GB1561534A - Process for the manufacture of ethyl acetate - Google Patents
Process for the manufacture of ethyl acetate Download PDFInfo
- Publication number
- GB1561534A GB1561534A GB4275876A GB4275876A GB1561534A GB 1561534 A GB1561534 A GB 1561534A GB 4275876 A GB4275876 A GB 4275876A GB 4275876 A GB4275876 A GB 4275876A GB 1561534 A GB1561534 A GB 1561534A
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- United Kingdom
- Prior art keywords
- acetic acid
- ethylene
- catalyst
- sulphate
- range
- Prior art date
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- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 title claims description 92
- 238000000034 method Methods 0.000 title claims description 81
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 240
- 239000003054 catalyst Substances 0.000 claims description 51
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 50
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 49
- 239000005977 Ethylene Substances 0.000 claims description 49
- -1 alkyl sulphate Chemical compound 0.000 claims description 42
- 239000000203 mixture Substances 0.000 claims description 30
- 238000006243 chemical reaction Methods 0.000 claims description 28
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 25
- 239000001117 sulphuric acid Substances 0.000 claims description 25
- 235000011149 sulphuric acid Nutrition 0.000 claims description 25
- 239000000377 silicon dioxide Substances 0.000 claims description 23
- 235000012239 silicon dioxide Nutrition 0.000 claims description 23
- 229910021653 sulphate ion Inorganic materials 0.000 claims description 22
- KIWBPDUYBMNFTB-UHFFFAOYSA-N Ethyl hydrogen sulfate Chemical compound CCOS(O)(=O)=O KIWBPDUYBMNFTB-UHFFFAOYSA-N 0.000 claims description 6
- 239000007789 gas Substances 0.000 claims description 6
- 230000015572 biosynthetic process Effects 0.000 claims description 5
- DENRZWYUOJLTMF-UHFFFAOYSA-N diethyl sulfate Chemical compound CCOS(=O)(=O)OCC DENRZWYUOJLTMF-UHFFFAOYSA-N 0.000 claims description 5
- 238000001035 drying Methods 0.000 claims description 4
- KIWBPDUYBMNFTB-UHFFFAOYSA-M ethyl sulfate Chemical compound CCOS([O-])(=O)=O KIWBPDUYBMNFTB-UHFFFAOYSA-M 0.000 claims description 3
- 238000004508 fractional distillation Methods 0.000 claims description 3
- 241000272168 Laridae Species 0.000 claims description 2
- 230000002378 acidificating effect Effects 0.000 claims description 2
- 150000001875 compounds Chemical class 0.000 claims description 2
- 229910003556 H2 SO4 Inorganic materials 0.000 claims 1
- 239000002253 acid Substances 0.000 description 9
- 239000000047 product Substances 0.000 description 8
- 239000011541 reaction mixture Substances 0.000 description 8
- 229910052681 coesite Inorganic materials 0.000 description 5
- 229910052906 cristobalite Inorganic materials 0.000 description 5
- 229910052682 stishovite Inorganic materials 0.000 description 5
- 229910052905 tridymite Inorganic materials 0.000 description 5
- 150000007513 acids Chemical class 0.000 description 4
- 239000012071 phase Substances 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 3
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 3
- 238000005470 impregnation Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 238000004821 distillation Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010574 gas phase reaction Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- 238000006116 polymerization reaction Methods 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- 239000004922 lacquer Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/04—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides onto unsaturated carbon-to-carbon bonds
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Description
(54) PROCESS FOR THE MANUFACTURE OF ETHYL ACETATE
(71) We, HOECHST AKTIENGESELL
SCHAFT, a Body Corporate organised according to the laws of the Federal Republic of
Germany, of 6230 Frankfurt (Main) 80, Post fach 80 03 20, Federal Republic of Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a process for the manufacture of ethyl acetate from acetic acid and ethylene.
In previously proposed processes for the manufacture of ethyl acetate, for example, as described by Y. Murakami, T. Hattori and
H. Uchida in J. Chem. Soc. Japan, Ind. Chem.
Sect. (Kogyo Kagaku Zasshi) 72 (9), 1945 1948 (1969), oxides of chromium, molybdenum and tungsten in the form of different heteropoly acids have been used as catalysts for the gas phase reaction of acetic acid and ethylene. These catalysts show a certain initial activity at relatively high temperature, for example, in excess of 200"C, and under a pressure of up to 150 bars, but become relatively inactive after only a few hours. Catalysts containing phosphoric acid (H3P04) to be used for the gas phase reaction are unsuitable because of their low activity, while acid ion exchange resins cannot be used due to their instability at temperatures approaching reaction temperature.
Considerable difficulties also arise when conducting the reaction in the liquid phase. In one previously proposed reaction, 96% sulphuric acid was used as a catalyst, at a concentration of 67% of the acetic acid starting material.
However, this process suffers from the disadvantage that, as high concentrations of mineral acids lead to partial polymerization of ethylene, some of the ethylene is lost, and the polymeric by-products are difficult to remove from the resulting catalyst solution. A further disadvantage in using high concentrations of mineral acids is due to the corrosion caused by the acids which hinders their use on an industrial scale.
The present invention provides a process for the manufacture of ethyl acetate by reaction of acetic acid with ethylene in the gas phase, which comprises contacting acetic acid with ethylene in the presence of a catalyst comprising silicon dioxide impregnated with sulphuric acid, and alkyl sulphate, an alkyl hydrogen sulphate or a mixture thereof.
One advantage of the present invention is that the efficiency of the catalyst often remains substantially unchanged after more than 100 hours under the reaction conditions. Another advantage is that relatively little ethylene is lost due to polymerization. Formation of byproducts or undesired consecutive products is, in many cases, not observed.
The catalyst preferably comprises sulphuric acid, ethyl sulphate, ethyl hydrogen sulphate or a mixture thereof. The silicon dioxide may have a specific surface area in the range of from 50 to 200 m2g' preferably in the range of from 80 to 170 m g While specific surface areas outside this range may be used, the yield of ethyl acetate is generally reduced.
The catalyst, which is usually in the form of a fixed-bed catalyst, may generally be prepared by impregnating silicon dioxide with sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate or a mixture thereof, preferably in admixture with acetic acid, and subsequently drying the impregnated silicon dioxide under a reduced pressure, and preferably at a temperature of about 140"C.
The quantity of sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate or mixture thereof in the catalyst may be in the range of 10 to 30% by weight, optionally after removal of the acetic acid by drying.
In the preferred process, gaseous ethylene and acetic acid are passed through a reaction zone of a reactor, in which the catalyst is arranged as a fixed-bed. The acetic acid may either be passed over a preevaporator or be led directly to the reaction zone, where it vaporizes immediately under the reaction conditions.
The reaction zone may be situated inside a heatable tube, for example made of glass or stainless steel. Other reactor forms and materials however may also be used.
In general, the molar ratio of acetic acid to ethylene contracted with the catalyst does not exceed 0.4, and preferably does not exceed 0.3, while the minimum value of the ratio is generally 0.0001-0.001.
The ratio of the quantity of acetic acid to that of ethylene contacted with the catalyst is advantageously varied with time, such variation preferably being achieved by varying the quantity of acetic acid introduced into the reactor, so that the quantity of acetic acid contacted with the ethylene is varied with time.
Thus, for example, the said variation may be achieved by introducing the acetic acid over a time interval and then interrupting the introduction for a period of time before introducing further acid over the said time interval, the addition being regulated by means of a time switch.
The preferred duration of the intervals in which the acid is introduced or the introduction is discontinued depends to some extent on the desorption velocity of the acetic acid from the catalyst under the reaction conditions. As acetic acid is absorbed by the catalyst to a higher degree than ethylene, the catalytically active surface of the catalyst is covered substantially completely with acetic acid after a short period of time if the addition of acetic acid is not interrupted, thus reducing the quantity of ethylene absorbed and consequently the rate of ester formation.In the preferred process, therefore, acetic acid is introduced into the reactor for a time interval of from 2 to 60 minutes, preferably 5 to 30 minutes, and the addition is then interrupted for 0.1 to 15 minutes, preferably 1 to 10 minutes, before introducing further acetic acid, the ethylene being added without interruption.
By this process, part of the acetic acid absorbed by the catalyst is desorbed during interruption of the acid introduction so that a sufficient quantity of ethylene is adsorbed. The duration of each interruption may be the same and, additionally or alternatively, the time between each interruption may be the same.
If the material load of the catalyst is too high during the reaction a small discharge of impregnated material may occur so that the activity of the catalyst may be slightly reduced in the course of several hundred hours. In such cases it is advantageous to introduce sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate or a mixture thereof into the reactor together with the reaction components, for example, dissolved in the acetic acid, of from 0.1 to 2% by weight, based on the weight of acetic acid introduced into the reactor.
The reaction product may be worked up continuously or discontinuously in known manner. The preferred method consists of separating the reaction mixture continuously while isolating pure ethyl acetate. For this purpose the reaction mixture is cooled after having left the reactor, so that ethyl acetate and nonconverted acetic acid condense, while nonconverted ethylene remains in the gas phase and is recycled to the reactor. The condensate is then preferably continuously submitted to a fractional distillation, in which non-converted acetic acid is recovered from the bottom product of the distillation column and recycled to the reactor, and pure ethyl acetate is obtained at the top of the column.
Advantageously, any sulphuric acid, alkyl sulphate or alkyl hydrogen sulphate in the product mixture is recovered.
The reaction temperature may be in the range of from 130 to 1700C, preferably from 140 to 1500C, although slightly higher or lower temperatures are also possible.
The reaction may be conducted under a pressure of up to 100 bars, although a pressure of from 0.5 to 10 bars is usually used.
The present invention further provides a process for the manufacture of ethyl acetate by reaction of acetic acid and ethylene in the gas phase in the presence of acidic catalysts, which comprises passing ethylene over a fixed-bed catalyst with periodically alternating quantities of acetic acid at a temperature of from 130 to 1700 C, the catalyst being composed of silicon dioxide having a surface from 50 to 200 m2 /g and being impregnated with H2S04, diethylsulphate or ethylsulphuric acid or mixtures of these compounds, the acetic acid concentration calculated on ethylene varying constantly over a range from 0.01 to 40% by mole.
The selectivity of the process according to the invention is extremely high; it is nearly 100%, referring to acetic acid as well as to ethylene.
Ethyl acetate is used to a considerable extent, for example, as a solvent for lacquers and adhesives.
The following Examples illustrate the invention:
EXAMPLES 1 to 3:
A total of 10 ml/h of acetic acid is introduced by pumping alternatingly by means of a disage pump, while simultaneously adding 20 Nl/h of ethylene, at the top of a vertically arranged glass tube reactor of 30 cm length and 100 ml volume, which is filled with about 100 ml of a catalyst composed of Si02, impregnated with 25% by weight of H2 S04 and having a surface area as indicated in Table 1, and which is heated to a temperature of 138"C, the acetic acid addition being interrupted constantly for 2 minutes after 6 minutes.The product mixture leaving the reactor is brought to normal temperature, separated from excess ethylene and analysed.Apart from unconverted acetic acid only ethyl acetate is present, so that the selectivity calculated on converted ethylene and on converted acetic acid are practically 100%.
Table 1 indicates the content of ethyl acetate in the product mixture separated from ethylene in Examples 1 to 3. The unconverted portions of ethylene and acetic acid may be recirculated to the reactor without purifying operations.
TABLE I Influence of the catalyst surface on the conversion.
Example Si02-surface % by weight of ethyl
(m2/g) acetate in the
reaction mixture 110 34.2
2 120 60.0
3 160 37.4
EXAMPLES 4 to 5:
The reaction is performed as in Examples 1 to 3, except that catalysts having a Si02 surface areas outside the range of 50 to 200 mg' are used. Table 2 shows the results obtained. The quantities of ethyl acetate in the reaction mixture are noticeably smaller.
TABLE 11 Influence of the catalyst surface on the conversion
Example Si02 -surface % by weight of ethyl
(m2/g) acetate in the
reaction mixture
4 0.6 14.6
5 350 10.0
EXAMPLES 6 to 9:
The apparatus described in the Examples 1 to 3 is filled each time with 100 ml of a catalyst (carrier: SiO2 having a surface of 120 m2/g) provided with the impregnation indicated in
Table 3 and fed with ethylene and acetic acid in an analogous manner to Examples 1 to 3.
The reaction temperature in the reactor is 144 C. Table 3 indicates the quantities of ethyl acetate in the product mixture.
The selectivity, calculated on converted acetic acid and on converted ethylene, in the
Examples 6 to 9 are 100%.
TABLE 111
Influence of the catalyst impregnation on the conversion
Example Impregnation % by weight of ethyl
by weight acetate in the
(each time reaction mixture
20% by weight)
6 H2S04 61.5
7 diethylsulphate 59.2
8 ethylsulphuric acid 59.7
9 H2 S04idiethyl- 60.4
sulphate 1:1
EXAMPLES 10 to 12:
800 Nl/h of ethylene and periodically acetic acid having a content of diethylsulphate of 0.7% by weight are introduced continuously at the top of a vertically arranged V4A-stainless steel reactor of 100 cm length, which is filled with 250 ml of catalyst (Si02, 120 m2/g, 25% by weight of diethylsulphate), at a temperature of 147 C. The periodic acetic acid addition is carried ot in the following manner:
The addition is interrupted each time for one interval after 5 dosing intervals.A total of 150 ml/h of acetic acid is metered into the reactor. The pressure in the reactor is 6 bars.
The reaction mixture leaving the reactor is worked up continuously. The excess ethylene is recycled to the reactor. The portion of the reaction mixture liquid at normal temperature is fractionated in a distillation column. The ethyl acetate is withdrawn at the top of the column. A mixture containing, besides small quantities of ethyl acetate, unconverted acetic acid is recycled to the reactor continuously from the bottom. Table 4 indicates the different intervals of the alternating acetic acid addition of the Examples 10 to 12 as well as the space-time-yields obtained. The selectivities for acetic acid ethyl ester, calculated on converted ethylene and converted acetic acid, are in all cases 100%.
TABLE IV Example intervals of the acetic Space-time
acid addition (min) yield of ethyl
acetate for
addition without mation
addition (gll.h)
10 5 1 205
11 12.5 2.5 178
12 2.5 5 164
The same values for the yield of the ethyl acetate formation as well as the same selectivity are obtained even after a continuous operation time of more than 1000 hours.
EXAMPLE 13:
When operating in the same manner as in the
Examples 10 to 12, except that the acetic acid addition is not performed periodically, but that 150 ml/h of acetic acid are added without interruption, the yield of the ethyl acetate formation is only 100 gull. h.
WHAT WE CLAiM IS:
1. A process for the manufacture of ethyl acetate by reaction of acetic acid with ethylene in the gas phase, which comprises contacting acetic acid with ethylene in the presence of a catalyst comprising silicon dioxide impregnated with sulphuric acid, an alkyl sulphate, an alkyl hydrogen sulphate or a mixture thereof.
2. A process as claimed in claim 1, wherein the catalyst comprises silicon dioxide impregnated with sulphuric acid, ethyl sulphate, ethyl hydrogen sulphate or a mixture thereof.
3. A process as claimed in claim 1 or claim 2, wherein the silicon dioxide has a specific surface area in the range of from 50 to 200 m2g 1.
4. A process as claimed in claim 3, wherein the silicon dioxide has a specific surface area in the range of from 80 to 170 m2 g-'.
5. A process as claimed in any one of claims 1 to 4, wherein the porportion of sulphuric acid, alkyl sulphate or alkyl hydrogen sulphate in the catalyst is in the range of from 10 to 30 percent by weight.
6. A process as claimed in any one of claims 1 to 5, wherein the catalyst is a fixedbed catalyst.
7. A process as claimed in any one of claims 1 to 6, wherein the catalyst has been prepared by impregnating silicon dioxide with sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate or a mixture thereof, and subsequently drying the impregnated silicon dioxide under reduced pressure.
8. A process as claimed in claim 7, wherein the silicon dioxide has been impregnated with acetic acid and sulphuric acid, an alkyl sulphate, an alkyl hydrogen sulphate or a mixture thereof.
9. A process as claimed in claim 7 or claim 8, wherein the impregnated silicon dioxide is dried at a temperature of about 140"C.
10. A process as claimed in any one of claims 1 to 9, wherein the ratio of the quantity of acetic acid to the quantity of ethylene contacted with the catalyst is varied with time.
11. A process as claimed in any one of claims 1 to 10, wherein the molar ratio of acetic acid to ethylene contacted with the catalyst does not exceed 0.4.
12. A process as claimed in claim 11, wherein the said molar ratio of acetic acid to ethylene does not exceed 0.3.
13. A process as claimed in any one of claims 1 to 12, wherein the molar ratio of acetic acid to ethylene contacted with the catalyst is at least 0.0001.
14. A process as claimed in any one of claims 10 to 13, wherein the quantity of acetic acid contacted with the ethylene is varied with time.
15. A process as claimed in claim 14, wherein the introduction of acetic acid is intererupted periodically.
16. A process as claimed in claim 15, wherein the time between each interruption is in the range of from 2 to 60 minutes.
17. A process as claimed in claim 16, wherein the time between each interruption is in the range of from 5 to 30 minutes.
18. A process as claimed in any one of claims 15 to 17, wherein the duration of each interruption is in the range of from 0.1 to 15 minutes.
19. A process as claimed in claim 18, wherein the duration of each interruption is in the range of from 1 to 10 minutes.
20. A process as claimed in any one of claims 15 to 19, wherein the duration of each interruption is the same.
21. A process as claimed in any one of claims 15 to 20, wherein the time between each interruption is the same.
22. A process as claimed in any one of claims 1 to 21, wherein unreacted acetic acid and ethylene are recirculated.
23. A process as claimed in any one of claims 1 to 22, wherein the product mixture is cooled to form a condensate comprising unreacted acetic acid and ethyl acetate, the acetic acid and ethyl acetate being separated by fractional distillation.
24. A process as claimed in any one of claims 1 to 23, wherein any sulphuric acid, alkyl sulphate or alkyl hydrogen sulphate in the product mixture is recovered.
25. A process as claimed in any one of claims 1 to 24, conducted at a temperature in the range of from 130 to 1700C.
26. A process as claimed in claim 25, conducted at a temperature in the range of from 140 to 1500C.
27. A process as claimed in any one of claims 1 to 26, conducted under a pressure of up to 100 bars.
28. A process as claimed in claim 27, conducted under a pressure of from 0.5 to 10 bars.
29. A process as claimed in any one of claims 1 to 28, wherein sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate or a mixture thereof is introduced into the reaction zone.
30. A process as claimed in claim 29, wherein the concentration of sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate, or mixture thereof is in the range of from 0.1 to 2 percent by weight, based on the weight of acetic acid.
31. A process as claimed in claim 29 or claim 30, wherein the sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate or mixture thereof is introduced together with the acetic acid.
32. A process as claimed in any one of claims 1 to 31, wherein the acetic acid is vapourised by introduction into the reaction zone.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (36)
1. A process for the manufacture of ethyl acetate by reaction of acetic acid with ethylene in the gas phase, which comprises contacting acetic acid with ethylene in the presence of a catalyst comprising silicon dioxide impregnated with sulphuric acid, an alkyl sulphate, an alkyl hydrogen sulphate or a mixture thereof.
2. A process as claimed in claim 1, wherein the catalyst comprises silicon dioxide impregnated with sulphuric acid, ethyl sulphate, ethyl hydrogen sulphate or a mixture thereof.
3. A process as claimed in claim 1 or claim 2, wherein the silicon dioxide has a specific surface area in the range of from 50 to 200 m2g 1.
4. A process as claimed in claim 3, wherein the silicon dioxide has a specific surface area in the range of from 80 to 170 m2 g-'.
5. A process as claimed in any one of claims 1 to 4, wherein the porportion of sulphuric acid, alkyl sulphate or alkyl hydrogen sulphate in the catalyst is in the range of from 10 to 30 percent by weight.
6. A process as claimed in any one of claims 1 to 5, wherein the catalyst is a fixedbed catalyst.
7. A process as claimed in any one of claims 1 to 6, wherein the catalyst has been prepared by impregnating silicon dioxide with sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate or a mixture thereof, and subsequently drying the impregnated silicon dioxide under reduced pressure.
8. A process as claimed in claim 7, wherein the silicon dioxide has been impregnated with acetic acid and sulphuric acid, an alkyl sulphate, an alkyl hydrogen sulphate or a mixture thereof.
9. A process as claimed in claim 7 or claim 8, wherein the impregnated silicon dioxide is dried at a temperature of about 140"C.
10. A process as claimed in any one of claims 1 to 9, wherein the ratio of the quantity of acetic acid to the quantity of ethylene contacted with the catalyst is varied with time.
11. A process as claimed in any one of claims 1 to 10, wherein the molar ratio of acetic acid to ethylene contacted with the catalyst does not exceed 0.4.
12. A process as claimed in claim 11, wherein the said molar ratio of acetic acid to ethylene does not exceed 0.3.
13. A process as claimed in any one of claims 1 to 12, wherein the molar ratio of acetic acid to ethylene contacted with the catalyst is at least 0.0001.
14. A process as claimed in any one of claims 10 to 13, wherein the quantity of acetic acid contacted with the ethylene is varied with time.
15. A process as claimed in claim 14, wherein the introduction of acetic acid is intererupted periodically.
16. A process as claimed in claim 15, wherein the time between each interruption is in the range of from 2 to 60 minutes.
17. A process as claimed in claim 16, wherein the time between each interruption is in the range of from 5 to 30 minutes.
18. A process as claimed in any one of claims 15 to 17, wherein the duration of each interruption is in the range of from 0.1 to 15 minutes.
19. A process as claimed in claim 18, wherein the duration of each interruption is in the range of from 1 to 10 minutes.
20. A process as claimed in any one of claims 15 to 19, wherein the duration of each interruption is the same.
21. A process as claimed in any one of claims 15 to 20, wherein the time between each interruption is the same.
22. A process as claimed in any one of claims 1 to 21, wherein unreacted acetic acid and ethylene are recirculated.
23. A process as claimed in any one of claims 1 to 22, wherein the product mixture is cooled to form a condensate comprising unreacted acetic acid and ethyl acetate, the acetic acid and ethyl acetate being separated by fractional distillation.
24. A process as claimed in any one of claims 1 to 23, wherein any sulphuric acid, alkyl sulphate or alkyl hydrogen sulphate in the product mixture is recovered.
25. A process as claimed in any one of claims 1 to 24, conducted at a temperature in the range of from 130 to 1700C.
26. A process as claimed in claim 25, conducted at a temperature in the range of from 140 to 1500C.
27. A process as claimed in any one of claims 1 to 26, conducted under a pressure of up to 100 bars.
28. A process as claimed in claim 27, conducted under a pressure of from 0.5 to 10 bars.
29. A process as claimed in any one of claims 1 to 28, wherein sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate or a mixture thereof is introduced into the reaction zone.
30. A process as claimed in claim 29, wherein the concentration of sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate, or mixture thereof is in the range of from 0.1 to 2 percent by weight, based on the weight of acetic acid.
31. A process as claimed in claim 29 or claim 30, wherein the sulphuric acid, alkyl sulphate, alkyl hydrogen sulphate or mixture thereof is introduced together with the acetic acid.
32. A process as claimed in any one of claims 1 to 31, wherein the acetic acid is vapourised by introduction into the reaction zone.
33. A process as claimed in any one of
claims 1 to 31, wherein the acetic acid is vapourised in a pre-evaporator before introduction to the reaction zone.
34. A process for the manufacture of ethyl acetate, substantially as hereinbefore described in any one of the Examples.
35. A process for the manufacture of ethyl acetate by reaction of acetic acid and ethylene in the gas phase in the presence of acidic catalysts, which comprises passing ethylene over a fixed-bed catalyst with periodically alternating quantities of acetic acid at a temperature of from 130 to 170"C, the catalyst being composed of silicon dioxide having a surface from 50 to 200 m2/g and being impregnated with H2 SO4, diethylsulphate or ethylsulphuric acid or mixtures of these compounds, the acetic acid concentration calculated on ethylene varying constantly over a range from 0.01 to 40% by mole.
36. Ethyl acetate, whenever prepared by a process as claimed in any one of claims 1 to 35.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19752545845 DE2545845C3 (en) | 1975-10-14 | 1975-10-14 | Process for the preparation of ethyl acetate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1561534A true GB1561534A (en) | 1980-02-20 |
Family
ID=5959047
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB4275876A Expired GB1561534A (en) | 1975-10-14 | 1976-10-14 | Process for the manufacture of ethyl acetate |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS6017774B2 (en) |
| BE (1) | BE847271A (en) |
| BR (1) | BR7606810A (en) |
| CA (1) | CA1094101A (en) |
| CH (1) | CH602550A5 (en) |
| DE (1) | DE2545845C3 (en) |
| FR (1) | FR2327981A1 (en) |
| GB (1) | GB1561534A (en) |
| IT (1) | IT1069048B (en) |
| NL (1) | NL7611163A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0674179U (en) * | 1993-03-30 | 1994-10-21 | ケイエスケイ株式会社 | Baseball complement |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1315027A (en) * | 1959-06-08 | 1963-01-18 | Distillers Co Yeast Ltd | Process for the production of tertiary butyl acetate |
-
1975
- 1975-10-14 DE DE19752545845 patent/DE2545845C3/en not_active Expired
-
1976
- 1976-10-08 NL NL7611163A patent/NL7611163A/en not_active Application Discontinuation
- 1976-10-11 CH CH1284376A patent/CH602550A5/xx not_active IP Right Cessation
- 1976-10-12 BR BR7606810A patent/BR7606810A/en unknown
- 1976-10-12 IT IT2824476A patent/IT1069048B/en active
- 1976-10-13 CA CA263,310A patent/CA1094101A/en not_active Expired
- 1976-10-13 JP JP12196276A patent/JPS6017774B2/en not_active Expired
- 1976-10-14 FR FR7630889A patent/FR2327981A1/en active Granted
- 1976-10-14 BE BE171503A patent/BE847271A/en unknown
- 1976-10-14 GB GB4275876A patent/GB1561534A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2327981A1 (en) | 1977-05-13 |
| JPS5248617A (en) | 1977-04-18 |
| BE847271A (en) | 1977-04-14 |
| CA1094101A (en) | 1981-01-20 |
| DE2545845C3 (en) | 1979-05-23 |
| FR2327981B1 (en) | 1980-05-23 |
| DE2545845B2 (en) | 1978-09-28 |
| JPS6017774B2 (en) | 1985-05-07 |
| NL7611163A (en) | 1977-04-18 |
| CH602550A5 (en) | 1978-07-31 |
| BR7606810A (en) | 1977-08-30 |
| IT1069048B (en) | 1985-03-21 |
| DE2545845A1 (en) | 1977-04-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |