ased

on

the

dif

fere

nt

dis

trib

uti

on

of

the

com

po

nen

tsto

be

sep

arat

edb

etw

een

two

liq

uid

ph

ases

.It

dep

end

so

nth

em

ass

tran

sfer

of

the

com

po

nen

tto

be

ex-

trac

ted

fro

ma

firs

tli

qu

idp

has

eto

ase

con

do

ne.

Defi

nit

ion

s.T

he

ph

ases

form

defi

nit

eco

n-

tact

area

san

dca

nn

ot

or

can

on

lyto

ali

mit

edex

ten

tm

ixw

ith

on

ean

oth

ero

nac

cou

nt

of

thei

rp

rop

erti

es.

Th

ep

has

esar

eco

mp

ose

do

fin

di-

vid

ual

sub

stan

ces,

so-c

alle

dco

mp

on

ents

,an

dfl

ow

asli

qu

idst

ream

sth

rou

gh

the

extr

acto

r(s

eeF

ig.1

).P

has

esar

eli

qu

idst

ream

sth

atar

ein

equ

i-li

bri

um

wit

hea

cho

ther

.G

ener

ally

,m

ore

than

thre

eco

mp

on

ents

are

invo

lved

inan

extr

acti

on

.T

om

ake

the

des

crip

-ti

on

of

the

pro

ble

msi

mp

ler,

key

com

po

nen

tsar

e

Page 2: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

3

defi

ned

.T

he

feed

toa

liq

uid

–li

qu

idex

trac

tio

nis

the

solu

tio

nth

atco

nta

ins

the

com

po

nen

tsto

be

sep

arat

ed.

Th

ekey

com

po

nen

to

fth

isli

qu

idp

has

e(t

he

ph

ase

fro

mw

hic

hth

eso

lute

isex

-tr

acte

d)

isca

lled

A,

the

tran

sfer

red

sub

stan

ce(t

he

solu

te)

C.

Th

e(e

xtra

ctio

n)

solv

ent

isth

eli

qu

idad

ded

toth

ep

roce

ssto

extr

act

the

sub

-st

ance

Cfr

om

the

feed

.T

he

solv

ent

can

be

the

pu

reco

mp

on

ent,

B,

bu

tu

sual

lyco

nta

ins

smal

lq

uan

titi

eso

fC

and

A,b

ecau

seth

eso

lven

tis

usu

-al

lyre

cycl

edfr

om

are

cover

ysy

stem

.T

he

sol-

ven

tp

has

ele

avin

gth

eex

tra

cto

ris

the

extr

act

.

Th

eex

trac

tco

nta

ins

mai

nly

Ban

dth

eex

trac

ted

com

po

nen

tC

bu

tal

sosm

allq

uan

titi

eso

fA

.Th

era

ffin

ate

isth

eli

qu

idp

has

ele

ftfr

om

the

feed

afte

rb

ein

gco

nta

cted

by

the

extr

acti

on

solv

ent;

itis

com

po

sed

mai

nly

of

A,bu

tg

ener

ally

smal

lq

uan

titi

eso

fth

eex

trac

ted

com

po

nen

tC

and

sol-

ven

tB

.

Co

mp

ari

son

wit

hD

isti

lla

tio

n.

Liq

uid

–li

q-

uid

extr

acti

on

has

sim

ilar

itie

sw

ith

dis

till

atio

n.

Inb

oth

case

sth

esu

bst

ance

sto

be

sep

arat

edh

ave

con

cen

trat

ion

rati

os6=

1in

the

two

ph

ases

.In

the

case

of

dis

till

atio

nth

ese

con

dp

has

e(t

he

vap

or

ph

ase)

isfo

rmed

excl

usi

vel

yfr

om

the

com

po

-n

ents

ofth

ein

itia

l(li

qu

id)p

has

e,w

ith

extr

acti

on

an

ewsu

bst

ance

,th

e(e

xtr

acti

on

)so

lven

t,m

ust

be

add

edto

form

the

seco

nd

(liq

uid

)p

has

e.T

he

solv

ent

ente

rsin

toth

em

ater

ial

bal

ance

of

the

pro

cess

and

its

beh

avio

rto

war

ds

the

sub

stan

ces

tob

ese

par

ated

isd

ecis

ive

for

the

sep

arat

ion

pro

cess

.G

ener

ally

,th

eex

trac

ted

sub

stan

ceis

sep

a-ra

ted

fro

mth

eso

lven

tb

yd

isti

llat

ion

and

the

solv

entB

isre

cycl

edto

the

extr

acto

r.S

om

etim

esth

ese

lect

ive

acti

on

of

the

solv

ent

isu

sed

inth

ed

isti

llat

ion

wh

ich

gen

erat

esth

ere

flu

xfo

rth

eex

trac

tio

n,

e.g

.,ex

tra

ctiv

ed

isti

lla

tio

n(e

xtr

ac-

tio

no

far

om

atic

com

po

un

ds,

see

Sec

tio

n5

.2)

or

aze

otr

op

icd

isti

lla

tio

n(e

xtr

acti

on

of

acet

icac

id).

Inth

eex

trac

tio

no

fm

etal

salt

s(s

eeS

ec-

tio

n5

.3)

the

pu

rity

iso

ften

ach

ieved

by

adju

st-

ing

the

pH

.E

xtr

acti

on

isan

iso

ther

mal

pro

cess

,n

orm

ally

carr

ied

ou

tat

amb

ien

tte

mp

erat

ure

and

pre

ssu

re.

Co

mp

ari

son

wit

hA

bso

rpti

on

.In

bo

thab

-so

rpti

on

and

extr

acti

on

solv

ents

are

use

dw

hic

har

ere

cycl

edan

dth

ereb

yta

ke

up

the

req

uir

edco

mp

on

ents

sele

ctiv

ely

and

then

rele

ase

them

agai

n.

Sel

ecti

on

of

the

most

suit

able

solv

ents

ther

efo

rep

lay

san

imp

ort

ant

role

inth

ed

esig

no

fth

etw

ose

par

atio

np

roce

sses

.

Ap

pli

cati

on

so

fL

iqu

id–

Liq

uid

Ex

tra

c-ti

on

.L

iqu

id–

liq

uid

extr

acti

on

isp

rim

aril

yap

-p

lied

wh

ere

dir

ect

sep

arat

ion

met

ho

ds

such

asd

isti

llat

ion

and

cry

stal

liza

tio

nca

nn

otb

eu

sed

or

are

too

cost

ly.

Liq

uid

–li

qu

idex

trac

tio

nis

also

emp

loy

edw

hen

the

com

po

nen

tsto

be

sep

arat

edar

eh

eat-

sen

siti

ve

(e.g

.,an

tib

ioti

cs)

or

rela

tivel

yn

onvo

lati

le(e

.g.,

min

eral

salt

s).

Liq

uid

–li

qu

idex

trac

tio

nis

use

din

ind

ust

ryfo

rth

efo

llow

ing

pu

rpo

ses:

1)

Sep

arat

ion

of

syst

ems

wit

hsi

mil

arb

oil

ing

po

ints

(e.g

.,se

par

atio

no

far

om

atic

sfr

om

alip

hat

ichydro

carb

ons)

;2

)se

par

atio

no

fh

igh

bo

iler

san

dlo

wco

nce

n-

trat

edso

lute

sfr

om

aqu

eou

sso

luti

on

s(e

.g.,

ph

eno

l);

3)

sep

arat

ion

of

mix

ture

sw

ith

hig

hb

oil

ing

po

ints

(e.g

.,v

itam

ins)

;4

)se

par

atio

no

fte

mp

erat

ure

-sen

siti

ve

com

-p

ou

nd

s(e

.g.,

acry

late

s,b

iote

chn

olo

gy

);5

)se

par

atio

no

faz

eotr

op

icm

ixtu

res

(ex

trac

-ti

on

of

acet

ico

rfo

rmic

acid

fro

maq

ueo

us

med

iau

sin

g,

e.g

.,M

TB

Eas

solv

ent)

;6

)ex

trac

tion

of

org

anic

com

pounds

from

salt

solu

tio

ns

(e.g

.,ca

pro

lact

am);

7)

extr

acti

on

of

salt

sfr

om

po

lym

erso

luti

on

s(e

.g.,

ket

on

ere

sin

s,p

oly

ols

);8

)ex

trac

tio

no

fm

etal

salt

sfr

om

low

-gra

de

ore

s(e

.g.,

cop

per

);9

)ex

trac

tio

no

fm

etal

salt

sfr

om

was

tew

ater

(e.g

.,co

pp

er);

10

)re

cover

yo

fn

ucl

ear

fuel

s(P

ure

xp

roce

ss).

Fig

ure

1.

Pri

nci

ple

sof

extr

acti

on

–st

ream

s,phas

esan

dco

mponen

ts

Pro

cess

esap

pli

edin

the

pet

role

um

ind

ust

ry,

inm

etal

-sal

tex

trac

tio

nan

din

chem

ical

and

bio

-ch

emic

alp

roce

sses

are

des

crib

edin

Ch

apte

r5

.

4Liq

uid

–Liq

uid

Extr

action

On

lya

gen

eral

ou

tlin

eis

giv

enin

this

arti

-cl

e.F

or

furt

her

det

ails

,th

ere

ader

isre

ferr

edto

bo

ok

s[1

–7

]an

dth

eP

roce

edin

gs

of

the

Inte

r-n

atio

nal

So

lven

tE

xtr

acti

on

Co

nfe

ren

ce(I

SE

C)

[8–

17

].D

ata

of

liq

uid

–li

qu

ideq

uil

ibri

aca

nb

efo

un

din

[18

],[1

9]

and

[20

].

Fig

ure

2.

Tri

angula

rd

iag

ram

for

rep

rese

nta

tio

no

fa

thre

e-co

mponen

tsy

stem

2.

Th

erm

od

yn

am

icF

un

dam

enta

ls

Aco

mp

reh

ensi

ve

trea

tmen

to

fth

eth

erm

od

y-

nam

icfu

nd

amen

tals

of

ph

ase

equ

ilib

ria

isg

iven

else

wh

ere

(→A

bso

rpti

on

;→

Dis

till

atio

nan

dR

ecti

fica

tio

n).

2.1

.G

rap

hic

Rep

rese

nta

tio

no

fP

ha

se

Eq

uil

ibri

a

2.1

.1.

Tri

an

gu

lar

Dia

gra

ms

Tri

ang

ula

rd

iag

ram

s(F

ig.2

)ar

eu

sed

for

rep

re-

sen

tin

gth

ree-

com

po

nen

tsy

stem

s.E

ver

yp

oss

i-b

leco

mp

osi

tio

no

fth

ete

rnar

ym

ixtu

reco

rre-

spo

nd

sto

ap

oin

tin

the

dia

gra

m.

Eac

hco

rner

of

the

tria

ng

lere

pre

sen

tsa

pu

reco

mp

on

ent

and

its

des

ign

atio

nis

mar

ked

atth

isco

rner

.O

nth

esi

de

op

po

site

toth

isco

rner

the

mas

sfr

acti

on

of

this

com

po

nen

tis

zero

.T

he

sid

eso

fth

etr

ian

-g

lere

pre

sen

tth

eco

rres

po

nd

ing

two

-co

mp

on

ent

syst

ems.

Th

ep

rop

ort

ion

so

fth

ein

div

idu

alco

m-

po

nen

tsin

am

ixtu

rear

eo

bta

ined

asfo

llow

s:T

he

mas

sfr

acti

on

of

each

com

po

nen

tis

giv

enb

yli

nes

par

alle

lto

the

sid

eo

pp

osi

teto

the

cor-

ner

wh

ich

rep

rese

nts

the

pu

reco

mp

on

ent,

fro

m0

kg

/kg

atth

iso

pp

osi

tesi

de

to1

kg

/kg

atth

eco

r-n

er.

Th

en

um

ber

ing

can

be

pla

ced

atth

eed

ges

of

the

tria

ng

le,

inw

hic

hca

seit

isad

vis

able

toex

ten

dth

eli

nes

.T

he

nu

mb

ers

can

also

be

in-

sert

edin

the

mid

dle

of

the

lin

es.T

his

mak

esth

ed

iag

ram

easi

erto

use

bu

tso

me

of

the

nu

mb

ers

are

alw

ays

skew

and

inver

ted

.T

he

po

int

Ph

asth

eco

mp

osi

tio

n0

.5k

g/k

gC

,0

.2k

g/k

gA

,an

d0

.3k

g/k

gB

.T

he

foll

ow

ing

rule

sap

ply

inth

etr

ian

gu

lar

di-

agra

m:

Ifco

mp

on

ent

Cis

add

edto

am

ixtu

reo

f0

.8k

g/k

gA

and

0.2

kg

/kg

B,re

pre

sen

ted

by

the

po

int

D,

then

the

com

po

siti

on

of

the

new

mix

-tu

refo

llow

sth

ep

ath

of

the

stra

igh

tli

ne

DC

.O

nth

isst

raig

ht

lin

e,an

do

nal

lst

raig

ht

lin

esw

hic

hp

ass

thro

ug

ha

corn

er,th

era

tio

bet

wee

nth

etw

oo

ther

com

po

nen

tsw

hic

hd

on

ot

form

the

corn

eris

con

stan

t.If

am

ixtu

reo

fco

mp

osi

tio

nU

and

on

eo

fco

mp

osi

tio

nV

are

com

bin

edth

enth

ere

sult

ing

mix

ture

lies

on

the

stra

igh

tco

nn

ecti

ng

lin

eU

V.

Th

eco

mp

osi

tio

no

fth

efi

nal

mix

ture

iso

bta

ined

by

div

idin

gth

eco

nn

ecti

ng

lin

eb

etw

een

the

two

ori

gin

alm

ixtu

res

inin

ver

sera

tio

toth

eq

uan

titi

esm

ixed

(lev

erru

le).

Th

em

ixtu

reM

,fo

rex

amp

le,

com

pri

ses

thre

ep

arts

Uan

do

ne

par

tV

,an

dth

em

ixtu

reG

com

pri

ses

thre

ep

arts

Can

dtw

op

arts

D.T

he

con

cen

trat

ion

dat

ao

bta

ined

fro

mth

etr

ian

gu

lar

dia

gra

m(e

.g.,

po

int

G:

0.6

kg

/kg

C,

0.0

8k

g/k

gB

,0

.32

kg

/kg

A;

B:

A=

1:

4)

app

lyto

the

tota

lquan

tity

of

resu

ltin

gm

ixtu

rere

gar

d-

less

of

wh

eth

erit

ish

om

og

eneo

us

or

sep

arat

edin

tose

ver

alp

has

es.

As

ever

yp

oin

tin

atr

ian

gu

lar

dia

gra

mco

rre-

spo

nd

sto

aco

mp

osi

tio

nth

ere

isn

oco

ord

inat

efr

eefo

ran

oth

erre

fere

nce

var

iab

le.I

tis

on

lyp

os-

sib

leto

plo

tp

aram

eter

ssu

chas

lin

eso

feq

ual

den

sity

,boil

ing

poin

tsor

oth

erphysi

cal

dat

a,li

nes

of

equ

alac

tiv

ity

coef

fici

ents

or

lin

eso

fp

has

eb

ou

nd

arie

s.O

nly

tern

ary

syst

ems

wit

hm

isci

bil

ity

gap

sar

esu

itab

lefo

rex

trac

tio

ns,

and

the

bo

un

dar

yli

ne

bet

wee

nth

eli

qu

idsi

ng

le-p

has

ere

gio

n(s

)an

dth

etw

o-p

has

ere

gio

nis

par

ticu

larl

yim

po

r-ta

nt.

Th

isb

ou

nd

ary

lin

eis

call

edth

eb

ino

da

l

curv

e(F

ig.3

).E

ver

yp

oin

to

nth

eb

ino

dal

curv

e(e

xce

pt

the

pla

itp

oin

tin

syst

ems

wit

ha

com

-p

lete

bin

od

alcu

rve,

see

bel

ow

)is

ineq

uil

ibri

um

wit

han

oth

erb

ino

dal

po

int.

Th

eli

nes

wh

ich

con

-n

ect

po

ints

ineq

uil

ibri

um

wit

ho

ne

ano

ther

are

call

edti

eli

nes

.A

llm

ixtu

res

wh

ich

corr

esp

on

dto

ap

oin

ton

the

tie

lin

ese

par

ate

into

two

ph

ases

.T

he

com

po

siti

on

of

thes

ep

has

esis

giv

enb

yth

e

Page 3: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

5

Fig

ure

3.

Defi

nit

ions

of

phas

eeq

uil

ibri

aan

dm

ass

frac

tions

ina

tria

ngula

rdia

gra

mA

)P

has

eeq

uil

ibri

a;B

)M

ass

frac

tions

end

po

ints

of

the

tie

lin

esan

dth

eir

qu

anti

ties

are

giv

enb

yth

ele

ver

rule

.T

he

equ

ilib

riu

md

ata

hav

eto

be

det

erm

ined

exp

erim

enta

lly

inea

chin

-d

ivid

ual

case

.L

ines

par

alle

lto

the

tria

ng

lesi

des

CB

and

AC

resp

ecti

vel

y,d

raw

nth

rou

gh

rela

ted

po

ints

of

equ

ilib

riu

mo

nb

oth

bra

nch

eso

fth

eb

ino

dal

curv

e,p

rod

uce

anau

xil

iary

lin

e,fo

rmed

by

the

inte

rsec

tio

ns

of

the

par

alle

ls,

and

enab

leto

con

stru

ctan

yti

eli

ne

asd

emo

nst

rate

din

Fig

-u

re3

A.

Sev

eral

typ

eso

ftr

ian

gu

lar

dia

gra

ms

are

show

nin

Fig

ure

4.

Inev

ery

syst

emw

ith

aco

m-

ple

teb

ino

dal

curv

e(c

lose

dd

iag

ram

,T

yp

eII

inF

ig.4

)th

een

dp

oin

tso

fth

eti

eli

nes

dra

wcl

ose

ran

dcl

ose

rto

get

her

un

til

they

fin

ally

coin

cid

eat

the

pla

itp

oin

t.T

he

pla

itp

oin

to

nth

eb

ino

dal

curv

ere

pre

sen

tsa

sin

gle

ph

ase

wh

ich

do

esn

ot

spli

tin

totw

op

has

es.

Dia

gra

mI

isca

lled

ano

pen

dia

gra

min

wh

ich

Bis

no

tfu

lly

mis

cib

lew

ith

the

sub

stan

ceto

be

dis

solv

ed.T

he

cap

acit

yo

fsu

cha

solv

ent

isco

r-re

spo

nd

ing

lylo

wan

dit

sse

lect

ivit

yis

usu

ally

hig

h(s

eeS

ecti

on

2.4

).

Ind

iag

ram

IIth

esu

bst

ance

tob

eex

trac

ted

(C)

isto

tall

ym

isci

ble

wit

hb

oth

Aan

dB

.T

his

form

of

extr

acti

on

dia

gra

mis

oft

enfo

un

din

ex-

trac

tio

ns

wh

ere

solu

teC

and

Aar

ep

rese

ntin

ap-

pro

xim

atel

yth

esa

me

qu

anti

ties

.If

inth

isca

seth

eco

nce

ntr

atio

no

fC

inth

eA

B-m

ixtu

reis

too

hig

h(h

igh

erth

anth

eco

nce

ntr

atio

nat

the

pla

itp

oin

t)th

esy

stem

form

so

nly

on

ep

has

ean

dex

-tr

acti

on

isn

ot

po

ssib

le.

Dia

gra

mII

Ish

ow

sa

syst

emw

her

eC

has

am

isci

bil

ity

gap

wit

hA

.It

sco

nce

ntr

atio

nin

the

B-r

ich

ph

ase

isth

ensu

bst

anti

ally

hig

her

than

inth

efe

ed.

Th

ed

iag

ram

isty

pic

alfo

rw

aste

wat

erex

trac

tio

ns.

Dia

gra

mIV

isan

op

entr

ian

gu

lar

dia

gra

min

wh

ich

thre

eli

qu

idp

has

esar

efo

rmed

inth

em

id-

dle

con

cen

trat

ion

ran

ge.

Th

isb

ehav

ior

iso

ften

found

insy

stem

sco

nsi

stin

gof

inorg

anic

salt

sin

aqueo

us

solu

tions

and

org

anic

solv

ents

.T

he

app

eara

nce

ofa

thir

dli

qu

idp

has

eca

nca

use

con

-si

der

able

dif

ficu

ltie

sd

uri

ng

met

al-s

alt

extr

ac-

tio

n(s

eeS

ecti

on

5.3

).T

he

infl

uen

ceo

fp

ress

ure

on

the

bin

od

alcu

rve

and

equ

ilib

ria

isn

egli

gi-

ble

bel

ow

val

ues

of

sever

alb

ar.T

he

infl

uen

ceo

f

6Liq

uid

–Liq

uid

Extr

action

tem

per

atu

reis

stro

ng

.Th

elo

wer

the

tem

per

atu

reth

em

ore

wil

lth

etr

ian

gu

lar

dia

gra

mn

orm

ally

be

fill

edby

the

mis

cibil

ity

gap

.

Fig

ure

4.

Var

ious

typ

eso

fp

has

eeq

uil

ibri

ain

tern

ary

sys-

tem

sT

ype

I:O

pen

syst

em,m

isci

bil

ity

gap

bet

wee

nth

ekey

com

-ponen

tof

the

solv

ent

(B)

and

solu

teC

Type

II:

Clo

sed

syst

em,

Cis

com

ple

tely

mis

cib

lew

ith

the

key

com

ponen

tof

the

feed

(A)

and

the

key

com

po

nen

to

fth

eex

trac

tion

solv

ent

(B)

Type

III:

Open

syst

em,m

isci

bil

ity

gap

bet

wee

nA

and

CT

ype

IV:

Syst

emw

ith

form

atio

no

fth

ree

ph

ases

2.1

.2.

Oth

erG

rap

hic

Rep

rese

nta

tio

ns

Liq

uid

two

-ph

ase

syst

ems

com

pri

sin

gth

ree

com

po

nen

tsca

nal

sob

ep

lott

edo

nre

ctan

gu

lar

coo

rdin

ates

.In

man

yca

ses

thes

ed

iag

ram

sar

ep

refe

rred

bec

ause

the

mea

sure

dval

ues

can

be

adju

sted

bet

ter

and

the

con

fig

ura

tio

no

fth

eca

l-cu

lati

on

sis

sim

ple

r.T

he

mo

stim

po

rtan

tfo

rms

of

rep

rese

nta

tio

nar

esh

ow

nfo

rth

ree

mix

ture

sin

Fig

ure

s5

,6

,7

.A

com

pre

hen

sive

rev

iew

of

form

so

fre

pre

sen

tati

on

isg

iven

in[2

7].

Inth

eeq

uil

ibri

um

dia

gra

m(F

igs.

5,

6,

7II

)th

em

ass

frac

tio

no

fC

inth

eB

-ric

hp

has

eyC

(ord

inat

e)is

plo

tted

asa

fun

ctio

no

fth

ism

ass

frac

tio

nin

the

A-r

ich

ph

ase

xC

(ab

scis

sa).

Th

isd

iag

ram

isan

alo

go

us

toth

eM

cCab

e–

Th

iele

di-

agra

min

dis

till

atio

n(→

Dis

till

atio

nan

dR

ecti

-fi

cati

on

,C

hap

.4

.1.1

.).It

show

sth

ere

lati

on

ship

bet

wee

neq

uil

ibri

um

and

op

erat

ing

con

dit

ion

s.F

igu

re5

.Rep

rese

nta

tio

no

fp

has

ere

lati

on

ship

ofth

ete

rnar

ysy

stem

hep

tan

e(A

),d

ieth

yle

ne

gly

col

(B),

ben

zen

e(C

),at

20◦

C.

All

dat

are

fers

tom

ass

frac

tio

ns.

I)T

rian

gula

rd

iag

ram

;II

)E

qu

ilib

riu

md

iag

ram

;II

I)D

istr

i-bu

tio

nd

iag

ram

;IV

)S

elec

tiv

ity

dia

gra

m

Page 4: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

7

Fig

ure

6.R

epre

senta

tion

ofphas

ere

lati

onsh

ipofth

ete

rnar

ysy

stem

tric

hlo

roet

hyle

ne

(A),

wat

er(B

),ca

pro

lact

am(C

),at

20◦

C.A

lldat

are

fers

tom

ass

frac

tions.

I)T

rian

gula

rdia

gra

m;

II)

Equil

ibri

um

dia

gra

m;

III)

Dis

tri-

buti

on

dia

gra

m;

IV)

Sel

ecti

vit

ydia

gra

m

Inth

eex

amp

lesh

ow

nin

Fig

ure

s5

,6,7

III

the

dis

trib

uti

on

rati

os

of

the

extr

acte

dco

mp

on

ents

(ben

zen

e,ca

pro

lact

amo

rp

hen

ol)

are

plo

tted

asfu

nct

ion

so

fth

eir

mas

sfr

acti

on

sin

the

A-r

ich

ph

ase

(cu

rve

a)an

din

the

B-r

ich

ph

ase

(cu

rve

b).

Th

ed

istr

ibu

tio

nra

tio

kin

dic

ates

how

mu

chb

ette

ro

rw

ors

eth

eex

trac

ted

com

po

nen

tis

sol-

ub

lein

the

B-r

ich

than

inth

eA

-ric

hp

has

e;th

em

inim

also

lven

tra

tio

can

be

eval

uat

edd

irec

tly

fro

mF

igu

res

5,

6,

7II

I.T

he

dis

trib

uti

on

rati

oth

eref

ore

isan

imp

ort

ant

crit

erio

nfo

rth

ese

lec-

tio

no

fa

solv

ent.

Th

em

ass

frac

tio

nin

the

A-r

ich

ph

ase

isea

sier

tov

isu

aliz

eas

are

fere

nce

var

i-ab

le.

At

the

feed

stag

eit

corr

esp

on

ds

app

rox

i-m

atel

yto

the

init

ial

feed

con

cen

trat

ion

.It

gov

-er

ns

the

yie

ldat

the

raffi

nat

eo

utl

et.O

nth

eo

ther

han

d,s

how

ing

kas

afu

nct

ion

of

yC

(cu

rve

b)

has

the

advan

tag

eth

atit

per

mit

sco

mp

aris

on

sw

ith

resp

ectto

solv

entlo

adin

g.I

tis

alw

ays

adv

isab

leto

plo

tb

oth

curv

esb

ecau

seth

eir

suit

abil

ity

for

extr

apo

lati

on

and

inte

rpo

lati

on

var

ies

con

sid

er-

ably

inth

ed

iffe

ren

tco

nce

ntr

atio

nra

ng

es.

Inth

ese

lect

ivit

yd

iag

ram

(Fig

s.5

,6,7

IV)th

eq

uo

tien

to

ftw

od

istr

ibu

tio

nra

tio

sis

plo

tted

asa

fun

ctio

no

fth

em

ass

frac

tio

ns

of

com

po

nen

tC

inth

eA

-ric

h(c

urv

ea)

and

inth

eB

-ric

hp

has

e(c

urv

eb

).T

he

qu

oti

ent

of

the

dis

trib

uti

on

rati

os

for

the

extr

acte

dco

mp

on

ent

C(y

C/x

C)

and

for

A(y

A/x

A)

corr

esp

on

ds

toth

ere

lati

ve

vo

lati

lity

ind

isti

llat

ion

(see

Sec

tio

n5

.1).

Itis

am

easu

reo

fth

ese

lect

ivit

yo

fa

solv

ent.

2.2

.M

easu

rin

gM

eth

od

so

fP

ha

se

Eq

uil

ibri

a

Wh

enev

erp

oss

ible

ate

rnar

ysy

stem

isu

sed

asth

est

arti

ng

po

int

for

mea

sure

men

to

fli

q-

uid

–li

qu

ideq

uil

ibri

a.It

isfi

rst

nec

essa

ryto

es-

tab

lish

wh

ich

of

the

thre

ep

oss

ible

bin

ary

sys-

tem

shav

ea

mis

cibil

ity

gap

and

whic

har

eco

m-

ple

tely

mis

cib

le.F

or

this

pu

rpo

seit

issu

ffici

ent

inea

chca

seto

mix

the

two

sub

stan

ces

inra

-ti

os

of

3:

1,

1:

1an

d1

:3

.If

no

form

atio

no

ftw

oli

qu

idp

has

eso

ccu

rsin

any

of

the

case

sth

enth

esy

stem

isfu

lly

mis

cib

lean

dn

ot

suit

able

for

extr

acti

on

.

8Liq

uid

–Liq

uid

Extr

action

Fig

ure

7.R

epre

senta

tio

no

fp

has

ere

lati

on

ship

ofth

ete

rnar

ysy

stem

wat

er(A

),bu

tyl

acet

ate

(B),

ph

eno

l(C

),at

20◦

C.

All

dat

are

fers

tom

ass

frac

tio

ns.

I)T

rian

gula

rdia

gra

m;

II)

Eq

uil

ibri

um

dia

gra

m;

III)

Dis

tri-

buti

on

dia

gra

m;

IV)

Sel

ecti

vit

yd

iag

ram

If,

for

exam

ple

,A

and

Bar

en

ot

mis

cib

lew

hil

eth

eth

ird

,C

,is

com

ple

tely

mis

cib

lew

ith

the

two

oth

ers

(clo

sed

tria

ng

ula

rd

iag

ram

)th

enth

eb

ino

dal

curv

eca

nb

ed

eter

min

edas

fol-

low

s.E

qu

alam

ou

nts

of

Aan

dB

are

pla

ced

ina

con

tro

lled

-tem

per

atu

reves

sel

wh

ich

can

be

shak

en(e

.g.,

anE

rlen

mey

erfl

ask

ina

ther

mo

-st

at)

and

sub

stan

ceC

isad

ded

un

til

the

mix

ture

bec

om

escl

ear.

Intw

ofu

rth

erex

per

imen

tsp

ure

Ao

rB

isp

lace

din

the

ves

sel

and

inea

chca

seth

ese

con

dsu

bst

ance

isth

enad

ded

un

til

turb

id-

ity

occ

urs

.Th

ree

po

ints

hav

en

ow

bee

no

bta

ined

inth

etr

ian

gu

lar

dia

gra

man

dth

eap

pro

xim

ate

shap

eo

fth

eb

ino

dal

curv

eis

kn

ow

n.

Fo

rp

reci

sed

eter

min

atio

no

fth

eb

ino

dal

curv

e,m

ixtu

res

of

Aan

dC

con

tain

ing

0.9

,0

.8,

0.7

(etc

.,fo

ras

far

asap

pea

rsn

eces

sary

)k

g/k

gA

are

pre

par

edan

dti

trat

edw

ith

Bat

con

stan

tte

mp

erat

ure

.W

hen

turb

idit

yis

reac

hed

titr

atio

nis

ceas

edan

da

smal

lq

uan

tity

of

the

ori

gin

alA

Cm

ixtu

reis

added

unti

lth

eso

luti

on

iscl

ear

agai

n.

Th

ena

char

acte

rist

icvar

iab

lesu

chas

refr

ac-

tive

ind

ex,

den

sity

,d

iele

ctri

cco

nst

ant,

free

zin

gp

oin

t,b

oil

ing

po

int,

etc.

of

this

mix

ture

can

be

det

erm

ined

.In

the

sam

ew

aym

ixtu

res

of

Can

dB

are

titr

ated

wit

hA

.T

his

mea

sure

men

tg

ives

the

pre

cise

shap

eo

fth

eb

ino

dal

curv

ean

dal

lth

eco

mp

osi

tio

ns

lyin

go

nth

iscu

rve

can

be

defi

ned

by

ap

hysi

cal

par

amet

er.

To

det

erm

ine

ph

ase

equ

ilib

riu

man

dth

ere-

wit

hth

eti

eli

nes

,i.

e.,

the

po

ints

wh

ich

are

ineq

uil

ibri

um

wit

ho

ne

ano

ther

,am

ixtu

refr

om

the

two

-ph

ase

reg

ion

isp

lace

din

aco

ntr

oll

ed-t

em-

per

atu

re,s

hak

ing

cyli

nd

er.E

qu

ilib

riu

mis

esta

b-

lish

edb

ysh

akin

g.T

he

ph

ases

are

allo

wed

tose

t-tl

ean

dar

ese

par

ated

by

dra

inin

go

ffin

tod

iffe

r-en

tves

sels

.Th

enth

eir

qu

anti

ties

are

det

erm

ined

and

the

physi

calv

aria

ble

mea

sure

dduri

ng

det

er-

min

atio

no

fth

eb

ino

dal

curv

eis

then

mea

sure

dfo

rb

oth

ph

ases

.T

his

imm

edia

tely

giv

esth

etw

oti

eli

ne

po

ints

.Fu

rth

erm

ore

,bo

thp

has

esca

nal

sob

ean

aly

zed

by

wel

lk

now

nch

emic

alm

eth

od

s,su

chas

gas

or

liquid

chro

mat

ogra

phy

and

titr

a-ti

on

.Th

eco

rrec

tnes

so

fth

em

easu

rem

entca

nb

ech

ecked

by

con

nec

tin

gth

etw

oti

eli

ne

po

ints

inth

etr

ian

gu

lar

dia

gra

m.

Th

eco

nn

ecti

ng

lin

em

ust

pas

sth

rou

gh

the

po

int

of

the

ori

gin

alm

ix-

ture

,an

dth

isp

oin

tm

ust

div

ide

the

len

gth

of

the

tie

lin

ein

inver

sera

tio

toth

eq

uan

titi

eso

fth

etw

op

has

es.

Page 5: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

9

Ifa

syst

emo

fm

ore

than

thre

eco

mp

on

ents

has

tob

em

easu

red

then

sever

alco

mp

on

ents

are

com

bin

edin

too

ne

gro

up

ino

rder

toar

rive

ata

tern

ary

syst

emag

ain.D

eter

min

atio

nofa

bin

odal

curv

ew

ou

ldst

ill

be

po

ssib

lein

such

aca

sebu

tth

etw

op

has

esin

tow

hic

hth

ete

stm

ixtu

rese

p-

arat

esar

en

olo

ng

erid

enti

cal

wit

hth

em

ixtu

res

wh

ich

wer

eo

bta

ined

du

rin

gth

ed

eter

min

atio

no

fth

eb

ino

dal

curv

e.It

isth

eref

ore

bet

ter

toal

low

the

mix

ture

tore

ach

equ

ilib

riu

mco

nd

itio

ns

ina

con

tro

lled

-tem

per

atu

re,

shak

ing

cyli

nd

er,

sep

a-ra

teit

and

then

anal

yze

the

ph

ases

usi

ng

som

ep

rep

lan

ned

met

ho

d.

Th

eti

me

con

sum

ing

step

inth

ed

eter

min

atio

no

feq

uil

ibri

ais

the

pre

par

atio

no

fth

eex

per

imen

t,su

chas

pu

rifi

cati

on

of

the

sub

stan

ces,

sett

ing

up

the

cali

bra

tio

ncu

rves

,et

c.T

her

efo

reit

isse

nse

-le

ssto

rest

rict

the

nu

mb

ero

fm

easu

red

po

ints

and

use

inte

rpo

lati

on

met

ho

ds.

To

incr

ease

the

accu

racy

am

ater

ial

bal

ance

isse

tu

pfo

rea

chco

mp

on

enta

nd

the

mea

sure

dp

oin

tsar

ead

just

edb

yd

raw

ing

the

curv

esfr

om

Fig

ure

s5

,6

,7

.

2.3

.E

mp

iric

al

Co

rrel

ati

on

so

fP

ha

se

Eq

uil

ibri

a

Inte

rnar

ysy

stem

s,th

eu

seo

fem

pir

ical

corr

e-la

tio

ns

tore

pre

sen

tth

eb

ino

dal

curv

esan

dd

is-

trib

uti

on

equ

ilib

ria

of

com

po

nen

tC

iso

fad

van

-ta

ge

[28

].T

he

mu

tual

solu

bil

itie

so

fth

eli

qu

idp

has

esar

eu

sual

lyd

eter

min

edb

ya

lab

ora

tory

turb

idit

yti

trat

ion

.T

he

bin

od

alcu

rve

isth

end

e-te

rmin

edb

yex

trap

ola

tin

gth

em

easu

red

val

ues

(see

Sec

tio

n2

.2).

InT

yp

eI

syst

ems

wit

han

op

enm

isci

bil

ity

gap

,th

ebin

odal

curv

eca

nbe

sim

ply

des

crib

edb

yp

arab

oli

ceq

uat

ion

s:

x=

D′+

E′x′ A

+F′x′2 A

y=

D′′+

E′′x′′ B+

F′′x′′2

B

wh

ere

x′ A

isth

em

ass

frac

tio

no

fA

inth

eA

-ric

hp

has

e,x′′ B

the

mas

sfr

acti

on

of

Bin

the

B-r

ich

ph

ase

and

D′,D′′,E′,E′′,F′

and

F′′

are

coef

-fi

cien

ts.

Insy

stem

sw

ith

acl

ose

dm

isci

bil

ity

gap

(Ty

pe

II),

the

par

abo

lic

equ

atio

ns

are

on

lyval

idfo

rth

elo

wer

par

tso

fth

ecu

rve;

they

can

no

tb

eu

sed

tore

pre

sen

tth

een

tire

bin

od

alcu

rve.

Th

eb

esteq

uat

ion

for

the

clo

sed

bin

od

alcu

rve

isth

atp

rop

ose

db

yH

lavaty

[29

].T

he

corr

elat

ion

is

der

ived

fro

ma

po

lyn

om

ial

equ

atio

nan

dh

asth

ead

van

tag

eth

atth

eb

ino

dal

curv

een

ds

exac

tly

atth

eb

inar

yso

lub

ilit

yp

oin

ts.

Its

dis

advan

tag

eis

,h

ow

ever

,th

atth

elo

wer

,in

pra

ctic

ev

irtu

ally

lin

-ea

r,re

gio

ns

ofth

eb

ino

dal

curv

esar

ere

pre

sen

ted

inw

ave

form

asa

resu

lto

fth

ep

oly

no

mia

leq

ua-

tio

n.T

he

Hla

vat

yeq

uat

ion

sho

uld

,th

eref

ore

,b

eu

sed

wit

hca

uti

on

.T

he

equ

ilib

riu

md

istr

ibu

tio

no

fso

lute

Cin

the

A-an

dB

-ric

hp

has

esis

gen

eral

lyd

eter

min

edin

dep

end

entl

yfr

om

the

bin

od

alcu

rve

by

mea

ns

of

lab

ora

tory

exp

erim

ents

.Th

em

ass

frac

tio

nxC

and

yC

ofth

etw

op

has

esin

ther

mo

dy

nam

iceq

ui-

lib

riu

mar

eth

us

ob

tain

edan

dd

eter

min

eth

ep

o-

siti

on

so

fth

een

dp

oin

tso

fth

eti

eli

nes

on

the

bin

od

alcu

rves

(see

Sec

tio

n2

.2).

Eq

uat

ion

sfo

rco

rrel

atin

gan

din

terp

ola

tin

gth

een

dp

oin

to

fth

eti

eli

nes

are

des

crib

edin

the

lite

ratu

re,

they

are

pri

mar

ily

exp

on

enti

aleq

uat

ion

ssu

chas

tho

sep

rop

ose

db

yO

th

mer

and

Tobia

s,

and

Han

d

[1].

How

ever

,al

lex

po

nen

tial

equ

atio

ns

gen

er-

ally

fail

wh

enth

eco

nce

ntr

atio

no

fC

isver

ylo

w.

To

allo

wa

mo

reac

cura

tees

tim

atio

no

fd

istr

i-bu

tio

neq

uil

ibri

aan

dex

trac

tio

np

roce

sses

atth

elo

wra

ffin

ate

con

cen

trat

ion

sth

atar

eo

fin

du

stri

alim

po

rtan

ce,B

en

der

and

Block

[28

]p

rop

ose

dth

efo

llow

ing

corr

elat

ion

for

the

dis

trib

uti

on

ra-

tio

K:

K=

G1+

G2x′ C

+G

3x′2 C+

G4x′3 C

Th

eco

effi

cien

tsG

im

ust

be

fitt

edto

the

mea

-su

red

val

ues

of

the

tie

lin

esx

and

y.

Alt

ho

ug

hth

eeq

uat

ion

do

esn

ot

gen

eral

lyp

erm

itex

trap

o-

lati

on

of

the

curv

eab

ove

the

mea

sure

dval

ues

toth

ep

lait

po

int,

the

dis

trib

uti

on

coef

fici

entK

can

be

ob

tain

edac

cura

tely

up

tox

and

y→

0.

Th

eem

pir

ical

corr

elat

ion

sar

esi

mp

lean

dcl

ear.

Th

eyca

nb

eca

lcu

late

dq

uic

kly

wit

hap

-p

rop

riat

eco

mp

ute

rp

rog

ram

san

dg

ive

anac

cu-

rate

rep

rese

nta

tio

no

fth

em

easu

red

liq

uid

–li

q-

uid

equ

ilib

ria.

How

ever

,th

ese

advan

tag

esar

eac

-co

mp

anie

db

yse

ver

ald

isad

van

tag

es.T

he

corr

e-la

tio

ns

can

on

lyb

eu

sed

wit

hte

rnar

ysy

stem

san

dd

on

ot

allo

wex

trap

ola

tio

nto

hig

her

mu

lti-

com

po

nen

tsy

stem

s.E

xte

nsi

ve

lab

ora

tory

wo

rkis

req

uir

edto

det

erm

ine

the

mu

tual

solu

bil

itie

so

fco

mp

on

ents

Aan

dB

asa

fun

ctio

no

fth

eco

nce

ntr

atio

no

fC

asw

ell

asth

eeq

uil

ibri

um

dis

trib

uti

on

of

com

po

nen

tC

.S

yst

emat

icm

ea-

sure

men

ter

rors

can

no

tb

ed

etec

ted

bec

ause

the

exp

erim

enta

lval

ues

are

emp

iric

ally

corr

elat

ed.

10

Liq

uid

–Liq

uid

Extr

action

2.4

.S

elec

tio

no

fS

olv

ent

Th

ese

lect

ion

of

the

mo

stsu

itab

leso

lven

tis

on

eo

fth

eh

ard

est

pro

ble

ms

of

the

extr

acti

on

,an

dth

ed

ecis

ion

mad

eh

asa

gre

atin

flu

ence

on

the

eco

no

my

of

the

pro

cess

.Th

eso

lven

tm

ust

fulfi

lltw

ob

asic

req

uir

emen

ts:

1)

itm

ust

hav

ea

mis

cibil

ity

gap

wit

hth

eA

-ric

hp

has

e,an

d2

)it

mu

stb

ea

bet

ter

solv

ent

for

com

po

nen

tC

than

for

A.

Ag

reat

nu

mb

ero

fm

eth

od

sh

ave

bee

nre

com

-m

end

edfo

rd

isco

ver

ing

suit

able

solv

ents

[30

],[3

1].

Th

em

ore

emp

iric

alst

rate

gy

of

form

erti

mes

isb

ein

gre

pla

ced

mo

rean

dm

ore

by

asy

s-te

mat

icre

sear

chw

ith

the

aid

of

dat

ab

ank

s[2

6].

Th

eco

nce

pt

of

po

lari

tyis

use

dfo

rch

arac

teri

z-in

gsu

itab

lep

aram

eter

s[3

2].

Th

eg

reat

erth

ed

iffe

ren

cein

po

lari

tyb

etw

een

two

liq

uid

s,th

eg

reat

eris

the

pro

bab

ilit

yth

atth

eyh

ave

am

isci

bil

ity

gap

.T

he

subst

ance

tobe

extr

acte

dw

illh

ave

ah

igh

erco

nce

ntr

atio

nin

the

liq

uid

tow

hic

hit

iscl

ose

rin

po

lari

ty.

How

ever

,th

ere

lati

on

ship

sar

en

ot

sosi

mp

leth

ato

nly

asc

ale

of

po

lari

ties

has

tob

ese

tu

pan

dth

ed

iffe

ren

cein

po

lari

tyat

wh

ich

mis

ci-

bil

ity

gap

socc

ur

read

off

the

scal

e.F

or

exam

-p

le,

anil

ine,

ph

eno

l,an

dfu

rfu

ral

hav

em

isci

bil

-it

ygap

sw

ith

both

wat

eran

dhex

ane.

Ace

tone,

eth

ano

l,an

dd

iox

anw

hic

hh

ave

asi

mil

arp

ola

r-it

yar

em

isci

ble

wit

hb

oth

wat

eran

dh

exan

e.T

he

mo

lecu

lar

form

and

the

size

of

the

mo

lecu

leal

soco

ntr

ibu

teto

solv

ent

beh

avio

r.T

he

beh

avio

ro

fso

lven

tsto

war

ds

hydro

carb

ons

has

bee

nin

ves

-ti

gat

edpar

ticu

larl

yin

tensi

vel

y[3

3],

[34].

Itis

also

po

ssib

leto

ob

tain

effe

cts

fro

mm

ixin

gtw

oso

lven

tsw

hic

hco

uld

no

tb

ep

red

icte

dfr

om

the

pro

per

ties

of

the

mix

com

po

nen

ts[3

5],

[36

].T

he

mo

stim

po

rtan

tp

rop

erty

of

aso

lven

tis

its

sele

ctiv

ity.

Th

isin

dic

ates

how

mu

chb

ette

rth

eso

lute

isd

isso

lved

than

the

A-r

ich

ph

ase.

As

can

be

seen

fro

mF

igu

res

5,6

,7

III

the

sele

ctiv

ity

isst

ron

gly

dep

end

ent

on

con

cen

trat

ion

.In

add

itio

nto

sele

ctiv

ity

the

cap

aci

tyo

fa

sol-

ven

tis

also

imp

ort

ant.

Th

isis

defi

ned

by

the

dis

trib

uti

on

coef

fici

ent

of

Cb

etw

een

the

B-r

ich

and

A-r

ich

ph

ases

and

det

erm

ines

the

qu

anti

tyo

fso

lven

tw

hic

hh

asto

be

recy

cled

.W

hen

test

ing

dif

fere

nt

solv

ents

for

asp

ecifi

cex

trac

tio

nta

skit

iso

ften

fou

nd

that

solv

ents

wit

hh

igh

erse

-le

ctiv

itie

sh

ave

low

erca

pac

itie

san

dv

ice

ver

sa.

Th

eg

reat

erth

eth

rou

gh

pu

to

fa

pla

nt

the

mo

reim

po

rtan

tth

eca

pac

ity

of

the

solv

ent

isfo

rth

eec

on

om

yo

fth

ep

roce

ss.I

fth

ere

are

sever

alp

os-

sib

leso

lven

tsfo

ra

pro

cess

then

thei

rb

ehav

ior

wit

hre

spec

tto

sele

ctiv

ity

and

cap

acit

yca

nb

ete

sted

wit

ha

gas

chro

mat

og

rap

hw

ith

ou

tst

art-

ing

wit

hti

me-

con

sum

ing

equ

ilib

riu

mm

easu

re-

men

ts[3

7].

Inad

dit

ion

toth

ese

bas

icre

qu

irem

ents

ther

ear

eal

soo

ther

crit

eria

wh

ich

mu

stb

eta

ken

into

con

sid

erat

ion

wh

ense

lect

ing

aso

lven

tan

dw

hic

hsh

arp

lyre

du

ceth

en

um

ber

of

po

ssib

leco

mp

ou

nd

s.M

ost

imp

ort

anti

sth

eav

aila

bil

ity

of

the

solv

ent

inco

mm

erci

alq

uan

titi

esat

anec

o-

no

mic

ally

acce

pta

ble

pri

ce.

Itis

then

nec

essa

ryto

fin

dd

ata

con

cern

ing

bo

ilin

gp

oin

ts,

den

sity

,v

isco

sity

and

–w

her

eav

aila

ble

–in

form

atio

nab

ou

tso

lub

ilit

y[3

8],

[39

].T

he

bo

ilin

gp

oin

to

fth

eso

lven

tis

imp

ort

ant

bec

ause

the

extr

acte

dco

mp

on

entis

usu

ally

sep

-ar

ated

fro

mth

eso

lven

tb

yd

isti

llat

ion

and

the

bo

ilin

gp

oin

td

iffe

ren

ced

eter

min

esth

ere

flu

xra

tio

inth

isd

isti

llat

ion

.If

the

solv

ent

bo

ils

ata

hig

her

tem

per

atu

reth

anth

eso

lute

,th

isso

lute

isd

isti

lled

over

hea

d.If

itis

nec

essa

ryto

recy

cle

ag

reat

dea

lo

fso

lven

tth

enth

eso

lven

th

asto

be

pu

rifi

edb

yd

isti

llat

ion

ina

sub

seq

uen

tst

ep;

the

spec

ific

hea

tw

hic

his

req

uir

edfo

rh

eati

ng

the

solv

ent

toit

sb

oil

ing

tem

per

atu

rem

ust

also

be

taken

into

acco

un

t.T

oo

gre

ata

tem

per

atu

red

iffe

ren

ceis

then

ad

isad

van

tag

e.T

he

den

sity

of

the

solv

enti

sim

po

rtan

tfo

ro

b-

tain

ing

asu

ffici

entl

yla

rge

dif

fere

nce

ind

ensi

ties

bet

wee

nth

etw

oli

qu

idp

has

esfo

rth

ese

par

atio

np

roce

ss.

Ch

lori

nat

edco

mp

ou

nd

sar

esu

itab

leif

aso

lven

tw

ith

ah

igh

den

sity

isto

be

use

d,

and

par

ticu

larl

ylo

w-d

ensi

tyco

mp

ou

nd

sar

efo

un

dam

ong

the

satu

rate

dhydro

carb

ons

and

ether

s.T

he

ther

ma

lst

ab

ilit

yo

fth

eso

lven

tca

nb

eh

igh

lysi

gn

ifica

nt.

Th

ere

sear

cher

har

dly

ever

fin

ds

the

answ

erto

this

qu

esti

on

inth

eli

tera

ture

and

isd

irec

ted

toca

rry

ou

th

isow

nm

easu

re-

men

t.It

isn

eces

sary

tok

now

(1)

how

mu

chso

l-ven

tm

ake-

up

wil

lb

en

eed

edin

the

pro

cess

;(2

)w

het

her

are

gen

erat

ion

pro

cess

for

con

tin

uo

us

rem

oval

of

dec

om

po

siti

on

pro

du

cts

nee

ds

tob

ein

stal

led

.V

ery

care

ful

test

sm

ust

be

carr

ied

ou

tto

fin

do

ut

wh

eth

erd

eco

mp

osi

tio

np

rod

uct

sca

nco

nta

min

ate

the

extr

acto

rh

ave

aco

rro

sive

effe

cto

nth

eco

nst

ruct

ion

mat

eria

lso

fth

ep

lan

t.S

om

e-ti

mes

the

tox

ico

log

ical

pro

per

ties

and

bio

log

ical

Page 6: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

11

deg

rad

atio

no

fa

solv

ent

hav

eto

be

con

sid

ered

[40

]. Th

evi

sco

sity

sho

uld

be

aslo

was

po

ssib

leas

this

favo

rsm

ass

tran

sfer

and

ph

ase

sep

arat

ion

.H

ow

ever

,th

isp

rop

erty

isle

sssi

gn

ifica

nt

than

tho

sem

enti

on

edab

ove.

Ifth

ep

oss

ible

solv

ents

hav

eb

een

red

uce

dto

am

anag

eab

len

um

ber

afte

rte

stin

gal

lth

eas

pec

tsth

enth

ein

div

idu

alp

rop

-er

ties

can

be

eval

uat

edw

ith

ap

oin

tsy

stem

tod

isco

ver

the

bes

tso

lven

t.T

he

surf

ace

ten

sio

nis

ano

ther

imp

ort

ant

pa-

ram

eter

bec

ause

itin

flu

ence

sth

een

erg

yd

eman

dn

eces

sary

top

rod

uce

asu

itab

led

rop

dis

per

sio

n.

Hig

hsu

rfac

ete

nsi

on

giv

esri

seto

form

atio

no

fst

able

dro

ps

and

nee

ds

ah

igh

ener

gy

inp

ut.

Aso

lven

tw

ith

ah

igh

surf

ace

ten

sio

nd

ecre

ases

the

dan

ger

of

pro

du

cin

gan

emu

lsio

n.

Th

esu

rfac

ete

nsi

on

isd

epen

den

to

nth

eco

nce

ntr

atio

no

fth

etr

ansf

erco

mp

on

ent.

Fu

rth

erp

rop

erti

essu

chas

suit

abil

ity

for

reg

ener

atio

n,

dis

po

sab

ilit

y,co

sts,

com

bu

stib

ilit

y,to

xic

ity

and

corr

osi

ven

ess

also

hav

eto

be

taken

into

acco

un

tto

sele

cta

suit

able

solv

ent.

Bo

un

du

pw

ith

solv

entse

lect

ion

isth

ech

oic

eo

fth

ed

isp

erse

dan

dth

eco

nti

nu

ou

sp

has

e,re

-sp

ecti

vel

y.D

irec

tio

no

fm

ass

tran

sfer

and

ph

ase

rati

oh

ave

tob

eta

ken

into

acco

un

t.T

he

dir

ec-

tio

no

fm

ass

tran

sfer

infl

uen

ces

the

surf

ace

ten

-si

on

and

inth

isw

ayca

np

rom

ote

or

ham

per

the

coal

esce

nce

of

dro

ps.

Th

ep

has

eto

be

dis

per

sed

sho

uld

be

the

on

ew

hic

him

ped

esth

ed

rop

co-

ales

cen

ceto

pro

du

cest

able

dro

ps,

and

the

on

ew

ith

the

hig

her

flow

rate

too

bta

ina

mas

str

ansf

erar

eaas

larg

eas

po

ssib

le.

2.5

.C

alc

ula

tio

no

fT

heo

reti

cal

Sta

ges

(→A

bso

rpti

on

,C

hap

.4

.;→

Dis

till

atio

nan

d

Rec

tifi

cati

on

,C

hap

.4

.)

Tw

op

oss

ibil

itie

sex

ist

toca

lcu

late

the

mas

str

ansf

erp

erfo

rman

ceo

fex

trac

tors

.T

he

firs

to

ne

use

sth

eco

nce

pt

of

theo

reti

cal

stag

esan

dis

bas

edo

nth

eas

sum

pti

on

that

con

cen

trat

ion

equ

i-li

bri

um

ises

tab

lish

edin

ever

yse

ctio

no

fan

ex-

trac

tor.

Th

isas

sum

pti

on

can

be

fulfi

lled

on

lyin

the

mix

er–

sett

ler

wit

hlo

ng

con

tact

tim

eso

fth

ep

has

esin

vo

lved

.In

this

con

cep

tth

eto

tal

hei

gh

to

fan

extr

acti

on

colu

mn

isg

iven

by

the

pro

du

cto

fth

en

um

ber

ofth

eore

tica

lsta

ges

(NT

S)an

dth

eh

eig

ht

equ

ival

ent

of

ath

eore

tica

lst

age

(HE

TS

).

NT

Sfo

llow

sfr

om

am

ater

ial

bal

ance

inco

mb

i-n

atio

nw

ith

the

dis

trib

uti

on

equ

ilib

riu

m;

HE

TS

dep

end

so

nfl

uid

dy

nam

ics

and

mas

str

ansf

erin

the

colu

mn

san

dco

mp

rise

sal

lre

alco

nd

i-ti

on

sas

for

inst

ance

the

con

dit

ion

so

fp

has

em

ix-

ing

.T

her

efo

reth

isco

nce

pt

isp

refe

rred

on

lyfo

rro

ug

hes

tim

atio

ns

inp

ract

ice

bec

ause

itis

easy

toh

and

lean

dsu

ffici

ent

for

pre

par

atio

no

fla

bo

ra-

tory

exp

erim

ents

.In

the

foll

ow

ing

sect

ion

s,th

em

eth

od

wil

lb

ep

rese

nte

db

yai

do

feq

uil

ibri

um

dia

gra

ms.

Th

ese

con

dp

oss

ibil

ity

isa

stre

amco

nce

pt.

Th

eco

lum

nh

eig

htre

qu

ired

for

ag

iven

thro

ug

h-

pu

tan

dco

nce

ntr

atio

ng

rad

ien

to

fp

has

esal

on

gth

eco

lum

nca

nb

eca

lcu

late

dfr

om

hei

gh

tin

-te

gra

tio

no

fa

set

of

dif

fere

nti

aleq

uat

ion

s,d

e-ri

ved

fro

ma

dif

fere

nti

alm

ater

ial

bal

ance

and

the

loca

lm

ass

tran

sfer

bet

wee

nth

eb

oth

ph

ases

.T

he

stre

amco

nce

pt

sup

pli

esth

eco

urs

eo

fco

n-

cen

trat

ion

sal

on

gth

eco

lum

nan

dis

suit

able

for

anal

ysi

so

fth

ed

yn

amic

beh

avio

ro

fa

colu

mn

and

for

tak

ing

into

acco

un

tth

ed

rop

po

pu

lati

on

insi

de

the

colu

mn

.It

isp

refe

rred

un

til

now

for

scie

nti

fic

inves

tigat

ions,

e.g.,

for

stat

ionar

ily

op-

erat

edp

uls

edsi

eve

tray

colu

mn

s[4

5],

[47

–4

9],

[51

],[6

2]an

dfo

rin

stat

ion

aril

yo

per

ated

rota

tin

gex

trac

tors

[65

],[6

8].

2.5

.1.

Sel

ecti

on

of

Ca

lcu

lati

on

Met

ho

ds

Th

eco

nd

itio

ns

for

anap

pli

cab

lem

eth

od

of

cal-

cula

tio

nar

ese

tb

yth

ep

rob

lem

tob

eso

lved

,b

yw

het

her

sim

pli

fied

assu

mp

tio

ns

are

per

mis

sib

lean

db

yth

em

ain

infl

uen

cin

gvar

iab

les

of

anex

-tr

acti

on

pro

ble

m.

Th

eyar

e,th

eref

ore

,d

iffe

ren

t.T

he

foll

ow

ing

po

ints

sho

uld

be

con

sid

ered

wh

ense

lect

ing

am

eth

od

of

calc

ula

tio

n:

1)

Do

chan

ges

inm

ass

flow

sh

ave

tob

eco

nsi

d-

ered

?2

)Is

the

dis

trib

uti

on

rati

oco

nst

ant?

3)

Isth

eco

nce

ntr

atio

ng

rad

ien

tla

rge

or

smal

l?4

)D

oes

on

lyo

ne

com

po

nen

th

ave

tob

eex

-tr

acte

d,

or

are

ther

ese

ver

alw

ith

dif

fere

nt

dis

trib

uti

on

coef

fici

ents

?

2.5

.2.

Sp

ecifi

cM

eth

od

s

Met

ho

d1

.If

the

foll

ow

ing

con

dit

ion

sar

esa

tisfi

ed:

1)

the

com

po

nen

tA

and

solv

entB

are

vir

tual

lyin

solu

ble

inea

cho

ther

,

12

Liq

uid

–Liq

uid

Extr

action

Fig

ure

8.

A)

Mat

eria

lb

alan

ceo

fa

colu

mn

cro

ssse

ctio

n;

B)

Co

rres

po

nd

ing

op

erat

ing

dia

gra

m

2)

the

chan

ges

inm

ass

flow

rate

so

fth

eex

trac

tan

dra

ffin

ate

ph

ase

are

neg

lig

ible

(e.g

.,fo

ra

low

con

ten

to

fC

inth

efe

ed)

then

the

com

po

siti

on

so

fth

ep

has

esca

nb

eex

-p

ress

edas

load

s.If

am

ater

ial

bal

ance

ism

ade

assh

ow

nin

Fig

ure

8,

the

two

load

sY

can

dX

c

ina

giv

enco

lum

ncr

oss

sect

ion

can

be

rela

ted

asfo

llow

s

YC−

YC

,S=

mF

ms·(

XC−

XC

,R

)

Wh

enp

lott

edo

nth

eeq

uil

ibri

um

dia

gra

m,

this

rela

tio

ng

ives

ast

raig

ht

lin

e,th

eb

alan

ceo

ro

per

atin

gli

ne.

Th

en

um

ber

of

theo

reti

calst

ages

req

uir

edto

ob

tain

ad

esir

edd

ecre

ase

inth

eco

n-

cen

trat

ion

of

Cfr

om

XC

,F

toX

C,R

can

be

de-

term

ined

gra

ph

ical

lyb

yco

nst

ruct

ing

ase

ries

of

step

sas

show

nin

Fig

ure

9.

Th

ere

sult

of

the

use

of

the

step

so

ften

mea

ns

that

the

load

ob

tain

edfr

om

Cin

the

raffi

nat

e(X

C,R

)d

oes

no

tco

rre-

spo

nd

toth

ere

qu

ired

load

(XC

R,re

q).

Fig

ure

8al

sosh

ow

sth

ep

osi

tio

no

fth

eb

al-

ance

lin

efo

rth

em

inim

um

extr

acta

ntra

tio

Vm

in

Vm

in=

ms,

min

/m

F

Th

ed

esir

eden

rich

men

to

fth

efe

edw

ith

Cu

s-in

gth

em

inim

um

amo

un

to

fex

trac

tan

tm

s,m

in

can

on

lyb

eac

hie

ved

wit

han

infi

nit

en

um

ber

of

stag

es.

Fig

ure

9.C

on

stru

ctio

no

fst

eps

inth

eo

per

atin

gd

iag

ram

too

bta

inth

en

um

ber

of

theo

reti

cal

stag

es(N

TS

)

Met

ho

d2

.F

igu

re1

0sh

ow

sth

eeq

uil

ib-

riu

md

iag

ram

for

the

syst

emto

luen

e–

eth

yle

ne

gly

col–

wat

eras

adouble

logar

ithm

icplo

t.T

his

typ

eo

fp

lot

isu

sefu

lif

the

dis

trib

uti

on

rati

ovar

ies

con

sid

erab

ly,d

esp

ite

low

load

ing

,an

dth

eco

nce

ntr

atio

nra

ng

eco

nsi

der

ably

exce

eds

the

des

ired

raffi

nat

ep

uri

ty.I

nth

isca

seth

eo

per

atin

gli

ne

isat

anan

gle

of

45◦.

log(

YC−

YC

,S

)

=lo

g

(

mF

mS

)

+lo

g(

XC−

XC

,R

)

Page 7: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

13

Fig

ure

10.D

eter

min

atio

nof

the

num

ber

of

stag

esfo

ra

var

i-ab

ledis

trib

uti

on

rati

oan

da

hig

hdeg

ree

of

dep

leti

on

Th

ep

osi

tio

no

fth

est

raig

ht

lin

esis

det

er-

min

edb

yth

eex

trac

tan

tra

tio

V.

Th

en

um

ber

of

req

uir

edth

eore

tica

lst

ages

can

be

det

erm

ined

by

con

stru

ctin

ga

seri

eso

fst

eps.

Met

ho

d3

.If

the

dis

trib

uti

on

rati

oK

isa

con

-st

ant,

furt

her

sim

pli

fica

tio

nis

po

ssib

le;

inan

al-

og

yw

ith

the

Co

lbu

rneq

uat

ion

(→A

bso

rpti

on

,C

hap

.4

.2.)

,th

en

um

ber

of

theo

reti

cal

stag

esN

TS

can

be

calc

ula

ted

:

NT

S=

log[

1+

(E−

1)(

XC

,F

XC

,R

+YC

,S

XC

,R

)]

logE

−1

wh

ere

the

extr

acti

on

fact

or

Eis

giv

enb

y

E=

K·m

s/m

F

IfN

TS

isk

now

nan

dth

ed

egre

eo

fd

eple

tio

nX

C,R

/XC

,F

isd

esir

ed,t

he

foll

ow

ing

equ

atio

nis

ob

tain

ed:

XC

,R

XC

,F=

(E−

1)(

1+

YC

,S

XC

,F

)

E(N

TS+

1)−

1

Th

iseq

uat

ion

can

on

lyb

eso

lved

iter

ativ

ely

;a

gra

ph

ical

solu

tio

nis

show

nin

Fig

ure

11

.

Met

ho

d4

.If

no

ne

of

the

above-

men

tio

ned

con

dit

ion

sis

sati

sfied

,an

dth

eex

trac

tio

np

rob

-le

mca

nb

eli

mit

edto

con

sid

erat

ion

of

the

thre

ekey

com

po

nen

ts,

the

calc

ula

tio

nca

nb

eca

rrie

do

ut

wit

hth

eai

do

fth

etr

ian

gu

lar

mas

sfr

acti

on

dia

gra

m.

Th

ism

eth

od

isb

ased

on

the

mix

ing

rule

sd

escr

ibed

inS

ecti

on

2.1

.1.

Th

esp

ecifi

edco

mp

osi

tio

ns

of

the

feed

Fan

dso

lven

tS

stre

ams

are

plo

tted

on

the

ph

ase

equ

ilib

riu

md

iag

ram

for

the

tern

ary

mix

ture

(Fig

.12

).F

or

mat

eria

lb

alan

ceo

fth

efe

edan

dp

rod

uct

stre

ams,

the

colu

mn

can

be

assu

med

tob

ea

sim

ple

mix

ing

ves

sel.

Th

eco

mp

osi

tio

nM

of

the

mix

ture

lies

on

the

tie

lin

eF

S;

the

po

si-

tio

no

fM

on

the

tie

lin

eis

det

erm

ined

by

the

rati

om

S:

mF

=M

F:

MS

.T

he

com

po

siti

on

so

fth

era

ffin

ate

Ran

dex

trac

tE

stre

ams

leav

ing

the

colu

mn

are

ob

tain

edfr

om

the

inte

rcep

tso

fth

eti

eli

ne

wit

hth

eb

ino

dal

curv

e.T

he

raffi

nat

eco

mp

o-

siti

on

isd

eter

min

edb

yth

ed

esir

edm

ass

frac

tio

no

fC

inth

era

ffin

ate

(xC

,R

).T

he

com

po

siti

on

of

the

extr

act

Eis

giv

enb

yth

ep

oin

tat

wh

ich

the

exte

nd

edli

ne

RM

inte

rsec

tsth

eb

ino

dal

curv

e.T

he

rati

om

R:

mE

iso

bta

ined

by

app

lyin

gth

ele

ver

rule

.T

he

qu

anti

ties

and

the

com

po

siti

on

so

fth

ein

com

ing

and

ou

tflow

ing

stre

ams

are

thu

sd

eter

min

ed.

Th

ere

qu

ired

nu

mb

ero

fst

ages

ina

cou

nte

r-cu

rren

tco

lum

nar

eo

bta

ined

by

usi

ng

the

po

le

po

intp

roce

du

re.T

he

pro

ced

ure

can

be

exp

lain

edb

yim

agin

ga

stre

amP

tom

ain

tain

the

mat

eria

lb

alan

ce.M

ixin

go

fth

isst

ream

wit

hth

era

ffin

ate

stre

amR

giv

esth

eco

mp

osi

tio

no

fth

eso

lven

tst

ream

S.

To

mai

nta

inth

em

ater

ial

bal

ance

the

extr

act

on

the

oth

erh

and

mu

stb

eco

mp

ose

do

fth

efe

edst

ream

Fan

dth

eim

agin

ary

stre

amP.

The

imag

inar

yst

ream

Pca

nth

us

be

regar

ded

asa

com

mo

nm

ixin

gp

artn

erfo

rF

and

Rto

mai

nta

inth

eco

mp

osi

tio

ns

of

Ean

dS

.Th

eco

mp

osi

tio

no

fth

eim

agin

ary

stre

amP

isre

pre

sen

ted

by

ap

oin

to

uts

ide

the

tria

ng

ula

rd

iag

ram

,th

ep

ole

po

int.

Th

eim

agin

ary

mas

sfr

acti

on

so

fth

eth

ree

com

-p

on

ents

inth

ep

ole

po

intc

anb

e>

1o

rn

egat

iv.I

fth

em

ater

ial

bal

ance

bo

un

dar

ies

for

the

ind

ivid

-u

alst

ages

are

taken

assh

ow

nin

Fig

ure

13

,th

eab

ove

pro

ced

ure

giv

esth

est

age

extr

acts

E2,E

3,

etc.

fro

mth

em

ixtu

reo

fth

eim

agin

ary

stre

amP

and

the

ind

ivid

ual

stag

era

ffin

ates

inth

ep

ro-

ceed

ing

stag

esR

1,

R2,

etc.

Th

eco

mp

osi

tio

no

fth

era

ffin

ates

R1,R

2,e

tc.a

reli

nked

toth

eco

rre-

spo

nd

ing

extr

acts

E1,E

2,e

tc.v

iath

ed

istr

ibu

tio

nra

tio

s(t

ieli

nes

).

2.5

.3.

Eva

lua

tio

no

fS

tag

e-N

um

ber

Ca

lcu

lati

on

for

Pro

cess

Des

ign

Ino

rder

tod

eter

min

eth

eo

per

atin

gco

nd

itio

ns

and

the

dim

ensi

on

so

fth

eeq

uip

men

tu

sed

for

14

Liq

uid

–Liq

uid

Extr

action

Fig

ure

11.

Dep

enden

ceo

fth

eth

eore

tica

ln

um

ber

of

stag

es,th

ed

egre

eo

fdep

leti

on

,an

dth

ey

ield

on

the

extr

acti

on

fact

or

E

Fig

ure

12.

Pole

poin

tco

nst

ruct

ion

–b

alan

ced

iag

ram

Page 8: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

15

Fig

ure

13.

Pole

poin

tco

nst

ruct

ion

–oper

atin

gdia

gra

m

extr

acti

on

,th

ere

sult

so

fse

ver

alst

age-

nu

mb

erca

lcu

lati

on

sm

ust

be

plo

tted

ina

dia

gra

msh

ow

-in

gth

ere

lati

on

ship

bet

wee

nth

eso

lven

tci

rcu

la-

tio

n,th

en

um

ber

of

stag

es,an

dth

ere

sid

ual

con

-te

nt

of

solu

tein

the

raffi

nat

e.S

uch

ad

iag

ram

issh

ow

nin

Fig

ure

14

for

mix

ture

II(s

eeal

soF

ig.6

).It

rep

rese

nts

the

extr

acti

on

of

a1

0%

so-

luti

on

of

cap

rola

ctam

intr

ich

loro

eth

yle

ne

wit

hw

ater

asth

eex

trac

tio

nso

lven

t.T

he

favo

rab

leo

per

atin

gre

gio

nis

usu

ally

loca

ted

inth

ere

gio

nw

hic

hsh

ow

sth

em

ost

pro

no

un

ced

curv

atu

re.

Oth

ervar

iab

les

(e.g

.,th

eef

fect

of

tem

per

atu

rean

dth

ere

sid

ual

load

ing

of

the

solv

ent

wit

hso

-lu

te)

may

hav

eto

be

taken

into

con

sid

erat

ion

.

3.

Ap

para

tus

3.1

.S

urv

ey

Ex

trac

tio

nap

par

atu

sca

nb

ecl

assi

fied

into

cou

n-

terc

urr

ent

colu

mns,

centr

ifugal

extr

acto

rs,

and

mix

er–

sett

lers

.A

llin

du

stri

aleq

uip

men

td

e-si

gn

su

seth

ep

rin

cip

leto

dis

per

seo

ne

of

the

two

liq

uid

sin

toth

eo

ther

ino

rder

toen

larg

eth

eco

nta

ctar

eafo

rm

ass

tran

sfer

and

toin

flu

ence

the

dro

pg

ener

atio

nb

yen

erg

yin

pu

tsu

chas

mix

-in

go

rp

uls

ing

.A

fter

the

resu

ltin

gd

rop

lets

hav

eb

een

con

tact

edw

ith

the

con

tin

uo

us

ph

ase

lon

gen

ou

gh

toal

low

the

extr

acta

ble

com

po

nen

t(s)

tom

igra

teto

the

dis

per

sed

ph

ase,

bo

thli

qu

ids

hav

eto

be

separ

ated

agai

n.

Den

siti

esw

ill

defi

ne

the

flow

dir

ecti

on

so

fth

ep

has

es:T

he

hea

vie

rli

qu

idfl

ow

sfr

om

top

tob

ott

om

,th

eli

gh

ter

on

efr

om

bo

tto

mto

top

.A

cco

rdin

gly

,th

efl

uid

sh

ave

tob

etr

ansp

ort

edto

the

app

arat

us

and

rem

oved

by

pu

mp

s.In

the

foll

ow

ing

chap

ter,

afe

wty

pic

ald

e-si

gn

sh

ave

bee

nse

lect

edfr

om

the

larg

en

um

ber

of

equ

ipm

ent

des

ign

sac

tual

lyu

sed

inin

du

stry

.A

mo

red

etai

led

trea

tmen

tca

nb

efo

un

din

lite

r-at

ure

,es

pec

iall

yin

[5]

and

[6].

3.1

.1.

Co

lum

ns

wit

ho

ut

En

erg

yIn

pu

t

Th

esi

mp

lest

extr

acto

ris

the

spra

yco

lum

n

(Fig

.15

A).

Th

esp

ray

colu

mn

ach

ieves

on

lyver

ysm

all

nu

mb

ers

of

sep

arat

ion

stag

esan

dis

rare

lyu

sed

now

aday

s.If

the

colu

mn

of

Fig

-u

re1

5A

isfi

lled

mai

nly

wit

hth

eh

eav

ier

liq

uid

,th

eli

gh

ter

liq

uid

bre

aks

atth

efe

edin

gp

oin

tin

tod

rop

sth

atri

sein

the

con

tin

uo

us

liq

uid

.D

rop

sre

ach

ing

the

inte

rfac

ear

ekep

tat

this

po

siti

on

by

con

tro

llin

gth

eb

ott

om

dis

char

ge

(LIC

).T

her

e,th

eyw

illt

hen

gra

du

ally

coal

esce

and

form

aco

n-

tin

uo

us

lay

erfl

oat

ing

on

top

of

the

con

tin

uo

us

liq

uid

.T

he

rever

sep

roce

du

reis

po

ssib

leas

wel

l,as

show

nin

Fig

ure

15

B.H

ere,

the

dis

trib

uto

ris

lo-

cate

dat

the

top

and

the

wat

erin

terf

ace,

call

edth

ep

rin

cip

lein

terf

ace,

isco

ntr

oll

edat

the

bo

t-to

mo

fth

eco

lum

nb

yfi

llin

git

mai

nly

wit

hth

eli

gh

ter

liq

uid

.In

this

case

,th

eh

eav

ier

liq

uid

isth

ed

isp

erse

do

ne,

bro

ken

into

dro

ple

tsd

esce

nd

-in

gin

the

lig

hte

rli

qu

id.

Th

ep

rin

cip

lein

terf

ace

can

be

adju

sted

atan

yh

eig

ht

(bet

wee

nto

pan

d

16

Liq

uid

–Liq

uid

Extr

action

Fig

ure

14.

Extr

acti

on

of

cap

rola

ctam

fro

ma

10

wt%

solu

tio

nin

tric

hlo

roet

hy

len

ew

ith

wat

eras

solv

ent

Fig

ure

15.

Colu

mns

wit

ho

ut

ener

gy

inp

ut

(LIC

=le

vel

ind

icat

ing

con

tro

ller

)A

)S

pra

yco

lum

n(l

igh

tp

has

ed

isp

erse

d);

B)

Pac

ked

colu

mn

(hea

vy

ph

ase

dis

per

sed

);C

)S

ieve

pla

teco

lum

n(l

igh

tp

has

edis

per

sed)

Page 9: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

17

bo

tto

m)

of

the

colu

mn

asn

eed

ed,th

us

the

hea

v-

ier

liq

uid

bei

ng

dis

per

sed

above

and

the

lig

hte

rli

qu

idb

elow

the

pri

nci

ple

inte

rfac

e.C

ou

nte

rcu

rren

tco

lum

ns

are

equ

ipp

edw

ith

sett

lin

gzo

nes

atth

eto

pan

dth

eb

ott

om

,w

ith

coal

esci

ng

aid

sp

rov

ided

ifn

eces

sary

.T

he

liq

-u

ids

sho

uld

nev

erb

efe

din

toth

eco

lum

nin

thes

ese

ttli

ng

zones

bec

ause

this

would

cause

hydro

-d

yn

amic

inst

abil

ity

of

the

colu

mn

thu

sre

du

c-in

gth

eo

per

atio

nal

per

form

ance

.T

he

dis

per

sed

liq

uid

oft

enca

nn

ot

be

sele

cted

fro

mth

eore

tica

lco

nsi

der

atio

ns,

bu

to

nly

by

aid

of

exp

erim

ents

ina

pil

otco

lum

nu

sin

gth

ere

alm

ater

ialsy

stem

.P

ack

edco

lum

ns

(str

uct

ure

dan

du

nst

ruc-

ture

d)

and

siev

ep

late

colu

mn

sh

ave

bee

nad

op

ted

fro

md

isti

llat

ion

tech

no

log

y(→

Dis

till

atio

nan

dR

ecti

fica

tio

n,

Ch

ap.

8.)

.In

pa

cked

colu

mn

sd

rop

form

atio

no

ccu

rso

nen

try

of

the

dis

per

sed

ph

ase

inth

ep

acked

bed

(Fig

.15

B).

Th

ed

rop

sri

seth

rou

gh

the

pac

ked

bed

wit

ho

utsi

gn

ifica

ntfu

rth

erd

isp

ersi

on

.How

-ev

er,

mas

str

ansf

erta

kes

pla

cem

ain

lyd

uri

ng

the

form

atio

no

fa

new

inte

rfac

ial

area

.T

his

exp

lain

sth

elo

wef

fici

ency

of

pac

ked

colu

mn

s[6

,C

hap

.8].

Ina

siev

ep

late

colu

mn

wit

hd

ow

nco

mer

s,as

show

nin

Fig

ure

15

C,t

he

lig

hte

rd

isp

erse

dp

has

eco

ales

ces

ben

eath

each

pla

teto

giv

ea

con

tin

uo

us

lay

er.I

tsbu

oy

ancy

pre

sses

the

liq

uid

thro

ug

hth

eh

ole

so

fth

esi

eve

pla

tes,

pro

du

cin

gje

tsw

hic

hd

isin

teg

rate

into

dro

ps.

Th

eco

nti

nu

ou

sli

qu

idfl

ow

sth

rou

gh

the

dow

nco

mer

sfr

om

stag

eto

stag

ean

dth

enac

ross

the

pla

tes.

Inth

eca

seo

flo

win

terf

acia

lte

nsi

on

the

lay

ers

of

coal

esce

dp

has

ear

eto

osm

all

for

asy

mm

etri

cal

op

erat

ion

of

the

pla

tes.

Th

enit

isad

van

tag

eou

sto

use

du

alfl

ow

pla

tes

wit

ho

ut

dow

nco

mer

s[5

7].

Sie

ve

pla

teco

lum

ns

hav

eth

ead

van

tag

eover

pac

ked

colu

mn

sth

atn

ewd

rop

sar

efo

rmed

atea

chtr

ay.

How

ever

,th

ed

rop

load

of

the

pla

teis

oft

enir

reg

ula

rly

dis

trib

ute

d,

esp

ecia

lly

ifth

eco

lum

nd

iam

eter

isla

rge

(mo

reth

an1

m).

Th

isis

the

reas

on

why

siev

epla

teco

lum

ns

can

reac

hef

-fi

cien

cies

of1

0–

15

%o

nly

inra

refa

vo

red

case

s.M

ore

over

,sin

ceco

lum

ns

are

gen

eral

lybu

iltw

ith

ap

late

spac

ing

of

0.3

m,e

ven

sim

ple

sep

arat

ion

sre

qu

ire

con

sid

erab

leover

all

hei

gh

ts.

Mas

str

ansf

erb

etw

een

the

two

liq

uid

sca

nb

esu

bst

anti

ally

imp

roved

by

app

lica

tio

no

fad

di-

tio

nal

mec

han

ical

ener

gy

info

rmo

fsu

per

im-

po

sed

agit

atio

no

rp

uls

atio

n,

resu

ltin

gin

hig

her

turb

ule

nce

nea

rth

ed

rop

san

den

larg

edm

ass

tran

sfer

area

du

eto

smal

ler

dro

psi

zes.

3.1

.2.

Pu

lsed

Co

lum

ns

Th

esi

mp

lest

des

ign

of

pu

lsed

colu

mn

isth

ep

uls

edsi

eve

pla

teco

lum

n(F

ig.1

6A

).A

pis

ton

pu

mp

wit

han

elec

tric

alo

ran

air-

pre

ssu

red

rive

cau

ses

the

enti

reli

qu

idco

nte

nt

of

the

colu

mn

tov

ibra

te.

Bo

thp

has

esar

eal

tern

atel

yfo

rced

thro

ugh

the

hole

sin

the

rhyth

mof

the

puls

a-ti

on

.T

he

dow

nco

mer

su

sed

inth

eco

nven

tio

nal

siev

ep

late

colu

mn

are

thu

ssu

per

flu

ou

s.T

he

dis

-p

erse

dp

has

ed

oes

no

tco

ales

ceab

ove

or

bel

ow

the

pla

tes

tog

ive

aco

nti

nu

ou

sla

yer

.T

he

pu

l-sa

tio

nsh

ock

flin

gs

the

dro

ps

off

the

pla

tefa

ster

than

wo

uld

be

po

ssib

leas

are

sult

ofo

nly

the

den

-si

tyd

iffe

ren

ce.T

his

lead

sto

afi

ne,

un

ifo

rmd

rop

dis

trib

uti

on

and

hen

ceen

larg

esth

em

ass

tran

s-fe

rar

ea.

Appli

cati

ons

are

lim

ited

by

the

physi

-ca

lp

rop

erti

eso

fth

esu

bst

ance

sco

nce

rned

and

hig

hth

rou

gh

pu

ts.

Sy

stem

sw

hic

hem

uls

ify

eas-

ily

can

no

tbe

pro

cess

edin

pu

lsed

colu

mn

sju

stas

stic

ky

and

gre

asy

liq

uid

s.F

orver

yla

rge

thro

ug

h-

pu

ts(c

olu

mn

dia

met

er>

0.6

m),

the

pu

lsed

vo

l-u

me

and

pu

lsin

gp

ow

erb

eco

me

ver

yh

igh

;h

ow

-ev

er,

pu

lsin

gu

nit

sfo

rla

rge

colu

mn

dia

met

ers

hav

eb

een

dev

elo

ped

.T

he

sep

arat

ion

effe

cto

fth

eco

lum

nd

e-cr

ease

sw

ith

incr

easi

ng

dia

met

er,

this

has

no

tyet

bee

nfu

lly

inves

tigat

ed.T

he

pla

tesp

acin

gis

50

–1

00

mm

.L

arg

erp

late

spac

ing

sfa

vo

rb

ack

-m

ixin

gan

dh

ence

red

uce

the

effi

cien

cyo

fth

eco

lum

n.

Sm

alle

rp

late

spac

ing

sle

adto

ast

ron

gd

ecre

ase

of

the

thro

ug

hp

ut.

Sie

ve

pla

tes

hav

ecy

lin

dri

cal

ho

les

and

atr

ian

gu

lar

pit

ch.

Th

ere

-la

tio

nsh

ipb

etw

een

the

frac

tio

nal

free

area

ϕ,t

he

ho

led

iam

eter

di

and

the

pit

chp

isg

iven

by

ϕ=

πd2 i/√

12p2

Fo

ru

sual

liq

uid

–li

qu

idsy

stem

ssi

eve

pla

tes

wit

hh

ole

dia

met

ers

fro

m2

to4

mm

resu

ltin

gin

free

area

so

f2

3to

40

%ar

ere

com

men

ded

[6,

Ch

ap.1

0],

the

low

erval

ue

of

23

%is

use

dfo

rh

igh

and

the

hig

her

val

ue

of

40

%fo

rlo

win

-te

rfac

ial

ten

sio

ns.

Fre

ear

eas

less

than

20

%ar

eu

sed

for

liq

uid

sw

ith

hig

her

vis

cosi

ties

[58

].T

he

pla

tem

ater

ial

has

ap

ron

ou

nce

din

flu

-en

ceo

nd

rop

form

atio

nan

dh

ence

on

the

sep

-ar

atio

nef

fici

ency

.T

he

pla

tem

ater

ial

and

ph

ase

sele

ctio

nm

ust

be

mat

ched

insu

cha

way

that

the

18

Liq

uid

–Liq

uid

Extr

action

Fig

ure

16.

Puls

edan

dre

cip

roca

tin

g-p

late

colu

mn

s(L

igh

tp

has

ed

isp

erse

d)

A)

Puls

edsi

eve-

pla

teco

lum

n;

B)

Rec

ipro

cati

ng

-pla

teco

lum

n(K

arr)

pla

tes

are

wet

ted

by

the

con

tin

uo

us

ph

ase

bu

tno

tb

yth

ed

isp

erse

dp

has

e,b

ecau

seth

isw

ou

ldle

adto

stro

ng

coal

esce

nce

effe

cts.

If,

for

exam

ple

,an

aqu

eou

sp

has

eis

tob

ed

isp

erse

din

tod

rop

s,m

etal

tray

sar

eu

nsu

itab

le,

bu

tp

last

icp

late

sar

esa

tisf

acto

ry.

Th

esh

arp

edg

edsi

de

of

the

siev

ep

late

,w

hic

his

du

eto

man

ufa

ctu

rin

g,sh

ou

ldex

-ac

tly

face

the

flow

dir

ecti

on

of

the

dis

per

sed

liq

-u

idso

that

dro

ps

wil

lsh

ear

atth

eed

ges

of

the

ho

les.

Gap

sb

etw

een

the

siev

ep

late

edg

ean

dth

eco

lum

nw

all

sho

uld

be

avo

ided

by

pre

cise

con

-st

ruct

ion

or

by

app

lyin

ged

ge-

seal

ing

elem

ents

mad

eo

fm

ater

ials

wh

ich

are

wet

ted

by

the

con

-ti

nu

ou

sli

qu

id.

Inm

ost

case

s,p

isto

np

um

ps

or

dia

ph

rag

mp

um

ps

are

use

das

the

pu

lsat

ors

.T

he

pu

lsin

gfr

equ

enci

esar

eb

etw

een

30

and

15

0m

in−

1,w

ith

pu

lsin

gam

pli

tud

esfr

om

5–

15

mm

(rel

ativ

eto

the

colu

mn

cro

ssse

ctio

n).

(Pu

lsin

gam

pli

tud

eis

defi

ned

asth

ed

ista

nce

bet

wee

nu

pp

eran

dlo

wer

cen

ter

of

the

pu

lsin

gm

oti

on

inth

eac

-ti

ve

par

to

fth

eco

lum

n.)

Th

ed

isp

erse

dp

has

eh

asto

be

fed

into

the

colu

mn

via

ad

istr

ibu

-to

r.T

he

mea

nd

rop

dia

met

ero

fth

ep

red

isp

erse

dsw

arm

sho

uld

be

larg

erth

anth

em

ean

dro

psi

zein

the

acti

ve

par

to

fth

eco

lum

n,

oth

erw

ise

the

hydro

dynam

ics

of

the

colu

mn

would

mai

nly

be

affe

cted

by

the

dis

trib

uto

r.T

he

ho

les

inth

ed

is-

trib

uto

rsh

ou

ldb

ever

ysh

arp

-ed

ged

toav

oid

ver

y

fin

ed

rop

s.E

ven

inp

acked

colu

mn

s,th

ese

pa-

rati

on

effe

ctca

nb

esu

bst

anti

ally

imp

roved

by

pu

lsin

go

fth

eco

nti

nu

ou

sp

has

e,at

the

exp

ense

of

are

du

ced

thro

ug

hp

ut.

Th

ein

crea

sed

per

for-

man

cere

sult

sfr

om

gre

ater

shea

rfo

rces

cau

s-in

ga

red

uct

ion

ind

rop

size

and

anin

crea

sein

inte

rfac

ial

area

[6,

Ch

ap.8

].A

sin

dis

till

atio

nco

lum

ns,

the

ph

eno

men

on

of

mal

dis

trib

uti

on

inra

nd

om

lyp

acked

colu

mn

so

fla

rger

dia

met

erca

nb

eover

com

eb

yu

seo

fst

ruct

ure

dp

ack

ing

s.T

hes

ep

ack

ing

sle

adto

ag

oo

dcr

oss

-sec

tio

nal

mix

ing

and

hav

ea

hig

her

cap

acit

y,ty

pic

ally

ato

tal

flow

rate

of

bo

thp

has

eso

fap

pro

xim

atel

y1

00

m3m−

2h−

1co

mp

ared

to3

0m

3m−

2h−

1fo

ra

ran

do

mly

pac

ked

colu

mn

.Str

uct

ure

dp

ack

ing

sar

ep

arti

cula

rly

suit

able

for

low

inte

rfac

ial

ten

-si

on

syst

ems

or

for

smal

ld

ensi

tyd

iffe

ren

ces;

sep

arat

ion

effi

cien

cyis

nea

rly

ind

epen

den

to

fsc

ale-

up

.Hy

dro

dy

nam

ics

and

mas

str

ansf

erp

er-

form

ance

are

wel

linves

tigat

ed[6

,Chap

.8],

[59].

Pu

lsin

gU

nit

s.T

he

use

of

pu

lsed

colu

mn

sis

curr

entl

yli

mit

edto

smal

lan

dm

ediu

mth

rou

gh

-p

uts

.Th

eco

lum

nd

iam

eter

isli

mit

edb

yth

ep

uls

-in

gu

nit

.F

or

ver

yla

rge

thro

ug

hp

uts

,th

ep

uls

edvo

lum

eb

eco

mes

sola

rge

that

the

use

of

ap

isto

np

um

pas

the

pu

lsin

gu

nit

cau

ses

dif

ficu

ltie

s.C

on

-se

qu

entl

y,p

uls

ing

un

its

hav

eb

een

dev

elo

ped

wh

ich

op

erat

ew

ith

ou

ta

pis

ton

pu

mp

.T

he

pu

l-sa

tor

dev

elo

ped

by

Mis

ek

(Fig

.17

)is

bas

edo

n

Page 10: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

19

ace

ntr

ifugal

pum

p.

The

pum

p(e

)is

connec

ted

on

bo

thth

esu

ctio

nsi

de

and

the

del

iver

ysi

de

top

ress

ure

ves

sels

wh

ich

are

alte

rnat

ely

con

nec

ted

toth

eco

lum

nb

ym

ean

so

fa

rota

tin

gval

ve

(c).

Wit

hth

eval

ve

sett

ing

show

nin

Fig

ure

17

A,

the

pu

mp

del

iver

sth

eli

qu

idin

toth

eco

lum

nv

iath

ed

isch

arg

ed

rum

(b),

tak

ing

the

rate

del

iver

edfr

om

the

suct

ion

dru

m(a

).A

fter

chan

geo

ver

of

the

val

ve

(Fig

.17

B),

the

pu

mp

del

iver

sfr

om

the

colu

mn

via

ves

sel

(a)

into

dru

m(b

).T

he

pu

mp

thu

sal

way

sd

eliv

ers

con

tin

uo

usl

yin

on

ed

irec

-ti

on

.Rev

ersa

lofth

ed

irec

tio

no

ffl

ow

inth

ep

uls

eli

ne

isef

fect

edb

yth

ech

ang

e-over

val

ve

(c)

inac

cord

ance

wit

hth

ep

uls

efr

equ

ency

.A

pu

lsat

or

bas

edo

nth

isp

rin

cip

leh

asb

een

dev

elo

ped

by

Bro

nsw

erk

/DS

M(F

ig.1

7C

),an

dis

now

ino

p-

erat

ion

for

colu

mn

sw

ith

am

axim

um

dia

met

ero

f2

.7m

.F

or

larg

epuls

edvolu

mes

,th

ehydra

uli

cpul-

sato

rfr

om

Wep

uko

[60

]is

also

suit

able

(Fig

.18

).It

isfl

ang

edd

irec

tly

toth

elo

wer

bo

tto

mo

fth

eco

lum

nen

dan

dac

tsin

the

dir

ecti

on

of

the

col-

um

nax

is.T

he

pu

lsin

gp

isto

nis

con

nec

ted

via

aco

mm

on

pis

ton

rod

toa

work

ing

pis

ton,th

ehy-

dra

uli

cd

rive

of

the

pis

ton

isa

rap

idly

rever

sib

lera

dia

lp

isto

np

um

p.

Rec

ipro

cati

ng

-Pla

teC

olu

mn

s.In

ano

ther

app

roac

hfo

rso

lvin

gth

ep

rob

lem

of

larg

eth

rou

gh

pu

ts,

the

pla

tes,

and

no

tth

eli

qu

id,

are

mad

eto

reci

pro

cate

,so

that

the

pu

lsin

gp

um

pis

elim

inat

ed.

Th

isp

rin

cip

lele

dto

the

dev

elo

p-

men

to

fth

ere

cip

roca

tin

g-p

late

colu

mn

wh

ich

can

be

regar

ded

asth

eco

nver

seof

the

puls

edsi

eve

pla

teco

lum

n.I

nth

ep

uls

edsi

eve

pla

teco

l-u

mn

,th

etr

ays

are

fixed

and

the

enti

reli

qu

idco

nte

nt

of

the

colu

mn

isca

use

dto

vib

rate

;in

the

reci

pro

cati

ng

-pla

teco

lum

n,

the

pla

tes

are

moved

.In

bo

thca

ses,

the

liq

uid

un

der

go

esan

osc

illa

tin

gm

oti

on

rela

tive

toth

ep

late

.In

the

Ka

rrco

lum

n(F

ig.1

6B

),si

eve

pla

tes

wit

ha

free

area

of

abo

ut

60

%,

a1

0–

15

mm

ho

led

iam

eter

,an

da

25

–5

0m

mp

late

spac

ing

,ar

em

ou

nte

do

na

cen

tral

shaf

t.T

he

com

ple

tep

ack

ism

oved

up

and

dow

n,

dri

ven

by

anec

-ce

nte

r.

Fig

ure

17.

Puls

ator

wit

hro

tati

ng

val

ve

A)P

rinci

ple

dia

gra

mofco

mpre

ssio

nst

roke;

B)P

rinci

ple

di-

agra

mof

suct

ion

stro

ke;

C)

Tec

hnic

aldes

ign

(Bro

nsw

erk)

a)S

uct

ion

dru

m;

b)

Dis

char

ge

dru

m;

c)R

ota

ting

val

ve;

d)

Colu

mn;

e)C

entr

ifugal

pum

p

Th

ere

lati

vel

yla

rge

free

area

of

reci

pro

cat-

ing

pla

teco

lum

ns

allo

ws

mu

chg

reat

erth

rou

gh

-p

uts

than

conven

tio

nal

pu

lsed

colu

mn

s.H

ow

-ev

er,

rece

nt

inves

tigat

ions

show

edth

atpuls

edsi

eve

pla

teco

lum

ns

can

be

equ

ipp

edw

ith

larg

erfr

eear

eas,

too

.B

oth

typ

eso

fp

uls

edco

lum

ns

show

ver

ysi

mil

arp

erfo

rman

ces

and

op

erat

ion

alb

ehav

ior

ifth

eyar

eeq

uip

ped

wit

hth

esa

me

free

area

s[6

1].

Res

earc

ho

nth

ees

tab

lish

edty

pes

of

pu

lsed

colu

mn

sh

asb

een

ver

yin

ten

sive

sin

ceth

e1

97

0s.

20

Liq

uid

–Liq

uid

Extr

action

Fig

ure

18.

Hydra

uli

cp

uls

ato

ra)

Puls

ing

pis

ton;

b)

Wo

rkin

gp

isto

n;

c)R

insi

ng

;d

)H

y-

dra

uli

cag

gre

gat

ew

ith

radia

lpis

ton

pum

p

Fig

ure

19.

Rota

ting

dis

kco

nta

cto

r(R

DC

)a)

Rota

ting

dis

k;

b)

Sta

tor

rin

g

3.1

.3.

Co

lum

ns

wit

hR

ota

tin

gIn

tern

als

Ro

tati

ng

Dis

kC

on

tact

or

(RD

C).

Inth

eR

DC

(Fig

.19

A),

stat

or

rin

gs

are

mo

un

ted

atcl

ose

inte

rval

s.D

isk

sar

efi

tted

bet

wee

nth

eri

ng

sto

aro

tati

ng

shaf

t.T

he

rota

tin

gd

isk

sfl

ing

the

dro

ps

of

the

dis

per

sed

phas

eoff

centr

ifugal

ly,

on

toth

est

ato

rri

ng

sw

her

eth

eyar

eb

raked

and

defl

ecte

d.T

he

dro

pd

istr

ibu

tio

nis

exce

llen

tan

dca

nre

ach

the

emu

lsifi

cati

on

lim

itas

the

rota

-ti

on

alsp

eed

incr

ease

s.T

he

RD

Ch

asa

rela

tivel

ysi

mp

leco

nst

ruct

ion

wit

ha

larg

efr

eecr

oss

-sec

tio

nal

area

.On

the

on

eh

and

,it

reac

hes

larg

eth

rou

gh

pu

ts,

on

the

oth

erh

and

itfa

vo

rsb

ack

mix

ing

of

ph

ases

cau

sin

ga

dec

reas

eo

fef

fici

ency

.Ala

rge

ran

ge

of

thro

ug

h-

pu

tsis

po

ssib

lew

ith

ou

tre

mar

kab

led

ecre

ase

of

effi

cien

cy.

Th

elo

adin

gli

mit

isg

ener

ally

low

erth

anin

pu

lsed

colu

mn

s.T

he

RD

Cis

un

suit

able

for

mix

ture

sw

hic

hte

nd

tofo

rmem

uls

ion

san

dfo

rp

rod

uct

sco

nta

inin

gd

irt.

Th

ese

par

atio

nef

-fi

cien

cyd

ecre

ases

shar

ply

wit

hin

crea

sin

gd

i-am

eter

.N

ever

thel

ess,

succ

essf

ul

RD

Cs

of

up

to3

50

0m

min

dia

met

erh

ave

bee

nco

nst

ruct

ed.

Th

eyar

eth

us

suit

able

for

gre

ater

thro

ug

hp

uts

than

pu

lsed

colu

mn

san

dar

ep

refe

rab

lyu

sed

too

per

ate

wit

hla

rge

pro

du

ctfl

ow

sw

hen

the

de-

man

ds

on

sep

arat

ion

per

form

ance

are

on

lylo

was

for

inst

ance

inth

eo

ilin

du

stry

or

inw

aste

wa-

ter

trea

tmen

t[4

2].

As

inp

uls

edco

lum

ns,

the

wet

tin

gb

ehav

ior

also

infl

uen

ces

dro

pfo

rmat

ion

inth

eR

DC

,an

dsh

ou

ldth

eref

ore

be

taken

into

acco

un

tw

hen

se-

lect

ing

am

ater

ial

for

the

colu

mn

inte

rnal

s.

Ku

hn

iE

xtr

act

or.

Th

eK

uh

ni

extr

acto

r(F

ig.2

0A

)u

ses

atu

rbin

eas

the

mix

ing

ele-

men

t.P

erfo

rate

dp

arti

tio

nd

isk

sse

par

ate

the

extr

acti

on

stag

esan

dre

du

ceb

ack

mix

ing

.T

his

app

arat

us

isal

sou

sed

for

per

form

ing

reac

tio

ns

bet

wee

ntw

oli

qu

idp

has

es;

the

resi

-d

ence

tim

eca

nb

ead

just

edv

iath

efr

eear

eao

fth

ep

erfo

rate

dd

isk

.

QV

F-E

xtr

act

or.

Th

eQ

VF

extr

acto

rR

ZE

(Fig

.20

B)u

ses

bla

de

stir

reras

mix

ing

elem

ents

.T

he

par

titi

on

dis

ks

hav

em

ean

der

-fo

rmed

met

alst

rip

esat

the

inn

erci

rcu

mfe

ren

ceto

red

uce

the

ph

ase

dis

per

sio

nb

ych

ann

elin

go

fb

oth

ph

ases

.T

he

op

erat

ion

alb

ehav

ior

issi

mil

arto

that

of

the

Ku

hn

iex

trac

tor

(see

Fig

.20

A).

Page 11: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

21

Fig

ure

20.

Colu

mns

wit

hro

tati

ng

inte

rnal

sA

)K

uhni

extr

acto

r;B

)Q

VF

extr

acto

r

Gra

esse

rC

on

tact

or.

Th

eG

raes

ser

con

tac-

tor

(Fig

.21

)is

ano

ther

typ

eo

fro

tati

ng

equ

ip-

men

t.H

ere,

no

to

nly

the

inte

rnal

sbu

tth

een

tire

app

arat

us

rota

te.In

tern

alh

alf-

tub

esar

efi

tted

assc

oo

pin

gel

emen

tsin

ah

ori

zon

talro

tati

ng

cyli

n-

der

.D

ue

toth

ero

tati

on

,th

eh

alf-

tub

estr

ansp

ort

par

to

fth

eh

eav

yp

has

ein

toth

eover

lyin

gli

gh

tp

has

e,an

dv

ice

ver

sa.

To

red

uce

bac

km

ixin

g,

the

extr

acto

rle

ng

this

div

ided

into

cham

ber

sb

yp

arti

tio

nd

isk

s.B

ecau

seo

fit

slo

wd

isp

ersi

ng

ef-

fect

,th

iseq

uip

men

tis

par

ticu

larl

ysu

itab

lefo

rsy

stem

sw

hic

hte

nd

toem

uls

ify.

Th

eth

rou

gh

pu

tis

low

com

par

edw

ith

oth

erex

trac

tors

.

Fig

ure

21.

Gra

esse

rco

nta

ctor

3.1

.4.

Mix

er–

Set

tler

s

Mix

er–

sett

lers

con

sist

of

sin

gle

or

sever

alst

ages

inse

ries

(Fig

.22

A),

each

stag

eco

nsi

st-

ing

of

ast

irre

dves

sel

and

ase

ttli

ng

ves

sel

(Fig

.22

B).

Var

iou

sar

ran

gem

ents

are

po

ssib

lesu

chas

cocu

rren

t,co

un

terc

urr

ent,

or

cro

ssw

ise

flow

of

ph

ases

.Th

em

ixer

–se

ttle

ris

the

on

lyex

-tr

acto

rth

atre

ach

esst

age

effi

cien

cies

of

nea

rly

10

0%

and

isal

mo

stin

sen

siti

ve

for

load

flu

ctu

-at

ion

s.T

his

extr

acto

rh

asth

ead

van

tag

eth

atb

ack

-m

ixin

gca

nb

eco

mp

lete

lyp

recl

ud

edd

ue

toth

eco

mp

lete

ph

ase

sep

arat

ion

inea

chst

age.

As

are

-su

lt,

ther

ear

en

otr

ansf

erp

rob

lem

sin

scal

e-u

p.

Th

efa

vo

rab

leef

fici

ency

isal

mo

stco

mp

lete

lyre

-ta

ined

even

for

larg

eth

rou

gh

pu

ts.

Any

nu

mb

ero

fse

par

atio

nst

ages

can

be

bu

ilt,

and

,m

ore

over

,th

rou

gh

pu

td

oes

no

tap

pea

rto

be

lim

ited

.T

hes

ead

van

tag

esac

cou

nt

for

the

wid

esp

read

use

of

mix

er–

sett

lers

inin

du

stri

alp

roce

sses

for

man

yd

ecad

es.

How

ever

,ea

rly

mix

er–

sett

ler

equ

ip-

men

tw

asver

yco

mp

lex

.E

ach

sep

arat

ion

stag

eco

nsi

sted

of

ast

irre

dves

selan

da

sett

lin

gves

sel.

Th

etw

op

has

esh

adto

be

pu

mp

edb

etw

een

the

ind

ivid

ual

stag

es.

Eac

hse

ttle

rn

eed

edan

inte

r-fa

cele

vel

con

tro

l.T

he

ho

rizo

nta

lar

ran

gem

ent

resu

lted

ina

larg

ear

eare

qu

irem

ent.

Inan

effo

rtto

over

com

eth

ese

dis

advan

tag

eso

fth

em

ixer

–se

ttle

rb

atte

ries

wit

ho

utfo

reg

oin

gan

yo

fth

eirad

van

tag

es,a

nu

mb

ero

fd

iffe

ren

tde-

sig

ns

wer

ed

evel

op

ed.

Mix

er–

sett

lers

are

use

d

22

Liq

uid

–Liq

uid

Extr

action

Fig

ure

22.

Pri

nci

ple

of

am

ixer

–se

ttle

rA

)F

low

Shee

t;B

)A

rran

gem

ent

intw

od

iffe

ren

tar

eas.

Ind

ust

rial

-sca

leeq

uip

-m

ent

isu

sed

too

bta

inex

trem

ely

hig

hth

rou

gh

-p

uts

wh

ena

smal

ln

um

ber

of

stag

esis

nee

ded

,e.

g.,

inth

eex

trac

tio

no

fm

etal

salt

s.L

abo

rato

ry-

scal

ed

evic

esar

eem

plo

yed

inp

roce

ssd

evel

op

-m

ent

toch

eck

the

nu

mb

ero

fca

lcu

late

dst

ages

asa

fun

ctio

no

fth

era

tio

solv

ent.

Lar

ge-

scal

em

ixer

–se

ttle

rsw

ere

ori

gin

ally

dev

elo

ped

toex

trac

tco

pp

erfr

om

dil

ute

aqu

e-o

us

solu

tio

ns.

Th

eb

asic

des

ign

isa

bo

x-ty

pe

mix

er–

sett

ler

acco

rdin

gto

Den

ver

(Fig

.23

).T

he

mix

ing

and

sep

arat

ing

zon

esar

eco

mb

ined

ina

sin

gle

un

itan

dar

ese

par

ated

by

anover

-fl

ow

wei

rfo

rth

eli

gh

tp

has

ean

dan

un

der

flow

slit

for

the

hea

vy

ph

ase.

Th

ein

div

idu

alst

ages

are

arra

ng

edso

that

the

ou

tlet

of

the

sett

ler

also

acts

asth

ein

let

of

the

mix

er.

Th

eag

itat

or

has

two

fun

ctio

ns,

itd

isp

erse

san

dco

nvey

sth

eli

q-

uid

ph

ases

.T

hes

efu

nct

ion

sm

ayco

nfl

ict

wit

ho

ne

ano

ther

.T

he

rate

of

rota

tio

nn

eces

sary

toover

com

eth

eco

nvey

ing

hei

gh

tm

ayb

eto

oh

igh

wh

enu

nst

able

syst

ems

mu

stb

ed

isp

erse

d,ca

us-

ing

pro

ble

ms

inp

has

ese

par

atio

n,

e.g

.,a

hig

hd

egre

eo

fen

trai

nm

ent.

Mix

ing

pu

mp

sw

ith

low

shea

rin

gfo

rces

,an

dth

us

alo

wm

ixin

gin

ten

sity

,h

ave

bee

nd

evel

op

edto

avo

idth

ese

dif

ficu

ltie

s.E

xam

ple

sar

eth

eP

um

pm

ixim

pel

ler

use

dw

ith

the

Da

vyM

cKee

mix

er–

sett

ler

(Fig

.24

A)

and

the

IMI

turb

ine

pu

mp

-mix

un

it(F

ig.2

4B

).

Fig

ure

23.

Bo

x-t

yp

em

ixer

–se

ttle

r(D

enver

)A

)S

ide

vie

w;

B)

Gro

un

dp

lain

Afu

rth

erd

evel

op

men

to

fth

eD

avy

McK

eem

ixer

–se

ttle

rh

asb

een

des

crib

ed[4

3].

Eac

hst

age

con

sist

sso

lely

of

aves

selin

wh

ich

mix

ing

and

sep

arat

ion

occ

ur.

Th

ep

rod

uct

inle

tan

dth

eag

itat

or

are

loca

ted

inth

em

idd

lean

dcr

eate

ad

isp

ersi

on

zon

e.T

he

lig

htp

has

ese

par

ates

ou

tat

the

top

and

the

hea

vy

ph

ase

atth

eb

ott

om

.In

the

Lu

rgi

tow

erex

tra

cto

r,th

eb

atte

ryo

fad

jace

nt

sett

lers

isre

pla

ced

by

asp

ace-

sav

ing

Page 12: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

23

Fig

ure

24.

Indust

rial

mix

er–

sett

lers

A)

Dav

yM

cKee

mix

er–

sett

ler;

B)

IMI

turb

ine

pum

p-m

ixunit

(cro

ssse

ctio

nA

–B

–C

–D

show

nin

the

low

erpar

t);C

)L

urg

ito

wer

extr

acto

r

tow

erd

esig

nin

wh

ich

the

sett

lers

are

arra

ng

edon

top

of

each

oth

er.E

xte

rnal

centr

ifugal

pum

ps

are

use

dfo

rm

ixin

g(F

ig.2

4C

).L

ike

all

mix

er–

sett

lers

,th

isd

evic

eis

suit

able

for

ver

yla

rge

thro

ug

hp

uts

pro

vid

edth

atth

eli

qu

idsy

stem

can

wit

hst

and

the

hig

hen

erg

yin

pu

to

fth

em

ixin

gp

um

p.

Bac

km

ixin

gto

ace

rtai

nd

egre

eis

un

-av

oid

able

since

the

stag

eshav

ehydro

dynam

icco

nn

ecti

on

s.M

ult

ista

ge

mix

er–

sett

lers

are

aval

uab

leai

din

pro

cess

dev

elo

pm

ent

on

ala

bo

rato

rysc

ale.

Th

eyca

nb

ein

teg

rate

din

“min

ip

lan

ts”;

atth

isst

age

of

dev

elo

pm

ent

no

dec

isio

nsh

ou

ldb

em

ade

wh

ich

typ

eo

feq

uip

men

tis

suit

able

for

the

larg

e-sc

ale

pla

nt.

Sev

eral

exam

ple

so

fla

b-

ora

tory

mix

er–

sett

lers

are

show

nin

Fig

ure

25

.

3.1

.5.

Cen

trif

ug

al

Ex

tra

cto

rs

Cen

trif

ugal

extr

acto

rsar

euse

dw

hen

the

den

sity

dif

fere

nce

bet

wee

nth

etw

op

has

esis

insu

ffici

ent

top

rod

uce

aco

un

terc

urr

ent

un

der

gra

vit

y.T

he

bes

tk

now

no

fth

ese

dev

ices

isth

eP

od

bie

lnia

k

cen

trif

ug

ale

xtra

cto

r(F

ig.2

6A

),in

wh

ich

cyli

n-

dri

cal

per

fora

ted

shee

tsar

eco

nce

ntr

ical

lyar

-

ran

ged

asa

com

pac

tro

tor

on

ah

igh

-sp

eed

shaf

t.T

he

hea

vy

ph

ase

isfe

din

via

the

shaf

tan

dm

oves

outw

ards

due

toth

ece

ntr

ifugal

forc

e.T

he

light

ph

ase

moves

inth

eo

pp

osi

ted

irec

tio

n.

Sim

ilar

toco

lum

ns,

eith

erth

eli

gh

tp

has

eo

rth

eh

eav

yp

has

eca

nb

ed

isp

erse

din

tod

rop

s,as

des

ired

.If

the

lig

htp

has

eis

tob

ed

isp

erse

d,th

em

ain

inte

r-fa

cem

ust

be

loca

ted

nea

rth

esh

aft.

Dep

end

ing

on

the

syst

emth

en

um

ber

of

stag

esw

hic

hca

nb

eco

mb

ined

ino

ne

un

itis

lim

ited

to3

to4

the-

ore

tica

lst

ages

.T

he

Ro

ba

telce

ntr

ifu

ga

lex

tra

cto

ris

bas

edo

na

tota

lly

dif

fere

nt

pri

nci

ple

and

allo

ws

gre

ater

nu

mb

ers

of

stag

es(F

ig.2

6B

).D

isk

sse

rvin

gas

the

mix

ing

elem

enta

rece

nte

red

on

aver

tica

lsta

-to

r.T

he

ho

usi

ng

isd

ivid

edb

yan

nu

lar

dis

ks

into

an

um

ber

of

stag

esan

dro

tate

sar

ou

nd

the

cen

tral

shaf

t.E

ach

stag

eco

nsi

sts

of

am

ixin

gch

amb

eran

da

sett

lin

gch

amb

er.

Th

ed

isk

sea

chd

ipin

toth

em

ixin

gch

amb

er.A

nex

ten

sive

rev

iew

on

op

-er

atio

nan

dca

lcula

tion

of

centr

ifugal

extr

acto

rsis

giv

enin

[6,

Ch

ap.1

4].

Cen

trif

ug

esar

em

ore

com

ple

xth

anco

lum

ns,

thei

rin

ves

tmen

tan

dm

ain

ten

ance

cost

sar

eco

r-re

spo

nd

ing

lyh

igh

.T

hey

can

ther

efo

reo

nly

stan

dco

mp

aris

on

wit

hco

lum

ns

inca

ses

wh

ere

24

Liq

uid

–Liq

uid

Extr

action

Fig

ure

25.

Lab

ora

tory

mix

er–

sett

lers

A)

Norm

agm

ixer

–se

ttle

r;B

)S

cho

tt/Q

VF

mix

er–

sett

ler

they

hav

ead

van

tag

esw

hic

hn

oco

lum

nca

np

rov

ide.

Ph

ase

sep

arat

ion

isp

oss

ible

even

insy

stem

sh

avin

ga

den

sity

dif

fere

nce

aslo

was

15

kg

/m3.S

yst

ems

wit

hla

rge

dif

fere

nce

sin

vis

-co

sity

can

be

pro

cess

ed,

sin

ceth

eh

igh

shea

rfo

rces

effe

ctin

ten

sive

mix

ing

.A

sa

resu

lto

fit

sco

mp

actd

esig

n,t

he

cen

trif

u-

gal

extr

acto

ris

asp

ace-

savin

gap

par

atus

wit

han

extr

emel

ysm

all

op

erat

ing

vo

lum

ean

da

sho

rtre

sid

ence

tim

e.T

hes

ead

van

tag

esca

nb

ed

esir

-ab

leif

exp

ensi

ve

solv

ents

or

sub

stan

ces

of

lim

-it

edst

abil

ity

are

use

d.T

he

stea

dy

stat

eis

reac

hed

soo

naf

ter

star

tin

g.

Th

isex

trac

tor

isth

eref

ore

suit

able

for

bat

chw

ise

op

erat

ion

and

freq

uen

tch

ang

eso

fp

rod

uct

s.E

xtr

acti

on

un

der

pre

ssu

res

of

up

to5

MP

ais

po

ssib

le.

3.2

.F

luid

-Dy

na

mic

Fu

nd

am

enta

ls

Aco

mp

reh

ensi

ve

trea

tmen

to

ffl

uid

-dy

nam

icfu

nd

amen

tals

isg

iven

else

wh

ere

(→F

luid

Me-

chan

ics)

.

3.2

.1.

Pro

ble

ms

an

dP

roce

ssS

tra

teg

y

InS

ecti

on

2.5

,it

was

show

nh

ow

the

nu

mb

ero

fth

eore

tica

lst

ages

and

the

flow

dia

gra

mo

fth

eu

nit

op

erat

ion

“ex

trac

tio

n”

are

calc

ula

ted

on

the

bas

iso

feq

uil

ibri

a.T

he

sele

ctio

nan

dd

esig

no

f

app

arat

us

are

bas

edo

nfl

uid

dy

nam

ics

and

are

no

tca

rrie

do

ut

un

til

the

ther

mo

dy

nam

icd

esig

nis

com

ple

ted

.Atp

rese

nt,

mo

del

exp

erim

ents

are

stil

ln

eces

sary

for

the

des

ign

of

extr

acti

on

app

a-ra

tus.

Fo

rth

isre

aso

n,

ak

now

led

ge

of

the

op

-er

atin

gch

arac

teri

stic

so

fth

evar

iou

sty

pes

of

app

arat

us

iso

fg

reat

inte

rest

soth

atth

en

um

-b

ero

fex

per

imen

tsca

nb

esu

bst

anti

ally

red

uce

d,

and

pre

sele

ctio

nan

dp

reli

min

ary

sizi

ng

can

be

carr

ied

ou

tat

are

lati

vel

yea

rly

stag

eo

fp

roce

ssd

evel

op

men

t.T

he

flu

id-d

yn

amic

des

ign

of

anap

par

atu

sis

div

ided

into

the

foll

ow

ing

area

s:

1)

Sel

ecti

on

of

suit

able

inte

rnal

sw

ith

resp

ectt

om

ater

ial

of

con

stru

ctio

n,

shap

e,an

dsi

ze.

2)

Det

erm

inat

ion

of

the

op

erat

ing

con

dit

ion

sw

ith

resp

ect

top

has

ese

lect

ion

,p

uls

ing

,an

dlo

adin

g.

3)

Siz

ing

of

the

colu

mn

dia

met

erin

acco

rdan

cew

ith

the

req

uir

edth

rou

gh

pu

tso

ffe

edan

dso

lven

t.4

)S

izin

go

fth

eco

lum

nh

eig

ht

inac

cord

ance

wit

hth

eac

tual

sep

arat

ion

pro

ble

m.

How

ever

,th

ese

fou

rp

rob

lem

sca

nn

otb

eco

n-

sid

ered

inis

ola

tio

n.T

hu

s,b

oth

the

inte

rnal

san

dth

eo

per

atin

gco

nd

itio

ns

affe

ct(1

)th

elo

adin

gli

mit

and

hen

ceth

eco

lum

nd

iam

eter

and

(2)

the

sep

arat

ion

effi

cien

cyan

dth

us

the

colu

mn

hei

gh

t.M

easu

res

for

incr

easi

ng

the

load

ing

lim

ith

ave

Page 13: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

25

anad

ver

seef

fect

on

the

sep

arat

ion

effi

cien

cy,

and

vic

ever

sa.

Fig

ure

26.

Cen

trif

ugal

extr

acto

rsA

)P

odbie

lnia

kex

trac

tor;

B)

Robat

elfo

ur-

stag

eco

unte

rcur-

rent

extr

acto

r

Th

esi

zin

go

fth

eco

lum

nd

iam

eter

dep

end

so

nth

efl

oo

din

gp

oin

t,i.

e.,

the

max

imu

mlo

ad-

ing

lim

itat

wh

ich

aco

lum

nca

nb

eo

per

ated

.O

nfl

oo

din

g,

accu

mu

lati

on

of

the

dis

per

sed

ph

ase

occ

urs

atin

div

idu

alp

oin

tsw

ith

inth

eco

lum

nan

db

lock

sco

un

terc

urr

ent

flow

.C

on

seq

uen

tly,

the

lig

ht

ph

ase

app

ears

inth

ed

isch

arg

eo

fth

eh

eav

yp

has

e,an

dv

ice

ver

sa.

Th

isp

hen

om

eno

nis

det

ecta

ble

by

ho

ldu

pm

easu

rem

ents

.On

flo

od

-in

g,th

eh

old

up

incr

ease

sco

nti

nu

ou

sly

and

ind

i-ca

tes

anu

nst

able

op

erat

ing

stat

e.

Th

efl

oo

din

gli

mit

dep

end

so

nth

ed

rop

size

.S

mal

ld

rop

sri

sele

ssra

pid

lyth

anla

rge

dro

ps

and

ther

efo

reca

use

ag

reat

erh

old

up

.T

he

mo

reen

erg

yis

sup

pli

edto

the

syst

em–

eith

erb

yp

uls

-in

go

rb

yro

tati

ng

inte

rnal

s–

the

smal

ler

are

the

dro

ps,

soth

atth

efl

oo

din

gli

mit

dec

reas

es.

Inte

rna

lsal

soef

fect

dis

per

sin

g.

Th

esm

alle

rth

eir

op

enar

ea,

the

mo

reth

efl

oo

din

gli

mit

de-

crea

ses.

Th

esi

zin

go

fth

eco

lum

nh

eig

hti

sd

eter

min

edb

yth

em

ass

tran

sfer

,w

hic

his

des

crib

edb

yth

ew

ell-

kn

ow

nm

ass-

tran

sfer

equ

atio

n:

the

rate

of

mas

str

ansf

erre

dis

equ

alto

the

pro

du

cto

fth

em

ass-

tran

sfer

coef

fici

ent,

the

mas

s-tr

ansf

erar

eaan

dth

eco

nce

ntr

atio

nd

iffe

ren

ceb

etw

een

the

two

ph

ases

.A

gre

atp

rog

ress

insc

ien

tifi

cre

-se

arch

has

bee

nac

hie

ved

asre

gar

ds

mea

sure

-m

ent

and

calc

ula

tio

no

fth

eq

uan

titi

eso

fin

flu

-en

ceo

nm

ass

tran

sfer

(see

for

inst

ance

[6],

[45

–4

9],

[51

],[6

2–

65

],[6

8].

Bu

tin

pra

ctic

e,th

evar

-io

us

infl

uen

ces

on

mas

str

ansf

erar

eb

est

sum

-m

ariz

edin

the

exp

ress

ion

“h

eig

ht

equ

ival

ent

of

ath

eore

tica

lst

age”

(HE

TS

),as

am

easu

refo

rth

ese

par

atio

nef

fici

ency

of

the

colu

mn

,as

men

-ti

on

edin

Sec

tio

n2

.5.

Mea

sure

men

tsin

pil

ot-

pla

ntco

lum

ns

wil

lb

eu

sed

bel

ow

tod

emo

nst

rate

the

way

inw

hic

hvar

-io

us

par

amet

ers

affe

ctth

elo

adin

gli

mit

and

sep

a-ra

tio

nef

fici

ency

.Th

ete

stsy

stem

sre

com

men

ded

by

the

Eu

rop

ean

Fed

erat

ion

of

Ch

emic

alE

ng

i-n

eeri

ng

(EF

CE

)ar

eu

sed

for

this

dem

on

stra

tio

n[4

4].

3.2

.2.

Op

era

tin

gC

ha

ract

eris

tics

of

Pu

lsed

Co

lum

ns

an

dC

olu

mn

sw

ith

Ro

tati

ng

Inte

rna

ls

Lo

ad

ing

Lim

it.

Fig

ure

27

show

sth

elo

ad-

ing

lim

itvC

+v D

asa

fun

ctio

no

fth

ep

uls

ing

freq

uen

cyfo

rp

late

so

fsm

all

free

area

ϕfo

rth

eto

luen

e–

wat

ersy

stem

,i.

e.,

for

hig

hin

ter-

faci

alte

nsi

on

.v c

and

vd

are

the

vo

lum

efl

ow

so

fco

nti

nu

ou

s(c

)an

dd

isp

erse

d(d

)p

has

ere

late

dto

the

tota

lcr

oss

-sec

tio

nal

area

of

the

colu

mn

,th

eso

-cal

led

sup

erfi

cial

vel

oci

ties

.T

his

flo

od

-in

gp

oin

tcu

rve

star

tsat

the

ori

gin

of

the

co-

ord

inat

es;

ino

ther

wo

rds,

wit

ho

ut

pu

lsin

g,

no

thro

ug

hp

utis

po

ssib

le.W

ith

incr

easi

ng

pu

lsin

g,

the

thro

ug

hp

utal

sori

ses

up

toa

max

imu

m.T

his

par

to

fth

ecu

rve

isca

lled

the

low

erfl

oo

din

gli

mit

;h

ere,

pu

lsin

gh

asm

ain

lya

tran

spo

rtfu

nc-

26

Liq

uid

–Liq

uid

Extr

action

tio

n.

Wit

hin

crea

sin

gfr

equ

ency

,h

ow

ever

,th

ed

isp

ersi

ng

fun

ctio

np

red

om

inat

es,th

ed

rop

sb

e-co

me

smal

ler

and

the

load

ing

lim

itfa

lls.

Th

ein

tere

stin

gre

gio

nin

pra

ctic

eis

that

inw

hic

hd

isp

ersi

ng

pre

do

min

ates

.

Fig

ure

27.

Load

ing

lim

itas

afu

nct

ion

of

the

pu

lsin

gfr

e-quen

cyat

dif

fere

nt

free

area

for

tolu

ene

–w

ater

[50

]a

=6

mm

;vd

/vc=

1△

ϕ=

0.6

0;

d=

6.5

mm

=0.4

0;

d=

4.0

mm

◦ϕ

=0.2

3;

d=

2.5

mm

As

isto

be

exp

ecte

d,

the

load

ing

lim

itri

ses

wit

hin

crea

sin

gfr

eear

eaover

the

enti

rep

uls

ing

ran

ge,

bu

tth

ep

osi

tio

no

fth

em

axim

um

rem

ain

su

nch

ang

ed.

At

the

larg

est

free

area

of

ϕ=

0.6

,a

mo

des

tth

rou

gh

pu

tis

po

ssib

leev

enw

ith

ou

tp

uls

ing

.

Fig

ure

28.

Load

ing

lim

itas

afu

nct

ion

of

pu

lsat

ion

freq

uen

cyat

dif

fere

nt

inte

rfac

ial

ten

sio

n[5

0]:

ϕ=

0.2

3;

vd

/vc=

1a)

Buta

nol–

wat

er:σ

=1

.8m

N/m

;b

)B

uty

lac

etat

e–

wat

er:

σ=

13.5

mN

/m;

c)T

olu

ene

–w

ater

=3

6.1

mN

/m

Th

eef

fect

ofth

eg

eom

etry

ofth

ein

tern

als

can

also

be

show

nfo

rp

uls

edp

acked

colu

mn

s.T

her

eis

no

low

erlo

adin

gli

mit

.Atf

req

uen

cyf

=0

,i.e

.,th

eu

np

uls

edco

lum

n,

the

load

ing

lim

ith

asit

sm

axim

um

val

ue,

and

dec

reas

esw

ith

incr

easi

ng

freq

uen

cy[5

3].

Of

all

the

physi

cal

pro

per

ties

,th

ein

terf

aci

al

ten

sio

nh

asth

eg

reat

est

effe

cto

nth

efl

uid

dy

-n

amic

so

fan

extr

acti

on

colu

mn

.Fig

ure

28

show

sa

com

par

iso

no

fth

ree

test

syst

ems

wit

hd

iffe

ren

tin

terf

acia

lte

nsi

on

s.A

sca

nb

ese

en,t

he

thro

ug

h-

pu

top

tim

um

issh

ifte

dto

hig

her

pu

lsin

gfr

equ

en-

cies

wit

hin

crea

sed

surf

ace

ten

sio

n,i

.e.,

hig

hsu

r-fa

cete

nsi

on

sn

eed

ah

igh

ener

gy

sup

ply

.In

addit

ion

toth

ephysi

cal

pro

per

ties

,th

ep

has

era

tio

isan

oth

erp

aram

eter

det

erm

ined

by

the

pro

cess

.D

ecis

ion

sca

no

nly

be

mad

eas

tow

hic

ho

fth

etw

op

has

esis

tob

ed

isp

erse

d(t

he

org

anic

or

the

aqueo

us

phas

e)an

dw

het

her

inth

eg

reat

ero

rsm

alle

rq

uan

tity

.F

igu

re2

9sh

ow

sth

eef

fect

of

the

par

amet

erv d

/vc

[52

].A

sth

ep

has

era

tio

incr

ease

s,th

eth

rou

gh

pu

td

ecre

ases

.

Fig

ure

29.

Rel

ativ

elo

adin

go

fa

pu

lsed

siev

ep

late

colu

mn

asa

fun

ctio

no

ffl

ow

rati

o[5

2]

◦T

olu

ene

–w

ater

;2

MIB

K–

wat

er;△

Bu

tyl

acet

ate

–w

ater

;�

n-B

uta

no

l–w

ater

Afu

rth

erp

aram

eter

affe

ctin

gth

elo

adin

gli

mit

and

sep

arat

ion

effi

cien

cyis

the

dir

ecti

on

of

the

mas

str

ansf

er.

Cu

rve

bin

Fig

ure

30

Ash

ow

sth

efl

oo

din

gp

oin

tcu

rve

of

the

pu

retw

o-

com

po

nen

tm

ixtu

reto

luen

e–

wat

er,

wh

ere

no

mas

str

ansf

erta

kes

pla

ce[5

4].

Cu

rve

afo

rm

ass

tran

sfer

from

the

dis

per

sed

org

anic

phas

eto

the

con

tin

uo

us

aqu

eou

sp

has

eli

essu

bst

anti

ally

hig

her

by

com

par

iso

n.

Th

ere

aso

nfo

rth

isis

anin

crea

sed

ten

den

cyto

coal

esce

nce

and

hen

cefo

rmat

ion

of

larg

erd

rop

s.In

the

conver

seca

se(m

ass

tran

sfer

fro

mth

eco

nti

nu

ou

sto

the

dis

-p

erse

dp

has

e),

the

inte

rfac

ial

ten

sio

nan

dh

ence

the

dro

psi

zear

ere

du

ced

by

the

com

po

nen

t

Page 14: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

27

bei

ng

tran

sfer

red

,le

adin

gto

alo

wer

ing

of

the

flo

od

ing

po

int

[53

],[5

5].

Th

eef

fect

of

the

di-

rect

ion

of

mas

str

ansf

ero

nth

ed

rop

size

also

cau

ses

dif

fere

nce

sin

the

sep

arat

ion

effi

cien

cy.

Inth

eca

seo

fm

ass

tran

sfer

fro

mth

eco

nti

nu

-o

us

ph

ase

toth

ed

isp

erse

dp

has

e(i

nto

the

dro

p),

smal

ler

HE

TS

val

ues

resu

lt,

i.e.

,b

ette

rse

par

a-ti

on

effi

cien

cyis

ob

tain

ed(F

ig.3

0B

).

Fig

ure

30.

Infl

uen

ceof

mas

str

ansf

eron

load

ing

lim

itan

dse

par

atio

nef

fici

ency

for

the

tolu

ene

–ac

etone

–w

ater

sys-

tem

(ϕ=

0.6

0)

△M

ass

tran

sfer

from

the

dis

per

seto

the

conti

nuous

phas

e;2

Syst

emw

ithout

mas

str

ansf

er;◦

Mas

str

ansf

erfr

om

the

conti

nuous

toth

edis

per

sephas

e

Pil

hofer

[56

]h

assh

ow

nth

atth

elo

adin

gli

mit

of

extr

acti

on

colu

mn

sd

epen

ds

on

lyo

nth

ed

rop

size

.A

cco

rdin

gly

,h

igh

load

ing

lim

its

can

be

ob

tain

edo

nly

wit

hre

lati

vel

yla

rge

dro

ps.

Sep

ara

tio

nE

ffici

ency

.H

ow

ever

too

bta

ina

hig

hse

par

atio

nef

fici

ency

ala

rge

mas

str

ansf

erar

ea,

i.e.

,th

eg

reat

est

po

ssib

leh

old

up

of

dis

-p

erse

dp

has

e,is

req

uir

ed.T

he

ho

ldu

pri

ses

wit

hd

ecre

asin

gd

rop

size

.Any

inp

uto

fen

erg

yh

asth

ep

urp

ose

of

pro

du

cin

gth

eo

pti

mal

dro

pd

isp

er-

sio

n.

Th

ein

terr

elat

ion

of

sep

arat

ion

effi

cien

cyan

dp

uls

ing

can

be

dem

on

stra

ted

by

mea

sure

-

men

tso

nth

eto

luen

e–

wat

er–

acet

on

esy

stem

,w

hic

hh

asa

hig

hin

terf

acia

lte

nsi

on

[41

].F

ig-

ure

31

show

sth

em

easu

red

hei

gh

to

fa

theo

ret-

ical

stag

e(H

ET

S)

for

this

syst

emas

afu

nct

ion

of

the

pu

lsat

ion

freq

uen

cy,f

or

the

thre

ed

iffe

ren

tp

late

typ

es(c

urv

esa

–c)

.In

allca

ses,

the

HE

TS

dec

reas

esas

exp

ecte

dw

ith

incr

easi

ng

pu

lsin

gin

ten

sity

,i.

e.,

pu

lsin

gen

han

ces

the

sep

arat

ion

effi

cien

cy.

Th

ecu

rves

show

anim

po

rtan

tin

flu

-en

ceo

fth

ep

late

geo

met

ry:

wit

hin

crea

sin

gfr

eear

ea,t

he

sep

arat

ion

effi

cien

cyd

ecre

ases

shar

ply

.

Fig

ure

31.S

epar

atio

nef

fici

ency

mea

sure

das

afu

nct

ion

of

inte

rfac

ial

tensi

on

[41]

a)–

c)T

olu

ene

–w

ater

–ac

etone;

d)

Buta

nol–

wat

er–

succ

inic

acid

=0.6

0;◦

ϕ=

0.4

0;▽

ϕ=

0.2

3

Th

ebu

tan

ol–

succ

inic

acid

–w

ater

syst

emsh

ow

sver

yfa

vo

rab

leH

ET

Sval

ues

bec

ause

ofit

sex

trem

ely

low

inte

rfac

ial

ten

sio

n(c

urv

ed

).T

he

effe

cto

ffr

eear

eais

neg

lig

ible

.T

his

mea

ns

that

,fo

rsy

stem

so

flo

win

terf

acia

lte

nsi

on

,th

efr

eear

eaca

nb

ein

crea

sed

infa

vo

ro

fh

igh

erth

rou

gh

-p

uts

,w

ith

ou

ta

sig

nifi

can

tlo

ssin

sep

arat

ion

ef-

fici

ency

.A

com

par

iso

no

fth

ese

two

syst

ems

clea

rly

show

sth

ep

ron

ou

nce

din

flu

ence

of

the

inte

rfa-

cial

ten

sio

no

nse

par

atio

nef

fici

ency

.T

his

flu

id-

dy

nam

icas

pec

tsh

ou

ldal

sob

eta

ken

into

ac-

cou

ntw

hen

sele

ctin

gso

lven

tsfo

rex

trac

tio

np

ro-

cess

es.H

ith

erto

,th

isse

lect

ion

has

bee

nm

ade

al-

mo

stex

clu

sivel

yu

nd

erth

erm

od

yn

amic

crit

eria

.

28

Liq

uid

–Liq

uid

Extr

action

Th

ere

lati

on

ship

bet

wee

np

late

geo

met

ry,in

-te

rfac

ial

ten

sio

n,

and

sep

arat

ion

effi

cien

cy,

asd

escr

ibed

her

efo

ra

pu

lsed

siev

ep

late

colu

mn

,q

ual

itat

ivel

yap

pli

esal

soto

reci

pro

cati

ng

-pla

teco

lum

ns

and

pu

lsed

pac

ked

colu

mn

s.G

ener

ally

spea

kin

g,in

syst

ems

wit

ha

hig

hin

terf

acia

lte

n-

sio

n,

par

ticu

lar

atte

nti

on

mu

stb

ep

aid

toth

ech

oic

eo

fth

ein

tern

als,

ah

igh

eren

erg

yin

pu

tis

also

nec

essa

ry.

3.2

.3.

Flu

idD

yn

am

icC

alc

ula

tio

nM

eth

od

s

Th

eca

lcu

lati

on

met

ho

ds

for

det

erm

inin

gth

elo

adin

gli

mit

can

be

clas

sifi

edin

two

cate

go

ries

.T

he

firs

tca

teg

ory

con

sist

so

fem

pir

ical

corr

ela-

tions

whic

har

ebas

edon

physi

calan

dgeo

met

ri-

cal

dat

a,an

den

erg

yin

pu

t.T

he

seco

nd

cate

go

ryis

bas

edo

nfl

uid

-dy

nam

icm

od

els

and

pre

sup

-p

ose

sk

now

led

ge

of

the

dro

psi

ze.B

oth

met

ho

dcl

asse

sar

eap

pli

cab

leo

nly

totw

o-c

om

po

nen

tsy

stem

san

dth

us

neg

lect

the

effe

cto

fm

ass

tran

s-fe

r,as

show

nin

Fig

ure

30

.T

he

effe

cts

of

wet

-ti

ng

and

of

dro

pco

ales

cen

cear

eli

kew

ise

dis

-re

gar

ded

.M

ore

over

,th

eem

pir

ical

corr

elat

ions

inp

arti

cula

rar

efr

equ

entl

yre

stri

cted

toce

rtai

ng

eom

etri

esan

dca

nn

ot

be

extr

apo

late

dto

oth

erd

esig

ns,

they

can

ther

efo

reo

nly

be

use

dto

ob

-ta

inan

app

rox

imat

ees

tim

ate.

Fo

rfi

nal

equ

ip-

men

tsi

zin

g,

anex

per

imen

tal

det

erm

inat

ion

of

the

load

ing

lim

itin

the

par

ticu

lar

typ

eo

feq

uip

-m

ent

wit

hth

eo

rig

inal

pro

cess

stre

ams

isab

so-

lute

lyn

eces

sary

.

Pa

cked

Co

lum

n.

Un

pu

lsed

pac

ked

colu

mn

sh

ave

no

ind

ust

rial

sig

nifi

can

cean

ylo

ng

er.A

re-

vie

wo

nem

pir

ical

equ

atio

ns

toca

lcu

late

ho

ldu

p,

dro

psi

ze,fl

oo

din

g,m

ass

tran

sfer

,an

dax

ial

dis

-p

ersi

on

isg

iven

in[6

,C

hap

.8].

Per

form

ance

can

be

imp

roved

by

mec

han

ical

pu

lsat

ion

of

the

con

tin

uo

us

ph

ase

atth

eex

pen

seo

fa

red

uce

dth

rou

gh

pu

t.F

or

aro

ug

hes

tim

ate,

pu

lsin

gw

ith

inre

aso

nab

lera

ng

esm

ayb

eas

sum

edto

cau

seth

elo

adli

mit

sto

fall

by

20

–3

0%

asco

mp

ared

wit

hth

eu

np

uls

edco

lum

n.S

till

,n

oeq

uat

ion

sfo

rca

l-cu

lati

on

are

kn

ow

n.

Sie

ve

Pla

teC

olu

mn

.T

he

conven

tio

nal

siev

epla

teco

lum

nhas

bee

nin

ves

tigat

edby

Pil

hofer

[66

]fo

rto

luen

e–

wat

ersy

stem

s.H

irsch

man

n[6

9]

expan

ded

the

inves

tigat

ions

of

Pil

hofer

toli

qu

idsy

stem

sw

ith

low

er

surf

ace

ten

sio

ns

and

den

sity

dif

fere

nce

sth

anto

luen

e–

wat

eran

dto

du

alfl

ow

pla

tes.

Fo

rca

l-cu

lati

on

see

[69

].

Sie

ve

Pla

tea

nd

Ro

tati

ng

Co

lum

ns.

Sp

e-ci

alem

pir

ical

equ

atio

ns

are

giv

enin

the

lit-

erat

ure

for

each

typ

eo

fex

trac

tio

nco

lum

ns

ino

rder

toca

lcu

late

the

flo

od

ing

con

dit

ion

,so

,e.

g.,

for

siev

ep

late

colu

mn

sin

[66

]an

d[6

7],

for

pu

lsed

siev

ep

late

colu

mn

sin

var

iou

sch

apte

rso

f[6

],fo

rro

tati

ng

colu

mn

sin

[6]

and

[5].

How

-ev

er,

since

import

ant

effe

cts

are

dis

regar

ded

asm

enti

on

edb

efo

re,

her

eit

wil

lb

esu

ffici

ent

toin

tro

du

cea

rou

gh

met

ho

db

ased

on

afl

uid

dy

nam

icm

od

el[6

6].

Th

em

od

el,

ori

gin

ally

de-

vel

op

edfo

ru

np

uls

edsi

eve

tray

colu

mn

s,p

roved

tob

eap

pli

cab

leto

all

typ

eso

fco

lum

ns.

Itis

as-

sum

edth

atth

eli

qu

ids

occ

upy

ash

are

of

the

cro

ss-s

ecti

on

acco

rdin

gto

thei

rh

old

up

εan

dfl

ow

tow

ard

each

oth

eras

lay

ers.

Ifth

eir

sup

er-

fici

alvel

oci

tyv

,i.

e.th

eir

vo

lum

etri

cfl

ow

rate

V

rela

ted

toth

eco

mp

lete

colu

mn

cro

ssse

ctio

nS

,is vc

=Vc S

;vd

=Vd S

(1)

they

hav

ean

effe

ctiv

evel

oci

tyv c

/(1−

ε d)

or

vd/ε

d.

Th

aty

ield

sth

ere

lati

ve

vel

oci

tyv r

,al

soca

lled

slip

velo

city

,b

etw

een

the

two

liq

uid

s

vr

=vd

ε d+

vc

1−

ε d(2

)

Eit

her

v ro

rε d

can

be

calc

ula

ted

fro

mE

qu

a-ti

on

(2)

ifo

ne

or

mo

rere

lati

on

ship

sb

etw

een

the

two

term

sar

ek

now

n.In

[45

]a

sim

ple

emp

iric

aleq

uat

ion

isg

iven

toca

lcu

late

v r

vr

vp

=(1−

ε d)k

(3a)

k=

4.6−

0.1

3ln

Ar

(3b

)

wh

en1

<A

r<

107

and

2.5

<k<

4.6

v Pis

the

ind

ivid

ual

dro

pvel

oci

tyg

iven

by

[66

]fo

rci

rcu

lati

ng

dro

ps

Re p

=K

0.1

5L

(

Ar0.5

23K−

0.1

435

L−

0.7

5)

(4a)

if 1.8

3K

0.2

75

L<

Ar<

3.9

4K

0.2

75

L

for

osc

illa

tin

gd

rop

s

Page 15: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

29

Re p

=K

0.1

5L

(

4.1

8A

r0.2

18K−

0.0

0773

L−

0.7

5)

(4b)

if Ar

>372.9

K0.2

75

L(4

c)

Th

ed

imen

sio

nle

ssn

um

ber

sar

ed

efin

edas

fol-

low

s:p

arti

cle

Rey

no

lds

nu

mb

er

Re p

=vpdp

νd

(5)

Arc

him

edes

nu

mb

er

Ar

=d3 pgc∆

η2 c

(6)

char

acte

rist

icn

um

ber

of

liq

uid

KL

=2 cσ

3

∆gη4 c

(7)

den

sity

dif

fere

nce

=|

c−

d|

(8)

Mat

hem

atic

alfo

rmu

lati

on

imp

lies

the

fact

that

anin

crea

seo

fth

efl

ow

rate

atfl

oo

din

gca

nn

ot

incr

ease

the

dro

ph

old

up

:

dvd

dε d

=0

(9a)

wh

env c

=co

nst

ant,

dvc

dε d

=0

(9b)

wh

env d

=co

nst

ant.

Wit

hE

qu

atio

n(2

)fo

rth

esl

ipvel

oci

tyv r

the

equ

atio

ns

for

calc

ula

tin

gth

esu

per

fici

alvel

oci

-ti

esvc,v d

atth

efl

oo

din

gp

oin

tar

eo

bta

ined

ina

dim

ensi

on

less

form

:

vc

(

c

∆vcg

)

1/3

=A

r−

1/3

(1−

ε d)2

(Re r

+

ε ddR

e r

dε d

)

(10a)

vd

(

c

∆vcg

)

1/3

=A

r−

1/3ε2 d

(Re r−

(1−

ε d)

dR

e r

dε d

)

(10b)

Eq

uat

ion

s(1

0a)

and

(10

b)

tog

eth

erw

ith

Eq

ua-

tio

n(3

)fo

rvr

and

Eq

uat

ion

(4)

are

the

bas

is

for

flo

od

ing

po

int

dia

gra

ms

acco

rdin

gto

Fig

-u

re3

2.

Ord

inat

ean

dab

scis

saco

nta

inth

esu

-p

erfi

cial

vel

oci

ties

vd

and

v c,

i.e.

,th

ep

has

efl

ow

rate

s,m

odifi

edby

physi

cal

dat

agro

ups

toa

dim

ensi

on

less

form

.T

he

dia

gra

msh

ow

sth

eca

lcu

late

dfl

oo

din

gcu

rves

of

circ

ula

tin

gd

rop

sas

soli

dli

nes

wit

hth

ep

aram

eter

Ar.

Das

hed

lin

eso

fco

nst

ant

ph

ase

rati

ov d

/vc

and

the

to-

tal

thro

ug

hp

ut

asth

esu

mo

fvd

and

v car

eal

sosh

ow

n.

Fig

ure

32.

Gen

eral

load

ing

dia

gra

m[5

2],

[56]

Itca

nb

ese

enfr

om

Eq

uat

ion

(4b

)th

atR

e Pis

app

rox

imat

ely

pro

po

rtio

nal

toA

r0.3

and

ther

e-fo

reto

dP

.T

hat

mea

ns

that

the

dro

pvel

oci

tyv P

isn

earl

yin

dep

end

ento

fd

rop

dia

met

erd

Pin

the

reg

ion

of

osc

illa

tin

gd

rop

s.T

her

efo

reF

igu

re3

2ca

nb

eu

sed

also

for

osc

illa

tin

gd

rop

sif

Ar

isre

pla

ced

by

KL

usi

ng

Eq

uat

ion

4c.

Oth

erw

ise

the

dia

gra

mis

val

idfo

ra

cert

ain

KL

val

ue

inth

ere

gio

no

fci

rcu

lati

ng

dro

ps,

inca

seo

fF

igu

re3

2,

KL

=1

011.

Th

ed

epen

den

ceo

fd

rop

dia

met

erd

Pu

po

np

aram

eter

so

fin

flu

ence

mu

stb

ek

now

nin

or-

der

tou

seF

igu

re3

2an

dto

calc

ula

tefl

oo

din

gcu

rves

.M

any

scie

nti

fic

inves

tigat

ions

on

dro

pd

isin

teg

rati

on

invar

iou

sex

trac

tors

are

fou

nd

inth

eli

tera

ture

,bu

to

ften

wit

ho

ut

con

sid

erin

gth

ein

flu

ence

of

mas

str

ansf

eran

dth

ein

tera

ctio

no

fd

isp

ersi

ng

and

coal

esce

nce

.F

urt

her

mo

re,

par

-ti

cula

rly

for

hig

her

inte

rfac

ial

ten

sio

nsy

stem

sa

con

sid

erab

leh

eig

ht

of

colu

mn

isre

qu

ired

tore

ach

ast

ead

y-s

tate

dro

psi

ze,

and

this

hei

gh

tvar

ies

wit

hli

qu

idsy

stem

and

inle

tar

ran

gem

ent

for

the

dis

per

sed

ph

ase.

Sin

cep

op

ula

tio

nb

al-

ance

sar

en

ot

use

din

this

intr

od

uct

ory

arti

cle,

30

Liq

uid

–Liq

uid

Extr

action

the

con

cep

to

fm

ean

dro

psi

zes

isap

pli

ed–

no

r-m

ally

rep

ort

edas

the

Sau

ter

mea

no

rsu

rfac

ep

erce

nta

ge

mea

nd

rop

size

–d

efin

edb

y

d32

=

in

pid3 p

i

in

pid2 p

i

(11

)

wh

ere

np

ire

pre

sen

tth

en

um

ber

so

fd

rop

so

fth

ecl

ass

io

fd

iam

eter

dp

i.

Fin

ally

,d

iscu

ssio

nw

ill

be

rest

rict

edto

em-

pir

ical

equ

atio

ns

by

Ku

mar

and

Hartlan

d[6

,C

hap

.17

]w

hic

hg

ive

the

bes

tfi

tto

exp

erim

enta

ld

ata

and

hav

eth

eb

road

est

ran

ge

of

val

idit

y:

Pu

lsed

siev

etr

ay

an

dre

cip

roca

tin

gex

tra

cto

r

d32

σ∆

g

=C

1e0

.74

(

h

0.0

5m

)

0.1

0

·

·[

exp

(

−3.0

0af∆

1/4

1/41/4

)

+

exp

(

−28.6

5af∆

1/4

1/41/4

)]

(12

)

Th

eb

est

val

ues

of

the

par

amet

erC

1ar

e1

.51

,1

.36

,an

d2

.01

for

no

mas

str

ansf

er,

c→

d,

and

d→

cd

irec

tio

no

ftr

ansf

er,

resp

ecti

vel

y.T

he

pro

du

cta·f

isco

nsi

der

edas

the

agit

atio

nvar

i-ab

lein

the

equ

atio

n,

sin

ceth

efi

tco

uld

no

tb

eim

pro

ved

ifa

and

fw

ere

trea

ted

sep

arat

ely.

Th

eav

erag

eab

solu

teval

ue

of

the

rela

tive

dev

iati

on

inth

ep

red

icte

dval

ues

of

d32

fro

mth

eex

per

i-m

enta

lp

oin

tsis

16

.3%

.R

ota

tin

gd

isk

extr

act

ors

d32

DR

=

(

C1

0.0

7+√

Fr R

)(

ηc

√σcD

R

)

−0.1

2

(

d c

)

0.1

6

·(

D2 R

cg

σ

)

−0.5

9

(

h DC

)

0.2

5(

D DR

)

0.4

6

(13

)

Th

eo

pti

miz

edval

ues

of

C1

are

0.6

3,0

.53

,an

d0

.74

for

no

mas

str

ansf

er,

c→

dan

dd→

cd

i-re

ctio

ns

of

tran

sfer

,re

spec

tivel

y.T

he

effe

cto

fh

old

up

isig

no

red

du

eto

lack

of

dat

a.E

qu

atio

n(1

3)

pre

dic

tsth

ed

rop

size

wit

han

aver

age

ab-

solu

teval

ue

of

the

rela

tive

dev

iati

on

of

23

%.

Ku

hn

ico

lum

ns

d32

DR

=C

1e0

.37n−

0.1

1S

[0.1

4+

exp

(−18.7

3F

r R)]·

·(

ηc

√σcD

R

)

−0.2

0(

D2 R

cg

σ

)

−0.2

4

(14

)

Th

eval

ues

of

the

con

stan

tC

1ar

e9

.81×

10−

2

for

no

mas

str

ansf

eran

dc→

dtr

ansf

eran

d0

.31

for

d→

ctr

ansf

er.

Th

est

age

nu

mb

ernS,

wh

ich

var

ies

fro

m2

to1

7in

the

pre

sen

tse

to

fd

ata,

show

sa

rath

erw

eak

effe

cto

nd

rop

size

.E

qu

a-ti

on

(14

)p

red

icts

the

dro

pd

iam

eter

wit

han

av-

erag

eab

solu

teval

ue

and

rela

tive

dev

iati

on

of

17

.6%

.

3.3

.A

pp

ara

tus

Des

ign

Ex

trac

tio

nap

par

atu

sca

nb

eap

pro

xim

ativ

ely

des

ign

edp

ure

lyb

yca

lcu

lati

on

usi

ng

flu

id-

dy

nam

icm

od

els

[49

],[7

0].

Fo

rre

liab

led

esig

n,

how

ever

,p

ilo

t-sc

ale

test

sar

ein

dis

pen

sab

le.

Ifp

oss

ible

,th

ete

stsh

ou

ldb

eca

rrie

do

ut

wit

hth

eo

rig

inal

op

erat

ing

mix

ture

inth

ety

pe

of

app

ara-

tus

wh

ich

isal

soen

vis

aged

for

the

larg

e-sc

ale

un

it.

Des

irab

ly,

the

geo

met

ryo

fth

ein

tern

als

sho

uld

be

the

sam

ein

the

pil

ot-

scal

ean

din

du

s-tr

ial

app

arat

us.

How

ever

,th

isco

nd

itio

nca

nn

ot

alw

ays

be

sati

sfied

.G

ener

ally

,a

colu

mn

dia

me-

ter

of

atle

ast6

0–

80

mm

isn

eces

sary

for

des

ign

test

s.T

ests

insm

alle

rco

lum

ns

can

no

tb

eu

sed

asth

eb

asis

for

equ

ipm

ent

sizi

ng

(fo

rcr

iter

iao

neq

uip

men

tse

lect

ion

,se

eS

ecti

on

3.4

).T

he

nu

mb

ero

fte

sts

can

,h

ow

ever

,b

esu

bst

anti

ally

red

uce

dif

kn

ow

led

ge

of

the

op

erat

ing

char

ac-

teri

stic

sis

uti

lize

d.

The

physi

cal

dat

aan

dth

ephas

era

tio

are

de-

term

ined

by

the

pro

cess

use

d,th

efo

llow

ing

pa-

ram

eter

sar

eav

aila

ble

for

op

tim

izat

ion

:p

uls

ing

or

rota

tio

n,

geo

met

ryo

fth

ein

tern

als,

mat

eria

lo

fth

ein

tern

als,

and

ph

ase

sele

ctio

n,i.

e.,th

ed

i-re

ctio

no

fm

ass

tran

sfer

.E

ner

gy

inp

ut

and

the

geo

met

ryo

fth

ein

tern

als

are

sele

cted

on

the

ba-

sis

of

the

physi

cal

dat

a.

3.3

.1.

Inte

rna

lsa

nd

Op

era

tin

gC

on

dit

ion

s

Th

efo

llow

ing

gu

idel

ines

app

lyfo

rth

ese

lect

ion

of

the

free

area

inp

uls

edco

lum

ns.

An

incr

ease

inth

efr

eear

eais

reco

mm

end

edin

syst

ems

wit

ha

low

inte

rfac

ialte

nsi

on

wh

ere

itle

ads

toa

gre

atre

du

ctio

nin

the

colu

mn

vo

lum

e.A

tm

od

erat

ein

terf

acia

lte

nsi

on

,th

eco

lum

nd

iam

eter

can

be

red

uce

db

ya

gre

ater

free

area

,bu

tat

the

exp

ense

of

the

colu

mn

hei

gh

t.In

the

case

of

extr

emel

y

Page 16: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

31

Fig

ure

33.

Sel

ecti

on

of

phas

esan

dpla

tem

ater

ials

hig

hin

terf

acia

lte

nsi

on

,th

ere

isn

op

oin

tin

in-

crea

sin

gth

efr

eear

ea.

Th

em

ater

ial

of

the

inte

rnal

ssh

ou

ldb

ese

-le

cted

soth

atth

eco

nti

nu

ou

sp

has

e,bu

tn

ot

the

dis

per

sed

ph

ase,

wet

sth

ep

late

s.A

sa

rule

of

thu

mb

,m

etal

pla

tes

can

be

use

dw

hen

the

or-

gan

icphas

eis

dis

per

sed;

ifth

eaq

ueo

us

phas

eis

dis

per

sed

,th

ein

tern

als

sho

uld

be

of

pla

stic

,b

oth

inp

uls

edco

lum

ns

and

inro

tary

-ag

itat

edco

lum

ns.

Ind

ecid

ing

wh

ich

ph

ase

sho

uld

be

dis

per

sed

,th

ed

irec

tio

no

fm

ass

tran

sfer

mu

stb

eta

ken

into

acco

un

t.In

acco

rdan

cew

ith

Fig

ure

30

,m

ass

tran

sfer

sho

uld

be

fro

mth

eco

nti

nu

ou

sp

has

eto

the

dis

per

sed

ph

ase,

ifp

oss

ible

.In

the

fin

alp

has

ese

lect

ion

,how

ever

,flu

id-d

yn

amic

con

sid

-er

atio

ns

freq

uen

tly

con

flic

tw

ith

op

erat

ing

and

safe

tyre

qu

irem

ents

.T

he

po

siti

on

of

the

inte

r-fa

cein

the

colu

mn

det

erm

ines

the

ph

ase

wh

ich

isd

isp

erse

d.F

igu

re3

3su

mm

ariz

esth

ep

oss

ible

com

bin

atio

ns.

Th

ese

par

atio

nef

fici

ency

det

erm

ines

the

col-

um

nh

eig

hta

nd

the

load

lim

itd

eter

min

esth

eco

l-u

mn

dia

met

er.F

or

op

tim

izat

ion

,th

etw

op

aram

-et

ers

are

rela

ted

by

the

rati

=H

ET

S/(vc+

v d)

wh

ich

can

be

use

dto

op

tim

ize

the

colu

mn

in-

tern

als

and

ener

gy

inp

ut.

Am

inim

um

val

ue

of

this

exp

ress

ion

iseq

uiv

alen

tto

am

inim

um

col-

um

nvo

lum

e.F

igu

re3

4sh

ow

sth

ato

pti

mu

mp

uls

ing

iso

bta

ined

bet

wee

nth

em

axim

um

of

the

flo

od

ing

po

int

curv

ean

dth

em

inim

um

of

the

HE

TS

curv

e.A

nan

alo

go

us

pro

ced

ure

isu

sed

for

rota

ryag

itat

edco

lum

ns.

Th

ed

esig

np

oin

tfo

rin

du

stri

al-s

cale

colu

mn

sis

cho

sen

tob

e7

5–

80

%o

fth

elo

adli

mit

.T

he

op

erat

ing

po

int

wit

hre

spec

tto

load

and

pu

lsin

g(r

ota

tio

n)

isfi

xed

by

this

pro

ced

ure

.

3.3

.2.

Co

lum

nD

iam

eter

Ass

um

ing

the

sam

eco

lum

ng

eom

etry

,th

esp

e-ci

fic

thro

ug

hp

uto

fth

ete

stco

lum

nis

ado

pte

dfo

rth

ela

rge-

scal

eco

lum

n.

(vc

+vd) 2

=(v

c+

vd) 1

wit

h

(vc

+vd) 1

=0.7

5·(

vc

+vd) 1

max

Ind

ex1

=p

ilo

tsc

ale

Ind

ex2

=la

rge

scal

e

Th

isg

ives

the

colu

mn

dia

met

er:

D2=

√ √ √ √

4(

mF

F

+m

S

S

)

2

π·(

vc

+vd) 2

32

Liq

uid

–Liq

uid

Extr

action

Fig

ure

34.

Opti

miz

atio

no

fp

uls

atio

n

3.3

.3.

Co

lum

nH

eig

ht

Th

ese

par

atio

nef

fici

ency

of

all

colu

mn

sd

e-cr

ease

sw

ith

incr

easi

ng

colu

mn

dia

met

er,

be-

cau

seth

ere

sid

ence

tim

ed

istr

ibu

tio

ns

of

the

ph

ases

incr

ease

.T

her

efo

reval

ues

of

the

hei

gh

to

fa

theo

reti

cal

stag

e,m

easu

red

for

ala

bo

rato

ryco

lum

n,n

eed

tob

eco

rrec

ted

by

emp

iric

alsc

ale-

up

equ

atio

ns

tob

eap

pli

cab

lefo

rin

du

stri

al-s

cale

colu

mns.

How

ever

,sc

ienti

fic

inves

tigat

ions

of

this

pro

ble

mar

era

ther

po

or

and

mai

nly

emp

iri-

calk

now

led

ge

ofin

du

stri

alen

gin

eers

exis

ts.T

he

dif

fere

nt

chap

ters

of

[5]

list

form

ula

efr

om

ex-

per

ien

cew

ith

cou

nte

rcu

rren

tex

trac

tors

asd

e-sc

rib

edh

ere,

incl

ud

ing

Pu

lsed

siev

etr

ay

colu

mn

s[7

1]

HE

TS2

HE

TS1

=ex

p[1

.64

(D2−

D1)]

(15

)

(in

Eq

uat

ion

15

the

fact

or1

.64

,giv

enb

yT

horn

-

ton

,is

on

lyval

idfo

rsm

all

colu

mn

s.F

igu

re3

5sh

ow

san

emp

iric

ald

epen

den

ceo

fth

eT

ho

rnto

nfa

cto

rfr

om

the

colu

mn

dia

met

erp

ub

lish

edb

yR

eis

sin

ger

[49

])R

ecip

roca

tin

gco

lum

ns

[72

]

HE

TS2

HE

TS1

=

(

D2

D1

)

0.3

8

(16

)

Wh

enth

ep

late

geo

met

ryan

dam

pli

tud

eo

fth

ev

ibra

tio

nar

ele

ftu

nch

ang

edin

the

larg

e-sc

ale

colu

mn

,th

efr

equ

ency

sho

uld

be

red

uce

d,

acco

rdin

gto

:

f2

f1

=

(

D1

D2

)

0.1

4

Th

efo

llow

ing

app

lies

tost

irre

dco

lum

ns

[73

]:

HE

TS2

HE

TS1

=

(

D2

D1

)

0.3

3

Fig

ure

35.

Dep

end

ence

of

Th

orn

ton

fact

or

on

colu

mn

di-

amet

er

3.4

.C

rite

ria

for

Eq

uip

men

tS

elec

tio

n

Fo

ra

giv

ense

par

atio

np

rob

lem

,eq

uip

men

tis

sele

cted

esse

nti

ally

acco

rdin

gto

thre

ecr

iter

ia:

physi

cal

pro

per

ties

,re

quir

ednum

ber

of

separ

a-ti

on

stag

es,

and

thro

ug

hp

ut.

Fu

rth

ero

per

atin

gas

pec

tsar

efr

equ

entl

yim

po

rtan

t,fo

rex

amp

le,

flex

ibil

ity

regar

din

glo

advar

iati

ons

or

pro

duct

qu

alit

y,se

nsi

tiv

ity

tosm

all

amo

un

tso

fso

lid

s,su

itab

ilit

yfo

rb

atch

op

erat

ion

.T

he

physi

cal

pro

per

ties

of

inte

rest

inex

trac

-ti

on

are

the

den

sity

dif

fere

nce

bet

wee

nth

etw

o

Page 17: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

33

Fig

ure

36.C

om

par

ison

of

the

num

ber

of

theo

reti

cal

stag

esN

TS

indep

enden

ceof

tota

llo

adfo

rK

uhni,

QV

F,K

arr

and

puls

edsi

eve

pla

teex

trac

tors

(PS

E)

[64]

(syst

embuty

lac

etat

e–

wat

er–

acet

one,

phas

era

tio

vd

/vc≈

1.1

2,

mea

sure

men

tsof

var

ious

auth

ors

cite

din

[64])

ph

ases

,th

eir

vis

cosi

ty,

and

inte

rfac

ial

ten

sio

n.

Th

ese

thre

ep

aram

eter

saf

fect

dis

per

sib

ilit

yan

dp

has

ese

par

atio

nb

ehav

ior.

Hig

hd

ensi

tyd

iffe

ren

ce,

vis

cosi

ty,

and

inte

r-fa

cial

ten

sio

nm

ake

dis

per

sin

gm

ore

dif

ficu

lt;

syst

ems

wit

hsu

chphysi

cal

pro

per

ties

requir

ea

hig

her

dis

sip

atio

no

fen

erg

yth

anin

the

conver

seca

se.P

has

ese

par

atio

nis

favo

red

by

ah

igh

den

-si

tyd

iffe

ren

cean

din

terf

acia

lte

nsi

on

,w

her

eas

ah

igh

vis

cosi

tym

akes

ph

ase

sep

arat

ion

mo

red

iffi

cult

.

Th

elo

wer

lim

itfo

rth

ed

ensi

tyd

iffe

ren

ceca

nb

eta

ken

tob

e5

0k

g/m

3.

Mix

ture

sw

ith

hig

her

den

sity

dif

fere

nce

sca

ng

ener

ally

be

pro

cess

edin

colu

mn

san

dm

ixer

–se

ttle

rs.

Ifth

ed

ensi

tyd

if-

fere

nce

issm

alle

r,a

centr

ifugal

extr

acto

rm

ust

be

use

d.

Alo

win

terf

acia

lte

nsi

on

lead

sto

ph

ase

sep

-ar

atio

np

rob

lem

s.In

ind

ust

rial

un

its,

app

rox

i-m

atel

=1

–2

mN

/mca

nb

eta

ken

asth

elo

wer

lim

it.

Th

eref

ore

,m

ixer

–se

ttle

rsca

nce

rtai

nly

no

tbe

use

dfo

rm

ixtu

res

ofre

lati

vel

ylo

win

terf

a-ci

alte

nsi

on

;bec

ause

ofth

esh

earfi

eld

gen

erat

ed,

centr

ifugal

extr

acto

rsal

sohav

ea

dis

per

sing

ef-

fect

wh

ich

sho

uld

no

tbe

un

der

esti

mat

ed.I

nsu

chca

ses,

the

ener

gy

inp

ut

mu

stb

ever

yca

refu

lly

con

tro

lled

.R

ota

ry-a

git

ated

colu

mn

san

dp

uls

edco

lum

ns

can

be

use

d,in

wh

ich

the

ener

gy

inp

ut

can

be

adap

ted

toth

ephysi

cal

pro

per

ties

by

the

spee

do

fro

tati

on

or

the

pu

lse

freq

uen

cy.

Th

ese

lect

ion

ofeq

uip

men

tis

also

affe

cted

by

the

nu

mb

ero

fth

eore

tica

lst

ages

(NT

S)

req

uir

edfo

ra

giv

ense

par

atio

np

rob

lem

.On

lysm

alln

um

-b

ers

of

theo

reti

cal

stag

esca

nb

eac

hie

ved

inco

lum

ns

wit

ho

ut

ener

gy

inp

ut,

bec

ause

of

thei

rp

oo

rse

par

atio

nef

fici

ency

.P

uls

edco

lum

ns

and

rota

ryag

itat

edco

lum

ns

giv

eh

igh

ern

um

ber

so

fse

par

atio

nst

ages

.T

hey

are

lim

ited

by

the

pu

lsin

gu

nit

so

rb

yth

ele

ng

ths

of

the

con

tin

-uous

shaf

t.In

centr

ifugal

extr

acto

rs,

the

Ro-

bat

eld

esig

np

rov

ides

mo

rese

par

atio

nst

ages

than

,fo

rex

amp

le,

the

Po

db

ieln

iak

extr

acto

r.M

ixer

–se

ttle

rsar

eco

nst

ruct

edin

mo

du

les

soth

atth

ere

isv

irtu

ally

no

lim

itto

the

nu

mb

ero

fse

par

atio

nst

ages

.

Afi

rst

esti

mat

eo

fth

em

axim

um

po

ssib

leth

rou

gh

pu

tsin

the

ind

ivid

ual

extr

acto

rty

pes

can

be

ob

tain

edb

yco

nsi

der

ing

the

larg

estd

iam

eter

s(D

max)

wh

ich

hav

eh

ith

erto

bee

nin

stal

led

:

Dm

ax

,m

Rec

ipro

cati

ng

-pla

teco

lum

n1

.5

Pu

lsed

colu

mn

2.7

Ku

hn

iex

trac

tor

2.5

QV

Fex

trac

tor

2.8

Ro

tati

ng

Dis

kE

xtr

acto

r3

.0

Mix

er–

sett

ler

tow

er8

.0

34

Liq

uid

–Liq

uid

Extr

action

Fig

ure

37.C

om

par

iso

no

fef

fici

ency

ver

sus

load

of

pac

ked

colu

mn

sw

ith

and

wit

ho

ut

pu

lsin

gan

dp

uls

edsi

eve

tray

extr

acto

rsa·f

=puls

atio

nin

ten

sity

,Bf

=fl

oo

din

glo

ad,ϕ

=re

lati

ve

free

area

Acc

ord

ing

ly,

the

hig

hes

tth

rou

gh

pu

tsca

ncl

earl

yb

eac

hie

ved

wit

hth

em

ixer

–se

ttle

r.In

pu

lsed

colu

mn

s,th

ed

iam

eter

isli

mit

edb

yth

ep

uls

ing

un

it.In

rota

tio

nco

lum

ns,

the

sep

arat

ion

effi

cien

cyat

larg

ed

iam

eter

sis

no

lon

ger

sati

s-fa

cto

ry.

How

ever

,in

form

atio

ns

abo

ut

max

imal

cro

ss-s

ecti

on

allo

ads

wh

ich

are

nec

essa

ryto

ob

-ta

ind

efin

itiv

eth

rou

gh

pu

td

ata

of

aty

pe

of

ex-

trac

tor

are

no

tg

iven

inth

eli

st.

Th

eli

tera

ture

con

tain

sso

me

pu

bli

cati

on

sw

hic

hre

com

men

dcr

iter

iafo

rth

ese

lect

ion

of

the

bes

tap

par

atu

s.H

ow

ever

,m

ost

of

thes

ere

c-o

mm

end

atio

ns

are

on

lyq

ual

itat

ive,

and

som

ear

eev

enco

ntr

adic

tory

;n

ost

ud

ies

of

app

arat

us

hav

eso

faral

low

edan

ob

ject

ive

com

par

iso

n.O

nly

the

stan

dar

diz

atio

no

fte

stsy

stem

sfo

rex

trac

tio

nh

asal

low

edfl

uid

-dy

nam

icst

ud

ies

tob

eca

rrie

do

ut

un

der

com

par

able

con

dit

ion

s[4

4].

Th

efo

llow

-in

gsy

stem

sh

ave

bee

nre

com

men

ded

:

To

luen

e–

wat

er–

acet

on

eB

uty

lac

etat

e–

wat

er–

acet

on

eB

uta

no

l–w

ater

–su

ccin

icac

id

Th

ese

syst

ems

pro

vid

ean

ob

ject

ive

bas

isfo

rco

mp

aris

on

ofeq

uip

men

t.N

ever

thel

ess,

inves

ti-

gat

ions

by

dif

fere

nt

auth

ors

are

not

alw

ays

mu-

tual

lyco

mp

arab

lew

ith

resp

ect

toth

eab

solu

teH

ET

Sval

ues

.E

vid

entl

y,th

eco

lum

nle

ng

than

dth

ep

has

era

tio

hav

ean

un

exp

ecte

dly

larg

eef

fect

.F

or

the

tolu

ene

syst

em,Pil

hofer

com

par

edth

ed

iffe

ren

to

per

atin

gch

arac

teri

stic

so

fvar

i-o

us

gro

up

so

feq

uip

men

t.A

nal

og

ou

sst

ud

ies

on

the

liq

uid

syst

embu

tylac

etat

e–

wat

er–

acet

on

ew

ere

carr

ied

ou

tb

yG

oldm

an

n[6

4].

Fig

ure

36

show

sa

dia

gra

mo

fG

oldm

an

nw

ith

the

nu

mb

ero

fth

eore

tica

lst

ages

NT

Sp

erm

eter

of

colu

mn

hei

gh

t,as

afu

nct

ion

of

the

load

.T

he

fig

ure

con

-ta

ins

dat

afo

rQ

VF

and

Ku

hn

ico

lum

ns

–th

ela

t-te

rw

ith

five

dif

fere

ntfr

eear

eas

of

the

per

fora

ted

par

titi

on

dis

ks

–an

dfo

rp

uls

edsi

eve

pla

teex

-tr

acto

rs(P

SE

)w

ith

five

dif

fere

ntf

ree

area

and

on

ere

cip

roca

tin

gco

lum

n(K

arr)

.Th

ero

tary

agi-

tate

dco

lum

ns

ofQ

VC

and

Ku

hn

iwit

hth

esm

all-

est

free

area

clea

rly

ach

ieve

the

hig

hes

tN

TS

val

ues

,bu

tal

low

on

lylo

wlo

ads.

Als

o,th

eo

ther

Ku

hn

ico

lum

ns

show

hig

her

NT

Sval

ues

than

the

Page 18: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

35

pu

lsed

colu

mn

sbu

tsm

alle

rra

ng

eso

flo

ad.G

en-

eral

lysp

eak

ing

,all

mea

sure

sw

hic

him

pro

ve

the

sep

arat

ion

effi

cien

cyre

du

ceth

elo

adca

pac

ity.

Aco

mp

aris

on

bet

wee

np

uls

edsi

eve

tray

san

dst

ruct

ure

dp

ack

ing

sw

ith

the

test

syst

emto

luen

e–

wat

er–

acet

on

ew

asp

ub

lish

ed[7

4].

Fig

ure

37

show

sth

ed

iag

ram

wit

hth

eex

trac

tor

effi

cien

cyin

dep

end

ence

on

the

load

.It

iso

bv

i-o

us

that

stru

ctu

red

pac

kin

gs

hav

eth

eb

road

est

ran

ge

of

load

cap

acit

yan

dre

ach

the

sam

eo

rh

igh

eref

fici

enci

esas

pu

lsed

siev

etr

ays.

Fro

mth

ere

sult

sfo

rtw

ost

ruct

ure

dp

ack

ing

sw

ith

ou

tp

uls

atio

nth

ep

osi

tive

infl

uen

ceo

fp

uls

ing

can

clea

rly

be

seen

:T

he

pu

lsed

un

stru

ctu

red

pac

k-

ing

,Pal

lri

ng

s1

15

mm

,has

acl

earl

ysm

alle

rlo

adra

ng

e.In

Fig

ure

38

,th

era

ng

eo

flo

ads

isco

mp

ared

for

siev

etr

ays

and

stru

ctu

red

pac

kin

gs

wit

hp

ul-

sati

on

[75

].A

cco

rdin

gto

that

,p

acked

colu

mn

sh

ave

sig

nifi

can

tad

van

tag

es.

As

show

nin

[75

],th

ein

ves

tmen

tco

sts

of

pu

lsed

stru

ctu

red

pac

ked

colu

mn

sar

e3

0%

low

erth

anth

eo

nes

of

pu

lsed

siev

etr

ayco

lum

ns

and

40

to5

0%

low

erth

anp

uls

edu

nst

ruct

ure

dp

acked

colu

mn

s.

Fig

ure

38.

Ran

ge

of

load

of

puls

edst

ruct

ure

dpac

ked

colu

mns

inco

mpar

ison

topuls

edsi

eve

tray

colu

mns

inde-

pen

den

ceofth

em

ass

den

sity

dif

fere

nce

foraq

ueo

us

syst

ems

and

syst

ems

sim

ilar

tow

ater

In[7

6]

asy

stem

atic

stu

dy

on

extr

acto

rse

lec-

tio

nis

giv

en.

Ad

ap

tati

on

of

the

Co

lum

nG

eom

etry

toth

eS

epa

rati

on

Pro

ble

m.

Inth

eea

rly

day

so

fex

trac

tio

n,

var

iou

sty

pes

of

app

arat

us

wer

ere

-st

rict

edto

clea

rly

defi

ned

geo

met

ries

and

wer

eth

us

shar

ply

dis

tin

gu

ish

edfr

om

on

ean

oth

er.R

e-ce

nt

app

arat

us

dev

elo

pm

ents

allo

wad

apta

tio

n

of

the

colu

mn

geo

met

ryto

physi

cal

dat

a,both

forp

uls

edco

lum

ns

and

rota

ry-a

git

ated

colu

mn

s.T

he

bo

un

dar

ies

are

thu

sn

olo

ng

erd

isti

nct

and

ag

ener

alfl

uid

-dy

nam

icd

escr

ipti

on

of

rela

ted

typ

eso

fap

par

atu

sis

feas

ible

.T

he

op

tim

izat

ion

of

op

erat

ing

con

dit

ion

san

dth

eg

eom

etry

of

the

inte

rnal

sis

aseq

ual

lyim

po

rtan

tas

the

sele

ctio

no

fa

suit

able

typ

eo

fap

par

atu

s.In

pra

ctic

eth

efi

nal

sele

ctio

no

feq

uip

men

tis

oft

enb

ased

on

pro

du

ct-s

pec

ific

con

dit

ion

so

rp

lan

tre

qu

irem

ents

wh

ich

incl

ud

ese

nsi

tiv

ity

toso

lid

s,te

nd

ency

of

the

pro

du

ctto

po

lym

eriz

e,an

dsa

fety

aspec

ts,

for

exam

ple

wit

hre

gar

dto

solv

ent

ho

ldu

p.

Un

typ

ica

lO

per

ati

ng

Co

nd

itio

ns.

Usu

ally

extr

acto

rso

per

ate

wit

hn

earl

yth

esa

me

vo

l-u

me

flow

for

bo

thli

qu

ids

and

for

liq

uid

sw

ith

vis

cosi

ties

sim

ilar

toth

ato

fw

ater

.T

her

efo

re,

the

equ

atio

ns

giv

enb

efo

rear

eo

nly

val

idfo

rsu

chco

nd

itio

ns.

So

me

app

roac

hes

for

un

typ

ical

op

erat

ing

con

dit

ion

sar

eg

iven

bel

ow

.R

au

sch

er

[62]in

ves

tigat

edpuls

edsi

eve

tray

extr

acto

rsw

ith

ph

ase

rati

os

bet

wee

n0

.06

and

10

and

the

liq

uid

syst

emn

-bu

tylac

etat

e(o

)–

wat

er(d

)–

met

hyl

isopro

pyl

ket

one

(MIP

K),

whic

hen

rich

esM

IPK

ineq

uil

ibri

um

pre

fera

ble

inth

eorg

anic

phas

e.H

eco

nfi

rmed

the

exper

ience

that

the

sep

arat

ion

effi

cien

cyd

ecli

nes

for

ph

ase

ra-

tio

su

neq

ual

1an

dfo

un

dth

efo

llow

ing

cau

ses:

By

dis

per

sio

no

fth

esm

alle

rvo

lum

efl

ow

(ph

ase

rati

o≪

1),

stro

ng

erb

ack

mix

ing

of

dro

ple

tsb

yth

eco

nti

nu

ou

sp

has

ew

ill

occ

ur,

lead

ing

toa

bro

ader

dro

psi

zed

istr

ibu

tio

n.

By

dis

per

sio

no

fth

ela

rger

vo

lum

efl

ow

(ph

ase

rati

o≫

1),

the

wak

eb

ehin

dth

ed

rop

sca

use

sre

mar

kab

leb

ack

-m

ixin

go

fco

nti

nu

ou

sp

has

e.T

hes

ep

hen

om

ena

hav

eto

be

taken

into

acco

un

tb

yan

adeq

uat

eca

lcu

lati

on

via

dro

pp

op

ula

tio

nb

alan

ces.

G.

Wagn

er

[58]

inves

tigat

edth

efl

uid

dy-

nam

ics

of

pu

lsed

siev

etr

ayan

dK

uh

ni

rota

tin

gex

trac

tors

usi

ng

liq

uid

syst

ems

wit

hv

isco

siti

esu

pto

50

mP

a·s

,m

ixed

fro

mp

araf

fin

oil

and

n-h

exan

eas

org

anic

phas

ean

dof

gly

cero

lan

dw

ater

asaq

ueo

us

ph

ase.

I.W

agn

er

[77

]co

n-

tinued

the

work

wit

hm

ass

tran

sfer

inves

tiga-

tio

ns

usi

ng

the

syst

emtr

idec

ano

las

dro

pp

has

e(η

=4

2m

Pa·s

),w

ater

,an

dp

rop

ano

l.T

he

exp

er-

imen

tssh

ow

edth

atth

em

ean

Sau

ter

dro

pd

i-am

eter

incr

ease

sw

ith

incr

easi

ng

dro

pv

isco

sity

;h

old

up

isd

ecre

ased

,w

hil

eth

efl

oo

din

gcu

rve

issh

ifte

dto

hig

her

thro

ug

hp

uts

.In

case

the

36

Liq

uid

–Liq

uid

Extr

action

con

tin

uo

us

ph

ase

isth

em

ore

vis

cou

so

ne,

the

dro

psw

arm

con

tain

sa

larg

erfr

acti

on

of

smal

ld

rop

lets

cau

sin

gin

crea

sed

dro

ple

ten

trai

nm

ent

by

the

con

tin

uo

us

ph

ase.

Inst

irre

dco

lum

ns,

the

dro

psi

zeca

nb

ein

flu

ence

din

ab

road

erra

ng

eth

anin

pu

lsed

colu

mn

s;y

et,m

ore

ener

gy

wil

lb

ere

qu

ired

for

ace

rtai

nd

rop

dis

per

sio

n.In

ten

sive

stir

rers

asin

Ku

hn

ian

dQ

VF

extr

acto

rssh

ou

ldb

ep

refe

rred

tost

irre

rsin

RD

Cex

trac

tors

.In

the

case

of

am

ore

vis

cou

sco

nti

nu

ou

sp

has

e,th

ed

rop

dis

per

sio

nis

nea

rly

ind

epen

den

to

fd

rop

vis

cosi

tyan

dis

har

dly

infl

uen

ced

by

the

rota

tin

go

rp

uls

atin

gin

tern

als.

Her

e,lo

wer

in-

ten

sity

dis

per

sers

are

pre

fera

ble

,su

chas

RD

Cex

trac

tors

.T

he

mas

str

ansf

erto

dro

ps

isd

isti

nct

lyd

e-cr

ease

db

yin

crea

sin

gd

rop

vis

cosi

ty,d

evel

op

ing

tow

ard

sth

est

ate

of

tran

sfer

tori

gid

sph

eres

,an

dd

epen

ds

on

the

con

tact

tim

e.It

can

be

imp

roved

by

suit

able

inte

rnal

san

db

ysu

pp

lyo

fen

erg

y.

4.

Ph

ase

-Sep

ara

tion

Eq

uip

men

t

4.1

.G

rav

ity

Set

tler

sw

ith

ou

tIn

sert

s

Eac

hex

trac

tio

nst

age

con

sist

so

ftw

ost

eps:

(1)

dis

per

sin

gan

d(2

)p

has

ese

par

atio

nb

yco

ales

-ce

nce

of

dro

ps,

thu

sg

ener

atin

ga

ho

mo

gen

eou

sla

yer

of

dro

pp

has

e.F

igu

re3

9A

show

sa

ver

tica

lse

ttle

rat

the

top

of

aco

lum

nfo

rth

eca

seth

atth

ed

rop

ph

ase

has

alo

wer

den

sity

than

the

con

tin

-uous

phas

e.T

he

dro

ps

rise

agai

nst

the

sinkin

gco

nti

nu

ou

sli

qu

idan

dar

eb

lock

edb

yth

eu

pp

erle

vel

of

the

con

tin

uo

us

ph

ase,

wh

ich

isth

ep

rin

-ci

pal

inte

rfac

e.T

her

e,co

ales

cen

ceo

fth

ed

is-

per

sed

ph

ase

wil

lo

ccu

rb

oth

bet

wee

nad

jace

nt

dro

ps

and

atth

ep

rin

cip

alin

terf

ace.

Th

eco

a-le

sced

dro

pp

has

ele

aves

the

extr

acto

rat

the

top

of

the

colu

mn

.In

ah

ori

zon

tal

sett

ler,

assh

ow

nin

Fig

-u

re3

9B

,bo

thp

has

esfl

ow

inth

esa

me

dir

ecti

on

.D

rop

so

fli

gh

ter

dis

per

sed

ph

ase

rise

toth

ein

ter-

face

wh

ere

they

coal

esce

tofo

rma

ho

mo

gen

eou

sla

yer

.In

the

low

erp

art

of

the

sett

ler

ala

yer

of

the

con

tin

uo

us

ph

ase

rem

ain

s,g

row

ing

infl

ow

dir

ecti

on

du

eto

dec

reas

ing

dro

pn

um

ber

s.T

he

wed

ge-

shap

edzo

ne

of

dis

per

sio

nsh

ou

lden

db

e-fo

reth

ep

lace

men

to

fp

has

eo

utl

ets.

As

the

accu

mu

lati

on

of

imp

uri

ties

inte

ch-

nic

alli

qu

idsy

stem

sch

ang

esim

po

rtan

tp

rop

er-

ties

such

asv

isco

sity

and

surf

ace

ten

sio

n,an

ex-

clu

sivel

yth

eore

tica

lm

od

elin

g,as

dev

elo

ped

by

man

yau

tho

rs(s

eefo

rin

stan

ce[8

0])

,is

insu

ffi-

cien

t.H

ow

ever

,th

ele

ng

tho

fa

ho

rizo

nta

lse

ttle

rca

nb

ees

tim

ated

by

aco

mb

ined

pro

ced

ure

of

calc

ula

tio

ns

and

sim

ple

and

chea

pb

atch

sett

lin

gex

per

imen

ts[7

9].

Th

eca

lcu

lati

on

isb

ased

on

am

odel

of

the

physi

cal

pro

cess

esin

ase

ttle

r,w

hil

eex

per

imen

tssu

pp

lyo

ne

emp

iric

alp

aram

-et

erto

incl

ud

esu

rfac

ep

hen

om

ena

that

cou

ldn

ot

be

mo

del

edso

far

(see

Fig

s.4

0an

d4

1).

Ag

lass

cyli

nd

eras

show

nin

Fig

ure

40

A,

fill

edw

ith

abo

ut

1L

of

the

ori

gin

alli

qu

id–

liq

-u

idsy

stem

,is

vig

oro

usl

ysh

aken

for

1/2

to1

min

.Aft

erp

laci

ng

itin

anu

pri

gh

tp

osi

tio

n,t

he

hei

gh

tso

fse

dim

enta

tio

nan

dco

ales

cen

cefr

on

tsar

em

easu

red

ind

epen

den

ceo

fti

me

assh

ow

nin

Fig

ure

40

Bfo

rd

rop

sb

ein

gli

gh

ter

than

the

con

tin

uo

us

ph

ase.

Th

ed

rop

sar

eb

anked

up

ina

den

sela

yer

ifse

dim

enta

tio

nis

fast

erth

anth

ed

rop

coal

esce

nce

.T

he

curv

eso

fse

dim

enta

tio

nan

dco

ales

cen

cem

eetea

cho

ther

atti

me

t ew

hen

all

dro

ps

are

coal

esce

d.

Fo

ra

suffi

cien

tre

pro

-d

uci

bil

ity

of

mea

sure

men

tsit

sho

uld

be

mad

esu

reth

atth

eg

lass

flas

kis

was

hed

wit

hd

eio

n-

ized

wat

er,

that

the

dis

trib

uti

on

of

dro

psi

zes

isn

arro

wan

dth

ete

mp

erat

ure

so

fth

eli

qu

id–

liq

-u

idsy

stem

inth

eg

lass

cyli

nd

eran

dth

eco

nti

nu

-o

us

sett

ler

are

equ

al[7

8].

Fig

ure

37

Csh

ow

sth

eh

eig

htH

of

the

wed

ge-

shap

edzo

ne

bet

wee

nth

ecu

rves

of

sed

imen

tati

on

and

coal

esce

nce

.T

he

con

cep

to

fse

ttle

rd

imen

sio

nin

gis

show

nin

Fig

ure

41

.A

lleq

uat

ion

sm

enti

on

edin

the

fol-

low

ing

are

giv

enin

[79

].S

ettl

erd

imen

sio

nin

gst

arts

wit

hev

alu

atio

no

fse

ttli

ng

exp

erim

ents

ac-

cord

ing

toF

igu

re4

1A

.T

he

lin

ear

curv

eo

fse

d-

imen

tati

on

sup

pli

esth

evel

oci

tyo

fse

dim

enta

-ti

on

;a

mo

del

of

dro

psw

arm

sed

imen

tati

on

sup

-p

lies

the

dia

met

ero

fth

est

arti

ng

dro

psw

arm

[66

].T

he

thic

kn

ess

of

the

den

sela

yer

of

dro

ps

foll

ow

sfr

om

ab

alan

ceo

fse

dim

enti

ng

and

co-

ales

cin

gd

rop

sin

tim

est

eps.

Th

en

ext

stag

eis

calc

ula

tio

no

fd

rop

def

orm

atio

nin

ver

tica

lst

eps

[80

].T

his

serv

esto

calc

ula

teco

ales

cen

ceti

mes

bet

wee

nd

rop

san

db

etw

een

dro

ps

and

thei

rh

om

op

has

e,th

efo

rmer

tod

eter

min

eth

ed

rop

gro

wth

,th

ela

tter

toca

lcu

late

the

dro

ph

o-

mo

ph

ase

form

edb

yco

ales

cen

ce[8

0].

Th

eco

a-le

scen

cem

od

elco

nta

ins

afi

ttin

gp

aram

eter

Fp

tofi

tth

eca

lcu

late

dan

dm

easu

red

coal

esce

nce

curv

ein

Fig

ure

41

B.

Th

isp

aram

eter

isth

eli

nk

bet

wee

nth

ese

ttli

ng

exp

erim

ent

and

the

sett

ler

Page 19: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

37

Fig

ure

39.

Ver

tica

l(A

)an

dhori

zonta

l(B

)gra

vit

yse

ttle

rsfo

rdro

pse

par

atio

nfr

om

aco

nti

nuous

liquid

Fig

ure

40.

Exper

imen

tson

bat

chse

ttli

ng

dim

ensi

on

ing

;F

pca

nb

eu

sed

for

the

sett

ler

cal-

cula

tio

n,

giv

enin

Fig

ure

41

B.

Th

ese

ttle

rn

eed

san

inle

tle

ng

thL

inw

hic

hca

nb

eca

lcu

late

db

ya

mo

del

equ

atio

nin

dep

en-

den

ceo

nse

ttle

rd

iam

eter

,o

per

atio

np

aram

eter

s,an

dth

em

ean

dro

psi

zeat

the

sett

lerin

let,

com

ing

fro

mth

eex

trac

tor

ou

tlet

.Fo

rca

lcu

lati

on

of

coa-

lesc

ence

inth

ed

ense

dro

pla

yer

the

sam

eeq

ua-

tio

ns

that

wer

em

od

eled

for

the

sett

lin

gex

per

i-m

ent

can

be

app

lied

usi

ng

the

fitt

ing

par

amet

erF

pd

eriv

edfr

om

thes

eex

per

imen

ts.

Th

ere

sult

isth

eg

eom

etry

of

the

wed

ge

of

dis

per

sio

n,i.

e.,

its

hei

gh

tan

dle

ng

th,w

hic

hh

asto

be

taken

into

acco

un

tfo

rd

imen

sio

nin

gth

ese

ttle

r.T

his

com

bin

edex

per

imen

tal

and

theo

reti

cal

pro

ced

ure

yie

lds

go

od

resu

lts

alth

ou

gh

the

dro

pd

istr

ibu

tio

ns

inth

ese

ttli

ng

exp

erim

ent

and

the

real

sett

ler

are

no

tth

esa

me.

Th

eex

ten

sive

equ

a-ti

on

syst

emn

eed

sco

mp

ute

rai

ded

solv

ing

.A

com

pu

ter

pro

gra

mis

off

ered

by

[81

].A

sim

pli

-fi

edm

eth

od

isg

iven

in[7

9].

4.2

.S

ettl

ers

wit

hC

oa

lesc

ing

Aid

s

Gra

vit

yse

ttle

rsar

eo

ften

equ

ipp

edw

ith

coal

esc-

ing

aid

sto

fita

sett

ler

tosp

ecia

lco

nd

itio

ns

of

the

liq

uid

syst

emo

ro

fth

eo

per

atio

nal

beh

avio

r.In

-d

ust

rial

lyp

roven

coal

esci

ng

aid

sar

ein

clin

edo

rco

rrugat

edpla

tes,

fixed

bed

sof

smal

lpac

kin

gs,

fib

erb

eds,

po

rou

ssi

nte

red

mat

eria

ls,an

dm

em-

bra

nes

.In

som

eca

ses,

wh

enth

ed

rop

size

sto

be

sett

led

are

smal

ler

than

mo

rif

surf

acta

nts

ren

der

the

sett

lin

gm

ore

dif

ficu

lt,ce

ntr

ifu

ges

[6,

Ch

ap.8

]o

rel

ectr

ical

fiel

ds

mu

stb

eap

pli

ed[8

2].

Th

em

ost

imp

ort

antco

ales

cin

gai

ds

are

incl

ined

pac

kag

esof

pla

inor

corr

ugat

edpla

tes

and

fiber

bed

filt

ers.

38

Liq

uid

–Liq

uid

Extr

action

Fig

ure

41.

Dim

ensi

on

ing

aco

nti

nu

ou

sse

ttle

r[7

9]

A)

Eval

uat

ion

of

sett

lin

gex

per

imen

ts;

B)

Fit

tin

go

fm

easu

red

and

calc

ula

ted

curv

e

Incl

ined

Pla

tes.

Fig

ure

42

show

so

ne

po

ssi-

ble

arra

ng

emen

to

fin

clin

edp

late

sin

ah

ori

zon

-ta

lse

ttle

r.O

ther

pla

teco

nfi

gu

rati

on

sar

ep

oss

i-b

le.

Inan

yca

se,

the

feed

has

tob

ed

istr

ibu

ted

by

asi

eve

pla

teat

the

sett

ler

entr

yover

the

cro

ss-s

ecti

on

alar

ea,

fill

edw

ith

incl

ined

pla

tes.

Th

ep

late

ssh

ort

enth

ese

dim

enta

tio

nd

ista

nce

of

dro

ps

and

pro

vid

ea

larg

erin

terf

acia

lare

afo

rth

eco

ales

cen

ce.

Th

ed

rop

sco

ales

cin

gat

the

pla

tes

form

tric

kli

ng

film

sw

hic

hfl

ow

off

toth

eh

or-

izo

nta

l,p

rin

cip

lein

terf

ace

du

eto

ahy

dro

stat

icp

ress

ure

dif

fere

nce

.Ap

late

mat

eria

lwet

tab

leb

yth

ed

rop

ph

ase

isa

pre

req

uis

ite.

Sev

eral

scie

n-

tifi

cin

ves

tigat

ions

and

exper

imen

tsw

ith

liquid

syst

ems

of

aw

ide

ran

ge

of

pro

per

ties

wer

em

ade

duri

ng

the

1970s

and

1980s

on

the

hydro

dynam

-ic

so

fin

clin

edfi

lms

and

the

coal

esce

nce

ofd

rop

s

atth

efi

lmsu

rfac

e,th

ese

are

sum

mar

ized

in[8

3–

86

].T

he

mai

nre

sult

sar

e:

1)

Th

inla

min

arfi

lms

sho

uld

flow

on

the

pla

tes,

bec

ause

the

coal

esce

nce

of

dro

ps

isp

rom

ote

db

yth

esh

ear

stre

sso

ffi

lmfl

ow

nea

rth

ep

late

;th

ela

rger

the

vo

lum

efl

ow

of

cocu

rren

tco

nti

nu

ou

sp

has

e,th

esm

alle

rth

efi

lmth

ick

nes

san

dth

eb

ette

rth

eco

ales

-ce

nce

.2

)T

he

pla

tesh

ou

ldb

ew

etta

ble

by

the

dro

pp

has

e(a

dvan

cin

gco

nta

ctan

gle

<7

0◦,

re-

ced

ing

con

tact

ang

le>

15◦).

3)

Th

ed

rop

swar

mh

asto

be

dis

trib

ute

deq

ual

lyover

the

wid

tho

fp

late

s.4

)C

on

stru

ctio

ns

that

can

thin

the

tric

kli

ng

film

incr

ease

the

sett

ler

per

form

ance

.

Page 20: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

39

5)

Sh

ort

len

gth

so

fp

late

so

fab

ou

t4

00

mm

are

suffi

cien

tfo

rco

ales

cen

ceo

fd

rop

sri

din

go

nth

efi

lm.

6)

Th

ew

idth

bp

of

ap

late

can

be

calc

ula

ted

by

the

emp

iric

aleq

uat

ion

of

the

Rey

no

lds

nu

mb

ero

ftr

ick

lin

gfi

lm

Re f≤

80K

0.1

9L

,d

b p=

0.0

3Vd

(Re f

kvd)3

/2

[

∆gsi

ηd

]

wit

hth

eli

qu

idn

um

ber

of

tric

kli

ng

film

KL

,d=

σ3d

gη4 d

d

wh

ereα

isth

ep

late

incl

inat

ion

,Vd,1

=V

d/n

the

vo

lum

efl

ow

of

dis

per

sed

ph

ase

on

ap

late

,an

dn

the

nu

mb

ero

fp

late

s.7

)T

he

op

tim

um

of

pla

tein

clin

atio

nis

wit

hin

the

ran

ge

10◦<

α<

15◦.

8)

Th

ed

ista

nce

of

adja

cen

tp

late

ssh

ou

ldn

ot

be

smal

ler

than

30

to4

0m

min

ord

ern

otto

dis

turb

film

flow

and

dro

pco

ales

cen

ce.

9)

Th

etr

ick

lin

gfi

lmco

nti

nu

ou

sly

carr

ies

sur-

fact

ants

toth

eo

utfl

ow

of

ap

late

and

thu

sp

reven

tsth

eirac

cum

ula

tio

n.T

her

efo

resu

r-fa

ctan

tsh

ard

lyin

flu

ence

coal

esce

nce

and

sett

lin

gp

erfo

rman

ceu

pto

med

ium

flow

rate

so

fd

rop

ph

ase.

10

)U

nd

erce

rtai

nco

nd

itio

ns,

the

dro

pco

a-le

scen

cele

aves

ver

ysm

all

dro

ple

ts,

so-

call

edse

con

dar

yd

rop

s,d

ue

top

arti

alco

a-le

scen

ce,w

hic

hg

ener

ate

ad

rop

leten

trai

n-

men

tatt

he

sett

ler

exit

.Its

occ

urr

ence

isp

ri-

mar

ily

aq

ues

tio

no

fli

qu

ids

invo

lved

,i.

e.,

thei

rv

isco

sity

rati

o[8

6].

Th

eco

ales

cen

ceti

me

of

seco

nd

ary

dro

ps

issi

gn

ifica

ntl

yh

igh

erth

anth

ato

fp

rim

ary

dro

ps,

du

eto

inte

rfac

ial

effe

cts.

Set

tlin

go

fse

con

dar

yd

rop

sre

qu

ires

oth

erco

ales

cers

,fo

rin

stan

cem

emb

ran

eco

ales

cers

or

cen

trif

ug

es.

Fib

erb

edfi

lter

sar

ebu

ilt

fro

msh

ort

fib

ers

stu

ffed

tore

ctan

gu

lar

mat

so

rto

dis

ks

of

15

to2

5m

mth

ick

nes

s,h

eld

ina

suit

able

sup

po

rt,

or

fro

mfi

ber

flee

ces

assh

ow

nin

Fig

ure

43

.T

hey

hav

ea

defi

nit

e,la

rge

vo

idag

eo

fab

ou

t9

5%

,nev

erth

eles

sth

eyar

ese

nsi

tive

toso

lid

dir

tp

arti

cles

inth

eli

qu

id.T

he

dro

ple

tsco

up

leto

the

fib

ers

wh

ile

flow

ing

thro

ug

hth

efi

ber

bed

,su

c-ce

edin

gd

rop

sco

ales

cew

ith

them

and

enla

rge

the

size

of

adh

erin

gd

rop

su

nti

lth

eli

qu

idfl

ow

pu

lls

them

ou

to

fth

eb

edd

ue

toin

crea

sin

gfl

ow

resi

stan

ce.A

fib

erb

edis

able

toen

larg

eth

esi

zes

of

inco

min

gd

rop

sat

leas

tb

yo

ne

ord

ero

fm

ag-

nit

ud

eso

that

they

can

coal

esce

ina

sub

seq

uen

tse

ttle

rw

ith

thei

rh

om

op

has

e.F

iber

bed

filt

ers

are

rest

rict

edto

dro

pco

nce

ntr

atio

ns<

10

vo

l%to

avo

idre

dis

per

sio

n.

Rebelein

[87

],[8

8]

and

Magie

ra

[89

],[9

0]

defi

ned

heu

rist

icru

les

forth

ed

esig

no

ffi

ber

bed

so

nth

eb

asis

of

care

fulex

per

imen

tsw

ith

ab

road

var

iati

on

of

par

amet

ers

of

infl

uen

ce:

1)

Fib

erm

ater

ials

asg

lass

or

stai

nle

ssst

eel

wit

hh

igh

ener

get

icsu

rfac

esp

rov

ide

dif

fer-

ent

inte

ract

ion

site

s(e

.g.,

hydro

gen

bonds

and

ion

–d

ipo

lein

tera

ctio

n)

for

the

liq

uid

and

imp

rove

the

fib

erb

edp

erfo

rman

ceco

m-

par

edto

mat

eria

lsw

ith

low

ener

get

icsu

r-fa

ces

asfo

rin

stan

cete

flo

n.

Hig

hen

erg

etic

surf

aces

imp

rove

the

wet

tin

gp

rop

erti

eso

fth

efi

ber

s.2

)T

he

dro

pen

larg

emen

tin

afi

ber

bed

de-

crea

ses

wit

hin

crea

sin

gfl

ow

rate

,i.

e.,

wit

hsu

per

fici

alvel

oci

ties

>1

cm/s

.3

)S

mal

lfi

ber

dia

met

ers

of

abo

ut

15

µm

are

fa-

vo

rab

le.

4)

Th

eb

edd

epth

req

uir

edfo

rco

ales

cen

cein

-cr

ease

sw

ith

the

fib

erd

iam

eter

.5

)T

he

con

cen

trat

ion

of

dro

ple

tsin

the

inco

m-

ing

liq

uid

har

dly

infl

uen

ces

the

bed

per

for-

man

ce.

6)

Bes

tef

fici

ency

mea

ns

ase

par

atio

no

fab

ou

t9

5%

of

inco

min

gd

rop

s.7

)T

he

larg

erth

esu

rfac

ete

nsi

on

of

the

liq

-u

idsy

stem

,th

eb

ette

rth

ese

par

atio

np

erfo

r-m

ance

.8

)S

mal

lest

dro

psi

zes

that

can

be

sep

arat

edar

eab

ou

t1

m.

9)

Pre

sen

ceo

fsu

rfac

tan

tsan

dm

ud

and

ah

igh

erv

isco

sity

of

the

con

tin

uo

us

ph

ase

red

uce

the

sep

arat

ion

per

form

ance

,th

ev

isco

sity

of

the

dro

pp

has

eh

asn

oin

flu

ence

wit

hin

50

and

50

00

mP

a·s

.

All

atte

mp

tsto

calc

ula

teth

eb

edp

erfo

rman

cein

advan

cev

iafi

lter

coef

fici

ents

wer

efr

uit

less

[87

–9

0].

Magie

ra

dev

elo

ped

am

ath

emat

ical

model

of

physi

calm

echan

ism

sin

side

afi

ber

bed

and

was

able

tosi

mu

late

the

bed

beh

avio

ran

dd

rop

enla

rgem

ent

by

intr

od

uct

ion

of

two

exp

er-

imen

tal

fitt

ing

par

amet

ers.

Th

eref

ore

,a

reli

able

dim

ensi

on

ing

of

fib

erb

eds

nee

ds

exp

erim

ents

40

Liq

uid

–Liq

uid

Extr

action

Fig

ure

42.

Hori

zonta

lg

rav

ity

sett

ler

wit

htw

oin

clin

edp

ack

ages

of

pla

ne,

par

alle

lp

late

s.T

he

hei

gh

to

fp

rin

cip

alin

terf

ace

isbes

tsi

tuat

ed,w

hen

bo

thp

has

esh

ave

the

sam

eex

itvel

oci

ty

Fig

ure

43.

Com

bin

edfi

ber

bed

coal

esce

ran

dg

rav

ity

sett

ler

wit

hth

eli

qu

idd

isp

ersi

on

wh

ich

isto

be

sep

a-ra

ted

.

Fig

ure

44.

Mem

bra

ne

coal

esce

r[9

1]

Mem

bra

ne

Co

ale

scen

ce.

An

ewan

dver

yp

rom

isin

gm

eth

od

tose

par

ate

fin

ed

rop

lets

dow

nto

mfr

om

emu

lsio

ns,

stab

iliz

edb

ysu

rfac

-ta

nts

,w

asdis

cover

edan

din

ves

tigat

edby

Hoff-

man

n[9

1]

(Fig

.44

).M

emb

ran

eco

ales

cers

are

app

lica

ble

ina

bro

adra

ng

eo

fvo

lum

eco

nce

ntr

atio

ns

dow

nto

alo

wer

conce

ntr

atio

nli

mit

of

the

org

anic

phas

e(0

.1vo

l%).

Ath

in,

hydro

phobic

,st

retc

hed

mem

bra

ne,

for

inst

ance

po

lyte

trafl

uo

roet

hy

len

e(P

TF

E),

hel

din

pla

ceb

ya

sup

po

rt,

isp

erm

e-at

edb

ytw

o-p

has

efl

ow

of

emu

lsio

n.

Th

eem

ul-

sio

nle

aves

the

mem

bra

ne

asa

liq

uid

foam

wit

hla

rge

oil

do

mai

ns

wh

ich

wil

lim

med

iate

lyco

-al

esce

atth

ep

rin

cip

lein

terf

ace

ina

succ

eed

-in

gse

ttle

r.A

sup

erfi

cial

vel

oci

tyth

rou

gh

the

mem

bra

ne

isp

oss

ible

wit

hin

the

ran

ge

of

0.1

to1

9cm

/s,t

he

pre

ssu

red

rop

isco

mp

arab

lew

ith

that

infi

ber

bed

s.T

he

mai

nad

van

tag

esar

eh

ug

ese

par

atio

np

erfo

rman

ces

of

abo

ut9

8%

,in

com

-b

inat

ion

wit

ha

larg

era

ng

ein

thro

ug

hp

ut;

the

Page 21: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

41

abil

ity

tose

par

ate

dro

ple

tso

ne

ord

ero

fm

ag-

nit

ud

esm

alle

rth

anin

fib

erb

eds;

and

the

in-

sensi

tivit

yag

ainst

hydro

phobic

surf

acta

nts

.H

y-

dro

ph

ilic

surf

acta

nts

are

wit

ho

ut

infl

uen

ce,

too

,if

thei

ram

ou

nt

iscl

earl

ylo

wer

than

the

crit

ical

mic

elle

con

cen

trat

ion

.

Sel

ecti

on

of

Ap

pro

pri

ate

Set

tler

.M

ost

im-

po

rtan

tan

dth

efi

rst

step

inse

lect

ion

of

ase

ttle

ris

aca

refu

lan

aly

sis

of

sep

arat

ion

pro

ble

ms

[78

],[9

2].

Th

efl

ow

shee

to

fth

eco

mp

lete

pro

cess

can

giv

eh

ints

on

ori

gin

and

kin

do

fth

ed

isp

ersi

on

tob

ese

par

ated

.S

om

etim

esth

ep

rece

din

gst

eps

cou

ldb

eal

tere

din

ord

erto

sim

pli

fyth

ep

has

ese

par

atio

np

rob

lem

.Mea

sure

men

tso

fp

rop

erti

eso

fth

eli

qu

idsy

stem

and

sett

lin

gex

per

imen

tsin

agla

sscy

linder

show

,if

and

why

aphas

ese

par

a-ti

on

can

be

pro

ble

mat

ic.D

rop

size

ssm

alle

rth

an1

00

µm

nee

dsu

itab

leco

ales

cin

gai

ds

wh

ich

are

sup

po

sed

tob

ew

ell

wet

tab

leb

yth

ed

rop

ph

ase.

Wh

enth

ed

rop

sett

lin

gin

ag

lass

cyli

nd

eris

fast

,bu

tth

eli

qu

ids

app

ear

clo

ud

y,th

isin

dic

ates

par

-ti

alco

ales

cen

ce,

resu

ltin

gin

ver

yfi

ne

dro

ps,

soth

ata

fib

erb

edo

ra

mem

bra

ne

coal

esce

rw

ill

be

nec

essa

ry.

Th

ep

rese

nce

of

soli

dp

arti

cles

and

mu

dre

-q

uir

esfi

lter

sb

efo

reth

ese

ttle

r.T

he

wet

tin

gb

ehav

ior

of

coal

esci

ng

aid

sca

nsi

gn

ifica

ntl

ych

ang

eth

eo

per

atio

no

fth

ep

roce

ss.T

his

sho

uld

be

acco

un

ted

for

inth

ep

rocc

es.

Th

ep

has

era

-ti

oca

nb

ech

ang

edb

yre

cycl

ing

of

on

ep

has

eto

the

sett

ler.

By

this

,th

ety

pe

of

dis

per

sio

nca

nb

ein

ver

ted.

Inca

seth

eorg

anic

phas

ehas

ahig

her

vis

cosi

tyth

anth

ew

ater

ph

ase,

ano

/wd

isp

ersi

on

sep

arat

esm

uch

bet

ter

than

aw

/od

isp

ersi

on

,an

dv

ice

ver

sa.

5.

Liq

uid

–L

iqu

idE

xtr

act

ion

Pro

cess

es

5.1

.G

ener

al

Th

eq

ual

ity

of

the

raffi

na

tein

liq

uid

–li

qu

idex

-tr

acti

on

can

be

con

tro

lled

easi

lyb

ych

ang

ing

the

rati

oo

fso

lven

tto

feed

and

the

extr

acti

on

tem

-p

erat

ure

.T

he

qu

alit

yo

fth

eex

tra

ctis

gover

ned

on

lyb

yth

eco

nd

itio

ns

of

feed

loca

tio

nan

dn

od

irec

tco

ntr

ol

isp

oss

ible

.T

his

ises

pec

iall

ytr

ue

bec

ause

mo

stex

trac

-ti

on

sar

eca

rrie

do

ut

ina

clo

sed

syst

emto

min

-im

ize

solv

ent

req

uir

emen

ts.

Insu

cha

syst

em,

a

max

imu

mex

trac

tp

uri

tyis

ob

tain

able

and

som

eco

mp

on

ents

that

sho

uld

end

up

inth

era

ffin

ate

leav

ew

ith

the

extr

act.

Ad

dit

ion

alst

eps

are,

ther

efo

re,

req

uir

edto

enh

ance

extr

act

pu

rity

and

thu

sra

ffin

ate

yie

ld.

Ifth

eex

trac

tis

the

pro

du

ctd

esir

ed,

imp

rov

ing

extr

act

pu

rity

isth

em

ost

imp

ort

ant

–in

fact

,th

eo

nly

–o

bje

ctiv

e.D

iffe

ren

tso

luti

on

sto

this

pro

ble

mar

eap

pli

edin

com

mer

cial

op

erat

ion

.

Ch

an

ge

inT

emp

era

ture

.E

xtr

actp

uri

tyca

nb

ein

crea

sed

by

coo

lin

gth

eex

trac

tfr

om

the

mai

nsy

stem

and

add

ing

on

em

ore

stag

e(s

eeF

ig.4

5A

).In

the

tria

ng

ula

rd

iag

ram

,th

ism

ean

sth

atth

eb

ino

dal

curv

eis

chan

ged

fro

ma

tob

(Fig

.45

B).

Bec

ause

the

com

po

siti

on

of

the

firs

tex

trac

tis

now

insi

de

bin

od

alcu

rve

b,

itse

par

ates

ina

sett

ler

bin

ap

ure

rfi

nal

extr

actp

has

ean

da

smal

lam

ou

nt

of

inte

rmed

iate

raffi

nat

ep

has

e.T

he

lat-

ter

isre

turn

edto

the

mai

nex

trac

tio

nsy

stem

.T

he

sele

ctiv

ity

of

sep

arat

ion

inth

ead

dit

ion

alst

age

isn

ot

ver

yg

reat

bec

ause

the

load

ing

of

the

firs

tex

trac

tp

has

eis

rath

erh

igh

and

sep

ara-

tio

nta

kes

pla

cen

ear

the

pla

itp

oin

t.T

his

syst

emca

nb

eu

sed

wh

enth

em

ain

syst

emis

op

erat

edat

hig

hte

mp

erat

ure

for

oth

erre

aso

ns

or

wh

enan

incr

ease

inex

trac

tp

uri

tyan

dth

ere

sult

ant

incr

ease

inra

ffin

ate

yie

ldar

ed

esir

able

.

Ad

dit

ion

of

Wa

ter.

Th

ead

dit

ion

of

wat

erat

or

bel

ow

the

feed

po

int

gen

eral

lych

ang

esth

esy

stem

fro

ma

clo

sed

toan

op

eno

ne

(see

Sec

-ti

on

2.1

.1.)

.In

this

way

,ex

trac

tp

uri

tyca

nb

ein

crea

sed

toth

ere

qu

ired

level

.W

ater

isso

lub

le,

atle

ast

toso

me

exte

nt,

inm

ost

po

lar

solv

ents

and

ther

efo

rele

aves

the

syst

emw

ith

the

fin

alex

trac

tp

has

e.In

this

way

,n

ou

nw

ante

din

flu

-en

ceis

exer

ted

on

the

mai

nex

trac

tio

nsy

stem

.H

ow

ever

,b

ecau

sew

ater

mu

stb

ese

par

ated

fro

mth

eso

lven

tb

yd

isti

llat

ion

bef

ore

its

rein

-tr

od

uct

ion

inth

em

ain

extr

acto

r,th

eh

eatr

equ

ire-

men

tsar

eh

igh

.A

dd

itio

no

fw

ater

is,

ther

efo

re,

not

regar

ded

asa

gen

eral

lyat

trac

tive

solu

tion.

Als

o,

wat

erca

no

nly

be

add

edw

hen

its

bo

ilin

gp

oin

tis

mu

chlo

wer

than

tho

seo

fth

eso

lven

tan

dth

efe

edst

ock

.

Use

of

aC

ou

nte

rso

lven

t.A

ssh

ow

nin

Fig

-u

re4

6,a

seco

nd

solv

entca

nb

efe

din

too

ne

end

of

the

extr

acti

on

syst

em,o

nth

eo

pp

osi

tesi

de

of

42

Liq

uid

–Liq

uid

Extr

action

Fig

ure

45.

Use

of

coo

lin

gst

age

A)

Pro

cess

flow

schem

e:a)

Ex

trac

tor;

b)

Set

tler

B)

Tri

angula

rdia

gra

m:

a)B

ino

dal

curv

eat

hig

her

tem

per

atu

re;

b)

Bin

od

alcu

rve

atlo

wer

tem

per

atu

re

the

solv

ent

entr

yp

oin

t.T

he

feed

inth

isca

seis

intr

od

uce

dso

mew

her

ein

the

mid

dle

of

the

sys-

tem

.

Fig

ure

46.

Extr

acto

rfo

rse

par

atio

nu

sin

ga

cou

nte

rso

lven

t(a

)E

xtr

acto

r

Th

eco

un

ters

olv

ent

sho

uld

be

on

lysl

igh

tly

solu

ble

inth

eso

lven

tan

d,th

eref

ore

isg

ener

ally

sim

ilar

inch

emic

alst

ruct

ure

toth

ekey

com

-p

on

ent

of

the

raffi

nat

ep

has

e.T

he

bo

ilin

gp

oin

to

fth

eco

un

ters

olv

ent

sho

uld

be

such

that

itca

nea

sily

be

sep

arat

edb

yd

isti

llat

ion

fro

mth

eso

l-ven

tas

wel

las

fro

mth

era

ffin

ate

and

the

extr

act

(i.e

.,ei

ther

am

uch

low

ero

ra

mu

chh

igh

erb

oil

-in

gp

oin

t).B

ecau

seth

eco

un

ters

olv

ent

do

esn

ot

con

tain

any

raffi

nat

eco

mp

on

ents

wh

enit

ente

rs,

itca

nw

ash

ou

tth

era

ffin

ate

com

po

nen

tsin

the

solv

ent

atth

efe

edp

oin

t.A

dd

itio

nal

ly,

som

eex

trac

tco

mp

on

ents

are

was

hed

bac

kb

yth

eco

un

ters

olv

ent,

thu

sin

crea

s-in

gth

elo

adin

the

top

sect

ion

.In

this

way

,aver

yp

ure

fin

alex

trac

tcan

be

pro

du

ced

,dep

end

ing

on

the

rati

oo

fco

un

ters

olv

ent

tofe

edu

sed

.A

dis

advan

tag

eo

fth

issy

stem

isth

atth

eco

un

-te

rso

lven

ten

ters

the

top

sect

ion

.C

on

seq

uen

tly,

the

ph

ase

rati

oo

fB

-ric

hto

A-r

ich

ph

ase

isre

-d

uce

d,r

esu

ltin

gin

ale

ssp

ure

raffi

nat

e(t

his

also

mea

ns

alo

wer

yie

ldo

fex

trac

t).T

ore

sto

rera

ffi-

nat

ep

uri

ty,m

ore

B-r

ich

ph

ase

mu

stb

eap

pli

ed.

Su

cha

syst

emis

thu

sco

stly

and

sen

siti

ve

toch

ang

esin

feed

com

po

siti

on

,so

lven

t-to

-fee

dra

-ti

o,

and

rati

oo

fco

un

ters

olv

ent

tofe

ed.

So

me

imp

rovem

ent

can

be

ob

tain

edb

yca

r-ry

ing

ou

tth

eex

trac

tio

nin

two

par

ts(F

ig.4

7).

Inth

efi

rst

extr

acto

r(a

),th

efe

edis

extr

acte

dw

ith

the

pri

mar

yso

lven

t.T

he

inte

rmed

iate

ex-

trac

tp

has

eis

fed

toa

seco

nd

extr

acto

r(c

)an

d

Page 22: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

43

bro

ug

ht

inco

nta

ctw

ith

the

cou

nte

rso

lven

t.T

he

mix

ture

of

cou

nte

rso

lven

tan

din

term

edia

tera

f-fi

nat

eis

fed

toa

colu

mn

(b)

inw

hic

hth

ein

-te

rmed

iate

raffi

nat

ean

dth

eco

un

ters

olv

ent

are

sep

arat

edb

yd

isti

llat

ion

.T

he

pu

rein

term

edia

tera

ffin

ate

isth

enfe

dto

the

firs

tex

trac

tor,

wh

ile

the

cou

nte

rso

lven

tis

char

ged

toth

ese

con

dex

-tr

acto

r.In

this

way

,so

me

of

the

dis

advan

tag

esca

nb

eover

com

e.

Fig

ure

47.

Use

of

counte

rsolv

ent

wit

hin

term

edia

tere

cov-

ery

a)F

irst

extr

acto

r;b)

Dis

till

atio

nco

lum

n;

c)S

econd

extr

ac-

tor

5.2

.C

om

bin

edP

roce

sses

of

Ex

tra

ctio

n

an

dD

isti

lla

tio

n

Aze

otr

op

icD

isti

lla

tio

n.

Usu

ally

itis

nec

es-

sary

toco

mb

ine

extr

acti

on

and

dis

till

atio

np

ro-

cess

esfo

rre

cover

ing

the

solv

ent

fro

mth

eex

-tr

act

ph

ase

and

also

fro

mth

era

ffin

ate

ph

ase,

ifth

eso

lven

tis

solu

ble

inth

era

ffin

ate.

Fig

ure

48

show

sas

anex

amp

leth

ere

cover

yo

fac

etic

acid

fro

man

aqu

eou

sso

luti

on

wit

hm

ethyl

tert

-bu

tyl

eth

er(M

TB

E)

asso

lven

t.T

he

syst

emo

fw

ater

and

acet

icac

idis

ah

igh

lyn

on

-id

ealaz

eotr

op

icm

ixtu

reth

atco

uld

be

sep

arat

edb

ysi

mp

led

isti

llat

ion

.H

ow

ever

,fo

rd

ilu

tefe

edco

mp

osi

tio

ns

solv

ent

extr

acti

on

ism

ore

advan

-ta

geo

us

bec

ause

of

the

ver

yh

igh

ener

gy

dem

and

of

aw

ater

-ric

hfe

edd

isti

llat

ion

.T

he

tria

ng

ula

rd

iag

ram

of

Fig

ure

48

show

sth

atth

eb

inar

ysy

s-

tem

of

solv

entM

TB

Ean

dw

ater

has

ah

eter

og

e-n

eou

saz

eotr

op

e.A

sa

con

seq

uen

ce,

extr

acti

on

has

tob

eco

mb

ined

wit

haz

eotr

op

icd

isti

llat

ion

assh

ow

nin

the

flow

shee

to

fF

igu

re4

8B

.B

yex

trac

tio

nin

the

extr

acto

rE

extr

acti

on

feed

Fis

chan

ged

tora

ffin

ate

Ran

dth

eso

lven

tL

1to

extr

act

ph

ase

F1

,w

hic

ho

nth

eo

ther

han

dis

the

feed

of

dis

till

atio

nco

lum

nC

-1.

InC

-1th

eex

-tr

act

issp

lit

into

the

bo

tto

ms

acet

icac

idB

1an

dan

acet

icac

id-f

ree

dis

till

ate

D1

con

nec

ted

by

the

mai

nb

alan

celi

ne

of

dis

till

atio

nin

the

tria

n-

gle

dia

gra

m.

Th

eac

etic

acid

-fre

era

ffin

ate

Ris

fed

into

colu

mn

C-2

wh

ere

itis

sep

arat

edin

toth

eb

ott

om

s,p

ure

wat

erB

2an

dw

ater

–M

TB

Eaz

eotr

op

eD

2.

Bo

thd

isti

llat

esD

1an

dD

2li

ein

the

imm

isci

ble

reg

ion

bet

wee

nM

TB

Ean

dw

ater

.T

his

mak

essi

mp

led

ecan

tati

on

(S)

of

the

con

den

sed

ph

ases

po

ssib

le.T

he

solv

ent-

rich

frac

tio

nL

1is

no

tfu

rth

erp

uri

fied

sin

ceM

TB

Eas

solv

ent

nee

ds

no

tto

be

pu

re.

So

L1

can

be

recy

cled

dir

ectl

yto

the

extr

acto

rE

,a

par

to

fit

isu

sed

asre

flu

xfo

rC

-1.

Inco

lum

nC

-2a

mix

ture

of

wat

eran

dM

TB

Eh

asb

een

sep

arat

edin

top

ure

wat

eran

dM

TB

E–

wat

eraz

eotr

op

e.T

her

efo

re,

L2

,th

ew

ater

-ric

hp

has

efr

om

the

sett

ler,

can

also

be

fed

into

colu

mn

C-2

.T

he

econom

yof

the

hybri

dpro

cess

dep

ends

on

aca

refu

lo

pti

miz

atio

no

fo

per

atio

nal

and

con

stru

ctio

nal

par

amet

ers,

bes

ides

the

care

ful

sele

ctio

no

fth

eso

lven

t.R

ecen

tly,

mix

edin

te-

ger

no

nli

nea

rp

rog

ram

min

g(M

INL

P)

has

bee

nsu

cces

sfu

lly

intr

od

uce

din

op

tim

izat

ion

of

such

pro

cess

es[9

3],

[94

].M

INL

Pca

nb

eu

sed

asa

pro

cess

syn

thes

isto

ol.

Itis

nec

essa

ryto

gen

-er

ate

aso

-cal

led

super

stru

cture

of

the

hybri

dp

roce

ssw

hic

hco

nta

ins

avar

iety

of

alte

rnat

ive

flow

shee

ts.

Th

enM

INL

Pis

able

toch

oo

seth

eb

estso

luti

on

for

giv

enp

aram

eter

san

dal

sofr

om

com

pet

itiv

eu

nit

op

erat

ion

sli

ke

extr

acti

ve

dis

til-

lati

on

,p

roce

sses

wit

hm

ore

than

on

eso

lven

to

rp

roce

sses

wit

hre

extr

acti

on

for

solv

entre

cover

y.

Ex

tra

ctiv

eD

isti

lla

tio

n.

An

oth

erp

oss

ibil

ity

tose

par

ate

azeo

tro

pic

mix

ture

sis

extr

acti

ve

dis

-ti

llat

ion

.A

solv

ent

wit

ha

mu

chh

igh

erb

oil

-in

gp

oin

tth

anth

efe

edis

fed

atth

eto

po

fa

dis

till

atio

nco

lum

nto

entr

ain

on

eco

mp

on

ent

of

the

dis

till

atio

nfe

edth

aten

ters

the

colu

mn

atth

eb

ott

om

(→D

isti

llat

ion

and

Rec

tifi

cati

on

,C

hap

.6.5

.).T

he

com

bin

edsy

stem

ofli

qu

id–

liq

-u

idex

trac

tio

nan

dex

trac

tive

dis

till

atio

nis

ap-

pli

edin

nea

rly

allp

roce

sses

use

dto

man

ufa

ctu

re

44

Liq

uid

–Liq

uid

Extr

action

ver

yp

ure

lig

htar

om

atic

s.N

-Fo

rmy

lmo

rph

oli

ne

isa

suit

able

solv

ent

tose

par

ate

the

lig

ht

aro

-m

atic

sb

enze

ne

and

tolu

ene

use

das

feed

sto

ckfo

rth

ep

etro

chem

ical

ind

ust

ry[9

5–

10

0].

Du

eto

the

sele

ctiv

ity

of

N-f

orm

ylm

orp

ho

lin

e(N

FM

),ex

trem

ely

hig

hy

ield

so

fver

yp

ure

pro

du

cts

are

ob

tain

ed.

Fig

ure

48.

Tri

angula

rd

iag

ram

(A)

and

flow

shee

t(B

)o

fa

hybri

dex

trac

tion

–d

isti

llat

ion

pro

cess

for

sep

arat

ion

of

wat

eran

dac

etic

acid

wit

hM

TB

Eas

solv

ent

[93

]E

=ex

trac

tion;

C-1

,C

-2=

dis

till

atio

n;

S=

sett

lin

g;

H=

conden

ser

Asi

mp

lifi

edp

roce

ssfl

ow

sch

eme

for

N-

form

ylm

orp

ho

lin

eex

trac

tio

nis

giv

enin

Fig

-u

re4

9.

Fee

den

ters

the

extr

acto

rat

anap

pro

-p

riat

ep

oin

tin

the

bo

tto

mh

alf

of

the

colu

mn

.T

he

exac

tlo

cati

on

dep

end

so

nth

eco

mp

osi

tio

no

fth

efe

edan

dca

nb

eo

pti

miz

edfo

rea

chfe

ed-

sto

ck.

So

lven

ten

ters

atth

eto

po

fth

eex

trac

-to

rat

the

sele

cted

tem

per

atu

re.

Bec

ause

NF

Mh

asa

hig

hso

lven

tp

ow

er,

this

mu

sto

ften

be

re-

du

ced

by

add

itio

no

fw

ater

.In

gen

eral

,4

–1

0%

wat

eris

suffi

cien

tto

ensu

rea

low

solu

bil

ity

of

satu

rate

dhydro

carb

ons

whil

est

illm

ainta

inin

ga

hig

hso

lub

ilit

yo

far

om

atic

s.T

he

raffi

nat

ep

has

ele

avin

gth

eto

po

fth

eex

trac

tor

issa

tura

ted

wit

hso

lven

t.W

ash

ing

wit

hw

ater

has

pro

ved

tob

ea

sim

ple

and

effe

ctiv

em

ean

so

fre

cover

ing

dis

-so

lved

solv

ent.

Th

ew

ater

–so

lven

tmix

ture

fro

mth

isw

ash

ing

op

erat

ion

isch

arg

edto

the

bo

tto

mo

fth

em

ain

extr

acto

rto

incr

ease

the

wat

erco

n-

ten

to

fth

eso

lven

tp

has

eas

dis

cuss

edab

ove.

Th

eso

lven

t–ar

om

atic

sm

ixtu

refr

om

the

bo

t-to

mo

fth

eex

trac

tor

stil

lco

nta

ins

som

eal

kan

es.

Th

isst

ream

isro

ute

dto

anex

trac

tive

dis

till

atio

nco

lum

n.

Inth

elo

wer

par

to

fth

isco

lum

n,

satu

-ra

ted

hydro

carb

ons

are

stri

pped

off

,w

hic

hre

-su

lts

inh

igh

-pu

rity

aro

mat

ics

atth

eb

ott

om

.B

e-ca

use

the

vo

lati

lity

of

alk

anes

inth

ep

rese

nce

of

NF

Mis

mu

chh

igh

erth

anth

ato

far

om

atic

s,th

en

eed

for

shar

pse

par

atio

nis

no

tver

yh

igh

.Atth

eto

po

fth

eex

trac

tive

dis

till

atio

nco

lum

n,

som

eso

lven

tis

add

ed.

Th

isso

lven

tst

ream

serv

esto

was

hb

ack

any

aro

mat

ics

evap

ora

ted

atth

efe

edp

oin

t.T

he

resu

ltin

gto

pp

rod

uct

,th

eref

ore

,has

aver

ylo

war

om

atic

con

ten

tan

dis

ver

yef

fect

ive

asa

refl

ux

inth

eb

ott

om

par

to

fth

eex

trac

tor,

was

hin

go

ut

the

hea

vie

ral

kan

es.

Th

eb

ott

om

pro

du

cto

fth

eex

trac

tive

dis

till

a-ti

on

colu

mn

,co

nsi

stin

go

fso

lven

tan

dver

yp

ure

aro

mat

ics,

isfe

dto

ad

isti

llat

ion

colu

mn

wh

ere

the

aro

mat

ics

are

evap

ora

ted

alo

ng

wit

hw

ater

.T

he

top

pro

du

cto

fth

isco

lum

nis

con

den

sed

and

fed

toa

sett

ler.

Th

eex

trac

ted

aro

mat

ics

are

avai

l-ab

leas

pro

du

cto

rca

nb

ero

ute

dto

ad

isti

lla-

tio

ntr

ain

tose

par

ate

the

ind

ivid

ual

com

po

un

ds.

So

me

of

the

aro

mat

ics

are

retu

rned

toth

eto

po

fth

ed

isti

llat

ion

colu

mn

asre

flu

x.I

nth

isw

ay,a

ny

asce

nd

ing

solv

entv

apo

ris

con

den

sed

and

the

top

pro

du

cts

are

solv

ent-

free

.T

he

wat

erla

yer

fro

mth

ese

ttle

ris

use

dfo

rra

ffin

ate

was

hin

g.

So

me-

tim

es,p

art

of

the

wat

eris

use

das

refl

ux

inst

ead

of

extr

act.

Inth

isco

mb

inat

ion

,u

ltim

ate

use

ism

ade

of

the

solv

ent

char

acte

rist

ics

inb

oth

the

extr

acti

on

and

the

extr

acti

ve

dis

till

atio

nst

eps.

5.3

.R

eact

ive

Ex

tra

ctio

n

5.3

.1.

Intr

od

uct

ion

Ifth

eso

lven

tre

acts

wit

hth

eex

trac

ted

sub

stan

ced

uri

ng

the

extr

acti

on

,th

ew

ho

lep

roce

ssis

call

edre

acti

ve

extr

acti

on

.T

his

reac

tio

nis

no

rmal

ly

Page 23: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

45

Fig

ure

49.

Morp

holi

ne

solv

ent

pro

cess

a)E

xtr

acto

r;b)

Was

hin

g;

c)E

xtr

acti

ve

dis

till

atio

nco

lum

n;

d)

Dis

till

atio

nco

lum

n;

e)S

ettl

er

use

dto

alte

rth

epro

per

ties

of

inorg

anic

cati

ons

that

are

tob

eex

trac

ted

fro

man

aqu

eou

sso

lu-

tio

nto

mak

eth

emso

lub

lein

the

no

np

ola

ro

r-gan

icso

lven

t.T

he

reac

tion

mec

han

ism

can

bes

tb

eco

mp

ared

wit

ha

cati

on

exch

an

ge

pro

cess

.T

he

solv

entac

tsli

ke

ali

qu

idio

nex

chan

gin

gth

eio

nto

be

extr

acte

dfo

rp

roto

ns.

Ta

ble

1.

Co

mm

erci

alch

elat

ing

extr

acti

on

reag

ents

Nam

eP

rod

uce

rC

hem

ical

com

po

siti

on

LIX

63

Hen

kel

5,8

-die

thyl-

7-h

ydro

xy-6

-dodec

anone

ox

ime

LIX

64

Hen

kel

2-h

ydro

xy-5

-dodec

ylb

enzo

phen

one

oxim

e

LIX

64

NH

enkel

LIX

65

Nw

ith

add

edL

IX6

3(p

rom

ote

r)

LIX

65N

Hen

kel

2-h

ydro

xy-5

-nonylb

enzo

phen

one

oxim

e

LIX

70

Hen

kel

chlo

rin

ated

LIX

65

Nw

ith

add

edL

IX6

3

(pro

mo

ter)

LIX

71

Hen

kel

mix

ture

of

LIX

64

Nan

dL

IX7

0

LIX

73

Hen

kel

mix

ture

of

LIX

64

Nan

dL

IX7

0

LIX

34

Hen

kel

8-(

p-d

od

ecy

lph

eny

lsu

lfo

nam

ido

)qu

ino

lin

e

LIX

54

Hen

kel

acet

yl-

p-d

od

ecy

lac

eto

ph

eno

ne

LIX

62

2H

enkel

LIX

60

22

Hen

kel

SM

E529

Shel

l2-h

ydro

xy-5

-nonyla

ceto

phen

one

oxim

e

SM

E5

30

Sh

ell

SM

E5

29

wit

hk

inet

icm

od

ifier

P1

7A

corg

aphen

yl

ben

zyl

ket

one

oxim

e

P50

Aco

rga

subst

itute

dsa

licy

lal

doxim

e

P5100

Aco

rga

one

par

tP

50

wit

heq

ual

par

tnonylp

hen

ol

P5200

Aco

rga

one

par

tP

50

wit

htw

opar

tsnonylp

hen

ol

P5300

Aco

rga

one

par

tP

50

wit

hth

ree

par

tsnonylp

hen

ol

P5050

Aco

rga

two

par

tsP

50

wit

hone

par

ttr

idec

anol

Kel

ex100

Sher

exsu

bst

itute

d8-h

ydro

xyquin

oli

ne

wit

h10

%

iso

dec

ano

l

Kel

ex1

20

Sh

erex

sim

ilar

toK

elex

10

0bu

tw

ith

20

%

iso

dec

ano

l

Th

eu

seo

fth

isp

roce

ssfo

rex

trac

tio

no

fan

-io

ns

isfa

rle

ssk

now

nbu

tis

of

the

sam

eim

po

r-

tan

ce.

Th

em

ech

anis

mo

fth

isty

pe

of

reac

tio

np

roce

eds

mo

sto

fth

eti

me

thro

ug

hio

np

air

for-

mat

ion

and

can

bes

tb

eco

mp

ared

wit

han

an

ion

exch

an

ge

pro

cess

.A

thir

dp

oss

ible

mec

han

ism

isth

eso

lva

tin

g

an

d/o

rch

ela

tin

gre

act

ion

.In

are

acti

on

of

this

type,

one

or

more

mole

cule

sof

wat

erin

the

hy-

dra

tela

yer

of

the

ion

sar

ere

pla

ced

by

the

acti

ve

solv

ent.

Th

en

ewco

mp

lex

wil

lb

ein

solu

ble

inw

ater

bu

tso

lub

lein

the

solv

ent.

Gen

eral

ly,

the

form

atio

no

fa

com

ple

xis

asl

ow

reac

tio

n.

Th

eref

ore

,in

man

yca

ses,

itis

no

tp

oss

ible

tou

seco

lum

ns

for

this

typ

eo

fex

-tr

acti

on

.In

man

yap

pli

cati

on

sm

ixer

–se

ttle

rar

eu

sed

tom

ake

the

extr

acti

on

po

ssib

le.

Are

acti

ve

extr

acti

on

wil

lnee

da

re-e

xtr

acti

on

tois

ola

teth

eex

trac

ted

sub

stan

cefr

om

the

sol-

ven

t.T

he

acti

ve

solv

ents

use

din

reac

tive

extr

ac-

tio

ns

are

wat

erin

solu

ble

com

po

un

ds.

Th

eyar

eu

sed

un

dil

ute

do

rin

solu

tio

nin

anin

ert

solv

ent.

5.3

.2.

Ex

tra

ctio

nM

ech

an

ism

of

Dif

fere

nt

Ty

pes

of

So

lven

t

Cla

ssic

al

Co

mp

lex

ing

an

d/o

rC

hel

ati

ng

Ag

ents

.T

he

acti

ve

solv

ents

are

usu

ally

larg

e,p

oly

fun

ctio

nal

mo

lecu

les.

Mo

sto

fth

emar

ed

e-si

gned

toex

trac

tsp

ecifi

cca

tions.

Dio

xim

es,hy-

dro

xy

ox

imes

,q

uin

oli

nes

-dik

eto

nes

,et

c.,

are

rath

erex

pen

sive

bu

tw

idel

yu

sed

solv

ents

toex

-tr

act

met

alio

ns

such

asco

pp

eran

dn

ickel

fro

mth

eaq

ueo

us

ph

ase.

46

Liq

uid

–Liq

uid

Extr

action

Met

alco

mp

lexes

are

form

edin

the

wat

erp

has

ein

asu

bst

ance

-sp

ecifi

cp

Hra

ng

ean

dex

-tr

acte

din

toan

iner

tso

lven

t.A

fter

extr

acti

on

the

met

alio

nis

lib

erat

edfr

om

the

com

ple

xb

ych

ang

ing

the

pH

,an

dre

-ex

trac

ted

into

the

wat

erp

has

e.T

he

com

ple

xin

g/c

hel

atin

gag

ents

are

de-

sig

ned

such

that

they

are

chem

ical

lyst

able

,no

n-

tox

ic,a

nd

inso

lub

lein

wat

erto

min

imiz

elo

sses

.T

he

liq

uid

ion

exch

ang

e(L

IX)

[5]

agen

tsu

sed

inth

ep

rod

uct

ion

of

cop

per

are

typ

ical

for

this

cate

go

ry.

Hen

kel

,H

oec

hst

,S

hel

l,S

her

ex,

and

Aco

rga

are

the

larg

est

pro

duce

rsof

com

ple

x-

ing

/ch

elat

ing

extr

acta

nts

(see

Tab

le1

).

Ph

osp

ho

ric,

Su

lfo

nic

,a

nd

Ca

rbo

xy

lic

Aci

ds.

Th

iscl

ass

of

pro

du

cts

acts

typ

ical

lyas

cati

on

exch

ang

ers

inso

luti

on

.Th

ep

rod

uct

sh

ave

on

eo

rm

ore

pro

ton

sth

atca

nb

eex

chan

ged

for

met

alio

ns.

Nap

hth

enic

acid

sV

ersa

tic

acid

s

Su

lfo

nic

acid

sP

ho

sph

ori

cac

ids

Th

iop

ho

sph

ori

cac

ids

Ph

osp

ho

nic

acid

s

Th

em

etal

salt

so

fth

ese

acid

sar

eso

lub

lein

mo

stn

on

po

lar

solv

ents

and

,d

epen

din

go

nth

ep

Ho

fth

eex

trac

tio

nan

dth

ep

Ka

of

the

acid

,th

eca

tion

wil

lm

igra

teto

the

org

anic

phas

eor

stay

inth

ew

ater

ph

ase.

Th

ed

epen

den

ceo

fth

ed

istr

ibu

tio

ns

coef

fici

ents

on

pH

issh

ow

nin

Fig

-u

re5

0.

Th

ed

iffe

ren

tcu

rves

giv

eth

evar

iati

on

of

the

dis

trib

uti

on

coef

fici

ent

Din

dep

end

ence

of

pH

for

dif

fere

ntca

tio

ns.

Th

ese

solv

ents

are

no

tsp

e-ci

fic

for

cert

ain

cati

on

s,bu

tar

ever

ysu

itab

leto

con

cen

trat

ean

dre

cup

erat

etr

ace

elem

ents

fro

mef

flu

ent

stre

ams

[10

9],

[11

0].

Th

em

ajo

rp

rod

uce

rso

fth

isty

pe

of

com

-p

ou

nd

sar

eB

ayer

,Ho

ech

st,D

aih

ach

i,S

hel

l,an

dA

lbri

gh

t&W

ilso

n.

Eth

ers

an

dT

hio

eth

ers.

R2

O+

HX

⇋R

2O

H+

+X−

R2

S+

HX

⇋R

2S

H+

+X−

wh

ere

HX

stan

ds

for

ast

ron

gac

id,e.

g.,

H2S

O4

or

HC

l,an

dX

isth

ean

ion

icre

sto

fth

eac

id.

Mo

stm

etal

ion

sth

atar

eca

pab

leo

ffo

rmin

gan

-io

nic

com

ple

xes

are

extr

acta

ble

wit

het

her

san

dth

ioet

her

s.F

e,A

u,

In,

Ga,

etc.

can

be

extr

acte

dw

ith

thes

eso

lven

tsfr

om

anaq

ueo

us

HC

lso

lu-

tio

n(H

Clco

nce

ntr

atio

n>

6M

)an

dre

-ex

trac

ted

from

the

org

anic

phas

ew

ith

wat

er.M

ost

of

thes

ean

ion

icco

mp

lexes

form

stro

ng

acid

sw

hic

hp

ro-

ton

ate

wit

hth

eet

her

gro

up

tofo

rmo

xo

niu

m(t

hio

niu

m)

salt

s.T

hes

esa

lts,

how

ever

,ar

eso

l-u

ble

inet

her

or

thio

eth

er.

Itis

also

po

ssib

leto

extr

act

Cl−

fro

mw

ater

wit

h(R

2O

) 2·

H2S

O4,

the

sulf

ate

ion

bei

ng

rep

lace

db

yth

ech

lori

de.

Th

isty

pe

of

solv

ent

isn

orm

ally

use

din

un

di-

lute

dfo

rm[1

06

].

Ket

on

esex

trac

tth

esa

me

anio

nic

com

ple

xes

aset

her

s,bu

tin

mo

stca

ses

atlo

wer

acid

con

cen

trat

ion

.C

om

ple

xes

wit

hw

eaker

acid

sca

nal

sobe

extr

acte

d.

Met

hyl

isobuty

lke-

ton

ean

dcy

clo

hex

ano

ne

are

ind

ust

rial

lyu

sed

inth

ese

par

atio

no

fN

b–

Ta

asF−

com

ple

xes

[11

2]

(→N

iob

ium

and

Nio

biu

mC

om

po

un

ds,

Ch

ap.4

.3.1

.)an

din

the

sep

arat

ion

of

Zr–

Hf

asC

NS−

com

ple

xes

(→Z

irco

niu

man

dZ

irco

niu

mC

om

po

un

ds,

Ch

ap.

1.4

.2.)

[11

6].

Th

eso

lven

tsar

eu

sed

inu

nd

ilu

ted

form

.A

gre

atd

isad

van

-ta

ge

of

this

and

of

the

form

erty

pe

of

solv

ents

isth

atth

eyar

en

ot

com

ple

tely

inso

lub

lein

wat

er.

Ad

isti

llat

ion

isn

eed

edto

rem

ove

the

dis

solv

edso

lven

tfr

om

the

wat

erp

has

e.

Tri

alk

ylp

ho

sph

ine

ox

ides

,T

ria

lky

lph

os-

ph

ina

tes,

-ph

osp

ho

na

tes,

an

d-p

ho

sph

ate

s.

R3

PO

+H

X⇋

R3

PO

H+

+X−

RO

R2

PO

+H

X⇋

RO

R2

PO

H+

+X−

(RO

) 2R

PO

+H

X⇋

(RO

) 2R

PO

H+

+X−

(RO

) 3P

O+

HX

⇋(R

O) 3

PO

H+

+X−

Page 24: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

47

Fig

ure

50.

Plo

tsof

log

Dvs.

pH

for

extr

acti

on

of

met

als

Wit

hth

isty

pe

of

extr

acta

nts

mo

stm

etal

sfr

om

gro

up

3to

gro

up

8ca

nb

eex

trac

ted

,ev

enif

on

lyw

eak

com

ple

xes

are

form

edw

ith

the

solv

ent.

Itis

for

exam

ple

po

ssib

leto

extr

act

TiO

SO

4

[11

4]

fro

ma

sulf

uri

cac

idso

luti

on

wit

hd

ibu

tyl

bu

tylp

ho

sph

on

ate

(DB

BP

)as

the

solv

ated

com

-p

lex

2D

BB

P·T

iOS

O4·

H2S

O4·

5H

2O

.T

hes

eorg

anophosp

horu

sso

lven

tsar

e,due

toth

eir

out-

stan

din

gch

emic

alst

abil

ity

and

good

physi

cal

pro

per

ties

,m

ost

wid

ely

use

din

reac

tive

extr

ac-

tio

n[1

07

],[1

08

].F

ree

acid

sca

nal

sob

eex

trac

ted

,th

eb

asic

-it

yo

fth

eso

lven

tsd

ecre

ases

fro

mp

ho

sph

ine

ox

ide

totr

ialk

ylp

ho

sph

ate.

Th

ed

istr

ibu

tio

nco

-ef

fici

ents

are

rath

ersm

all

soth

atla

rge

vo

lum

eso

fso

lven

tar

en

eed

edin

anex

trac

tio

np

roce

ss[1

04

],[1

05

],[1

11

].T

hes

eex

trac

tan

tsar

eu

sed

assu

cho

rd

ilu

ted

inan

iner

tso

lven

t(p

etro

leu

mfr

acti

on

)w

ith

or

wit

ho

ut

mo

difi

er.T

he

dis

trib

u-

tio

nco

effi

cien

tsin

met

alex

trac

tio

nar

eu

sual

lyver

yh

igh

and

dep

end

on

the

acid

con

cen

trat

ion

.T

he

pro

du

cts

are

rath

erex

pen

sive.

Bay

er,

Ho

ech

st,

Dai

hac

hi,

Sh

ell,

and

Al-

bri

gh

t&W

ilso

nar

eth

em

ajo

rp

rod

uce

rs.

Tri

alk

yls

ulf

on

ium

(Sel

eniu

m,

Tel

luri

um

),T

etra

alk

yla

mm

on

ium

,a

nd

Tet

raa

lky

lph

os-

ph

on

ium

(Ars

on

ium

,S

tib

on

ium

)S

alt

s.

[R4

N+

A−

] Solv

ent

+[B−

] Raffi

nate

[R4

N+

B−

] Solv

ent

+[A−

] Raffi

nate

Th

ese

on

ium

com

po

un

ds

form

ion

sb

oth

inac

idic

and

bas

icm

ediu

m.

Th

em

ech

anis

mo

fex

trac

tio

nis

pra

ctic

ally

alw

ays

anio

nex

chan

ge

[10

6].

Th

eo

niu

mco

mp

ou

nd

sar

ere

gen

erat

edin

the

sam

ew

ayas

anio

nex

chan

ger

resi

ns

by

re-

extr

acti

on

wit

ha

bas

e.T

hes

eso

lven

tsar

eu

sed

inth

ep

rod

uct

ion

of

Cr,

V,

Re,

Tc,

Mo

,an

dW

asa

solu

tio

nin

ap

etro

leu

mfr

acti

on

.

Pro

du

cers

are

Hen

kel

,S

her

ex,

Ho

ech

st,

and

BA

SF.

Am

ine

an

dP

ho

sph

ine

Sa

lts.

R3

N+

HX−→

R3

NH

++

X−

R3

P+

HX−→

R3

PH

++

X−

Pri

mar

y,se

con

dar

y,an

dte

rtia

ryam

ines

mu

stb

ep

roto

nat

ed,

thu

sco

nver

ted

toth

eio

nic

form

bef

ore

they

can

be

use

das

anio

nex

chan

ger

.T

hu

sac

ids

can

be

extr

acte

dw

ith

free

amin

es,

met

als

hav

eto

be

tran

sfo

rmed

toth

eco

rre-

spo

nd

ing

acid

s:van

adiu

mca

nb

eex

trac

ted

asH

VO

3,

chro

miu

mas

H2C

r 2O

7,

and

man

gan

ese

asH

Mn

O4.M

ost

use

dar

eth

ete

rtia

ryam

ines

be-

cau

seth

eyar

ech

emic

ally

iner

tto

mo

stre

agen

ts.

Inth

esy

stem

tril

aury

lam

ine

–ci

tric

acid

are

ver

sib

leex

trac

tio

nca

nb

ese

tu

p,

du

eto

the

dif

fere

nce

ind

istr

ibu

tio

nco

effi

cien

tat

dif

fer-

ent

tem

per

atu

res.

At

low

tem

per

atu

re(2

0◦C

),th

ed

istr

ibu

tio

nco

effi

cien

tso

lven

t/ra

ffin

ate

is>

10

.A

th

igh

tem

per

atu

re(1

30◦C

),th

eco

effi

-ci

ent

for

the

sam

esy

stem

is<

1.

Th

us,

the

acid

can

be

extr

acte

dfr

om

wat

erat

low

tem

per

atu

rean

dre

-ex

trac

ted

wit

hw

ater

ath

igh

tem

per

atu

re.

Mu

chle

ssac

cou

nte

dfo

ris

the

fact

that

thes

eam

ines

hav

ever

yd

iffe

ren

td

istr

ibu

tio

nco

effi

-ci

ents

for

dif

fere

nt

anio

ns.

[R3

NH

+A−

] Solv

ent

+[B−

] Raffi

nate

[R3

NH

+B−

] Solv

ent

+[A−

] Raffi

nate

Fo

rtr

ioct

yla

min

ein

anar

om

atic

solv

ent

the

or-

der

of

extr

acta

bil

ity

is

I−≫

Br−

>N

O− 3

>C

l−

≫F−

>S2

O2−

3>

PO

3−

4>

SO

2−

4

48

Liq

uid

–Liq

uid

Extr

action

Th

isse

ries

isd

epen

den

to

nth

ety

pe

of

amin

e,th

ed

ilu

ent,

and

the

tem

per

atu

rean

dm

ust

be

de-

term

ined

for

any

giv

ensy

stem

[5].

Th

isse

ries

can

be

enla

rged

for

org

anic

com

pounds,

capa-

ble

of

form

ing

ion

pai

rsw

ith

the

amin

e.P

hen

ols

and

sub

stit

ute

dp

hen

ols

can

be

extr

acte

dw

ith

bet

ter

dis

trib

uti

on

coef

fici

ents

than

chlo

rid

es.In

this

seri

esth

iop

hen

ols

and

som

em

erca

pta

ns

are

situ

ated

bet

wee

nb

rom

ide

and

nit

rate

and

allsu

l-fo

nic

acid

sar

eb

ette

rex

trac

ted

than

ph

osp

hat

e.T

his

mak

esth

esu

lfat

esa

lts

of

amin

esa

ver

yg

oo

dch

oic

efo

rn

ewex

trac

tio

nsy

stem

s.(R

3N

) 2·

H2S

O4

(R=

oct

yl)

isca

pab

leo

fex

-tr

acti

ng

Cl−

and

/or

NO− 3

[11

3]

fro

ma

mix

ture

of

bo

than

ion

sw

ith

SO

2−

4.T

he

val

ue

of

the

dis

-tr

ibu

tio

nco

effi

cien

to

fth

ean

ion

sis

surp

risi

ng

lyh

igh

.

DC

l/D

SO

4≈

100

DN

O3/D

SO

4≈

400

Ad

isad

van

tag

eo

fth

ese

solv

ents

isth

efa

ctth

atp

erm

ole

amin

eo

ne

mo

leo

fsa

ltis

form

edaf

-te

rre

gen

erat

ion

.H

ow

ever

,m

ost

of

the

tim

e,th

ean

ion

sto

be

rem

oved

are

pre

sen

tin

the

solu

-ti

on

on

lyas

trac

eim

pu

riti

es,

soth

atth

isd

raw

-b

ack

isn

ot

sig

nifi

can

t.A

no

ther

dis

advan

tag

eo

fam

ines

isth

ep

oo

rso

lub

ilit

yo

fam

mo

niu

msa

lts

inal

iphat

ichydro

carb

ons.

To

avoid

thir

dp

has

efo

rmat

ion

,th

eu

seo

far

om

atic

solv

ents

(sm

ell)

or

alip

hat

ics

wit

hm

od

ifier

sis

nec

essa

ry.

Am

ines

can

also

act

asso

lvat

ing

agen

tsin

anac

idm

ediu

m.

Iro

n,

zin

c,an

du

ran

ium

salt

sca

nb

eex

trac

ted

inth

isw

ay[1

06

].

5.3

.3.

Use

s

1)

Ab

leed

fro

ma

(NH

4) 2

SO

4cr

yst

alli

zati

on

un

itin

aca

pro

lact

amp

lan

tco

nta

ins

40

%(N

H4) 2

SO

4,

10

%N

O− 3

,5

0p

pm

Cl−

and

3–

4%

org

anic

sulf

on

icac

ids.

Th

eso

lu-

tio

nis

extr

acte

db

ytr

ioct

yla

mm

on

ium

sul-

fate

,th

ead

ded

amo

un

tis

sto

ich

iom

etri

cto

[NO− 3

]+

[Cl−

]+

[su

lfo

nic

acid

].In

thre

est

ages

>9

9%

of

the

nit

rate

,9

0%

of

the

chlo

rid

e,an

d8

5%

of

the

sulf

on

icac

ids

are

extr

acte

db

yth

etr

ioct

yla

min

ein

solu

tio

n(4

0%

)in

Shel

lsol

AB

(aro

mat

ichydro

car-

bo

n).

Th

era

ffin

ate

isre

turn

edto

the

cry

stal

-li

zati

on

pla

nt

for

(NH

4) 2

SO

4re

cover

y.T

he

re-e

xtr

act

con

tain

s3

5%

of

nit

rate

,0

.01

6%

of

chlo

rid

e,th

esu

lfo

nic

acid

s,an

do

nly

0.1

%o

fsu

lfat

ean

dis

trea

ted

sep

arat

ely.

Co

mp

ared

wit

ha

conven

tio

nal

stri

pp

ing

,th

eu

seo

fch

emic

als

inth

issy

stem

isst

ron

gly

red

uce

d.

80

%le

ssN

aOH

isco

nsu

med

be-

cau

seth

eb

ase

iso

nly

use

dto

lib

erat

eth

eam

ine

and

no

tto

neu

tral

ize

the

NH

3fr

om

(NH

4) 2

SO

4[1

13

].2

)T

race

so

fp

hen

ol(2

0–

20

0p

pm

)an

db

isp

he-

no

l(2

0–

10

0p

pm

)ca

nb

eex

trac

ted

fro

mth

ew

aste

wat

ero

fa

po

lyca

rbo

nat

ep

lan

tto

val

ues

<1

pp

m,

thu

sav

oid

ing

bio

log

ical

trea

tmen

to

fth

ew

ater

.T

he

re-e

xtr

act

con

-ta

inin

gso

diu

mp

hen

ola

tean

db

isp

hen

ola

te(3

00

–5

00

tim

esm

ore

con

cen

trat

ed)

can

be

retu

rned

toth

ep

oly

carb

on

ate

pla

nt.

Th

eso

l-ven

tuse

dis

5%

trio

cty

lam

ine

inS

hel

lso

lAB

[11

7].

3)

Fro

ma

pla

nt

for

the

pro

du

ctio

no

fv

ulc

an-

izat

ion

acce

lera

tors

2-m

erca

pto

ben

zoth

iazo

l(1

00

–3

00

pp

m)

and

its

ox

idat

ion

pro

du

cts

are

com

ple

tely

extr

acte

din

two

stag

esan

dre

-ex

trac

ted

asa

20

–3

0%

solu

tio

n.

Th

isco

nce

ntr

ated

was

teca

nb

eea

sily

rem

oved

.T

he

solv

ent

is2

0%

trio

cty

lam

ine

inS

hel

l-so

lA

B[1

13

].4

)B

rom

ide

ion

sca

nb

eex

trac

ted

sele

ctiv

ely

fro

mse

aw

ater

(co

nce

ntr

atio

nin

the

Dea

dS

ea≈

4%

)w

ith

amin

ehydro

chlo

rides

and

con

cen

trat

edin

are

-ex

trac

tio

nst

ep,

thu

sav

oid

ing

the

ener

get

ical

lyu

nfa

vo

rab

lest

rip

-p

ing

of

sea

wat

er.T

he

extr

acti

on

can

be

car-

ried

ou

tw

ith

var

iou

sty

pes

of

amin

esas

HC

lo

rH

2S

O4

salt

[10

6].

5)

Mg2+

can

be

rem

oved

fro

ma

satu

rate

dso

-lu

tio

no

f(N

H4) 2

SO

4b

yex

trac

tio

nw

ith

the

amm

oniu

msa

ltof

die

thylh

exyl

phosp

honic

acid

(DE

HPA

)at

pH

>5

.It

can

be

reco

ver

edb

ylo

wer

ing

the

pH

to<

3[1

15

].6

)T

race

so

fu

ran

ium

are

extr

acte

dfr

om

ph

os-

ph

ate

ore

s.T

he

ura

niu

mco

nte

nti

nth

ese

ore

sis

on

ly3

0–

30

0p

pm

.T

he

rese

rves

of

tho

seo

res

are

soh

ug

eth

atth

eq

uan

tity

of

ura

niu

mfr

om

ph

osp

hat

esm

any

tim

esex

ceed

sth

ato

fu

ran

ium

fou

nd

ino

ther

ura

niu

mo

res.

7)

Lan

than

ides

and

acti

nid

esh

ave

on

lyre

cen

tly

bec

om

eav

aila

ble

inh

igh

erq

uan

tity

and

hig

hp

uri

ty.T

his

was

enab

led

by

the

dev

elo

pm

ent

of

the

extr

acti

on

tech

no

log

y(→

Rar

eE

arth

Ele

men

ts).

Page 25: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

49

8)

Wo

rld

wid

eab

ou

t4

0%

of

the

cop

per

isp

ro-

du

ced

by

reac

tive

extr

acti

on

.T

he

pla

nts

are

ano

rder

of

mag

nit

ud

ela

rger

then

any

oth

erty

pe

of

solv

ent

extr

acti

on

pre

sen

tly

ino

per

-at

ion

(→C

op

per

,C

hap

.5

.8.)

.W

ith

anaq

ue-

ou

sfe

edo

f2

00

–3

00

0m

3/h

aw

ho

len

ewte

chn

olo

gy

had

tob

ed

evel

op

ed.C

op

per

can

be

extr

acte

daf

ter

acid

or

amm

on

iaca

lle

ach

-in

g.T

he

aqu

eou

sst

rip

pin

gp

has

eis

use

dd

i-re

ctly

inth

eel

ectr

ow

inn

ing

of

cop

per

.T

oav

oid

the

bu

ild

-up

of

imp

uri

ties

inth

eel

ec-

tro

lysi

so

fco

pp

er,

Fe,

Zn

,an

do

ther

met

als

are

rem

oved

fro

mth

isp

has

eb

yex

trac

tio

nw

ith

oth

erso

lven

ts[5

],[1

02

],[1

11

].9

)M

ore

than

90

%o

fth

ew

orl

dp

rod

uct

ion

of

cob

alt

isp

erfo

rmed

by

reac

tive

extr

acti

on

.S

epar

atio

no

fC

oan

dN

ica

nb

eac

hie

ved

fro

mal

kal

ine,

neu

tral

,o

rfr

om

acid

icm

edia

.M

ost

of

the

imp

uri

ties

(Sn

,B

i,F

e,P

b,

Cu

,C

d,a

nd

Zn

)h

ave

tob

ere

moved

fro

mth

eso

-lu

tio

nb

yp

reci

pit

atio

no

rex

trac

tio

n.F

rom

am

ediu

mco

nce

ntr

ated

aqu

eou

sch

lori

de

solu

-ti

on

(10

0–

20

0g

/L),

Co

can

be

extr

acte

db

yam

ines

tog

eth

erw

ith

on

lytr

aces

of

Ni.

Aft

ersc

rub

bin

gw

ith

4–

5M

HC

l,m

ost

of

the

Ni

isre

moved

fro

mth

eso

lven

t.T

he

cob

alt

isst

rip

ped

by

wat

er.

Fro

mn

eutr

alo

rw

eak

lyac

idic

med

ia(p

H4

.8–

5.5

)C

oca

nb

eex

trac

ted

by

the

Na+

or

NH

+ 4sa

ltof

di-

2-e

thylh

exylp

hosp

hori

cac

id(D

2E

HPA

)(t

oav

oid

acid

ifica

tio

no

fth

eaq

ueo

us

solu

tio

n).

So

me

Ni

isco

-ex

trac

ted

and

isre

moved

by

scru

bb

ing

wit

ha

Co

solu

-ti

on

thu

sre

pla

cin

gan

yex

trac

ted

Ni

by

Co

.C

ois

fin

ally

stri

pp

edb

yH

Cl,

H2S

O4,

or

HN

O3

dep

end

ing

on

the

use

.T

he

use

of

mo

no

oct

yl

oct

ylp

ho

sph

on

icac

id(M

OO

P)

tore

pla

ceD

2E

HPA

[10

1]

per

mit

sth

esa

me

sep

arat

ion

,bu

tatl

ow

erp

Han

dw

ith

enh

ance

dd

istr

ibu

tio

nco

nst

ants

for

Co

.In

alk

alin

eso

luti

on

Co

and

Ni

can

be

ex-

trac

ted

by

LIX

agen

tsfr

om

amm

on

iaca

lso

-lu

tio

n.

Pri

or

toth

eex

trac

tio

n,

cob

alt

iso

x-

idiz

edto

the

Co3+

stat

e.N

ickel

isst

rip

ped

firs

tw

ith

dil

ute

acid

,C

ore

mai

nin

gin

the

solv

ent.

Co

bal

tis

then

red

uce

dto

the

Co2+

stat

ean

dst

rip

ped

wit

hd

ilu

ted

acid

[5],

[10

2],

[10

4],

[10

5].

All

thes

eex

amp

les

are

use

din

ind

ust

ryo

rin

pil

ot

pla

nts

.E

lab

ora

tep

roce

ssan

dfl

ow

con

tro

l

are

esse

nti

alto

use

this

tech

no

log

yin

aec

on

om

-ic

alan

dm

ean

ing

ful

way

.

5.3

.4.

Set

tin

gu

pa

nE

xtr

act

ion

Sy

stem

Aso

luti

on

Rco

nta

ins

thre

eco

mp

on

ents

:ac

id,

met

alA

and

met

alB

.B

oth

met

als

and

the

acid

are

extr

acta

ble

wit

ha

solv

ent

San

dm

etal

Ais

the

des

ired

com

po

nen

tth

atis

tob

eo

bta

ined

inac

idso

luti

on

.T

he

pro

ced

ure

tose

tu

pa

new

ex-

trac

tio

nsy

stem

wit

hth

ese

dat

ais

typ

ical

for

any

reac

tive

extr

acti

on

syst

em[1

14

],[1

18

].T

he

dis

trib

uti

on

coef

fici

ents

are

tob

em

ea-

sure

dat

dif

fere

nt

acid

con

cen

trat

ion

sat

ate

m-

per

atu

resu

itab

lefo

rth

eex

trac

tio

n.

Aty

pic

alm

easu

rem

ent

curv

eis

show

nin

Fig

ure

51

.

Fig

ure

51.

Dis

trib

uti

on

coef

fici

ent

indep

enden

ceon

acid

conce

ntr

atio

n

Th

ed

iag

ram

show

sa

po

or,

pra

ctic

ally

con

-st

ant

dis

trib

uti

on

coef

fici

ent

Dfo

rth

eac

idan

dan

incr

easi

ng

on

efo

rb

oth

met

als

Aan

dB

atin

crea

sin

gac

idco

nce

ntr

atio

n.

Th

ism

ean

sth

atth

eac

idex

trac

tio

nis

infa

cta

norm

alphysi

cal

extr

acti

on

and

that

both

met

als

form

solv

atio

nco

mp

lexes

.A

tan

yac

idco

nce

n-

trat

ion

,al

lth

ree

com

po

nen

tsar

eex

trac

ted

to-

get

her

.T

he

extr

acti

on

coef

fici

ents

Ear

ere

late

din

the

sam

ew

ayas

are

the

dis

trib

uti

on

coef

fi-

cien

ts,

E=

D·S

/R

.

To

extr

act

met

alA

com

ple

tely

and

ina

reas

on

-ab

len

um

ber

of

step

sex

trac

tio

nh

asto

be

carr

ied

ou

tin

zon

e4

of

Fig

ure

51

,th

eex

tra

ctio

nzo

ne.

At

the

sam

eti

me,

met

alB

and

the

acid

are

on

lyp

arti

ally

extr

acte

din

toth

eso

lven

t.T

he

nu

m-

ber

of

step

sca

nb

eca

lcu

late

dw

ith

the

Kre

mse

rfo

rmu

la.T

he

Kre

mse

rfo

rmu

laca

lcu

late

sth

eef

-fi

cien

cyZ

inth

eex

trac

tio

n

Z=

(

En

+1−

E)

/(

En

+1−

1)

50

Liq

uid

–Liq

uid

Extr

action

over

nst

ages

.F

or

this

equ

atio

nth

en

um

ber

of

stag

esca

nea

sily

be

calc

ula

ted

n=

log{[

1/

(1−

Z)·(

1−

1/E

)]+

1/E}

/lo

gE

To

rem

ove

met

alB

fro

mth

eso

lven

tth

eso

lven

th

asto

be

was

hed

wit

hw

ater

orac

idin

such

aw

ayth

atm

ost

of

met

alA

stay

sin

the

solv

ent,

wh

ile

met

alB

isw

ash

edo

utas

com

ple

tely

asp

oss

ible

.T

his

isd

on

ein

zon

e3

ofF

igu

re5

1,t

he

scru

bb

ing

zon

e.T

he

amo

un

to

fw

ater

tob

eu

sed

isg

iven

agai

nby

the

dis

trib

uti

on

coef

fici

ents

ofboth

acid

and

met

alB

.If

too

mu

chac

idis

rem

oved

,m

etal

Aw

ill

also

be

was

hed

ou

t.T

her

efo

reit

ism

ore

adeq

uat

eto

use

anac

idso

luti

on

.T

he

con

cen

-tr

atio

no

fth

ed

ilu

teac

idsh

ou

ldb

esu

chth

atth

eac

idso

luti

on

can

on

lyta

ke

up

the

amo

un

to

fac

idto

be

rem

oved

fro

mth

eso

lven

t.B

ysc

rub

-b

ing

wit

hp

ure

wat

ero

nly

ali

mit

edam

ou

nt

of

scru

bb

ing

flu

idca

nb

eu

sed

bec

ause

of

the

low

dis

trib

uti

on

coef

fici

ent

of

the

acid

.B

yad

din

ga

calc

ula

ted

amo

un

to

fac

idth

eam

ou

nt

of

scru

b-

bin

gfl

uid

can

be

incr

ease

dan

dm

ore

com

po

nen

tB

can

be

rem

oved

wit

ho

utre

mov

ing

com

po

nen

tA

.Th

era

ffin

ate,

leav

ing

the

scru

bb

ing

zon

eco

n-

tain

sto

om

uch

of

met

alA

tob

ed

isca

rded

and

isse

nt

bac

kto

on

eo

fth

est

eps

inth

eex

trac

tio

n.

The

num

ber

ofst

eps

can

agai

nbe

calc

ula

ted

wit

hth

eK

rem

ser

form

ula

.In

zon

e2

of

Fig

ure

51

,th

est

rip

pin

gzo

ne,

met

alA

isw

ash

edo

ut

of

the

solv

ent

wit

hw

ater

or

ad

ilu

teac

idso

luti

on

.T

he

amo

un

to

fw

ater

isch

ose

nsu

chas

too

bta

inth

ed

esir

edco

nce

ntr

a-ti

on

of

met

alA

inth

ere

-ex

trac

t.W

ith

the

giv

end

istr

ibu

tio

nco

effi

cien

t,it

isn

ot

po

ssib

leto

re-

move

met

alA

com

ple

tely

form

the

solv

ent.

At

any

acid

con

cen

trat

ion

,tr

aces

of

met

alA

wil

lre

mai

nin

the

solv

ent.

Inzo

ne

1o

fF

igu

re5

1,th

ew

ash

ing

zon

e,th

eac

idan

dth

ere

sto

fm

etal

Aar

ew

ash

edo

uto

fth

eso

lven

t.A

fter

this

step

,th

eso

lven

tis

com

ple

tely

reg

ener

ated

and

can

be

reu

sed

.

Gen

era

lF

low

Sh

eet.

Fig

ure

52

show

sa

gen

eral

flow

shee

to

fa

reac

tive

extr

acti

on

sys-

tem

. So

lven

tM

ake

-Up

.D

ue

toth

ep

oo

rd

istr

ibu

-ti

on

coef

fici

ent

of

the

acid

sever

alex

trac

tio

nst

eps

are

nee

ded

tolo

adth

eso

lven

tw

ith

suffi

-ci

ent

acid

tom

ake

extr

acti

on

of

the

met

als

po

s-si

ble

.In

the

giv

enex

amp

leth

eac

idco

mes

fro

mth

ein

itia

lso

luti

on

.T

oav

oid

loss

eso

fm

etal

A,

the

solv

ent

mu

stb

eco

mp

lete

lyfr

eeo

fA

.A

tth

elo

wac

idco

nce

ntr

atio

nin

the

firs

tst

eps

of

the

solv

ent

mak

e-u

pan

ym

etal

Ap

rese

nt

inth

eso

lven

tw

ill

be

re-e

xtr

acte

din

the

raffi

nat

e.R

eact

ive

Ext

ract

ion

.If

suffi

cien

tac

idis

pre

sen

tin

the

solv

ent,

bo

thm

etal

sw

ill

be

ex-

trac

ted

fro

mth

efe

edso

luti

on

.To

lim

itth

en

um

-b

ero

fst

eps

inth

eex

trac

tio

n,

con

cen

trat

edac

idis

add

ed.T

he

hig

hco

nce

ntr

atio

nis

nec

essa

ryfo

rth

em

etal

extr

acti

on

and

inth

eso

lven

tm

ake-

up

.S

olv

ent

Scr

ub

bin

g.

To

mak

esu

reth

atm

ost

of

met

alB

isw

ash

edo

utfr

om

the

solv

ent,

the

acid

solu

tio

nco

nta

inin

gm

etal

Aan

dac

idfr

om

the

solv

ent

was

hin

gst

epis

use

d,

soth

atw

est

ayin

the

extr

acti

on

zon

efo

rm

etal

A.T

he

seco

nd

com

-p

on

ent,

wit

ha

low

erd

istr

ibu

tio

nco

effi

cien

t,is

alre

ady

init

sst

rip

pin

gzo

ne

and

wil

lb

ew

ash

edo

uto

fth

eso

lven

t.T

oav

oid

loss

es,th

isst

ream

isse

nt

bac

kto

on

eo

fth

est

eps

inth

eex

trac

tio

n.

So

lven

tS

trip

pin

g.

Aft

ersc

rub

bin

g,

the

sol-

ven

tco

nta

ins

on

lym

etal

Aan

dac

id.U

sin

gw

ater

or

ad

ilu

teac

idso

luti

on

,th

ep

uri

fied

met

alA

can

now

be

re-e

xtr

acte

din

toa

wat

erp

has

e.S

olv

ent

Wa

shin

g.

Th

eso

lven

tm

ust

be

com

-p

lete

lyre

gen

erat

edb

efo

reit

can

be

recy

cled

toth

eso

lven

tm

ake-

up

.T

his

isd

on

eb

yad

din

gso

me

sup

ple

men

tary

was

hin

gst

eps

toth

esy

s-te

m.

Th

eam

ou

nt

of

wat

eris

cho

sen

acco

rdin

gto

the

req

uir

emen

tsin

the

scru

bb

eran

dth

en

um

-b

ero

fst

eps

isca

lcu

late

das

afu

nct

ion

of

that

amo

un

t.

5.3

.5.

Dil

uen

tsa

nd

Mo

difi

ers

Dil

uen

tsar

eu

sed

tore

du

ceth

eso

lven

tvis

cosi

ty,

imp

rove

ph

ase

sep

arat

ion

,an

dm

ost

of

all,

wh

enp

rop

erly

cho

sen

,to

red

uce

the

loss

of

solv

ent.

Th

eso

lub

ilit

yo

ftr

i-n

-bu

tylp

ho

sph

ate

(TB

P,o

ne

of

the

mo

stfr

equ

entl

yu

sed

extr

acta

nts

)in

pu

rew

ater

is4

20

mg

/Lat

roo

mte

mp

erat

ure

;a

50

%d

ilu

tio

no

fT

BP

inn

-hex

ane

low

ers

this

solu

bil

-it

yto

17

5m

g/L

.T

he

cho

ice

of

dil

uen

tis

ver

yim

po

rtan

t.H

igh

eram

ines

are

com

ple

tely

solu

-b

lein

alip

hat

icd

ilu

ents

.T

hei

rsa

lts,

how

ever

,ar

eo

nly

slig

htl

yso

lub

lein

the

sam

eso

lven

ts.

Th

eref

ore

itis

esse

nti

alto

test

the

solu

tio

ns

inal

lst

eps

of

the

pro

cess

.If

thir

d-p

has

efo

rma-

tio

no

ccu

rsin

on

eo

fth

est

eps,

the

dil

uen

tm

ust

be

chan

ged

or

am

od

ifier

isto

be

add

ed.

Th

ese

mo

difi

ers

are

no

rmal

lylo

ng

chai

nal

coh

ols

,mo

-noes

ters

of

poly

hydri

cal

cohols

,or

phosp

hat

e

Page 26: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

51

Fig

ure

52.

Gen

eral

flow

shee

tof

are

acti

ve

extr

acti

on

syst

em

este

rs.

Th

ese

mo

difi

ers

may

con

sid

erab

lyin

flu

-en

ceth

ek

inet

ics

of

the

extr

acti

on

.E

spec

iall

yin

the

extr

acti

on

of

cop

per

the

cho

ice

of

mo

difi

eris

ver

yim

po

rtan

t.T

he

dif

fere

nt

typ

eso

fso

lven

tar

eso

ldm

ixed

wit

ha

suit

able

mo

difi

erw

hic

hg

reat

lyen

han

ces

the

extr

acti

on

per

form

ance

of

the

solv

ent.

6.

Ref

eren

ces

1.

R.E

.T

reybal

:L

iquid

Ext

ract

ion,

McG

raw

-Hil

l,N

ewY

ork

–T

oro

nto

–L

ondon

1963.

2.

S.H

artl

and:

Counte

rC

urr

ent

Ext

ract

ion,

Per

gam

on

Pre

ss,O

xfo

rd1970.

3.

J.R

ydber

g,C

.M

usi

kas

,G

.R.C

hoppin

(eds.

):

Pri

nci

ple

sand

Pra

ctis

esof

Solv

ent

Ext

ract

ion,

M.D

ekker

,In

c.,N

ewY

ork

1992.

4.

C.H

anso

n:

Rec

ent

Adva

nce

sin

Liq

uid

–L

iquid

Ext

ract

ion,

Per

gam

on

Pre

ss,O

xfo

rd1971.

5.

T.C

.L

o,M

.H.I

.B

aird

,C

.H

anso

n(e

ds.

):

Handbook

of

Solv

ent

Ext

ract

ion,

Wil

ey-I

nte

rsci

ence

,N

ewY

ork

1983.

6.

J.D

.G

odfr

ey,M

.J.S

late

r(e

ds.

):

Liq

uid

–L

iquid

Ext

ract

ion

Equip

men

t,J.

Wil

ey&

Sons,

New

York

1994.

7.

J.W

isnia

k,A

.T

amir

:L

iquid

–L

iquid

Equil

ibri

um

and

Ext

ract

ion.A

Lit

eratu

re

sourc

eB

ook.

Physi

cal

Sci

ence

sD

ata,

7,P

artA

1980,P

artB

1981,P

hysi

cal

Sci

ence

sD

ata,

23,

Supple

men

t1

1985,E

lsev

ier,

Am

ster

dam

.

8.

Pro

ceed

ings

ISE

C’8

8,V

ernad

sky

Inst

itute

of

Geo

chem

istr

yan

dA

nal

yti

cal

Chem

istr

yof

the

US

SR

Aca

dem

yof

Sci

ence

s,4

vols

.,N

AU

KA

,

Mosc

ow

,1988.

9.

Pro

ceed

ings

ISE

C’9

0,C

hem

ical

Soci

ety

of

Japan

,E

lsev

ier,

New

York

1992.

10.

Pro

ceed

ings

ISE

C71,T

he

Hag

ue,

2vols

.,

Soci

ety

of

Chem

ical

Indust

ry,L

ondon

1971.

11.

Pro

ceed

ings

ISE

C74,L

yon,3

vols

.,S

oci

ety

of

Chem

ical

Indust

ry,L

ondon

1974.

12.

Pro

ceed

ings

ISE

C77,T

oro

nto

,2

vols

.,C

IMM

Spec

ial

Publi

cati

on,no.2

1,C

an.In

st.M

in.

Met

.,1979.

13.

Pro

ceed

ings

ISE

C80,L

iege,

3vols

.,A

ssocn

.

des

Ingen

ieurs

sort

isde

l’U

niv

ersi

tede

Lie

ge,

Lie

ge

1980.

14.

Pro

ceed

ings

ISE

C83,D

enver

AIC

hE

1983.

15.

Pro

ceed

ings

ISE

C86,M

unch

en,3

vols

.,

DE

CH

EM

A,F

rankfu

rt1986.

16.

Pro

ceed

ings

ISE

C’9

3,S

olv

ent

Extr

acti

on

in

the

Pro

cess

Indust

ries

,2

vols

.,E

lsev

ier,

New

York

1993.

17.

Pro

ceed

ings

ISE

C’9

6,V

alue

Addin

gT

hro

ugh

Solv

ent

Extr

acti

on,2

vols

.,T

he

Univ

ersi

tyof

Mel

bourn

e,P

arkvil

le,V

icto

ria,

Aust

rali

a1996.

18.

J.M

.S

ore

nse

n,W

.A

rlt:

“Liq

uid

–L

iquid

Equil

ibri

um

Dat

aC

oll

ecti

on,”

vol.

V,par

t

1–

3,D

EC

HE

MA

Chem

istr

yD

ata

Ser

.,

Fra

nkfu

rt1979.

19.

Lan

dolt

-Born

stei

n:

II2

c,S

pri

nger

Ver

lag,

Ber

lin

1980.

20.

O.M

adel

ung:

Landolt

-Born

stei

ndir

ecto

ry

dis

k1.1

,S

pri

nger

-Ver

lag,B

erli

n1994.

21.

A.S

eidel

,F.W

.L

inke:

“Solu

bil

itie

sof

Inorg

anic

and

Org

anic

Com

pounds,

”in

A.W

.

Fra

nci

s(e

d.)

:Ter

nary

Sys

tem

sSep

ara

ting

into

Tw

oL

iquid

Laye

rs,

van

Nors

tran

d,L

ondon

1952.

22.

A.W

.F

ranci

s:L

iquid

–L

iquid

Equil

ibri

a,

Wil

ey,N

ewY

ork

1963.

52

Liq

uid

–Liq

uid

Extr

action

23.

H.S

tephen

,T

.S

tephen

:Solu

bil

itie

sof

Inorg

anic

and

Org

anic

Com

pounds,

4vols

.,

Per

gam

on

Pre

ss,O

xfo

rd1964.

24.

F.R

uiz

,D

.P

rats

,A

.F.M

arci

lla:

“Liq

uid

–L

iquid

Extr

acti

on:

aG

raphic

al

Met

hod

for

Equil

ibri

um

Sta

ge

Cal

cula

tions

for

Quat

ernar

yS

yst

ems,

”F

luid

Phase

Equil

ib.

15

(1984)

no.3

,257

–265.

25.

W.R

uck

l,R

.M

arr:

“Mult

icom

ponen

t

Liq

uid

–L

iquid

Extr

acti

on,”

Ger

.C

hem

.E

ng.

(Engl.

Tra

nsl

.)8

(1985)

no.1

,27

–31.

26.

M.J

.H

ampe:

“Sel

ecti

on

of

Solv

ents

in

Liq

uid

–L

iquid

Extr

acti

on

Acc

ord

ing

to

Physi

co-C

hem

ical

Asp

ects

,”G

er.C

hem

.E

ng.

(Engl.

Tra

nsl

.)9

(1986)

no.4

,251

–263.

27.

Ull

mann,

4th

.,vol.

2,

550

–551.

28.

E.B

ender

,U

.B

lock

,“T

her

modynam

isch

e

Ber

echnung

der

Flu

ssig

-Flu

ssig

-Extr

akti

on,”

Ver

fahre

nst

echnik

(Mai

nz)

9(1

975)

no.3

,

106

–111.

29.

K.H

lavat

y:

“Corr

elat

ion

of

the

Bin

odal

Curv

e

ina

Ter

nar

yL

iquid

Mix

ture

wit

hO

ne

Pai

rof

Imm

isci

ble

Liq

uid

s,”

Coll

ect.

Czc

h.C

hem

.

Com

mun.

37

(1972)

4005

–4007.

30.

E.H

ecker

:“A

usw

ahl

von

Losu

ngsm

itte

lsyst

emen

zur

mult

ipli

kat

iven

Ver

teil

ung,”

Chim

ia8

(1954)

229

–236.

31.

C.M

.H

anso

n:

“The

Univ

ersa

lity

of

Solu

bil

ity

Par

amet

er,”

Ind.E

ng.C

hem

.P

rod.R

es.D

ev.

8

(1969)

no.1

,2

–11.

32.

C.R

eich

ardt,

K.D

imro

th:

“Losu

ngsm

itte

lund

empir

isch

eP

aram

eter

zur

Char

akte

risi

erung

ihre

rP

ola

rita

t,”

Fort

schr.

Chem

.F

ors

ch.

11

(1968)

no.1

,1

–73.

33.

R.A

nder

son,R

.C

ambio

,J.

M.P

rausn

itz:

“Physi

cal

and

Chem

ical

Forc

esin

Solv

ent

Sel

ecti

vit

yfo

rH

ydro

carb

ons,

”A

IChE

J.8

(1962)

66

–69.

34.

C.H

.D

eal,

E.L

.D

err:

“Sel

ecti

vit

yan

d

Solv

ency

inA

rom

atic

sR

ecover

y,”

Ind.E

ng.

Chem

.P

rod.R

es.D

ev.

3(1

964)

394

–399.

35.

R.A

.G

rieg

er,C

.A.E

cker

t:“S

olv

ent

Mix

ture

s

for

Sep

arat

ion

Pro

cess

es,”

Ind.E

ng.C

hem

.

Pro

d.R

es.D

ev.

6(1

967)

250

–255.

36.

E.M

ull

er,G

.Hohfe

ld:

“Aro

mat

enex

trak

tion

mit

Losu

ngsm

itte

lgem

isch

en,”

Erd

ol

Kohle

Erd

gas

Pet

roch

em.

24

(1971)

573

–578.

37.

D.T

assi

os:

“GL

CS

cree

ns

Extr

acti

on

Solv

ents

,”H

ydro

carb

on

Pro

cess

49

(1970)

no.7

,114

–118.

38.

I.M

ella

n:

Indust

rial

Solv

ents

Handbook,

Noyes

Dat

aC

orp

.,N

ewJe

rsey

1985.

39.

H.G

nam

m,W

.S

om

mer

:L

osu

ngsm

itte

lund

Wei

chm

ach

ungsm

itte

l,W

isse

nsc

haf

tlic

he

Ver

lags-

anst

alt,

Stu

ttgar

t1980.

40.

G.D

ave,

M.L

idm

an:

“Bio

logic

alan

d

Toxic

olo

gic

alE

ffec

tsof

Solv

ent

Extr

acti

on

Chem

ical

s,”

Hyd

rom

etall

urg

y3

(1978)

no.3

,

201

–216.

41.

R.B

erger

,W

.L

euck

el,D

.W

olf

,C

hem

.In

g.

Tec

h.

50

(1978)

no.7

,544

–545.

42.

R.M

arr,

G.H

usu

ng,F.M

ose

r,C

hem

.In

g.

Tec

h.

47

(1975)

no.5

,203.

43.

G.

A.R

ow

den

,M

.D

ille

y,C

.F.B

onney

,G

.A

.

Gil

let,

Lec

ture

atH

ydro

met

allu

rgy

81,

Man

ches

ter

1981.

44.

T.M

isek

,R

.B

erger

,J.

Sch

rote

r:Sta

ndard

Tes

t

Sys

tem

sfo

rL

iquid

Ext

ract

ion,

The

Inst

ituti

on

of

Chem

ical

Engin

eers

1985.

45.

D.N

iebuhr,

Ph.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Cla

ust

hal

(Fed

.R

ep.of

Ger

man

y)

1982.

46.

E.A

ufd

erhei

de,

Ph.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Cla

ust

hal

(Fed

.R

ep.of

Ger

man

y)

1985.

47.

W.P

ietz

sch,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en(F

ed.R

ep.G

erm

any)

1984.

48.

H.H

aver

land,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Cla

ust

hal

(Fed

.R

ep.of

Ger

man

y)

1988.

49.

K.H

.R

eiss

inger

,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Gra

z(A

ust

ria)

1985.

50.

R.B

erger

,K

.W

alte

r,C

hem

.E

ng.Sci

.40

(1985)

no.1

2,2175

–2184.

51.

H.Z

imm

erm

ann,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en(F

ed.R

ep.of

Ger

man

y)

1981.

52.

Th.P

ilhofe

r,C

hem

.In

g.Tec

h.

48

(1976)

no.3

,

237.

53.

E.B

ender

,R

.B

erger

,W

.L

euck

el,D

.W

olf

,

Chem

.In

g.Tec

h.

51

(1979)

no.3

,192

–199.

54.

R.B

erger

,L

ectu

reG

VC

annual

mee

ting,

Duss

eldorf

1981.

55.

J.K

om

asaw

a,J.

Ingham

,C

hem

.E

ng.Sci

.33

(1978)

no.3

,341

–347,no.4

,479

–485.

56.

Th.P

ilhofe

r,C

hem

.In

g.Tec

h.

51

(1979)

no.3

,

231.

57.

K.H

irsc

hm

ann,E

.B

lass

,G

er.C

hem

.E

ng.

7

(1984)

280

–287.

58.

G.W

agner

,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1995.

59.

B.H

oti

ng,A

.V

ogel

pohl,

Chem

.In

g.Tec

h.

68

(1981)

105

–112.

60.

H.W

.B

randt,

K.H

.R

eiss

inger

,J.

Sch

rote

r,

Ver

fahre

nst

echnik

9(1

975)

no.8,383

–387.

61.

G.D

ichtl

,T

.P

ilhofe

r,Ver

f.Tec

h.

15

(1981)

615

–617.

62.

H.R

ausc

her

,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1992.

Page 27: Ullmann's Encyclopedia of Industrial Chemistry.pdf

Liq

uid

–Liq

uid

Extr

action

53

63.

M.L

ore

nz,

Ph.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Cla

ust

hal

,1990.

64.

G.G

old

man

n,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1986.

65.

H.H

ufn

agl,

Ph.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1992.

66.

Th.P

ilhofe

r,D

.M

ewes

:

Sie

bboden

-Ext

rakt

ionsk

olo

nnen

,V

erla

g

Chem

ie,W

einhei

m–

New

York

1979.

67.

Th.P

ilhofe

r,G

er.C

hem

.E

ng.(E

ngl.

Tra

nsl

.)

2(1

979)

69

–76.

68.

G.Z

amponi,

Ph.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1996.

69.

K.H

irsc

hm

ann,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1984.

70.

K.H

.R

eiss

inger

R.M

arr,

Chem

.In

g.Tec

h.

58

(1986),

7,540

–547.

71.

J.D

.T

horn

ton,

Bri

t.C

hem

.E

ng.

32

(1958)

247

–251.

72.

A.E

.K

arr,

T.C

.L

o,

Pro

c.IS

EC

71.

73.

R.B

auer

,P

h.D

.T

hes

is,E

TH

Zuri

ch

(Sw

itze

rlan

d)

1976.

74.

Th.P

ilhofe

r,J.

Sch

rote

r,C

hem

.In

g.Tec

h.

56

(1984)

883

–890.

75.

W.B

acker

,J.

-P.S

chaf

er,J.

Sch

rote

r,C

hem

.

Ing.Tec

h.

63

(1991)

1008

–1011.

76.

E.B

lass

,W

.G

oet

tert

,M

.J.H

ampe:

“Sel

ecti

on

of

Extr

acto

rsan

dS

olv

ents

,”in

[6,C

hap

.18].

77.

I.W

agner

,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1999.

78.

R.B

erger

,C

hem

.In

g.Tec

h.

58

(1986)

no.6

,

499

–456.

79.

M.H

ensc

hke,

Ph.D

.T

hes

is,R

WT

HA

achen

,

1995.

80.

S.H

artl

and,S

.A.K

.Je

elan

iin

[6,C

hap

.13].

81.

Com

pute

rA

ided

Set

tler

Des

ign

“CA

SE

DY

Rau

scher

tV

erfa

hre

nst

echnik

Gm

bH

,P

ost

fach

20,D

-96347

Ste

inw

iese

n.

82.

A.K

riec

hbau

mer

,R

.M

arr,

Chem

.In

g.Tec

h.

55

(1983)

700

–707.

83.

W.R

om

mel

,W

.M

eon,E

.B

lass

,Sep

ara

t.Sci

.

Tec

hnol.

27

(1991)

129

–159.

84.

W.R

om

mel

,E

.B

lass

,W

.M

eon,

Chem

.

Engng.Sci

.47

(1992)

555

–564.

85.

W.M

eon,W

.R

om

mel

,E

.B

lass

,C

hem

.

Engng.Sci

.48

(1993)

159

–168.

86.

W.R

om

mel

,E

.B

lass

,W

.M

eon,

Chem

.

Engng.Sci

.48

(1993)

1735

–1743.

87.

F.R

ebel

ein,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1989.

88.

F.R

ebel

ein,E

.B

lass

,F

iltr

ati

on

&Sep

ara

tion

27

(1990)

360

–363.

89.

R.M

agie

ra,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1995.

90.

R.M

agie

ra,E

.B

lass

,F

iltr

ati

on

&Sep

ara

tion

34

(1997)

369

–376.

91.

S.H

off

man

n,P

h.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1999.

92.

Abw

asse

rtec

hnis

cher

Ver

ein

e.V

.(e

d.)

:

Indust

riea

bw

ass

er,

Ver

lag

Ern

st&

Sohn,

Ber

lin

1999.

93.

S.G

lanz,

Ph.D

.T

hes

is,T

echnis

che

Univ

ersi

tat

Munch

en,1998.

94.

S.G

lanz,

J.S

tich

lmai

rin

R.D

arto

n(e

d.)

:

“Dis

till

atio

nan

dA

bso

rpti

on

’97,”

Ichem

t,

Sym

p.Ser

.N

o.142,

1997.

95.

F.T

refn

y,E

rdol

Kohle

Erd

gas

Pet

roch

em.

23

(1970)

337

–340.

96.

E.C

inel

liet

al.,

Hyd

roca

rbon

Pro

cess

.51

(1972)

no.4

,337

–340.

97.

Hyd

roca

rbon

Pro

cess

.51

(1972)

no.4

,

141

–144.

98.

G.P

rece

sser

etal

.,O

ilG

as

J.Ju

ly16

(1973)

114

–118.

99.

Kru

pp

Kopper

s,H

ydro

carb

on

Pro

cess

.52

(1973)

no.4

,139

–141.

100.

Hyd

roca

rbon

Pro

cess

.(1

982)

182.

101.

G.M

.R

itce

y,A

.W.A

shbro

ok:

Solv

ent

Ext

ract

ion,

Par

t1,E

lsev

ier,

Am

ster

dam

1984.

102.

G.M

.R

itce

y,A

.W.A

shbro

ok:

Solv

ent

Ext

ract

ion,

Par

t2,E

lsev

ier,

Am

ster

dam

1979.

103.

Solv

ent

Ext

ract

ion

inM

etall

urg

ical

Pro

cess

es,

Inte

rnat

.S

ym

p.A

ntw

erpen

1972.

104.

W.W

.S

chulz

,J.

D.N

avra

til:

Sci

ence

and

Tec

hnolo

gy

of

Tri

buty

lP

hosp

hate

,vol.

I,C

RC

Pre

ss,B

oca

Rat

on,F

L1984.

105.

W.W

.S

chulz

,J.

D.N

avra

til,

A.S

.K

erte

s:

Sci

ence

and

Tec

hnolo

gy

of

Tri

buty

lP

hosp

hate

,

vol.

VI,

CR

CP

ress

,B

oca

Rat

on,F

L1991.

106.

A.K

.D

e,S

.M.K

hopar

,R

.A.C

hal

mer

s:

Solv

ent

Ext

ract

ion

of

Met

als

,V

anN

ost

rand

Rei

nhold

,L

ondon

1970.

107.

Bay

erA

G:

Ges

chaf

tsber

eich

Anorg

anis

che

Chem

ikal

ien,B

ayso

lvex

–T

BP

fur

die

Flu

ssig

-Flu

ssig

Extr

akti

on

1993.

108.

Bay

erA

G:

Ges

chaf

tsber

eich

Anorg

anis

che

Chem

ikal

ien,B

ayso

lvex

–D

ialk

an-p

hosp

hat

e

fur

die

Flu

ssig

-Flu

ssig

Extr

akti

on

1993.

109.

Bay

erA

G:

Ges

chaf

tsber

eich

Anorg

anis

che

Chem

ikal

ien,B

ayso

lvex

–D

2E

HPA

fur

die

Flu

ssig

-Flu

ssig

Extr

akti

on

1993.

110.

Bay

erA

G:

Ges

chaf

tsber

eich

Anorg

anis

che

Chem

ikal

lien

,B

ayso

lvex

–D

2E

HT

PA

fur

die

Flu

ssig

-Flu

ssig

Extr

akti

on

1993

111.

Bay

erA

G:

Ges

chaf

tsber

eich

Anorg

anis

che

Chem

ikal

ien,B

ayso

lven

tfo

ryour

Solv

ent-

extr

acti

on

1993.

112.

F.F

airb

roth

er:

The

Chem

istr

yof

Nio

biu

mand

Tanta

lum

,E

lsev

ier

Am

stra

d,L

ondon

–N

ew

York

1967,pp.8

–10.

54

Liq

uid

–Liq

uid

Extr

action

113.

Bay

erA

ntw

erpen

N.V

.,E

P0

396

790

A1,

1989.

114.

Bay

erA

ntw

erpen

N.V

.,D

E3

643

711

A1,

1986.

115.

Bay

erA

ntw

erpen

N.V

.,E

P638

515-A

2,1993.

116.

W.D

.Ja

mra

ck:

Rare

Met

al

Ext

ract

ion

by

Chem

ical

Engin

eeri

ng

Tec

hnolo

gy,

Per

gam

on

Pre

ss,O

xfo

rd1963.

117.

M.L

.W

ang,B

.L.L

iu:

“Extr

acti

on

Equil

ibri

um

of

Phen

ol

by

Sulp

huri

cA

cid

Sal

ts

of

Tri

isooct

yla

min

e,”

Chem

.E

ng.C

om

m.

156

(1996)

131

–146.

118.

Bay

erA

ntw

erpen

N.V

.,D

E3

524

053

A1,

1985.