Pressure [bar]

2003년 10월 13일

서울대학교 응용화학부 열물성연구실 권소영, 배 원, 김화용

초임계 이산화 탄소 및 고분자합성을 위한 모노머의 상평형 연구

3. PVP-NVP-scCO ₂ 계의 상평형

Materials Materials

Carbon dioxide

[124-38-9]

(min. 99.99%)

From Korea Industrial Gases

Ethyl Alcohol

[64-17-5]

(min. 99.9%) From Hayman Limited

N-vinyl pyrrolidone(NVP)

[88-12-0]

(min. 99%) From Aldrich

Polyvinylpyrrolidone(PVP)

[9003-39-8]

Mw = 2,500 from Polyscience

Mw = 10,000, 29,000, 55,000 From Aldrich

N C

C H

H O

H

N C C

n O

Figure 1. Schematic Diagram of the experimental apparatus

Experimental Apparatus Experimental Apparatus

1. Camera 2. Light source 3. Borescope 4. Thermocouple 5. View cell

6. Magnetic stirrer 7. Air bath

8. Digital thermometer

9. Digital pressure transducer 10. Pressure gauge

11. Hand pump

12. Computer monitor

13. Trap

Mole fraction of CO

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Pressure [bar]

30 40 50 60 70 80 90 100

314.5 K Jennings et al.[1]

325.2 K Jennings et al.[1]

315.2 K This work 325.9 K This Work

Phase behavior of CO

₂

Consistency Test

Consistency Test

Mole fraction of CO

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

P ressure(b ar)

0 20 40 60 80 100 120 140 160 180 200

324.8K 335.1K 345.5K 355.8K

CO ₂ +NVP System CO ₂ +NVP System

Phase behavior of CO

₂

Vapor +Liquid Fluid

) (

) (

) (

b V

b b

V V

T a b

V P RT

− +

− +

= −

∑∑

=

i j

ij j i

m x x a

a

) 1

( _ij

jj ii

ij a a k

a = −

∑∑

=

i j

ij j i

m x x b

b

) 1

2 ( ) (

ij jj

ii ij

b

b b + − η

=

Correlation of CO ₂ -NVP System Correlation of CO ₂ -NVP System

ƒ Peng – Robinson Equation of State [2]

ƒ van der Waals 1-fluid mixing rule

Two adjustable parameters !

ƒ Object function(OBF)

2

∑ _ ^





 



 −

= ^N

i

cal

P P OBF P

exp exp

ƒ Root Mean Squared relative Deviation(RMSD)

100

* (%) ND RMSD = OBF

ƒ Optimization Algorithm

Marquardt algorithm[3]

Correlation of CO ₂ -NVP System

Correlation of CO ₂ -NVP System

0.420 ^**

42.7 ^* 640.6 ^*

NVP

0.239 ^[4]

73.8 ^[4]

304.1 ^[4]

CO ₂

ω P _c [bar]

T _c [K]

Component

* Estimated with Joback method [5]

∑ ^∆

+

= _{i bi}

b K n

T ( ) 198 . 2

2

]

) (

) (

9651 . 0 584 . 0 [ )

( ⁼

⁺ ∑

^∆

⁻ ∑

^∆

c

K T n n

T

∑ ^{∆ −}

− +

= [ 0 . 113 0 . 0032 ] ² )

( _{atoms i P}

c bar N n

P

C C

N C C

C C

O

H H

H H

H H

H H H

** Estimated with Lee-Kesler method [5]

β ω = α

6 1 1 . 28862 ln 0 . 169347 09648

. 6 97214 .

5

ln θ θ θ

α = − P _c − + ⁻ + −

6 1 13 . 4721 ln 0 . 43577 6875

. 15 2518 .

15 θ θ θ

β = − ⁻ − +

c b

T

= T θ

Critical constants and acentric factors

Critical constants and acentric factors

Mole fraction of CO₂

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Pressure(bar)

0 20 40 60 80 100 120 140 160 180 200

324.8K 335.1K 345.5K 355.8K

Mole fraction of CO₂

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Pressure(bar)

0 20 40 60 80 100 120 140 160 180 200

324.8K 335.1K 345.5K 355.8K

2.59 (%)

0.0136 0.0549,

=

−

=

= RMSD

k _ij η _ij 0.0

0.0, =

= _ij

k ij η

Correlation of CO ₂ -NVP System

Correlation of CO ₂ -NVP System

CO ₂ -PVP System CO ₂ -PVP System

Temperature(

C)

0 20 40 60 80 100 120 140 160 180 200

P res su re (b ar )

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

No one phase region was observed in this area !

?

The solubility of PVP in scCO

₂

very low !

Temperature(

C)

40 60 80 100 120 140 160 180 200

P ressure(bar )

0 500 1000 1500 2000

NVP 29.4 wt%

NVP 34.3 wt%

NVP 44.4 wt%

PVP-NVP-CO ₂ system PVP-NVP-CO ₂ system

Temperature(

C)

40 60 80 100 120 140 160 180 200

Pressure(bar)

0 500 1000 1500 2000 2500

NVP 24.8 wt%

NVP 29.6 wt%

NVP 34.6 wt%

PVP Mw = 2,500 PVP Mw = 10,000

Fluid Fluid

Liquid +Liquid Liquid +Liquid

Increasing NVP content

Increasing NVP content

Temperature(

C)

40 60 80 100 120 140 160 180 200

Pressure(bar)

0 500 1000 1500 2000

NVP 29.7 wt%

NVP 32.1 wt%

NVP 36.6 wt%

PVP-NVP-CO ₂ system PVP-NVP-CO ₂ system

Temperature(

C)

40 60 80 100 120 140 160 180 200

Pressure(bar)

0 500 1000 1500 2000

NVP 30.3 wt%

NVP 36.6 wt%

PVP Mw = 29,000 PVP Mw = 55,000

Fluid Fluid

Liquid +Liquid Liquid +Liquid

Increasing NVP content

Increasing NVP content

Temperature(

C)

40 60 80 100 120 140 160 180 200

P re ssu re (ba r)

0 500 1000 1500 2000

PVP (Mw= 2,500), NVP 29.6wt%

PVP (Mw=10,000), NVP 29.4wt%

PVP (Mw= 2,500), NVP 34.6wt%

PVP (Mw=10,000), NVP 34.3wt%

PVP-NVP-CO ₂ system with different molecular weight PVP-NVP-CO ₂ system with different molecular weight

Temperature(

C)

40 60 80 100 120 140 160 180 200

P re ssu re (ba r)

0 500 1000 1500 2000

PVP (Mw=29,000), NVP 29.7wt%

PVP (Mw=55,000), NVP 30.3wt%

PVP (Mw=29,000), NVP 36.6wt%

PVP (Mw=55,000), NVP 36.6wt%

PVP Mw = 2,500 PVP Mw = 29,000

PVP Mw = 29,000

PVP Mw = 55,000

ƒ We measured pressure – composition(P-x) isotherms for binary mixture of CO ₂ + NVP system at temperature from 324K to 355K and pressure up to 190bar.

ƒ We measured cloud point pressures for the system PVP +

NVP + CO ₂ system as a function of molecular weight and NVP contents at temperature up to 450K and pressure up to 2,200bar.

ƒ As the NVP content increased, cloud point pressure dramatically decreased.

ƒ But for molecular weight dependency for cloud point pressure, the result is not yet distinct at low NVP content.

Conclusion

Conclusion

Reference Reference

[1] Jennings, D. W., Lee, R. J., Teja, A. S., 1991, Vapor-liquid equilibria in the carbon dioxide + ethanol and carbon dioxide + 1-butanol

systems, J. Chem. Eng. Data, 36 : 303.

[2] Peng, D., Robinson, D. B., 1976, A new two-constant equation of state, Ind. Eng. Chem. Fundam. 15 : 59.

[3] Kuester, J. L., Mize, J. H., 1973, Optimization techniques with Fortran, McGraw-HILL Book Company.

[4] The DIPPR Database for chemistry and materials science; Design Institute for Physical Property Data, produced by AIChE, New York, 1990.

[5] Reid, R. C., Plausnitz, J. M., Poling, B. E., 1987, The properties of Gases and liquids, 4

^th