Chemical Engineering Science 54 (1999) 2839}2847
Multiple reactions in catalytic distillation processes for the production
of the fuel oxygenates MTBE and TAME: Analysis by rigorous model
and experimental validation
Kai Sundmacher , Gerd Uhde, Ulrich Ho!mann*
Institut fuK r Chemische Verfahrenstechnik, Technische UniversitaK t Clausthal, Leibnizstrasse 17, D-38678 Clausthal-Zellerfeld, Germany
Abstract
The combination of a chemical reaction and a distillative separation in one apparatus shows several advantages compared to the
separately performed processes. The present contribution presents a comparative study of several possible models of di!erent
complexity for this reactive distillation process. These models consider multiple chemical main and side reactions which are always
present in the industrial production of the fuel ethers MTBE and TAME. Due to the strong nonideality of the reaction mixtures,
liquid-phase activities are used for the formulation of the reaction kinetics. The simulated results were experimentally validated in two
packed laboratory-scale columns. It can be shown that the consideration of side reactions and the modelling of internal catalyst
phenomena play an important role for the interpretation of the experimental results. The comparison of a rate-based model and
a Murphree equilibrium stage model shows that the latter one with a lower complexity yields equivalent model predictions for the
MTBE-system. 1999 Elsevier Science Ltd. All rights reserved.
Keywords: Reactive distillation; Packed column; Fuel ethers; Multiple reactions; Modelling; Experimental validation
1. Introduction step of both processes impurities are removed from the
mixture of the reactive ole"ns and inert hydrocarbons in
Reactive distillation is a multifunctional reactor con- a feed wash. In the "rst "xed-bed reactor the main part of
cept which combines a distillative separation with a the overall conversion of reactive ole"ns is attained.
chemical reaction, preferably heterogeneously catalysed. This reactor is "lled with an acid ion exchange resin
The expected bene"ts from such a synergetic interaction as catalyst. For the further increase of the ole"n conver-
of two unit operations in one column are an enhanced sion a second reactor is necessary in the common indus-
conversion in excess of chemical equilibrium, an in- trial process. In a fourth process step the product
creased selectivity, the avoiding of hot spots by using TAME is isolated via distillation from hydrocarbons
heat of reaction for distillation and the overcoming of and methanol. This unreacted methanol is removed from
azeotropic limitations (e.g. Sundmacher and Ho!mann, unreacted and inert hydrocarbons via an extraction
1996). step and separated from water via distillation. Then,
Fig. 1 shows the #ow scheme of a common industrial methanol can be recycled to the "xed-bed reactor. The
process (Obenaus and Droste, 1980) for the production of process which involves a reactive distillation combines
the fuel ethers tert-amyl-methylether (TAME) or methyl- three process steps of the common process and, by this,
tert-butylether (MTBE) in comparison to a possible pro- signi"cant savings of energy and investment costs are
cess in which a reactive distillation is involved. In the "rst achieved.
In the last two years, quite a number of papers were
published on design principles (e.g. Bessling et al., 1997;
Espinosa et al., 1996; Nisoli et al., 1997; Sneesby et al.,
*Corresponding author.
1997), modelling and operation (e.g. Alejski and Duprat,
Present address: Max-Planck-Institute for Dynamics of Complex
1996; Bock et al., 1997; Hauan et al., 1997; Isla and
Technical Systems, Leipziger Strasse 44, ZENIT-Building, D-39120
Magdeburg, Germany. Irazoqui, 1996; Sundmacher and Ho!mann, 1996) of
0009-2509/99/$ } see front matter 1999 Elsevier Science Ltd. All rights reserved.
PII: S 0 0 0 9 - 2 5 0 9 ( 9 8 ) 0 0 5 2 0 - X
2840 K. Sundmacher et al./Chemical Engineering Science 54 (1999) 2839}2847
Fig. 1. (a) Flow scheme of a conventional process for the production of fuel ethers. (b) Flow scheme of a process including a reactive distillation
column for the production of fuel ethers.
reactive distillation columns. Most of these consider only synthesis, the fuel ether is formed from methanol and the
a single desired reaction taking place. In contrast to that, two isomers 2-methyl-1-butene (2MB1) and 2-methyl-2-
in the present contribution multiple main and side reac- butene (2MB2). The latter two components simulta-
tions in catalytic distillation columns are theoretically neously isomerise, forming a reaction triangle with the
analysed and experimentally validated. This is of remark- two TAME synthesis reactions (Oost and Ho!mann,
able relevance for the application of reactive distillation 1996). The production of MTBE from methanol (MeOH)
columns under industrial conditions where, in most and isobutene (IB) is accompanied by the undesired par-
cases, at least one side reaction is involved. allel formation of isobutene-dimers (DIB) which deacti-
vate the catalytic distillation packing.
In both reaction systems additional side reactions can
2. Considered reaction systems occur. One of these reactions is the etheri"cation reaction
of methanol to dimethylether (DME):
For our analysis the syntheses of the fuel ethers MTBE
2MeOH DME#H O. (1)
and TAME were chosen as two examples of high indus-
trial importance. The reaction schemes of these two Water can react in a consecutive reaction with an ole"n
reaction systems are depicted in Fig. 2. In case of TAME- to the appropriate alcohol. In case of the MTBE-system
K. Sundmacher et al./Chemical Engineering Science 54 (1999) 2839}2847 2841
ing expressions to calculate the equilibrium constants of
the two TAME-formation reactions:
4273.5 K
K "1.057 10 exp , (3)
Ä…
3374.4 K
K "1.629 10 exp . (4)
Ä…
To obtain a kinetic model of the reversible MTBE-
reaction the chemical equilibrium has to be considered,
too. For the simulations presented here we used the
correlation published by Reh"nger and Ho!mann (1990)
for the temperature dependence of the equilibrium con-
stant K .
The vapor}liquid-phase equilibria are calculated as-
suming an ideal vapor phase. Thus, the phase equilibria
can be calculated with the liquid-phase activity coe$-
cients and the vapor pressures of the pure compo-
nents p :
x ) (x , Ä…) ) p (Ä…)"x )p. (5)
The equations and coe$cients used for the calculation of
the pure component vapor pressures p are summarized
Fig. 2. Schemes of the considered reaction systems.
in Table 1.
For the estimation of the activity coe$cients in the
tert-butanol (TBA) results from the reaction of isobutene TAME-system the Wilson model was applied. This
and water: model predicts a homogeneous mixture of methanol with
the C5 hydrocarbons for the whole concentration range
IB#H O TBA. (2)
at boiling temperature. This is in agreement with the
experimental data. In contrast to that the UNIQUAC-
model predicts phase splitting, and therefore it is not an
3. Chemical and phase equilibria adequate model for the TAME-system. The activity coef-
"cients of the MTBE-system are calculated from the
For the formulation of the kinetics of the reversible UNIQUAC-model. The parameters of both activity coef-
TAME-reactions three coupled chemical equilibria have "cient models, Wilson and UNIQUAC, are summarised
to be considered. Rihko et al. (1994) proposed the follow- in Tables 2 and 3.
Table 1
Parameters for vapor pressure correlations
Component A B C D Ä… [K] p [bar] Eq. no. Ref.
MeOH !8.5480 0.7698 !3.1085 1.5448 512.6 80.9 (I) Reid et al. (1987)
IB !6.9554 1.3567 !2.4522 !1.4611 417.9 40.0 (I) Reid et al. (1987)
MTBE !7.8252 2.9549 !6.9408 12.174 497.2 34.8 (I) Reid et al. (1987)
1-Butene !6.8820 1.2705 !2.2628 !2.6163 419.6 40.2 (I) Reid et al. (1987)
DIB 9.1168 2932.2 !52.535 ** * (II) Mohl et al. (1996)
2MB1 !6.8299 0.7266 !2.1536 !3.6223 465.0 34.5 (I) Reid et al. (1987)
2MB2 !7.7144 1.9595 !3.1571 !2.2252 470.0 34.5 (I) Reid et al. (1987)
TAME 9.1556 2782.4 !55.243 ** * (II) Cervenkova and
Boublik, (1984)
nP !7.2894 1.5368 !3.0837 !1.0246 469.7 33.7 (I) Reid et al. (1987)
p Ä…
(I) ln "(1!x) [A x#B x #C x #D x ] with x"1! .
Ä…
p
(II) ln (p )"A !B /[Ä…#C ] Remark: p in (bar); Ä… in (K).
DIB"2, 4, 4-trimethyl-1-pentene.
2842 K. Sundmacher et al./Chemical Engineering Science 54 (1999) 2839}2847
Table 2
Wilson interaction parameters for activity coe$cient calculation in the TAME reaction system from Mohl et al. (1996)
Component i Component j
MeOH 2MB1 2MB2 TAME n!P
( ! ) (kJ/mol)
MeOH 0 9.7723 10.147 4.8263 11.749
2MB1 1.3765 0 0.47880 !0.61175 0.32674
2MB2 0.96881 !0.47794 0 !0.38604 0.36228
TAME !0.17700 0.95133 0.71233 0 1.1439
nP 1.9467 !0.19418 !0.26549 !0.44784 0
Table 3
UNIQUAC parameters for activity coe$cient calculation in the MTBE reaction system from Reh"nger and Ho!mann (1990)
Component i q r Component j
MeOH IB, 1-Butene MTBE TMP1
( ! ) (kJ/mol)
MeOH 1.432 1.431 0 !0.2941 !0.7320 !0.05964
IB, 1-butene 2.684 2.920 5.873 0 0.4340 0.2121
MTBE 3.632 4.068 3.897 !0.2047 0 !0.1424
DIB 4.920 5.616 5.873 !0.1637 0.3804 0
Mohl et al. (1996).
DIB - 2, 4, 4-trimethyl-1-pentene.
4. Reaction kinetics mmol 89.5 kJ/mol
k (Ä…)"2.576 exp !
seq R
4.1. TAME-kinetics
1 1
! . (7)
The microkinetics of the heterogeneously catalyzed
Ä… 333 K
liquid-phase TAME-formation are formulated according
Eq. (6) implies that the isomerization of the C5-ole"ns
to Oost and Ho!mann (1996). These authors derived
runs much faster than the two TAME-formation reac-
a Langmuir}Hinshelwood rate expression in terms of
tions and therefore the chemical equilibrium of the
the liquid-phase activities. The two isomeric ole"ns
isomerization reaction is established. It should be men-
2M1B and 2M2B show ideal mixture behavior in the
tioned that this is in contrast to the work of Rihko et al.
liquid phase. Therefore they can be lumped together
(1997), who found that the isomerization reaction is
to one isoamylene (IA) fraction. Then, based on the
much slower than expected by Oost and Ho!mann
assumptions that the TAME-formation reactions of the
(1996). Therefore, additional kinetic experiments are ne-
absorbed species are rate-determining and that nearly all
cessary to clarify the importance of the isomerization
active sites are occupied by methanol molecules, the
reaction kinetics.
following rate equation for the net turn-over-number
results:
4.2. MTBE-kinetics
a 1
r "k (Ä…) ) !
For the microkinetic description of the heterogeneous-
a K (Ä…)
ly catalyzed liquid-phase MTBE-formation, the well-es-
tablished rate expression of Reh"nger and Ho!mann
1 a
(1990) is used. These authors introduced activity-based
# . (6)
K (Ä…) a
Langmuir isotherms to formulate the sorption equilibria
of the components between the liquid phase and the
The reaction rate constant k is given by the fol- catalyst gel phase. If the reaction of sorbed species is
lowing Arrhenius equation: the r.d.s. and if methanol is sorbed highly selective in the
K. Sundmacher et al./Chemical Engineering Science 54 (1999) 2839}2847 2843
ion-exchange resin, the following microkinetics result:
a 1 a
r "k (Ä…) ! . (8)
a K (Ä…) a
The temperature dependence of the rate constant is given
by the Arrhenius equation
mmol !92.4 kJ/mol 1 1
k (Ä…)"15.5 exp ! .
seq R Ä… 333 K
(9)
The dimerization of isobutene forms the two isomers 2, 4,
4-trimethyl-1-pentene and 2, 4, 4-trimethyl-2-pentene.
They were lumped to one pseudo-component di-
isobutene (DIB). According to Haag (1967) the formation
Fig. 3. Simulated reaction rates and component activity pro"les within
of DIB follows a Langmuir}Rideal mechanism:
a catalyst particle for the MTBE system.
Adsorption: IB#S8IB ) S. (10)
Surface reaction: IB ) S#IB && DIB ) S. (11)
5. Modelling of packed sections in a reactive distillation
column
Desorption: DIB ) S 8 DIB#S. (12)
A detailed comparative study of several possible react-
The second reaction step, Eq. (11), is assumed to be rate
ive distillation models of di!erent complexity was
determining and irreversible. At low methanol concen-
performed. The model family consists of four di!erent
trations, where this reaction takes place, only methanol
models which are illustrated in Fig. 4.
and isobutene molecules are absorbed in the ion-
Models (1) and (3) assume that vapor}liquid equilib-
exchange resin. From these assumptions the following
rium is established between the bulk phases. Models
rate equation is obtained:
(2) and (4) are rate-based, i.e. the multicomponent
a K
mass transport between the vapor phase and liquid phase
r "k (Ä…) ) where K, .
Ka #a K is taken into account. The interfacial transport is
modelled on the basis of a matrix solution of the general-
(13a,b)
ized Maxwell}Stefan equations (Taylor and Krishna,
1993).
As can be seen from Eq. (13b), the parameter K is de"ned
Furthermore, the models can be distinguished with
as the ratio of the sorption constants of methanol and
respect to the consideration of internal catalyst mass
isobutene. By "tting of published experimental data this
transport phenomena. In models (1) and (2) the solid
parameter was estimated to K"500. The rate constant
catalyst is treated quasihomogeneously, i.e. at each cata-
k was determined from the experimental rate data of
lytically active site the liquid bulk phase composition is
Haag (1967):
mmol !66.7 kJ/mol 1 1
k (Ä…)"1270 exp !
seq R Ä… 333 K
(14)
A detailed analysis of the simultaneous mass transport
and reaction phenomena inside the porous catalyst body
(Uhde et al., 1998) revealed that, for low methanol bulk
concentrations, the dimerization reaction of isobutene
will occur in the inner core of the catalyst where the
MTBE-formation rate vanishes. This is illustrated in
Fig. 3 for the case of a spherical catalyst body.
This knowledge was used to calculate the e!ective rate
of the side reaction with the help of a modi"ed catalyst
model of Sundmacher and Ho!mann (1994) which ac-
counts for the e!ect of internal mass transport resistances
Fig. 4. Model family for heterogeneously catalysed reactive distillation
on the etheri"cation macrokinetics. process.
2844 K. Sundmacher et al./Chemical Engineering Science 54 (1999) 2839}2847
present. Models (3) and (4) include possible mass trans- Table 4
Column con"guration and catalyst properties
port resistances inside the catalyst. These resistances are
treated via the catalyst e!ectiveness factor concept based
TAME MTBE
on the model of Sundmacher and Ho!mann (1994).
Models (1) and (3) consist of
Column H (m) 0.547 0.510
H (m) 0.547 0.510
the mass balances of the components for a packed
d (m) 0.076 0.054
column section,
Catalyst 0.49
the above formulated chemical microkinetics,
c [eq(H )l ] 1.2
the overall energy balance for a packed column sec- Shape Raschig rings
d h t (mm )9 9 2
tion,
the vapor}liquid phase equilibria; any deviation from
phase equilibria is taken into account by a Murphree-
e$ciency stage approach.
The noncatalytic packing consists of the same porous
glass rings without the ion-exchange polymer. In both
In addition to this, models (2) and (4) contain
columns the packing is distributed in an upper catalytic
part and a lower noncatalytic part. The feed point of the
the mass balances of the components in the vapor
premixed reactants and the inert component was in the
phase,
the mass balances of the components at the va- middle between the two packings. Table 4 gives an over-
view of the column geometry and the catalyst properties.
por}liquid interface.
For all simulations presented below we assumed a heat
The corresponding formulation of these balance equa-
loss coe$cient of 2 W/(m K) through the column wall.
tions can be found in detail elsewhere (Sundmacher and
This value is based on a comparison of simulated results
Ho!mann, 1996). The steady-state solution of the model
with various experimental data from our reactive distilla-
equations is obtained by introducing accumulation terms
tion laboratory columns (Gravekarstens, 1998). All simu-
to the component mass balances (&&False Transient
lations were carried out with a number of 10 packed
Method''). The other balance equations are treated alge-
column sections. The simulations with model (1) are
braically. This leads to a set of di!erential and algebraic
carried out with a Murphree-e$ciency of 0.8. This
equations. For their numerical integration the extrapola-
value coincides with the experimental "ndings of Bessling
tion integrator LIMEX (Deu#hard et al., 1987) was
et al. (1998). These authors investigated the separation
applied.
e$ciency of the catalytic Raschig rings which were used
for the discussed reactive distillation experiments. They
found that the number of theoretical separation stages
6. Simulated results and experimental validation per meter is about 8 for the vapor load range established
in our columns (vapor F-factor: F"0.3 Pa ....
Based on the model approach described above, 0.9 Pa ). Since the total height of the column packing is
detailed simulations were carried out to investigate about 1 m the overall Murphree-e$ciency stage factor of
the in#uence of selected operating parameters (re#ux the 10 simulated stages is 0.8.
ratio r, reboiler heat input Q , pressure p) on the First, simulated and experimental results of the
process performance (conversion, yield, selectivity) for TAME-reaction system are presented. Due to the fact
the TAME reaction triangle and the MTBE parallel that the TAME-formation rate is more than ten times
reactions. lower than the MTBE-formation rate, mass transfer re-
The reactive distillation experiments are performed in sistances inside the catalyst bodies are negligible, and
two di!erent stainless-steel laboratory columns with un- therefore a quasihomogeneous approach should be su$-
structured Raschig ring packings. Both columns can be cient to describe the TAME-reactive distillation column.
operated at elevated pressures up to p"1 MPa and In Fig. 5a calculated and measured temperature pro-
temperatures up to Ä…"2003C. The MTBE reaction sys- "les along the column are compared, and in Fig. 5b the
tem was investigated in a column with 54 mm inner corresponding liquid-phase compositions are depicted.
diameter, and the experiments for the TAME reaction The two reactive isoamylene isomers 2M1B and 2M2B
system were performed in a larger column with 76 mm and the inert solvent n-pentane are lumped together to
inner diameter. The catalytically active packing consists one single C5-fraction. The simulated results were ob-
of 9 9 mm porous glass rings with a strong acidic ion tained with the vapor}liquid nonequilibrium model (2).
exchange resin inside the pores. This catalyst is an in- Both "gures show a good agreement between simulated
house development of our institute (Kunz and Ho!mann, and experimental data. The bottom product contains no
1995). The ion exchange capacity of this catalyst per methanol and the composition of the distillate is domin-
column volume is about 0.6 eq(H )/l. ated by the existence of the binary azeotrope between
K. Sundmacher et al./Chemical Engineering Science 54 (1999) 2839}2847 2845
Fig. 6. Experimental and simulated composition path for TAME react-
ive distillation column with high isoamylene content in feed mixture;
experimental conversion of isoamylenes: X "39%; experimental sel-
ectivity w.r.t. TAME: S "88%.
S "88%. Note that the dimers (12 mol% in reboiler
liquid) are lumped together with TAME in the concen-
tration triangle of Fig. 6.
Fig. 7a depicts experimental and simulated temper-
ature pro"les of the MTBE-system. Two models are used
to simulate the experimental results. Model (1) is
a quasihomogeneous approach which accounts for the
main reaction only. The parallel occurrence of the dimer-
ization of isobutene can not be described by this
approach since this requires a catalyst model which ac-
Fig. 5. (a) Experimental and simulated temperature pro"les for TAME counts for mass transport resistances inside the catalytic
reactive distillation column. (b) Experimental and simulated composi-
rings. Therefore, model (1) underestimates the temper-
tion path for TAME reactive distillation column; experimental conver-
ature in the reboiler where the high boiling by-product
sion of isoamylenes: X "37%; experimental selectivity w.r.t. TAME:
DIB is mainly located. The more detailed model (3)
S +100%.
includes the side reaction and predicts a higher temper-
ature in the reboiler. Fig. 7b shows the corresponding
methanol and the C5-components. The concentration of simulated liquid-phase composition path and some ana-
the desired product TAME in the bottom is not very lyzed liquid samples. The component isobutene and the
high. This is caused by a relatively low reaction rate and inert component 1-butene are lumped together to one
a high re#ux ratio which forces considerable amounts of C4-fraction. The analyzed experimental samples clearly
C5-components to leave the column at the bottom. revealed that a considerable amount of dimers is formed
According to the TAME-reaction kinetics, Eq. (6), under the given process conditions. Therefore in the
higher etheri"cation rates in the catalytic column section lower part of the column, signi"cant deviations between
should be achievable at a higher content of isoamylenes the experimental concentrations and those, which are
and a lower content of methanol in the feed mixture. predicted by model (1), exist.
In correspondence to this, Fig. 6 shows the liquid- Model (3) predicts a composition of the reboiler liquid
phase composition path for an experiment with which is in good agreement with the experimental data.
a changed feed composition and lower re#ux ratio. In The compositions in the upper part of the column (com-
fact, the TAME content in the bottom is much higher position trajectory near the C4 corner of the tetrahedron)
than in Fig. 5b. The conversion of isoamylenes slightly are predicted quite well by both models. In a previous
increased from X "0.37 (exp. in Fig. 5b) to X "0.39 work, Sundmacher et al. (1997) had already shown that
(exp. in Fig. 6) which is mainly due to the high content of the most complicated model (4) yields nearly the same
isoamylenes in the feed. However, by the undesired results as the much simpler equilibrium stage model (3).
formation of dimers from isoamylenes, the selectivity As a consequence, an equilibrium stage approach is su$-
w.r.t. TAME decreased from S +100% to cient for the adequate description of the MTBE process.
2846 K. Sundmacher et al./Chemical Engineering Science 54 (1999) 2839}2847
Acknowledgements
The authors wish to thank the Volkswagen-Stiftung in
Germany for "nancial support of this research work
within the project &&Modellierung der Integration von Stof-
ftrennprozessen und komplexen Reaktionsnetzwerken''.
Notation
a liquid-phase activity of component i
c ion-exchange capacity related to catalyst vol-
ume, eq(H )/l
d inner column diameter, m
d outer diameter of ring shaped catalyst, mm
F feed mass #ow rate, kg/h
h height of ring shaped catalyst, mm
H height of purely distillative column section, m
H height of catalytic column section, m
k reaction rate constant, mol/(eq(H ) s)
K ratio of sorption constants, Eq. (18)
K sorption constant of component i
K activity-based chemical equilibrium constant
of reaction j
p total operating pressure, MPa
p critical pressure, bar
p saturated vapor pressure of component i, bar
Fig. 7. (a) Experimental and simulated temperature pro"les for MTBE
Q reboiler heat input, W
reactive distillation column. (b) Experimental and simulated composi-
r re#ux ratio
tion path for MTBE reactive distillation column.
r rate of reaction j related to catalytically active
sites, mol/(eq(H )s)
R universal gas constant, 8.314 J/(mol K)
7. Conclusions S selectivity w.r.t. TAME
t wall thickness of ring-shaped catalyst, mm
For the simulation of a heterogeneously catalyzed re- Ä… temperature, K
active distillation process several models with di!erent Ä… critical temperature, K
complexity were tested. The simulated results were ex- x mole fraction of component i
perimentally validated for the TAME- and the MTBE-
reaction system in two laboratory-scale columns. In case Greek letters
of TAME-column a fully rate-based nonequilibrium
model was applied successfully. For the MTBE-system it volume fraction of solid catalyst in catalytic
was shown that a Murphree-equilibrium stage model packing section
which includes the calculation of simultaneous mass
transport and reaction phenomena inside the catalytic Subscripts
distillation packing is well applicable. The formation of
high boiling dimers from isobutene and their accumula- DIB DIB reaction (see Fig. 2)
tion in the liquid phase lead to a considerable increase of ISO isomerization reaction of 2M1B and 2M2B
the temperatures in the bottom section of the MTBE- (see Fig. 2)
column. Obviously, it is necessary to account for the side MTBE MTBE formation (see Fig. 2)
reaction in designing a catalytic distillation column for TAME1 TAME formation from 2M1B (see Fig. 2)
this reaction system. TAME2 TAME formation from 2M2B (see Fig. 2)
As a work for the future, the column operating condi-
tions have to be adjusted to optimize the conversion of Superscripts
ole"ns in the reactive distillation process. This process
optimization should be based on the validated models e equilibrium
which are presented in this contribution. F related to the feed
K. Sundmacher et al./Chemical Engineering Science 54 (1999) 2839}2847 2847
< related to the vapor phase Haag, W.O. (1967). Oligomerization of isobutene on cation exchange
resins. Chem. Engng Prog. Symp. Ser., 63, 140}147.
¸ related to the liquid phase
Hauan, S., Hertzberg, T., & Lien, K.M. (1997). Multiplicity in reactive
S related to the solid catalyst
distillation of MTBE. Comput. Chem. Engng, 21, 1117}1124.
Isla, M.A., & Irazoqui, H.A. (1996). Modelling, analysis and simulation
Abbreviations
of a methyl tert-butyl ether reactive distillation column. Ind. Engng
Chem. Res., 35, 2696}2708.
Kunz, U., & Ho!mann, U. (1995). Preparation of catalytic poly-
C4 C4-fraction ("isobutene#1-butene)
mer/ceramic ion exchange packings for reactive distillation col-
C5 C5-fraction ("nP#2M1B#2M2B)
umns. Preparation Catalysts DIB diisobutene (2,4,4-trimethyl-1-pentene#
Mohl, K.D., Kienle, A., & Gilles, E.D. (1996). Personal communication,
2,4,4-trimethyl-2-pentene)
Institut fur Systemdynamik und Regelungstechnik, Universitat
K K
Stuttgart.
IA isoamylene (2M1B#2M2B)
Nisoli, A., Malone, M.F., & Doherty, M.F. (1997). Attainable regions
IB isobutene
for reaction with separation. A.I.Ch.E. J., 43, 374}387.
MeOH methanol
Obenaus, F., & Droste, W. (1980). Huls process: methyl tertiary
K
MTBE methyl-tert-butylether
butylether. Erdol Kohle-Erdgas-Petrochem. Brennsto+chem., 33,
K
nP n-pentane
271}275.
Oost, C., & Ho!mann, U. (1996). The synthesis of tertiary amyl methyl
S active site of catalyst
ether (TAME): microkinetics of the reactions. Chem. Engng Sci., 51,
TAME tert-amyl-methylether
329}340.
TBA tert-butanol
Reh"nger, A., & Ho!mann, U. (1990). Kinetics of methyl tertiary butyl
2M1B 2-methyl-1-butene
ether liquid phase synthesis catalysed by ion exchange resin. Chem.
2M2B 2-methyl-2-butene
Engng Sci., 45, 1605}1626.
Reid, C.R., Prausnitz, J.M., & Poling, B.E. (1987). Ä…he properties of
gases and liquids (pp. 656}732). New York: McGraw-Hill.
Rihko, L.K., Kiviranta-Paakkonen, P.K., & Krause, A.O. (1997). Kin-
K K K
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