CA2071698A1 - Catalyst and process for the preparation of vinyl acetate - Google Patents
Catalyst and process for the preparation of vinyl acetateInfo
- Publication number
- CA2071698A1 CA2071698A1 CA002071698A CA2071698A CA2071698A1 CA 2071698 A1 CA2071698 A1 CA 2071698A1 CA 002071698 A CA002071698 A CA 002071698A CA 2071698 A CA2071698 A CA 2071698A CA 2071698 A1 CA2071698 A1 CA 2071698A1
- Authority
- CA
- Canada
- Prior art keywords
- catalyst
- weight
- compounds
- barium
- support
- 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.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/56—Platinum group metals
- B01J23/58—Platinum group metals with alkali- or alkaline earth metals
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C69/00—Esters of carboxylic acids; Esters of carbonic or haloformic acids
- C07C69/02—Esters of acyclic saturated monocarboxylic acids having the carboxyl group bound to an acyclic carbon atom or to hydrogen
- C07C69/12—Acetic acid esters
- C07C69/14—Acetic acid esters of monohydroxylic compounds
- C07C69/145—Acetic acid esters of monohydroxylic compounds of unsaturated alcohols
- C07C69/15—Vinyl acetate
-
- 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
- C07C67/05—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides onto unsaturated carbon-to-carbon bonds with oxidation
- C07C67/055—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides onto unsaturated carbon-to-carbon bonds with oxidation in the presence of platinum group metals or their compounds
Abstract
- ? -Abstract of the disclosure:
Catalyst and process for the preparation of vinyl acetate:
The invention relates to a process for the preparation of vinyl acetate in the gas phase from ethylene, acetic acid and oxygen or oxygen-containing gases over a catalyst, which comprises palladium and/or compounds thereof and alkali metal compounds on a support, the catalyst moreover comprising at least one barium compound, and gold, cadmium and compounds thereof being absent.
Furthermore, the invention relates to the mentioned catalyst.
Catalyst and process for the preparation of vinyl acetate:
The invention relates to a process for the preparation of vinyl acetate in the gas phase from ethylene, acetic acid and oxygen or oxygen-containing gases over a catalyst, which comprises palladium and/or compounds thereof and alkali metal compounds on a support, the catalyst moreover comprising at least one barium compound, and gold, cadmium and compounds thereof being absent.
Furthermore, the invention relates to the mentioned catalyst.
Description
~7~8 ~OECHST AKTIENGESELLSCHAFT HOE 91/F 189 Dr.MA/Dt Decription Catalyst and process for the preparation of vinyl acetate It is known that ethylene can be reacted in the gas phase S with acetic acid and oxygen or oxygen-cont3ining gases over fixed bed catalysts to give vinyl acetate. Cataly~ts for which a space-tLme yield of more than 200 g/l x h ic stated contain9 wi~hout e~ception, one of the two element combinations of palladium/cadmium~potassium or palladium/gold/potassium (US-PS 3 939 199, US-PS 4 6b8 819, EP-A-0 330 853, EP-A-0 403 950 and EP-A-0 431 478).
It has now been fou~d, surprisingly, that palladium catalysts which contain at least one barium compound and at least one alkali metal compound, but neithex ~admium nor gold nor compounds thereof, result in a space-time yield which is at le~st the same as, a combustion of ethylene to CO2 which is the same as or lower than and an ethyl acetate formation which is the same as or lower than that of the catalyst system~; mentioned of Pd/Au/K
and Pd/Cd~K. This is very advantageous, since cadmium is a disadvantage because of its toxicity and gold because of its high price, while barium is inexpensive and is non-toxic by nature, since it i5 converted immediately into barium sulfate, which is completely inert because it is sparingly soluble.
The invention accordingly relates to a process for the preparation of vinyl acetate in the gas phase from ethylene, acetic acid and oxy~en or oxygen-containing ases over a catalyst which contains palladium and/or compounds thereof and alkali metal compounds on a support, wherein the catalyst comprises at least one barium compound and in which qold and cadmium compounds thereof are absent.
- ~ ;
: . :
~: :
' , _ 2 207~
Furthermore, the inve ion relates to a catalyst which contains palladium and/or compounds thereof and alkali metal compounds on a support, wherein the catalyst comprlses at least one barium compound and in which gold and cadmium compounds thereof are absent.
The absence of ~hese elements and their compound~ means that they are pre~ent in not more than trace amounts, because of impurities in the ~tarting ~ub~tances of the 5 supported catalyst, i.e. in total concentrations of cadmium and gold of not more ~han 1 ppm, ba~ed on the total supported catalyst (support plus active components).
Suitable supports are the known inert support materials, such as silicic acid, aluminum oxide, alumosilicates, silicates, titanium oxide, zirconium oxide, titanates, ~ilicon carbide and carbon. 5ilicic acids having a specific surface area of 40 to 350 m2/g and an average pore radius of 50 to 2000 A are particularly suitable.
According to US PS 3 939 199, the total pore ~olume of a highly efficient support should be 0~4-1.2 ml/g, and less than 10~ of this volume should be formed by "micropores"
having a pore diameter of less than 30 A (Angstr~m). Such supports can be prepared from aerogenic SiO2 or an aero-genic SiO2-Al2O3 mixture, which is :in the form of vitreous microbeads, which can be produced, for example, by flame hydrolysis of silicon tetrachloride or a silicon tetra-chloride-aluminum trichloride mixture in an oxyhydrogen gas flame. These microbeads are commercially available under the name eAerosil or ~Cabosil.
EP~A-0 403 950 describes a support ~f the type ~ust mentioned, which compri~es SiO2 or an SiO2-Al2O3 mixture having a ~urface area of 50-250 m~g and a pore volume of 0.4-1.2 ml/g, the particles of which have a particle size of 4 to 9 mm, 5 to 20% of the pore volume of the support being formed by pores having radii of 200 to 3000 A and 50 to 90% of the pore volume being ormed by pores having radii of 70 to 100 A.
~7~
According to EP~A-0 431 478, shaped articles, i.e. shaped support particles, are then advantageously produced, for example by tablet-making or extrusion, from the micro-beads with the addition of one or more carbo~ylates of Li, Mg, Al, Zn, Fe or Mn as binders and with th addition of organic filler~ (such as su~ars, urea, higher fatty ~cids, longer-chain paraffins and microcrystalline cellulose) and lubricants (such a~ kaolin, graphite and metal soaps). The ~haped articles are then roasted in O2-containing gases at about 500-900~C for about 0.25-5 hours.
The catalytically ~ctive substances are applied to the ~upport ~n khe customary manner, for example by impreg-nating the support with a solution of the active substan-ces, subsequently drying it and if appropriate subjectingit to reduction. ~owever, the active substances can also be applied, for example, by precipitation on the support or by spraying on, vapour deposition or dipping.
Suitable solvents for the catalytically active substances are, above all, unsubstituted carboxylic acids having 2 to 10 carbon atoms, such as acetic acid, propionic acid, n and iso-butyric acid and the various valeric acids.
Acetic acid is preferably employed as the solvent because of its physical properties and also for economic reasons.
The additional use of an inert solvent is appropriate if the substances are not sufficiently soluble in the carboxylic acid. Palladium chloride, for example, can thus be dissolved considerably more easily in an aqueous acetic acid than in glacial acetic acid. Possible additional solvents are those which are inert and are miscible with the carboxylic acid, for example water and ether, such as tetrahydrofuran or dioxane, or hydrocarbons, such as benzene.
The catalyst support is preferably impregnated with the solution of the active components by covering the support .~
It has now been fou~d, surprisingly, that palladium catalysts which contain at least one barium compound and at least one alkali metal compound, but neithex ~admium nor gold nor compounds thereof, result in a space-time yield which is at le~st the same as, a combustion of ethylene to CO2 which is the same as or lower than and an ethyl acetate formation which is the same as or lower than that of the catalyst system~; mentioned of Pd/Au/K
and Pd/Cd~K. This is very advantageous, since cadmium is a disadvantage because of its toxicity and gold because of its high price, while barium is inexpensive and is non-toxic by nature, since it i5 converted immediately into barium sulfate, which is completely inert because it is sparingly soluble.
The invention accordingly relates to a process for the preparation of vinyl acetate in the gas phase from ethylene, acetic acid and oxy~en or oxygen-containing ases over a catalyst which contains palladium and/or compounds thereof and alkali metal compounds on a support, wherein the catalyst comprises at least one barium compound and in which qold and cadmium compounds thereof are absent.
- ~ ;
: . :
~: :
' , _ 2 207~
Furthermore, the inve ion relates to a catalyst which contains palladium and/or compounds thereof and alkali metal compounds on a support, wherein the catalyst comprlses at least one barium compound and in which gold and cadmium compounds thereof are absent.
The absence of ~hese elements and their compound~ means that they are pre~ent in not more than trace amounts, because of impurities in the ~tarting ~ub~tances of the 5 supported catalyst, i.e. in total concentrations of cadmium and gold of not more ~han 1 ppm, ba~ed on the total supported catalyst (support plus active components).
Suitable supports are the known inert support materials, such as silicic acid, aluminum oxide, alumosilicates, silicates, titanium oxide, zirconium oxide, titanates, ~ilicon carbide and carbon. 5ilicic acids having a specific surface area of 40 to 350 m2/g and an average pore radius of 50 to 2000 A are particularly suitable.
According to US PS 3 939 199, the total pore ~olume of a highly efficient support should be 0~4-1.2 ml/g, and less than 10~ of this volume should be formed by "micropores"
having a pore diameter of less than 30 A (Angstr~m). Such supports can be prepared from aerogenic SiO2 or an aero-genic SiO2-Al2O3 mixture, which is :in the form of vitreous microbeads, which can be produced, for example, by flame hydrolysis of silicon tetrachloride or a silicon tetra-chloride-aluminum trichloride mixture in an oxyhydrogen gas flame. These microbeads are commercially available under the name eAerosil or ~Cabosil.
EP~A-0 403 950 describes a support ~f the type ~ust mentioned, which compri~es SiO2 or an SiO2-Al2O3 mixture having a ~urface area of 50-250 m~g and a pore volume of 0.4-1.2 ml/g, the particles of which have a particle size of 4 to 9 mm, 5 to 20% of the pore volume of the support being formed by pores having radii of 200 to 3000 A and 50 to 90% of the pore volume being ormed by pores having radii of 70 to 100 A.
~7~
According to EP~A-0 431 478, shaped articles, i.e. shaped support particles, are then advantageously produced, for example by tablet-making or extrusion, from the micro-beads with the addition of one or more carbo~ylates of Li, Mg, Al, Zn, Fe or Mn as binders and with th addition of organic filler~ (such as su~ars, urea, higher fatty ~cids, longer-chain paraffins and microcrystalline cellulose) and lubricants (such a~ kaolin, graphite and metal soaps). The ~haped articles are then roasted in O2-containing gases at about 500-900~C for about 0.25-5 hours.
The catalytically ~ctive substances are applied to the ~upport ~n khe customary manner, for example by impreg-nating the support with a solution of the active substan-ces, subsequently drying it and if appropriate subjectingit to reduction. ~owever, the active substances can also be applied, for example, by precipitation on the support or by spraying on, vapour deposition or dipping.
Suitable solvents for the catalytically active substances are, above all, unsubstituted carboxylic acids having 2 to 10 carbon atoms, such as acetic acid, propionic acid, n and iso-butyric acid and the various valeric acids.
Acetic acid is preferably employed as the solvent because of its physical properties and also for economic reasons.
The additional use of an inert solvent is appropriate if the substances are not sufficiently soluble in the carboxylic acid. Palladium chloride, for example, can thus be dissolved considerably more easily in an aqueous acetic acid than in glacial acetic acid. Possible additional solvents are those which are inert and are miscible with the carboxylic acid, for example water and ether, such as tetrahydrofuran or dioxane, or hydrocarbons, such as benzene.
The catalyst support is preferably impregnated with the solution of the active components by covering the support .~
2 ~
material with a layer of the solution and then pouring off or filtering off the excess solution. In consider-ation of solvent losses, it is advantageous to employ only the amount of solution which corresponds to the integral pore volume of the catalyst support and to mix the components thoroughly, so that the particles of the suppoxt material are wetted uniformly. This mixing can be achieved, for example, by stirring. It is advantageous ~o carry out the Lmpregnating operation and the mixing simultaneously, for example in a rotary drum or a tumble dryer, in which case drying can follow immediately. It is furthermore advantageous to choose the composition of the solution used to impregnate the catalyst æupport such that the desired amount of active substances is applied by a single impregnation. However, it can also be applied by several impregnation steps.
The catalyst support impregnated with this solution is preferably dried under reduced pressure. The temperature during drying should be less than 120C, preferably less than 90C. It is furthermore in general advisable to carry out the drying in a stream of inert gas, for example in a stream of nitrogen or carbon dioxide. The residual solvent content after drying should preferably be less than 8% by weight, in particular less than 6~ by weight.
The catalyst contains palladium and/or compounds thereof as the noble metal component.
Possible compounds of palladium are all the salts and complexes which are soluble (and if appropriate reducible) and do not leave behind any deactivating substances, such as halogen or sulfur, in the finished catalyst ~washed with water if necessary). The carboxy-lates, preferably the salts of aliphatic monocarboxylic acids having 2 to 5 carbon atoms, for ex~mple the acetate, the propionate or the butyrate, are particularly , : ', - .
2~7~6~8 suitable. The nitrate, nitrite, hydrated oxide, oxalate, acetylacetonate and acetoacetate, for example, are furthermore suitable. Palladium acetate is the particu-larly preferred palladium compound because of its solu-bility and its accessibility.
The content of palladium in the catalyst is in general 0.3-3~ by weight, preferably 1.5 to 2.5% by weight, in particular 2-2.5% by weight.
The catalyst contains as activators at least one barium compound, preferably a carboxylate, such as the formate, aceta~e, propionate or butyrate. At least one alkali metal compound, preferably at least one K, Rb or Cs compound, in particular at least one R compound, is furthermore pre~ent. Carboxylates above all are suitable as the alka:Li metal compounds, in particular the acetates and propionates.
Suitable barium and alkali metal compounds are also those which are converted into the acetate under the reaction conditions, such as, for example, hydroxides~ oxides and carbonates.
The content of barium in the catalyst is in general 0.1-10~ by weight, preferably 0.2-4~ by weight, in particular 0.4-3% by weight. The content of alkali metal elements is in general 0.3-10% by weight, preferably 0.5-8% by weight, in particular 1-4% by weight. The percentage figures stated always relate to the amounts of the elements palladium, barium and alkali metal pre~ent in the catalyst, based on the total weight of ~he catalyst;
any anions are not included in the calculation.
If a reduction is carried out on the palladium compound, which can sometimes be beneficial, ~his can be carried out in vacuo, under normal pressure or under an increased pressure of up to 10 bar. It is advisable here to dilute - 6 - 2~7~
the reducing agen~ with an inert gas to a higher degree, the higher the pressure. The reduction temperature is in general between 40 and 260C, preferably between 70 and 200C. It is in general advantageous to use for the S reduction an inert gas/reducing agent mixture which contains O.Ql to 50% by volume, preferably 0.5 to 20~ by volume, of reducing agent. Nitrogen, carbon dioxide or a noble gas, for example, can be used as the inert gas.
Examples of possible reducing agents are hydrogen, methanol, formaldehyde, ethylene, propylene, isobutylene, butylene and other olefins. The amount of reducing agent depends on the amount of palladium; the reduction equiva-lent should in ~eneral be at least 1 to 1.5 times the oxidation equivalent, but larger amount~ of reducing agent do no harm. The reduction can be carried out after the drying, in thP same unit.
The vinyl acetate is in general prepared by passing acetic acid, ethylene and o~ygen or oxygen-containing gases over the finished catalyst at temperatures of 100 to 220C, preferably 120 to 200C, under pressures of 1 to 25 bar, preferably 1 to 20 bar, it being possibe for unreacted components to be passed in circulation. The oxygen concentration i8 advantageously kept below 10~ by volume (based on the acetic acid-free gas mixture). Under certain circum~tances, however, it is also advantageous to dilute the mixture with inert gases, such as nitrogen or carbon dioxide. CO2 is particularly suitable for the dilution in circulation proce~ses, since it is formed in small amounts during the reaction.
The following examples are intended to illustrate the invention. The percentage data of the elements Pd, Ba and are percentages by weight.
Comparison Example 1 100 g of silicic acid tablets which had been produced from aerogenic SiO2 microbeads having a surface area of ~ ' ~ `: '. . ' :
- i~
: . , ~7~ 6~
200 m2/g by pressing with Mg stearate as the binder and subsequent roasting in accordance with EP-A-0 431 478, were impregnated with a solution of 5.6 g of Pd acetate, S.l g of Cd acetate and 5.5 g of K acetate in 78~5 ml of glacial acetic acid and dried. The finished catalyst contained 2.3% of Pd, 1.8% of Cd and 1.9% of X, based on the system consisting of salts and support.
50 ml of the finishQd catalyst were introduced into a reaction tube having an internal diameter of 8 mm and a length of 1.5 m. The gas to be reacted was then passed over the catalyst under a pressur0 of 8 bar (reactor intake) at a catalyst temperature of 150C. This gas consisted of 27% by volume of ethylene, 55~ by volume of N2, 12% by volume of acetic acid and 6% by volume Of 2 at the reactor intake. The results can be seen from the table.
Comparison Example 2 The procedure was as in Comparison Example 1, with the exception that Al stearate instead of Mg stearate was used as the binder. Testing uncler the conditions of Comparison Example 1 gave the values shown in the table.
Example 1 100 g of the support mentioned in Comparison Example 1 were impregnated with a solution of 5.6 g of Pd acetate, 5.3 g of Ba acetate and 5.5 g of K acetate in 78.5 ml of glacial acetic acid and dried. The finished catalyst contained 2.3% of Pd, 2.2% of Ba and 1.9% of K, based on the system consisting of support and salts. The values shown in the table resulted under the conditions of Comparison Example 1.
Example 2 The support used in Comparison Example 1 was Lmpregnated with a solution of 5.6 g of Pd acetate, 1.1 g of Ba acetate and 5.5 g of K acetate in 78.5 ml of glacial ,~ .
.
2 ~
acetic acid and dried. The finished catalyst contained 2.3% of Pd, 0.5% of Ba and 1.9% of K, based on the system consis$ing of support and salt~. ~he ~alues achieved under the conditions of Comparison Example 1 are shown in the table.
Table . _ Comparison Example Example STY (g/l x h) 838 ~ 840 ~. _ Combustion (%) 5.4 4.6 6 4 Ethyl acetate content (ppm) 190 218 20 80 "STY" denote the space-tLme yield; ~combusion (~)"
denotes the percentage of ethy.lene reacted which is converted into COa; "ethyl acetate content~ relates to the content of ethyl acetate in the condensed p~rt of the reaction product.
., . ~ . .
material with a layer of the solution and then pouring off or filtering off the excess solution. In consider-ation of solvent losses, it is advantageous to employ only the amount of solution which corresponds to the integral pore volume of the catalyst support and to mix the components thoroughly, so that the particles of the suppoxt material are wetted uniformly. This mixing can be achieved, for example, by stirring. It is advantageous ~o carry out the Lmpregnating operation and the mixing simultaneously, for example in a rotary drum or a tumble dryer, in which case drying can follow immediately. It is furthermore advantageous to choose the composition of the solution used to impregnate the catalyst æupport such that the desired amount of active substances is applied by a single impregnation. However, it can also be applied by several impregnation steps.
The catalyst support impregnated with this solution is preferably dried under reduced pressure. The temperature during drying should be less than 120C, preferably less than 90C. It is furthermore in general advisable to carry out the drying in a stream of inert gas, for example in a stream of nitrogen or carbon dioxide. The residual solvent content after drying should preferably be less than 8% by weight, in particular less than 6~ by weight.
The catalyst contains palladium and/or compounds thereof as the noble metal component.
Possible compounds of palladium are all the salts and complexes which are soluble (and if appropriate reducible) and do not leave behind any deactivating substances, such as halogen or sulfur, in the finished catalyst ~washed with water if necessary). The carboxy-lates, preferably the salts of aliphatic monocarboxylic acids having 2 to 5 carbon atoms, for ex~mple the acetate, the propionate or the butyrate, are particularly , : ', - .
2~7~6~8 suitable. The nitrate, nitrite, hydrated oxide, oxalate, acetylacetonate and acetoacetate, for example, are furthermore suitable. Palladium acetate is the particu-larly preferred palladium compound because of its solu-bility and its accessibility.
The content of palladium in the catalyst is in general 0.3-3~ by weight, preferably 1.5 to 2.5% by weight, in particular 2-2.5% by weight.
The catalyst contains as activators at least one barium compound, preferably a carboxylate, such as the formate, aceta~e, propionate or butyrate. At least one alkali metal compound, preferably at least one K, Rb or Cs compound, in particular at least one R compound, is furthermore pre~ent. Carboxylates above all are suitable as the alka:Li metal compounds, in particular the acetates and propionates.
Suitable barium and alkali metal compounds are also those which are converted into the acetate under the reaction conditions, such as, for example, hydroxides~ oxides and carbonates.
The content of barium in the catalyst is in general 0.1-10~ by weight, preferably 0.2-4~ by weight, in particular 0.4-3% by weight. The content of alkali metal elements is in general 0.3-10% by weight, preferably 0.5-8% by weight, in particular 1-4% by weight. The percentage figures stated always relate to the amounts of the elements palladium, barium and alkali metal pre~ent in the catalyst, based on the total weight of ~he catalyst;
any anions are not included in the calculation.
If a reduction is carried out on the palladium compound, which can sometimes be beneficial, ~his can be carried out in vacuo, under normal pressure or under an increased pressure of up to 10 bar. It is advisable here to dilute - 6 - 2~7~
the reducing agen~ with an inert gas to a higher degree, the higher the pressure. The reduction temperature is in general between 40 and 260C, preferably between 70 and 200C. It is in general advantageous to use for the S reduction an inert gas/reducing agent mixture which contains O.Ql to 50% by volume, preferably 0.5 to 20~ by volume, of reducing agent. Nitrogen, carbon dioxide or a noble gas, for example, can be used as the inert gas.
Examples of possible reducing agents are hydrogen, methanol, formaldehyde, ethylene, propylene, isobutylene, butylene and other olefins. The amount of reducing agent depends on the amount of palladium; the reduction equiva-lent should in ~eneral be at least 1 to 1.5 times the oxidation equivalent, but larger amount~ of reducing agent do no harm. The reduction can be carried out after the drying, in thP same unit.
The vinyl acetate is in general prepared by passing acetic acid, ethylene and o~ygen or oxygen-containing gases over the finished catalyst at temperatures of 100 to 220C, preferably 120 to 200C, under pressures of 1 to 25 bar, preferably 1 to 20 bar, it being possibe for unreacted components to be passed in circulation. The oxygen concentration i8 advantageously kept below 10~ by volume (based on the acetic acid-free gas mixture). Under certain circum~tances, however, it is also advantageous to dilute the mixture with inert gases, such as nitrogen or carbon dioxide. CO2 is particularly suitable for the dilution in circulation proce~ses, since it is formed in small amounts during the reaction.
The following examples are intended to illustrate the invention. The percentage data of the elements Pd, Ba and are percentages by weight.
Comparison Example 1 100 g of silicic acid tablets which had been produced from aerogenic SiO2 microbeads having a surface area of ~ ' ~ `: '. . ' :
- i~
: . , ~7~ 6~
200 m2/g by pressing with Mg stearate as the binder and subsequent roasting in accordance with EP-A-0 431 478, were impregnated with a solution of 5.6 g of Pd acetate, S.l g of Cd acetate and 5.5 g of K acetate in 78~5 ml of glacial acetic acid and dried. The finished catalyst contained 2.3% of Pd, 1.8% of Cd and 1.9% of X, based on the system consisting of salts and support.
50 ml of the finishQd catalyst were introduced into a reaction tube having an internal diameter of 8 mm and a length of 1.5 m. The gas to be reacted was then passed over the catalyst under a pressur0 of 8 bar (reactor intake) at a catalyst temperature of 150C. This gas consisted of 27% by volume of ethylene, 55~ by volume of N2, 12% by volume of acetic acid and 6% by volume Of 2 at the reactor intake. The results can be seen from the table.
Comparison Example 2 The procedure was as in Comparison Example 1, with the exception that Al stearate instead of Mg stearate was used as the binder. Testing uncler the conditions of Comparison Example 1 gave the values shown in the table.
Example 1 100 g of the support mentioned in Comparison Example 1 were impregnated with a solution of 5.6 g of Pd acetate, 5.3 g of Ba acetate and 5.5 g of K acetate in 78.5 ml of glacial acetic acid and dried. The finished catalyst contained 2.3% of Pd, 2.2% of Ba and 1.9% of K, based on the system consisting of support and salts. The values shown in the table resulted under the conditions of Comparison Example 1.
Example 2 The support used in Comparison Example 1 was Lmpregnated with a solution of 5.6 g of Pd acetate, 1.1 g of Ba acetate and 5.5 g of K acetate in 78.5 ml of glacial ,~ .
.
2 ~
acetic acid and dried. The finished catalyst contained 2.3% of Pd, 0.5% of Ba and 1.9% of K, based on the system consis$ing of support and salt~. ~he ~alues achieved under the conditions of Comparison Example 1 are shown in the table.
Table . _ Comparison Example Example STY (g/l x h) 838 ~ 840 ~. _ Combustion (%) 5.4 4.6 6 4 Ethyl acetate content (ppm) 190 218 20 80 "STY" denote the space-tLme yield; ~combusion (~)"
denotes the percentage of ethy.lene reacted which is converted into COa; "ethyl acetate content~ relates to the content of ethyl acetate in the condensed p~rt of the reaction product.
., . ~ . .
Claims (8)
1. A process for the preparation of vinyl acetate in the gas phase from ethylene, acetic acid and oxygen or oxygen-containing gases over a catalyst which contains palladium and/or compounds thereof and alkali metal compounds on a support, wherein the catalyst comprises at least one barium compound and in which gold and cadmium and compounds thereof are absent.
2. The process as claimed in claim 1, wherein the catalyst comprises at least one potassium compound.
3. The process as claimed in claim 1 or 2, wherein the catalyst comprises 0.1 % by weight to 10 % by weight of barium, based on the total weight of the catalyst.
4. The process as claimed in one of claims 1 to 3, wherein the catalyst comprises 0.2 % by weight to 4 % by weight of barium, based on the total weight of the catalyst.
5. Catalyst which contains palladium and/or compounds thereof and alkali metal compounds on a support, wherein the catalyst comprises at least one barium compound and in which gold and cadmium and compounds thereof are absent.
6. Catalyst as claimed in claim 5, which comprises at least one potassium compound.
7. Catalyst as claimed in claim 5 or 6, which comprises 0.1 % by weight to 10 % by weight of barium, based on the total weight of the catalyst.
8. Catalyst as claimed in claim 5 or 6, which comprises 0.2 % by weight to 4 % by weight of barium, based on the total weight of the catalyst.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4120491.3 | 1991-06-21 | ||
| DE4120491 | 1991-06-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2071698A1 true CA2071698A1 (en) | 1992-12-22 |
Family
ID=6434436
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002071698A Abandoned CA2071698A1 (en) | 1991-06-21 | 1992-06-19 | Catalyst and process for the preparation of vinyl acetate |
Country Status (12)
| Country | Link |
|---|---|
| EP (1) | EP0519436A1 (en) |
| JP (1) | JPH05186393A (en) |
| KR (1) | KR930000463A (en) |
| CN (1) | CN1068104A (en) |
| AU (1) | AU1835392A (en) |
| BG (1) | BG96466A (en) |
| BR (1) | BR9202324A (en) |
| CA (1) | CA2071698A1 (en) |
| CZ (1) | CZ190492A3 (en) |
| MX (1) | MX9203015A (en) |
| PL (1) | PL294868A1 (en) |
| TW (1) | TW213869B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5567839A (en) * | 1993-11-19 | 1996-10-22 | Bp Chemicals Limited | Process for the preparation of vinyl acetate |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4323981C1 (en) * | 1993-07-16 | 1995-03-09 | Hoechst Ag | Pallet and potassium, and cadmium, barium or gold-containing coated catalyst, process for its preparation and its use in the production of vinyl acetate |
| DE4323980C1 (en) * | 1993-07-16 | 1995-03-30 | Hoechst Ag | Pallet and potassium, and cadmium, barium or gold-containing coated catalyst, process for its preparation and its use in the production of vinyl acetate |
| DE4323978C1 (en) * | 1993-07-16 | 1995-02-16 | Hoechst Ag | Pallet and potassium, and cadmium, barium or gold-containing coated catalyst, process for its preparation and its use in the production of vinyl acetate |
| DE69514283T3 (en) * | 1994-06-09 | 2008-01-24 | Institut Français du Pétrole | Process for the catalytic hydrogenation and in this process for the catalyst to be used |
| FR2720957B1 (en) * | 1994-06-09 | 1996-08-30 | Inst Francais Du Petrole | Hydrogenation catalyst containing palladium and at least one alkaline or alkaline earth metal and hydrogenation process using this catalyst. |
| DE19613791C2 (en) * | 1996-04-04 | 2002-01-31 | Celanese Chem Europe Gmbh | Catalyst, process for its production and process for the production of vinyl acetate |
| US5859287A (en) * | 1997-10-30 | 1999-01-12 | Celanese International Corporation | Process for preparing vinyl acetate utilizing a catalyst comprising palladium, gold, and any of certain third metals |
| DE19755023C2 (en) * | 1997-12-11 | 2000-03-09 | Celanese Chem Europe Gmbh | Catalyst and process for making vinyl acetate |
| US6072078A (en) * | 1997-12-12 | 2000-06-06 | Celanese International Corporation | Vinyl acetate production using a catalyst comprising palladium, gold, copper and any of certain fourth metals |
| CN1109578C (en) * | 1999-05-26 | 2003-05-28 | 冯士光 | Catalyst for treating vehicle exhaust gas, catalyzing granules and purifier using the same catalyst |
| SG101929A1 (en) * | 1999-12-29 | 2004-02-27 | Dairen Chemical Corp | Catalyst for oxacylation and use of the same |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA954875A (en) * | 1963-09-12 | 1974-09-17 | National Distillers And Chemical Corporation | Catalyst activation in process for preparing esters |
| FR1546361A (en) * | 1967-04-29 | 1968-11-15 | Sir Soc Italiana Resine Spa | Process for the preparation of unsaturated esters |
| ES362221A1 (en) * | 1967-12-28 | 1970-12-01 | Nat Distillers Chem Corp | Preparation of unsaturated esters |
| JPS4837245B1 (en) * | 1969-10-02 | 1973-11-09 | ||
| US3939199A (en) * | 1971-01-06 | 1976-02-17 | Hoechst Aktiengesellschaft | Oxacylation of olefins in the gaseous phase |
| JPS5917098B2 (en) * | 1979-01-17 | 1984-04-19 | ジェイエスアール株式会社 | Method for producing conjugated diene monoester |
| US4550097A (en) * | 1984-08-20 | 1985-10-29 | Phillips Petroleum Company | Catalyst for the production of allyl acetate |
-
1992
- 1992-06-01 TW TW081104277A patent/TW213869B/zh active
- 1992-06-11 PL PL29486892A patent/PL294868A1/en unknown
- 1992-06-15 BG BG96466A patent/BG96466A/en unknown
- 1992-06-17 EP EP92110247A patent/EP0519436A1/en not_active Withdrawn
- 1992-06-19 MX MX9203015A patent/MX9203015A/en unknown
- 1992-06-19 JP JP4161359A patent/JPH05186393A/en not_active Withdrawn
- 1992-06-19 CA CA002071698A patent/CA2071698A1/en not_active Abandoned
- 1992-06-19 BR BR929202324A patent/BR9202324A/en not_active Application Discontinuation
- 1992-06-19 CZ CS921904A patent/CZ190492A3/en unknown
- 1992-06-19 KR KR1019920010650A patent/KR930000463A/en not_active Application Discontinuation
- 1992-06-19 AU AU18353/92A patent/AU1835392A/en not_active Abandoned
- 1992-06-20 CN CN92104828A patent/CN1068104A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5567839A (en) * | 1993-11-19 | 1996-10-22 | Bp Chemicals Limited | Process for the preparation of vinyl acetate |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0519436A1 (en) | 1992-12-23 |
| MX9203015A (en) | 1992-12-01 |
| PL294868A1 (en) | 1993-02-22 |
| BG96466A (en) | 1994-03-31 |
| BR9202324A (en) | 1993-01-19 |
| AU1835392A (en) | 1993-03-11 |
| CN1068104A (en) | 1993-01-20 |
| KR930000463A (en) | 1993-01-15 |
| CZ190492A3 (en) | 1993-01-13 |
| TW213869B (en) | 1993-10-01 |
| JPH05186393A (en) | 1993-07-27 |
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