CA1234150A - Process for making acetic anhydride and, if desired, acetic acid - Google Patents

Process for making acetic anhydride and, if desired, acetic acid

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Publication number
CA1234150A
CA1234150A CA000486574A CA486574A CA1234150A CA 1234150 A CA1234150 A CA 1234150A CA 000486574 A CA000486574 A CA 000486574A CA 486574 A CA486574 A CA 486574A CA 1234150 A CA1234150 A CA 1234150A
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CA
Canada
Prior art keywords
compounds
iodide
acetic anhydride
acetic acid
methyl acetate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA000486574A
Other languages
French (fr)
Inventor
Heinz Erpenbach
Klaus Gehrmann
Peter Horstermann
Klaus Schmitz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hoechst AG
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Hoechst AG
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Filing date
Publication date
Application filed by Hoechst AG filed Critical Hoechst AG
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Publication of CA1234150A publication Critical patent/CA1234150A/en
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Classifications

    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/10Preparation of carboxylic acids or their salts, halides or anhydrides by reaction with carbon monoxide
    • C07C51/12Preparation of carboxylic acids or their salts, halides or anhydrides by reaction with carbon monoxide on an oxygen-containing group in organic compounds, e.g. alcohols
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/54Preparation of carboxylic acid anhydrides
    • C07C51/56Preparation of carboxylic acid anhydrides from organic acids, their salts, their esters or their halides, e.g. by carboxylation

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Abstract

PROCESS FOR MAKING ACETIC ANHYDRIDE AND, IF DESIRED, ACETIC ACID
ABSTRACT OF THE DISCLOSURE:
Acetic anhydride and acetic acid are made by reacting methyl acetate and/or dimethylether and, if desired, methanol with carbon monoxide, optionally in the presence of water, at temperatures of 350 to 575 K, under pressures of 1 to 300 bar in the presence of a catalyst system containing noble metals belonging to group VIII of the Periodic System of the ele-ments or their compounds, iodine and/or its compounds and, if desired, carbonyl-yielding non noble metals of groups IV, V, VI, VII or VIII of the Periodic system of the elements, or their compounds and, if desired, an aliphatic carboxylic acid having from 1 to 4 carbon atoms. To this end, a catalyst system containing tetrabutylphosphonium iodide as an additi-onal promoter is used.

Description

~3~

This invention relates to a process for making acetic an-hydride and, if desired, acetic acid by reacting methyl acetate and/or dimethylether and, if desired, methanol with carbon mon-oxide, optionally in the presence of water, at temperatures of 350 to 575 K, under pressures of 1 to 300 bar in the presence of a catalyst system containing noble metals belonging to group VIII of the Periodic System of the elements, or their compounds, iodine and/or its compounds and, if desired, carbonyl-yielding non noble metals of groups IV, V, VI, VII or VIII of the Perio-dic system of -the elements, or their compounds and, if desired, an aliphatic carboxylic acid having from 1 to 4 carbon atoms, which comprises using a catalyst system containing tetrabutyl-phosphonium iodide as an additional promoter.
German Specification DE 24 50 965 C2 describes a process for making acetic anhydride from methyl acetate and carbon mon-oxide, if desired in the presence of 5 - 50 vol. % hydrogen, under pressures of 1 to 500 bar and at temperatures of 50 to 250C in contact with catalysts containing noble metals belong-ing to group VIII of the Periodic system of the elements, or 20. their compounds and iodine and/or its compounds and optionally also carbonyl-yielding metals, e,g. Co, Ni or Fe. The iodine compounds mentioned include quaternary ammonium and phosphonium compounds, such as tetramethylammonium iodide and tetraethyl-phosphonium iodide. These two compounds are however not very useful for the catalyst system as they are liable to deposit due to their high melting points and minor solubility, and there-fore do not permit the catalyst solution to be cycled continuous-ly. Still further additional catalyst constituents include alkyl and aryl phosphines,such as tri-n-butylphosphine and triphenyl-3û phosphine.

~' s~
German Specification DE 26 10 036 C2 describes a comparableprocess for making monocarboxylic anhydrides, wherein however a metal belonging to groups IVa, Va or VIa of the Periodic System, preferably chromium, is used together with the noble metal of 5 group VIII of tha Periodic System, an iodide as well as an or-ganonitrogen or organophosphorus compound containing trivalent nitrogen or phosphorus.
The process described in German Specification DE 26 10 036 C2 is seriously handicapped by the fact that the metal compounds 10 and daughter products of the multiple promoter are ex-tensively insoluble in boiling acetic anhydride so that the circulation of the catalyst system invariably necessary for continuous opera-tion is rendered very difficult or even made impossible. In addition, these insoluble compounds have been found unduly to 15 affect the separation of acetic anhydride from the catalyst.
Indeed, on subjecting the reaction mixture to distillative work up, chromium salts commence de-positing on the evaporator, and -the transfer of heat is sensitively affected. As a result, it is necessary for the evaporator temperature to be increased natural-20 ly with considerable impairment of the catalyst system.
German Specification DE 29 39 839 A1 describes a processfor making acetic anhydride in the presence of a noble metal-containing catalyst system containing a quaternary organophos-phorus compound and a zirconium compound soluble in the reaction 25 mixture as additional constituents. The quaternary organophos-phorus compounds are adducts of organic phosphines and methyl iodide. The melting point, even of rather useful tributylmethyl-phosphine, is however as high as almost 140C. This fact makes it invariably necessary, in the interest of maintaining fusion, 30 for the catalyst solution to be separated at an equally high ~3~

temperature subjecting the catalyst system to considerable thermal stress. For these reasons it is not possible to reduce the temperature and separate the catalyst solution under milder conditions, e.g. under reduced pressure, as the step of reduc-ing the temperature involves the risk of sudden crystallization.The lnvention as described herein which provides for an outstanding catalyst activity, expressed in g acetic anhydride obtalned per g elemental noble metal per hour, permits these disadvantages to be set aside as the catalyst solution can be separated from the reaction product under conditions more favor-able than heretofore by the use of tetrabutylphosphonium iodide having a melting point o~ 103C. As has unexpectedly been found tetrabutylphosphonium iodide is reliably stable under the reac-tion conditions whereas corresponding quaternary phosphonium iodides having 5 carbon atoms and more undergo decomposition with formation of corresponding methyl-substituted phosphonium iodides. Quaternary phosphonium iodides having less than 4 car-bon atoms in the respective substituent should conveniently not be used because of their high melting points of 200C and more.
2û Further preferred and optional features of the present i.n-vention provide:
a) for the catalyst system noble me-tal(compound)/iodine(com-pound)/carbonyl-yielding non noble metal(compound)/carboxy-lic acid/tetrabutylphosphonium iodide to be used in an atomic or molar ratio oE 1:(1-1400):(0-10):(0-2000):
(1-12ûO);
b) for methyl acetate, methanol and water or dimethylether, methanol and water to be used in a molar ratio of 1:(0-S):
( O - 1 ) ;
c) for a carbon monoxide/hydrogen mixture containing up to :~3~
10 vol. % hydrogen to be used.
The process of this invention should preferably be effected at temperatures of 400 to 475 K under pressures of 20 to ~50 bar. 0.0001 to 0.01 mol noble metal of group VIII of the Perio-dic System of the elements, or its sompounds should preferablybe used per mol methyl acetate and/or dlmethylether. It is also advantageous to use the catalyst system noble metal(compound)/
iodine(compound)/carbonyl-yielding non noble metal(compound)/
carboxylic acid/tetrabutylphosphonium iodide in an atomic or 10 molar ratio of 1:(10-300):(0-8):(0-600):(10-300). The carboxy-lic acid if used, preferably is acetic acid.
All of the metals belonging to group VIII of the Periodic System of the elements (Ru, Rh, Pd, Os, Ir, Pt) can be used as Ihe catalyst. Rhodium however is most active. It and all other 15 metals should be used in form of compounds which are soluble : under the reaction conditions and form the active noble metal/
carbonyl-complex, e.g. RhCl3 . 3 H20, ! Rh(CO)~Cl 72~
/ Pd(C0)2I_72, IrCl3, Pd(CH3C02)2, PdC12, Pd(C5H702)2-Methyl iodide but also acetyl iodide or hydrogen iodide are 20 the compounds which should preferably be used as iodine compounds.
The non noble metals of groups IV, V, VI, VII and VIII, forming carbonyl complexes which may optionally be used as pro-moters should conveniently be used in form of readily soluble compounds, e.g. acetyl acetonate or carbonyl, in -the reaction.
25 Compounds of the metals Ti, Zr, V, Nb, Ta, Cr, ~o, W, Mn, Re, Fe, Co or Ni are preferably used.
The process of this invention can be effected continuously or discontinuously as more fully described in the following:
.. The mixture to undergo reaction is placed in an autoclave 30 of stainless steel (Hastelloy~B2) and reacted under the condi-~d~ Mark ~:34~

tions described. Unreacted carbon monoxide and hydrogen, if any,are cycled whereas a small partial stream thereof (off-gas) is allowed to escape from the system. Fresh carbon monoxide optio-nally admixed with hydrogen is metered into the cycle gas at 5 the same rate as it is consumed. Quantities oE fresh methyl acetate and/or dimethylether and me-thanol, if any, and/or water, corresponding to the conversion rate, are admitted to the reac-tor. Reaction mixture issues from the reactor at the same rate as feed materials are added. In a short-way evaporator, the reaction mixture is separated from the catalyst system which is recycled into the reactor. The low boilers (methyl acetate, di-methylether, methyl iodide) are separated in a first column and recycled to the reactor. The still product of the first column is worked up in two further columns to give acetic acid and . 15 acetic anhydride.
Example 1 250 9 methyl acetate, 1.6 9 RhC13 . 3H20, 60 9 methyl iodide and 70 9 tetrabutylphosphonium iodide were placed in a Hastelloy autoclave; next, a pressure of 25 bar was established by inject-ing C0. The whole was heated to the reaction temperature of 455K and a total pressure of 50 bar was established and maintained o.ver a period of 50 minutes by continuous injection of C0. After cooling with release of pressure, the reaction mixture was ana-lyzed gas-chromatographically and found to contain 276 9 acetic anhydride, corresponding to 1766 9 Ac20 per gram Rh per hour.
Example 2 200 9 dimethylether, 1.6 9 RhCl3 . 3H20, 7û 9 methyl iodide and 80 9 tetrabutylphosphoni.um iodide were reacted with carbon monoxide in the Hastelloy autoclave at 455 K under a pressure of 60 bar. After a reaction period of 15 minutes, the reac-tion mix-~L23~

ture was found to contain 228 9 acetic anhydride and 156 9 methyl acetate, corresponding to 1459 9 Ac20 per gram Rh per hour.
Example 3 300 9 methyl acetate, 1.6 9 RhC13 . 3H20, 90 9 methyl iodide, 70 9 acetic acid and 70 9 tetrabutylphosphonium iodide were react-ed with carbon monoxide in an autoclave at 453 K under a pressure of 50 bar. After a reaction period of 15 minutes, the reaction mixture was found to contain 298 9 ace-tic anhydride, correspond : ing to 1907 9 Ac20 per 9 Rh per hour.
Example 4 280 9 methyl acetate, 2 9 Pd(OAc)2, 70 9 methyl iodide and 100 9 tetrabutylphosphonium iodide were reacted with C0 in a Hastelloy autoclave at 460 K under a pressure of 50 bar. After 65 minutes, 203 9 acetic anhydride, corresponding to 193 9 Ac20 per 9 Pd per hour, was obtained.
Example 5 250 9 methyl acetate, 0.8 9 RhC13 . 3H20, 5 9 zirconium acetyl acetonate, 90 9 methyl iodide, 90 9 acetic acid and 120 9 tetrabutylphosphonium iodide were rPacted with C0 in a Hastelloy autoclave at 458 K under 70 bar. After a reaction period of 25 minutes, 282 9 acetic anhydride, corresponding to 2165 9 Ac20 per gram Rh per hour, was found to have been obtained.
Example 6 280 9 methyl acetate, 1.8 9 RhC13 . 3H20, 8 9 vanadium hexa-carbonyl, 90 9 methyl iodide and 70 9 tetrabutylphosphonium iodide were reacted with C0 in a Hastelloy autoclave at 460 K under 50 bar. After a reaction period of 15 minutes, 292 9 acetic anhydride, corresponding to 1661 9 Ac20 per 9 Rh per hour was found to have been obtained.
. 6 ~3~5~

Example 7 250 9 methyl acetate, 1.6 g RhCl3 . 3H20, 7 9 chromhexacar-bonyl, 80 9 methyl iodide and 75 9 tetrabutylphosphonium iodide were reacted with C0 in a Hastelloy autoclave at 450 K under 60 bar. After 14 minutes, 294 9 acetic anhydride, corresponding to 2016 9 Ac20 per gram Rh per hour, was obtained.
Example 8 250 9 methyl acetate, 1.6 9 RhCl3 . 3H20, lû 9 dirheniumde-cacarbonyl, 150 9 methyl iodide, 75 9 acetic acid and 100 9 te-trabutylphosphonium iodide were reacted with C0 in a Hastelloyautoclave at 453 K under 60 bar. After 15 minutes, the reaction mixture was found to contain 286 9 acetic anhydride, correspond-ing to 1830 gram Ac20 per gram Rh per hour.
Example 9 280 9 methyl acetate, 2 9 Pd(OAc)2, 10 9 dicobaltoctacar-bonyl, 60 9 methyl iodide and 100 9 tetrabutylphosphonium iodide were reacted with C0 in a Hastelloy autoclave at 450 K under 80 bar. After 25 minutes, the reaction mixture was ~ound to contain 248 9 acetic anhydride, corresponding to 628 9 Ac20 per gram Pd per hour.
Example 10 250 9 methyl acetate, 50 9 methanol, 1,6 9 RhCl3 . 3H20, 100 9 methyl iodide and 70 9 tetrabutylphosphonium iodide were reacted with C0 in a Hastelloy autoclave at 455 K under 50 bar.
25 After a reaction period of 15 minutes, 288 9 acetic anhydride and 94 9 acetic acid, corresponding to 1843 g Ac20 per gram Rh per hour and 601 9 acetic acid per gram Rh per hour, were obtained.
Example 11 200 9 dimethylether, 50 9 methanol, 1.6 9 RhC13 . 3H20, 5~

90 9 methyl iodide and 90 9 tetrabutylphosphonium iodide were reacted with C0 in a Hastelloy autoclave at 458 K under 60 bar.
After a reaction period of 15 minutes, 242 9 acetic anhydride, 146 9 methyl acetate and 94 9 acetic acid, corresponding to 1549 9 Ac20 per gram Rh per hour and 601 9 acetic acid per gram Rh per hour, were obtained.
Example 12 300 9 dimethylether, 1.8 9 RhCl3 . 3H20, lûO g methyl iodide, 100 9 acetic acid and 80 9 tetrabutylphosphonium iodide were reacted with a C0/H2-mixture containing 5 vol. % H2 in a Hastelloy autoclave at 458 K under 80 bar. After 15 minutes, 340 9 acetic anhydride was obtained together with 160 9 methyl acetate, 70 9 ethylidene diacetate and 30 9 additionally formed acetic acid, corresponding to 1935 9 Ac20 per gram Rh per hour and 171 9 acetic acid per gram Rh per hour.
Example 13 200 9 methyl acetate, 300 9 methanol, 1.6 9 RhCl3 . 3H20, 100 9 methyl iodide and 75 9 tetrabutylphosphonium iodide were reacted with C0 in a Hastelloy autoclave at 455 K under 50 bar.
20 After a reaction period of 18 minutes, 220 9 acetic anhydride and 208 9 acetic acid, corresponding to 1173 9 Ac20 per gram Rh per hour and 1109 g acetic acid per gram Rh per hour, were obtained.
Example 14 300 9 methyl acetate, 36 9 water, 70 9 hydrogen iodide, 1.6 9 RhCl3 . 3H20 and 80 9 tetrabutylphosphonium iodide were reacted with C0 in a Hastelloy autoclave at 458 K under 40 bar.
After a reaction period of 14 minutes, 122 9 acetic anhydride and 273 9 acetic acid, corresponding to 836 9 Ac2û per gram Rh 30 per hour and 1872 9 ace-tic acid per gram Rh per hour, were ob-tained.

Claims (4)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
WE CLAIM
1. A process for making acetic anhydride and, if desired, acetic acid by reacting methyl acetate and/or dimethyl-ether and, if desired, methanol with carbon monoxide, optionally in the presence of water, at temperatures of 350 to 575 K, under pressures of 1 to 300 bar in the pre-sence of a catalyst system containing noble metals be-longing to group VIII of the Periodic System of the ele-ments, or their compounds, iodine and/or its compounds and, if desired, carbonyl-yielding non noble metals of groups IV, V, VI, VII or VIII of the Periodic system of the elements, or their compounds and, if desired, an aliphatic carboxylic acid having from 1 to 4 carbon atoms, which comprises using a catalyst system contain-ing tetrabutylphosphonium iodide as an additional promoter.
2. A process as claimed in claim 1, wherein the catalyst system noble metal(compound)/iodine(compound)/carbonyl-yielding non noble metal (compound)/carboxylic acid/tetra-butylphosphonium iodide is used in the atomic or molar ratio of 1:(1-1400):(0-10):(0-2000):(1-1200).
3. A process as claimed in, claim 1, wherein methyl acetate, methanol and water or dimethylether, methanol and water are used in a molar ratio of 1:(0-5):(0-1).
4. A process as claimed in claim 1, wherein a carbon monoxide/
hydrogen-mixture containing up to 10 vol. % hydrogen is used.
CA000486574A 1984-08-08 1985-07-10 Process for making acetic anhydride and, if desired, acetic acid Expired CA1234150A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEP3429180.6 1984-08-08
DE3429180A DE3429180A1 (en) 1984-08-08 1984-08-08 METHOD FOR PRODUCING ACETIC ACID ANHYDRIDE AND GGF. ACETIC ACID

Publications (1)

Publication Number Publication Date
CA1234150A true CA1234150A (en) 1988-03-15

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CA000486574A Expired CA1234150A (en) 1984-08-08 1985-07-10 Process for making acetic anhydride and, if desired, acetic acid

Country Status (9)

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EP (1) EP0170964B1 (en)
JP (1) JPS6147441A (en)
AT (1) ATE39108T1 (en)
AU (1) AU577401B2 (en)
BR (1) BR8503723A (en)
CA (1) CA1234150A (en)
DE (2) DE3429180A1 (en)
MX (1) MX163195B (en)
ZA (1) ZA855952B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5380929A (en) * 1988-07-13 1995-01-10 Hoechst Aktiengesellschaft Process for the preparation of acetic acid and acetic anhydride
US5672743A (en) * 1993-09-10 1997-09-30 Bp Chemicals Limited Process for the production of acetic acid

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1248549A (en) * 1984-08-16 1989-01-10 Richard W. Wegman Production of anhydrous carboxylic acids from alcohols using rhodium complex catalysts and organic ester source
FR2592040B1 (en) * 1985-12-24 1988-07-15 Charbonnages Ste Chimique PROCESS FOR THE SYNTHESIS OF (METH) ACRYLIC ANHYDRIDES
DE4034867A1 (en) * 1990-11-02 1992-05-07 Hoechst Ag CONTINUOUS PROCESS FOR THE SIMULTANEOUS PRODUCTION OF ACETIC ACID AND ACETIC ACID ANHYDRIDE
FR2675796B1 (en) * 1991-04-25 1993-08-20 Lorraine Laminage PROCESS FOR THE PREPARATION OF ACETIC ANHYDRIDE FROM METHYL FORMIATE.
GB9112623D0 (en) * 1991-06-12 1991-07-31 Bp Chem Int Ltd Separation process
JP4343420B2 (en) * 2000-11-29 2009-10-14 三井化学株式会社 Polar group-containing branched olefin copolymer and thermoplastic resin composition containing the copolymer
CN1219800C (en) 2000-09-07 2005-09-21 三井化学株式会社 Olefine copolymer containing polar group, preparation method thereof, thermoplastic resin composition containing it and application thereof

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4270015A (en) * 1979-02-05 1981-05-26 Texaco Inc. Manufacture of ethylene from synthesis gas (D#75,673-C1)
DE2939839A1 (en) * 1979-10-02 1981-04-23 Hoechst Ag, 6000 Frankfurt METHOD FOR PRODUCING ACETIC ACID ANHYDRIDE
CA1226300A (en) * 1983-03-02 1987-09-01 Eit Drent Process for the preparation of carboxylic acids
DE3461177D1 (en) * 1983-07-26 1986-12-11 Shell Int Research Process for the preparation of acetic acid and/or methyl acetate
DE3429179A1 (en) * 1984-08-08 1986-02-20 Hoechst Ag, 6230 Frankfurt METHOD FOR THE SIMULTANEOUS PRODUCTION OF CARBONIC ACIDS AND CARBONIC ACID ANHYDRIDES AND IF ANY. CARBONIC ACID ESTERS
CA1248549A (en) * 1984-08-16 1989-01-10 Richard W. Wegman Production of anhydrous carboxylic acids from alcohols using rhodium complex catalysts and organic ester source

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5380929A (en) * 1988-07-13 1995-01-10 Hoechst Aktiengesellschaft Process for the preparation of acetic acid and acetic anhydride
US5672743A (en) * 1993-09-10 1997-09-30 Bp Chemicals Limited Process for the production of acetic acid
US5942460A (en) * 1993-09-10 1999-08-24 Bp Chemicals Limited Catalyst system

Also Published As

Publication number Publication date
ATE39108T1 (en) 1988-12-15
MX163195B (en) 1991-10-15
EP0170964B1 (en) 1988-12-07
DE3566662D1 (en) 1989-01-12
JPH0229060B2 (en) 1990-06-27
BR8503723A (en) 1986-05-13
DE3429180A1 (en) 1986-02-20
AU4588785A (en) 1986-02-13
EP0170964A2 (en) 1986-02-12
JPS6147441A (en) 1986-03-07
AU577401B2 (en) 1988-09-22
ZA855952B (en) 1986-04-30
EP0170964A3 (en) 1987-05-20

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