The catalyst for vapor-phase epoxidation of olefins and method for producing the carrier for him

 

(57) Abstract:

The invention relates to a catalyst for receipt of ethylene oxide, which contains silver and one or more promoters of the alkali metal supported on a carrier having a crushing strength of at least 2.3 kg and a specific bulk density of at least about 0.48 kg/l, which includes the first and second components of aluminum oxide, the first component is aluminum oxide in the form of particles having an average crystallite size of 0.4 - 4 μm, is from 95% to 40% of the total weight of alumina in the carrier, and the second component is aluminum oxide, obtained in situ silylium process, is the remainder of the alumina in the carrier. The optional media type titanium oxide. Also described is a method of obtaining media for the above-mentioned catalyst. Catalysts having a unique carrier of aluminum oxide, have improved selectivity and/or activity compared to catalysts containing the usual native aluminum oxide. 2 C. and 15 C.p. f-crystals, 6 PL.

The invention relates to containing silver catalysts, suitable for display olefins do not contain allamuchy by using a unique media-based - aluminum oxide.

The catalysts for production of ethylene oxide from ethylene and molecular oxygen in most cases represent a silver catalyst on the carrier. Such catalysts usually promotirovat alkaline metals. The use of minor amounts of alkali metals potassium, rubidium and cesium as suitable promoters in silver catalysts on the media mentioned in U.S. patent N 3962136, published June 8, 1976, U.S. patent N 4010115, published on 1 March 1977. The use of other co-promoters, such as rhenium, or in conjunction with sulfur, molybdenum, tungsten and chromium are described in U.S. patent N 4766105, publ. August 23, 1988, and U.S. patent N 4808738, publ. February 28, 1989 In U.S. patent N 4908343, publ. March 13, 1990 , presents a silver catalyst on a carrier containing a mixture of cesium salts and one or more salts of alkali and alkaline earth metal.

In U.S. patent N 4897498, publ. January 30, 1990, describes the use of catalysts based on silver, promoted by alkali metal supported on a carrier, when epoxydecane olefins having no allylic hydrogen.

The use of carriers of catalysts based on alumina was previously OPRA 1991, U.S. patent N 5037794, publ. August 6, 1991, and U.S. patent N 4874739, publ. on 17 October 1989, These native aluminum oxide is widely used in the field of catalysis, and they are particularly suitable when the primary aluminium oxide is the oxide of aluminum, and preferably abrasion resistance.

In U.S. patent N 5063195, publ. in November 1991, describes catalysts for production of ethylene oxide on a carrier which is prepared from a three-hydrate of alumina, boehmite (which is also hydrated oxide of aluminum, fluoride and fillers.

This invention relates to a catalyst suitable for the epoxidation of ethylene with oxygen in the vapor phase, which contains a catalytically effective amount of silver and a promoting amount of alkali metal supported on a carrier on the basis of aluminum oxide, having a crushing strength of at least 2.3 kg and a specific bulk density of at least 0.48 kg/l, which includes the first and second components of aluminum oxide, the first component is aluminum oxide in the form of particles having an average crystallite size from 0.4 to 4 μm, provides from 95% to 40% the total weight of aluminum oxide wear in the in - alumina in the carrier.

It has been found that catalysts having such a unique medium aluminum oxide, have improved selectivity and/or activity compared to catalysts containing the usual native aluminum oxide. These catalysts also have improved stability, selectivity and/or stability of the activity.

Next will be described a carrier, the catalyst containing the medium, and a catalyst.

The carrier of the catalyst in the present invention is a new catalyst carrier on the basis of aluminum oxide having crushing strength (which is measured on the dynamometer Compton, model 50-PR) of at least 2.3 kg and a specific bulk density (which is measured by ASTM D-4699-87 (American standard test method), modified by using a cylinder with an inner diameter 9,52 cm and a length of 45.7 cm) of at least 0.48 kg/l, preferably at least 0,56 kg/l and more preferably at least 0.6 kg/l, which contains the first and second components of aluminum oxide, the first component is aluminum oxide in the form of particles having an average crystallite size from 0.4 on the component aluminium oxide obtained in situ silylium process that complements the remainder of the alumina in the carrier.

Used here, the term "solely process" refers to a process which includes heating the Sol and/or gel aluminum oxide (i.e., hydrated aluminum oxide) to a temperature at which the transformation of at least part of the Sol and/or gel of aluminum oxide in the aluminum oxide having a corundum crystal structure (i.e., a hexagonal structure with dense packing).

The transformation is usually carried out at a temperature of at least 400oC, preferably above 1100oC and more preferably from 1100 to 1500oC.

The catalyst carrier obtained by the method, which includes:

a) preparation of a mixture containing:

(I) at least Dean component - aluminium oxide with an average particle size of 3 to 8 μm and an average crystallite size from 0.4 to 4 microns;

(II) the hydrated precursor is aluminum oxide (Sol and/or gel) in an amount sufficient to provide from 5% by weight to 60% by weight of the total weight of alumina in the catalyst carrier,

(III) burnable material in an amount of from 5% to 40% relative who (b) extruding the mixture into a molded product of the required form and

(c) firing to convert the precursor of aluminium oxide - aluminium oxide with obtaining a carrier for catalyst, in which particles of aluminum oxide with an average particle size from 3 to 8 μm and an average crystallite size from 0.4 to 4 μm dispersed in the matrix of aluminum oxide obtained from material predecessor.

The catalyst carrier may consist of several components - aluminum oxide, selected to provide the required physical properties, including porosity, pore volume, crushing strength, etc. Often preferred is a combination of two different oxides of aluminum, while the first component with a large particle size is mixed with the second component with particles of small size at a weight ratio of from 10:90 to 90:10. First typically comprises from 10% to 90%, preferably from 40% to 20% by weight of the first source of alumina, and the second component typically comprises from 10 to 90%, preferably 20% to 60% by weight of a source of aluminum oxide. The purpose of the above is to obtain the specific surface of the final annealed media from 0.4 to 5 m2/year Used herein, the term "specific surface area" means the specific surface, measured in m is supplemented flax surface in finite media partly less than free particles of aluminum oxide. Thus, a suitable mixture may include, for example, two types of part - alumina, while the first has a specific surface area of from 0.9 to 1.4 and preferably 1 m2/g, average particle size from 2 to 4 and preferably from 3 to 3.4 μm and an average crystallite size of 1.6 to 2.2 μm, and the second has a specific surface area of from 3 to 5 m2/g, average particle size from 4 to 8 μm and an average crystallite size 0.4 to 0.7 microns.

The hydrated precursor of aluminum oxide, preferably based on the monohydrate such as boehmite, but good results were obtained also if the precursor contains a mixture of boehmite with aluminium trihydrate such as gibbsite or bayerite. When using this mixture, it is preferable to use a weight ratio monohydrate (boehmite) to trihydrate from 1: 10 to 1:3 and more preferably from 1:8 to 1:4. When the precursor of aluminium oxide contains alumina trihydrate, it usually contains from 10% to 35% by weight of the three-hydrate of aluminum oxide to the total weight of alumina in the carrier. Although there may be used other trihydrate of aluminum oxide, the most commonly used alumina trihydrate is gibbsite, with the nick - aluminum oxide using a seed crystal, which can be any material effective to obtain nucleation centers in the predecessor to lower the transition temperature at which the aluminum oxide is transformed into a - alumina. Seed, with which you can achieve this goal, usually have the same type of crystal lattice, which itself is aluminum oxide, the dimensions of the lattice is not too much different from the dimensions of the grid - alumina. It is clear that the most appropriate seed is self - aluminum oxide and the preferred seed are particles of alpha-alumina with a size less than 1 micron. In a preferred embodiment, the seed-alumina has an average particle size of less than 0.2 micrometer and ranges from 0.2% to 5% by weight relative to the total weight of aluminum oxide, defined in the form of aluminum oxide in the catalyst carrier. However, you can use other seed, for example, oxide of iron (II), chromium oxide and certain complex oxides of titanium.

The aluminum oxide formed from a precursor containing a seed crystal, when extruded mixture usually burn, has a much smaller crystals than cha is their high temperature for a long period of time. After containing the seed soleley material has a crystalline structure with crystallite size less than microns, but it is maintained at temperatures above 1400oC for a long period of time, when this starts crystal growth, and differentiation may become less obvious.

The final calcined carrier preferably has a porosity of at least 50% or more, preferably from 60 to 75%, the crushing strength of at least 2.3 kg and a specific bulk density of at least 0.5 mg/l, preferably at least 0.6 kg/l Specific surface of the final annealed product is preferably from 0.4 to 5 m2/g and more preferably from 0.6 to 1.2 m2/,

It was found that it is often advantageous to add to the extrudable mixture of a titanium oxide in an amount of from 0.05 to 1%, preferably from 0.05 to 0.5%, more preferably 0.08 to 0.4% and most preferably from 0.08 to 0.25 by weight of burned media.

Certain forms of aluminum oxide and a binder can also contain titanium oxide in the form of impurities or components. In this case, the titanium oxide is not considered in the quantities listed above. The titanium oxide may be dokazannyj types should be understood under the term "titanium oxide". I believe that the titanium oxide can act as an inhibitor of growth of crystals in the aluminum oxide formed in the conversion of the precursor containing the seed. Therefore, it can be expected that other such materials, such as zirconium oxide or magnesium, which can act in this capacity, can be useful as substitutes for titanium oxide. I believe that there are complex multi-stage reaction in the solid phase between the aluminum oxide/binder alloy and titanium oxide added to the medium, which leads to an increase in the strength and density of the media.

The titanium oxide is preferably in the form of powder with a relatively high specific surface, i.e. at least 8 and preferably from 8 to 300 m2/,

In practice, the preferred titanium oxides are amorphous structure or a structure of anatase. Without reference to any theory, it is possible to assume that rutelinae structure of titanium oxide is usually no advantage that can be obtained from the amorphous and anatase structures of titanium oxide, because he usually has a much smaller specific surface area. Industrial pigment grade titanium oxide can also Yes is the missing material and/or binder and water, molded in various shapes and fired.

Burnable material is such a material, which is added to the mixture during firing in order to completely delete it from the carrier, leaving the adjustable porosity in the media. These materials are carbonaceous materials such as coal, coal powder, graphite, powdered plastics, such as polyethylene, polystyrene and polycarbonate, rosin, cellulose, and materials based on cellulose, sawdust and other materials of vegetable origin, such as the shell of groundnuts, for example, American walnut, cashew, walnut and hazelnut.

Burnable materials based on carbon can also serve as a binder. Burnable materials used in such quantity and at such a size distribution that provide the ultimate in media pore volume of water in the range from 0.2 to 0.6 mg/L. Burnable materials are usually taken in an amount of 5 to 40% by weight of the weight of alumina in the carrier. Preferred burnable materials are materials derived from cellulose, such as the shell of groundnuts.

The term "binder", as used here, refers to Vasu shape by extrusion or granulation These binders provide drying and firing the molded material without destruction. Such binders are usually "sticky" organic materials such as polyvinyl alcohols or cellulose materials. Binders can also serve as an aid for the extrusion. In certain cases, instead of binders can be used patiserie acid.

Although it can be assumed that the aluminum oxide formed from containing a seed crystal precursor, acts in some sense as a matrix binder that holds together the remaining particles of aluminum oxide, it is generally preferable to add to the mixture to impart additional strength to the burnt media ceramic binder.

Ceramic binder is typically present in an amount of from 1 to 3% by weight of the total weight of components aluminium oxide, expressed in the form of aluminum oxide. Conventional ceramic binder materials can be used after firing, they usually include components (oxides), such as silicon dioxide, aluminum oxide, alkali metal oxides, alkali earth metal oxides, iron oxide and titanium oxide, with the first two components are predominant.

After media components are mixed by grinding, the mixed material ekstragiruyut in a molded granules, such as cylinders, rings, three-and four-petalled particles and T. D. To facilitate the extrusion process can be used "subsidiary means for the extrusion, for example Vaseline Petroleum Jelly (vaseline) and other organic lubricants. To remove water, which can be transformed into steam during firing and destroy extrudate form, the extruded material is dried. After drying to a low water content, i.e. less than 2%, the extruded material is calcined under conditions sufficient to remove burnable materials, auxiliary products for extrusion and binders and to melt parts of aluminum oxide in porous, solid mass. Firing is usually carried out in an oxidizing atmosphere, such as oxygen gas or preferably air, at a maximum temperature of more than 1300oC, preferably in the range of from 1350oC to 1500o

Burned media and catalysts derived from them, usually have a pore volume of water in the range from 0.2 to 0.6, preferably from 0.3 to 0.5 ml/g and specific surface area in the range from 0.15 to 3, preferably from 0.3 to 2 m2/,

The support preferably has a low content of sodium, which is less than 0.06% by weight. In practice it is very difficult to obtain a composition that does not contain sodium; it was found that usually is acceptable the soda content of from 0.02 to 0.06% by weight.

The media described above are particularly suitable for the preparation of catalysts suitable for receipt of ethylene oxide, which have a high initial selectivity.

The catalyst of the present invention includes a catalytically effective amount of silver and a promoting amount of alkali metal(s) deposited on the carrier, which is described above. Optional could be other promoters in promoting quantities, such as rare earth, magnesium, rhenium and rhenium promoters selected from sulfur, chromium, molybdenum, tungsten and mixtures thereof.

In General, the catalyst of the present invention is obtained by impregnating a porous refractory carrier, VK dissolved in an appropriate solvent in the amount sufficient to be applied on the carrier silver 1 to 40, preferably from 1 to 30% by weight of the total weight of the catalyst. Then the impregnated carrier is separated from the solution and deposited compound of silver is reduced to metallic silver.

Suitable ions or compound (I), and/or salt and an alkali metal dissolved in an appropriate solvent, may be supported on a carrier before applying the silver, or simultaneously, or after application of the silver. Suitable optional used promotor compound(I), complex(s) compound(I) and/or salt(s) dissolved(s) in an appropriate solvent, may be supported on a carrier along with silver and/or alkali metal.

The catalysts of the present invention receive through the methods by which the promoter of the alkali metal, as well as any additional promoters in the form of soluble salts and/or compounds are applied to the catalyst and/or the media before applying, simultaneously with the application or after the application of silver and every other of the above substances. The preferred method is the simultaneous deposition of silver and alkali metal on a carrier, i.e. one stud is as and/or after application of the silver will also lead to obtaining appropriate catalysts.

The promoting amount of alkali metal or mixtures of alkali metal applied to porous media by using the appropriate solution. Although alkali metals exist in a pure metallic state, they are not suitable for use in this form. They are used in the form of ions or compounds of alkali metal dissolved in a suitable solvent with the purpose of impregnation. The carrier is impregnated with a solution containing ions of the promoter of the alkali metal salt(s) and/or compound(s), before impregnation, during impregnation or after impregnation with silver ions or salt(s), integrated(I) compound(s), and/or connection(s). The promoter of the alkali metal may be deposited on the carrier even after restoring to metallic silver. The promoting amount of alkali metal will depend on several factors, such as specific surface area, structure, pore and surface chemical properties of the medium, the content of silver in the catalyst and characteristics of ions used in combination with a cation of an alkali metal, an optional co-promoter.

The number of promoter of alkali metal deposited on novtel is preferably from 20 to 1500 parts per million by weight of the total weight of the catalyst. Most preferably the amount of the promoter is in the range from 50 to 1000 parts per million by weight of the total weight of the catalyst.

With the purpose of convenience, the amount of alkali metal deposited on a carrier or present in the catalyst, expressed in terms of metal. Without limiting the scope of the invention is believed that the compounds of alkali metal oxide are compounds. In particular, suppose that the compounds of the alkali metal are likely to be in the form of mixed surface oxides or double surface oxides or complex surface oxides with aluminium carrier and/or silver catalyst, possibly in combination with varieties contained in the reaction mixture or formed from the reaction mixture, such as chlorides or carbonates or residual variations of the treatment(s) solution(s).

In a preferred embodiment, at least a major part (more than 50% weight. %) alkali metals are selected from the group consisting of potassium, rubidium, cesium and mixtures thereof.

The preferred promoter, which is the alkali metal is cesium. Particularly preferred promoter of the alkali metal preterit preferably from sodium, lithium and mixtures thereof, with lithium is preferred.

It should be understood that the number of promoters of alkali metal catalysts are not inevitably the total quantities of these metals present in the catalyst. Most likely they are the quantities of the promoters of the alkali metal, which is added to the catalyst by impregnation of the respective solution, ions, salts and/or compounds and/or complex compounds of alkali metals. These amounts do not include amounts of alkali metals, which are fixed on the carrier, for example, by burning, or which are not extracted in appropriate solvent, such as water or a lower alcohol or amine, or mixtures thereof, and do not provide the promoting action. I also think that the ion source promoter of alkaline metal salts and/or compounds used for promotion of the catalyst, may be the media. The media may contain extractable amount of alkali metal that can be extracted with appropriate solvent, such as water or a lower alcohol, thus obtaining the impregnating solution from which the precipitate or presidida on the carrier ions are alkali metal is d speed up the start process for catalysts. When the catalyst is added chloride, the carrier may be impregnated with a solution containing ions of chloride compounds, salt(s), and/or connections, and before impregnation, during impregnation or after impregnation with silver ions or salt(s), a complex compound(s) and/or compound(s), before impregnation, during impregnation or after impregnation ions promoter or salt(s), integrated(I) compound(s), and/or connection(s). Chloride compound may be supported on a carrier even after restoring to metallic silver. Suitable chloride-containing salt used to produce an impregnating solution include chlorides promoter, for example, lithium chloride, sodium chloride, potassium chloride, rubidium chloride and cesium chloride, and ammonium chloride. Ammonium chloride is the preferred salt for use in obtaining chloride-containing impregnating solution. Suitable are also other compounds which decompose during processing of the catalyst to the chloride ion. Chloride-containing impregnating solutions usually contain at least small amounts of water to increase the solubility of chloride-containing salts or compounds. In combination with silver and promoters of shery other promoters include rhenium, sulfate, molybdate, tungstate and chromate (see U.S. patent N 4766105); sulfate anion, fluoride anion, the oxy-anions of group 3b-6b (see patent N 5102848); (i) the oxy-anions of an element selected from groups 3-7 (ii) and alkali metal salt with halide anions, and oxy-anions selected from groups 3A-7a and 3b-7b (see U.S. patent N 4908343).

Thus obtained impregnated carrier is heated to restore silver to metallic silver. It is usually heated to a temperature in the range of 50oC to 600oC for a period of time sufficient for recovery of silver salts, compounds or complex to metallic silver and to the formation of a layer of thin-dispersed silver, which is associated with the surface of the carrier from the outside geometric and surface pores.

During the heating stage on the media can be skipped air or other oxidizing gas, the reducing gas, inert gas or mixtures thereof.

One way to get containing silver catalyst described in patent CIF N 3702259. Other methods of obtaining containing silver catalysts which also contain higher amounts of the promoters of the alkali metal as described in U.S. patent N 4010115, aderrasi higher amount of alkali metal and rhenium promoters, disclosed in U.S. patent N 4761394, and methods of obtaining containing silver catalysts containing higher amounts of alkali metal, rhenium promoters and copromotion rhenium disclosed in U.S. patent N 4766105. Methods of obtaining silver-containing catalysts with different promoters is presented in U.S. patent N 4908343 and 5057481.

The concentration of silver (in terms of metal) containing silver solution will be from 1 g/l to the solubility limit in the case when using a single impregnation. When using a single phase impregnation, the concentration of alkali metal (in terms of the metal) ranges from 110-3g/l to 12 g/l and preferably from 1010-3g/l to 12 g/L.

The concentration selected within the above ranges depend on the pore volume of the catalyst, the desired content in the final catalyst and whether the impregnated one or more times.

Regardless of the form in which there is the silver in solution prior to deposition on a carrier, usually use the term "recovery of metallic silver", although, meanwhile, often the decomposition by heating. In this text, prefer to use the term "in the Oia can usually change depending on circumstances from 0.5 minutes to about 8 hours.

On an industrial scale ethylene and oxygen are turned into ethylenoxide the reactor, which contains a large stationary tubular heat exchanger, containing several thousand tubes filled with catalysts. In the annular zone of the reactor to remove the heat of reaction using the cooler. Coolant temperature is often used as an indicator of catalytic activity, high coolant temperature correspond to the reduced catalytic activity.

In the reaction of ethylene with oxygen to obtain ethylene oxide ethylene is usually present in at least double the excess (in moles) in relation to oxygen, but usually the amount of ethylene is much higher. Therefore, the degree of transformation is usually calculated according to the molar concentration of oxygen that is consumed and the reaction of formation of ethylene oxide and oxidized by-products.

The degree of conversion of oxygen depends on the reaction temperature and the reaction temperature is a measure of the activity of the used catalyst. The value of T40specifies the temperature at 40% conversion of oxygen in the reactor, and the value T is expressed inoC. This temperature for any given rolled the used catalyst and the reaction conditions. Selectivity (ethylene oxide) indicates the molar amount of ethylene oxide in the reaction product compared to the total molar quantity of the transformed ethylene.

This selectivity is specified in the form of S40that means selectivity at 40% degree of conversion of oxygen.

Conditions for such oxidation reactions in the presence of a silver catalyst in accordance with the present invention largely includes conditions that have already been described in the literature prior art. This applies, for example, to the appropriate temperatures, pressures, reaction time diluents, such as nitrogen, carbon dioxide, water vapor, argon, methane or other saturated hydrocarbons, in the presence of moderators to control the catalytic action, for example, 1-2-dichloroethane, vinyl chloride, ethylchloride or chlorinated Polyphenylene connections to the desirability of using recycling or successive transformations in different reactors to increase yield of ethylene oxide and any other special conditions that can be selected in the method of producing ethylene oxide. Usually use pressure is used as a reagent, can be obtained from conventional sources. Suitable oxygen-containing raw materials can, essentially, or consist of relatively pure oxygen, concentrated oxygen stream comprising oxygen in the overwhelming number, with smaller amounts of one or more diluents, such as nitrogen or argon, or another oxygen-containing stream such as air. Therefore, the use of silver catalysts in ethylenoxide reactions in no way restricted to the specific conditions of those that are known to be effective.

The tables only for the purpose of illustration, show the range of conditions that are often used in conventional industrial ethylenoxide reactors and which are also suitable for this method.

In the preferred application containing silver catalyst in accordance with the invention, the ethylene oxide when oxygen-containing gas in contact with ethylene in the presence of these catalysts at a temperature in the range from 180oC to 330oC and preferably from 200oC to 325oC.

Although the catalysts of the present invention use predefined, not having allylic hydrogen, such as those widely available in the US patent N 4897498. Examples of such olefins can serve as butadiene, tertiary butylation, viniferin, methyl vinyl ketone are, N-vinylpyrrolidone, etc. currently preferred olefin for use in this method is butadiene, because of its availability, relatively low cost and wide range of possible applications. In U.S. patent N 5081096, publ. on January 14, 1992, describes promoted by alkali metal-based catalyst of silver on a medium which is used for the epoxidation of butadiene, by treating the catalyst precursor, after impregnation of silver-containing compound, a hydrogen-containing gas at a temperature of not higher than 350oC. The same can be carried out with the catalysts in accordance with the present invention.

The invention is illustrated by the examples of carrying out the invention.

Getting media.

The carrier of A:

Ceramic components were mixed for one minute with burnable material (powder from the shell of a walnut) and boric acid.

Then added water and the seed component, with water up to approximately 30% by weight relative to the total amount of solids present. The mixture was stirred for a time of from 2 to 4 minutes and then as an aid for the extrusion was added 5% by weight of petroleum butter (vaseline) (Vaseline is the brand name) relative to the weight of the ceramic components. Then the mixture was stirred for from 2 to 4 minutes, after which he extrudible in the form of a hollow cylinder and dried to a free water content less than 2%. The mixture is then burned in a tunnel furnace at a maximum temperature of about 1500oC for about 4 hours. The composition of the medium are presented in table. 2, and its physical properties in table. 3.

The carrier of B:

Carrier B was obtained in a manner similar to that received carrier A, except that the composition of the medium was added to the titanium oxide. The composition of the medium are presented in table. 2, and its physical properties in table. 3.

Media C:

Carrier C was obtained in a manner similar to that received carrier A, except that the medium did not contain component-alumina obtained silylium process, and to the composition of the medium is not added seed component, i.e.- alumina N 5. The composition of the medium are presented in table. 2, and its physical properties in table. 3.

Media D:

Neitzel component aluminum oxide obtained silylium process, and to the composition of the medium is not added seed component, i.e. - alumina N 5. The composition of the media is presented in table II, and its physical properties in table III.

Obtaining a catalyst.

The following explanatory embodiment of the invention describes the preparation procedures for the production of catalysts of the present invention (catalysts A, B, C, D, and F) and comparative catalyst (Comparative catalyst E and G), and the method of measuring the properties of these catalysts.

Part a: Obtaining an initial solution of silver oxalate/Ethylenediamine for use in obtaining catalyst:

1) Dissolved 415 g of sodium hydroxide chemical purity in 2340 ml of deionized water. Set temperature 50oC.

2) was Dissolved 1699 (high-purity) of silver nitrate in 2100 ml of deionized water. Set temperature 50oC.

3) To a solution of silver nitrite with stirring and maintaining the temperature of 50oC was slowly added a solution of sodium hydroxide. After completion of the addition was carried out by stirring for 15 minutes and then the temperature was lowered to 410oC.

oC. This process was repeated up until the conductivity of the remote water was less than 90 μm ho/see Then added to 1500 ml of deionized water.

5) Added 630 g of dihydrate of high-purity oxalic acid portions of approximately 100 g Maintained the temperature at 40oC and the mixture was thoroughly mixed. Slowly added the last portion of the dihydrate of oxalic acid and adjusted to pH so that it would not fall below a value of 7.8.

6) Of the mixture was removed the maximum amount of water when you clean the filter folders in order to form a highly concentrated silver-containing suspension. A slurry of silver oxalate was cooled to 30oC.

7) Added 699 g of 92 wt.% Ethylenediamine (8% deionized water). Provided that the temperature during the addition does not exceed the 30oC.

The above procedure resulted in the receipt of a solution containing catalysts A, B, C, D and F and the comparative catalysts E and g

Part B: to Obtain solutions for impregnation.

For catalyst AA:

161.3 g containing silver initial solution with a relative density 1.543 dissolved 4.2 g of water and 13.5 g of monoethanolamine. 0.0350 g NH4F was dissolved in 2 ml of water and added to the silver solution. To 60 g of the above diluted solution of silver added CsOH (50% solution in water) in an amount of 0.1367 g, and the resulting mixture is used for impregnation of the carrier.

For catalyst B:

175.4 g containing silver solution with a relative density of 1.53 diluted 3.6 g of water. 0.0387 g NH4F was dissolved in 2 cm3water and added to the silver solution. To 60 g of the above diluted solution of silver added CsOH (50% solution in water) in an amount of 0.1536 g, and the resulting mixture is used for impregnation of the carrier.

For catalyst C:

165.3 g containing silver initial solution with a relative density of 1.55 diluted 13.9 g of monoethanolamine. 0.0426 g NH4F was dissolved in 2.5 g of water and added to the silver solution. 60 the above diluted solution of silver added CsOH (50% solution in water) in an amount 0.1406 g, and the resulting mixture is used for impregnation but what testu 1.555 diluted 17.8 g of water. 0.0868 g (NH4)ReO4dissolved in 2 cm3a mixture of water/DA (50/50 by weight) and added to the silver solution. To 60 g of the above diluted solution of silver added CsOH (50% solution in water) in an amount of 0.1743 g, and the resulting mixture is used for impregnation of the carrier.

For the comparative catalyst E:

129.7 g containing silver initial solution containing 29.7% Ag, dissolved 14 g of water and 6.3 g of monoethanolamine. 0.0285 g NH4F was dissolved in 2 ml of water and added to the silver solution. To 50 g of the above diluted solution of silver added CsOH (50% solution in water) 0.0582 g, and the resulting mixture is used for impregnation of the carrier.

For catalyst F:

168 g containing silver initial solution with a relative density 1.546 diluted 10.9 g of water 0.1442 g (NH4)ReO4, 0,0704 g Li2SO4H2O, 0.303 g LiNO3dissolved in a mixture of approximately 2 ml of Ethylenediamine/water (50/50 by weight) and added to the silver solution. To 50 g of the above diluted silver added CsOH (50% solution in water) in an amount of 0.1985 g, and the resulting mixture is used for impregnation of the carrier.

For the comparative catalyst G:

101 g containing silver original races>O 0.1616 g LiNO3dissolved in approximately 2.0 g of ethylene diamine/water (50/50 by weight) and added to the silver solution. To 50 g of the above diluted solution of silver added CsOH (50% solution in water) in an amount of 0.111 g, and the resulting mixture is used for impregnation of the carrier.

Part C. the Impregnation of the catalyst and curing.

Catalyst A:

Approximately 30 g of carrier A, as described in table. 2 and 3), kept under a vacuum of 25 mm for 3 minutes at room temperature. Then for impregnation of the carrier introduced approximately 50 to 60 g of the impregnating solution (described above in part B, entitled "catalyst A"), and within 3 minutes had maintained a vacuum of 25 mm At the end of this period, the vacuum was disconnected from the media by centrifugation for 2 minutes at 500 revolutions per minute removed the excess impregnating solution. If the impregnating solution was obtained without monoethanolamine, then the impregnated carrier was then utverjdali by continuous shaking at 850 l/h air stream flowing through the cross-section of approximately 19.4 - 32.3 cm3when 240-270oC for 3-6 minutes. If the impregnating solution has a significant amount of monoethanolamine, the re from 250 to 270oC for 4-8 minutes. After that cured the catalyst was ready for testing. Properties of catalyst A are shown in table. 4.

Catalyst B:

Catalyst B was obtained in the same manner as catalyst A, except that instead of the catalyst carrier A used catalyst carrier B and applied by impregnating solution was the solution described in part B, entitled "catalyst B". Properties of catalyst B are shown in table. 4.

Catalyst C:

Catalyst C was obtained with the use of dual methods of impregnation. In this method, 120 g of catalyst carrier B has infiltrated 240 g containing silver initial solution with a relative density 1.555. The impregnated carrier was dried and progulivali for the decomposition of silver salts to metallic silver. Water pore volume was determined after the first impregnation and used to calculate the concentrations of the absorbed substance.

The second impregnation was carried out by impregnating solution described in part B, entitled "catalyst C". The catalyst was utverjdali in a manner similar to that described above. Properties of catalyst C are shown in table. 4.

Catalyst D:

Approximately 30 g novtel the impregnation of the carrier introduced approximately 50 to 60 g of the impregnating solution (described in part B, entitled "catalyst D") and for a further 3 minutes maintained a vacuum of 25 mm At the end of this period, the vacuum was removed, and from the media by centrifugation for 2 minutes at 500 revolutions per minute removed the excess impregnating solution. If the impregnating solution was obtained without monoethanolamine, then the impregnated carrier was then utverjdali with continuous shaking in the air stream flowing through the cross-section of approximately 19.4-32.3 cm2with the speed of 850 l/h at 240-270oC for 3-6 minutes. If the impregnating solution has a significant amount of monoethanolamine, then the impregnated carrier was utverjdali with continuous shaking in the air stream with a velocity of 850 l/h at a temperature of from 250oC to 270oC for 4-8 minutes. After that cured the catalyst was ready for testing. Properties of catalyst D are shown in table. 4.

Comparative catalyst E:

Comparative catalyst E was obtained in the same manner as catalyst A, except that instead of the catalyst carrier A used catalyst carrier C and used an impregnating solution was the solution described in part B, entitled "For the comparative catalyst E".

Properties of comparative catalyst E shown in the table. 4.eat that instead of the catalyst carrier A used catalyst carrier B, and used an impregnating solution was the solution, which is described above in part B, entitled "catalyst F". Properties of catalyst F are shown below in table IV.

Comparative catalyst G:

Comparative catalyst G was obtained in the same manner as catalyst D, except that instead of the catalyst carrier A used catalyst carrier D, and used an impregnating solution was the solution, which is described above in part B, entitled "catalyst G". Properties of catalyst G is shown below in table. 4.

The actual silver content of the catalyst can be determined by any of several standard published methods. The actual level of cesium in the catalyst can be determined by using the initial solution of cesium hydroxide, which were labeled with radioactive isotope of cesium, upon receipt of the catalyst. The content of cesium in the catalyst can then be determined by measuring the radioactivity of the catalyst. In addition, the content of cesium in the catalyst can be determined by leaching of the catalyst boiling neionizirovannykh 10 g of catalyst in boiling 20 ml of water for 5 minutes, repeat the above for more than 2 times, mixing extracts and determine the present amount of the alkali metal by comparison with standard solutions of comparative alkali metals using atomic absorption spectroscopy (when using a Varian Techtron Model 1200 or equivalent).

Part D: the test Conditions of the catalyst in the standard microreactor method.

A. For catalysts A, B, C and comparative catalyst E.

From 1 to 3 g of crushed catalyst with a particle size 0.841 - 0.595 mm (20 - 30 mesh) was loaded into a U-shaped stainless steel tube with a diameter of 6.4 mm U-shaped tube was immersed in a bath with the metal melt (heating medium) and the ends connected to the gas flow. To achieve an average hourly rate of gas supply 6800 adjusted the weight of the used catalyst and the flow rate of inlet gas. The gas pressure at the outlet was 1550 kPa.

The gas mixture passed through the catalyst bed (once) during all tests (including the home), consisted of 25% ethylene, 7% oxygen, 5% carbon dioxide, from 1.25 to 5 frequent per million by weight of ethylchloride, while the rest was nitrogen/argon.

The beginning of the 190oC, 1 hour to 200oC for 1 h to 210oC, 2 hours to 220oC, 2 hours before 225oC, 2 hours to 230oC, and then the temperature was regulated so as to provide 1.5% of ethylene oxide at the outlet of the reactor. Under these conditions, measured the selectivity of the catalyst (S1.5) and the catalyst (T1,5).

To compare the properties of the catalysts tested at different times, the catalysts A, B, C and comparative catalyst E was tested simultaneously with the standard catalyst of comparison, which has S1,5=81.7% and T1,5=235oC.

Catalysts A, B, C and comparative catalyst E obtained above were tested using the above methods, the results are shown in table. 5.

B. For catalyst D:

Catalyst D was tested in a manner similar to that described above for the catalysts A, B, C and comparative catalyst E, except that the process was as follows.

The initial temperature of the reactor (heat medium) was 225oC. After 3 hours of being under a stream of nitrogen at this initial temperature, the temperature was increased to 235oC for 1 hour, then to 245oC echeneidae. The results are shown in table. 5.

As you can see from the table, the initial selectivity of the catalysts A, B, C and D in comparison with the initial selectivity of the comparative catalyst E has improved. You can also see that the initial activity of the catalysts A, B and C also improved compared with the initial activity of catalyst E.

C. For catalyst F and comparative catalyst G:

From 3 to 5 g of the crushed catalyst (14-20 mesh) was loaded into a U-shaped tube made of stainless steel with a diameter of 1/4 inch (6.350 mm). U-obrazow tube immersed in a bath with the metal melt (heating medium), and the ends connected to the gas flow. To achieve an average hourly rate of gas supply 3300 adjusted the weight of the used catalyst and the flow rate of inlet gas. The gas pressure at the output amounted to 210 psig (7.031 2.10 = 14.765 kg/cm2).

The gas mixture passed through the catalyst bed (once) during the test (including initial) consisted of 30% ethylene, 8.5% of oxygen, 5% carbon dioxide, from 1.5 to 5 frequent. per million by volume of ethylchloride, while the rest was nitrogen/argon.

Before contact with reactive gases catalysts on the x catalysts or for a longer period of time for starevich, but not exposed to the test catalysts (control).

The initial temperature of the reactor (heat medium) was 225oC. After 1 hour of incubation at this initial temperature, the temperature was increased to 235oC, then for one hour to 245oC. the temperature was Then adjusted so that, to achieve the degree of conversion of oxygen equal to 40% (T40).

To determine the optimal amount of retarder number of moderator changed within 4-24 hours, and when the catalyst was in the flow of time is about 24 hours, usually received T40and S40listed in the table. 5.

Due to the small difference in composition of the source gas, the gas flow rates and the calibration of analytical instruments used to determine the compositions of the original and the received gas, measured selectivity and activity of this catalyst can vary slightly from one test to another.

For the possibility of a significant comparison of the properties of the catalysts tested at different times, all of the catalysts described in this illustrative implementation of the method was tested simultaneously is Aligator F and the comparative catalyst G, obtained above, were tested using the above methods, the results are shown in table. 6.

As you can see from the table. 6, the initial activity and the initial selectivity of the catalyst F was improved compared to the initial activity and the initial selectivity of the comparative catalyst G.

1. The catalyst for vapor-phase epoxidation of olefins having no allylic hydrogen, in particular ethylene, oxygen, containing a catalytically effective amount of silver and a promoting amount of alkali metal deposited on a carrier-Al2O3having a crushing strength of at least 2.3 kg and a specific bulk density of at least 0.48 kg/l, characterized in that it contains media that includes first and second components of aluminum oxide, the first component is aluminum oxide in the form of particles having an average crystal size of 0.4 - 4 μm, is from 95% to 40% of the total weight of alumina in the carrier, and the second component is aluminum oxide, obtained in situ silylium process of the hydrated precursor of alpha alumina possible with the introduction of the seed is the remainder of the aluminum oxide in nouche the first component and the second component, the first component is contained in an amount of from 10% to 90% by weight of the first component in the form of particles with an average particle size of 2.5 - 4 μm and an average crystallite size of 1.5 - 2.5 μm and the second component is contained in an amount of from 90% to 10% by weight of the first component in the form of particles with an average particle size of 4 to 10 μm and an average crystallite size of 0.4 - 0.8 μm.

3. The catalyst p. 1, characterized in that the second component is alumina carrier obtained silylium way with the introduction of the seed.

4. The catalyst p. 3, characterized in that the second component is aluminum oxide obtained silylium method using an effective amount of a seed crystal of aluminum oxide with a particle size less than 1 micron.

5. The catalyst p. 1, characterized in that the medium additionally contains titanium oxide in an amount of 0.05 - 1% by weight relative to the weight of alumina in the carrier.

6. The catalyst p. 1, characterized in that the carrier has a pore volume of 0.3 to 0.6 ml/g

7. The catalyst p. 1, wherein the carrier further comprises a ceramic binder in the amount of 1 - 3% by weight relative to the components of aluminum oxide, expressed in VidZone 1 - 40% and the amount of the alkaline metal is 10 to 3000 parts per million by weight relative to the total weight of the catalyst based on metal.

9. The catalyst p. 8, wherein the alkaline metal chosen from the group consisting of potassium, rubidium, cesium, lithium and mixtures thereof.

10. The catalyst p. 1, characterized in that it further comprises a promoting amount of rhenium.

11. The catalyst according to p. 10, characterized in that it further comprises copromotor rhenium selected from the group consisting of sulfur, molybdenum, tungsten, chromium and mixtures thereof.

12. The method of receiving media for catalyst under item 1, which includes stages a) formation of a mixture containing (i) at least one component is aluminum oxide with an average particle size of 3 to 8 μm and an average crystallite size of 0.4 - 4 μm in a quantity sufficient to provide about 40 to 95% by weight of alpha alumina in the carrier, (ii) hydrogenated precursor of aluminium oxide in the form of a Sol and/or gel is possible with the introduction of the seed in a quantity sufficient to provide 5 - 60% by weight of the total weight of alumina in the catalyst carrier, (iii) burnable material in an amount of 5 to 40% relative to the weight-okida aluminia the required type; (C) firing to convert the precursor of aluminium oxide-aluminium oxide with obtaining a carrier for catalyst, in which particles of aluminum oxide with an average size of 3 to 8 μm and a crystallite size of 0.4 - 4 μm are distributed in a matrix of aluminum oxide obtained from material predecessor.

13. The method according to p. 12, characterized in that the precursor of aluminium oxide in the carrier comprises boehmite.

14. The method according to p. 12, characterized in that the precursor of aluminium oxide in the medium additionally comprises alumina trihydrate.

15. The method according to p. 12, characterized in that the precursor of aluminium oxide is administered as a dose-alumina with particle size less than 1 μm, taken in an amount of 0.2 to 5% by weight relative to the total weight of aluminum oxide, defined in the form of aluminum oxide in the catalyst carrier.

16. The method according to p. 12, wherein the extrudable mixture is added to the titanium oxide in the amount of 0.05 - 1% by weight relative to the total weight of the aluminum oxide in the composition, expressed in the form of aluminum oxide.

17. The method according to p. 12, wherein the extrudable mixture of a ceramic binder in the amount of 1 - 3% by weight to

 

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FIELD: hydrocarbon conversion catalysts.

SUBSTANCE: catalyst for generation of synthesis gas via catalytic conversion of hydrocarbons is a complex composite composed of ceramic matrix and, dispersed throughout the matrix, coarse particles of a material and their aggregates in amounts from 0.5 to 70% by weight. Catalyst comprises system of parallel and/or crossing channels. Dispersed material is selected from rare-earth and transition metal oxides, and mixtures thereof, metals and alloys thereof, period 4 metal carbides, and mixtures thereof, which differ from the matrix in what concerns both composition and structure. Preparation procedure comprises providing homogenous mass containing caking-able ceramic matrix material and material to be dispersed, appropriately shaping the mass, and heat treatment. Material to be dispersed are powders containing metallic aluminum. Homogenous mass is used for impregnation of fibrous and/or woven materials forming on caking system of parallel and/or perpendicularly crossing channels. Before heat treatment, shaped mass is preliminarily treated under hydrothermal conditions.

EFFECT: increased resistance of catalyst to thermal impacts with sufficiently high specific surface and activity retained.

4 cl, 1 tbl, 8 ex

FIELD: petroleum processing catalysts.

SUBSTANCE: invention provides reforming catalyst containing Pt and Re on oxide carrier, in particular Al2O3, wherein content of Na, Fe, and Ti oxides are limited to 5 (Na2O), 20 (Fe2O3), and 2000 ppm (TiO2) and Pt is present in catalyst in reduced metallic state and in the form of platinum chloride at Pt/PtCl2 molar ratio between 9:1 and 1:1. Contents of components, wt %: Pt 0.13-0.29, PtCl2 0.18-0.04, Re 0.26-0.56, and Al2O3 99.43-99.11. Preparation of catalyst comprises impregnation of alumina with common solution containing H2PtCl6, NH4ReO4, AcOH, and HCl followed by drying and calcination involving simultaneous reduction of 50-90% platinum within the temperature range 150-550оС, while temperature was raised from 160 to 280оС during 30-60 min, these calcination conditions resulting in creation of reductive atmosphere owing to fast decomposition of ammonium acetate formed during preparation of indicated common solution.

EFFECT: increased catalytic activity.

2 cl, 1 tbl, 3 ex

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