Result Mass Exp 4

OBJECTIVE 

Operate a Liquid – Liquid Extraction Experiment using a Pulsed Column Liquid –  Liquid Extraction Unit.



To determine the height equivalent theoretical plates (HETP !or column "# using equilateral triangular diagram.



To investigate investigate the e!!ect o! the pulsation stro$e on the HETP.

SUMMARY

% Liquid Liquid&Li &Liqui quid d Extrac Extractio tion n (LLE (LLE method method o! separa separati tion on usuall usuall# # done 'hen 'hen separa separatio tion n o!  components o! a liquid mixture cannot "e done "# using distillation process. There!ore this LLE method 'ill "e use to separate the liquid mixture. n this experiment) the stud# 'ill involves 'ith the operations o! LLE "# using a pulsed column LLE unit in order to determine the height equivalent theoretical plates (HETP !or column "# using the equilateral triangular diagram and at the same time to investigate the e!!ect pulsation pu lsation stro$e on the HETP. The experiment 'as done  "# having a !eed !lo's containing o! solvent (Toluene (Toluene in light phase and *eed (%cetone&+ater  (%cetone&+ater  mixture in heav# phase. The outlet !lo's 'ill contain t'o di!!erent outlet 'hich 'ill "e an extract containing the toluene in rich phase and the ra!!inate containing 'ith 'ater also in rich  phase. The product o"tained 'hich the extract is as !or in this experiment) the toluene 'ill "e anal#,ed "# reading its - in order to con!irm i! it has the correct - !or toluene. The separation o! the liquid generall# 'as "ased on their selectivit# (separation !actor) distri"ution coe!!icient) solvent insolu"ilit#) densit# and more. The experiment can "e concluded as a success i! the theoretical stages calculated in the triangular plot is "et'een  to / stages. n this experiment) the  plotted triangular sho's a theoretical stages to achieve the !inal ra!!inate and extract compositions has  stages) there!ore the experiment 'as a success.%s the pulsation stro$e $ept constant the LLE experiment per!ormance 'ere at its optimum per!ormance. Theoreticall# it 'as said that 'hen the pulsation intensit# or stro$e increase the per!ormance o! column 'ill also increase.

INTRODUCTION & THEORY

*irstl#) must prepare 01 litres o! /1't 2 mixture o! %cetone in +ater "# mixing appropriate quantities o! the %cetone in distilled 'ater. Then) Prepare 01 litres o! 3olvent that Pure Toluene. 4ext) The "ottom product contains the +ater -ich Phase (-a!!inate  'hile the top  product contains the Toluene -ich Phase ( Extract  'ere collected to ma$e samples in 51 ml o!  -a!!inate and 51 ml sample o! Extract .%!ter) -ecord the -e!ractive ndex o! "oth samples "# using re!ractive index measurement.

Extraction is the pulling out o! something !rom something else and separation "# liquid& liquid extraction can "e de!ined as the selective removal o! one or more components either !rom a homogeneous liquid mixture or !rom a solution) using a second liquid or solvent) 'hich is  partiall# or 'holl# immisci"le 'ith the !irst (Thornton. n liquid&liquid extraction) t'o phases must "e "rought into contact to permit trans!er o! material and then "e separated. Extraction equipment ma# "e operated continuous and the extract is the la#er o! solvent plus extracted solute also the ra!!inate is the la#er !rom 'hich solute has "een removed. The extract ma# "e lighter or heavier than the ra!!inate) and so the extract ma# "e sho'n coming !rom top o! the equipment in some cases and !rom the "ottom in others (6avin)0117.

+hereas distillation a!!ects a separation "# utili,ing the di!!ering volatilities o! the components o! a mixture) liquid&liquid extraction ma$es use o! the di!!erent extent to 'hich the components can partition into a second immisci"le solvent. This propert# is !requentl# characteristic o! the chemical t#pe so that entire classes o! compounds ma# "e extracted i!  desired. n general) extraction is applied 'hen the materials to "e extracted are heat&sensitive or  nonvolatile and 'hen distillation 'ould "e inappropriate "ecause components are close&"oiling) have poor relative volatilities or !orm a,eotropes (Heit#)0158. The simplest extraction operation is single&contact "atch extraction in 'hich the initial !eed solution is agitated 'ith a suita"le solvent) allo'ed to separate into t'o phases a!ter 'hich the solvent containing the extracted solute is decanted. *inal settling or phase separation is achieved under gravit# at one end o! the column "# allo'ing an adequate settling volume !or 

complete phase disengagement. %n# one extraction operation gives rise to t'o product streams9 the extracted !eed solution) more usuall# termed the ra!!inate phase) and the solvent containing extracted solute termed the extract phase (Perr#)5:;.

*igure 5.5 Pulsed extraction. *or this experiment) the

column liquid&liquid extraction

process   using

tertiar# s#stem (acetone&'ater&toluene. *or *eed
*igure 5.0 equilateral triangular diagram. Equilateral triangular coordinates are o!ten used to present the equili"rium data !or a three&component s#stem) since there are three axes. Each o! the three corners represents a pure component  A)  B)

C .

The point 5 represent a mixture o!  A)  B)

C .

the point 5 to the "ase  AB represent the mass !raction o!  X C   o!

the perpendicular distance !rom

C   mixture

at point 5) the distance

to the "ase CB the mass !raction o!  X  A o!  A) and the distance to "ase  AC  the mass !raction  X  B o!   B.

% theoretical plate in man# separation processes is a h#pothetical ,one or stage in 'hich t'o phases) such as the liquid and vapor phases o! a su"stance) esta"lish an equili"rium 'ith each other. The  per!ormance o! man# separation processes depends on having a series o! equili"rium stages and is enhanced "# providing more such stages. %n# ph#sical device that provides good contact "et'een the vapor and liquid phases. Ph#sical plate is rarel# a 5112 e!!icient equili"rium stage) the num"er o!  actual plates is more than the required theoretical plates (>ister)5::0.

RESULTS

*eed -

5.1

*eed Composition

1./ TABLE 1: Data Tabulation

*eed

3olvent

3olvent

Pulsation

!lo'rate

!lo'rate

to *eed

stro$e

ratio

(mm

(L?hr    (L?hr   

-a!!inate ('ater rich phase  Time -e!ractive (min   ndex  

3olute (%cetone

Extract (Toluene rich phase -e!ractive ndex  

3olute (%cetone

Composition

Composition

('t 2

('t 2

7.77

7.77

5

/

/

5./8

1.0:

5.80

 

1.@

7.77

7.77

5

/

51

5.8/

1.@

5.@8

 

1.08

7.77

7.77

5

/

5/

5.8@

1.@

5.8

 

1.8/

7.77

7.77

5

/

01

5.8/

1.@

5.8@

 

1.@

APPENDI

A!!"n#i$ B

TABLE %: Calibation Cu'" Data (o Tolu"n" Ri)* P*a+" A'"a," - ."i,*t /A)"ton"0

R"(&a)ti'" In#"$ /A'"&a,"0

1.51

5.7/8

1.5:;

5.@:

1.0

5.81

1./0:

5.57

1.@17

5.11@

1.@1

5.8@;7

I2URE 1: Tolu"n" Ri)* P*a+" Calibation Cu'"

A!!"n#i$ C

TABLE 3: E4uilibiu5 #ata Bino#ial6 Solubilit7 Data (o A)"ton"8Tolu"n"8.at" S7+t"5 Tolu"n" Ri)* P*a+"

.at" Ri)* P*a+"

A)"ton"

Tolu"n"

A)"ton"

Tolu"n"

1.1:7:

1.;77;

1.@8:8

1.58:

1.5:;

1.77@1

1.@85

1.5@5

1./0

1./;;

1.1@/:

1./081

1.08

1./550

1.1851

1.@1@7

1.805

1.8:@/

1.158;

1.@8/;

1.58;:

1.5::

1.1501

 

 

1.55:;

TABLE 9: Data (o Solut" Di+tibution /Ti" lin"+0 H"a'7 P*a+" /.at"& Ri)*0

Li,*t P*a+" /Tolu"n" Ri)*0

A)"ton" ."i,*t Co5!o+ition

1./57

1.@:;

1.1;

1.///

1.807

1./1

1.815

1.00

1.05

1.8:

1.1:@

1.80/

ANALYSIS AND DISCUSSION

%s mention in the o"Aective o! the experiment) the main purpose o! running this experiment 'as to operate a Liquid&Liquid Extraction (LLE "# using Pulsed Column LLE unit. The experiment 'as done also to determine the height equivalent theoretical pates (HETP !or the column "# using equilateral triangular diagram. *urthermore) the experiment also run to investigate the e!!ect o! the pulsation stro$e on the HETP. This separation method o! solvent extraction or usuall# $no'n as the LLE involves 'ith the separation o! compounds "ased on their relative solu"ilit# "et'een t'o distinct immisci"le liquids or almost immisci"le.

n this experiment 'here it involves 'ith the operation o! LLE "# using the pulsed column) the separation involves 'ith !eed !lo's divided into t'o 'hich 'as solvent and !eed. The solvent 'ill "e the toluene (Light Phase and the !eed 'ill "e a mixture o! 'ater and acetone (Heav# Phase. The outlet !lo's also divide into t'o 'hich contain o! extract and ra!!inate 'here the extract 'ill the toluene in rich phase and the ra!!inate 'ill "e the 'ater in rich phase.

The re!ractive index (- o! the outlet !lo's 'as determined "# using a digital re!ract meter  and ta"ulated in ta"le 5 "# ta$ing sample ever# / minutes until it reach 01 minutes. n order to determine the solute acetone composition (3%C in "oth outlet !lo's) a cali"ration curve need to  "e plotted as sho'n in !igure 5 "# using the in!ormation in ta"le 0 'ith - verses %verage 'eight / o! acetone. Using the - o! outlet !lo's) re!er the - in the cali"ration curve to determine the 3%C. n ta"le 5) the 3%C !or ra!!inate sho's that as the re!ractive index decrease the 3%C 'ill increase and at some time it 'ill reach a constant value 'hile !or the extract) the - should "e increasing and the 3%C 'ill decrease.

The t'o outlet !lo's - reading 'here in ra!!inate 'hich 'as a 'ater rich phase it should have a - reading o! 'ater o! 5.8) the !irst sample at / min) the samples rather sho's a higher - reading o! 5./8 'hich 'as nearer to toluene - o! 5.: "ut starting !rom sample t'o at 51 min to 01 min the - reading sho's a correct reading that sho's it 'as a 'ater rich phase. The Extract 'hich 'ill "e a toluene rich phase sho's a reading - reading o! 'ater in the !irst /

minutes and it recorded a toluene - !or samples 51 min and 5/ min "ut the - reading turn "ac$  into 'ater -. The - reading o! toluene rich phase should "e sho'ing more o! toluene - reading as the times increase.

n toluene rich phase) the error pointed 'hich 'as the last - reading) instead o! giving a toluene - reading) the digital re!ract meter read a 'ater - 'hich cannot "e happening since it supposed to "e in toluene extract. The error ma#"e due to the mixture o! 'ater and toluene over!lo'ing at the same place. +here the over!lo's !or toluene contain some 'ater or it can "e a lea$ed. Other reason !or this error ma#"e a!!ected 'hile ta$ing the - reading o! samples 'here the experimenter did not rinsed o!! the re!ract meter "e!ore ta$ing other samples -. *urthermore) the error might also contri"uted "# con!usion 'here the experimenter ta$e the same samples to examined the - reading 'here instead o! reading the toluene -) the experimenter ta$es the 'ater -) this con!usion ma#"e contri"uted "# the transparenc# o! the samples as 'ater and toluene has the same transparenc#.

The theoretical stages to achieve !inal ra!!inate and extract compositions 'as determined "#  plotting the *eed (*) 3olvent (3) -a!!inate (-) Extract (E and *eed and solvent mixture (B as sho'n in !igure 0 the triangular plot. The plotting 'as done "# re!erring to the appendix given. %!ter the plotting has "een done) the - located 'here all the operating lines meet. %ccording to !igure 0) the theoretical stages 'as calculated "# counting the lines insides the E&*&-&3 quadrilateral 'here onl# the lines that has the t'o dotted lines inside o! the quadrilateral are counted as the theoretical stages. %s sho'n in !igure 0) the theoretical stages to achieve the !inal ra!!inate and extract compositions sho's that it needs  stages onl#.

The trans!er rate o! solute to solvent phase can "e a!!ected "# a high distri"ution ratio o! the solute o! interest "et'een the t'o liquid phases. The attainment o! selectivit# in an extraction also important) 'here other !actors that contri"ute to the trans!er rate o! solute depends on the solvent choice) selectivit# (separation !actor) distri"ution coe!!icient) solvent insolu"ilit#) densit# and more.

Theoreticall#) the e!!ect o! pulsation intensit# on the overall trans!er rate !or toluene&'ater& acetone decreases as the pulsation intensit# increase) "ut in this experiment) the pulsation !requenc# or stro$e 'as set to "e constant at / mm) and it sho's that the column per!ormance increased or it 'as at its optimum per!ormance.M; Toab< J; Sa(#ai an# A; 2*a"5i< %=1=>;

CONCLUSION

%s a conclusion) this experiment 'as a success) 'here it meet the requirements o! the experiment 'hich 'as the o"Aectives o! the experiment. The operation o! the Liquid&Liquid Extraction (LLE experiment 'as a success 'here the HETP and also the e!!ect o! pulsation stro$e on the HETP can "e determined. +hile running the experiment) the - reading !or the outlet !lo's !or ra!!inate 'as a success 'here it is in a 'ater rich phase "ut !or the outlet !lo's !or extract that supposed to reach toluene rich phase sho's an error - reading !or the last samples as it sho's a 'ater - reading. This error ma#"e due to the instrument !ailure 'hich there ma# "e some lea$ed or the 'ater !ollo's the toluene over!lo's. Other reason ma# "e due to the experimenter con!usion "# ta$ing the 'ater - reading !or toluene in con!usion o! the outlet !lo's color transparenc#. Theoreticall# it is mention that the theoretical stages to achieve !inal ra!!inate and extract compositions are in "et'een  to / stages. n this experiment) the theoretical stages o"tain 'as  so it can "e concluded that this experiment 'as a success.

RECOMMENDATIONS

n this experiment) some error 'as o"tain 'hile running the experiment. n order to avoid this error to "e happening in the !uture) the reading o! samples re!ractive index (- should "e done "# t'o person to "e more accurate. +here one person 'ill ta$e the ra!!inate - and the other person ta$e the extract -. n the !uture) the LLE experiment should "e using a various $ind o! solvent and solute in other to compare 'hich solvent and solute are more e!!icient. The - reading instrument also can "e varies and di!!erentiate) 'here other - instrument can "e used to determine the - 'hich is the re!ractometer.

REERENCE

B. Tora"&Bostaedi) D. 3a!dari and %. 6haemi) (Dune 0151. Bass Trans!er Coe!!icients in Pulsed  per!orated&plate extraction columns. OnlineF. %ccessed 8&1&015@F. %vaila"le !rom +orld +ide +e"9 http9??'''.scielo."r?scielo.phpGscriptsciIarttextJpid3151&@@800151111011118

6avin To'ler and - > 3innott (0117. Chemical Engineering Kesign9 Principles) Practice and Economics o! Plant and Process Kesign. =utter'orth&Heinemann. Heit#. (0158.Kesign Principles !or Liquid&Liquid Extraction. OnlineF. %ccesses 8??015@F. %vaila"le !rom 'orld'ide 'e"9 http9??'''.aiche.org?resources?pu"lications?cep?015/?novem"er?design&principles&liquid& liquid& extraction >ister) H.. (5::0. Kistillation Kesign (5st ed.. Bc6ra'&Hill. Perr#) -o"ert H. and 6reen) Kon +. (5:;. Perr#Ms Chemical EngineersM Hand"oo$ (@th ed.. Bc6ra'&Hill. Thornton) D.K. (015@. Extraction liquid&liquid. OnlineF. %ccesses 8??015@F. %vaila"le !rom 'orld'ide 'e"9 http9??'''.thermopedia.com?content?7/0?