Method of improving selectivity of catalyst and a olefin epoxidation process

FIELD: industrial organic synthesis catalysts.

SUBSTANCE: method of improving selectivity of highly selective epoxidation catalyst on support containing silver in amount at most 0.19 g per 1 m2 of the support surface area comprises bringing catalyst or catalyst precursor containing silver in cationic form into contact with oxygen-containing raw material at catalyst temperature above 250°C over a period of time more than 150 h, after which catalyst temperature is lowered to at most 250°C. Olefin epoxidation process comprises bringing above-described supported catalyst or catalyst precursor into contact with oxygen-containing raw material at catalyst temperature above 250°C over a period of time more than 150 h, after which catalyst temperature is lowered to at most 250°C and catalyst is brought into contact with raw material containing olefin and oxygen.

EFFECT: increased selectivity of catalyst.

12 cl, 3 tbl, 12 ex

 

The technical FIELD TO WHICH the INVENTION RELATES.

This invention relates to a method of improving the selectivity highly selective epoxidation catalyst. This invention also relates to a method for the epoxidation of an olefin comprising the specified method in accordance with this invention.

The LEVEL of TECHNOLOGY

It has long been known catalytic epoxidation of olefins using a silver catalyst on a carrier, providing the corresponding olefin oxide. Known catalysts based on silver provide for the production of olefin oxides with deliberately low selectivity. For example, when using the known catalysts for the epoxidation of ethylene selectivity towards ethylene oxide, expressed as fraction of converted ethylene, does not reach values above limit average of 6/7 or of 87.5 mol.%. Therefore, the specified limit for a long time was taken for theoretical maximum selectivity of this reaction, based on the stoichiometry of the following reaction equations:

7C2H4+6O2=>6S2H4O+2SD2+2H2About

cf. Kirk-Othmer''s Encyclopedia of Chemical Technology, 3rded., Vol.9, 1980, p.445.

The selectivity to a large extent on the economic attractiveness of the process of epoxidation. For example, a one percent St is Ksenia selectivity of the epoxidation process can significantly reduce annual operating costs of big enterprises to obtain ethylene oxide.

The olefin oxide produced in the epoxidation process may be subjected to contact with water, alcohol or amine to obtain 1,2-diol, a simple ester 1,2-diol or alkanolamine. Thus, 1,2-diols, ethers, 1,2-diol and alkanolamine can be obtained through the implementation of the multi-stage process involving epoxidation of olefins and the conversion of the obtained olefin oxide with water, alcohol or amine. Any improvement in the selectivity of the epoxidation process can also significantly reduce annual operating costs for the entire process of producing 1,2-diol, a simple ester 1,2-diol or alkanolamine.

Modern epoxidation catalysts based on silver are highly selective for obtaining the olefin oxide. When using modern catalysts for the epoxidation of ethylene selectivity towards ethylene oxide can reach values exceeding the specified limit 6/7 or 85,7 mol.%. Such highly selective catalysts include, in addition to silver, which improves the selectivity of the alloying additive, which may be selected from rhenium, molybdenum, tungsten and compounds forming nitrates or nitrites, cf., for example, US-A-4761394 and US-A-4766105.

The INVENTION

The present invention relates to a method for improving the selectivity vysokoselektivnye the epoxidation catalyst on a carrier, containing silver in an amount of at most 0,19 g / m2the surface area of the carrier, which method includes:

- reduction catalyst or its precursor containing the silver in cationic form in the contact with oxygen-containing feedstock at a temperature of the catalyst above 250°C for up to 150 hours, and

further lowering the temperature of the catalyst to a value of at most 250°C.

This invention also relates to a method for epoxidation of olefins, including:

the bringing into contact of highly selective epoxidation catalyst on a carrier containing silver in an amount of at most 0,19 g / m2the surface area of the carrier or catalyst precursor containing the silver in cationic form, with oxygen-containing feedstock at a temperature of the catalyst above 250°C for up to 150 hours, and

further lowering the temperature of the catalyst to a value of at most 250°and bringing the catalyst into contact with a product containing olefin and oxygen.

This invention also relates to a method for producing 1,2-diol, a simple ester 1,2-diol or alkanolamine, including the conversion of the olefin oxide into the 1,2-diol, a simple ether 1,2-diol or alkanolamine, according to which the olefin oxide is produced by way epoxidation of olefin in accordance the present invention.

DETAILED description of the INVENTION

In accordance with this invention, the selectivity highly selective epoxidation catalyst can be improved by heat treatment of the catalyst in the presence of oxygen at temperatures generally above normal initial operating temperature of the catalyst. This is unexpected in light of the prior art. For example, in accordance with US-And-5646087 it is necessary to avoid the presence of oxygen when exposed to high temperature at the catalyst on the basis of silver; it was also suggested that at temperatures 250°and higher oxygen absorbed in significant quantities in the weight of the silver, where it has a negative effect on the characteristics of the catalyst.

Heat treatment, likely leading to a slight decline in catalyst activity, which requires a slightly higher operating temperature during normal use of the catalyst. The higher temperature will often lead to reduced service life of the catalyst due to its more rapid contact sintering. So (without being bound to any theory), it is preferable to avoid such heat treatment of the catalysts with a high density of silver on the surface of the carrier, i.e. the quantity of silver relative is on the surface area of the carrier, to reduce the level of contact sintering during the application of catalysts.

The catalyst may be subjected to heat treatment before its first use in the epoxidation process, when the heat treatment temperature of the catalyst can be reduced to a level that is appropriate, for example, for storage of the catalyst before its use in the epoxidation process. Alternatively, heat treatment may be subjected to the catalyst already used in the epoxidation process, the temperature of the catalyst can then be reduced to a level that is appropriate for carrying out the process of epoxidation.

In this description a highly effective catalyst for the epoxidation on silver-base in General is a catalyst, which when used for gas-phase epoxidation of ethylene directly after the receipt has a theoretical selectivity at zero oxygen conversion, S0comprising at least 6/7 or 85.7 percent. More specifically, this theoretical selectivity can be obtained when the reaction temperature 260°C. the Value of S0for a given catalyst can be determined by use of a catalyst, in particular at a temperature of 260°With, in the interval srednica the new volume of the gas velocity, resulting in an interval of values of selectivity and conversion of oxygen corresponding to the interval used average hourly volumetric velocity of gas use. Found values of selectivity then extrapolate back to theoretical selectivity at zero oxygen conversion, S0. In this description, the selectivity represents the proportion of olefin converted with obtaining the olefin oxide.

In General, highly selective epoxidation catalyst on the basis of silver is a catalyst on the carrier. The carrier can be selected from a wide range of inert materials carriers. Such materials carrier can be a natural or artificial inorganic materials include silicon carbide, clays, pumice, zeolites, charcoal and carbonates of alkaline earth metals such as calcium carbonate. Preferred are refractory materials-media such as aluminum oxide, magnesium oxide, zirconium dioxide and silicon dioxide. The most preferred material carrier is α-aluminum oxide.

The carrier is preferably porous and has a maximum surface area of 20 m2/g, in particular from 0.1 to 20 m2/g, more preferably from 0.5 to 10 m2/g, and most preferably from 1 to 5 m2 /, According to this description, the surface area measured by the BET method described by Brunauer, Emmet and Teller in J. Am. Chem. Soc. 60 (1938), 309-316.

The preferred carrier is alumina, providing highly selective catalysts based on silver with improved performance from the standpoint of selectivity, activity and life, has a surface area of at least 1 m2/g, and the size distribution of pores, which pores with a diameter in the range from 0.2 to 10 μm represent at least 70% of the total volume of pores together provide a pore volume of at least 0.25 ml/g based on the mass of the carrier. The size distribution of the pores is preferably such that pores with diameters less than 0.2 μm is from 0.1 to 10% of the total pore volume, in particular from 0.5 to 7% of the total pore volume; the pores with a diameter in the range from 0.2 to 10 μm represent from 80 to 99.9% of the total pore volume, in particular from 85 to 99% of the total pore volume; and the pores of diameter greater than 10 μm represent from 0.1 to 20% of the total pore volume, in particular from 0.5 to 10% of the total pore volume. Pores with a diameter in the range from 0.2 to 10 μm, preferably comprise a pore volume of 0.3 to 0.8 ml/g, in particular from 0.35 to 0.7 ml/g surface Area media of choice is usually a maximum of 3 m2/g surface Area preferably has a range from 1.4 to 2.6 m2/year

More high the cue total pore volume is preferred due to a more efficient deposition of silver and other catalyst components on the carrier in the impregnation. However, at higher total pore volume of the carrier or its derived catalyst may have a lower resistance to crushing.

According to this description, the distribution of pore size and pore volume are measured by introducing mercury to pressure 3,0×108PA model Micromeretics Autopore 9200 (contact angle 130°, mercury with a surface tension 0,473 N/m adjusted for compression of mercury).

The preferred carrier is alumina typically includes α-aluminum oxide in the amount constituting at least 80, 90 or 95 wt.% α-aluminium oxide, for example, to 99.9 wt.%, in particular, up to 99 wt.%, per mass of catalyst. Usually the preferred carrier of aluminum oxide further includes a binder material on the basis of containing silicon dioxide composition comprising a crystallization inhibitor, which inhibits the formation of crystalline compositions containing silicon dioxide. Typically, the binder material provides receive coverage of the silicon dioxide on the surface of the carrier, which makes the surface of the carrier is more susceptible to added metal components. Binder material generally ranges from 1 to 15 wt.%, in particular, from 2 to 10 wt.%, per mass of catalyst. Containing silicon dioxide composition used as a binder material is material, usually have a basis of amorphous silicon dioxide, for example, a Sol of silicon dioxide, precipitated precipitated silicon dioxide, amorphous silicon dioxide or amorphous alkali metal silicate or alumina silicate. As a rule, containing silicon dioxide composition used as a binder material may additionally contain as major components of hydrated alumina, such as boehmite, gibbsite, boyera or diasporas, as well as crystallization inhibitor, e.g. a compound of an alkali metal, in particular, water-soluble salt such as sodium salt or potassium.

It was found that the characteristics of the catalyst can be improved by rinsing the media before settling on him the other ingredients of the catalyst in order to remove soluble residues. On the other hand, can also be successfully used nepomechie media. Can be used continuous method of washing medium hot demineralized water up until the electrical conductivity of the water flow will not decrease even more. A suitable temperature for demineralized water is from 80 to 100°With, for example, from 90 to 95°C. This method is described in US-B1-6368998, US-2002/0010094 A1 and WO-00/15333, given here as a reference.

In General, highly selective catalysts epoxidase the ia on the basis of silver include, in addition to silver, a metal of group IA and one or more improves the selectivity of alloying elements selected from rhenium, molybdenum and tungsten. Highly selective catalysts include silver, in an appropriate case, in the range from 10 to 500 g/kg, more preferably from 50 to 250 g/kg, of the total weight of the catalyst. The metals of group IA, and also improves the selectivity of the alloying additives may be present in amounts of from 0.01 to 500 mmol/kg per element (rhenium, molybdenum, tungsten, or a metal of group IA) of the total mass of the catalyst. The metal of group IA is preferably selected from lithium, potassium, rubidium and cesium. Rhenium, molybdenum or tungsten in a proper case may constitute the oxy-anions, for example, perrenate, molybdate, tungstate, in the form of a salt or acid.

Typically, the amount of silver relative to the surface area of the carrier is a maximum of 0.17 g/m2more often - as 0.15 g/m2in particular, most 0.12 g/m2more preferably a maximum of 0.1 g/m2. Under normal implementation of this invention, the quantity of silver relative to the surface area of the carrier often is at least 0.01 g/m2more often - at least 0.02 g/m2.

Particularly preferred are highly selective epoxidation catalysts based on silver, enabling the e rhenium in addition to silver. Such highly selective epoxidation catalysts based on silver is known from US-A-4761394 and US-A-4766105, given here as a reference. In a broad sense, they include silver, rhenium or compound, additional metal or its compound and, optionally, co-promoter of the rhenium, which may be selected from sulfur, phosphorus, boron and its compounds on the base material. More specifically, the additional metal selected from metals of groups IA, IIA group metals, molybdenum, tungsten, chromium, titanium, hafnium, zirconium, vanadium, thallium, thorium, tantalum, niobium, gallium and germanium and mixtures thereof. Additional metal is preferably selected from metals of group IA, such as lithium, potassium, rubidium and cesium, and/or of the metals of groups IIA, such as calcium and barium. Most preferred are lithium, potassium and/or cesium. If possible, as oxyanion in the form of salts or acids typically used rhenium, additional metal or rhenium co-promoter.

Preferred are the following amounts of components in these catalysts, designed as an integral part of the total mass of the catalyst:

from 10 to 500 g/kg of silver,

from 0.01 to 50 mmol/kg of rhenium,

from 0.1 to 500 mmol/kg of additional metal or metals, and, if available,

from 0.1 to 30 mmol/kg rhenium co-promoter or co-promoter.

Obtaining catalysts known in the art, while traditional methods can be used in this invention. Methods of preparation of the catalyst include a carrier impregnated compound of silver and other ingredients of the catalyst, and the implementation of recovery to obtain particles of metallic silver. These methods are described, for example, in US-A-4761394, US-A-4766105, US-A-5380697, US-A-5739075, US-B1-6368998, US-2002/0010094 A1, WO-00/15333, WO-00/15334 and WO-00/15335, given here as a reference.

This invention applies to new catalysts, as well as, for example, the catalyst used in the epoxidation process, or used catalysts, which remained for a long time without eating due to faulty installation.

This invention can also be applied to the catalyst precursor. Under the catalyst precursor is meant a composition on the media, including silver in unrestored, i.e. cationic form, and including additional components are required to obtain after recovery expected for highly selective catalyst. In this case, the recovery may be carried out during contact with raw materials, including oxygen, at a temperature of more than 250°C.

Although this invention can be implemented is found in many ways, preferred is its implementation in the form of a gas-phase process, i.e. the process in which the raw material is subjected to a contact in the gas phase with the catalyst present in the form of a solid material, usually in the form of a bulk layer, located in the reactor, for example, in a tubular reactor. In the production on an industrial scale, the amount of catalyst used in this invention is typically at least 10 kg, such as at least 20 kg, often 102up to 107kg, usually from 103up to 106kg. Usually, this process is carried out as a continuous process. Typically, the reactor is equipped with a heat exchanger for heating or cooling of the catalyst. In this description of the raw material is a composition subjected to contact with the catalyst. According to this description, the temperature of the catalyst or the temperature of the catalyst layer is the weighted average temperature of the catalyst particles.

When using the new catalysts in some cases, before the implementation of the present invention may be useful pre-processing of these catalysts by exposure to high temperature by using purifying inert gas passed over the catalyst. The cleaning gas is, for example, nitrogen or Argo is, or mixture, including nitrogen and/or argon. Under the influence of high temperature catalyst substantial part of the organic nitrogen compounds that could be used to obtain catalysts, turns into a nitrogen-containing gases that are captured in the gas stream and removed from the catalyst. In addition, the catalyst can be removed all the moisture. As a rule, after loading the catalyst into the reactor the temperature of the catalyst was raised to the level of 200 to 250°With heater and above the catalyst pass the gas stream. Used catalysts may require or not require the use of cleansing gas, but the latter can often be applied. This method is described in detail in US-A-4874879, given here as a reference.

In accordance with this invention, the catalyst is treated, subjecting it to contact with an oxygen-containing feedstock at a temperature of more than 250°during the period of time up to 150 hours; this treatment in this description are referred to as "thermal treatment". As a rule, can be used in any temperature above 250°C, preferably at least 255°With, for example, up to 320°typically up to 300°C, preferably up to 280°C. the Duration of heat treatment is usually at least 0.5 hours, predpochtitel is but from 1 to 50 hours, in particular from 2 to 40 hours. The raw materials used for the heat treatment may be any oxygen-containing raw materials such as pure oxygen, or include additional components that are inert or not inert in the prevailing conditions. Raw materials in an appropriate case, is a mixture of oxygen with an inert gas, such as argon, helium and nitrogen, or a saturated hydrocarbon. Such mixtures may include, for example, air, oxygen-enriched air or mixture of air/methane. The amount of oxygen in the raw material is preferably from 1 to 30 vol.%, in particular, from 2 to 25 vol.%, from the total mass of raw materials. Inert and non-inert components can be selected among the components of the raw material for the process described below epoxidation and may be present in amounts specified below in the form of intervals. For example, the raw materials may include olefin, the olefin, at least partially, into corresponding epoxide, and in this case, the heat of formation of olefin oxide contributes to the achievement and adjustment of the desired temperature. Another advantage of using the olefin during heat treatment is that the improvement in catalyst selectivity can be controlled by controlling the degree of conversion of the olefin, for example, during a continuous process, the stabilisation of the speed reduction means, improved selectivity is nearing completion. During heat treatment it may be appropriate to use a lower oxygen concentration and lower concentration of olefin in the feedstock as compared with the composition of the raw materials for the further stages of the process during normal receipt of the olefin oxide. Lower oxygen concentration and a lower concentration of olefin in the feedstock can reduce the rate of conversion of oxygen, which contributes to better prevent the formation of hot spots in the catalyst, making the process more easily controlled.

Thus, during thermal processing of raw materials can include, in addition to oxygen, olefin, carbon dioxide, inert gas, saturated hydrocarbons and/or reaction modifiers, such as an organic halide compound or nitrate or nitratebased connection. However, during the heat treatment, the presence of one or more of these additional components in raw materials is not considered essential to this invention.

Heat treatment is usually carried out at an absolute pressure of from 1000 to 4000 kPa. When carrying out this stage in the form of a gas-phase process that includes a bulk layer of catalyst, interval GSHV (hourly average volumetric gas flow rate) is preferably from 1500 to 10000 nl/(l·h is from). GSHV or hourly average volumetric gas flow rate represents a unit volume of gas at normal temperature and pressure (0°C, 1 ATM, i.e. 101.3 kPa)passing through a unit volume of the bulk layer of catalyst per hour.

After the heat treatment temperature of the catalyst to reduce the temperature of maximum 250°With, in particular, to the temperature of maximum 245°C.

When carrying out this heat treatment in a separate process, i.e. which is the stage of the epoxidation process, the temperature of the catalyst after the heat treatment can be lowered to a temperature suitable for storage of the catalyst, for example, component from 0 to 50°With, in particular, from 10 to 40°C. After storage of the catalyst may be used in the epoxidation process.

It is advisable to implement the heat treatment in the form of phase epoxidation process, the raw materials for thermal processing may include at least oxygen and olefin, and as a reaction product is formed corresponding olefin oxide. Thermal treatment may be included in the process of epoxidation on any phase of this process, for example, at the beginning or entrance of the regular receipt of the olefin oxide. In this case, the heat treatment requires a higher temperature catalysis is the Torah compared to a normal temperature of use, followed by lowering the temperature to a level which is desirable as the operating temperature of the catalyst.

The following description relates to the epoxidation process that includes, as one of its stages, this heat treatment. It also refers to the process of epoxidation in which used catalyst is previously subjected to a heat treatment. The epoxidation process may be carried out using methods known in the art. Such methods are described, for example, in US-A-4761394, US-A-4766105, US-B1-6372925, US-A-4874879 and US-A-5155242, and is provided here as a reference.

Olefin, which can be used in the epoxidation process may be any olefin, such as an aromatic olefin, for example, styrene, or diolefin, whether or not containing conjugated double bonds, for example, 1,9-decadiene or 1,3-butadiene. Typically, the olefin is monoolefins, for example, 2-butene or isobutene. The olefin preferably is a mono-α-olefin, such as 1-butene or propylene. The most preferred olefin is ethylene.

The epoxidation process may be based on the use of air or oxygen, see Kirk-Othmer''s Encyclopedia of Chemical Technology, 3rded., Vol.9, 1980, pp.445-447. In the method based on the use of air as a source of oxidizer, use air or obog is placed in an oxygen, while in the processes based on the use of oxygen as the source of oxidant is used, the oxygen of high purity (>95 mol.%). Currently working mostly plants for epoxidation is based on the use of oxygen, which is also the preferred embodiment of the present invention.

Oxygen is usually used at a concentration to avoid ignition. The oxygen concentration in the raw material can be adjusted by changing the concentration of olefin in such a way as to remain outside the regime of ignition. Safe working periods depend, along with the composition of the raw materials from the epoxidation conditions, such as temperature and pressure of the catalyst.

The reaction modifier may be present in raw materials for improving the selectivity and suppression of undesirable oxidation of ethylene or of ethylene oxide to carbon dioxide and water with respect to the desired formation of ethylene oxide. As a reaction modifier can be used in many organic compounds, especially organic halide compounds (cf., for example, EP-A-352850, US-A-4761394 and US-A-4766105, given here as a reference). Can also be used organic or inorganic nitrogen compounds such as nitrogen oxides, hydrazine, hydroxylamine or MIAC, however, they, as a rule, are less preferred. It is believed that the technological conditions of the epoxidation process nitrogen-containing reaction modifiers are precursors of nitrates or nitrites, i.e. the so-called nitrate or nitratebased compounds (cf., for example, EP-A-3642 and US-A-4822900, given here as a reference).

The organic halide compound is, in particular, organic bromide, more specifically, the organic chloride. Preferred organic halide compounds include chlorinated hydrocarbons or brominated hydrocarbons. More preferably, they are selected from the group comprising methyl chloride, ethylchloride, ethylene dichloride, ethylenedibromide, vinyl chloride or a mixture thereof. The most preferred reaction modifiers are ethylchloride and ethylene dichloride.

Despite the fact that organic halide compound may initially be submitted in the form of a single connection, in contact with the catalyst may be formed by a variety of compounds that act as reaction modifier, which may be present in raw materials during recycling. For example, when using ethylchloride in the process using ethylene oxide raw materials in practice may contain ethylchloride, vinyl chloride, ethylene dichloride and ethylchloride.

In various embodiments, as reaction modifiers together with an organic halide compound, in particular, organic chloride, is used, among other things, nitrate or nitratebased connection, for example, nitrogen oxides and/or organic nitrogen compounds. Suitable nitrogen oxides have the General formula of NOxwhere x, denotes the ratio of the number of oxygen atoms to the number of nitrogen atoms, a has a value from 1 to 2. Such oxides include, for example, NO, N2O3and N2O4. Suitable organic nitrogen compounds are nitro compounds, nitroso compounds, amines, nitrates and nitrites, for example, nitromethane, 1-nitropropane or 2-nitropropane. Can also be used hydrazine, hydroxylamine or ammonia.

Raw materials may include one or more optional components, such as carbon dioxide, inert gases and saturated hydrocarbons. Carbon dioxide is a by-product of the epoxidation process. However, carbon dioxide has generally had a negative effect on the activity of the catalyst, therefore, high concentrations of carbon dioxide usually avoid. The inert gas may represent, for example, nitrogen or argon, or their mixture. Suitable saturated hydrocarbons are propane and cyclopropane, in particular, methane and ethane. On yennie hydrocarbons can be added to the raw material to improve the Flammability limit of oxygen.

Typically, in the initial phase of the process of epoxidation temperature of the catalyst may range from 180 to 250°C, more typically from 200 to 245°C. These temperatures are particularly suitable, if the catalyst is not yet subjected to a significant extent associated with aging deterioration of properties. Such aging is manifested in a decrease in catalyst activity. By reducing the activity of the catalyst temperature can be increased to compensate for the decreased activity. The temperature of the catalyst ultimately can be increased to values above 250°With, for example, to a temperature of 325°Since, as a rule, from 270 to 300°C. In General, the temperature of the catalyst can be increased until then, until it becomes undesirable high, and from this time believe that the service life of the catalyst is over and he needs to be replaced.

Typically, the concentration of olefin in the feedstock is a maximum of 80 mol.% the total mass of raw materials. This concentration is preferably from 0.5 to 70 mol.%, in particular, from 1 to 60 mol.%, from the total mass of raw materials. If desired, the concentration of the olefin can be increased in the continuation of the life of the catalyst, which may be increased selectivity on the phase of operation when the catalyst was old (cf. US-B1-6372925, given here as a reference).

Ka is the rule, the oxygen concentration is from 1 to 15 mol.%, more specifically, 2 to 10 mol.% from the total mass of raw materials.

As a rule, you should avoid the concentration of carbon dioxide in the raw material is higher than 10 mol.%, preferably above 5 mol.%, from the total mass of raw materials. The concentration of carbon dioxide can even be 1 mol.% and less of the total mass of raw materials. The inert gas may be present in raw materials in amounts of from 0.5 to 95 mol.% According to the method based on the use of air, inert gas may be present in the feedstock in an amount of from 30 to 90 mol.%, typically, from 40 to 80 mol.% According to the method based on the use of oxygen, inert gas may be present in raw materials in amounts of from 0.5 to 30 mol.%, as a rule, from 1 to 15 mol.% In the presence of saturated hydrocarbons, they may be present in an amount up to 80 mol.% from the total mass of raw materials, in particular, to 75 mol.% Often they are present in amount comprising at least 30 mol.%, more often - at least 40 mol.%.

The reaction modifiers are generally effective when used in raw materials in small quantities, for example, to 0.1 mol.% from the total mass of raw materials, for example, from 0.01·10-4to 0.01 mol.%. In particular, when the olefin is an ethylene, the reaction modifier is preferably present in the raw materials in the amount of 0,05×10-4up to 50×10-4-4up to 30×10-4mol.%, from the total mass of raw materials. A suitable amount of the reaction modifier in raw materials can also be expressed in connection with the quantity of hydrocarbons present in the feedstock. The relative amount Q of the reaction modifier is the ratio of an effective molar quantity of active species present in the raw materials of the reaction modifier to an effective molar quantity present in the raw material hydrocarbon, and the data molar quantities are expressed in the same units, e.g., in mol.% from the total mass of raw materials.

When using as a reaction modifier compounds halogen, with the aim of determining the effective molar quantity of active species of the reaction modifier and the value of Q, the number of active species take attendance of halogen atoms, and when used as reaction modifier nitrate or nitratebased connection, the number of active species take attendance of nitrogen atoms. This implies, for example, that 1 mol of ethylene dichloride gives 2 mol of active particles, i.e. all the available chlorine atoms give active particles. On the other hand, the reaction modifiers, which are formations bromide, such as methyl chloride and methyl bromide are less sensitive therefore, it is believed that from 2 to 5 moles, in particular from 2.5 to 3.5 moles, preferably 3 moles of methyl compounds give 1 mol of active particles. This number can be set and confirmed by conventional experiments (without reference to theory) suggest that this number is higher, the less the capacity used methyl connections to split the considered heteroatom (for example, a halogen atom or nitrogen). Thus, for example, if the raw material includes a 2×10-4mol.% ethylchloride, 3×10-4mol.% vinyl chloride, 1×10-4% ethylene dichloride and 1.5×10-4mol.% of methyl chloride, it can be calculated that the effective molar quantity of active species of the reaction modifier is (2×10-4·1)+(3×10-4·1)+(1×10-4·2)+(1,5×10-4·1/3)=7,5×10-4mol.%.

In other words, the effective molar quantity of active particles present in the raw materials of the reaction modifier may be calculated by multiplying the molar quantity of each present in the raw materials of the reaction modifier factor and addition works, where each coefficient indicates the amount present active heteroatoms, in particular, halogen atoms and/or nitrogen molecule is used, the reaction modifier when iconographies, that the ratio of the reaction modifier, which represents a methyl compound can range from 1/5 to 1/2, more specifically, from 1/3,5 1/2,5, preferably 1/3.

The hydrocarbons present in the feedstock include olefin and all available saturated hydrocarbons. It is assumed that present in the raw hydrocarbons have the ability to delete/remove the reaction modifier from the surface of the catalyst, the level of this ability of various hydrocarbons may vary. To determine these differences (relative to ethylene) molar quantity of each of the hydrocarbons present are multiplied by a factor before the addition molar quantities for the determination of the effective molar quantity of hydrocarbons. In this specification, the coefficient is equal to 1 by definition; the coefficient for methane may be from 0.1 to 0.5 or less, for example, to 0, more preferably from 0.2 to 0.4; the ratio for ethane can be from 50 to 150, more preferably from 70 to 120; and the coefficient for higher hydrocarbons (i.e. containing at least 3 carbon atoms) may be from 10 to 10000, more preferably from 50 to 2000. These factors can be identified and confirmed by conventional experiments (without reference to theory) suggest that this ratio is higher, the IU is the more the ability of the used hydrocarbon to form radicals. Appropriate coefficients for methane, ethane, propane and cyclopropane, relative to ethylene, 0.3, 85, 1000 and 60, respectively. As an example, if the raw material consists of 30 mol.% ethylene, 40 mole% methane, of 0.4 mol.% ethane and 0.0001 mol.% propane, it can be calculated that the effective molar quantity of hydrocarbons is (30·1)+(40·0,3)+(0,4·85)+(0,0001·1000)=76,1 mol.%.

It should be noted that upon receipt of ethylene oxide from ethylene without the presence of additional hydrocarbons effective molar quantity of hydrocarbons is valid molar quantity, and that the addition of ethane or higher hydrocarbons to ethylene raw material makes a significant contribution to an effective molar quantity, while any added methane makes a relatively small contribution. In some embodiments, the ratio of methane could be mistaken for a 0, thus, the effect of methane can be ignored, for example, for convenience.

The appropriate values of Q are at least 1×10-6in particular, at least 2×10-6. The appropriate values of Q are as high as 100×10-6in particular, a maximum of 50×10-6.

At any time during the epoxidation, the value of Q may be adjusted to provide optimum selectivity relative to the formation of the oxide is of the olefin. In practice, the value of Q can be adjusted by changing the number present in the raw materials of the reaction modifier without changing the concentration of hydrocarbons in the raw materials.

As indicated above, during the epoxidation temperature of the catalyst can be increased, for example, in order to compensate for the decrease in activity associated with aging of the catalyst. Deviations from optimal selectivity caused by temperature change can be reduced or even prevented by adjusting the value of Q is proportional to the temperature change of the catalyst. Thus, if the temperature of the catalyst varies with T1to T2then the Q-value can be changed with Q1to, essentially, Q2according to the following formula:

Q2=Q1+B (T2-T1),

which means a constant factor in (°)-1having a value greater than 0. Appropriate values can be set and confirmed by conventional experiments. The value is usually from 0.01×10-6up to 1×10-6in particular, from 0.1×10-60.5×10-6. A suitable value is to 0.22×10-6in particular, when used in combination with the above numbers and the coefficients used for the illustrative calculations effective the Aulnay number of active species of the reaction modifier and effective molar quantity of hydrocarbons.

The process is preferably carried out at a temperature T1catalyst, by applying such a value of Q1to the selectivity of the formation of olefin oxide was optimal. In this case, the epoxidation process will continue, with optimal selectivity, but not necessarily when the selectivity calculated by the formula (I) using the temperature T2catalyst and, in fact, the values of Q2.

As indicated below, additional reaction conditions of the epoxidation process may be very different. The absolute inlet pressure in the reactor is usually from 100 to 4000 kPa. When the process of epoxidation in the form of a gas-phase process that includes a bulk layer of catalyst, GSHV is preferably from 1500 to 10000 nl/(l·hour). The process speed is preferably from 0.5 to 10 KMOL of olefin oxide produced on m3of catalyst per hour, in particular from 0.7 to 8 KMOL of olefin oxide produced on m3of catalyst per hour, for example, 5 KMOL of olefin oxide produced on m3of catalyst per hour. In this description, the process speed is the amount of olefin oxide produced per unit volume of catalyst per hour, and selectivity refers to the molar number of the olefin oxide produced relative to mo is inogo number of modified olefin.

Get the olefin oxide may be selected from coming out of the reactor using methods known in the art, for example, by absorbing the olefin oxide from the effluent from the reactor flow in water and, optionally, separation of the olefin oxide from the aqueous solution by distillation. At least part of the aqueous solution containing the olefin oxide may be used in the further process for the conversion of the olefin oxide into the 1,2-diol or a simple ester 1,2-diol.

The olefin oxide produced in the described process for the epoxidation can be converted into a 1,2-diol, a simple ether 1,2-diol or alkanolamine. Since the present invention offers a more attractive process to obtain the olefin oxide, it simultaneously offers a more attractive process, including the production of olefin oxide in accordance with this invention and further use of the obtained olefin oxide to obtain 1,2-diol, a simple ester of 1,2-diol and/or alkanolamine.

Transformation into a 1,2-diol or a simple ester 1,2-diol may include, for example, the interaction of the olefin oxide with water, preferably using an acid or basic catalyst. For example, to obtain a predominant amount of 1,2-diol and a smaller number of simple ether 1,2-diol, the olefin oxide may be subjected to usaimage the action with a tenfold molar excess amount of water in the liquid-phase reaction in the presence of an acid catalyst, for example, 0.5 to 1.0 wt.% sulfuric acid by weight of the total reaction mixture, at a temperature of 50-70°and an absolute pressure of 1 bar or in the gas-phase reaction at a temperature of 130-240°and an absolute pressure of 20-40 bar, preferably in the absence of catalyst. At lower water content the content of ester 1,2-diol in the reaction mixture increases. Thus obtained ethers, 1,2-diol can be simple fluids, triavir, tetraethyl or subsequent broadcast. Alternative ethers, 1,2-diol can be obtained by conversion of the olefin oxide with alcohol, in particular, a primary alcohol, such as methanol or ethanol, by replacing at least part of the water with alcohol.

The transformation in alkanolamine may include, for example, the interaction of the olefin oxide with ammonia. Can be used in anhydrous or aqueous ammonia, although usually applied anhydrous ammonia, contributing to obtaining monoalkanolamines. Methods that can be used for the conversion of olefin oxide in alkanolamine described, for example, in US-A-4845296, given here as a reference.

1,2-Diol and a simple ether 1,2-diol may have a very different industrial applications, for example, they can be used to produce food, beverages, tobacco and cosmetics, thermoplastic in which Kerov, systems-curable resins, detergents, heat transfer systems, etc. Alkanolamine may be, for example, used for processing (deodorizing) of natural gas.

Unless otherwise specifically mentioned in this description of organic compounds, such as olefins, 1,2-diols, ethers, 1,2-diol and the reaction modifiers, usually contain a maximum of 40 carbon atoms, typically a maximum of 20 carbon atoms, in particular a maximum of 10 carbon atoms, preferably up to 6 carbon atoms. According to this description, the intervals of the numbers of atoms of carbon (i.e. carbon number) include the number specified for the limits of the intervals.

The following examples illustrate the invention without limiting its scope.

Examples 1-4 (example 1 are shown for comparison, examples 2-4 in accordance with this invention)

Getting media

Media get by mixing the following ingredients:

1. 67,4 weight parts α-aluminium oxide with d50size 29 microns;

2. 29 parts by weight of α-aluminium oxide with d50size 3 microns;

3. 3 weight parts of aluminum oxide (boehmite);

4. to 0.5 weight parts of silicon dioxide (in the form of a stable ammonia Zola from silicon dioxide); and

5. of 0.1 weight part of sodium oxide (as sodium acetate).

The average particle size indicated in the given the Scripture as "d 50" and measured using particle size analyzer, Horiba LA900, mean particle diameter, which are equal to the spherical equivalent volume of particles greater than and less than the established average particle size. This method comprises dispersing particles using ultrasonic treatment, in which secondary particles are destroyed to primary particles. Such an ultrasonic processing continues until, until you stop changing the value of d50that usually requires a 5-minute audio processing using particle size analyzer, Horiba LA900.

To the resulting mixture add 5 wt.%, by weight of a mixture of vaseline, 9 wt.%, by weight of the mixture, the burnable material and 0.1 wt.%, by weight of a mixture of boric acid. Then add water (about 30 wt.% by weight of the mixture) in number, making the extrudable mixture, after which the mixture ekstragiruyut to obtain molded products in the form of hollow cylinders with a diameter of about 8 mm and a length of 8 mm and Then dried and calcined in a kiln at 1425°C for 4 hours in the air, receiving the carrier A. as to further procedures to obtain this media, they are described in US-A-5100859.

The surface area of the thus obtained carrier is 2.0 m2/g Total pore volume is of 0.41 ml/g, and the volume of pores having a diameter in the range is 0.2 to 10 μm, is 0.37 ml/g by weight of the substrate. The size distribution of pores: pores having a diameter in the range of <0.2 μm, is 5 vol.%, pores having a diameter in the range of 0.2-10 μm, up 92%, as pores having a diameter in the range of >10 μm, amount to 3% vol. of the total pore volume.

The media is subjected to washing with hot deionized water, following the method described in US-2002/0010094 A1, paragraph 0034. The dried carrier is then used to obtain a catalyst.

Obtaining catalyst

The main solution of silver oxalate amine was prepared as follows:

415 g of sodium hydroxide brand "pure" dissolved in 2340 ml of deionized water and the temperature adjusted to 50°C.

1699 silver nitrate high purity "Spectropure" dissolved in 2100 ml of deionized water and the temperature adjusted to 50°C.

To the silver nitrate solution slowly with stirring a solution of sodium hydroxide, maintaining the temperature of the solution at 50°Poluchennuyu the mixture is stirred for 15 minutes and then the temperature is reduced to 40°C.

From the precipitate, formed during mixing, remove the water and measure the conductivity of water containing sodium ions and nitrate. To a solution of silver again add a number of fresh deionized water equal to the remote number. The solution is stirred t is the treatment for 15 minutes at 40° C. the Procedure is repeated up until the conductivity of the remote water will not be less than 90 μs/see Then add 1500 ml of fresh deionized water. Portions of approximately 100 g add 630 g of high-purity dihydrate of oxalic acid. The temperature is maintained at 40°and the pH is maintained at the level above 7.8.

The resulting mixture to remove water, receiving highly concentrated, containing silver suspension. A suspension of silver oxalate is cooled to 30°C.

The temperature is not above 30°add 699 g of 92 wt.% Ethylenediamine (8 wt.% deionized water). The initial solution of the silver-amine-oxalate contains approximately 27-33 wt.% silver.

Solutions for impregnating receive, adding to the above samples from the original solution of silver-amine-oxalate aqueous solutions, including pre-set amount of lithium hydroxide, ammonium perrhenate, meta-tungstate ammonium hydroxide caesium (optional) and water. The specified number is determined in advance by calculation, based on the desired composition of the resulting catalyst.

The sample carrier obtained in accordance with the description given in the section "Obtaining carriers impregnated with a solution for impregnation and dried as follows. The sample carrier is placed in a vacuum with a pressure of 25 mm Hg for 1 minute when anatoy temperature. Then submit a solution for impregnation in the amount of approximately 1.6 g/g carrier, covering the media, and vacuum support at a pressure of 25 mm Hg for a further 3 minutes. Then the vacuum is removed and the excess solution impregnation removed from the catalyst precursor by centrifugation at 500 rpm./min for two minutes. Thereafter, the catalyst precursor is dried, exposing his shaking at 250°C for 5.5 minutes in the air stream. Thus obtained catalyst contains a 14.5 wt.% silver, 2.0 mmol/kg of rhenium, 2.0 mmol/kg of tungsten, 7.2 mmol/kg of cesium and 40 mmol/kg lithium, all of the components given in the calculation of the mass of the catalyst.

The catalyst test

Thus obtained catalyst was tested upon receipt of ethylene oxide from ethylene and oxygen. For this purpose samples of the crushed catalyst weight of 1.5, and 2.0 g placed in four U-shaped stainless steel tube. Tube immersed in a bath of molten metal (hot environment) at 180°and the ends of each tube connected to the gas flow. The gas mixture is passed through layers of catalysts once. A lot of the used catalyst and the flow rate of inlet gas adjusted so as to obtain the volumetric rate of gas 6800 nl/(l·hour). Absolute gas inlet pressure is 150 kPa. The composition of the mixture gas is adjusted so that it contained 25 vol.% ethylene, 7% vol. oxygen, 5% vol. carbon dioxide, 2,5 OBC/million ethylchloride, the rest is nitrogen.

The temperature of each of the layers of catalysts raise with a speed of 10°per hour to 225°and then the specified temperature regulate so that the content of ethylene oxide was 1.5% vol. in each of the streams leaving gas. For each layer of catalyst concentration ethylchloride in the gas mixture is 2.5 OBC/million so as to obtain optimal selectivity at constant concentration of ethylene oxide in the stream leaving gas. These conditions support for 100 hours, during which establishes the performance of the catalyst. Table I shows the performance of each catalyst, expressed in terms of temperature and selectivity, measured after a specified period of 100 hours. The higher temperature required to obtain certain content of ethylene oxide in the stream leaving gas, shows a lower activity of the catalyst.

Then, as shown in table I, through each layer of catalysts miss a different gas mixture, and the temperature of each layer of the catalyst is raised to 260°C for 24 hours. After this period of time again usloviam, used immediately before the increase of temperature and the temperature of each layer of catalysts regulate so that again to get the content of ethylene oxide and 1.5 vol.% in each of the streams leaving gas. For each layer of catalyst concentration ethylchloride in gas mixtures again bring to 1.5 OBC/million

In table I indicated temperature and the selectivity of each catalyst immediately after the re-establishment of concentration ethylchloride.

Table I
ExampleThe composition of the gas during the heat treatment at 260°Up to 24 hours at 260°After 24 hours at 260°
Temperature (°)Selectivity (mol.%)Temperature (°)Selectivity (mol.%)
1*)Only nitrogen22282,022384,4
2**)9,4 vol.% oxygen, 6,7% vol. carbon dioxide, balance nitrogen22482,024288,6
3**)9,4 vol.% oxygen, 6,7% vol. carbon dioxide, 0.5 parts about. on million ethylchloride, balance: nitrogen222 82,124289,3
4**)5,0% vol. ethylene, 7,0 vol.% oxygen 5,0% vol. carbon dioxide, ethylchloride ***), balance: nitrogen22483,024089,4
*) for comparison

**) in accordance with this invention

***) trace amounts, <0,1 OBC/million

Similar methods were also received and investigated other catalysts with obtaining similar results. Such catalysts include, for example, of 14.5 wt.% silver, 2.0 mmol/kg of rhenium, 6,0 mmol/kg of cesium and 40 mmol/kg of lithium; or a 14.5 wt.% silver, 2.0 mmol/kg of rhenium, 1.0 mmol/kg of tungsten, 7.2 mmol/kg of cesium and 40 mmol/kg lithium, all of the components given in the calculation of the mass of the catalyst.

Examples 5-8 (example 5 is shown for comparison, examples 6-8 in accordance with this invention)

Samples (1.5 to 2.0 g) crushed catalyst from examples 1-4 are placed in four U-shaped stainless steel tube. Tube immersed in a bath of molten metal (hot environment) at 180°and the ends of each tube connected to the gas flow. The gas mixture is passed through layers of catalysts once. A lot of the used catalyst and the flow rate gas inlet regulate in such a way as to receive a volume near the gas industry 6800 nl/(l· hour). The absolute gas pressure at the inlet is 1550 kPa.

According to examples 6, 7 and 8, the catalyst is first subjected to a preliminary treatment at 260°C for 4, 12 and 24 hours, respectively, a gas mixture of 17,5% vol. oxygen and 82.5% vol. of nitrogen. The temperature was then reduced to 225°and the composition of the gas mixture regulate so that it contained 25 vol.% ethylene, 7% vol. oxygen, 5% vol. carbon dioxide, 1,5 OBC/million ethylchloride and the rest is nitrogen. In example 5, the catalyst is not subjected to pre-processing.

The temperature of each of the layers of the catalysts increases with the speed of 10°With an hour to 255°and then the specified temperature regulate so that the content of ethylene oxide was 1.5% vol. in each of the streams leaving gas. For each layer of catalyst concentration ethylchloride in the gas mixture is 1.5 OBC/million so as to obtain optimal selectivity at constant concentration of ethylene oxide (1,5%) in the stream leaving gas. These conditions support during working 100 hours, during which establishes the performance of the catalyst.

The table shows the final temperature and the selectivity of each catalyst.

Table II
ExampleP is abolitionist (hrs.) at 260° The temperature of the catalyst (°)Selectivity(mole%)
5*)0226to 83.5
6**)4237and 88.8
7**)1224589,4
8**)2425289,8
*) for comparison

**) in accordance with this invention

Similar methods were also received and investigated other catalysts with obtaining similar results. Such catalysts include, for example, of 14.5 wt.% silver, 3.0 mmol/kg of rhenium, 3.0 mmol/kg of tungsten, 7.5 mmol/kg of cesium and 20 mmol/kg of lithium, all of the components given in the calculation of the mass of the catalyst.

Examples 9-12 (example 9 are shown for comparison, examples 10-12 in accordance with this invention)

Samples (1.5 to 2.0 grams) of crushed catalyst from examples 1-4 are placed in four U-shaped stainless steel tube. Tube immersed in a bath of molten metal (hot environment) at 180°and the ends of each tube connected to the gas flow. The gas mixture is passed through layers of catalysts once. A lot of the used catalyst and the flow rate of inlet gas adjust so that the floor is resolved to the volumetric rate of gas 6800 nl/(l.h). The absolute gas pressure at the inlet is 1550 kPa.

The gas mixture has the following composition: 25% vol. ethylene, 7% vol. oxygen, 5% vol. carbon dioxide, 2,5 OBC/million ethylchloride and the rest is nitrogen.

The temperature of each of the layers of the catalysts increases with the speed of 10°With an hour to 255°and then the specified temperature regulate so that the content of ethylene oxide was 1.5% vol. in each of the streams leaving gas. For each layer of catalyst concentration ethylchloride in the gas mixture is 2.5 OBC/million so as to obtain optimal selectivity at constant concentration of ethylene oxide in the stream leaving gas. These conditions support for 100 hours, during which establishes the performance of the catalyst.

According to examples 10, 11 and 12, the temperature of the layers of the catalysts then increased to 260°at 4, 12 and 24 hours, respectively, during which a layer of catalyst is passed a gas mixture containing 9,5% vol. oxygen, 6,8% vol. carbon dioxide and nitrogen (balance). Then reduce the temperature to 225°and the composition of the gas mixture regulate so that it contained 25 vol.% ethylene, 7% vol. oxygen, 5% vol. carbon dioxide, 1,5 OBC/million ethylchloride and the rest is nitrogen. In example 9 the composition and temperature of the gas mixture is not changed.

In table III of the criminal code which are final temperature and the selectivity of each catalyst.

Table III
ExampleDuration (hrs.) at 260°The temperature of the catalyst (°)Selectivity (mol%)
9*)023083,0
10**)423788,0
11**)12247to 89.5
12**)24242to 89.5
*) for comparison

**) in accordance with this invention

Examples 2-4, 6-8 and 10-12 (in accordance with this invention) compared with examples 1, 5 and 9 (comparative) show that after exposure to the catalyst containing oxygen gas at a high temperature such as 260°C, the catalyst exhibits improved selectivity when used in the normal process of epoxidation. Was established remarkably high selectivity, although the catalysts were used at a higher temperature, providing the same content of ethylene in the gas streams leaving the reactor. The proposed method of increasing the selectivity of the catalyst can be carried out in stages in the process of epoxidation, to the to, for example, in examples 2-4 and 10-12, or this method can be carried out before the process of epoxidation, as in examples 6-8.

1. Method for improving the selectivity highly selective epoxidation catalyst on a carrier containing silver in an amount of at most 0,19 g / m2the surface area of the carrier, and, in addition to silver, one or more increases the selectivity of alloying elements selected from rhenium, molybdenum and tungsten, comprising bringing the catalyst or its precursor containing the silver in cationic form, in contact with oxygen-containing feedstock at a temperature of the catalyst over 250°From within, at least, from 0.5 to 150 hours and then reducing the temperature of the catalyst to a value of at most 250°C.

2. The method according to claim 1, in which the catalyst contains media from the α-alumina having a surface area, comprising at least 1 m2/g, and the size distribution of pores, which pores with a diameter in the range from 0.2 to 10 μm represent at least 70% of the total pore volume and such pores together provide a pore volume average of at least 0.25 ml/g based on the mass media.

3. The method according to claim 1, in which the catalyst contains, in addition to silver, a metal of group IA and one or more enhancing the selectivity of the alloying EXT the wok, selected from rhenium, molybdenum and tungsten.

4. The method according to claim 3, in which the catalyst contains, in addition to silver, rhenium or compound, additional metal or its compound selected from group IA metals, group IIA metals, molybdenum, tungsten, chromium, titanium, hafnium, zirconium, thallium, thorium, tantalum, niobium, gallium and germanium and mixtures thereof, and, optionally, rhenium copromoter, which can be selected from one or more of the following compounds: sulfur, phosphorus, boron and their connection to the material.

5. The method according to claim 1, in which the catalyst contains media from the α-aluminium oxide, and a quantity of silver relative to the surface area of the carrier is at most 0.17 g/m2in particular, in the range of from 0.01 to 0.15 g/m2more specifically , in the range from 0.02 to 0.12 g/m2.

6. The method according to claim 5, in which the catalyst contains silver in an amount of from 50 to 250 g/kg of the total mass of the catalyst and the carrier has a surface area of from 1 to 5 m2/year

7. The method according to claim 1, in which the catalyst leads in contact with oxygen-containing feedstock in an amount of from 1 to 30 vol.% from the total mass of the raw material at a temperature in the range of from more than 250 to 320°C.

8. The method according to claim 1, in which in addition to oxygen raw materials include olefin.

9. The method of epoxidation of an olefin comprising bringing kontaktverwaltung catalyst for epoxidation on the media, containing silver in an amount of at most 0,19 g / m2the surface area of the carrier, and, in addition to silver, one or more increases the selectivity of alloying elements selected from rhenium, molybdenum and tungsten, or catalyst precursor containing the silver in cationic form, with oxygen-containing feedstock at a temperature of the catalyst over 250°From within, at least, from 0.5 to 150 hours and then reducing the temperature of the catalyst to a value of at most 250°and bringing the catalyst into contact with a product containing olefin and oxygen.

10. The method according to claim 9, in which the olefin is an ethylene.

11. The method according to claim 9, in which the raw material containing the olefin and the oxygen, additionally contains as a reaction modifier, organic chloride and, optionally, nitrate or nitratebased connection.

12. Method for producing 1,2-diol, a simple ester 1,2-diol or alkanolamine, including the production of olefin oxide by the method of epoxidation of olefin according to claim 9 and

the conversion of the olefin oxide into the 1,2-diol, a simple ether 1,2-diol or alkanolamine.



 

Same patents:

FIELD: organic synthesis.

SUBSTANCE: invention relates to olefin epoxidation method and methods for preparing 1,2-diol or 1,2-diol ether, or alkylamine including conversion of olefin oxide into 1,2-diol or 1,2-diol ether, or alkylamine. Olefin epoxidation method comprises: (a) preliminarily impregnating high-selectivity silver-based epoxidation catalyst with organohalogen compound; (b) passing, over preliminarily impregnated catalyst, a material free of organohalogen compound or containing it in concentration not higher than 2·10-4 mol % (calculated for halogen) over a period of time from 15 h to 200 h; and (c) contacting resulting catalyst with material containing olefin, oxygen, and organohalogen compound wherein concentration of organohalogen compound is by at least 0.2·10-4 mol % higher than that of compound in step (b). Preparation of 1,2-diol, 1,2-diol ether, or alkylamine is also described.

EFFECT: optimized process parameters.

13 cl, 1 tbl

FIELD: organic chemistry.

SUBSTANCE: claimed method includes interaction of raw materials containing olefin, oxygen and reaction modifying agent in presence high selective silver-based catalyst at reaction temperature of T. Relative amount of reaction modifying agent is Q, wherein Q is ratio of effective molar amount of active sites of reaction modifying agent representing in raw materials to effective molar amount of hydrocarbon representing in raw materials. Epoxydation process is carried out in the first process phase wherein T=T1 and Q=Q1. Further process is carried out in the second process phase at T=T2 and Q=Q2, wherein T2 and Q2 are differ from T1 and Q1. Q2 is calculated according to equation Q2 = Q1 + B(T2 - T1) wherein B represents constant more than 0. Also disclosed are method for production of 1,2-diol or 1,2-diol ether; reaction system used in investigation; computer program product for calculations and computer system including said program product and information processing system.

EFFECT: improved method and system for olefin epoxydation.

22 cl, 2 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for the epoxidation reaction of olefin. Method involves interaction of the parent olefin-containing raw, oxygen and an agent modifying reaction in the presence of a silver-base catalyst. Agent modifying the reaction presents in the relative amount Q that represents the ratio of effective molar amount of active parts of reaction modifying agent presenting in the parent raw to the effective molar amount of hydrocarbons presenting in the parent raw. Proposed method involves the following steps: interaction in the first stage of process wherein Q values are equal to Q1 and the following interaction in the second step of process wherein the composition of the parent raw differs from composition of the parent raw used in the first step of process and Q value is equal to Q2 wherein value Q2/Q1 = 0.5-1.5. Also, invention relates to a method for synthesis of 1,2-diol or 1,2-diol ether, system for realization of method, the end product and a computer system suitable for using with proposed method.

EFFECT: improved method of synthesis.

20 cl, 2 ex

FIELD: organic synthesis catalysts.

SUBSTANCE: invention relates to creating carriers for catalysts used in epoxidation of olefins and provides catalyst containing at least 95% α-alumina with surface area 1.0 to 2.6 m2/g and water absorption 35 to 55%, and which has pores distributed such that at least 70% pore volume is constituted by pores 0.2 to 10 μm in diameter, wherein pores with diameters 0.2 to 10 μm form volume constituting at least 0.27 ml/g of carrier. Also described is a method for preparing catalyst carrier, which envisages formation of mixture containing 50-90% of first α-alumina powder with average particle size (d50) between 10 and 90 μm; 10-50% (of the total weight of α-alumina) of second α-alumina powder with average particle size (d50) between 2 and 6 μm; 2-5% aluminum hydroxide; 0.2-0.8% amorphous silica compound; and 0.05-0.3% alkali metal compound measured as alkali metal oxide, all percentages being based on total content of α-alumina in the mixture. Mixture of particles is then calcined at 1250 to 1470°C to give target carrier.

EFFECT: increased activity of catalyst/carrier combination and prolonged high level of selectivity at moderated temperatures.

21 cl, 3 tbl

FIELD: industrial organic synthesis catalysts.

SUBSTANCE: invention provides catalyst for oxidation of ethylene into ethylene oxide, which catalyst contains no rhenium and no transition metals and comprises up to 30% silver on solid support and promoter combination mainly consisted of (i) component containing alkali metal on amount from 700 to 3000 ppm of the mass of catalyst and (ii) component containing sulfur in amount from 40 to 100% by weight of amount required to form alkali metal sulfate and, optionally, a fluorine-containing component in amount from 10 to 300 ppm of the mass of catalyst. Ethylene oxide is produced via reaction of ethylene with molecular oxygen in presence of above-defined catalyst.

EFFECT: increased selectivity of catalyst.

9 cl, 3 tbl

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for vapor-phase oxidation of ethylene to ethylene oxide. Method involves interaction of ethylene and oxygen in the presence of silver-base highly selective catalyst. On the onset stage of process fresh catalyst is used and on the additional stage of process when cumulative productivity enhances 0.01 kT of ethylene oxide per m3 of catalyst by ethylene oxide the concentration of ethylene is increased in the reaction mixture. Also, invention relates to a method for using ethylene oxide for preparing 1,2-ethanediol or corresponding 1,2-ethanediol ether involving conversion of ethylene oxide to 1,2-ethanediol or 1,2-ethanediol ether wherein ethylene oxide has been prepared by this method for producing ethylene oxide.

EFFECT: enhanced selectivity, enhanced activity of catalyst.

12 cl, 4 dwg, 1 tbl

The invention relates to a method for selection of the ethylene oxide absorption from the gas mixture obtained in the oxidation of ethylene with oxygen in the presence of silver-containing catalyst, and can be used in the production of ethylene oxide

FIELD: inorganic synthesis catalysts.

SUBSTANCE: passivation of ammonia synthesis catalyst is accomplished via consecutively treating reduced iron catalyst with oxidant at elevated temperatures and process flow rates. Treatment of catalyst with oxidant is commenced with water steam or steam/nitrogen mixture at 150-300°C while further elevating temperature by 50-200°C, after which temperature is lowered to 150-300°C, at which temperature water steam or steam/nitrogen mixture is supplemented by air and treatment of catalyst is continued with resulting mixture while elevating temperature by 50-200°C followed by reduction of catalyst temperature in this mixture to 150-300°C and cooling of catalyst with nitrogen/oxygen mixture at initial ratio not higher than 1:0.1 to temperature 30°C and lower until nitrogen/oxygen mixture gradually achieves pure air composition.

EFFECT: prevented self-inflammation of ammonia synthesis catalyst when being discharged from synthesis towers due to more full oxidation.

6 cl, 1 tbl, 5 ex

FIELD: carbon materials.

SUBSTANCE: invention relates to porous carbon materials and, more specifically, to carbon catalyst supports and sorbents. Preparation of catalyst support is accomplished by mixing carbon material with gaseous hydrocarbons at 750-1200°C until mass of carbon material increases by 2-2.5 times, after which resulting compacted material is oxidized, said initial carbon material being preliminarily demetallized carbon nanofibers.

EFFECT: increased sorption capacity of material.

1 tbl, 6 ex

FIELD: carbon materials.

SUBSTANCE: invention relates to porous carbon materials and, more specifically, to carbon catalyst supports and sorbents. Preparation of catalyst support is accomplished by treating carbon black with hydrocarbon gas at heating and stirring until mass of carbon material increases by 2-2.5 times, after which resulting compacted material is oxidized, said hydrocarbon gas being gas originated from liquid hydrocarbon electrocracking and said treatment being carried out at 400-650°C.

EFFECT: simplified technology.

1 tbl, 6 ex

FIELD: petroleum processing catalysts.

SUBSTANCE: catalyst containing platinum, rhenium, antimony, and chlorine on alumina are prepared by impregnation of carrier with aqueous solution of compounds of indicated elements, antimony being deposited as first or second component. Once antimony or platinum-antimony combination, or rhenium-antimony combination deposited, catalyst is dried at 130°C and then calcined in air flow at 500°C. Reduction of catalyst is performed at 300-600°C and pressure 0.1-4.0 MPa for 4 to 49 h. After deposition of antimony or two elements (platinum-antimony or rhenium-antimony) and drying-calcination procedures, second and third or only third element are deposited followed by drying and calcination. Final reduction of catalyst is accomplished in pilot plant reactor within circulating hydrogen medium at pressure 0.3-4.0 MPa and temperature up to 600°C for a period of time 12 to 48 h.

EFFECT: enhanced aromatization and isomerization activities of catalyst and also its stability.

2 cl, 1 tbl, 8 ex

FIELD: exhaust gas afterburning means.

SUBSTANCE: invention relates to catalytic neutralizer for treating internal combustion engine exhausted gases. Proposed catalyst is composed of catalytically active coating on inert ceramic or metallic honeycomb structure, wherein coating contains at least one platinum group metal selected from series including platinum, palladium, rhodium, and iridium on fine-grain supporting oxide material, said supporting oxide material representing essentially nonporous silica-based material including aggregates of essentially spherical primary particles 7 to 60 nm in diameter, while pH of 4% water dispersion of indicated material is below 6.

EFFECT: increased catalyst activity and imparted sufficient resistance to aggressive sulfur-containing components.

27 cl, 2 dwg, 7 tbl, 6 ex

FIELD: petroleum processing and catalysts.

SUBSTANCE: invention relates to catalyst for steam cracking of hydrocarbons, which catalyst contains KMgPO4 as catalyst component. Catalyst is prepared by dissolving KMgPO4 precursor in water and impregnating a support with resulting aqueous solution of KMgPO4 precursor or mixing KMgPO4 powder or its precursor with a metal oxide followed by caking resulting mixture. Described is also a light olefin production involving steam cracking of hydrocarbons.

EFFECT: increased yield of olefins, reduced amount of coke deposited on catalyst, and stabilized catalyst activity.

21 cl, 4 tbl, 14 cl

FIELD: hydrogenation-dehydrogenation catalysts.

SUBSTANCE: invention provides copper and silica-based catalyst containing 22.5-53.0% copper. Catalyst is prepared by reductive thermal decomposition of copper silicate in hydrogen flow at 380-450°C. catalyst is used in dihydroxyalkane production processes carried out at 180-200°C.

EFFECT: increased activity and selectivity of catalyst.

3 cl, 1 tbl, 8 ex

FIELD: gas treatment processes and catalysts.

SUBSTANCE: invention relates to catalyst for selectively oxidizing hydrogen sulfide to sulfur in industrial gases containing 0.5-3.0 vol % hydrogen sulfide and can be used at enterprises of gas-processing, petrochemical, and other industrial fields, in particular to treat Claus process emission gases, low sulfur natural and associated gases, chemical and associated petroleum gases, and chemical plant outbursts. Catalyst for selective oxidation of hydrogen sulfide into elementary sulfur comprises iron oxide and modifying agent, said modifying agent containing oxygen-containing phosphorus compounds. Catalyst is formed in heat treatment of α-iron oxide and orthophosphoric acid and is composed of F2O3, 83-89%, and P2O5, 11-17%. Catalyst preparation method comprises mixing oxygen-containing iron compounds with modifying agent compounds, extrusion, drying, and heat treatment. α-Iron oxide used as oxygen-containing iron compound is characterized by specific surface below 10 m2/g, while 95% of α-iron oxide have particle size less than 40 μm. Orthophosphoric acid is added to α-iron oxide, resulting mixture is stirred, dried, and subjected to treatment at 300-700°C. Hydrogen sulfide is selectively oxidized to elemental sulfur via passage of gas mixture over above-defined catalyst at 200-300°C followed by separation of resultant sulfur, O2/H2S ratio in oxidation process ranging from 0.6 to 1.0 and volume flow rate of gas mixture varying between 900 and 6000 h-1.

EFFECT: increased yield of elemental sulfur.

9 cl, 5 tbl, 9 ex

FIELD: petrochemical process catalysts.

SUBSTANCE: group of inventions relates to conversion of hydrocarbons using micro-mesoporous-structure catalysts. A hydrocarbon conversion process is provided involving bringing hydrocarbon raw material, under hydrocarbon conversion conditions, into contact with micro-mesoporous-structure catalyst containing microporous crystalline zeolite-structure silicates composed of T2O3(10-1000)SiO2, wherein T represents elements selected from group III p-elements and group IV-VIII d-elements, and mixture thereof, micro-mesoporous structure being characterized by micropore fraction between 0.03 and 0.40 and mesopore fraction between 0.60 and 0.97. Catalyst is prepared by suspending microporous zeolite-structure crystalline silicates having above composition in alkali solution with hydroxide ion concentration 0.2-1.5 mole/L until residual content of zeolite phase in suspension 3 to 40% is achieved. Thereafter, cationic surfactant in the form of quaternary alkylammonium of general formula CnH2n+1(CH3)3NAn (where n=12-18, An is Cl, Br, HSO4-) is added to resulting silicate solution suspension and then acid is added formation of gel with pH 7.5-9.0. Gel is then subjected to hydrothermal treatment at 100-150°C at atmospheric pressure or in autoclave during 10 to 72 h to produce finished product.

EFFECT: enlarged assortment of hydrocarbons and increased selectivity of formation thereof.

16 cl, 2 dwg, 2 tbl

FIELD: engineering of Fischer-Tropsch catalysts, technology for producing these and method for producing hydrocarbons using said catalyst.

SUBSTANCE: catalyst includes cobalt in amount ranging from 5 to 20 percents of mass of whole catalyst on argil substrate. Aforementioned substrate has specific surface area ranging from 5 to 50 m2/g. Catalyst is produced by thermal processing of argil particles at temperature ranging from 700 to 1300°C during period of time from 1 to 15 hours and by saturating thermally processed particles with cobalt. Method for producing hydrocarbon is realized accordingly to Fischer-Tropsch method in presence of proposed catalyst.

EFFECT: possible achievement of high selectivity relatively to C5+ at low values of diffusion resistance inside particles.

3 cl, 9 ex, 9 dwg

FIELD: structural chemistry and novel catalysts.

SUBSTANCE: invention provides composition including solid phase of aluminum trihydroxide, which has measurable bands in x-ray pattern between 2Θ=18.15° and 2Θ=18.50°, between 2Θ=36.1° and 2Θ=36.85°, between 2Θ=39.45° and 2Θ=40.30°, and between 2Θ=51.48° and 2Θ=52.59°, and has no measurable bands between 2Θ=20.15° and 2Θ=20.65°. Process of preparing catalyst precursor composition comprises moistening starting material containing silicon dioxide-aluminum oxide and amorphous aluminum oxide by bringing it into contact with chelating agent in liquid carrier and a metal compound; ageing moistened starting material; drying aged starting material; and calcining dried material. Catalyst includes carrier prepared from catalyst composition or catalyst precursor and catalytically active amount of one or several metals, metal compounds, or combinations thereof. Catalyst preparation process comprises preparing catalyst carrier from starting material containing silicon dioxide-aluminum oxide and amorphous aluminum oxide by bringing it into contact with chelating agent and catalytically active amount of one or several metals, metal compounds, or combinations thereof in liquid carrier, ageing starting material; drying and calcinations. Method of regenerating used material involves additional stage of removing material deposited on catalyst during preceding use, while other stages are carried out the same way as in catalyst preparation process. Catalyst is suitable for treating hydrocarbon feedstock.

EFFECT: improved activity and regeneration of catalyst.

41 cl, 3 dwg, 8 tbl, 10 ex

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