Prediction Reactive Residue Curve Map (rRCM) for ... m 2 x.pdfReactions can lead to the...

Prediction of Reactive Residue Curve Map

(RCM) for Quaternary System

Dr. Zaidoon M. Shakoor

Chemical Engineering Department/University of Technology/ Baghdad E-mail: [email protected]

ABSTRACT In this study, residue curve map for quaternary reactive system was predicted. Single

residue curve behaves as batch distillation with single equilibrium stage. The reactive residue

curve map constructed based upon vapor-liquid equilibrium and reaction kinetics. Butyl

acetate and water production from n-butanol and acetic acid was taken as case study.

UNIQUAC model was used to determine the liquid phase activity coefficients while the vapor

phase assumed ideal. The mathematical representation involve many algebraic equations AE

and four complex differential algebraic equations DAEs which solved by using ode15s

command built-in MATLAB program. It was obtained that, the catalyst weight is the main

effective variable on the shape of reactive residue curve map. Also the results from developed

program compared with the published in the literature for the same reaction, showing the

efficiency of the developed program to obtain the residue curve map for any non-ideal system

reactive or non-reactive with any number of components. KEYWORDS: Residue curve map, Reactive, MATLAB, Butyl acetate.

INTRODUCTION Residue curve map (RCM) is a collection of the liquid residue curves in a simple one-stage

batch distillation originating from different initial compositions. The residue curve mapping

technique (RCM) was considered as powerful tool for the flow-sheet development and

preliminary design of conventional multi-component separation processes P

(1)P.

Design of reactive distillation column requires kinetic data in addition to phase equilibria.

The feasibility of reactive distillation column based on residue curve maps (RCM) for non-

reactive stages and on reactive residue curve maps (RRCM) for reactive stages.

n-Butyl acetate is important solvent in the chemical industry. It used in coating and

painting processes, lacquer industry and cosmetic formulations (2, 3, 4). Gangadwala et al. (5)

Figure (1) illustrates the set-up for prediction the residue curve map experimentally. To

construct the RCM experimentally, a liquid mixture is charged to the still pot and the pot is

differentially heated to produce vapor. The vapor in equilibrium with the liquid is removed as

soon as it forms. Because the vapor is always richer in the more volatile components than the

liquid, the liquid composition changes continuously with time, becoming more and more

concentrated in the least volatile species. The composition of liquid in still pot versus time

produces single residue curve map. By starting from different initial compositions, different

residue curves were formed and the plot of these curves is called residue curve map.

By using appropriate thermodynamic model, it is easy to construct the residue curves

theoretically without making any experiments. The residue curve maps are usually generated

theoretically using commercial software’s such as Aspen Plus, DISTIL and ChemSep. All

these software’s is useful only to predict residue curve map for ternary non-reactive systems,

for example ChemSep create residue curve maps for a simple ternary system with constant

relative volatilities.

Due to importance of RCMs and RRCMs to understand the behavior of both conventional

and reactive distillation columns, therefore the main aim of this study is to develop a

computer program to predict reactive or non reactive residue curve maps for quaternary

system and study the effect of catalyst weight on the shape of reactive residue curve map

theoretically.

REACTIVE RESIDUE CURVE MAP Residue curve maps have been extensively studied since 1900. Most of the literatures over

110 years for residue curve maps and distillation boundaries is restricted to three-component

mixtures. The simple RCM was modeled by the set of differential equations P

(6)P.

(1) ii

i yxddx

−=ξ

Where ξ is a dimensionless time, x

explored various process configurations for the production of n-butyl acetate to achieve a high

purity of the desired product using reactive distillation process.

i is the mole fraction of species i in the liquid phase, and

yi is the mole fraction of species i in the vapor phase. The yi values are related with the xi

values using equilibrium constants Ki

Considerable attention has been paid over the last 25 years on construction RRCM. Kinetic

controlled RCM may be quite different from nonreactive RCM. Chemical reactions can

influence residue curve maps in some important ways. Reactions can lead to the

disappearance of some azeotropes that exist in the absence of reaction also chemical reactions

can also lead to the creation new azeotropes that would not exist in the absence of reaction.

.

Barbosa and Doherty (7)

The influence of reaction kinetics on chemical phase equilibrium and reactive azeotrope

was investigated first by Venimadhavan et al.

developed the RCMs for reactive distillation processes with single

chemical equilibrium reaction.

(8)

+−=

ξ ∑∑∑= ==

N

1i

M

1jjj,iij

m

1jji,

refii

i )rv(x-)r(vkDa)yx(

ddx

. They introduced the dimensionless group

named Damköhler number to characterize the ratio of reaction rate and escaping flow rate so

that it became possible to study the kinetic controlled RCMs in addition to nonreactive and

reactive cases. For a single reaction, the equations used to compute the reactive residue curves

are:

(2)

Where Da is the Damkohler number, defined by:

refocat k

VVDa ρ

= (3)

Where Vo

Fien and Liu P

(9)P used residue curve maps as shortcut design for separation processes. They

concluded that, RCM technique is suitable only for vapor-liquid equilibrium-based processes.

Ung and Doherty P

(10)P extended the method of Barbosa and Doherty to systems with multiple

equilibrium chemical reactions. Thiel et al. P

(11)P studied the RCMs for synthesis of the fuel

ethers MTBE and TAME by reactive distillation using heterogeneous catalysts. Song et al. P

(12)P

performed the measurement of RCM and heterogeneous kinetics for methyl acetate synthesis.

Venimadhavan et al. P

(13)P used the Damköhler number, to study the kinetic controlled RCMs in

addition to nonreactive and equilibrium reactive cases. Doherty and Malone P

(14)P discussed

RCM for different mixtures including esters. Rivera and Grievink P

(1)P applied RCM feasibility

analysis to the homogeneous reactive distillation synthesis of methyl tert -butyl ether (MTBE)

at 11 atm. They concluded that, the RCM technique is limited by its intrinsic graphical nature

and requires accurate thermodynamic data in order to correctly describe reactive distillation

processes. Bellows and Lucia

is the initial molar flow of vapor leaving the still.

(15) used residue curve map to determine distillation boundaries

for four- component non-reactive mixtures that exhibit azeotrop. Bonet-ruiz et al. (16)

in their

study used MATLAB program to provide a set of residue curve maps for TAME at various

values of pressure and Da number governing the industrial operating conditions.

NUMERICAL COMPUTATION The non-reactive residue curve map computed for the system by integrating equation (1)

forward with dimensionless time ξ from different starting positions mean evaporating light

components and end at the maximum boiling temperature azeotrope, also integrating equation

(1) backward in dimensionless time ξ from the same starting positions mean evaporating

heavy components and end at the minimum boiling temperature azeotrope. The driving force

(xRiR - yRiR) is the difference of the liquid phase xRiR and vapor phase yRiR compositions. At the

azeotrope, the driving force is equal to zero, because at azeotrope (xRiR = yRiR).

The reactive residue curve map was computed using the same mathematical procedure

described above for non-reactive system. Equation (2) integrated using fourth order Runge-Kutta integration method. The integration is continuous until a singular point is reached. The

singular points occur when the composition of a pure component is reached or

when ii yx = or 0d/dx =ξ which corresponds to reactive azeotrope.

These curves are computed and plotted using MATLAB program with the aid of built-in

command named ode15s, which used to integrate of the DAEs numerically with the aid of

fourth order Runge-Kutta method. To compute the vapor-liquid equilibrium and since there is

deviation from ideality in the liquid phase, an appropriate expressions of the activity

coefficients was used. Figure (2) represent the flowchart of reactive residue curve map

prediction program.

PLOTTING RESIDUE CURVE MAP The ternary RCM usually represented using ternary diagram consists of a triangular

(preferably equilateral) plot with each vertex representing a pure component. For the systems

consists more than three components such as quaternary system, the graphical representation

of the RCMs becomes more difficult. A simple plot of residue curve maps in a planar

triangular diagram is only useful for a three component mixture. To represent quaternary

systems, it is always possible to plot the data in three-dimensional 3D form (a triangular

pyramid made of equilateral triangles). Unfortunately, reading data in 3D is hard. Several

hypotheses exist, from lumping similar compounds together to following topographical

strategies of representing 2D planar cuts and projections of the pyramid or removing one of

the components and recalculating molar fractions, collapsing the 3D RCM to one of its sides

P

(11)P.

VAPOR LIQUID EQUILIBRIUM

For non-ideal mixture or azeotropic mixture additional variable iγ (liquid phase activity

coefficient) appears in vapor-liquid equilibrium equation. To describe the phase equilibrium

of a system of NRCR components at a temperature T and pressure PRtR the following equation was

used.

x

PPy i

t

satii

i ⋅γ

=

(4)

Where represents degree of deviation from reality.

The UNIQUAC model P

(17)P was used to determine the activity coefficients in the liquid

phase while the vapor phase was assumed to be ideal. This model distinguishes two

contributions termed combinatorial Co and residual Rs. Rsi

Coii lnlnln γ+γ=γ (5)

Where,

∑=

φ−+

φθ

+φ

=γC

1jjj

i

ii

i

ii

i

iCoi lx

xllnq

2z

xlnln

(6)

∑∑

∑=

=

= τθ

τθ−+

τθ−=γ

C

1jC

1kkjk

ijjii

C

1jjiii

Rsi qqlnqln (7)

Where,

−−=τ

RTuu

exp iijiij

(8)

∑=

=φ C

1jjj

iii

xr

xr (9)

∑=

=θ C

1jjj

iii

xq

xq (10)

iγ

)1r()qr)(2z(l jjij −−−= (11)

Where 10=z

The values of the various parameters for the UNIQUAC model equation can be found in

tables (1) and (2).

REACTION KINETICS The esterification of the acetic acid (HAc) with n-butanol (n-BuOH) to produce n-butyl

acetate (n-BuAc) and water (H2O) was taken into consideration. This reversible reaction is

represented by the equation:

(W) BuAc)-(n BuOH)-(n (HAc) H2OCH3COOC4H9C4H9OHCH3COOH H +→←+ +

The heterogeneous reaction kinetics of n-butanol esterification with acetic acid has been

studied by many authors (Liao and Tong (18); Liao and Zhange (19); Janowsky et al. (20); Zheng

and Zeng (21, 22) and Steinigeweg and Gmehling (23)

Reaction kinetics of the n-BuAc synthesis is usually described by second order pseudo-

homogeneous models (Steinigeweg and Gmehling

).

(23) ; Gangadwala et al. (24)

Gangadwala et al. P

(24)P studied the reaction kinetics in the presence of several strongly acidic

ion exchange resins and proposed a modified Langmuir–Hinshelwood–Hougen–Watson

model in order to account for adsorption of different species on the catalytic sites. The

reaction kinetic model has the following form:

)aaKa1aa(KM

dtdx

mr OHBuAcBuOHHAcfcatjj

j 2−δ== (12)

Where,

iii xa γ=

MRcatR is the catalyst mass, aRi Ris the activity of the i P

thP component in the bulk liquid phase, xRiR

is mole fraction of the i P

thP component, and γRiR is the activity coefficient of the i P

thP component. KRfR

and Ka are the forward reaction rate constant and equilibrium constant, respectively.

The temperature dependency of the rate constants KRjR was expressed by the Arrhenius

equation:

/RT)exp(-EK K jojj = (13)

The kinetic parameters of reaction rate equation are taken from Gangadwala et al.

).

(24)

and

reported in Table (3). The values of Antoine constants, molecular weights and boiling points

are reported in Table (4).

RESULTS In Figures (3 to 16) the nonreactive and reactive the RCMs were plotted in three-

dimensional plot for butyl acetate system. In these figures the vertices represent the pure

components and any point inside this tetrahedron stands for a composition of a quaternary

mixture.

Figures (3, 4, 5 and 6) show the nonreactive residue curve map for butyl acetate system at

different pressures (1, 2, 3 and 5 atm respectively). From figure (3) it’s clear that, there are

three nodes first is stable node at 100% Butyl acetate, the second is stable node (maximum-

boiling binary azeotrope) at 58.92 % acetic acid 41.08 % n-butanol, and the third is unstable

node (minimum-boiling binary azeotrope) at 26.52 % Butyl acetate 73.48 % water. The stable

node at 100% Butyl acetate appear in all figures due to that, the butyl acetate is the highest

boiling point (126°C) and the acid is the second highest boiling point (118.1°C), followed

closely by n-butanol (117.7°C). Table (5) contains all singular points for non-reactive residue

curve map of the system at 1 atm. The obtained results are in agreement with the result

reported in the references (Löning et al. P

(26)P, Tang et al. P

(27)P).

From Figures (4, 5 and 6) it’s clear that increasing the pressure from 2 to 5 atm lead to

disappear the binary stable azeotrope that appear in 1 atm while new stable node appear at

these pressures at 100% acetic acid.

Figures (7, 8, 9, 10 and 11) shows the reactive residue curve map for butyl acetate system

at 1 atm and variable Damköhler number (0.01, 0.02, 0.03 0.04 and 0.05) respectively. All

these five figures contain four stable nodes at 100 % of each component in the quaternary

system and one unstable node (minimum-boiling) at (0.32 % Acetic acid, 0.45 n-Butanol,

26.05 % butyl acetate, 73.17 % water). All these figures have the same profile but figure (7)

differ from the others by appearing un-stable quaternary azeotrope around (66.78 % Acetic

acid, 29.55 n-Butanol, 3.31 % butyl acetate 0.36 % water). It was observed that increasing

the catalyst weight have a considerable effect on the change of the shape of the reactive

residue curve map. Also, the instability of these curves is result of interaction between the

thermodynamic equilibrium and reaction.

Figures (12, 13, 14, 15 and 16) shows the reactive residue curve map for butyl acetate

system at 1 atm pressure and Damköhler number (0.1, 0.2, 0.3 0.4 and 0.5). All these five

figures contain four stable nodes at 100 % of each component and one unstable node at (2.96

% Acetic acid, 4.30 % n-Butanol, 22.03 % butyl acetate, 70.71 % water). It’s clear from

figures (3, 4, 5 and 6) and figures (12, 13, 14, 15 and 16) that further increasing Damköhler

number does not have any significant effect on the RRCM of this quaternary system.

The obtained results are in agreement with the result reported in the references (Löning et

al. P

(26)P, Tang et al. P

(27)P).

CONCLUSION In this research, MATLAB program was developed to predict stable or un-stable

azeotropes for quaternary mixtures and then to predict both reactive and non-reactive residue

curve maps. The following conclusions are concluded.

• It can be observed from all of these figures that at low Damköhler number (Da<0.01) the

reactive residue curve is not too different than non-reactive residue curve. All the residue

curves start at unstable node moving toward the saddle point and end at the stable nodes.

• The shape of the reactive residue curves depends mainly on two essential parameters,

which are the operating pressure and the Damköhler number (Da) in the other word

catalyst weight.

• Residue curve map is a primary tool to design non-ideal distillation columns such as

azeotropic, extractive, reactive and vacuum distillation columns.

NOMENCLATURE A,B,C: Antoine’s coefficient [-] a : Activity [-] Da : Damkohler number [-] E : Activation Energy [j/mol] H : Molar holdup [mol/hr] K : Thermodynamic equilibrium constant [-] KRaR : Equilibrium constant [mol/s] KRfR : Forward reaction rate constant [mol/mol(cat)s] KRfRP

o P: forward reaction rate constant at reference temperature [mol/mol(cat)s]

MRcatR : Catalyst mass [gm] m : Molar holdup [mol] NRCR : Number of components of a mixture [-] qRiR : Molecular shape Pt : Total pressure [pa] PRiRP

satP : Saturation pressure of component i [pa]

r : Reaction rate [mol/s] ri molecular size R : Universal gas constant [J/mol.K] T : Temperature [K] t : Time [s] x :Liquid phase mole fraction [-] y :Vapor phase mole fraction [-] GREEK LETTERS Φ : Rate factor [-] φ : Fugacity coefficient [-] γ : Activity coefficient [-] ij ξ : Dimensionless time [-]

: Interaction parameter in the UNIQUAC equation, dimensionless

υ : Stoechiometric coefficient of component [-] SUBSCRIPTS i : Component number j : Reaction number LIST OF ABBREVIATIONS AE: Algebraic equation BuAc: n-butyl acetate BuOH: Butanol DAE : Differential-algebraic equations ETBE: Ethyl tertiary butyl ether HAc : Acetic acid MATLAB: Matrix Laboratory MTBE: Methyl tertiary butyl ether RCM: Residue curve map RRCM: Reactive residue curve map TAME: Tertiary amyl methyl ether VLE: Vapor Liquid Equilibrium REFERENCES 1. Rivera, C. A. and Grievink, j., (2004), ”Feasibility of Equilibrium-Controlled Reactive Distillation Process: Application of Residue Curve Mapping”, Computers and Chemical Engineering, 28, 17-25.

2. Kun Liu, A., Zhangfa, T. B, Li, L. and Xianshe, F. A, (2005), ” Separation of Organic Compounds from Water by Pervaporation in the Production of n-Butyl Acetate via Esterification by Reactive Distillation”, Journal of Membrane Science, 256, 193–201.

3. Blagova, S., Paradaa, S., Bailerb, O., Moritzb, P., Lamc, D., Weinandd R. and Hassea, H. , (2006), “Influence of Ion-Exchange Resin Catalysts on Side Reactions of the Esterification of n-Butanol with Acetic Acid”, Chem. Eng. Sci., 61, 753.

4. Steingeweg, S. and Gmehling J., (2002),‘‘n-Butyl Acetate Synthesis via Reactive Distillation: Thermodynamic Aspects, Reaction Kinetics, Pilot-Plant Experiments, and Simulation Studies,’’ Ind. Eng. Chem. Res., 41, 5483.

5. Gangadwala, J., Kienle, A., Stein, E., and Mahajani, S., (2004), “Production of Butyl Acetate by Catalytic Distillation: Process Design Studies”, Ind. Eng. Chem. Res., 43, 136.

6. Doherty, M. F., and Perkins, J. D., (1978), “On the Dynamics of f Distillation Processes. I. The Simple Distillation of Multicomponent Non-reacting, Homogeneous Liquid mixture”, Chem. Eng. Science, 33, 569-578.

7. Barbosa, D., and Doherty, M. F., (1988), “The Simple Distillation of Homogeneous Reactive Mixtures”, Chemical Engineering Science, 43, 541.

8. Venimadhavan, G., Buzad, G., Doherty, M. F., and Malone, M. F., (1994), “Effect of Kinetics on Residue Curve Maps for Reactive Distillation”, AIChE, 40(11), 1814-1824.

9. Fien, G., and Liu, Y., (1994), “Heuristic Synthesis and Shortcut Design of Separation Processes Using Residue Curve Maps: a Review”. Industrial and Engineering Chemistry Research, 33, 2505-2522.

10. Ung, S., and Doherty, M. F., (1995), “Calculation of Residue Curve Maps for mixture with multiple equilibrium chemical reactions”, Industrial Engineering and Chemical Research, 34, 3195.

11. Thiel, C., Sundmacher, K., and Hoffmann, U., (1997), “Residue Curve Maps for Heterogeneously Catalysed Reactive Distillation of Fuel Ethers MTBE and TAME” Chemical Engineering Science, 52, 993.

12. Song, W., Venimadhavan, G., Manning, J. M., Malone, M. F., and Doherty, M. F., (1998) ,”Measurement of Residue Curve Maps Heterogeneous Kinetics in Methyl Acetate Synthesis”, Industrial and Engineering Chemistry Research, 37, 1917-1928.

13. Venimadhavan, G., Malone, M. F., and Doherty, M. F., (1999), “A Novel Distillate Policy for Batch Reactive Distillation with Application to the Production of Butyl Acetate,” Ind. Eng. Chem. Res., 38, 714.

14. Doherty, M. F., Malone, M. F., (2001), “Conceptual Design of Distillation Systems”, McGraw-Hill, New York.

15. Bellows, M., and Lucia A., (2007), ”The Geometry of Separation Boundaries: Four-Component Mixtures”, American Institute of Chemical Engineers, 53(7), 1770.

16. Bonet-Ruiz, A. E., Bonet-Ruiz, J. and Plesu, V., Bozga, G. LLacuna, J. L. and Lopez, J. C., (2009), “New Contributions to Modelling and Simulation of TAME Synthesis by Catalytic Distillation”, Chemical Engineering Transactions, 18.

17. Abrams, D. S., Prausnitz, J. M., (1975), “Statistical Thermodynamics of Liquid Mixtures: A New Expression for the Excess Gibbs Energy of Partly or Complete Miscible Systems”, AIChE J.

18. Liao, A., and Tong, Z., (1995), “Synthesis of n-Butyl Acetate Catalyzed by Amberlyst”, Chemical Reaction Engineering and Technology (Huaxue Fanying Gongcheng Yu Gongy), 11 (4), 406–408.

19. Liao, S., and Zhange, X., (1997), ”Study on Esterification Catalyzed by Solid Acid Catalyzed by Solid Acid Catalyst (II). Kinetics and Mechanism of Liquid Phase Esterification”, Journal of South China University of Technology (Natural Science), 25 (11), 88–92.

20. Janowsky, R., Groebel, M., and Knippenberg, U., (1997), “Nonlinear Dynamics in Reactive Distillation—Phenomena and Their Technical Use” Final Report FKZ 03 D 0014 B0, Huels Infractor GmbH: experSCience, Marl.

21. Zheng, R., and Zeng, J., (1997), “Catalytic Synthesis of Butyl Acetate by Using Srong Acidic Cation-Exchange Resin”, Journal of Xiamen University (Natural Science), 36 (1), 67–70.

22. Zheng, R., and Zeng, J., (1998), “Kinetics of Esterification of Acetic Acid and n-Butanol on Strong Cation-Exchange Resin”, Journal of Xiamen University (Natural Science), 37 (2), 224–227.

23. Steinigeweg, S., and Gmehling, J., (2002), “n-Butyl Acetate Synthesis via Reactive Distillation: Thermodynamic Aspects Reaction Kinetics Pilot Plant Experiments and Simulation Studies”, Industrial and Engineering Chemistry Research 41, 5489–5490.

24. Gangadwala, J., Mankar, S., Mahajani, S., Kienle, A. and Stein, E., (2003), ”Esterification of Acetic Acid with n-Butanol in the Presence of Ion-Exchange Resins as Catalysts,” Ind. Eng. Chem. Res., 42, 2146.

25. Kathel, P., and Amiya, K. J., (2010), ”Dynamic Simulation and Nonlinear Control of a Rigorous Batch Reactive Distillation”, ISA Transactions 49 130137.

26. Löning, S., Horst, C., and Hoffmann, U., (2000), “Theoretical Investigations on the Quaternary System n-Butanol, Butyl Acetate, Acetic Acid and Water” Chem. Eng. Technol. 23, 9, 789-797.

27. Tang, Y., T., Chen, Y., W., Huang, H., P., and Yu, C., C., (2005), “Design of Reactive Distillations for Acetic Acid Esterification” AIChE Journal, 51(6), 1683-1699.

Table (1) Binary interaction parameters for the UNIQUAC model (25)

Component .

ri q (cal/mol) i (cal/mol) Acetic acid 2.2024 2.072 n-butanol 3.4543 3.052 Butyl acetate 4.8274 4.196 Water 0.92 1.4

Table (2) Binary interaction parameters for the UNIQUAC model P

(25)P.

UR11R=0 UR12R=-131.7686 UR13R=-298.4344 UR14R=-343.593 UR21R=148.2833 UR22=R0 UR23R=82.5336 UR24R=68.0083 UR31R=712.2349 UR32R=24.6386 UR33R=0 UR34R=685.71 UR41R=527.9296 UR42R=581.1471 UR43R=461.4747 UR44R=0

Table(3) reaction kinetic parameters P

(24) ofK 3.3856×10P

6 Pmol/gm.s

fE 70.660×10P

3 PJ/mol

oaK 3.3405

aE -3.5817×10P

3 PJ/mol

catM 2000 gm/tray

Table (5) Singular points of the Butyl Acetate system

Point Name T [o Composition C] BuOH HAc BuAc H2O 1 Unstable node 84.6502 0 0 0.2652 0.7348 2 Saddle 91.1934 0 0 0.2766 0.7234 3 Saddle 91.8907 0.2288 0 0 0.7712 4 Saddle 99.9998 0 0 0 1 5 Saddle 116.1545 0.7004 0 0.2996 0 6 Saddle 117.8648 0 1 0 0 7 Saddle 117.7376 1 0 0 0 8 Stable node 118.2930 0.4127 0.5873 0 0 9 Stable node 125.9473 0 0 1 0

Table (4) Values of Antoine constants, molecular weights and boiling points (24)

Component A B C Mwt

(gm/mol) Boiling Point

(P

oPC)

Acetic acid 22.1001 -3654.62 -45.392 74. 123 118.1 n-Butanol 21.9783 -3080.66 -96.150 60. 052 117.9 Butyl acetate 21.07637 -3151.09 -69.150 116. 160 126.3 Water 23.2256 -3835.18 -45.343 18. 015 100 Antoine equation

CTBA)Pln(+

+= where P P

oP in Pa and T in K.

Figure (1) RCM determination set-up

Figure (2) Flow chart of reactive residue curve map prediction program

Select initial composition for quaternary system

Enter parameters for Vapor pressure, Activity coefficient and reaction kinetics

Integrate the set of DAEs in the positive direction until maximum boiling point is reached

Integrate the set of DAEs in the negative direction until minimum boiling point is reached

Enter the number of starting points Np

If N= Np

N=N+1

Plot the result in 3D plot

No

Yes

00.2

0.40.6

0.8

00.2

0.40.6

0 8

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

100

% B

utyl

ace

tate

(126

.3 C

)

Butyl acetate126.3 C

n-Butanol117.9 C

Acetic acid 118.1 C

Water100 C

Un-stable Az.0.00 % Acetic acid0.00 % n-Butanol

25.80 % Butyl acetate74.20 % Water

104.38 C

Figure (3) Non-reactive residue curve map (Da=0, P=1 atm)


00.2

0.40.6

0.8

00.2

0.40.6

0.8

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

100

% B

utyl

ace

tate

(126

.3 C

)Butyl acetate

126.3 C

Water100 C

n-Butanol117.9 C

Acetic acid 118.1 C



84.65 C

Stable Az.58.92 % Acetic acid41.08 % n-Butanol

0.00 % Butyl acetate 0.00 % Water

118.30 C

00.2

0.40.6

0.81

00.2

0.40.6

0.81

n-Butanol117.9 C

Acetic acid 118.1 C


Water100 C



117.13 C

00.2

0.40.6

0.81

00.2

0.40.6

0.81


Water100 C

n-Butanol117.9 C

Acetic acid 118.1 C



134.74 C



00.2

0.40.6

0.81

00.2

0.40.6

0.81

Acetic acid 118.1 C

n-Butanol117.9 C


Water100 C



84.68 C

00.2

0.40.6

0.81

00.2

0.40.6

0.81

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

100 % Acetic acid (118.1 C)100 % Butanol (117.9 C)

100

% B

utyl

ace

tate

(126

.3 C

)

Acetic acid 118.1 C

n-Butanol117.9 C


Water100 C



85.57 C

Figure (7) Reactive residue curve map (Da=0.01, P=1 atm)


00.2

0.40.6

0.81

00.2

0.40.6

0.81

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1


100

% B

utyl

ace

tate

(126

.3 C

)

Acetic acid 118.1 C

n-Butanol117.9 C


Water100 C



84.79 C

00.2

0.40.6

0.81

00.2

0.40.6

0.81

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1


100

% B

utyl

ace

tate

(126

.3 C

)

Acetic acid 118.1 C

n-Butanol117.9 C


Water100 C



84.84 C



00.2

0.40.6

0.81

00.2

0.40.6

0.81

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1


100

% B

utyl

ace

tate

(126

.3 C

)

Acetic acid 118.1 C

n-Butanol117.9 C


Water100 C

Un stable Az.26.53 % Butyl acetate

73.47 % Water84.29 C

00.2

0.40.6

0.81

00.2

0.40.6

0.81

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1


100

% B

utyl

ace

tate

(126

.3 C

)

Acetic acid 118.1 C

n-Butanol117.9 C


Water100 C



85.11 C



00.2

0.40.6

0.81

00.2

0.40.6

0.81

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

100 % Butanol (117.9 C)100 % Acetic acid (118.1 C)

100

% B

utyl

ace

tate

(126

.3 C

)

Acetic acid 118.1 C

n-Butanol117.9 C


Water100 C



85.57 C

00.2

0.40.6

0.81

00.2

0.40.6

0.81

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

100 % Butanol (117.9 C)100 % Acetic acid (118.1 C)

100

% B

utyl

ace

tate

(126

.3 C

)

Acetic acid 118.1 C

n-Butanol117.9 C


Water100 C



86.01 C



00.2

0.40.6

0.81

00.2

0.40.6

0.81

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1


100

% B

utyl

ace

tate

(126

.3 C

)

Acetic acid 118.1 C

n-Butanol117.9 C


Water100 C



84.84 C

00.2

0.40.6

0.81

00.2

0.40.6

0.81

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

100 % A ti id (118 1 C)

100

% B

utyl

ace

tate

(126

.3 C

)

Water100 C


Acetic acid 118.1 C

n-Butanol117.9 C



86.83 C



خرائط منحنيات المتبقي التفاعلي لنظام رباعياستنباط

د. زيدون محسن شكور

\ الجامعة التكنولوجية \قسم الهندسة الكيمياوية بغداد

[email protected]

لنظام رباعي بوجود تفاعل. منحني المتبقي يتصرف مثل برج )RCMفي هذه الدراسة تم استنباط لمنحنيات المتبقي (

من تفاعل كحول البيوتانول مع حامض والماء أنتاج خالت البيوتيل دراسةتقطير مكون من مرحلة اتزان واحدة. تم

منحنيات المتبقي التفاعلي.تم استخدام موديل بناءاالسيتك. حيث تم استخدام كل من اتزان بخار-سائل وحركيات التفاعل ل

UNIQUAC اليجاد معامل الفعالية في الطور السائل بينما اعتبر الطور الغازي مثالي. التمثيل الرياضي يتضمن

) المدمج في برنامج ode15sمجموعة من المعادالت الرياضية واربع معادالت تفاضلية وقد تم حلها باستخدام األمر (

تم التوصل من خالل البحث الى ان وزن العامل المساعد يعتبلر اهم عامل مؤثر على شكل منحنيات المتبقي ماثالب.

تم مقارنة النتائج المستحصلة من البرنامج المطور مع النتائج المنشورة في األدبيات لنفس التفاعل حيث تم التفاعلي.

التوصل إلى كفاءة البرنامج المطور للحصول على منحنيات المتبقي ألي نظام غير مثالي مكون من إي عدد من المركبات.

:الكلمات الدليلية

الب ، خالت البيوتيل.ت خرائط منحنيات المتبقي ، التفاعلي ، ما

Prediction Reactive Residue Curve Map (rRCM) for ... m 2 x.pdfReactions can lead to the...

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Transcript of Prediction Reactive Residue Curve Map (rRCM) for ... m 2 x.pdfReactions can lead to the...