Acetic Acid, Diacetin & Triacetin

Acetic Acid, Diacetin & Triacetin

By: S. Afsari

Quaternary Solubility of

in Supercritical Carbon Dioxide

Superadvisor: Dr. Ghaziaskar

Contents

o Introduction o Supercritical Regiono Supercritical fluids and CO2 as a SF.o Advantages of Supercritical Sys.o Factors effecting on supercritical solubilityo Apparatuso SFE systemso ACAC and Glycerol Acetyls in supercritical

systemso Solubility measurements in ScCO2 and possible

separation techniques

Why GlycerolAcetyls?

Transesterification of vegetable oils

+ 3 HOCH3

NaOH or KOH Catalyst

+

Glycerol acetylation

Diacetin Triacetin

Structure

Formula

Molecular weight 176.17

Melting point -30 ºC

Boiling point 259 ºC

253 OH(CH3COO)HC

Structure

Formula

Molecular weight 176.17

Melting point -30 ºC

Boiling point 259 ºC

353 (CH3COO)HC

http://en.wikipedia.org/wiki/File:Triacetin.svg

Supercritical Region

C

Tscco21

Supercritical FluidsSc Fluid Critical T

(ºC )Critical P

(bar)Critical ρ )g/mL(

(CO2) 1.31 8.73 466.0

(H2O) 0.374 6.220 3220.

(N2O) 4.36 5.52 4530.

(NH3) .4132 2.113 2350.

(C4H10) .6196 7.33 2320.

(SF6) 5.45 3.37 7370.

(Xe) .616 3.58 0991.

(CH2F2) 1.78 8.57 4240.

(CH4) 6.82- 0.46 1630.

(C3H8) 7.96 5.42 2200.

(C2H6O) 9.126 .054 2420.

(C6H6) 5.289 2.49 0030.

1) Low critical T2)Cheap3) available3) Inexplosive4) Nontoxic

ХХХ

CO2 Phase Diagram

Gas likeliquid like

Ability of controlling Solubility

High diffusion

Low viscosity

Easy separation of solvent from solute

Factors Effecting Solubility in Supercritical Fluids

Pressure

Temperature

Solute StructureSolvent Structure

Sample MatrixHildebrand Parameter:

r(Liq)r1/2

c /ρρ1.25Pδ

cr ρ/ρρ

Cr(Liq) 2.66ρρ ρ0.47Pδ 1/2

c


Pressure

Temperature


Sample Matrix

0.000

0.200

0.400

0.600

0.800

1.000

1.200

60 80 100 120 140 160 180 200

Pressure

y X

100

40 C 60 C

40ºC

60ºC


Pressure

Temperature


Sample Matrix

1)Solute Structure

2)Solute Vapor pressure

3)Solute-Solvent interactions


Pressure

Temperature


Sample Matrix

ScF Density(g/ml)

Solubility (mole fraction X 100) Supercritical Fluid

0.39 4.750.81 2.420.94 1.17

3CHF2CO62HC

Naphthalene

http://fr.wikipedia.org/wiki/Fichier:Naphthalene.svg


Pressure

Temperature


Sample Matrix1)Chemical

properties

2)Physical properties

Apparatus

Gas Meter

Introduction

2 port cylindrical cells

Apparatus

Gas Meter

Back Pressure Adjuster

Apparatus

Gas Meter

Sampling Collection solvent

Solute

Apparatus

Gas Meter

SFE Systems

• On-line

• Off-line

Different possible analyzing methods

Simple & practical separationHigher sensitivity

Lower repeatability

Higher repeatabilityLower solvent consumptionLower time consuming procedure

Fluctuations in flow rate

Solubility

Gas meter: V, T

Weighting GC

RTPVn

2CO 2COn

Analyten Analyten

Mole fraction:

g/L in CO2

CO2

solute

VWS

2COothersolute

solute

nnnny

Sample:

Solvent: Et-OH

ACAC

DAG

TAG

:89%

:9%

:6%

0

0.5

1

1.5

2

2.5

3

3.5

100 120 140 160 180 200

experimantal

refrence

Pressure )bar( Solubility of 1-Decanol )y×100(refrence experimental

110 1.05 1.07120 1.183 1.15160 1.652 1.587180 1.882 3.17

y×10

0

Pressure (bar)

System Stability Checking

0

10

20

30

40

50

60

70

0 0.5 1 1.5 2 2.5 3 3.5

ACAC

TA

DA

CO2 Volume (L)

W (m

g)Purge Test

Effective Parameters on Solubility in ScCO2

TemperaturePressure

Flow RateWeight of sample

Weight of Sample

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

0 2 4 6 8 10 12 14 16 18 20

6.0 g

3.0 g

1.5 g

0.8 g

ACAC

y×10

0

CO2 Volume (L)

Weight of Sample

0.001.002.003.004.005.006.007.008.009.00

10.00

0 2 4 6 8 10 12 14 16 18 20 22

6.0 g

3.0 g

1.5 g

0.8 g

TAG

y×10

0

CO2 Volume (L)

Weight of Sample

0.001.002.003.004.005.006.007.008.009.00

10.00

0 2 4 6 8 10 12 14 16 18 20 22

6.0 g

3.0 g

1.5 g

0.8 g

DAG

y×10

0

CO2 Volume (L)


TemperaturePressure

Flow RateWeight of sample

Weight of Sample

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

0 2 4 6 8 10 12 14 16 18 20

6.0 g

3.0 g

1.5 g

0.8 g

y×10

0

CO2 Volume (L)


TemperaturePressure

Flow RateWeight of sampleӨ (ºC): 30,40,60,75

P (bar): 70,100,120,140,160,180

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

60 80 100 120 140 160 180 200

y×10

0

Pressure (bar)

40ºC

60ºC

75ºC

ACAC

TAG

0.00

0.20

0.40

0.60

0.80

1.00

1.20

60 80 100 120 140 160 180 200

Ө: 40ºC, P: 70 barӨ: 60ºC, P: 70 barӨ: 75ºC, P: 70 barӨ: 75ºC, P: 100 bar

mSSC blm

m

blblm ksSS

y×10

0

Pressure )bar(

40ºC

60ºC

75ºC

DAG

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

60 80 100 120 140 160 180 200

Ө: 40ºC, P: 70 barӨ: 60ºC, P: 70 barӨ: 60ºC, P: 100 barӨ: 75ºC, P: 70 barӨ: 75ºC, P: 100 bar

y×10

0

Pressure )bar(

40ºC

60ºC

75ºC

SeparationACAC, DAG, TAG

100

1

*

n

ii

j

m

m

86

88

90

92

94

96

98

100

102

60 80 100 120 140 160 180 200

75 C

60 C

40 C

α%

Pressure )bar(

Separation of ACAC

Expanded CO2)L(

Elapsed time)min(

Extracted ACAC)mg(

Extracted ACAC)%(

5 28 22.12 2.510 56 88.72 1020 111 192.13 2130 167 294.86 3340 222 339.06 3750 278 341.28 38

Ө: 60ºCP: 70 bar

Separation of ACAC

Expanded CO2)L(

Elapsed time)min(

Extracted ACAC)mg(

Extracted ACAC)%(

5 28 22.12 2.510 56 88.72 1020 111 192.13 2130 167 294.86 3340 222 339.06 3750 278 341.28 38

Ө: 60ºCP: 70 bar

Et-OH

ACAC

n-hexanol

Separation of ACAC

Expanded CO2)L(

Elapsed time)min(

Extracted ACAC)mg(

Extracted ACAC)%(

5 28 171.78 2.510 56 473.21 1015 83 664.73 4920 111 761.08 56

Ө: 75ºCP: 100 bar

SeparationTAG & DAG

Ө: 40ºC, P: 70 barӨ: 60ºC, P: 70 barӨ: 75ºC, P: 70 barӨ: 75ºC, P: 100 bar

TAG

Ө: 40ºC, P: 70 barӨ: 60ºC, P: 70 barӨ: 60ºC, P: 100 barӨ: 75ºC, P: 70 barӨ: 75ºC, P: 100 bar

DAG

Ө=60 ºC, P=70 bar ACACӨ=60 ºC, P=100 bar TAG

1)Incomplete extraction

2)Low efficiency

Separation of ACAC under Subcritical Situation

?


Pressure



properties


Binary and Quaternary Solubility of Acetic Acid

0

2

4

6

8

10

12

14

16

60 80 100 120 140 160 180 200

y×10

0

Pressure )bar(

Binary

Quaternary

Solvent Attributes of ScCO2

CO2C

O

O CCH3

OH

OC

CH3

OH

O

http://en.wikipedia.org/wiki/File:Triacetin.svg


Pressure



properties


0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

60 80 100 120 140 160 180 200

Diacetin

Triacetin

y×10

0

Pressure )bar(

Ө= 40ºC


Pressure



properties


0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

60 80 100 120 140 160 180 200

Diacetin

Triacetin

Ө= 75ºC

y×10

0

Pressure )bar(

Bartle Equation

refref

ρρcTba

PyPln

1.0barPref 3ref 700Kg.mρ

y: Solubility (mole fraction)T: temperature (K)ρ: CO2 density in P & T ( )3Kg.m

y xb m

Experimental Solubility Correlation

ACACDAGTAGӨ: 40ºC, 75ºC P: 100-180 bar

Ө: 60ºCP: 100-180 bar0

100

200

300

400

500

600

700

800

900

60 70 80 90 100 110 120 130 140 150 160 170 180 190

40 C

60 C

75 C

ρ )g

/L(

Pressure )bar(


ACAC

y = 0.0044x + 0.4412R2 = 0.9758

y = 0.004x + 1.4445R2 = 0.9925

y = 0.0044x + 2.3226R2 = 0.9727

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

-500 -400 -300 -200 -100 0 100 200

75 C

60 C

40 C

Ln(y

P/Pre

f)

ρ-ρref


ACAC44120

15313.

.

ba

3226215348

..

ba

y=0.0044x+1.56470.0044-5860.329919.1553Line Eq.c ( )b (K)a 13.Kgm y = 0.0044x + 1.5647

R2 = 1y = 0.004x + 1.4445

R2 = 0.9925

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

-300 -250 -200 -150 -100 -50 0

Calculated

Experimantal

Ln(y

P/Pr

ef)

ρ-ρref


4412015313

..

ba

3226215348

..

ba

%*%exp,

exp., 1001

ti

ticalcdi

xxx

nAARD

y=0.0044x+1.56470.0044-5860.329919.1553Line Eq.c ( )b (K)a 13.Kgm

ACAC

8.0y=0.0048x-1.54190.0048-5775.715.7948

AARD%Line Eq.c ( )

b (K)a 13.Kgm

DAG

12.0y=0.0049x-1.72700.0049-5307.1495

14.2032

AARD%Line Eq.c ( )

b (K)a 13.Kgm

TAG

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Acetic Acid, Diacetin & Triacetin