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Design of a packed column for absorption of carbon dioxide in DEA promoted hot K2CO3 solution
Design of a packed column for absorption of carbon dioxide in DEA promoted hot K&O, solution D. Phaneswara
Rao
Department of Chemical Engineering, New Delhi 1 10 016, India
Received
17 July 1989
The design procedure
developed
by Kumar and Rao lo for the design of a packed column in a natural gas
based ammonia
plant for absorption
acid is extended
to the DEA promoted
and Savage16 for the DEA promoted height of packed corresponding
Keywords:
Indian Institute of Technology, Hauz Khas,
bed required
dioxide
in hot K2C03
hot K2C03 system. absorption
of CO, in hot K,CO,
conditions
packed columns;
typical
solution
The recently
to remove CO2 up to 1000
to a set of operating
absorption;
of carbon
promoted
published
kinetics
by arsenious of Tseng,
Ho
solution was used to calculate
the
ppm. This was found to be equal to 10.5
m,
of a split flow absorber.
diethanolamine
Nomenclature a
Wetted
c
Concentration
ClJ
D F
Gs h H I
k
K, K2 k,
interfacial
area (ml rn-?)
of a species in the solvent
(kmol m-‘) Specific heat (kJ kg-’ "C' ) Diffusivity (m* s-‘) Molar flow rate of a species (kmol s-‘) Molar flow of inerts in the gas (kmol s-‘) Liquid to gas overall heat transfer coefficient Wm -20C-‘s-‘) Henry’s law constant (atm m3 kmol-‘) Enhancement factor Reaction rate constant (dm3 g-’ mol-’ s-’ for OH and (dm3)’ mole2 s-’ for Z-OH, Z-Am and Z-CO3 reactions) Equilibrium constant for the reaction CO, + CO:- + H, 0 = 2H CO; Equilibrium constant (cm’ g-’ mol-‘) for the reaction H CO; = H+ + CO:Gas film mass transfer coefficient
Introduction Kumar and Rae” developed a method for the design of a packed column for absorption of CO* in hot K,CO, solution promoted by arsenious acid. In their they took into account the variation of model, temperature along the height of the column. They also took into account the variation of all the temperature and composition dependent parameters, such as, heat and mass transfer coefficient, interfacial area, rate constant, equilibrium constant, diffusivity, and physical properties. They used the explicit equation for enhancement factor developed by Joshi et al.’ to predict 0950-42 14/90/010058-04 0 1990 Butterworth Et Co (Publishers) Ltd.
58
Gas Separation Et Purification 1990
Vol 4 March
Kg k”, L p” PP
Pi
1: Y Y
(kmol mm3 s-’ atm-‘) Overall gas phase mass transfer coefficient (kmol m-* s-’ atm-‘) Liquid phase physical mass transfer coefticient (m s-‘) Volumetric flow rate of the solvent (m’ ss’) Molarity of the solvent (kmol m-‘) Pressure of the gas in the absorber (atm) Equilibrium partial pressure of CO1 corresponding to a bulk liquid composition (atm) Equilibrium partial pressure of CO? at the interface (atm) Heat of reaction (kJ kmol-‘) Heat of absorption (kJ mol-‘) Temperature (K) Fractional saturation in the liquid phase Mole fraction of CO? in the gas
enhancement factors for absorption of CO, in carbonate solutions. In the present work, the rate equation developed by Tseng. Ho and Savage” waz incorporated into the design programme to study the column design for absorption of CO? in DEA promoted carbonate The solution. following assumptions are made in the present work: 1 2
Plug flow of gas and liquid exists in the column. The explicit equation for enhancement factor developed by Joshi et al.’ is applicable for the DEA promoted carbonate system.
Design of a packed column for absorption of Cop: D. Phaneswara
K&O3 solution is fed to the absorber at its top in lean form and also in semilean form at an intermedi’ate location. no depletion of the promoter There is concentration in the film. The rate controlling steps are the reaction of CO, with OH-, and abstraction of proton from the zwitterion intermediate by OH-, free amine, and carbonate ion. The rate constants for these steps are given as’? log&o,
where: H is the enthalpy of gas stream; h is partial molal enthalpy of a liquid stream component; subscripts i and s are the components mentioned in the reaction scheme and inerts, respectively. Molar flow rates of the liquid phase components entering or leaving the system are related by the following material balance equations:
FTI
+
-
FM,
FB,
=
FT2
+
FM2
-
F,,
=
FB3 - ‘“;1+FM3)
=A
2895 = 13.635 - T + 0.0081
k, _ oH = exp(25.63 - 2513/T)
(2)
= exp(33.98 - 7220/T)
(3)
&-A,,,
Rao
Kz - co1 = exp(27.96 - 5922/T)
the variables FBi in Equation (8), we get:
After eliminating help of Equation
G,HB,
+
(8)
V4w- HT.&~
yT ~l
_
yT
-
G,HT,
(7) with the
AQR
+
+
AQ,
(4) 3
where I is ionic strength of the solution. Corresponding to the above kinetics, the expression for k, in the pseudo-first order fast reaction regime will be given by:
+
WB~
-
HB,M
FTi(hBi
=
-
ATi)
c I=1
3
k, = &,#o,(OH-j
+ kz-o&W(OH-j
FMi(hB;
+
-
hMi)
+ kz.,&W(Am) + kz-cog(Amj(co:-j] 6
I”~
(5)
The equation for equilibrium vapour pressure of CO2 over carbonate solutions is given in Reference 2 by the equation 9.51 of Astarita et al. and the equilibrium vapour pressure is not affected by the presence of small amounts of DEA. Solubility of CO, is not affected by the presence of DEA.
7
where HB14is molal enthalpy of CO, in the gas phase at the exit liquid temperature. Mole balance equations across a differential element of the packed bed of height dz can be written as given below: =dF
2
=dF
I
z-3
(10)
2
= k,a(PY - Pi)dz
Based on the above assumptions, the design/simulation equations for a counter-flow packed column can be written as detailed below.
(11) Reaction
scheme = K,a(PY - pc)dz
COz + K2COj + Hz0 = 2KH CO3 (4)
(1)
(2)
Overall
mole balance
(3)
Component
index
where
for the column:
+ 1=&-CT2 L&j&
- L*Csz
1
YB +
GsHm
~
1-y,+
c i=l
= GsH,, + Gsff~4 [&]
+
c
pc = 1.95 X 109m0-4exp for Henry’s
FMihM, logH=0.125m+5.30-p
i=l
+ i Faihai ,=I
(13)
Based on the assumption in point 6 mentioned above, the equation for the equilibrium partial pressure of CO, can be written as follows:
The equation Equation (2)
3
Frihri
H
(6)
Overall energy balance
G,ff,,
1
Ku - K,a + IkFa
where Y stands for the mole fraction of CO, in the gas. Subscripts T, M, and B stand for the top, intermediate feed location, and bottom of the column and A stands for the total amount of CO* to be absorbed.
3
(12)
(7)
Law constant
is given
1140
as
(15)
T
Based on the assumption in point 2 given above the expression for the enhancement factor can be written as:
Gas Separation
8 Purification 1990
Vol 4 March
59
Design of a packed column for absorption of CO,: D. Phaneswara
1 + 5.2(P’ + 1)P’” Q,o.,s
I=
r
- l}[gr’
(16)
where Q’ = 1 + Z;
(17)
p’=z,-1
(18)
(1 -Y)
(19)
Y
Rao
Equation (10) determines the changes in the molar flow rates of components in the liquid phase for a given amount of CO, absorbed from the gas phase. Equation (11) is a flux balance at the gas-liquid interface, and can be used to calculate the interfacial partial pressure p,. Equation (12) defines the overall gas film coefficient. 1 is the enhancement factor determined from Equations (16)-(25). Equation (26) accounts for the changes in the volumetric flow rate ofliquid, L. Equation (27) defines the relationship between the gas and liquid temperatures, whereas Equation (29) gives the gas temperature that is determined by the value of the gas to liquid heat transfer coefficient. h. Equation (30) gives the flow rates of liquid phase components in terms of fractional saturation. y.
(21)
X = Pi/P,
Calculation K,=exp(y+6..59)
(22)
IF = kJk;
(23)
where k, is given by Equation (5) in which the concentrations of OH-, Am and CO:-, correspond to bulk conditions. The concentrations of OH- and CO:- can be calculated by using the following equations: [OH-]
=
$” !$? 2
[co:-] = m(1
- y)
The equations Differential
for K, and K, are given by Tseng et al.“. mass balance:
(25)
dY = uGs(*~ _ y)2
Differential
=
d(Lp) = pdL
(26)
energy balance
(QR + Qs + C,,Vg - TLWS d
+
= F’C,,
dT,
(27)
where F’
=
c
&M
(28)
i=l
Heat transfer
model: dT, = ha(T, - T,)dz
Wps + W, Defining F3
=
equations
for conversion.
Y, of carbonate:
~F,,Y
Fz = L,m(l
-y)
= F2,,y
F, = F,, - Frov
60
(29)
Gas Separation
(30)
& Purification
1990
Vol 4 March
of height
of tower
The calculation of the height of the tower is done by integrating the differential Equations (lo), (27) and (29) along with the other equations by starting the calculations from the bottom conditions of the tower. By assuming that the gas temperature is equal to the solvent temperature at the top of the tower, which is nearly true. the temperature of the rich solution at the tower bottom can be calculated from the overall energy balance equation for the tower. The value of the solute concentration at the gas-liquid interface at any axial position in the tower can be calculated by using the successive substitution method. Standard sources of physical property data literature’.4.5,8.‘3.‘4 were used to obtain the equations for specific gravity, specific heat, viscosity, thermal conductivity, diffusivity and surface tension. For wetted surface area of packings and gas side mass transfer coefficient, correlations of Onda et al.” were used. To estimate a, the correlation of Mohunta et al.” was found to give more realistic answers to the height of the column than the Onda’s correlation recommended by Astarita et al.‘. To estimate the gas side heat transfer coefficient correlation 18.63 in Perry’s sixth edition of Chemical Engineering Handbook was used”. Typical computer results for a set of column operating conditions are given below: gas flow rate: 3082 k mol h-’ CO, in the gas at the top of the absorber: 0.1% gas temperature at the bottom of the absorber: 107°C pressure of gas in the absorber: 375 psia total equivalent concentration of K&O, in the feed solvent: 25% (by weight) liquid temperature at the top of the absorber: 70°C concentration of DEA: 0.25 mol dm-’ volumetric flow rate of semilean solution: 149 m3 h-’ volumetric flow rate of lean solution: 514 m3 h-’ temperature of semilean solution: 119.8”C fractional saturation of semilean solution: 0.5 fractional saturation of lean solution: 0.25 feed gas composition: H,: 54.8%; N,: 17.7%; CO,: 2 I .6%: CO: 0.3%; CH,: 0.4%; Ar: 0.2%: H,O: 5.0%; type of packing: 37 mm ceramic Intalox saddles height of tower: 10.5 m Recently Sanyal et al.” modelled absorption of CO, in DEA promoted carbonate solutions by assuming the reaction to be instantaneous. The present work eliminates the need to make such an assumption.
Design of a packed cofumn for absorption of CO,: D. Pitaneswara
Conclusion
5
The design equations employed in the present work appear to give tower heights in the range that can be expected for DEA promoted carbonate processes.
6
8
Acknowledgements The author wishes to acknowledge gratefully the Computer Service Centre of IIT, Delhi, for granting the necessary computing time.
9 10 II 12 13
References Astarita, G. Mass Transfer with Chemical Reaction Elsevier, Amsterdam. The Netherlands (1967) Astarita, G., Savage, D.W. and Bisio, A. Gas Treating with ChemicalSolvents John Wiley and Sons. Chichester, UK(1983) Astarita, G. and Savage, D.W. Chem Eng Sci (1980) 35 649 Danckwerts, P.V. Gas Liquid Reactions McGraw Hill, New York. USA (1970)
14
15 16 17
Rao
Danckwerts, P.V. and Sharma, M.M. Chem Eng (October 1966) CE 244 Haimour, N., Bidarian, A. and Sandatt, O.C. Chem Eng Sci (1987) 42 1393 Joshi, S.V., Astarita, G. and Savage, D.W. AIChE Symp. Ser. No. 202 (1981) 77 63 Kohl, A. and Riesenfeld, F. Gas Purification 4th Edn, Gulf Publishing Co.. USA (1985) Kim, CJ. and Savage, D.W. Chem Enn Sci (1987) 42 1481 Kumar, N. and Rat D.P. Gas Sep &$(1989) 3.152 Mohunta. D.M.. Vaidvanathan. AS. and Laddha. G.S. Indian Chem Eng ‘(1969) i 1 39 Onda, K., Takeuchi, M. and Okumoto, Y. J Chem Eng Jpn (1968) 1 56 Perry, R.H. and Green, D. Chemical Engineers Handbook 6th Edn, McGraw Hill. New York, USA (1984) Reid, R.C., Prausnitz, J.M. and Sherwood, T.K.Propertiesof Gases and Liquids - Their Estimation and Correlation 3rd Edn, McGraw Hill, New York, USA (1977) Sanyal, D., Vasishtha, N. and Saraf, D.N. Ind Eng Chem Res (1988) 27 2149 Tseng, P.C., Ho, W.S. and Savage, D.W. AIChE J (1988) 34 922 Versteeg, G.F. and Van Swaaij, W.P.M. Chem Eng Sci (1988) 43 573
Gas Separation
8 Purification
1990
Vol 4 March
61
Rao
Department of Chemical Engineering, New Delhi 1 10 016, India
Received
17 July 1989
The design procedure
developed
by Kumar and Rao lo for the design of a packed column in a natural gas
based ammonia
plant for absorption
acid is extended
to the DEA promoted
and Savage16 for the DEA promoted height of packed corresponding
Keywords:
Indian Institute of Technology, Hauz Khas,
bed required
dioxide
in hot K2C03
hot K2C03 system. absorption
of CO, in hot K,CO,
conditions
packed columns;
typical
solution
The recently
to remove CO2 up to 1000
to a set of operating
absorption;
of carbon
promoted
published
kinetics
by arsenious of Tseng,
Ho
solution was used to calculate
the
ppm. This was found to be equal to 10.5
m,
of a split flow absorber.
diethanolamine
Nomenclature a
Wetted
c
Concentration
ClJ
D F
Gs h H I
k
K, K2 k,
interfacial
area (ml rn-?)
of a species in the solvent
(kmol m-‘) Specific heat (kJ kg-’ "C' ) Diffusivity (m* s-‘) Molar flow rate of a species (kmol s-‘) Molar flow of inerts in the gas (kmol s-‘) Liquid to gas overall heat transfer coefficient Wm -20C-‘s-‘) Henry’s law constant (atm m3 kmol-‘) Enhancement factor Reaction rate constant (dm3 g-’ mol-’ s-’ for OH and (dm3)’ mole2 s-’ for Z-OH, Z-Am and Z-CO3 reactions) Equilibrium constant for the reaction CO, + CO:- + H, 0 = 2H CO; Equilibrium constant (cm’ g-’ mol-‘) for the reaction H CO; = H+ + CO:Gas film mass transfer coefficient
Introduction Kumar and Rae” developed a method for the design of a packed column for absorption of CO* in hot K,CO, solution promoted by arsenious acid. In their they took into account the variation of model, temperature along the height of the column. They also took into account the variation of all the temperature and composition dependent parameters, such as, heat and mass transfer coefficient, interfacial area, rate constant, equilibrium constant, diffusivity, and physical properties. They used the explicit equation for enhancement factor developed by Joshi et al.’ to predict 0950-42 14/90/010058-04 0 1990 Butterworth Et Co (Publishers) Ltd.
58
Gas Separation Et Purification 1990
Vol 4 March
Kg k”, L p” PP
Pi
1: Y Y
(kmol mm3 s-’ atm-‘) Overall gas phase mass transfer coefficient (kmol m-* s-’ atm-‘) Liquid phase physical mass transfer coefticient (m s-‘) Volumetric flow rate of the solvent (m’ ss’) Molarity of the solvent (kmol m-‘) Pressure of the gas in the absorber (atm) Equilibrium partial pressure of CO1 corresponding to a bulk liquid composition (atm) Equilibrium partial pressure of CO? at the interface (atm) Heat of reaction (kJ kmol-‘) Heat of absorption (kJ mol-‘) Temperature (K) Fractional saturation in the liquid phase Mole fraction of CO? in the gas
enhancement factors for absorption of CO, in carbonate solutions. In the present work, the rate equation developed by Tseng. Ho and Savage” waz incorporated into the design programme to study the column design for absorption of CO? in DEA promoted carbonate The solution. following assumptions are made in the present work: 1 2
Plug flow of gas and liquid exists in the column. The explicit equation for enhancement factor developed by Joshi et al.’ is applicable for the DEA promoted carbonate system.
Design of a packed column for absorption of Cop: D. Phaneswara
K&O3 solution is fed to the absorber at its top in lean form and also in semilean form at an intermedi’ate location. no depletion of the promoter There is concentration in the film. The rate controlling steps are the reaction of CO, with OH-, and abstraction of proton from the zwitterion intermediate by OH-, free amine, and carbonate ion. The rate constants for these steps are given as’? log&o,
where: H is the enthalpy of gas stream; h is partial molal enthalpy of a liquid stream component; subscripts i and s are the components mentioned in the reaction scheme and inerts, respectively. Molar flow rates of the liquid phase components entering or leaving the system are related by the following material balance equations:
FTI
+
-
FM,
FB,
=
FT2
+
FM2
-
F,,
=
FB3 - ‘“;1+FM3)
=A
2895 = 13.635 - T + 0.0081
k, _ oH = exp(25.63 - 2513/T)
(2)
= exp(33.98 - 7220/T)
(3)
&-A,,,
Rao
Kz - co1 = exp(27.96 - 5922/T)
the variables FBi in Equation (8), we get:
After eliminating help of Equation
G,HB,
+
(8)
V4w- HT.&~
yT ~l
_
yT
-
G,HT,
(7) with the
AQR
+
+
AQ,
(4) 3
where I is ionic strength of the solution. Corresponding to the above kinetics, the expression for k, in the pseudo-first order fast reaction regime will be given by:
+
WB~
-
HB,M
FTi(hBi
=
-
ATi)
c I=1
3
k, = &,#o,(OH-j
+ kz-o&W(OH-j
FMi(hB;
+
-
hMi)
+ kz.,&W(Am) + kz-cog(Amj(co:-j] 6
I”~
(5)
The equation for equilibrium vapour pressure of CO2 over carbonate solutions is given in Reference 2 by the equation 9.51 of Astarita et al. and the equilibrium vapour pressure is not affected by the presence of small amounts of DEA. Solubility of CO, is not affected by the presence of DEA.
7
where HB14is molal enthalpy of CO, in the gas phase at the exit liquid temperature. Mole balance equations across a differential element of the packed bed of height dz can be written as given below: =dF
2
=dF
I
z-3
(10)
2
= k,a(PY - Pi)dz
Based on the above assumptions, the design/simulation equations for a counter-flow packed column can be written as detailed below.
(11) Reaction
scheme = K,a(PY - pc)dz
COz + K2COj + Hz0 = 2KH CO3 (4)
(1)
(2)
Overall
mole balance
(3)
Component
index
where
for the column:
+ 1=&-CT2 L&j&
- L*Csz
1
YB +
GsHm
~
1-y,+
c i=l
= GsH,, + Gsff~4 [&]
+
c
pc = 1.95 X 109m0-4exp for Henry’s
FMihM, logH=0.125m+5.30-p
i=l
+ i Faihai ,=I
(13)
Based on the assumption in point 6 mentioned above, the equation for the equilibrium partial pressure of CO, can be written as follows:
The equation Equation (2)
3
Frihri
H
(6)
Overall energy balance
G,ff,,
1
Ku - K,a + IkFa
where Y stands for the mole fraction of CO, in the gas. Subscripts T, M, and B stand for the top, intermediate feed location, and bottom of the column and A stands for the total amount of CO* to be absorbed.
3
(12)
(7)
Law constant
is given
1140
as
(15)
T
Based on the assumption in point 2 given above the expression for the enhancement factor can be written as:
Gas Separation
8 Purification 1990
Vol 4 March
59
Design of a packed column for absorption of CO,: D. Phaneswara
1 + 5.2(P’ + 1)P’” Q,o.,s
I=
r
- l}[gr’
(16)
where Q’ = 1 + Z;
(17)
p’=z,-1
(18)
(1 -Y)
(19)
Y
Rao
Equation (10) determines the changes in the molar flow rates of components in the liquid phase for a given amount of CO, absorbed from the gas phase. Equation (11) is a flux balance at the gas-liquid interface, and can be used to calculate the interfacial partial pressure p,. Equation (12) defines the overall gas film coefficient. 1 is the enhancement factor determined from Equations (16)-(25). Equation (26) accounts for the changes in the volumetric flow rate ofliquid, L. Equation (27) defines the relationship between the gas and liquid temperatures, whereas Equation (29) gives the gas temperature that is determined by the value of the gas to liquid heat transfer coefficient. h. Equation (30) gives the flow rates of liquid phase components in terms of fractional saturation. y.
(21)
X = Pi/P,
Calculation K,=exp(y+6..59)
(22)
IF = kJk;
(23)
where k, is given by Equation (5) in which the concentrations of OH-, Am and CO:-, correspond to bulk conditions. The concentrations of OH- and CO:- can be calculated by using the following equations: [OH-]
=
$” !$? 2
[co:-] = m(1
- y)
The equations Differential
for K, and K, are given by Tseng et al.“. mass balance:
(25)
dY = uGs(*~ _ y)2
Differential
=
d(Lp) = pdL
(26)
energy balance
(QR + Qs + C,,Vg - TLWS d
+
= F’C,,
dT,
(27)
where F’
=
c
&M
(28)
i=l
Heat transfer
model: dT, = ha(T, - T,)dz
Wps + W, Defining F3
=
equations
for conversion.
Y, of carbonate:
~F,,Y
Fz = L,m(l
-y)
= F2,,y
F, = F,, - Frov
60
(29)
Gas Separation
(30)
& Purification
1990
Vol 4 March
of height
of tower
The calculation of the height of the tower is done by integrating the differential Equations (lo), (27) and (29) along with the other equations by starting the calculations from the bottom conditions of the tower. By assuming that the gas temperature is equal to the solvent temperature at the top of the tower, which is nearly true. the temperature of the rich solution at the tower bottom can be calculated from the overall energy balance equation for the tower. The value of the solute concentration at the gas-liquid interface at any axial position in the tower can be calculated by using the successive substitution method. Standard sources of physical property data literature’.4.5,8.‘3.‘4 were used to obtain the equations for specific gravity, specific heat, viscosity, thermal conductivity, diffusivity and surface tension. For wetted surface area of packings and gas side mass transfer coefficient, correlations of Onda et al.” were used. To estimate a, the correlation of Mohunta et al.” was found to give more realistic answers to the height of the column than the Onda’s correlation recommended by Astarita et al.‘. To estimate the gas side heat transfer coefficient correlation 18.63 in Perry’s sixth edition of Chemical Engineering Handbook was used”. Typical computer results for a set of column operating conditions are given below: gas flow rate: 3082 k mol h-’ CO, in the gas at the top of the absorber: 0.1% gas temperature at the bottom of the absorber: 107°C pressure of gas in the absorber: 375 psia total equivalent concentration of K&O, in the feed solvent: 25% (by weight) liquid temperature at the top of the absorber: 70°C concentration of DEA: 0.25 mol dm-’ volumetric flow rate of semilean solution: 149 m3 h-’ volumetric flow rate of lean solution: 514 m3 h-’ temperature of semilean solution: 119.8”C fractional saturation of semilean solution: 0.5 fractional saturation of lean solution: 0.25 feed gas composition: H,: 54.8%; N,: 17.7%; CO,: 2 I .6%: CO: 0.3%; CH,: 0.4%; Ar: 0.2%: H,O: 5.0%; type of packing: 37 mm ceramic Intalox saddles height of tower: 10.5 m Recently Sanyal et al.” modelled absorption of CO, in DEA promoted carbonate solutions by assuming the reaction to be instantaneous. The present work eliminates the need to make such an assumption.
Design of a packed cofumn for absorption of CO,: D. Pitaneswara
Conclusion
5
The design equations employed in the present work appear to give tower heights in the range that can be expected for DEA promoted carbonate processes.
6
8
Acknowledgements The author wishes to acknowledge gratefully the Computer Service Centre of IIT, Delhi, for granting the necessary computing time.
9 10 II 12 13
References Astarita, G. Mass Transfer with Chemical Reaction Elsevier, Amsterdam. The Netherlands (1967) Astarita, G., Savage, D.W. and Bisio, A. Gas Treating with ChemicalSolvents John Wiley and Sons. Chichester, UK(1983) Astarita, G. and Savage, D.W. Chem Eng Sci (1980) 35 649 Danckwerts, P.V. Gas Liquid Reactions McGraw Hill, New York. USA (1970)
14
15 16 17
Rao
Danckwerts, P.V. and Sharma, M.M. Chem Eng (October 1966) CE 244 Haimour, N., Bidarian, A. and Sandatt, O.C. Chem Eng Sci (1987) 42 1393 Joshi, S.V., Astarita, G. and Savage, D.W. AIChE Symp. Ser. No. 202 (1981) 77 63 Kohl, A. and Riesenfeld, F. Gas Purification 4th Edn, Gulf Publishing Co.. USA (1985) Kim, CJ. and Savage, D.W. Chem Enn Sci (1987) 42 1481 Kumar, N. and Rat D.P. Gas Sep &$(1989) 3.152 Mohunta. D.M.. Vaidvanathan. AS. and Laddha. G.S. Indian Chem Eng ‘(1969) i 1 39 Onda, K., Takeuchi, M. and Okumoto, Y. J Chem Eng Jpn (1968) 1 56 Perry, R.H. and Green, D. Chemical Engineers Handbook 6th Edn, McGraw Hill. New York, USA (1984) Reid, R.C., Prausnitz, J.M. and Sherwood, T.K.Propertiesof Gases and Liquids - Their Estimation and Correlation 3rd Edn, McGraw Hill, New York, USA (1977) Sanyal, D., Vasishtha, N. and Saraf, D.N. Ind Eng Chem Res (1988) 27 2149 Tseng, P.C., Ho, W.S. and Savage, D.W. AIChE J (1988) 34 922 Versteeg, G.F. and Van Swaaij, W.P.M. Chem Eng Sci (1988) 43 573
Gas Separation
8 Purification
1990
Vol 4 March
61