U.S. patent application number 09/878313 was filed with the patent office on 2002-02-21 for process for making butyraldehyde from butadiene.
Invention is credited to Gracey, Benjamin Patrick.
Application Number | 20020022749 09/878313 |
Document ID | / |
Family ID | 10844810 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020022749 |
Kind Code |
A1 |
Gracey, Benjamin Patrick |
February 21, 2002 |
Process for making butyraldehyde from butadiene
Abstract
Process for making butyraldehyde from an n-butenyl ester of a
carboxylic acid, wherein the n-butenyl ester is hydrolyzed to form
the corresponding n-butenyl alcohol n-butenyl alcohol so produced
is isomerized to form butyraldehyde.
Inventors: |
Gracey, Benjamin Patrick;
(Hull, GB) |
Correspondence
Address: |
NIXON & VANDERHYE P.C.
8th Floor
1100 North Glebe Road
Arlington
VA
22201
US
|
Family ID: |
10844810 |
Appl. No.: |
09/878313 |
Filed: |
June 12, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09878313 |
Jun 12, 2001 |
|
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PCT/GB99/04171 |
Dec 10, 1999 |
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Current U.S.
Class: |
568/484 ;
568/485 |
Current CPC
Class: |
C07C 45/512 20130101;
C07C 45/54 20130101; C07C 47/02 20130101; C07C 47/02 20130101; C07C
45/54 20130101; C07C 45/512 20130101 |
Class at
Publication: |
568/484 ;
568/485 |
International
Class: |
C07C 045/51 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 1998 |
GB |
9828338.5 |
Claims
I claim
1. A process for making butyraldehyde from an n-butenyl ester of a
carboxylic acid, said process comprising hydrolysing the n-butenyl
ester to form the corresponding n-butenyl alcohol and ii)
isomerising the n-butenyl alcohol produced in step i) to form
butyraldehyde.
2. A process as claimed in claim 1, wherein steps i) and ii) are
carried out simultaneously.
3. A process as claimed in claim 1, wherein said steps i) and ii)
are carried out simultaneously using a transition metal catalyst in
the presence of an acid or base.
4. A process as claimed in claim 1, wherein the transition metal
catalyst contains at least one of copper, vanadium, chromium,
molybdenum, tungsten, manganese, rhenium, iron, cobalt, nickel,
ruthenium, rhodium, palladium, platinum, osmium and iridium.
5. A process as claimed in claim 1, wherein said steps i) and ii)
are carried out simultaneously using a transition metal catalyst in
the presence of an acid selected from the group consisting of:
sulphonic acid, sulphuric acid, halogen acid, HY zeolite,
lanthanide triflate and triflic acid.
6. A process as claimed in claim 1, wherein steps i) and ii) are
carried out simultaneously in the liquid phase, in the presence of
an aromatic hydrocarbon solvent.
7. A process as claimed in claim 1, wherein step i) is carried out
before step ii).
8. A process as claimed in claim 7, wherein the step i) is carried
out in the presence of an acid or a base, and step ii) is carried
out in the presence of a transition metal catalyst.
9. A process as claimed in claim 7, wherein step i) is carried out
in the presence of an acid selected from the group consisting of:
sulphonic acid, sulphuric acid, halogen acid, HY zeolite,
lanthanide triflate and triflic acid, and step ii) is carried out
in the presence of a transition metal catalyst containing at least
one of copper, vanadium, chromium, molybdenum, tungsten, manganese,
rhenium, iron, cobalt, nickel, ruthenium, rhodium, palladium,
platinum, osmium and/or iridium.
10. A process as claimed in claim 7, wherein step i) carried out in
the liquid phase, in the presence of an aromatic hydrocarbon
solvent.
11. A process as claimed in claim 1, wherein the n-butenyl ester is
produced by reacting butadiene and a carboxylic acid to produce a
mixture of sec-butenyl ester and n-butenyl ester.
12. A process as claimed in claim 11, wherein the butadiene is
reacted with the carboxylic acid in the presence of a heterogeneous
catalyst selected from the group consisting of: Amberlyst 15.RTM.,
Amberlite IR120.RTM., Nafion.RTM., phosphoric acid functionalised
polymers, supported heteropolyacids and HY zeolites.
13. A process as claimed in claim 11, wherein butadiene is reacted
with the carboxylic acid in the presence of a homogeneous catalyst
selected from the group consisting of sulphonic acids,
heteropolyacids, triflic acid and triflate salts.
14. A process as claimed in claim 11, wherein the butadiene
employed is in the form of a hydrocarbon stream comprising
butadiene.
15. A process as claimed in claim 11, wherein the carboxylic acid
is an aliphatic mono-carboxylic acid.
16. A process as claimed in claim 11, wherein the sec-butenyl ester
produced by the reaction between the butadiene and the carboxylic
acid is converted into methyl ethyl ketone by hydrolysing the
sec-butenyl ester to form the corresponding but-1-en-3 -ol and ii)
isomerising the but-1-en-3 -ol produced to form methyl ethyl
ketone.
17. A process as claimed in claim 11, wherein the sec-butenyl ester
is recycled directly back to the butadiene/carboxylic acid
reaction, or converted back into butadiene and carboxylic acid in a
separate reaction step.
Description
A PROCESS FOR MAKING BUTYRALDEHYDE FROM BUTADIENE
[0001] The present invention relates to a process for making
butyraldehyde by hydrolysing an n-butenyl ester to form the
corresponding n-butenyl alcohol and isomerising the latter to form
butyraldehyde.
[0002] It is known that butyraldehyde can be produced by a number
of routes. For instance, U.S. Pat. No. 5,705.707 discloses a method
of making n-butyraldehyde and/or n-butanol by reacting butadiene
with an alcohol in the presence of an acidic catalyst. The reaction
produces a mixture of isomeric adducts, 1-alkoxybutene-2 (a) (also
known as crotyl ether) and 3-alkoxybutene-1 (b):
CH.sub.3.CH.dbd.CH.CH.sub.2.OR (a)
CH.sub.2.dbd.CHCH(OR).CH.sub.3 (b)
[0003] Compound (b) can be isomerised into compound (a). Compound
(a) is isomerised in the presence of a homogeneous or heterogeneous
transition metal catalyst to form the enol ether of the formula
(c):
CH.sub.3CH.sub.2CH.dbd.CHOR (c)
[0004] Ether (c) reacts with water to liberate butyraldehyde. This
hydrolysis reaction is catalysed by acids and bases. The
butyraldehyde product can be hydrogenated with suitable homogeneous
or heterogeneous catalysts to yield n-butanol. Thus compound (c) in
the presence of water and hydrogen and a homogeneous or
heterogeneous catalyst produces butanol and the parent alcohol ROH.
The parent alcohol can then be recycled to the addition reaction
stage.
[0005] A similar isomerisation hydrolysis reaction has been
repeated with amines in DE-A-4431528. This document describes a
process for the production of butyraldehyde which comprises the
addition of an amine to a butadiene. The reaction produces a
mixture of isomers, CH.sub.3CH.dbd.CHCH.sub.2NR.sub.2 and
CH.sub.3CH(NR.sub.2)CH.dbd.CH.sub.2- . The
CH.sub.3CH(NR.sub.2)CH.dbd.CH.sub.2 isomer is recycled back to the
addition reaction, whilst the CH.sub.3CH.dbd.CHCH.sub.2NR.sub.2
isomer is converted to the corresponding enamine,
CH.sub.3CH.sub.2CH.dbd.CHNR.sub.2- . This enamine is hydrolysed to
produce butyraldehyde for possible further processing and also
liberates the initial amine for re-use. The butyraldehyde may be
hydrogenated to the corresponding alcohol, if desired. The process
of DE-A4431528 is summarised in the diagram below: 1
[0006] The selectivity of the above processes has been found to be
limited by the formation of by-products. Such by-products include
C8 and higher species formed, for example, by dimerisation and
oligomerisation reactions of C4 species. In the process of
DE-A-4431528 , by-products may also be produced by amine catalysed
aldol condensation reactions of butyraldehyde.
[0007] We have now found that the selectivity of the butyraldehyde
production process can be increased by forming butyraldehyde from a
butenyl ester.
[0008] Accordingly, the present invention provides a process for
making butyraldehyde from an n-butenyl ester of a carboxylic acid,
said process comprising i) hydrolysing the n-butenyl ester to form
the corresponding n-butenyl alcohol and ii) isomerising the
n-butenyl alcohol produced in step i) to form butyraldehyde.
[0009] By "isomerising" is meant performing any process which
results in the direct or indirect conversion of the n-butenyl
alcohol to butyraldehyde.
[0010] Steps i) and ii) may be carried out simultaneously or
sequentially. Whilst carrying out steps i) and ii) simultaneously
may allow the process to be operated more economically, the
sequential hydrolysis and isomerisation stages may increase the
selectivity of the overall process.
[0011] Step i) may also be carried out before step ii). Thus, in
one embodiment of the present invention, n-butenyl ester is first
hydrolysed to form n-butenyl alcohol, which is conveniently
separable from the hydrolysis mixture as an azeotrope. The
separated n-butenyl alcohol is then isomerised into the
butyraldehyde product.
[0012] Preferably, the n-butenyl ester is an n-butenyl ester of a
saturated, aliphatic carboxylic acid.
[0013] In the present process, the n-butenyl ester (also known as
"crotyl ester") may not be readily available commercially. Instead
it may be produced by reacting butadiene with a saturated,
aliphatic carboxylic acid. As butadiene is a relatively inexpensive
by-product of the refining process, it provides a convenient
feedstock for making butyl esters. Thus, a preferred embodiment of
the present invention provides a process for the production of
butyraldehyde which comprises:
[0014] a) the addition reaction of butadiene to a carboxylic acid
to produce a mixture of sec-butenyl ester and n-butenyl ester;
and
[0015] b) (i) hydrolysing the n-butenyl ester formed in step a) to
form the corresponding n-butenyl alcohol, and (ii) isomerising of
the n-butenyl alcohol produced in step bi) to form
butyraldehyde.
[0016] Steps (i) and (ii) may be carried out simultaneously or
sequentially.
[0017] The diagram below summarises the reactions which may take
place in this preferred embodiment of the invention. 2
[0018] In step a), butadiene is reacted with a carboxylic acid
R'CO.sub.2H in the presence of an addition catalyst, catalyst 1.
Catalyst 1 may be a homogeneous or heterogeneous catalyst.
Heterogeneous catalysts may be advantageous in certain situations
as they facilitate separation of, for example, reaction products
from the reaction mixture. They may also allow the catalyst to be
conveniently separated from reaction by-products (which typically
comprise high boiling point butadiene oligomeric species). The
preferred catalysts are based on strong acid ion-exchange resins,
such as Amberlyst 15.RTM. and Amberlite IR120.RTM.. Other suitable
examples of heterogeneous catalysts include fluorinated
ion-exchange resins such as Nafion.RTM., phosphoric acid
functionalised polymers, and acidic oxides, for example, HY
zeolites.
[0019] A proportion of the acidic sites of such ion-exchange
catalysts may be exchanged with bulky counterions, such as alkyl
pyridinium, quaternary alkyl ammonium, quaternary arsonium and
quaternary phosphonium. These counterions exchange with some of the
acid sites on the support and can be added to the catalysts as
salts, such as halides, sulphates or carboxylates.
[0020] The heterogeneous catalyst phase may be a partially or fully
insoluble liquid phase. Such catalysts may take the form of acidic
ionic liquids, liquid acidic polymers and partially solvated
polymers. The catalyst may also be a solid phase, for example, I)
an HY zeolite, II) a strong acid macroreticular, macronet or gel
ion-exchange resin, or III) a heteropolyacid of tungsten or
molybdenum, which has been ion-exchanged and/or supported on a
carrier material.
[0021] In certain circumstances, the activity of heterogeneous
catalysts may decrease considerably after prolonged periods of use.
In such cases, it may be advantageous to carry out the process of
the present invention in a homogeneous phase. Suitable homogeneous
catalysts include sulphonic acids, heteropolyacids, triflic acid
(i.e. trifluoromethane sulphonic acid) and triflate salts. Suitable
heteropolyacids include Keggin structure heteropolyacids based on
tungsten, and strong acid ionic liquids such as those described in
prior published EP-A-693088, WO-A-95/21872 and EP-A-558187.
Suitable organic sulphonic acids include methane sulphonic acid,
p-toluenesulphonic acid and sulphonated calixarenes. Examples of
triflate salts include lanthanide triflates, such as lanthanum
trifluoromethanesulphonic acid salts.
[0022] The presence of water as a reaction adjuvant can also
beneficially affect the activity and selectivity of the catalysts.
It has been found that moderately low levels of water are required:
at levels above 5% w/w the catalyst activity is significantly
reduced, whereas at levels below 0.05% w/w, the activity though
high is rapidly lost due to deactivation of the catalyst.
Consequently the water level in the reaction zone is suitably in
the range from 0.05 to 5 % w/w on the carboxylic acid, preferably
from 0.05 to 1% w/w.
[0023] The butadiene feedstock may be employed either as a purified
chemical, or in the form of a hydrocarbon stream comprising
butadiene. Such hydrocarbon streams include refinery streams such
as mixed C4 streams containing butadiene, as well as other C4
species such as butane, 1-butene, 2-butene, isobutane, and
isobutene. The addition reaction (step (a)) can be used to remove
butadiene from such hydrocarbon streams, thereby avoiding the need
to remove butadiene in a separate processing stage.
[0024] The butadiene employed may be dissolved in the reaction
mixture, or introduced into the reactor as a gaseous reactant. In
certain embodiments, the reaction is carried out in multi-phase,
with butadiene being present in the liquid reaction mixture, and as
a gaseous phase.
[0025] The carboxylic acid (RCO.sub.2H) feedstock suitably
comprises any saturated carboxylic acid feedstock, Dicarboxylic
acids such as succinic acid may be employed, although
mono-carboxylic acids, and in particular, aliphatic mono-carboxylic
acids are generally preferred. Suitable mono-carboxylic acids
comprise 1-6 carbon atoms. Preferably, the acid is acetic acid.
[0026] The relative mole ratios of butadiene to the carboxylic acid
reactant in the addition reaction is suitably in the range from 5:1
to 1:50, preferably in the range from 1:1 to 1:10.
[0027] This addition reaction is suitably carried out at a
temperature in the range from 20 to 150.degree. C., preferably from
40 to 90.degree. C. The reaction is suitably carried out at the
autogeneous reaction pressure which is determined by factors such
as the reaction temperature, presence of absence of solvent, excess
of reactants and impurities present in the butadiene stream. An
additional pressure may be applied to the system if the reaction is
carried out in a single phase, for example, if substantially all
the butadiene present is present in the liquid phase in the
reaction mixture.
[0028] It may also be advantageous to use polymerisation inhibitors
such as eg alkylated phenols such as 2,6-di-tert-butyl-p-cresol
(also known as "BHT" or butylated hydroxytoluene). Other related
compounds include the Irganox.RTM. series of materials (ex Ciba
Gigy), the Lowinox.RTM. series of materials (ex Great Lakes
Chemical Corporation); the Tropanol.RTM. series (ex ICI),
t-butylcatechol, nitroxides such as di-tert-butylnitroxide,
N,N-dimethyl4-nitrosoaniline, nitric oxide, and stable radicals,
such as 2,2,6,6-tetramethyl-piperidine-1-oxyl,
2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl and
2,2,6,6-tetramethylpyrrolidine-1-oxyl.
[0029] The reaction between butadiene and the carboxylic acid
produces a mixture of butenyl esters: n-butenyl ester and
sec-butenyl ester. The n-butenyl ester is converted into the
butyraldehyde end-product by hydrolysis isomerisation (step (b)).
The sec-butenyl ester, on the other hand, may be removed, for
example, for use, sale or further reaction. An example of such a
further reaction is the conversion of sec-butenyl ester into methyl
ethyl ketone and carboxylic acid. Such a conversion step may be
carried out by subjecting the ester to simultaneous or sequential
stages of hydrolysis and isomerisation. As with the n-butenyl
isomer, simultaneous hydrolysis and isomerisation may allow the
process to be operated more economically. However, sequential
hydrolysis and isomerisation stages may increase the selectivity of
the overall process.
[0030] Where the hydrolysis and isomerisation steps are carried out
sequentially, it is preferable for the sec-butenyl ester to be
hydrolysed before it is isomerised. This is because the conversion
of the allylic ester to its vinyl isomer has been found to be
thermodynamically unfavorable. Thus, in one embodiment of the
present invention, sec-butenyl ester is first hydrolysed to form
but-1-en-3-ol, which is conveniently separable from the hydrolysis
mixture as an azeotrope. The separated alcohol is then isomerised
into the ketone product.
[0031] Instead of (or in addition to) converting the sec-butenyl
ester into methyl ethyl ketone, the sec-butenyl ester may also be
recycled back to the addition reaction (step (a)). Under the
reaction conditions, sec-butenyl interconverts with butadiene, free
carboxylic acid and the n-butenyl ester. Rather than recycling the
sec-butenyl ester to the addition reaction directly, however, it is
also possible to convert the sec-butenyl ester back into butadiene
and carboxylic acid separately. The conversion of the sec-butenyl
ester to free carboxylic acid and butadiene can be achieved by
treatment in the vapour phase with an acidic support. Suitable
supports include silica-aluminas. The butadiene and carboxylic acid
produced may then be returned to the addition reactor. This may
have a beneficial effect on productivity and selectivity.
Alternatively, at least one of the butadiene and carboxylic acid
may be sold, or used for further reaction.
[0032] The addition reaction may be carried out in a plug flow
reactor, with the unused butadiene being flashed off and recycled
to the reactor via a vapour liquid separator. Some of the butadiene
may be present as a separate gas phase, whilst the remainder of the
butadiene is dissolved in the reaction mixture. This results in
either a trickle bed or bubble bed operation. A typical LHSV
(liquid hourly space velocity=volume of liquid feed/catalyst bed
volume) for the carboxylic acid is 0.5 to 20 more preferably 1 to
5.
[0033] The addition reactor may alternatively be carried out in a
slurry reactor. In such a reactor, the deactivated catalyst may be
continuously removed from the reactor as a bleed stream. It is
economically advantageous to run with catalyst in various stages of
deactivation to improve the utilisation of catalyst. In this case,
the total loading of catalyst (activated+deactivated) can reach
high levels such as 50% w/w of the reaction charge.
[0034] The butadiene may be added gradually to the carboxylic acid,
for example, by multiple injection at constant pressure. This may
be carried out in a batch reactor. By adding the butadiene
gradually in this manner, side reactions leading to, for example,
the polymerisation of the butadiene may be minimised.
[0035] The products produced by the addition reaction may be
separated from the reactants by distillation. A small amount of
water azeotroping of reaction products may occur due to the low
levels of water employed. However, this is minor and does not
significantly effect the separation of the isomeric butenyl esters,
i.e. the n-butenyl ester and secondary butenyl ester.
[0036] The n-butenyl ester produced in the addition step is
converted to butyraldehyde in step b). This is achieved by i)
hydrolysis and ii) isomerisation. Where steps i) and ii) are
carried out simultaneously, a transition metal catalyst may be used
in the presence of an acid or base to perform the purpose of
catalysts 2 and 3 (see diagram). Preferred transition metal
complexes are those containing elements from Group Ib, Vb, VIb,
VIIb and VIIIb of the Periodic Table of Elements on pages 448 and
449 of the Handbook of Physics & Chemistry (.sub.44.sup.th
Edition) published by the Chemical Rubber Publishing Company, Ohio
USA (Reprint, April 1962), particularly copper, vanadium, chromium,
molybdenum, tungsten, manganese, rhenium, iron, cobalt, nickel,
ruthenium, rhodium, palladium, platinum, osmium and/or iridium.
Preferably, a transition metal catalyst supported on an acidic
residue is employed. Examples of suitable acidic residues include
strongly acidic ion-exchange resins and sulphonic acids such as
para-toluene sulphonic acid. Mineral acids such as sulphuric acid
and halogen acids; acidic oxides such as HY zeolite; Lewis acids
such as lanthanide triflates; and organic acids such as triflic
acid may also be suitable. One advantage of carrying out the
hydrolysis and isomerisation steps simultaneously is that it
minimises the total number of process stages required for the
production of the final product. The butyraldehyde produced may be
recovered from the reaction mixture by distillation, preferably,
whilst the hydrolysis/isomerisation reaction is in process.
[0037] The simultaneous hydrolysis and isomerisation step may be
carried out in the liquid phase, optionally, in the presence of a
solvent such as an aromatic hydrocarbon solvent. Suitable solvents
include toluene and ethers, such as methyl tertiary butyl ether and
tetrahydrofuran. The reaction may be carried out at a temperature
of from 25 to 250.degree. C., preferably, from 50 to 150.degree. C.
and more preferably, from 80 to 120.degree. C.
[0038] When the hydrolysis and isomerisation steps are carried out
sequentially, the hydrolysis step may be carried out in the
presence of an acid or a base, such as a Bronsted acid or base
(catalyst 2). Suitable isomerisation catalysts (catalyst 3) include
transition metal complexes. Preferred transition metal complexes
are those containing elements from Group Ib, Vb, VIb, VIIb and
VIIIb of the Periodic Table of Elements on pages 448 and 449 of the
Handbook of Physics & Chemistry (44.sup.th Edition) published
by the Chemical Rubber Publishing Company, Ohio USA (Reprint, April
1962), particularly copper, vanadium, chromium, molybdenum,
tungsten, manganese, rhenium, iron, cobalt, nickel, ruthenium,
rhodium, palladium, platinum, osmium and/or iridium.
[0039] The n-butenyl ester, upon hydrolysis, will produce an
equilibrium mixture of n-butenyl (i.e. crotyl) alcohol and the
carboxylic acid. In order to force the equilibrium in the desired
direction it may be necessary to remove the carboxylic acid, or
alcohol from the equilibrium mixture. This may be achieved by
removing the alcohol as an azeotrope.
[0040] The hydrolysis step may be carried out in the liquid phase,
optionally, in the presence of a solvent such as an aromatic
hydrocarbon solvent. Suitable solvents include toluene and ethers,
such as methyl tertiary butyl ether and tetrahydrofuran. The
reaction may be carried out at a temperature of from 25 to
250.degree. C., preferably, from 50 to 150.degree. C. and more
preferably, from 80 to 120.degree. C. The crotyl alcohol formed as
a result of this hydrolysis step may be recovered by distillation
or by phase separation into a suitable solvent. This crotyl alcohol
is then isomerised in a separate stage to give butyraldehyde.
[0041] The present invention is further illustrated, by way of
example, with reference to the following examples:
EXAMPLES
The Preparation of Butyraldehyde from Crotyl Acetate
[0042] The following chemicals were used in the preparation:
[0043] Crotyl acetate: 91 g (100 ml, 0.79 mol)
[0044] RuCl.sub.3:1 g (0.005 mol)
[0045] NaOH:2.1 g (0.05 mol)
[0046] de-ionised water
[0047] Under a steady flow of nitrogen as inert gas, crotyl acetate
(91.0 g, 100 ml, 0.79 mol) and 100 ml of an aqueous solution of
RuCl.sub.3 (1 g, 0.005 mol in 50 ml deinonised water) were mixed in
a three-necked round-bottomed flask equipped with a 15 plate
Oldershaw separation column to which a liquid reflux splitter was
fitted. A pressure equalising dropping funnel was also connected to
the reaction flask. The reaction mixture was stirred and heated to
ca. 90.degree. C. and a dropping funnel was used to slowly add
aqueous sodium hydroxide solution (2.1 g, 0.05 mol in 100 ml
de-ionised water) over a period of 2-3 hours. The temperature at
the top of the separation column was constantly monitored and the
first distillation fraction of a water/butyraldehyde was collected
between 68-72.degree. C. and an additional fraction between
80-82.degree. C. (water/crotyl aclohol). The first fraction
contained the major amount of the butyraldehyde product (as
determined by GC analysis) and was worked up by separating the
water layer from an organic layer comprising butyraldehyde in a
separating funnel. The second fraction mainly contained crotyl
alcohol. Subsequently, the organic layer containing the desired
butyraldehyde product was dried over magnesium sulphate overnight
and butyraldehyde was obtained with an estimated yield of 80% (46.8
g, 58.5 ml, 0.632 mol).
* * * * *