U.S. patent application number 09/974059 was filed with the patent office on 2002-06-13 for process for the preparation of tertiary alcohols by the hydration of tertiary olefins in a reactive rectification using a structured multi-purpose packing.
Invention is credited to Gohrt, Axel, Grub, Joachim, Kaminsky, Stefan, Muller, Stephan, Schwegler, Brian.
Application Number | 20020072638 09/974059 |
Document ID | / |
Family ID | 7659573 |
Filed Date | 2002-06-13 |
United States Patent
Application |
20020072638 |
Kind Code |
A1 |
Gohrt, Axel ; et
al. |
June 13, 2002 |
Process for the preparation of tertiary alcohols by the hydration
of tertiary olefins in a reactive rectification using a structured
multi-purpose packing
Abstract
Tertiary alcohols can be prepared by the hydration of tertiary
olefins having the same number of carbon atoms on an acidic ion
exchanger using special structured multi-purpose packings for
heterogeneous reactive rectification. An excellent yield and purity
of the alcohol and an extended service life of the catalyst are
achieved.
Inventors: |
Gohrt, Axel; (Koln, DE)
; Grub, Joachim; (Dormagen, DE) ; Kaminsky,
Stefan; (Dormagen, DE) ; Muller, Stephan;
(Pulheim, DE) ; Schwegler, Brian; (Leverkusen,
DE) |
Correspondence
Address: |
Finnegan, Henderson, Farabow,
Garrett & Dunner, L.L.P.
1300 I Street, N.W.
Washington
DC
20005-3315
US
|
Family ID: |
7659573 |
Appl. No.: |
09/974059 |
Filed: |
October 11, 2001 |
Current U.S.
Class: |
568/896 |
Current CPC
Class: |
C07C 29/04 20130101;
Y02P 20/127 20151101; Y02P 20/10 20151101; C07C 29/04 20130101;
C07C 31/125 20130101 |
Class at
Publication: |
568/896 |
International
Class: |
C07C 029/04 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 12, 2000 |
DE |
10050627.5 |
Claims
1. A process for the preparation of tertiary alcohols by reacting
the corresponding tertiary olefins having the same number of carbon
atoms with water in a heterogeneous reactive rectification in the
presence of an acidic cation exchanger, characterized in that said
process is performed using structured catalytic multi-purpose
packings which have sections serving for material separation and
sections serving as second functionality elements, wherein said
sections serving as second functionality elements have a
compartmental structure in which said acidic cation exchanger is
contained.
2. The process according to claim 1 for the preparation of tertiary
C.sub.4 to C.sub.8 alcohols, preferably C.sub.5, C.sub.6 or C.sub.7
alcohols, especially tertiary amyl alcohol, by reacting the
corresponding tertiary olefins having the same number of carbon
atoms, especially isoamylene.
3. The process according to claim 1 or 2, characterized in that
sulfonated phenol-formaldehyde resins, sulfonated cumarone-indene
condensation products, sulfonated polystyrenes or sulfonated
styrene-divinylbenzene resins in their respective H.sup.+ forms are
employed as acidic cation exchangers.
4. The process according to claim 3, characterized in that
sulfonated styrene-divinylbenzene resins having a degree of
cross-linking (divinylbenzene content) of from 2 to 65% by weight,
preferably from 8 to 25% by weight, are employed.
5. The process according to claim 1, characterized in that the
acidic cation exchangers are loaded with such an amount of total
feed mixture of tertiary olefin and water that a liquid hourly
space velocity (LHSV) of 0.05-1 l of feed mixture per liter of
catalyst per hour, preferably 0.1-0.4 l of feed mixture per liter
of catalyst per hour, is achieved.
6. The process according to claim 1, characterized in that the
amount of water employed is superstoichiometric, equimolar or
substoichiometric, based on the tertiary olefin employed.
7. The process according to claim 6, characterized in that an
excess of water of from 10 to 90 mole percent, more preferably of
from 30 to 70 mole percent, is employed.
8. The process according to claims 2 or 7, characterized in that an
excess of water of from 40 to 50 mole percent, based on the
isoamylene employed, is used for the preparation of tertiary amyl
alcohol from isoamylene and water.
9. The process according to claim 1, characterized in that the
structured multi-purpose packings contains material separation
elements (1) and second functionality elements (2) provided in
alternate layers, wherein the material separation elements have a
profiled surface, and each of the second functionality elements has
two or more closed chambers (3) provided on top of each other and
filled with the acidic cation exchanger, a space being provided
between any two of the chambers, which space is bridged by a
section (6) conducting a liquid, the walls of the preferably
pillow-shaped chambers of the second functionality elements being
constituted of metal-wire cloth.
Description
[0001] The present invention relates to a process for the
preparation of tertiary alcohols by the hydration of tertiary
olefins on an acidic ion exchanger in a reactive rectification
using a structured multi-purpose packing.
[0002] From U.S. Pat. No. 2,813,908, it is already known to hydrate
olefins on styrene-divinyl-benzene polymers containing sulfonic
acid groups. This process is performed at temperatures of from 121
to 218.degree. C. and pressures of up to 211 bar, but when
isobutene is used, it results in an extensive formation of
isobutene polymers.
[0003] Especially known from U.S. Pat. No. 3,257,469 is the
preparation of tertiary amyl alcohol (TAA) on such acidic ion
exchangers containing sulfonic acid groups by the reaction of
isoamylene with a molar excess of water. This is effected, for
example, at a pressure of 35 bar and a temperature of from 66 to
107.degree. C. A proportion of TAA in the reaction product which is
sufficient for industrial purposes is achieved by including
solvents, of which isopropanol and acetone are particularly pointed
out. Thus, this process necessarily comprises the separation of the
included solvent from the reaction mixture.
[0004] U.S. Pat. No. 4,182,920 is a further development of the
previously described process and is also preferably aiming at the
preparation of TAA. A novel feature particularly pointed out is
that the whole feed mixture forms a single homogeneous phase and
part of the isoamylene is fed into a second of a total of at least
two reactors. As the solvent, acetone is particularly pointed out,
and according to the Examples, it is present in an amount of from
60 to 75% by weight of the whole feed. This process is also
performed with excess molar amounts of hydration water.
[0005] DE-A-35 12 518 describes the catalytic hydration of lower
olefins, which are propene and n-butene according to the Examples.
As the reaction parameters, conditions of from 120 to 180.degree.
C. under a pressure of from 40 to 200 bar on a strong ion exchanger
in the presence of excess molar water amounts are selected. The
excess process water is recirculated. Such conditions cause an
increase of the differential pressure in the reactor and thus
pressure surges, which eventually necessitates shut-down of the
continuous reaction. Further, in the hydration of propene, hot
spots in the catalyst bed were observed, which lead to by-products.
To overcome these problems, the mentioned DE-A-35 12 518 describes
the addition of a strong cationic surfactant, for which, however,
the possibility of deactivation of the ion exchanger employed as
catalyst is described in principle.
[0006] DE-A-38 01 275 describes the catalytic hydration of tertiary
C.sub.4 and C.sub.5 olefins at moderately increased temperatures in
the liquid phase. The reaction takes place in two or more serial
tube reactors which contain an acidic ion exchanger. According to
the Examples, the content of dimers in the product mixture is
significantly decreased if from 0.2 to 5% by weight, based on the
tertiary olefin to be hydrated, of tertiary C.sub.4 or C.sub.5
alcohol is added to the feed mixture. In this way, for example, a
product mixture is obtained which has a maximum content of tertiary
amyl alcohol of 26%.
[0007] The use of acidic ion exchanger loaded with an amphoteric
element is described in EP-A-0 325 144. TAA is obtained in a
fixed-bed reactor by the hydration of isoamylene, but the purity in
the reaction mixture is only at up to 27% by weight. The proportion
of dimers in the product mixture is clearly reduced in this
way.
[0008] EP-A-0 325 143 also describes the preparation of TAA by the
hydration of isoamylene on an acidic ion exchanger at a reaction
temperature near the boiling point of isoamylene under the
respectively set reaction pressure. This is effected without the
addition of materials not involved in the reaction, especially
without the addition of solvents. According to the Examples, a TAA
content of up to 51% or a TAA yield of up to 46% is achieved for a
synthesis in a fixed-bed reactor under normal pressure. Can. J.
Chem. Eng. 1993, 71, 821-823, describes the preparation of TAA in a
fixed-bed reactor without the use of a solvent as a phase mediator.
However, a maximum conversion of 12% is achieved.
[0009] All previously described processes share the disadvantage
that the conversion of the process for the hydration of olefins is
limited by the position of the chemical equilibrium. In all reactor
types employed, the reaction space accommodates packings of solid
catalyst particles which have a spherical or pellet-like design,
for example, and are flowed around by the reactants. In the
reactors having such a design, on the one hand, large pressure
drops occur, and on the other hand, a homogeneous temperature
distribution over the reactor cross-section does not occur. Another
disadvantage is that there is no uniform concentration distribution
over the reactor cross-section so that the yield of the desired
final products is not optimum.
[0010] In contrast, the principle of reactive rectification has
established as a method for achieving high conversions in
thermodynamically limited material conversions. It is based on
rectification running parallel with the reaction, whereby the
higher boiling products come down in the column and are thus
removed from the equilibrium. In addition, the heat dissipation in
exothermic reactions can thus be controlled by the evaporation of
the more volatile components, and the desired reaction temperature
can be adjusted through the overall pressure.
[0011] The preparation of tertiary alcohols, especially tertiary
amyl alcohol and tertiary butyl alcohol, by the hydration of the
corresponding tertiary olefins by reactive rectification in the
presence of an acidic ion exchanger is described in EP-A-0 415 310.
In this case, the acidic ion exchanger is provided in a multitude
of bags of a tissue band which is connected with a mesh wire
structure of stain less steel for support, wherein the tissue band
and the mesh wire structure are helically wound. The tissue band
with the bags preferably consists of glass fibers. A drawback in
this process is the fact that very different and in part little
satisfactory results are obtained depending on the olefin employed
and on the reaction conditions. For the conversion of isoamylene,
for example, contents of only about 18 or 27% by weight of tertiary
amyl alcohol are achieved in the bottoms of the column. Exact
conversions or yields are not stated.
[0012] Ind. Eng. Chem. Res. 1997, 36, 3845-3853, also describes the
synthesis of TAA with the catalytic packing described in EP-A-0 415
310 through a reactive rectification. Although high conversions,
based on the isoamylene employed, are evidently achieved, the great
disadvantage of poor reproducibility is present here too. A
variability of .+-.20% is stated.
[0013] The above described wound bodies employed for the hydration
of olefins by reactive rectification in EP-A-0 415 310 and Ind.
Eng. Chem. Res. 1997, 36, 3845-3853, have some disadvantages: Due
to the poor mixing and homogenizing properties of the wound bodies,
there is no radial temperature and concentration equilibration over
the column cross-section, on the one hand. On the other hand, due
to the non-ordered flow form of the educts, products and
by-products, a relatively large pressure drop over the packing
occurs.
[0014] It has been the object of the present invention to provide a
process which especially enables the preparation of tertiary
alcohols by the hydration of the corresponding tertiary olefins
with a high and reproducible conversion, with high purity of the
alcohol in the reaction mixture, and a long service life of the
catalyst employed.
[0015] The present invention relates to a process for the
preparation of tertiary alcohols by reacting the corresponding
tertiary olefins having the same number of carbon atoms with water
in a heterogeneous reactive rectification in the presence of an
acidic cation exchanger, characterized in that said process is
performed using structured catalytic multi-purpose packings which
have sections serving for material separation and sections serving
as second functionality elements, wherein said sections serving as
second functionality elements have a compartmental structure in
which acidic cation exchangers are contained.
[0016] As compared to the known processes described above for the
preparation of tertiary alcohols by reactive rectification, the
process according to the invention is characterized in that the
structured catalytic multi-purpose packings enable a clearly
improved material exchange between gas/liquid in the sections
serving for material separation and ensure a defined high
distillation performance, so that very high yields and purities can
be achieved. Thus, an exact calculation of fluid dynamics is also
enabled.
[0017] The process according to the invention is particularly
suitable for the preparation of tertiary C.sub.4 to C.sub.8
alcohols, preferably C.sub.5, C.sub.6 or C.sub.7 alcohols,
especially tertiary amyl alcohol (TAA), by reacting the
corresponding tertiary olefins having the same number of carbon
atoms, especially isoamylene, with water on an acidic ion
exchanger.
[0018] In the process according to the invention, the tertiary
olefins can be employed either in the form of distillation cuts
containing the corresponding tertiary olefin, or else in an
enriched or pure quality. Isoamylene (mixture of the isomers
2-methylbutene-1 and 2-methylbutene-2) can be employed, for
example, in the form of a C.sub.5 distillation cut which usually
contains at least 5%, preferably at least 10%, by weight of
isoamylene. In principle, such cuts contain, in addition to
isoamylene, straight-chain C.sub.5 olefins, certain amounts of the
corresponding alkanes and some higher and lower hydrocarbon
components. Preferably, an enriched isoamylene stream is used which
usually contains about from 20 to 95% by weight of isoamylene. More
preferably, an essentially pure isoamylene stream is employed which
contains at least 95% by weight of isoamylene. Such an essentially
pure isoamylene stream is obtained, for example, from the cleavage
of tertiary amyl methyl ether (TAME).
[0019] In this reactive rectification, all known acidic cation
exchangers obtainable by the polymerization or copolymerization of
aromatic vinyl compounds followed by sulfonation can be employed as
catalysts for the hydration of the tertiary olefins. Examples of
aromatic vinyl compounds which may be employed for polymerization
or copolymerization include: styrene, vinyl toluene, vinyl
naphthalene, vinylethylbenzene, methylstyrene, vinylchlorobenzene
and vinylxylene. The preparation method for these polymers or
copolymers can be varied broadly. The homo- or copolymerization of
the mentioned monomers can also be effected, for example, in the
presence of polyvinyl compounds for cross-linking: Suitable
polyvinyl compounds which may be used include divinylbenzene,
divinyltoluene or divinylphenyl ether. The homo- or copolymers can
be prepared in the presence or absence of solvents or dispersants
using a wide variety of initiators, such as inorganic or organic
peroxides or persulfates.
[0020] As acidic cation exchangers, sulfonated phenol-formaldehyde
resins, sulfonated cumarone-indene condensation products,
sulfonated polystyrenes or sulfonated styrene-divinylbenzene
resins, above all, employed in their respective H.sup.+ forms, have
proven useful. Preferably, sulfonated styrene-divinylbenzene resins
having a degree of cross-linking (divinylbenzene content) of from 2
to 65% by weight, preferably from 8 to 25% by weight, are employed.
Such acidic cation exchangers are known to the skilled person and
commercially available under many designations.
[0021] The process according to the invention is performed by
loading the acidic cation exchangers with such an amount of total
feed mixture that a liquid hourly space velocity (LHSV) of 0.05-1 l
of feed mixture per liter of catalyst per hour, preferably 0.1-0.4
l of feed mixture per liter of catalyst per hour, is achieved.
[0022] By varying the amount of water employed in the preparation
of tertiary alcohols in a reactive rectification by the process
according to the invention, the product range of the conversion and
the service life of the catalyst can be influenced. The amount of
water employed can be superstoichiometric, equimolar or
substoichiometric, based on the tertiary olefin employed.
Preferably, an excess of water of from 10 to 90 mole percent, more
preferably of from 30 to 70 mole percent, is employed. In
particular, for the preparation of TAA from isoamylene and water,
an excess of water of from 40 to 50 mole percent is used, based on
the isoamylene employed.
[0023] When a lower amount of water is used, dimerization and in
part also oligomerization of the tertiary olefin occur to a higher
extent. The dimers and oligomers formed are very hydrophobic so as
to impede the transport of water to the reaction centers. Since the
water cannot react with the tertiary olefin unimpeded, low
conversions result. In addition, dimers and oligomers deposit in
the pores of the ion exchangers, can be hardly removed from the
catalyst, for example, by rinsing, and thus cause an irreversible
change of the initial morphology of the catalyst. Since part of the
acidic sites of the catalyst are blocked in this way, the activity
and thus the service life of the ion exchangers decrease.
[0024] On the other hand, the excess of water must not be too high
either, since otherwise aqueous and organic phases form in the
bottoms of the reactor of the reactive rectification, which results
in the occurrence of delayed boiling. This leads to an unsteady
operation of the reactor and prevents a good loading of the
catalytic packing and thus a continuous preparation of the tertiary
alcohols.
[0025] The reactive rectification according to the invention for
the preparation of tertiary alcohols yields the tertiary alcohol in
a purity of from 50 to above 99% by weight, preferably from 70 to
95% by weight, more preferably from 85 to 90%. If a further
purification of the tertiary alcohol is desired, the reactive
rectification may be followed by another distillation of the
tertiary alcohol. Using azeotropic distillation with water
separation, purities of above 99% by weight can be achieved. How to
perform such a distillation is sufficiently known to the skilled
person.
[0026] In the process according to the invention, structured
multi-purpose packings can be employed, such as those described,
for example, in U.S. Pat. No. 5,348,710, EP-A-0 428 265 (or the
corresponding U.S. Pat. No. 5,073,236), EP-A-0 396 650 (or the
corresponding U.S. Pat. No. 5,417,938), EP-A-0 950 433 or DE-A-197
01 045, the disclosure of which with respect to the configuration
of structured multi-purpose packings is incorporated herein by
reference.
[0027] In such structured multi-purpose packings, the sections
serving for material separation and the sections serving as second
functionality elements are preferably provided alternately in
layers. As represented, for example, in EP-A-0 950 433, DE-A-197 01
045 and EP 0 396 650 B2 (FIG. 1) and set forth in detail below,
they can be provided as separate juxtaposed elements having
different geometric designs. However, as represented in FIG. 5 of
EP 0 396 650 B2, it is also possible to have a type of parallel
folded layers each having a double coat, the cation exchanger being
filled into the spaces between the double walls.
[0028] Multi-purpose packings structured in this way in accordance
with the invention are commercially available, for example, as
Katapak.RTM. from Gebrueder Sulzer AG or Multipak.RTM. from Montz
GmbH, and are filled with the above described acidic cation
exchanger.
[0029] Particularly useful are the structured multi-purpose
packings as described in EP-A-0 950 433 or DE-A-197 01 045 and
offered by Montz GmbH, containing material separation elements (1)
and second functionality elements (2) provided in alternate layers,
wherein the material separation elements have a profiled surface,
and each of the second functionality elements has two or more
closed chambers (3) provided on top of each other and filled with
the acidic cation exchanger, a space being provided between any two
of the chambers, which space is bridged by a section (6) conducting
a liquid, the walls of the preferably pillow-shaped chambers of the
second functionality elements being constituted of metal-wire
cloth. The material separation elements have a profiled, preferably
corrugated, surface. They are usually formed of metal sheets (7),
preferably of black plate, stainless steel, hastelloy, copper or
aluminum, or structured fabric sheets, for example, based on
plastic materials, such as Teflon. The structure of such
multi-purpose packings is explained in more detail by the following
FIGS. 1-5.
[0030] FIGS. 1a, b and c show a top view of different embodiments
of the structured multi-purpose packing.
[0031] FIGS. 2a and b show a sectional front view of different
embodiments of the second functionality element of the structured
multi-purpose packing having closed chambers.
[0032] FIGS. 3a and b show a sectional side view of different
embodiments of the second functionality element of the structured
multi-purpose packing having closed chambers.
[0033] FIGS. 4a and b show a perspective view of different
embodiments of the structured multi-purpose packing having second
functionality elements and material separation elements.
[0034] FIGS. 5a and b show a front view of different embodiments of
the second functionality element of the structured multi-purpose
packing with disassembled walls.
[0035] As shown in FIGS. 4a and 4b, the material separation
elements (1) and second functionality elements (2) represented in
FIGS. 1a, b and c are provided in alternate layers. The number and
volume of the second functionality elements and the number of the
material separation elements can be varied depending on the
reaction system considered, which is illustratively shown in the
different embodiments in FIGS. 1a, b and c. Therefore, the
residence times and effective surface areas in the second
functionality elements as well as the contact areas in the material
separation elements can be tailored in view of the material system
considered. When mounted, the second functionality elements can be
reinforced by fluid-permeable stabilizing metal sheets (10) as in
FIG. 1c, which is not necessarily required for functional reasons,
however, cf. FIGS. 1a and b.
[0036] In FIGS. 2a and b, a front view of different embodiments of
the second functionality element is seen. In all embodiments, the
completely closed and sufficiently small chambers (3) provided on
top of each other which are filled, for example, with catalytic,
adsorbing or biologically active material can be seen. The walls of
the chambers are fluid-permeable but impermeable to the packing
material. As shown in FIG. 2b, a plurality of chambers (3) can be
arranged in a horizontal layer and can be alternately displaced in
the next lower layer. It is also possible to provide only one
closed chamber in every horizontal layer, as in FIG. 2a. The
chambers (3) and conducting sections (6) together form a vertical
sheet layer (2).
[0037] FIGS. 3a and b show side views of a second functionality
element having closed chambers (3). The chambers are formed by
tightly joining the upper and lower sides of the lateral walls 4a
and 4b of the second functionality elements both at the edges (5)
and in the chamber interspaces (6), so that the chambers are
tightly closed with respect to the packing material. This joining
if effected, for example, by welding. It is useful to leave a
little free space between the second functionality elements and the
edges of the packing in order to facilitate flowing around the
second functionality elements.
[0038] FIGS. 4a and b show a perspective view of an element of the
structured multi-purpose packing. The arrangement of the different
functional parts in alternating layers can be seen. The material
separation elements (1) which exclusively serve the function of
material separation consist of structured fabric sheets or metal
sheets (7) with different profiles. It is advantageous if the
orientation of the channels of the fabric sheets changes
alternately. A wide variety of designs of structured fabric sheets
can be employed, the most suitable being selected to provide a
purposeful optimization with respect to the intended application of
the multi-purpose packing. At their points of contact (11), the
different functional units can be tightly joined, but this may also
be omitted in favor of a higher flexibility. A skirt (8) with
lobe-like protrusions (9), as usual with structured packings,
tightly encloses the functional elements and in addition stabilizes
the multi-purpose packing within the column.
[0039] The packing element shown is designated for a multi-purpose
column having a circular cross-section, but the realization of the
multi-purpose packing is basically possible for all
cross-sections.
[0040] FIGS. 5a and b show different embodiments of the
configuration of a second functionality element. Two preformed
fabric sheets (4a and 4b) are joined together. The generated
chambers (3) are filled prior to being closed. A complete filling
of the chambers is not necessary. The filling amount is also
variable to provide a purposeful optimization with respect to the
intended use.
[0041] FIG. 6 shows the structure of a reactor for the preparation
of tertiary alcohols in a reactive rectification using a structured
multi-purpose packing according to the invention. The feeding of
the tertiary olefin stream is effected through feed line (R1) below
the structured multi-purpose packing. The feeding of the water is
effected through feed line (R2) above the structured multi-purpose
packing. Thus, the tertiary olefin and the water flow in
counter-current through the structured multi-purpose packing (R3)
over the ion exchanger contained therein, filled in chambers. At
the head of the column, unreacted tertiary olefin is condensed in
an azeotrope with water (in the case of TAA preparation from 98% by
weight of isoamylene and 2% by weight of water) (R4) and
recirculated into the column together with fresh water above the
catalytic packing (R5). The tertiary alcohol prepared and excess
water go into the bottoms of the reactor; from there (R6) are
optionally through a side stream (R7), they are removed and, in the
case where a further purification is desired, fed to a distillation
column for azeotropic distillation.
EXAMPLES
Examples 1 and 2
[0042] Preparation of tertiary amyl alcohol (TAA)
[0043] The preparation of TAA is effected by reacting isoamylene
and water in a continuously operated reactive rectification in the
reactor shown in FIG. 6. The diameter of the column is 55 mm. The
diameter of the packing is 213 mm. The setting of the quantity
recycled is 25 kg/h at an infinite recycle ratio. The temperature
in the reactor is about 60.degree. C. at the level of the
multi-purpose packing and between 110 and 125.degree. C. in the
bottoms for a total pressure of 2.2 bar in the column.
[0044] The multifunctional packing Multipak.RTM. of Montz GmbH in
which the walls of the chambers of the second functionality
elements are made of steel serves as the structured multi-purpose
packing. This multi-purpose packing is filled with about 4 kg
(corresponding to 5.5 liters) of a styrene-divinylbenzene resin
containing acidic sulfur groups (commercial product Lewatit.RTM.
K2631 of Bayer AG).
[0045] An isoamylene stream obtained by the cleavage of tertiary
amyl methyl ether and having a purity of above 99% by weight of
isoamylene serves as the feed stream.
[0046] The remaining experimental conditions and the results of the
reactive rectification are shown in Table 1.
1 TABLE 1 B1 B2 B3 B4 isoamylene feed stream [g/h] 300 600 800 1200
water feed [g/h] 75 144 224 312 ratio of water/isoamylene in the
0.25 0.24 0.28 0.26 feed stream [g/g] TAA production [g/h] 293 604
668 887 TAA content in the bottoms [%] 81.4 87.7 69.5 55.6 TAA
conversion, based on 77.8 80.1 67.1 58.2 isoamylene feed stream
[%]
* * * * *