CA2053828C - Continuous process for the simultaneous preparation of acetic acid and acetic anhydride - Google Patents
Continuous process for the simultaneous preparation of acetic acid and acetic anhydride Download PDFInfo
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- CA2053828C CA2053828C CA002053828A CA2053828A CA2053828C CA 2053828 C CA2053828 C CA 2053828C CA 002053828 A CA002053828 A CA 002053828A CA 2053828 A CA2053828 A CA 2053828A CA 2053828 C CA2053828 C CA 2053828C
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- iodide
- catalyst
- nickel
- promoter
- acetic acid
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- WFDIJRYMOXRFFG-UHFFFAOYSA-N acetic acid anhydride Natural products CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 title claims abstract description 74
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 title claims abstract description 49
- 238000002360 preparation method Methods 0.000 title claims abstract description 12
- 238000010924 continuous production Methods 0.000 title claims abstract description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 36
- 238000006243 chemical reaction Methods 0.000 claims abstract description 21
- 239000003054 catalyst Substances 0.000 claims abstract description 19
- 238000000034 method Methods 0.000 claims abstract description 19
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 15
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 claims abstract description 13
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 claims abstract description 13
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 claims abstract description 11
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 9
- 239000010948 rhodium Substances 0.000 claims abstract description 9
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000003426 co-catalyst Substances 0.000 claims abstract description 8
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910002091 carbon monoxide Inorganic materials 0.000 claims abstract description 7
- INQOMBQAUSQDDS-UHFFFAOYSA-N iodomethane Chemical compound IC INQOMBQAUSQDDS-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000000203 mixture Substances 0.000 claims abstract description 7
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 7
- 150000002816 nickel compounds Chemical class 0.000 claims abstract description 5
- 150000002504 iridium compounds Chemical class 0.000 claims abstract description 4
- 229910001516 alkali metal iodide Inorganic materials 0.000 claims abstract description 3
- 229940107816 ammonium iodide Drugs 0.000 claims abstract description 3
- LSMAIBOZUPTNBR-UHFFFAOYSA-N phosphanium;iodide Chemical group [PH4+].[I-] LSMAIBOZUPTNBR-UHFFFAOYSA-N 0.000 claims abstract description 3
- 125000001453 quaternary ammonium group Chemical group 0.000 claims abstract description 3
- 239000000047 product Substances 0.000 description 11
- 150000001875 compounds Chemical class 0.000 description 6
- 238000009835 boiling Methods 0.000 description 5
- 230000006315 carbonylation Effects 0.000 description 5
- 238000005810 carbonylation reaction Methods 0.000 description 5
- XBDQKXXYIPTUBI-UHFFFAOYSA-N dimethylselenoniopropionate Natural products CCC(O)=O XBDQKXXYIPTUBI-UHFFFAOYSA-N 0.000 description 4
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 150000008064 anhydrides Chemical class 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- BFSQJYRFLQUZKX-UHFFFAOYSA-L nickel(ii) iodide Chemical compound I[Ni]I BFSQJYRFLQUZKX-UHFFFAOYSA-L 0.000 description 2
- 235000019260 propionic acid Nutrition 0.000 description 2
- IUVKMZGDUIUOCP-BTNSXGMBSA-N quinbolone Chemical compound O([C@H]1CC[C@H]2[C@H]3[C@@H]([C@]4(C=CC(=O)C=C4CC3)C)CC[C@@]21C)C1=CCCC1 IUVKMZGDUIUOCP-BTNSXGMBSA-N 0.000 description 2
- YHUKQLJMHYAHOI-UHFFFAOYSA-M 1,1-dimethylimidazol-1-ium;iodide Chemical compound [I-].C[N+]1(C)C=CN=C1 YHUKQLJMHYAHOI-UHFFFAOYSA-M 0.000 description 1
- BVUPLMFUPRCOEH-UHFFFAOYSA-M 1,3-dimethylpyridin-1-ium;iodide Chemical compound [I-].CC1=CC=C[N+](C)=C1 BVUPLMFUPRCOEH-UHFFFAOYSA-M 0.000 description 1
- HLNJFEXZDGURGZ-UHFFFAOYSA-M 1-methylpyridin-1-ium;iodide Chemical compound [I-].C[N+]1=CC=CC=C1 HLNJFEXZDGURGZ-UHFFFAOYSA-M 0.000 description 1
- RTQPKEOYPPMVGQ-UHFFFAOYSA-N 1-methylquinolin-1-ium Chemical compound C1=CC=C2[N+](C)=CC=CC2=C1 RTQPKEOYPPMVGQ-UHFFFAOYSA-N 0.000 description 1
- GOKCJCODOLGYQD-UHFFFAOYSA-N 4,6-dichloro-2-imidazol-1-ylpyrimidine Chemical compound ClC1=CC(Cl)=NC(N2C=NC=C2)=N1 GOKCJCODOLGYQD-UHFFFAOYSA-N 0.000 description 1
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 1
- MBZXSJWDBIIBLL-GDVGLLTNSA-N Homoisoleucine Chemical compound CCC(C)C[C@H](N)C(O)=O MBZXSJWDBIIBLL-GDVGLLTNSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910021586 Nickel(II) chloride Inorganic materials 0.000 description 1
- 229910021604 Rhodium(III) chloride Inorganic materials 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- MQRWBMAEBQOWAF-UHFFFAOYSA-N acetic acid;nickel Chemical compound [Ni].CC(O)=O.CC(O)=O MQRWBMAEBQOWAF-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 1
- 229920002301 cellulose acetate Polymers 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- KQWGXHWJMSMDJJ-UHFFFAOYSA-N cyclohexyl isocyanate Chemical compound O=C=NC1CCCCC1 KQWGXHWJMSMDJJ-UHFFFAOYSA-N 0.000 description 1
- YEGFGVXAUOBDQQ-UHFFFAOYSA-M dibutyl(dimethyl)phosphanium;iodide Chemical compound [I-].CCCC[P+](C)(C)CCCC YEGFGVXAUOBDQQ-UHFFFAOYSA-M 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- -1 for example Chemical class 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000000543 intermediate Substances 0.000 description 1
- 150000004694 iodide salts Chemical class 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000012263 liquid product Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- JNMIXMFEVJHFNY-UHFFFAOYSA-M methyl(triphenyl)phosphanium;iodide Chemical compound [I-].C=1C=CC=CC=1[P+](C=1C=CC=CC=1)(C)C1=CC=CC=C1 JNMIXMFEVJHFNY-UHFFFAOYSA-M 0.000 description 1
- 150000002815 nickel Chemical class 0.000 description 1
- 229940078494 nickel acetate Drugs 0.000 description 1
- QMMRZOWCJAIUJA-UHFFFAOYSA-L nickel dichloride Chemical compound Cl[Ni]Cl QMMRZOWCJAIUJA-UHFFFAOYSA-L 0.000 description 1
- BMGNSKKZFQMGDH-FDGPNNRMSA-L nickel(2+);(z)-4-oxopent-2-en-2-olate Chemical compound [Ni+2].C\C([O-])=C\C(C)=O.C\C([O-])=C\C(C)=O BMGNSKKZFQMGDH-FDGPNNRMSA-L 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- WYVAMUWZEOHJOQ-UHFFFAOYSA-N propionic anhydride Chemical compound CCC(=O)OC(=O)CC WYVAMUWZEOHJOQ-UHFFFAOYSA-N 0.000 description 1
- SONJTKJMTWTJCT-UHFFFAOYSA-K rhodium(iii) chloride Chemical compound [Cl-].[Cl-].[Cl-].[Rh+3] SONJTKJMTWTJCT-UHFFFAOYSA-K 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000010517 secondary reaction Methods 0.000 description 1
- FVAUCKIRQBBSSJ-UHFFFAOYSA-M sodium iodide Chemical compound [Na+].[I-] FVAUCKIRQBBSSJ-UHFFFAOYSA-M 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- CCIYPTIBRAUPLQ-UHFFFAOYSA-M tetrabutylphosphanium;iodide Chemical compound [I-].CCCC[P+](CCCC)(CCCC)CCCC CCIYPTIBRAUPLQ-UHFFFAOYSA-M 0.000 description 1
- RLZMYANQLOCZOB-UHFFFAOYSA-M tributyl(methyl)phosphanium;iodide Chemical compound [I-].CCCC[P+](C)(CCCC)CCCC RLZMYANQLOCZOB-UHFFFAOYSA-M 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/10—Preparation of carboxylic acids or their salts, halides or anhydrides by reaction with carbon monoxide
- C07C51/12—Preparation 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
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C53/00—Saturated compounds having only one carboxyl group bound to an acyclic carbon atom or hydrogen
- C07C53/08—Acetic acid
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/54—Preparation of carboxylic acid anhydrides
- C07C51/56—Preparation of carboxylic acid anhydrides from organic acids, their salts, their esters or their halides, e.g. by carboxylation
Landscapes
- 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
A continuous process is indicated for the simultaneous preparation of acetic acid and acetic anhydride from a starting mixture of methanol and methyl acetate and also, optionally, dimethyl ether, by reaction with carbon monoxide under anhydrous conditions at temperatures of 150 to 250°C and under elevated pressure in a reaction zone on a dissolved catalyst system containing a nickel compound, methyl iodide as promoter, at least one co-promoter, such as an alkali metal iodide, quaternary phosphonium iodide or quaternary ammonium iodide, and a co-catalyst, which process comprises using, as co-catalyst, a rhodium or iridium compound in a molar ratio of nickel: co-catalyst of la (0.005 to 0.1), adjusting the nickel concentration in the reaction zone to 0.01 to 0.1, preferably to 0.015 to 0.06 mol/l, and operating under an elevated pressure of 30 to 100 bar.
Description
2p~3~~~
The invention relates to a continuous process for the simultaneous preparation of acetic acid and acetic anhydride by reaction of mixtures of methanol and methyl acetate and also, optionally, dimethyl ether with carbon monoxide.
Acetic acid and acetic anhydride are intermediates for the vinyl acetate and cellulose acetate products Which to an increasing extent are being prepared industrially.
DE-3 823 645 C1 discloses a process for the simultaneous preparation of acetic acid and acetic anhydride by a carbonylation of methanol and methyl acetate in 'the presence of a catalyst system which contains carbonyl complexes of noble metals of group VIII of the periodic system of the elements. Rhodium in particular is a catalyst constituent of outstanding activity. The rhodium concentration in the reaction solution is adjusted to 0.005 to 0.05 mol/1, in particular 0.015 to 0.027 mo1/1.
However, the fact that rhodium is not readily available gives rise to an unsatisfactory high cost level for this process.
There has therefore been no lack of attempts to exchange the expensive rhodium for a less expensive replacement catalyst.
Nickel is proposed as replacement catalyst for carbonylations of methyl acetate or dianethyl ether for the preparation of acetic anhydride, for example in _, 2p~~~2~
The invention relates to a continuous process for the simultaneous preparation of acetic acid and acetic anhydride by reaction of mixtures of methanol and methyl acetate and also, optionally, dimethyl ether with carbon monoxide.
Acetic acid and acetic anhydride are intermediates for the vinyl acetate and cellulose acetate products Which to an increasing extent are being prepared industrially.
DE-3 823 645 C1 discloses a process for the simultaneous preparation of acetic acid and acetic anhydride by a carbonylation of methanol and methyl acetate in 'the presence of a catalyst system which contains carbonyl complexes of noble metals of group VIII of the periodic system of the elements. Rhodium in particular is a catalyst constituent of outstanding activity. The rhodium concentration in the reaction solution is adjusted to 0.005 to 0.05 mol/1, in particular 0.015 to 0.027 mo1/1.
However, the fact that rhodium is not readily available gives rise to an unsatisfactory high cost level for this process.
There has therefore been no lack of attempts to exchange the expensive rhodium for a less expensive replacement catalyst.
Nickel is proposed as replacement catalyst for carbonylations of methyl acetate or dianethyl ether for the preparation of acetic anhydride, for example in _, 2p~~~2~
DE-31 51 371 C2. Disadvantages of working with this replacement catalyst are the low space-time yield and the high nickel salt concentrations which have to be used in order to achieve industrially usable conversions. This leads to difficulties in particular if the carbonylation is to be operated as a continuous process.
A nickel catalyst for carbonylations of methanol for the preparation of acetic acid is also proposed in DE-27 49 955 C2. In order to preserve the catalyst activity during continuous operation, the carbon monoxide is employed together with hydrogen. A disadvantage of this is that, as a result of the addition of hydrogen, the selectivity, as a result of the formation of ethylidene diacetate, and the space-time yield for 'the same CO total pressure are impaired. In this case also a high catalyst concentration must be maintained, which leads to difficulties in the case of continuous opera-tion.
The object was, therefore, to prepare both acetic acid and acetic anhydride in the same reaction system in a continuous process, a high. space-tune yield being achieved with high selectivity in moderate pressure ranges, low corrosion occurring on the reactor and it being possible to adapt the process in accordance with the particular economic requirements in a simple manner to the ratio of acetic acid to acetic anhydride.
_ 3 The present invention thus relates to a continuous process for the simultaneous preparation of acetic acid and acetic anhydride from a starting mixture of methanol and methyl acetate and also, optionally, dimethyl ether, by reaction with carbon monoxide under anhydrous conditions at temperatures of 150 to 250°C and under elevated pressure in a reaction zone on a dissolved catalyst system containing a nickel compound, methyl iodide as promoter, at least one co-promoter, such as an alkali metal iodide, quaternary phosphonium iodide or quaternary ammonium iodide, and a co-catalyst, which process comprises using, a co-catalyst, a rhodium or iridium compound in a molar ratio of nickel: co-catalyst of to (0.005 to 0.1), adjusting the nickel concentration in the reaction zone to 0.01 to 0.1., preferably to 0.015 to 0.06 moll, and operating under an elevated pressure of 30 to 100 bar, in particular of 50 to 80 bar.
The process of the invention can, furthermore, preferably comprise adjusting the residence time in 'the reaction zone to 1 to ZO minutes.
Co-promoters which have given good results in the process according to the invention are, in particular, hil, NaI, methyltributylphosphanium iodide, methyltri-phenylphosphonium iodide, tetrabutylphosphonium iodide or dimethyldibutylphosphonium iodide and also N,N-dimethyl-imidazolium iodide, N-methylpyridinium iodide, N-methyl-3-picolinium iodide or N-methylquinolinium ~~~3~2~
iodide in amounts of 0.05 to 4.5 molll of reaction solution.
The ratio of methanol to methyl acetate or dimethyl ether can be selected within wide limits. A molar ratio of methanol: methyl acetate and/or da.methyl ether of 10 : 1 to 1 : 10 has proved suitable for good space-time yields .
Minor contamination of the carbon monoxide by hydrogen, water vapor and CO2, CHI, or other inert gases is of no significance.
Temperatures above 250°C promote the formation of tar-like constituents, which interfere when separating the catalyst system from the products.
The reaction solution preferably contains 0.1 to 7.5 mol/1 of methyl iodide as promoter.
The nickel compound can be added in the form of nickel chloride, nickel iodide, nickel acetate or nickel acetylacetonate and also in the form of nickel tetra-carbonyl.
Suitable rhodium and iridium compounds are the corresr ponding chlorides and iodides or complex compounds such as, for example, ~CHsp~C<<Hs)sl ~~CC)Ia or C CH3p ~ C4H~J ) 3 _5_ A batchwise preparation of acetic acid and acetic anhydride is also possible using the catalyst system according to the invention; however, the catalyst system according to the invention displays its good characteristics in the continuous procedure. In the case of the continuous procedure, the catalyst system maintains its full catalyst activity in respect of the suppression of secondary reactions and high space-time yields over prolonged operating periods. No salt deposits are formed during the continuous procedure. As a result of the small amount of rhodium or iridium used, the catalyst costs are substantially reduced. The anhydrous procedure gives rise to only an insignificant introduction of corrosion products into the reaction solution.
Although the catalyst system can also be used for the preparation of higher alkanoic acids and alkanoic anhydrides, it exhibits its best results in the preparation of acetic acid and acetic anhydride. The use of ethanol/methyl acetate or methanol/ethyl acetate mixtures also permits the preparation of mixtures of acetic acid/propionic acid/acetic anhydride/propionic anhydride and the mixed anhydride of acetic acid and propionic acid.
Figure 1 represents, by way of example, one embodiment of a process for the simultaneous production of acetic acid and acetic anhydride in accordance with the invention.
Example 1 The carbonylation is carried out at a temperature of 190° under a pressure of 70 bar in a reactor having a useful volume of 4.5 1. The reaction solution in the reactor contains, on average, 0.060 rnol/1 of nickel iodide, 0.002 mol/1 of rhodium trichloride, 0.676 mo1/1 of rnethyltributylphosphonium iodide and 2.3 mol/1 of methyl iodide.
Per hour, 0.79 kg (10.7 mol) of methyl. acetate, 1.67 kg (52.1 mol) of methanol and 11.7 kg of low-boiling compounds (methyl acetate, methyl iodide) are fed to the reactor 2 via the feedline 7. 1.76 kg/h (62.8 mol/h) of carbon monoxide are injected into the reactor 2 via line 3. At the same time, 9.8 kg/h of distillation bottom, in which the catalyst system is dissolved, are metered in via the return line 4 from the evaporation stage 12 into the reactor 2. An average residence time in reactor 2 of 10 minutes is calculated from these figures .
Via the product line 5, 22.9 kg/h of reaction solution are fed through the extraction valve 6 in the liquid phase to the separator 8. From the separator 8, which is operated at a pressure of 1 bar and at 95°C, the liquid product flows through line 11 into the evaporation stage 12; the gaseous fractions from the separator 8 and the evaporation stage 12 flow through the lines 9 and 13 into the column 10 for low-boiling compounds. 0.07 kg/h of inert gases are discharged from the condenser 14 via the off-gas line 22. The low~boiling compounds (methyl iodide, methyl acetate) are separated off in the column 10 for low-boiling compounds, under a pressure of 1 bar at a bottom temperature of 126°C and a top temperature of 70°C, and are recycled from the condenser 14 via line 1 into the reactor 2. 4.22 kg/h of bottom product are fed via the drain line 15 into the column 16, which is operated under a pressure of 0.15 bar at a top temperature of 70°C and a bottom temperature of 99°C. 3.07 kglh of pure acetic acid are drawn off as top product from the column 16 via the product line 20. A
yield of 98'x, based on methanol employed, is calculated from these figures.
The bottom product is transferred via the drain line 17 into the column 18, which is operated under a pressure of 0.15 bar at a top temperature of 90°C and a bottom temperature of 104°C. 1.08 kg/h of pure acetic anhydride are withdrawn as top product from the column 18 via the product line 21. A yield of 99~, haled on methyl acetate employed, as calculated from 'these figures.
0.07 kg/h of high-boiling compounds are removed as bottom product from the column 18 via the bottom line 19.
The yield of acetic acid and acetic anhydride corresponds to 98.1, based on the CO conversion.
The space-time yield is 922 g of acetic acid and acetic anhydride/1 . h.
Example 2 Example 1 was modified in that, per hour, 0.79 kg (10.7 mol) of methyl acetate, 2.43 kg (75.9 mol) of methanol, via feedline 7, and 2.42 kg/h of C0, via line 3, were metered in.
A residence time of 9 minutes in the reactor 2 is calculated from these figuxes.
The yield of acetic acid and acetic anhydride corresponds to 98~, based on the CO conversion.
4.49 kg/h of pure acetic acid and 1.07 kg/h of pure acetic anhydride were obtained.
The space-.time yield is 1236 g'of acetic acid arid acetic anhydride/1 . h.
A nickel catalyst for carbonylations of methanol for the preparation of acetic acid is also proposed in DE-27 49 955 C2. In order to preserve the catalyst activity during continuous operation, the carbon monoxide is employed together with hydrogen. A disadvantage of this is that, as a result of the addition of hydrogen, the selectivity, as a result of the formation of ethylidene diacetate, and the space-time yield for 'the same CO total pressure are impaired. In this case also a high catalyst concentration must be maintained, which leads to difficulties in the case of continuous opera-tion.
The object was, therefore, to prepare both acetic acid and acetic anhydride in the same reaction system in a continuous process, a high. space-tune yield being achieved with high selectivity in moderate pressure ranges, low corrosion occurring on the reactor and it being possible to adapt the process in accordance with the particular economic requirements in a simple manner to the ratio of acetic acid to acetic anhydride.
_ 3 The present invention thus relates to a continuous process for the simultaneous preparation of acetic acid and acetic anhydride from a starting mixture of methanol and methyl acetate and also, optionally, dimethyl ether, by reaction with carbon monoxide under anhydrous conditions at temperatures of 150 to 250°C and under elevated pressure in a reaction zone on a dissolved catalyst system containing a nickel compound, methyl iodide as promoter, at least one co-promoter, such as an alkali metal iodide, quaternary phosphonium iodide or quaternary ammonium iodide, and a co-catalyst, which process comprises using, a co-catalyst, a rhodium or iridium compound in a molar ratio of nickel: co-catalyst of to (0.005 to 0.1), adjusting the nickel concentration in the reaction zone to 0.01 to 0.1., preferably to 0.015 to 0.06 moll, and operating under an elevated pressure of 30 to 100 bar, in particular of 50 to 80 bar.
The process of the invention can, furthermore, preferably comprise adjusting the residence time in 'the reaction zone to 1 to ZO minutes.
Co-promoters which have given good results in the process according to the invention are, in particular, hil, NaI, methyltributylphosphanium iodide, methyltri-phenylphosphonium iodide, tetrabutylphosphonium iodide or dimethyldibutylphosphonium iodide and also N,N-dimethyl-imidazolium iodide, N-methylpyridinium iodide, N-methyl-3-picolinium iodide or N-methylquinolinium ~~~3~2~
iodide in amounts of 0.05 to 4.5 molll of reaction solution.
The ratio of methanol to methyl acetate or dimethyl ether can be selected within wide limits. A molar ratio of methanol: methyl acetate and/or da.methyl ether of 10 : 1 to 1 : 10 has proved suitable for good space-time yields .
Minor contamination of the carbon monoxide by hydrogen, water vapor and CO2, CHI, or other inert gases is of no significance.
Temperatures above 250°C promote the formation of tar-like constituents, which interfere when separating the catalyst system from the products.
The reaction solution preferably contains 0.1 to 7.5 mol/1 of methyl iodide as promoter.
The nickel compound can be added in the form of nickel chloride, nickel iodide, nickel acetate or nickel acetylacetonate and also in the form of nickel tetra-carbonyl.
Suitable rhodium and iridium compounds are the corresr ponding chlorides and iodides or complex compounds such as, for example, ~CHsp~C<<Hs)sl ~~CC)Ia or C CH3p ~ C4H~J ) 3 _5_ A batchwise preparation of acetic acid and acetic anhydride is also possible using the catalyst system according to the invention; however, the catalyst system according to the invention displays its good characteristics in the continuous procedure. In the case of the continuous procedure, the catalyst system maintains its full catalyst activity in respect of the suppression of secondary reactions and high space-time yields over prolonged operating periods. No salt deposits are formed during the continuous procedure. As a result of the small amount of rhodium or iridium used, the catalyst costs are substantially reduced. The anhydrous procedure gives rise to only an insignificant introduction of corrosion products into the reaction solution.
Although the catalyst system can also be used for the preparation of higher alkanoic acids and alkanoic anhydrides, it exhibits its best results in the preparation of acetic acid and acetic anhydride. The use of ethanol/methyl acetate or methanol/ethyl acetate mixtures also permits the preparation of mixtures of acetic acid/propionic acid/acetic anhydride/propionic anhydride and the mixed anhydride of acetic acid and propionic acid.
Figure 1 represents, by way of example, one embodiment of a process for the simultaneous production of acetic acid and acetic anhydride in accordance with the invention.
Example 1 The carbonylation is carried out at a temperature of 190° under a pressure of 70 bar in a reactor having a useful volume of 4.5 1. The reaction solution in the reactor contains, on average, 0.060 rnol/1 of nickel iodide, 0.002 mol/1 of rhodium trichloride, 0.676 mo1/1 of rnethyltributylphosphonium iodide and 2.3 mol/1 of methyl iodide.
Per hour, 0.79 kg (10.7 mol) of methyl. acetate, 1.67 kg (52.1 mol) of methanol and 11.7 kg of low-boiling compounds (methyl acetate, methyl iodide) are fed to the reactor 2 via the feedline 7. 1.76 kg/h (62.8 mol/h) of carbon monoxide are injected into the reactor 2 via line 3. At the same time, 9.8 kg/h of distillation bottom, in which the catalyst system is dissolved, are metered in via the return line 4 from the evaporation stage 12 into the reactor 2. An average residence time in reactor 2 of 10 minutes is calculated from these figures .
Via the product line 5, 22.9 kg/h of reaction solution are fed through the extraction valve 6 in the liquid phase to the separator 8. From the separator 8, which is operated at a pressure of 1 bar and at 95°C, the liquid product flows through line 11 into the evaporation stage 12; the gaseous fractions from the separator 8 and the evaporation stage 12 flow through the lines 9 and 13 into the column 10 for low-boiling compounds. 0.07 kg/h of inert gases are discharged from the condenser 14 via the off-gas line 22. The low~boiling compounds (methyl iodide, methyl acetate) are separated off in the column 10 for low-boiling compounds, under a pressure of 1 bar at a bottom temperature of 126°C and a top temperature of 70°C, and are recycled from the condenser 14 via line 1 into the reactor 2. 4.22 kg/h of bottom product are fed via the drain line 15 into the column 16, which is operated under a pressure of 0.15 bar at a top temperature of 70°C and a bottom temperature of 99°C. 3.07 kglh of pure acetic acid are drawn off as top product from the column 16 via the product line 20. A
yield of 98'x, based on methanol employed, is calculated from these figures.
The bottom product is transferred via the drain line 17 into the column 18, which is operated under a pressure of 0.15 bar at a top temperature of 90°C and a bottom temperature of 104°C. 1.08 kg/h of pure acetic anhydride are withdrawn as top product from the column 18 via the product line 21. A yield of 99~, haled on methyl acetate employed, as calculated from 'these figures.
0.07 kg/h of high-boiling compounds are removed as bottom product from the column 18 via the bottom line 19.
The yield of acetic acid and acetic anhydride corresponds to 98.1, based on the CO conversion.
The space-time yield is 922 g of acetic acid and acetic anhydride/1 . h.
Example 2 Example 1 was modified in that, per hour, 0.79 kg (10.7 mol) of methyl acetate, 2.43 kg (75.9 mol) of methanol, via feedline 7, and 2.42 kg/h of C0, via line 3, were metered in.
A residence time of 9 minutes in the reactor 2 is calculated from these figuxes.
The yield of acetic acid and acetic anhydride corresponds to 98~, based on the CO conversion.
4.49 kg/h of pure acetic acid and 1.07 kg/h of pure acetic anhydride were obtained.
The space-.time yield is 1236 g'of acetic acid arid acetic anhydride/1 . h.
Claims (8)
1. A continuous process for the simultaneous prepara-tion of acetic acid and acetic anhydride, which comprises reacting a starting mixture of methanol and methyl acetate with carbon monoxide under anhydrous conditions at temperatures of 150 to 250°C
and under pressures of 30 to 100 bar in a reaction zone on a dissolved catalyst system, the catalyst system containing a nickel compound in a concen-tration of 0.01 to 0.1 mol/l, methyl iodide as promoter, at least one co-promoter and, as co-catalyst, a rhodium or iridium compound in a molar ratio of nickel: co-catalyst of to (0.005 to 0.1).
and under pressures of 30 to 100 bar in a reaction zone on a dissolved catalyst system, the catalyst system containing a nickel compound in a concen-tration of 0.01 to 0.1 mol/l, methyl iodide as promoter, at least one co-promoter and, as co-catalyst, a rhodium or iridium compound in a molar ratio of nickel: co-catalyst of to (0.005 to 0.1).
2. The process as claimed in claim 1, wherein the residence time in the reaction zone is adjusted to 1 to 10 minutes.
3. The process as claimed in claim 1, wherein the starting mixture additionally contains dimethyl ether.
4. The process as claimed in claim 1, wherein the co-promoter used is an alkali metal iodide.
5. The process as claimed in claim 1, wherein the co promoter used is quaternary phosphonium iodide.
6. The process as claimed in claim 1, wherein the co-promoter used is quaternary ammonium iodide.
7. The process as claimed in claim 1, wherein the nickel compound is present in a concentration of 0.015 to 0.06 moll.
8. The process as claimed in claim 1, wherein the reaction is carried out under pressures of 50 to 80 bar.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4034867A DE4034867A1 (en) | 1990-11-02 | 1990-11-02 | CONTINUOUS PROCESS FOR THE SIMULTANEOUS PRODUCTION OF ACETIC ACID AND ACETIC ACID ANHYDRIDE |
| DEP4034867.9 | 1990-11-02 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2053828A1 CA2053828A1 (en) | 1992-05-03 |
| CA2053828C true CA2053828C (en) | 2002-04-23 |
Family
ID=6417522
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002053828A Expired - Lifetime CA2053828C (en) | 1990-11-02 | 1991-10-21 | Continuous process for the simultaneous preparation of acetic acid and acetic anhydride |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0483536B1 (en) |
| JP (1) | JP3084107B2 (en) |
| KR (1) | KR920009766A (en) |
| CN (1) | CN1032133C (en) |
| AT (1) | ATE116960T1 (en) |
| AU (1) | AU641056B2 (en) |
| CA (1) | CA2053828C (en) |
| DE (2) | DE4034867A1 (en) |
| ZA (1) | ZA918701B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4029917A1 (en) * | 1990-09-21 | 1992-03-26 | Hoechst Ag | METHOD FOR THE SIMULTANEOUS PRODUCTION OF ACETIC ACID AND ACETIC ACID ANHYDRIDE |
| GB9120902D0 (en) * | 1991-10-02 | 1991-11-13 | Bp Chem Int Ltd | Purification process |
| FR2735399B1 (en) * | 1995-06-16 | 1997-07-25 | Inst Francais Du Petrole | NOVEL CATALYTIC COMPOSITION BASED ON TRANSITIONAL METAL COMPLEXES AND METHOD FOR THE HYDROGENATION OF UNSATURATED COMPOUNDS |
| GB0213485D0 (en) | 2002-06-12 | 2002-07-24 | Bp Chem Int Ltd | Process |
| EP2231568B1 (en) * | 2007-11-14 | 2014-04-30 | BP p.l.c. | Process for the production of ethanol from ethanoic acid and hydrogen |
| EP2186787A1 (en) * | 2008-11-13 | 2010-05-19 | BP p.l.c. | Hydrogenation of ethanoic acid to produce ethanol |
| US9012683B2 (en) * | 2010-11-12 | 2015-04-21 | Eastman Chemical Company | Coproduction of acetic acid and acetic anhydride |
| US9981896B2 (en) | 2016-07-01 | 2018-05-29 | Res Usa, Llc | Conversion of methane to dimethyl ether |
| US10189763B2 (en) | 2016-07-01 | 2019-01-29 | Res Usa, Llc | Reduction of greenhouse gas emission |
| US9938217B2 (en) | 2016-07-01 | 2018-04-10 | Res Usa, Llc | Fluidized bed membrane reactor |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3717670A (en) * | 1968-08-02 | 1973-02-20 | Monsanto Co | Production of carboxylic acids and esters |
| DE3429180A1 (en) * | 1984-08-08 | 1986-02-20 | Hoechst Ag, 6230 Frankfurt | METHOD FOR PRODUCING ACETIC ACID ANHYDRIDE AND GGF. ACETIC ACID |
| 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 |
-
1990
- 1990-11-02 DE DE4034867A patent/DE4034867A1/en not_active Withdrawn
-
1991
- 1991-10-02 AT AT91116823T patent/ATE116960T1/en not_active IP Right Cessation
- 1991-10-02 DE DE59104235T patent/DE59104235D1/en not_active Expired - Lifetime
- 1991-10-02 EP EP91116823A patent/EP0483536B1/en not_active Expired - Lifetime
- 1991-10-21 CA CA002053828A patent/CA2053828C/en not_active Expired - Lifetime
- 1991-10-31 JP JP03286331A patent/JP3084107B2/en not_active Expired - Lifetime
- 1991-10-31 KR KR1019910019232A patent/KR920009766A/en not_active Withdrawn
- 1991-11-01 ZA ZA918701A patent/ZA918701B/en unknown
- 1991-11-01 AU AU87003/91A patent/AU641056B2/en not_active Ceased
- 1991-11-01 CN CN91108391A patent/CN1032133C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| ZA918701B (en) | 1992-08-26 |
| ATE116960T1 (en) | 1995-01-15 |
| DE4034867A1 (en) | 1992-05-07 |
| KR920009766A (en) | 1992-06-25 |
| JP3084107B2 (en) | 2000-09-04 |
| EP0483536B1 (en) | 1995-01-11 |
| CA2053828A1 (en) | 1992-05-03 |
| AU641056B2 (en) | 1993-09-09 |
| DE59104235D1 (en) | 1995-02-23 |
| EP0483536A3 (en) | 1992-11-25 |
| AU8700391A (en) | 1992-05-07 |
| CN1032133C (en) | 1996-06-26 |
| EP0483536A2 (en) | 1992-05-06 |
| CN1061022A (en) | 1992-05-13 |
| JPH04264049A (en) | 1992-09-18 |
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