Media epoxidation catalyst, its preparation and use

 

The carrier has speed solubilize the sodium, defined by the amount of sodium released by immersing the carrier in boiling water at a ratio of boiling water and media 3:1 (wt./wt.), not more than 5 wt.h. per million, based on the total weight of the carrier, for 5 minutes When this method of preparation of the catalyst lies in the fact that the rate of solubilization of the sodium reaching method, effective for transfer of an ionisable particles on the surface of the medium in the ionic state, and removing at least part of these particles, or transfer of an ionisable particles in the insoluble state, or transfer of an ionisable particles in a stationary state. The catalyst contains said media, silver and optional promoter. The catalyst was prepared by impregnation, where the activity of hydrogen ions in the solution is reduced by adding a base. In addition, the claimed method for the catalytic epoxidation of alkene oxygen-containing gas. Stated media controlled by the rate of solubilization provide catalysts with improved catalytic properties, such as activity, selectivity and activity and/or characteristic selectivity over time. the with improved catalytic properties, in particular to a catalyst suitable for the production of epoxides.

The background to the invention Described ways to reduce the total concentration of soluble particles in the mass of the catalyst carrier. Typically, these methods include the process by which this carrier is made thus to reduce the concentration of such particles in the mass media. These approaches limit the composition of the media, often with undesirable effects such as high density media.

In U.S. patent 4797270 described washing water to reduce the content of sodium in the powdered aluminum oxide. For the extraction of other metals may require the establishment pH of wash water, and in Japanese patent JP56164013 described the use of low pH (acid) for the extraction of uranium and thorium from raw materials is calcined-aluminum oxide.

In U.S. patent 4361504 and 4366092 offered to wash the catalyst for ethylene oxide with water after application to the carrier of the silver or silver/gold. In European patent application EP-211521 described washing of the catalyst with hot water to remove the main substances remaining on the catalyst in the process of impregnation with silver, or coercion is impregnated carrier is immersed in an inert, not miscible with water, an organic solvent containing dissolved aliphatic amine. In U.S. patent 4810689 described the application of silver compounds, decomposition of this compound silver to silver in the presence of compounds of alkali metal, removal of organic deposits by washing and the introduction of fresh alkali metal by impregnation during or after the stage of washing. In U.S. patent 4186106 and 4125480 described washing with an inert fluid after application of catalytic metal and before application of the promoting agent.

In U.S. patent 4994587 described method of epoxidation of alkene comprising contacting the alkene with oxygen-containing gas in the presence of at least one efficiency-enhancing gaseous member of a pair of redox half-reactions selected from the group consisting of NO, NO2N2O3and N2O4and the solid catalyst, and the catalyst contains silver and at least one efficiency-enhancing nitrate salt of a member of a pair of redox half-reactions, on the media of solid alpha-alumina containing less than about 50 hours per million (ppm), and preferably IU the relatively low content of sodium and certain redox reaction pair, claiming that in other cases, the presence of leachable sodium in a silver catalyst improves the efficiency of the system commonly used in the epoxidation conditions.

In the preceding technical field the interest has been focused on the total number of impurities, i.e. impurities in the entire mass. Unfortunately, the method of removal of impurities, usually pointed to the impact on the device itself. Currently, it is found that controlling the rate of solubilization of some particles, in particular sodium, on the surface of the medium, leads to a catalyst with improved catalytic properties.

A brief description of the invention In accordance with the present invention presents a catalyst carrier with a speed solubilize the sodium, measured by the number allocated when immersed in 3: 1 (mass/mass) of boiling water, which constitutes not more than 5 wt.h. per million, based on the total weight of the carrier, for 5 minutes

The following method embodiment of the invention presents a method of obtaining mentioned catalyst carrier in which the said speed solubilize the sodium reaches way that is efficient for translation inisheer particles on the carrier surface, ion sanie, or transfer inisheer particles in the stationary state.

The following method embodiment of the invention presents a catalyst, particularly a catalyst suitable for the epoxidation of olefins in the gas phase, and the catalyst contains said media and one or more catalytically active metals, and optionally one or more applied thereto promoting substances.

Detailed description of the invention it has Been found that the media is controlled by the rate of solubilization, particularly with controlled speed solubilize the sodium and/or soluble silicate, provide catalysts with improved catalytic properties, such as activity, selectivity and activity and/or characteristic selectivity over time. I believe that the speed control solubilization improves the properties of most catalysts, regardless of how much of the impurities contained in the material mass media. In addition, the regulation of the rate of solubilization will be performed for organic or inorganic carriers.

The usual media of the invention has a speed solubilize the sodium in boiling water, which govern so caemi speed solubilize the sodium in the solvent after placing in the solvent medium at a certain time and when the ratio of the boiling solvent and carrier, equal to 3:1. Thus, the rate of solubilization in boiling water 5 wt.h. per million sodium/5 min represents the amount of sodium that is defined in the water after the media was in boiling water for 5 minutes

Typically, the carriers are inorganic substances, such as compounds based on aluminum oxide, silicon dioxide, or titanium dioxide, or their combinations, such as a native oxide of aluminum-silicon oxide. The media can also be obtained from compounds based on carbon, such as charcoal, activated carbon or fullerenes.

Ionithermie particles, usually located on the native inorganic type include sodium, potassium, aluminates, soluble silicate, calcium, magnesium, silicate, and combinations thereof. Of particular interest Ionithermie anionic particles on the surface, in particular Ionithermie silicates. The rate of solubilization of the silicates may be determined by the method of inductively coupled plasma (ICP), and the number of silicon particles on the surface can be determined using x-ray photoelectron spectroscopy (RFS). However, since sodium is soluble in the same solvents in which soluble silicates, skorea as an indicator to determine the present invention. Another detection method is to measure the conductivity of the solution processing.

As used here, the "surface" of the media represents the area of the carrier which can be measured in the standard way of Brunauer, Emmett and teller (Brunauer, Emmett and Teller, B. E. T.). More precisely, the surface of the carrier represents the area on which the reaction occurs. It was found that the decrease in the concentration inisheer particles on the surface of the medium is effective and efficient from the standpoint of cost way of achieving the desired speed solubilize the sodium on the surface. "Insueta" particle is a particle that can be translated in the ionic state, while the term "ion" or "ion" refers to an electrically charged chemical group.

Reducing the rate of surface solubilize inisheer particles can be accomplished by any method effective to (i) transfer inisheer particles in the ionic state and the removal of these particles, or (ii) transfer inisheer particles in the insoluble state, or (iii) transfer inisheer particles in a stationary state. However, the use of aggressive media undesirable because these environments tend to dissolve n is islote, which are considered aggressive environments, remove the cations from the media, but they are quite ineffective for removing unwanted anions, such as silicates. Effective ways to reduce concentrations include washing media; ion exchange; evaporation, precipitation or binding of impurities in the industry; carry out reaction for translation inisheer particles on the surface in the insoluble state; their combination. You can process a mass media or process used to obtain the carrier of the raw materials before receiving media. Even greater improvements in controlling the rate of solubilization is observed when processing as raw material for the media, and the finished media.

For obtaining of the catalyst carrier, the carrier usually impregnate compound(s), complex(mi) and/or salt(salts) of the metal dissolved in a suitable solvent, is effective for coating or impregnation of the carrier of a catalytically effective amount of metal. As used here, "catalytically effective amount" means the amount of metal that will provide measurable catalytic effect. For example, in relation to the catalyst for the epoxidation of olefins catalytically effective amount IU is in the oxide alkylene. In addition, either before or at the same time or after the application of the catalytically active metal on the carrier, you can also apply one or more promoters. Used here, the term "promoter" refers to a component that is effective, ensuring the improvement of one or more catalytic properties of the catalyst compared to a catalyst not containing such a component.

To further improve the properties of the catalyst are observed in the case when the coating metal is carried out at the contact of the carrier with a solution for impregnation, the activity of hydrogen ions which are reduced. "The activity of hydrogen ions", as used here, represents the activity of hydrogen ions, as measured by the potential of the hydrogen ion-selective electrode. As used here, the solution with "low" activity of hydrogen ions refers to the solution, the activity of hydrogen ions which is changed by adding the base so that the activity of hydrogen ions this modified solution is reduced in comparison with the activity of hydrogen ions in the same solution in an unmodified state. The basis chosen for changes of the solution, you can choose from any of the base or connection with the PKbless Tav solution for impregnation, that is, which does not change the desired metal concentration in the solution used for impregnation and supported on a carrier. Will not change the concentration of metals in the solution used for impregnation of an organic base, examples of which include hydroxides of tetraalkylammonium and 1,8-bis(dimethylamino)naphthalene. If the change in the concentration of metals in solution for impregnation is not important, you can use the metal hydroxides.

In that case, when the solution for impregnation is at least partially water, indicating the change in the activity of hydrogen ions can be determined by using pH meter, knowing that the resulting measurement is not pH within the true water determination. "Measured pH" as used here, will mean a similar pH non-aqueous system using a standard pH probe. Effective even small changes in the "measured pH" compared with the initial solution for impregnation, and improved catalytic properties continue increasing change "measured pH" adding base. Apparently, adding a large number of reasons not adversely affect the operation of the catalyst; however, it was observed that the addition of a large Colchester. In the case when the addition of the base is too small, the activity of hydrogen ions will not be affected. The procedure of reduction of the activity of hydrogen ions is also very effective when used by itself, that is, when the impregnation does not reduce the concentration inisheer particles.

The impregnated carrier, also known as the precursor of the catalyst is dried in the presence of the atmosphere, which also restores the catalytic metal. Known in the art drying methods include steam drying, drying in an atmosphere with a controlled oxygen concentration, drying in reducing atmosphere, drying in air and stepwise drying using an appropriate linear or stepwise the temperature curve. By means of example the invention will be described in more detail for a catalyst suitable for the production of epoxides in the gas phase, also known as the catalyst for the epoxidation.

The epoxidation catalyst typically contains inorganic media (for example, on the basis of aluminum oxide, such as-aluminium oxide, deposited on the carrier by one or more catalytically active metals. On aluminum usually contains particles, includes sodium, potassium, aluminates, soluble silicates, calcium, magnesium, silicates and combinations thereof. It was found that silicates and some other anions are particularly undesirable Ionithermie particles in the catalyst for the epoxidation.

In accordance with the invention, the rate of solubilization of sodium in 3:1 (wt. /Mac. ) boiling water adjust to a value less 5 wt.h. per million Na/5 min. Speed solubilization can be adjusted by reducing the concentration inisheer particles on the surface, as described above.

Media with variable speed solubilization impregnated with metal ions or compound(s), complex(mi) and/or salt(salt) dissolved in a suitable solvent sufficient to cause the desired application to the media. If the applied substance is silver, the usual application is from 1 to 40 wt.%, preferably from 1 to 30 wt.%, silver based on the weight of the entire catalyst. Then the impregnated carrier is separated from the solution and deposited compound of the metal(minerals) reduced to metallic silver.

You can apply one or more promoters, either before or at the same time, or after application of the metal. Promoters for catalitically metals and their combinations. The promoting substance, usually a compound(s) and/or salt(salts) promoter, dissolved in a suitable solvent.

For oxide catalysts for the epoxidation of olefins metals of group IA usually chosen from potassium, rubidium, cesium, lithium, sodium, and combinations thereof; preferred are potassium and/or cesium and/or rubidium. Even more preferred is a combination of cesium and at least one additional metal of group IA, such as cesium and potassium, cesium and rubidium or cesium, and lithium. The metals of group IIA usually chosen from magnesium, calcium, strontium, barium and combinations thereof, transition metals of group VIII are usually chosen from cobalt, iron, Nickel, ruthenium, rhodium, palladium, and combinations thereof, and rare earth metals are usually chosen from lanthanum, cerium, neodymium, samarium, gadolinium, dysprosium, erbium, ytterbium and mixtures thereof. Non-limiting examples of other promoters include perrenate, sulfate, molybdate, tungstate, chromate, phosphate, borate, sulfate anion, fluoride anion, oxy-anions of groups IIIB through VIB, oxy-anions of an element selected from groups III no VIIB, alkali metal salt with halide anions and oxy-anions selected from groups IIIA VIIA and IIIB in VIIB. The number of promoter IU the present catalyst, and the metal of group VIIb less than 3,600 hours per million, expressed as metal, by weight of the total catalyst.

To further improve the catalytic properties of the activity of hydrogen ions solution for impregnation reduce, for example, adding the base. The usual solution for impregnation in the beginning is pretty basic, so to further reduce the activity of hydrogen ions using a strong base. Examples of strong bases include hydroxide of alkylamine, such as the hydroxide of tetraethylammonium, lithium hydroxide and cesium hydroxide. To maintain the desired composition of the impregnating solution and download metal prefer organic base, such as hydroxide of tetraethylammonium. Adding bases in such systems, as a rule, leads to change "measured pH", amounting to approximately 3, realizing that the "measured pH" is not true pH, because the system for water treatment is not.

The media used in these catalysts, in its broadest aspects may be any of a large number of conventional porous refractory carrier catalysts, or substances of media that are considered to be relatively inert. Such common substances known special is of epoxidation catalysts preferably are of a macroporous structure and surface area, less approximately 10 m2/g, and preferably less approximately 3 m2/, Examples of carriers for different catalysts are the oxides of aluminum (including substance sold under the trade name "Alundum"), charcoal, pumice, magnesia, Zirconia, diatomaceous earth, fuller earth, silicon carbide, porous agglomerates containing silicon dioxide and/or silicon carbide, silicon dioxide, magnesium oxide, some clay, synthetic or natural zeolites, alkaline earth carbonates and ceramics. Refractory carriers, particularly useful for the preparation of catalysts for the epoxidation of olefins include aluminous substances, in particular, those which contain-aluminum oxide. In the case of media containing-aluminum oxide, is preferred as the specific surface of which is defined by the method of B. E. T., ranges from 0.03 to 10 m2/g, preferably from 0.05 to 5 m2/g, more preferably from 0.1 to 3 m2/g and a water pore volume, specific conventional method of water absorption is 0.1 to 0.75 ml/g volume. Method B. E. T. the determination of the specific surface detail Brunauer, S., Emmett, P. Y. and E. Teller, J. Am. Chem. So occhialini. These carriers from-aluminium oxide have relatively uniform pore diameters and are more fully characterized by the fact that they have a specific surface area by B. E. I. from 0.1 to 3 m2/g, preferably from 0.1 to 2 m2/g and a water volume of pores of from 0.10 to about 0,55 ml/year In the number of producers of these media is part of Norton Chemical Process Products Corporation and United Catalysts, Inc. (UCI).

Just described is obtained epoxidation catalysts used for gas-phase production of epoxides, in particular ethylene oxide. The usual method of epoxidation involves loading of the catalysts in the reactor. Designed for the conversion of raw material, usually a mixture of ethylene, oxygen, carbon dioxide, nitrogen and ethyl chloride, is passed over the catalyst bed at elevated pressure and temperature. The catalyst converts raw materials into the output stream of a product containing ethylene oxide. To improve the performance of the conversion of the catalyst to catalyst can also add oxides of nitrogen (NOx).

The following examples illustrate the invention.

EXAMPLES of the Media In table I are given the media used for examples.

The wash procedure of carrier water for sample 1, 2, 3, 4, 6, 7, 12.

PTEM media were removed and placed in 300 g of fresh boiling water for another 15 minutes This procedure was repeated once more, a total of three dives; at this point the medium was separated from water and dried in a ventilated oven at 150oC for 18 hours. After that, the dried carrier used for the preparation of the catalyst by the way, the main provisions of which are described in the following examples.

The solution for impregnation of the Raw material solution containing a silver-amine-oxalate was prepared by the following procedure: 415 g of chemically pure sodium hydroxide dissolved in 2340 ml of deionized water and brought the temperature up to 50oC.

1699 g of silver nitrate high purity "Spectropure" was dissolved in 2100 ml of deionized water and brought the temperature up to 50oC.

To the silver nitrate solution slowly, with stirring, was added a solution of sodium hydroxide, maintaining the temperature of the solution at 50oC. the Mixture was stirred 15 min, then the temperature was lowered to 40oC.

From the precipitate, formed during mixing, removed the water and measured the conductivity of water containing sodium ions and nitrate ions. To a solution of silver newly added volume of fresh deionized water equal to the withdrawn volume. The solution was stirred 15 min at 40oC. This procedure was repeated up until the conductivity of the 1500 ml of fresh deionized water.

Added 630 g of dihydrate of oxalic acid of high purity by increments of approximately 100, the Temperature was maintained at 40oC, and the pH was maintained above 7.8.

From this mixture were removed water, having a containing silver suspension of high concentration. Cooled slurry of silver oxalate 30oC.

Added 699 g of 92 wt.%, Ethylenediamine (8% deionized water), keeping the temperature not exceeding 30oC. the resulting solution contained approximately 27-33 wt.% silver.

To this solution was added a sufficient amount of 45 wt.% water sO and water, having a final catalyst containing a 14.5 wt.% silver and the desired loading of cesium (see examples).

The method of determination of sodium Speed solubilize the sodium of some of the media was measured by determining the content of sodium in extracting environment using matriculating electrode model Orion 8611BN connected to the voltmeter model Orion 290A. In a typical experiment, 300 g of the medium was boiled in 900 g of deionized water in the amount of 15 minutes during this time to pre-defined intervals were selected three aliquots. The sodium content of each aliquot was determined at 25oWith using a firmly established technique for the whether the bearer of good or bad candidate for preparation of the catalyst. The results are shown in table II.

Methods of measuring pH
Measure the pH of a solution of silver was performed using a pH meter model Metrohm 744, using combined electrode model 6.0220.100 and platinum resistance thermometer model 6.1110.100 for temperature compensation. The meter was calibrated commercially available buffer solutions before each use. In the normal dimension of the sample in 50 ml of silver solution with an additive intended for use as impregnation of the catalyst was filtered in a glass chemical glass of 100 ml in 2-micron filter attached to a plastic syringe. In the solution, stir on a magnetic stirrer, lowered the pH probe and recorded after 3 min readings as the equilibrium pH. The probe was cleaned before each measurement deionized water and checked the calibration. Special attention was paid to prevent the accumulation of precipitation gl on the membrane of the electrode. This accumulation was removed by soaking the probe in a solution of ammonium hydroxide, as recommended by the manufacturer.

Example 1
The catalyst precursor obtained from the carrier And subjecting the first media washing. After washing with the ATEM introduced approximately 50 g of the solution for impregnation to immerse him in the media and kept in vacuum at to 3.33 kPa for 3 minutes Figure cesium amounted to 450 million hours/year of the final catalyst. Thereafter, the vacuum was removed and removed from the catalyst precursor excess solution impregnation by centrifugation at 500 rpm for 2 minutes Then the catalyst precursor was dried with shaking at 240oC for 4 min in a stream of air flowing with a speed of 11.3 m3/PM

Example 1A (comparative)
The carrier was impregnated as described in example 1; however, this media is not subjected to washing. Figure cesium amounted to 400 million hours/year of the final catalyst.

Example 2
The media was subjected to washing and impregnation as described in example 1. Figure cesium amounted to 450 million hours/year of the final catalyst.

Example 2A (comparative)
The carrier was impregnated as described in example 1; however, this media is not subjected to washing. Figure cesium amounted to 400 million hours/year of the final catalyst.

Example 3
The media was subjected to washing and impregnation as described in example 1. Figure cesium amounted to 300 million hours/year of the final catalyst.

Example 3A (comparative)
The media was impregnated as described in example 1; however, this media is not subjected to washing. Pokazatel the impregnation, as described in example 1. Figure cesium amounted to 450 million hours/year of the final catalyst. In addition, in the raw material solution for impregnation was added 35% aqueous hydroxide of tetraethylammonium (TAAG) to reach 117,8 Ámol HE-/ml Hell in order to reduce the activity of hydrogen ions to "measured pH" 13,2.

Example 5
In 300 ml of boiling 5 wt.% TAAG loaded 100 g of the carrier And at 15 min, then immersed six times in 300 ml of boiling deionized water every 15 minutes After that, the medium was removed and dried in a ventilated oven at 150oC for 18 hours. Then the carrier was impregnated with an indicator of cesium, comprising 400 million hours/year of the final catalyst. In addition, in the raw material solution for impregnation was added 35% aqueous hydroxide of tetraethylammonium (TAAG) to reach 117,8 Ámol OH-/ml Hell in order to reduce the activity of hydrogen ions to "measured pH" 13,6.

Example 6
The media And subjected to washing and impregnation as described in example 1. Figure cesium amounted to 720 hours per million/g of the final catalyst. In addition, TAAG dissolved in water and added in the raw material solution to a value of 117,8 Ámol OH-/ml Hell in order to reduce the activity of hydrogen ions dkol Re/g of the final catalyst.

Example 7
The media And subjected to washing and impregnation as described in example 1. Figure cesium amounted to 450 million hours/year of the final catalyst. In addition, LiOH dissolved in water and added in the raw material solution for impregnation in order to reduce the activity of hydrogen ions to "measured pH" 13,2.

Example 7 (comparative)
Media And impregnated as described in example 7; however, the carrier is not subjected to washing. Figure cesium amounted to 400 million hours/year of the final catalyst.

Example 8
300 g of the carrier And immersed in 900 ml of boiling 0.1 M solution of ammonium acetate for 15 min, then immersed in 300 ml of deionized water at 25oWith 15 minutes, then immersed three times in 300 ml of boiling deionized water each time for 15 minutes and Then the medium was removed and dried in a ventilated oven at 150oC for 18 hours. Thereafter, the carrier was impregnated as described in example 1. Figure cesium amounted to 450 million hours/year of the final catalyst. In addition, LiOH dissolved in water and added in the raw material solution for impregnation in order to reduce the activity of hydrogen ions to "measured pH" 13,2.

Example 9
The original substance-aluminium oxide for media And prom is litovali to obtain carrier And prior to the extrusion, drying and firing in a muffle furnace. The resulting carrier was identified as the carrier d Carrier D was used for preparation of the catalyst as described in example 1. Figure cesium amounted to 510 million hours/year of the final catalyst. In addition, LiOH dissolved in water and added in the raw material solution for impregnation in order to reduce the activity of hydrogen ions to "measured pH" 13,2.

Example 10
The catalyst was obtained from the carrier D as well as basically described in example 9; however, this media is not subjected to washing. Figure cesium amounted to 360 million hours/year of the final catalyst.

Example 11
100 g of the carrier And immersed in 300 ml of boiling 0.1 M solution of barium acetate at 25oWith 15 minutes, then immersed in 300 ml of deionized water at 25oWith 15 minutes, then immersed three times in 300 ml of boiling deionized water each time for 15 minutes and Then the medium was removed and dried in a ventilated oven at 150oC for 18 hours. Thereafter, the carrier was impregnated as described in example 1. Figure cesium amounted to 400 million hours/year of the final catalyst. In addition, LiOH dissolved in water and added in the raw material solution for impregnation in order to reduce the activity of hydrogen ions to "change the Ř cesium was 650 hours on million/g of the final catalyst. In addition, LiOH dissolved in water and added in the raw material solution for impregnation in order to reduce the activity of hydrogen ions to "measured pH" 13,2, and NH4ReO4dissolved in water and added in the raw material solution to provide 1.5 Ámol Re/g of the final catalyst.

The catalysts of examples 1-12 were used to produce the ethylene oxide from ethylene and oxygen. In the U-shaped stainless steel tube with an inner diameter of 6.35 mm downloaded from 3 to 5 g of the crushed catalyst. This U-shaped tube was immersed in a bath of molten metal (heat medium), and the ends attached to the flowing gas system. A lot of the used catalyst and the velocity of the incoming gas was adjusted so as to achieve time volume rate of gas 6800 ml of gas per 1 ml of catalyst per hour. Input gas pressure was 1450 kPa.

The gas mixture passed through the catalyst bed (in single mode) during the full experimental run (including running), consisted of 25% ethylene, to 7.0% oxygen, 5% carbon dioxide, 63% of nitrogen and from about 2.0 to 6.0. 'clock million on ethyl chloride.

The initial temperature of the reactor (heat medium) was 180oC. Temperature l is dostignuti constant level of ethylene oxide 1.5 about. % in the output gas stream. Data on the operation at this level of conversion was usually obtained when the catalyst was in the flow, in General, at least 1-2 days. Due to small differences in the composition of the raw gas, the velocity of the gas stream and calibration of analytical instruments used to determine the compositions of gaseous raw materials and product, a certain selectivity and activity of this catalyst may vary slightly from one experimental run to another.

Determined initial values manual for selectivity at 1.5% of ethylene oxide, they are presented in table III.

You can see that significant improvements in the properties of the catalyst are observed when the rate of solubilization of the sodium is reduced. The rate of solubilization of the sodium carriers a and b are significantly reduced (see table II) after they were subjected to the washing procedure of the media. Note that despite the low sodium content in the mass media, it has a high rate of solubilization of sodium. Further improvement is observed when the substance used for the manufacture of the medium, washed before the formation of the carrier, the carrier D.

The activity of the hydrogen ion is the reduced activity of the hydrogen ions of coating solution further improves the catalytic properties. In addition, it is obvious that the phenomenon of the pH effect is not limited to a particular composition of the catalyst, which is best illustrated in examples 6 and 11, in which the solution for impregnation add an additive that improves the selectivity, such as rhenium.


Claims

1. The carrier of the catalyst for epoxidation of olefins, with the rate of solubilization of sodium, defined by the amount of sodium released by immersing the carrier in boiling water at a ratio of boiling water to the carrier 3:1 wt./wt., not more than 5 wt.h. per million, based on the total weight of the carrier, for 5 minutes

2. A method of obtaining a catalyst carrier under item 1, in which the said speed solubilize the sodium reaching method, effective for transfer inisheer particles on the surface of the medium in the ionic state, and removing at least part of these particles, or transfer inisheer particles in the insoluble state, or translation inisheer particles in the stationary state.

3. The method according to p. 2, in which the said method selected from washing, ion exchange, evaporation, remove impurities, precipitation, complexation, and combinations thereof.

4. The catalyst for epoxidation Geomancy media characterized in that as the media use the media under item 1.

5. The catalyst p. 4, characterized in that it is suitable for the epoxidation of olefins in the gas phase.

6. The catalyst p. 5, characterized in that the said carrier is a carrier based on alumina.

7. The method of preparation of the catalyst according to any one of paragraphs.4-6, characterized in that the silver and optionally one or more promoting material is applied to the specified device under item 1 by immersing the carrier in the solution for impregnation, the activity of hydrogen ions which are reduced by adding a base, then dried in the atmosphere, reducing the silver.

8. Method for the catalytic epoxidation of alkene oxygen-containing gas, in which the use of the catalyst according to any one of paragraphs.4-6 or the catalyst obtained under item 7.

9. The method according to p. 8, wherein the oxygen-containing gas type, at least one of the oxides of nitrogen.

 

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