Ammonia synthesis catalyst and ammonia synthesis method

FIELD: chemistry.

SUBSTANCE: invention relates to an ammonia synthesis catalyst. Said catalyst is a supported metal catalyst which is deposited on a mayenite-type compound, containing conduction electrons in concentration of 1015 cm-3 or higher and serving as a support for the ammonia synthesis catalyst. The invention also relates to a method of producing said catalyst and an ammonia synthesis method using said catalyst.

EFFECT: disclosed catalyst enables synthesis of ammonia with high efficiency in mild conditions.

7 cl, 1 dwg, 4 tbl, 11 ex

 

The technical field to which the invention relates

The present invention relates to the catalytic synthesis of ammonia, suitable for the synthesis of ammonia by the interaction of hydrogen and nitrogen, to a method for producing a catalyst for synthesis of ammonia and to a method of synthesis of ammonia using the catalyst of ammonia synthesis.

The level of technology

Mineral fertilizers (ammonium sulphate and urea), which are essential for the production of crops to sustain the continued existence of mankind, is produced from ammonia. Method of synthesis of ammonia using nitrogen and hydrogen as starting materials and using a catalyst, made mostly of iron, was opened by Mr. Haber and Bosch. This method (called "process Haber-Bosch") is used so far as the primary method of maintaining the life of mankind, even after about one century since the industrial process Haber-Bosch in 1910.

The process Haber-Bosch includes a step of direct interaction of the gas mixture of nitrogen and hydrogen for the reaction under high temperature and high pressure, from 400 to 600°C and from about 20 MPa to about 100 MPa, using double-promoted iron catalyst, which is mainly made �W Fe 3O4containing several mass percent of Al2O3and K2Oh, and the stage of allocation of ammonia formed by the reaction of N2+3H2→2NH3, by cooling the formed ammonia or absorb it with water. Even now this method is used on an industrial scale in the production process in much the same way as when it was originally implemented.

On the other hand, there is known a catalyst, using as an element of the transition metal is active in the synthesis of ammonia at a low temperature of 300°C or below, the elements of one type selected from Mo, W, Re, Fe, Co, Ru, and Os, or any of the combinations of Fe and Ru, Ru and Re and Fe and Mo mainly in the metallic state (patent literature (PTL) 1). Also the methods of synthesis of ammonia using the catalyst of any of the transition metals of group 8 or 9, for example, Fe, Ru, Os and Co (PTL 2-4). Also developed methods, in particular using ruthenium as a catalyst for the synthesis of ammonia (PTL 5-8). In addition, methods have been developed for the synthesis of ammonia using a catalyst nitrides of transition metals of group 8 or 6B and composite nitrides of Co and Mo (PTL 9 and 10).

Furthermore, the method of production of ammonia from nitrogen and water vapor by plasma contact using catalysis�'or containing the carrier material component that exhibits a catalytic activity and which is selected as at least one transition metal from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Mn, and Cu are presented in a patent application (PTL 11).

Up to the present time, to use the catalyst of ammonia synthesis, for example, Ru or Fe, with high efficiency, as carriers of the catalyst, magnesium oxide, aluminum oxide, graphite, cerium oxide, etc., and as promoters use alkali metals, compounds of alkaline metals, compounds of alkaline earth metals, etc.

When acid compound, for example aluminum oxide, is used as a carrier, it is usually necessary to add a large number of connection that serves as a promoter having a high electronegativity, with the aim of increasing electron-donor ability and obtaining a catalyst with high activity.

At the same time among the aluminosilicates of calcium containing CaO, Al2O3and SiO2as components, there is a chemical compound with mineral name "CL". Compound having the same type of crystal structure as the crystal CL bearing mineral, is called a "connection Manitowoc type". Connection Manitowoc type product has�RNA composition of 12CaO·7Al 2O3(hereinafter referred to as "C12A7"). It is reported that the C12A7 crystal has a unique crystal structure in which two of 66 oxygen ions present in the unit cell containing two molecules included in the form of "free oxygen ions" in the space inside the cell ("Caja"), which forms a skeleton structure of C12A7 (non-patent literature (NPL) 1).

After 2003, the authors found that these free oxygen ions can be replaced by a different anion. In particular, all the free oxygen ions can be replaced by electrons with keeping C12A7 in a strongly reducing atmosphere. C12A7 in which free oxygen ions are substituted by electrons, can be expressed by the chemical formula [Ca24Al28O64]4+(e-)4(hereinafter referred to as [C12A7:e-]). Matter consisting of electrons, replacing the anions, as described above, is called electricom, and electric has good electrical conductivity (NPL 2).

In addition, the authors found C12A7:e-that is a conductive connection Manitowoc type, 12SrO·7Al2O3that is the conjunction of the same type as that of C12A7, a mixed crystalline compound C12A7 and 12SrO·7Al2O3and the method of their synthesis (PTL 12). The invention relating to the compounds Manitowoc type, in which A partially replaced by Ga or In, also presented in the patent application (PTL 16). Such a connection Manitowoc type is suitable as electrode materials that require high temperature heat treatment, for example, the material of the protective film of a plasma display panel (PDP) and the material injection of charged electrons in organic electroluminescent (EL) device. The authors further found that the C12A7:e-containing conduction electrons in a concentration of 1×1019/cm3or more, and the connection of the same type as that of C12A7, can be obtained (A) by means of annealing of the single crystal C12A7 at high temperature in the vapor of an alkali metal or alkaline earth metal, (B) a method of ion implanting inactive ions into the single crystal C12A7, or (C) by way of direct solidification from the melt of C12A7 single crystal in reducing atmosphere (PTL 13).

In addition, the authors have succeeded in obtaining C12A7:e-that exhibits metallic conductivity with annealing of the single crystal C12A7 in pairs of metallic titanium (Ti), and presented the invention relating to the method of production of C12A7:e-and use it as an electron-emissive material in a patent application (PTL 14). C12A7:e-exhibiting metallic conductivity, can also be directly synthesized in powder form by mixing CaCO 3and Al2O3in the ratio 11:7, heating the mixture at 1300°C and subsequent heating of the product in the atmosphere of vapor of metallic Ca (NPL 3).

Since the electrons are included in C12A7:e-loosely held inside the cell positively charged framework structure, these electrons can be extracted to the outside, feeding the voltage or by applying chemical methods. Assuming that these electrons are extracted to the outside, can be used in a redox reaction, the authors have developed a method of producing secondary alcohols and diketonate joints by restoring ketone compounds using electron included in C12A7:e-and provided a method in a patent application (PTL 15).

List of links

Patent literature

PTL 1: Passed examination of the published patent application of Japan No. 51-47674

PTL 2: Passed examination of the published patent application of Japan No. 54-37592

PTL 3: Passed examination of the published patent application of Japan No. 59-16816

PTL 4: international publication WO96/38222

PTL 5: Not passed examination of the published patent application of Japan No. 2-258066

PTL 6: Not passed examination of the published patent application of Japan No. 9-239272

PTL 7: Not passed examination of the published patent application of Japan No. 2004-35399

PTL 8: Not passed the experimental�the Teese published patent application of Japan No. 2006-231229

PTL 9: Not passed examination of the published patent application of Japan No. 2000-264625

PTL 10: Not passed examination of the published patent application of Japan No. 2008-13435

PTL 11: Not passed examination of the published patent application of Japan No. 2001-151507

PTL 12: Domestic re-release of the international publication of PCT patent application No. 2005/000741

PTL 13: Not passed examination of the published patent application of Japan No. 2005-314196

PTL 14: Domestic re-release of the international publication of PCT patent application No. 2007/060890

PTL 15: Not passed examination of the published patent application of Japan No. 2008-214302

PTL 16: Not passed examination of the published patent application of Japan No. 2009-203126

Non-patent literature

NPL 1: H. B. Bartl and T. Scheller “N. Jahrbuch Mineral. Monatsh”, 547, (1970)

NPL 2: S. Matsuishi, Y. Toda, M. Miayakawa, K. Hayashi, T. Kamiya, M. Hirano, I. Tanaka and H. Hocono, “Science”, 301, 626-629, (2003)

NPL 3: S. Matsuishi, T. Nomura, M. Hirano, K. Kodama, S. Shamoto and H. Hosono, “Chemistry of Materials”, 21, 2589-2591, (2009)

Summary of the invention

Technical problem

Since the process Haber-Bosch reaction is reduction, it is preferable to conduct the reaction under a high pressure of about 20 MPa or higher, from the viewpoint of improving the reaction efficiency. In addition, the process Haber-Bosch requires a reaction at a high temperature, to ensure the activity of the catalyst, mainly DM�Lunn, from Fe. Accordingly, the process Haber-Bosch has drawbacks, namely that the size of the device increased synthesis and that heat losses are great. In addition, the existing method of production of ammonia is unsatisfactory in that the single-pass conversion is low, the unreacted gas shall be directed to recirculation, and the amount of energy used for recycling increases.

At the same time, we know that when the catalyst of ammonia synthesis is used. Ru, the reaction progresses at low pressure. Thus, Ru is attracting attention as a catalyst for ammonia synthesis of the second generation. However, the catalytic properties of one EN very small, and need to use a carrier or promoter compound to enhance the catalytic ability of Ru. Recently promoted Ru catalyst deposited on the carbon introduced into industrial production. Although the Ru catalyst has a high activity, it is known that, as in the interaction medium and the hydrogen in the synthesis of ammonia methane, the media loses its function, generating, thus, a serious problem in the process. For this reason, it took the development of a stable catalyst, taking into account the conditions of industrial�about the synthesis of ammonia.

The aim of the present invention is to provide a catalyst substance, which is stable and effective in the synthesis of ammonia, one of the most important chemical components of fertilizers, etc., of the substance of the catalyst exhibiting catalytic activity under mild conditions of synthesis that does not require high pressure, and also favorable from the viewpoint of saving resources. Other objectives of the present invention is to provide a method of producing a catalyst compound and method for the synthesis of ammonia by catalytic compounds.

The solution to the problem

As a result of conducting intensive studies with the intention to achieve the above objectives, the inventors found that the activity of ammonia synthesis dramatically increases due to the establishment of supported metal catalyst based on transition metal, e.g., Ru or Fe deposited on the connection Manitowoc type containing the conduction electrons, and that the catalytic synthesis of ammonia is stable in the reaction even for a long time and shows much higher performance than conventional catalysts, obtained without the use of any volatile alkali metals, alkaline earth metals and their compounds as promoter compounds.

Present the image�the notification relates to a catalyst for ammonia synthesis comprising a supported metal catalyst which is deposited on the connection Manitowoc type containing the conduction electrons in a concentration of 1015cm-3or more and serving as a carrier for catalyst for ammonia synthesis.

In connection Manitowoc type of oxide ions (O2-and O22-) included in the cell structure, are replaced by electrons, which serve as conduction electrons. C12A7 containing these conduction electrons, is expressed by the composition formula ([Ca24Al28O64]4+(O2-)2-x(e-)2x) (0<x<2). By replacing the oxide ions by electrons of the conduction electrons in a concentration of 1×1015cm-3or more can be included in the connection Manitowoc type. Thus, the connection Manitowoc kind involving the conduction electrons, can be called "conductive connection Manitowoc type". Theoretically, the maximum concentration of conduction electrons is 2.3×1021cm-3in the case of C12A7. Connection Manitowoc type containing the conduction electrons in a concentration equal to theoretical value can be obtained using the above described method.

C12A7 has catalytic properties, even when it does not include the conduction electrons. For more actively high�ti synthesis of ammonia compared with conventional catalysts, the connection Manitowoc type, nevertheless, should include the conduction electrons in a concentration of 1015cm-3or more in the catalyst of the present invention. Connection Manitowoc type containing a larger number of conduction electrons, provides a higher efficiency of ammonia synthesis. In the catalyst of the present invention, the connection Manitowoc type preferably contains conduction electrons in a concentration of 1017cm-3or more, and more preferably contains the conduction electrons in a concentration of 1018cm-3or more.

Connection Manitowoc type gives optical absorption peaks at 2.8 eV and 0.4 eV. The density of conduction electrons is determined by measuring the optical absorption coefficient. The density of conduction electrons can be simply determined using the method of diffuse reflectance when the sample is in powder form. Since the conduction electrons in the cell have spin activity, the density of conduction electrons inside the cell can also be measured using electron spin resonance (ESR). In addition, the connection Manitowoc type containing the conduction electrons, restores iodine in cases where the connection Manitowoc type dissolved in a solution containing iodine. Using this action, the density of electric�Ronov conductivity inside the cell can also be measured by redox titration.

Supported metal catalyst can be obtained by using one of the methods: impregnation, physical mixing, thermal decomposition, liquid-phase process and vapor deposition. Preferably, the supported metal catalyst is prepared using a dispersing stages of powder compounds Manitowoc type containing the conduction electrons in a concentration of 1015cm-3or more in the solvent solution of the compound of the transition metal, the evaporation of the solvent from the solution of solvent and heating the catalyst precursor obtained from the dried in a reducing atmosphere compounds of the transition metal, forming, thus, the catalytic metal by restoring the compounds of the transition metal. Ammonia can be synthesized with high efficiency by using a catalyst prepared as described above, and by reacting nitrogen and hydrogen as starting materials for the catalyst in the reaction set-up under conditions of reaction temperature from 100°C to 600°C or lower, and the pressure of the reaction from 10 kPa to 30 MPa.

Connection definition Manitowoc type

In the present invention, the term "connection Manitowoc type" itself means mayenite in the form of a mineral, rock Manitowoc type and a mixed oxide having the same crystallochemistry, that and the mayenite in the form of the mineral. Crystal connection Manitowoc type is constructed in such a way that the cage-like structure (called "cells"), having an inside diameter of about 0.4 nm, the contact surfaces of its walls and three-dimensional connected to each other. Anions, such as O2-usually included in every cell of the connection Manitowoc type, but these anions can be replaced by the conduction electrons by annealing. The concentration of conduction electrons in the connection Manitowoc type increases with increasing the annealing time.

The characteristic composition of the conductive connection Manitowoc type expressed by the formula [Ca24Al28O64]4+(O2-)2-x(e-)2x) (0<x<2). The conductive connection Manitowoc type can be obtained, for example, annealing C12A7 obtained in the sintering process in metal vapors, for example, Ca or Ti, at about 1100°C. various methods of obtaining an electrically conductive connection Manitowoc type, and any compounds obtained by these methods can in some cases be used in the present invention.

When the connection Manitowoc type annealed in pairs of metallic Ti, connection Manitowoc type containing the conduction electrons in theoretical maximum concentration of 2.3×1021cm-3 in the case of C12A7), can be obtained by annealing for about 24 hours, even when using the monocrystalline compound Manitowoc type of a thickness of 3 mm. Alternatively, the connection Manitowoc type can be obtained by solidification of the melt connection Manitowoc type having the stoichiometric composition in a reducing atmosphere. The concentration of conduction electrons connections Manitowoc type, obtained by curing in a reducing atmosphere, is less than 1021cm-3.

The conductive connection Manitowoc type can also be obtained by using ion implantation of Ar+ions at high concentration in the mix Manitowoc type. The concentration of conduction electrons resulting electroconductive connection Manitowoc type can be determined by the intensity of the optical absorption bands of 2.8 eV in the case of 12CaO·7Al2O3). When the concentration of conduction electrons electrically conductive connection Manitowoc type low concentration of conduction electrons can also be determined by the intensity of the absorption bands of electron-spin resonance.

In electrically conductive connection Manitowoc type Ca present in the formu characteristic of the composition may be partially or fully replaced, at IU�e, one or more elements of specific metals or transition metal elements selected from the group consisting of Li, Na, K, Mg, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ir, Ru, Rh and Pt. In addition, Al is present in the formu characteristic of the composition may be partially or completely replaced at least one or more elements of specific metals or transition metal elements selected from the group consisting of B, Ga, C, Si, Fe and Ge. In addition, present in the formu characteristic of the composition may be partially or completely replaced at least one or more specific elements, or elements of metals selected from the group consisting of H, F, Cl, Br, and Au.

The beneficial effects of the invention

According to the method of the present invention, ammonia can be synthesized by reacting hydrogen and nitrogen using inexpensive and non-toxic compound made of elements having a relatively high percent abundance of a number, such as calcium, aluminum and oxygen, not only with lower power consumption at a low reaction pressure of 10 kPa to 30 MPa, more preferably from 10 kPa to 20 MPa, but also with long-term stability at high efficiency, since the catalytic activity is not reduced by repeating the synthesis reaction. In addition, �the elements of transition metals, such as Fe and Co, in contrast to the expensive rare metals such as Ru, can also be used as a supported metal catalyst. Therefore, the present invention is valuable from the standpoint of efficient use of resources. In addition, due to the lack of necessity of addition of promoters such as alkali metals, compounds of alkaline metals and compounds of alkaline earth metals, in contrast to the usual media on the basis of aluminum oxide etc., the technology of production is simplified.

Brief description of figures

[Fig.1] In Fig.1 shows the dependence of ammonia formation (marked as "exit NH3/mmol g-1") from time to time (designated as "reaction time/h"), in cases where the reaction of ammonia synthesis repeatedly used Ru/C12A7:e-(the concentration of conduction electrons 1021cm-3) of example 2.

Description of embodiments of

The catalyst of the present invention, a method of producing catalyst and method of synthesis of ammonia using a catalyst (hereinafter referred to as "the method of the present invention") are described in detail below.

The method of inclusion of conduction electrons in the connection Manitowoc type

Connection Manitowoc type, used as starting material in the method of producing catalyst for�present invention, can have any form, including powder, porous material, sintered product, a thin film or a single crystal. Connection Manitowoc type may also be a connection Manitowoc type, deposited on the carrier, is made of another substance. Connection Manitowoc type containing the conduction electrons, can be directly obtained from raw materials, without temporarily receive in the form of a common connection Manitowoc type, except when used in a thin film or a single crystal. In addition, minerals Manitowoc type, slag and burned ash containing mayenite, etc., can be used as raw materials.

Powder compounds Manitowoc type containing the conduction electrons, can be obtained by heating the powder raw material compounds Manitowoc type, which has a stoichiometric composition in a reducing atmosphere. The sintered product connection Manitowoc type containing the conduction electrons, can be obtained by heating the powder raw material compounds Manitowoc type, which has a stoichiometric composition, at about 1300°C in a reducing atmosphere, thereby sintering and otorita powder.

A thin film of the compound Manitowoc type containing the conduction electrons, can be obtained using�Yu use as a target a sintered product connection Manitowoc type, forming a thin film of the compound Manitowoc type on a substrate made of, e.g., MgO or Y3Al5O12for example , the method of pulsed laser deposition (PLD), sputtering, or plasma spraying, and by repeated deposition of thin films of compounds Manitowoc type PLD method to merge with the already besieged with a thin film, by heating the latter at 500°C or higher. When repeating the PLD method connection Manitowoc type shown in the plasma state, is used as the reducing agent, so that the conduction electrons are included in the besieged thin film.

The single crystal connection Manitowoc type containing the conduction electrons, can be obtained through the formation of single crystal compounds Manitowoc type through a stage of pulling from the melt, in which the powder of the raw material compounds Manitowoc type is melted at about 1600°C (i.e. using the CZ method (Czochralski method)), sealing the formed single crystal in a vacuum glass tube, for example, with metallic Ca powder or Ti, and by heating them in a reducing atmosphere, so that the conduction electrons are included in the single crystal.

The conductive connection Manitowoc type in the form of a sintered product or monocrystalline can be processed into powder. Processing into powder may be, for example, by means of grinding using a pestle or jet mills. Although the size of the powder is not limited to particle size, when using the above method of processing the powder are particles with a diameter distributed in the range from about 100 nm to 1 mm. Connection Manitowoc type containing the conduction electrons in a concentration of 1×1015cm-3or more receive according to any one of the above solutions.

Depending on the method for obtaining the conduction electrons can disappear from the surface of the connection Manitowoc whatever type of used connection Manitowoc type, taken in the form of a powder, a porous material, sintered products, thin films and single crystal. In this case, it is desirable to heat the compound obtained Manitowoc type at temperatures below 900°C and lower than the melting temperature (1250°C) corresponding compound in vacuum, inert gas or in a reducing atmosphere, so that the conduction electrons were included up to the outer surface of the connection Manitowoc type.

Stage of deposition of the transition metal

Elements of transition metals are used as catalysts in homogeneous systems and heterogeneous systems in different reaction�the third synthesis. In particular, it is known that transition metals belonging to groups 6, 8 and 9, such as Fe, Ru, Os, Co, and Mo, are suitable as catalysts for the synthesis of ammonia by the direct interaction of hydrogen and nitrogen. In the present invention, one or more metals 6 groups, selected from Cr, Mo and W, one or more metals 7 groups selected from Mn, Tc and Re, and one or more metals of the 8th group selected from Fe, Ru and Os, and one or more metals 9 groups selected from Co, Rh and Ir, can be used as component (s) of transition metals individually or in combination. In addition, can also be used compounds of the above elements, such as Co3Mo3N, Fe3Mo3N, Ni2Mo3N and Mo2N.

In cases where powder or porous connection material Manitowoc type is used as a carrier, powder or porous connection material Manitowoc type obtained through the above stages and containing conduction electrons in a concentration of 1×1015cm-3or more, is mixed with the transition metal compound by using an impregnation method or the method of physical mixing. If you use a sintered product, a thin film, single crystal, etc. connection Manitowoc type, in addition to the impregnation method, as in the case of powder or porous material, can� to apply the method of deposition of the transition metal compound on the surface of the sintered product, thin films or single crystal by using, for example, chemical vapor deposition (CVD) or sputtering and thermal decomposition of precipitated compounds of the transition metal, thereby causing deposition of the transition metal. In cases where the connection of the transition metal compound can also be obtained, for example, using the method of deposition of any of the respective commodity metals on CL, using, e.g., CVD method, thermal decomposition of the deposited material and then nitriding it with gaseous ammonia.

Examples of transition metal compounds are, but not limited to, inorganic metal compounds and organic metal complexes, which are prone to thermal decomposition, including, for example, dodecacarbonyl [Ru3(CO)12], dichlorotris(triphenylphosphine)ruthenium(II) [RuCl2(PPh3)4], dichlorotris(triphenylphosphine)ruthenium(II) [RuCl2(PPh3)3], Tris(acetylacetonato)ruthenium(III) [Ru(acac)3], Ruthenian [Ru(C5H5)], ruthenium chloride [RuCl3], iron PENTACARBONYL [Fe(CO)5], iodide tetracarboxylate(II) [Fe(CO)4I2] chloride, iron(III) [FeCl3], ferrocene [Fe(C5H5)2], Tris(acetylacetonato)iron(III) [Fe(acac)3], dodecacarbonyl [Fe3(CO)12], CL�reed cobalt(III) [CoCl 3], Tris(acetylacetonato)cobalt(III) [Co(acac)3], acetylacetonate cobalt(II) [Co(acac)2], octacarbonyl cobalt [Co2(CO)8], cobaltocene [Co(C5H5)2], dodecacarbonyl triose [Os3(CO)12] and hexacarbonyl molybdenum [Mo(CO)6].

The method of impregnation may be performed, for example, as follows. Powdered catalyst is dispersed and stirred solution of compound of the transition metal (for example, in the hexane solution of the carbonyl complex of Ru). At the same time load the compound of the transition metal is from 0.01 to 40 wt.%, preferably from 0.02 to 30 wt.%, and more preferably from 0.05 to 20 wt%. regarding powdery media. After this, the solution is heated at a temperature of from 50 to 200°C for from 30 minutes to 5 hours in a stream of inert gas such as nitrogen, argon or helium, or under vacuum to evaporate the solvent to dryness. Then restore the catalyst precursor obtained from the dried compounds of the transition metal. Through the above stages get a supported metal catalyst in which a transition metal is deposited in the form of fine particles having a diameter from several nanometers to several hundreds of nanometers, a powder carrier.

The specific surface area of supported metal �of analizatora is from 0.1 to 100 m 2/g, and the content of transition metal is from 0.01 to 30 wt.%, preferably from 0.02 to 20 wt%. and more preferably from 0.05 to 10 wt%. regarding powdery media. Powdered carrier, which is deposited on the transition metal contains electrons at a concentration comparable to the concentration at the initial stage, even after the stage of deposition of the transition metal, and has a low work function when using as a carrier. Thus, the powdered carrier exhibits a high ability of electron donor to transition metal and largely contributes to the activation of nitrogen and hydrogen on transition metal, thus acting as a high-performance catalyst for ammonia synthesis. High performance, quite likely due to the fact that sufficient injection of electrons in the transition metal, which is closely linked to the carrier surface Electrica, occurs by dissociation of hydrogen and nitrogen. The catalyst of the present invention functions as a high-performance catalyst for ammonia synthesis, even if any of the alkali metal, alkaline earth metal and their compounds are not used as promoter compounds. However, this promoter compound can be used additionally as needed�configured.

Similar supported metal catalyst can also be obtained, instead of the above-described method, by mixing the powder compounds Manitowoc type containing the conduction electrons in a concentration of from 1×1015cm-3or more, and the powder of the compound of the transition metal in the solid phase by the method of physical mixing, and then heating the mixture under conditions similar to those described above for the reductive decomposition of the compound of the transition metal in the transition metal.

In addition, the supported metal catalyst can also be obtained in the form of molded articles using conventional molding method. In practice, a molded article can take any form, such as pellets, spheres, tablets, rings, worm, four-petal clover, dice and honeycombs. Alternatively, a supported metal catalyst can be used after application to a suitable substrate.

The synthesis of ammonia

Method of synthesis of ammonia present invention is a method using as a catalyst the above-described supported metal catalyst and the interaction of hydrogen and nitrogen on the catalyst. The usual reaction is, as in the known process Haber-Bosch direct interaction of the gas mixture of nitrogen and hydrogen during heating�AI and under pressure and in the release of ammonia formed by the reaction of N2+3H2→2NH3with the help of cooling the formed ammonia or absorb it with water. Gaseous nitrogen and hydrogen serves to bring into contact with a supported metal catalyst, placed in the reaction vessel. Unreacted gaseous nitrogen and hydrogen again returned to the reaction vessel after removal of the formed ammonia. Preferably before the supply of gaseous nitrogen and hydrogen pre-treatment for removal of oxides, etc., attached to the deposited transition metal in a regeneration process on the surface of supported metal catalyst as a reducing treatment using hydrogen gas or a gas mixture of hydrogen and nitrogen.

Connection Manitowoc type preferably adsorbs moisture from the air and decomposes in the presence of excess moisture. Therefore, it is desirable that the reaction of ammonia synthesis was carried out in an atmosphere containing as little moisture, i.e. when using gaseous nitrogen and hydrogen with a moisture content of from 100 part per million (ppm) or less, preferably 50 hours/million or less.

Ammonia is synthesized by heating the supported metal catalyst in an atmosphere of a gas mixture AZ�and hydrogen as starting materials. As a condition of the synthesis of ammonia in a molar ratio of nitrogen to hydrogen is from about 1/10 to 1/1, preferably from 1/5 to 1/1. Reaction temperature is preferably not lower than 100°C and below 600°C, more preferably in the range from about 200°C or higher to about 500°C, and even more preferably in the range from about 250°C or higher to about 500°C. lower reaction temperature is preferred to maintain equilibrium more satisfactory for the formation of ammonia. It is desirable that the reaction temperature was in the above range from the viewpoint of ensuring a sufficient rate of formation of ammonia and at the same time preserving a satisfactory equilibrium for the formation of ammonia.

The reaction pressure of the gas mixture of nitrogen and hydrogen during the synthesis reaction is not limited to a particular level, but is preferably from 10 kPa to 30 MPa. From a practical point of view, the synthesis reaction is preferably carried out under pressure, and practically more preferable range of the reaction pressure is from about 100 kPa to 30 MPa.

The reaction unit can operate in either mode: periodic, closed circulation and flow. However, from a practical point of view the reaction setup flow type is the most preferred. R�the action of ammonia synthesis is preferably carried out under the condition of high pressure and low temperature from the viewpoint of equilibrium. In addition, since the reaction is exothermic, the reaction of ammonia synthesis is preferably carried out while discharging the heat. Various devices proposed to increase the yield from the industrial point of view. For example, when using a flow-through reactor is proposed a method of obtaining a high yield of ammonia, in which several reaction vessels, filled with catalyst, are connected in series and the temperature at the inlet of each of the reaction vessels reduced by installing the intercooler at the outlet of each reaction vessel for heat sinking. Also the method of application of the reaction vessel, which includes inside several layers of catalyst, filled with an iron catalyst and a catalyst based on Ru, and precise temperature control at the outlet of each reaction layer.

In the present invention, the ammonia can be synthesized using, as in the known methods, one reaction vessel or more reaction vessels, each reaction vessel filled with the catalyst. The catalyst used for the synthesis of ammonia, may be one of the catalysts of the present invention, a combination of two or more types selected from the catalysts of the present invention, or a combination of one or more of the CA�the moat of the present invention and one or more of the known catalysts. You can also use any other suitable method, for example, combining multiple reaction vessels or the use of the reaction vessel comprising several reaction layers in a single vessel.

In cases where the present invention uses a combination of catalysts, the catalyst of the present invention is preferably used in the reaction vessel of the last stage, because it exhibits increased activity at lower temperatures. In other words, a higher yield of ammonia can be obtained by using the last reaction in so low a temperature, which is preferable from the viewpoint of equilibrium.

In the equilibrium reaction for the industrial synthesis of ammonia the concentration of ammonia in the reaction gas at the outlet of the reaction vessel is 20% or less due to restrictions on the equilibrium of the reaction. Accordingly, after cooling and extracting ammonia formed from the reaction gas unreacted starting materials are removed from the system for recycling to be reused as raw materials after the separation step, the reaction gas and of the impurities contained in the unreacted starting materials.

Hydrogen as a starting material of the method of synthesis of ammonia m�can be represented by any of hydrogen gas, which is obtained in various ways, for example, ways to use coal, oil or natural gas as feedstock and hydrogen production combined process of steam reforming, partial oxidation reforming, autothermal reformer and the reforming reaction, the method of use of biomass as raw material, the electrolytic decomposition of water and method of decomposition of water using photocatalyst.

When using natural gas as a starting material for the method of synthesis of ammonia, hydrogen and nitrogen obtained using the stage steam reforming stage and a partial oxidation reforming, each of which runs on natural gas, the stage of conversion of CO, the stage of assignment of CO2and the next stage of abstraction with CO conversion of CO to methane. Since the steam reforming reaction is endothermic, uses the heat of reaction generated in the autothermal reaction. When using air as a raw material gaseous nitrogen, the ratio H/N is approximately 1.7 to 2.5 molar ratio. Since the unreacted gas after stage steam reformer contains hydrogen gas, it is preferably fed to the stage steam reforming for reuse as gas Retz�rouletii. Developed efficient method of conducting the reaction by regulating the ratio of fresh gas to the gas recirculation. Similarly, this method can also be used in the present invention.

On the other hand, developed a method of using oxygen-enriched air as the method of obtaining the starting material with a higher ratio of H/N. This method is preferable from the viewpoint of energy savings, since the amount of gas recirculation is reduced when using a starting material with a higher ratio of H/N. furthermore, the method of separation of air by compressing and further use of oxygen for hydrogen production via autothermal process and the use of nitrogen in the reaction gas or process nitrogen is the preferred method from the viewpoint of energy saving. Any of the above methods can also be used in the present invention as a way of obtaining the source material.

The present invention will be described below in more detail with reference to examples. The activity of ammonia synthesis was evaluated by quantifying the release of NH3using gas chromatography and determining the rate of ammonia formation.

Example 1

The preparation of the compound Manitowoc type, containing�the conduction electrons

Respective powders of CaCO3and Al2O3were mixed together at a molar ratio of Ca to Al 11:7 and heated at 1300°C for 6 hours in a crucible made of aluminum oxide. The resulting powder was placed in a tube made of quartz glass and heated at 1100°C for 15 hours in a vacuum of 1×10-4PA. 3 g of the thus obtained powder was sealed in a tube of quartz glass together with 0.18 g of a powder of metallic Ca and heated at 700°C for 15 hours, thereby filling the inner space of the tube metal pairs Ca. There was obtained a powder of C12A7:e-with the concentration of conduction electrons is 2×1021cm-3(denoted as C12A7e21).

Deposition of Ru on the powdery carrier

1 g of powder C12A7e21obtained as described above was mixed with Ru3(CO)12dissolved in the hexane solvent, and the solvent evaporated to dryness. At the same time, the number of Ru3(CO)12the solvent was regulated so that the amount of Ru deposited on the powder C12A7e21accounted for 6% of the mass. regarding powder C12A7e21. The resulting powder was heated at 100°C for 4 hours under vacuum, whereby removed the remaining component of the solvent and formed the precursor of the catalyst. The catalyst precursor was further subjected to thermal bath�treatment at 400°C for 3 hours in an atmosphere of hydrogen gas (to 26.7 kPa) to restore Ru 3(CO)12. There was obtained supported metal catalyst, made of powder Electrica (EN/C12A7e21) with applied metallic Ru. Specific surface area according to the BET method of the catalyst was approximately 3 m2g-1.

The reaction of ammonia synthesis

Cooperated gaseous nitrogen (N2) and gaseous hydrogen (H2) and the formation of gaseous ammonia (NH3). The interaction was carried out by placing 0.3 g of the catalyst obtained as described above, in a U-shaped glass tube and attaching the U-shaped glass tube it is made of glass installation of a closed circulation. Made of glass, the installation of a closed circulation, to which was attached a U-shaped glass tube had an internal volume of 200 ml. Before interaction perform pre-processing on the surface of Ru/C12A7e21at 400°C for 3 hours, by the introduction of H2when to 26.7 kPa in a closed circuit circulation. After this interaction was carried out at 400°C with the introduction of N2when at 6.7 kPa and H2when to 20.0 kPa. The reaction was continued for 4 hours, 8 hours and 12 hours and measured the release of NH3depending on the time. Quantification of the product was performed by gas chromatography. The measured rate of formation of ammonia PR�are presented in table 1.

Example 2

The reaction of ammonia synthesis was performed in the same conditions as in example 1, except that used C12A7, having the stoichiometric composition and containing conduction electrons in a concentration of 1×1019cm-3(I. e. C12A7e19). The measured rate of formation of ammonia is shown in table 1.

Comparative example 1

The reaction of ammonia synthesis was performed in the same conditions as in example 1, except that used C12A7 (non-alloy) having a stoichiometric composition, but not containing conduction electrons, is electrically conductive connections Manitowoc example type 1.

Comparative example 2

The reaction of ammonia synthesis was performed in the same conditions as in example 1, except that used γ-Al2O3(specific surface area by the BET method 170 m2g-1), instead of the electrically conductive connection Manitowoc example type 1.

Comparative example 3

The reaction of ammonia synthesis was performed in the same conditions as in example 1, except that used CaO (specific surface area by the BET method 4 m2g-1), instead of the electrically conductive connection Manitowoc example type 1.

Comparative example 4

The reaction of ammonia synthesis was performed in the same conditions as in example 1, except that�about, use of activated carbon (specific surface area by the BET method 800 m2g-1instead of the conductive connection Manitowoc type of example 1. The measured rate of formation of ammonia is shown in table 1.

Table 1
CatalystSpecific surface area by BET
(m2·g-1)
The rate of formation of NH3
µmol·
g-1·h-1
µmol·
m-2·h-1
Example 16%Ru/C12A7e213500167
Example 26%Ru/C12A7e19318261
Comparative example 16%Ru/C12A7:
unalloyed
33712
Comparative example 26%Ru/γ-Al2Osub> 3170330,19
Comparative example 36%Ru/CaO4133,3
Comparative example 46%Ru/AC800490,06

As you can see from those listed in table 1 velocities of ammonia formation, deposited Ru catalysts on a carrier made of, for example, γ-Al2O3, CaO and activated carbon (AC) have almost comparable performance with Ru deposited on C12A7 (unalloyed). On the other hand, also shows that the catalytic activity is greatly increased along with the increase in the content of doped electrons, and that C12A7e21with applied EN demonstrates the performance is about 10 times higher than existing catalysts. This high level of performance is likely due to the fact that sufficient injection of electrons in the Ru metal, which is closely in contact with the carrier surface Electrica, occurs by dissociation of hydrogen and nitrogen.

Example 3

After the implementation of the synthesis reaction for ten with superfluous cha�s in the same conditions, as in example 1, the reaction system was transferred to the state of vacuum. The synthesis reaction is then carried out again at 400°C for ten hours, introducing N2when at 6.7 kPa and H2when 20,0 kPa in the reaction system. The stability of the catalyst was evaluated by repeating the above operations, more than three times. Fig.1 presents the results of a repetition of the synthesis reaction using as a catalyst Ru/C12A7e21. The curves in Fig.1 from left to right represent the results of the first, second, third, fourth and fifth fusion reactions. As can be seen from Fig.1, even after a fivefold repetition of the synthesis reaction is the decrease in catalytic activity is not manifested, and all synthesis reaction progresses under the action of the catalyst. Thus, it is proved that the catalyst of the present invention is not impaired during the synthesis reaction and remains stable even after prolonged use.

Example 4

Deposited Ru catalyst was created instead of a method of applying a Ru powder on the carrier in example 1 using the physical mixing of powdery carrier and Ru3(CO)12using a ball mill without the use of solvent and then carrying out heat treatment of the mixture in vacuum at 450°C for 2 hours. When performing the reaction of ammonia synthesis in the same manner as in PR�least 1, got a result similar to the result in example 1.

Example 5

The reaction of ammonia synthesis was performed in the same conditions as in example 1, except that used the carbonyl iron instead of Ru3(CO)12in example 1. Specific surface area according to the BET method of the catalyst, made of Fe deposited on the powder Electrica was approximately 3 m2g-1. The rate of formation of ammonia was 38 mmol g-1h-1(13 µmol m-2h-1). Thus, it was confirmed that the catalyst of example 5 to synthesize ammonia at a lower temperature and lower pressure than known catalysts using iron. Under the reaction conditions similar to that given in example 5, ammonia is not formed using known catalysts made on the basis of calcium oxide, γ-alumina, and carbon, each of which contains the applied Fe.

Example 6

Deposition of Ru on the powdery carrier

1 g of powder C12A7e21and 0,042 g Ru3(CO)12was placed in a glass tube made of glass "Pyrex" (Pyrex (registered trademark), and the glass tube was sealed after evacuation. The mixture was subjected to heat treatment in accordance with the following programme until evacuated and germetizirovany the tube was rotated in electric�tion of the furnace.

[40°C, 20 min warm-up → 40°C, 60 min exposure → 70°C, 120 min warm-up → 70°C, 60 min exposure → 120°C, 120 min warm-up → 120°C, 60 min exposure → 250°C, 150 min warm-up → 250°C, 120 min hold]

Then evacuated and sealed glass tube was broken, and electric coated with 2% by weight. EN (i.e. 2% of the mass. Ru/C12A7e21) was obtained by heating up to 300°C for 5 hours and subsequent heat treatment for 2 hours in an atmosphere of hydrogen gas (to 26.7 kPa).

The reaction of ammonia synthesis

Cooperated gaseous nitrogen (N2) and gaseous hydrogen (H2and the formation of gaseous ammonia (NH3). The interaction was carried out by placing 0.2 g of the catalyst obtained as described above, in a tube of quartz glass, and attach the tube made of quartz glass to flow to the reactor. The reaction conditions were set so that the total gas flow rate was 60 ml/min, i.e., N2:15 ml/min and H245 ml/min, the pressure was atmospheric, and the reaction temperature was 400°C. the Gas exiting the reaction vessel in the flow-type installation, barbotirovany in a 0.005 M aqueous solution of sulfuric acid, thus causing the dissolution of the obtained ammonia in solution. Educated ammonium ions quantitatively measured by the method of ion chromatog�aafia. The results of the reaction are presented in table 2.

Method of calculation of the TOF

The term "engine speed (TOF)" means the number representing the catalytic reaction, many times a single active site contributed to the reaction, on average, per unit time, and it is calculated by dividing the number of reacting molecules formed per unit time, the number of catalytically active centers. As developed here in the catalytic reaction with the active center is Ru, TOF is obtained by determining the number of Ru atoms exposed on the surface of the catalyst by CO adsorption, and dividing the number of molecules of ammonia formed per unit time, the number of Ru atoms.

Example 7

Deposition of Ru on the powdery carrier

The catalyst was synthesized under the same conditions as in example 6, except that used 0,0105 g Ru3(CO)12and received electric coated with 0.5% by weight. EN (i.e. 0.5% of the mass. Ru/C12A7e21).

The reaction of ammonia synthesis

The reaction of ammonia synthesis was performed in the same conditions as in example 6, except that used 0.5% of the mass. Ru/C12A7e21. The results of the reaction are presented in table 2.

Example 8

Deposition of Ru on the powdery carrier

The catalyst was synthesized under the same conditions as in example 6, except that the use�up 0,0021 g Ru 3(CO)12and received electric coated with 0,1% of the mass. EN (i.e. 0,1% of the mass. Ru/C12A7e21).

The reaction of ammonia synthesis

The reaction of ammonia synthesis was performed in the same conditions as in example 6, except that used 0,1% of the mass. Ru/C12A7e21. The results of the reaction are presented in table 2.

Comparative example 5

The reaction of ammonia synthesis was performed in the same conditions as in example 6, except that used C12A7 (non-alloy) having a stoichiometric composition, but not containing conduction electrons, is electrically conductive connections Manitowoc type of example 6.

Comparative example 6

The reaction of ammonia synthesis was performed in the same conditions as in examples 6-8, except that the used γ-Al2O3(specific surface area by the BET method 170 m2g-1) coated with 6 wt%. EN, instead of the electrically conductive connections Manitowoc type of examples 6-8.

Comparative example 7

The reaction of ammonia synthesis was performed in the same conditions as in examples 6-8, except that the used CaO (specific surface area by the BET method 4 m2g-1) coated with 2% by weight. EN, instead of the electrically conductive connections Manitowoc type of examples 6-8.

Comparative example 8

The reaction of ammonia synthesis was performed in the same cond�tions, as shown in examples 6-8, except that the used activated carbon (specific surface area by the BET method 310 m2g-1) coated with 9,1% of the mass. Ru and Ba (Ba/EN=6,2), instead of the electrically conductive connections Manitowoc type of examples 6-8.

Comparative example 9

The reaction of ammonia synthesis was performed in the same conditions as in examples 6-8, except that the used MgO (specific surface area by the BET method 12 m2g-1) coated with 6 wt%. Ru and Cs (Cs/EN=1), instead of the electrically conductive connections Manitowoc type of examples 6-8.

Table 2
CatalystSpecific surface BET (m2·g-1)The rate of formation
NH3
TOF (-1)
um
g-1·h-1
µmol·m-2·h-1
Example 62% of the mass. Ru/C12A7e211268426840,191
Example 7 0.5% by weight. Ru/C12A7e2119699690,258
Example 80,1 wt.% Ru/C12A7e2115825820,131
Comparative example 52% of the mass. Ru/C12A7: non-alloy1790790Of 0.056
Comparative example 66% of the mass. Ru/γ-Al2O3170520,30,0002
Comparative example 72% of the mass. Ru/CaO415839,50,005
Comparative example 89,1% of the mass. Ru-Ba/
activated charcoal
31024177,80,003
Comparative example 9 6% of the mass. Ru-Cs/MgO1231072590,008

As can be seen from the velocity of formation of ammonia, are shown in table 2, the catalytic activity is greatly enhanced by modifying the C12A7 (unalloyed) in electric (C12A7e21). In addition, compared with 9.1% of the mass. Ru-Ba/activated carbon, and 6% of the mass. Ru-Cs/MgO, which are indicated as having the highest activity among the catalysts, it is clear that the activity Electrica per unit mass is comparable in performance with these aforementioned catalysts. Comparing the activity per unit surface area as the surface area Electrica is very small, i.e., 1 m2/g Electrica shows 10 times higher performance than existing catalysts. In addition, comparing the performance (TOF) at the active site Ru, it is obvious that the performance Electrica much higher than other catalysts. This high level of performance is likely due to the fact that during the dissociation of hydrogen and nitrogen occurs sufficient injection of electrons in the metal is Ru, which is in close contact with the carrier surface Electrica.

Example 9

The reaction of ammonia synthesis

Cooperated gazoob�different nitrogen (N 2) and gaseous hydrogen (H2and the formation of gaseous ammonia (NH3). The interaction was carried out by placing 0.2 g of catalyst (0.5% by weight. Ru/C12A7e21) synthesized in example 7 in a reaction tube made of stainless steel, and the accession of the reaction tube to the flow-through reactor. The reaction conditions were set so that the total gas flow rate was 60 ml/min, i.e., N2:15 ml/min and H2:45 ml/min, the pressure was from 0.1 to 1.0 MPa, and the reaction temperature was 400°C. the Gas exiting the reaction vessel in the flow-type installation, barbotirovany in a 0.005 M aqueous solution of sulfuric acid, thus causing the dissolution of the formed ammonia in solution. Educated ammonium ions quantitatively measured by ion chromatography. The results of the reaction are presented in table 3.

Table 3 shows the catalytic activity of Electrica coated with Ru when the pressure of the reaction gas from 0.1 MPa to 1.0 MPa. The catalytic activity increases with increasing pressure, but it decreases when the pressure increases to 0.7 MPa or 1 MPa. This result is likely explained by the influence of hydrogen poisoning of the active centers of Ru. It is expected to further increase catalytic activity by changing the partial �of Alenia N 2.

Table 3
Pressure (MPa)The rate of formation of NH3
(mmol g-1h-1)
TOF (-1)
0,17320,195
0,37900,211
0,58400,224
0,77760,207
17220,193

Example 10

The application of Fe powder on the media

1 g of powder C12A7e21and 0,063 g of Fe(acac)3was placed in a glass tube made of glass "Pyrex" (Pyrex (registered trademark), and the glass tube was sealed after evacuation. The mixture was subjected to heat treatment in accordance with the following programme until vakuumirovannoi and germetizirovany the tube is rotated in an electric furnace.

[100°C, 120 min warm-up → 100°C, 60 min exposure → 200°C, 120 min warm-up → 200°C, 60 min exposure → 350°C, 150 min warm-up → 300°C, 120 min �uderzhivanie]

Then evacuated and sealed glass tube was broken, and electric coated with 1% of the mass. Fe (i.e. 1% of the mass. Fe/C12A7e21) was obtained by heating to 450°C for 5 hours and subsequent heat treatment for 2 hours, while the continued evacuation.

The reaction of ammonia synthesis

The reaction of ammonia synthesis was performed in the same conditions as in example 6, except that used 0,1% of the mass. Fe/C12A7e21. The measured rate of ammonia formation are given in table 4.

Example 11

Deposition of Co on the powdery carrier

1 g of powder C12A7e21and 0,029 g Co2(CO)8was placed in a glass tube made of glass "Pyrex" (Pyrex (registered trademark), and the glass tube was sealed after evacuation. The mixture was subjected to heat treatment in accordance with the following programme until vakuumirovannoi and germetizirovany the tube is rotated in an electric furnace.

[100°C, 120 min warm-up → 100°C, 60 min exposure → 200°C, 120 min warm-up → 200°C, 60 min exposure → 350°C, 150 min warm-up → 300°C, 120 min hold]

Then evacuated and sealed glass tube was broken, and electric coated with 1% of the mass. Co (i.e. 1% of the mass. Co/C12A7e21) was obtained by heating to 450°C for 5 hours and subsequent heat treatment in �Directors for 2 hours, while the continued evacuation.

The reaction of ammonia synthesis

The reaction of ammonia synthesis was performed in the same conditions as in example 6, except that used 1% of the mass. Co/C12A7e21. The measured rate of ammonia formation are given in table 4.

Comparative example 10

The reaction of ammonia synthesis was carried out by synthesizing deposited Fe catalyst under the same conditions as in example 10, except that used C12A7 (non-alloy) having a stoichiometric composition, but not containing conduction electrons, is electrically conductive connections Manitowoc type of example 10.

Comparative example 11

The reaction of ammonia synthesis was carried out by synthesizing cobalt catalyst deposited in the same conditions as in example 11, except that used C12A7 (non-alloy) having a stoichiometric composition, but not containing conduction electrons, is electrically conductive connections Manitowoc type of example 11.

Table 4 shows the corresponding values of catalytic activity of electrichow coated with Fe and Co as metal, unlike EN. As can be seen from table 4, the catalysts obtained by deposition of Fe and Co on C12A7e21doped with electrons, exhibit catalytic activity in 10 or more times higher than those of catalysts, p�obtained by applying Fe and Co on C12A7 (unalloyed), without doping with electrons. Thus, this confirms that the injection of electrons in Fe and Co from electrichow is also effective.

Table 4
CatalystSpecific surface area by BET
(m2·g-1)
The rate of formation of NH3um
g-1·h-1
Example 101% of the mass. Fe/C12A7e211195
Example 111% of the mass. Co/C12A7e211430
Comparative example 101% of the mass. Fe/C12A7: non-alloy13
Comparative example 111% of the mass. Co/C12A7: non-alloy140

Industrial applicability

While high blood pressure, about 20 MPa or above, in the method of synthesis (the process Haber-Bosch), which is very often used in the production of ammonia currently in�time, and which uses double-promoted iron catalyst, mainly consisting of Fe3O4and several mass percent of Al2O3and K2O, in the method of the present invention, the synthesis reaction may be conducted at relatively low pressures, without requiring high pressure. Thus, it can be argued that the method of the present invention is preferable from the viewpoint of simplifying the production technology and energy savings. In addition, in the method of the present invention can be produced ammonia at a lower price and with much greater efficiency than methods using known Ru catalysts.

1. The catalytic synthesis of ammonia, comprising a supported metal catalyst which is deposited on the connection Manitowoc type containing the conduction electrons in a concentration of 1015cm-3or more and serving as a carrier for catalyst for ammonia synthesis.

2. The catalyst according to claim 1, wherein the connection Manitowoc type is 12CaO·7Al2O3.

3. The catalyst according to claim 1, wherein the metal catalyst is at least metal elements selected from metals belonging to groups 6, 7, 8 and 9.

4. The catalyst according to claim 1, wherein the connection Manitowoc type takes one of the forms of powder, then�grained material, sintered products, thin films or single crystal.

5. The method for producing the catalyst according to any one of claims.1-4, comprising the step of applying metallic catalyst powder compound Manitowoc type containing the conduction electrons in a concentration of 1015cm-3or more, using one of the methods: impregnation, physical mixing, thermal decomposition, liquid-phase process and vapor deposition.

6. A method of producing a catalyst, in which the impregnation method according to claim 5 comprises the steps of dispersing the powder compounds Manitowoc type containing the conduction electrons in a concentration of 1015cm-3or more in the solvent solution of the compound of the transition metal, the evaporation of the solvent from the solution of the solvent and formation of the catalyst precursor obtained from the dried compound of a transition metal, and heating the transition metal compound in a reducing atmosphere, and the formation of the metal catalyst by recovering the compounds of the transition metal.

7. Method of synthesis of ammonia using a catalyst according to any one of claims.1-4, including the stage of interaction of nitrogen and hydrogen as starting materials for the catalyst in the reaction set-up under conditions of reaction temperature from 100°C to 600°C and pressure of the reaction from 10 to�and up to 30 MPa.



 

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EFFECT: invention enables to achieve high degree of extraction of nitrogen from blowout gas with minimum compressor power and low power consumption, and also reduces content of inert impurities in the synthesis loop.

14 cl, 8 dwg

FIELD: chemistry.

SUBSTANCE: invention can be used in the chemical industry. A method of the combined methanol and ammonia production from an initial raw material is realised by means of the following stages. First, synthesis-gas of the methanol production, which contains hydrogen, carbon oxides and nitrogen, is obtained by steam reforming of an initial hydrocarbon raw material at the first stage of reforming and then at the second stage of reforming with air blast. After that, carried out are: catalytic conversion of the synthesis-gas carbon and hydrogen oxides at a single-pass stage of methanol synthesis and the discharge of the methanol-containing output product, and an effluent gas flow, containing nitrogen, hydrogen and non-converted carbon oxides. The non-converted carbon oxides of the gas flow from the preceding stage are removed by hydrogenation to methane at the stage of the catalytic methanation with the formation of synthesis-gas, which has a molar ratio H2:N2, equal 3:1. Ammonia is synthesised by the catalytic conversion of nitrogen and hydrogen, with the discharge of the ammonia-containing product and effluent gas flow, containing hydrogen, nitrogen and methane.

EFFECT: claimed invention provides the creation of a simple and cheap method of the combined production of methanol and ammonia.

7 cl, 1 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention can be applied in chemical industry. Method of simultaneous obtaining hydrogen flow A, suitable for obtaining product A; enriched with hydrogen flow of synthesis-gas B, suitable for obtaining product B, depleted of hydrogen flow of synthesis-gas C, suitable for obtaining product C; and optionally, flow of carbon monoxide D, suitable for obtaining product D, from single flow of synthesis-gas X, characterised by the fact that single flow of synthesis-gas has optimised for production of product B molar ratio of synthesis-gas, determined as ratio H2/CO. Single flow of synthesis-gas X is divided into flow of synthesis-gas X1, flow of synthesis-gas X2, flow of synthesis-gas X3 and, optionally flow of synthesis-gas X4. Flow of synthesis-gas X1 is subjected to stage of realising reaction of water gas conversion aimed at conversion of CO, present in flow of synthesis-gas X1, and water in CO2 and H2. After that, CO2 and H2 are separated and discharged. Part of obtained H2 is applied as flow of hydrogen A. The other part of H2 is connected with flow of synthesis-gas X2, which after that is applied as hydrogen-enriched flow of synthesis-gas B. Flow of synthesis-gas X3 is applied as depleted of hydrogen flow of synthesis-gas C. Optionally flow of synthesis-gas X4 is processed in order to remove carbon dioxide and hydrogen from it. Obtained flow of carbon monoxide is applied as source of carbon monoxide of flow D.

EFFECT: invention makes it possible to reduce total emissions of carbon dioxide.

20 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: ammonia is produced from synthesis-gas, obtained as a result of reforming hydrocarbon raw material. Partially reformed gas, after stage of primary reforming, passes through stage of heat-exchange reforming and stage of secondary reforming. Partially reformed gas at the stage of heat-exchange reforming is reformed by indirect heat-exchange with synthesis-gas, removed from stage of secondary reforming. All steam, produced in steam recovery boilers of reforming and at enterprise sector of ammonia production, is heated in one or more superheaters, located behind ammonia converter of enterprise sector of ammonia production.

EFFECT: invention makes it possible to improve thermal integration of ammonia obtaining process, reduce predisposition to metal dusting, nitration and stress corrosion in steam recovery boilers and superheaters of enterprise.

9 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention deals with method and device for ammonia synthesis from synthesis-gas, which contains nitrogen and hydrogen. Device with, at least, one reactor (1), includes first non-cooled unit of catalyst layers (2), at least, one heat exchanging device (3), at least, two cooled units of catalyst layers (3, 41, 42), and each of units (4, 41, 42) is provided with aggregate of cooling pipes (5), and circulation line (6), at least, with one supplying device (61) and, at least, one discharge device (62). Line (6), starting from supplying device (61), passes successively down on flow of aggregate of cooling pipes (5), first non-cooled unit (2), heat exchanging device (3) and, at least, two cooled units (4, 41, 42) up to discharge device (62). Aggregate of cooling pipes (5) from each of cooled units (4, 41, 42) on discharge side of cooling pipes in each case are connected with assembled discharge device (10). Line (6) has, at least, in each case one bypass line (7) for each cooled unit (4, 41, 42), which in each case is placed between supplying device (61) and assembled discharge device (10) of aggregate of cooling pipes (5) from each cooled unit (4, 41, 42). Invention also represents synthesis of ammonia from synthesis-gas with application of claimed device.

EFFECT: method makes it possible to effectively apply possibilities of catalyst with obtaining high discharge concentration of ammonia.

19 cl, 7 dwg, 4 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical industry. The method of producing ammonia involves compressing steam, hydrocarbon material and air. Before the air compression step, the air is cooled, while ensuring stoichiometric ratio of nitrogen and hydrogen in the process. The material is cleaned from sulphur compounds. Steam and steam-air conversion of methane and carbon oxide conversion steps then follow. The obtained nitrogen-hydrogen mixture is cleaned from oxygen-containing compounds, compressed and fed for ammonia synthesis in a closed cycle from which the ammonia product is separated in liquid form.

EFFECT: invention increases efficiency of the process and increases output of the end product.

2 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry. The method of producing synthesis gas for ammonia synthesis involves feeding a gas stream containing hydrocarbons and a gas stream containing steam into a primary conversion apparatus which is equipped with a plurality of externally heated catalyst tubes, reaction of said hydrocarbons with steam in the catalyst tubes of the primary conversion apparatus at operating pressure therein of at least 45 bar to obtain a product gas, feeding the product gas and a stream of oxidative gas into a secondary conversion apparatus, reaction of the product gas with the oxidative gas and subsequent secondary conversion while providing conversion of all hydrocarbons contained in the product gas coming from the primary conversion apparatus to obtain converted gas which contains hydrogen, carbon oxides and unreacted steam, removing carbon oxides from the converted gas and obtaining synthesis gas which is suitable for synthesis of ammonia. The oxidative gas used is oxygen-rich air with molar ratio N2/O2 which enables to obtain converted gas with nitrogen content which corresponds to content which is required for stoichiometric molar ratio H2/N2 for ammonia synthesis.

EFFECT: method enables to achieve high production capacity of synthesis gas and lower capital costs and power consumption.

5 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: ammonia converter can include first shell (108), with located in it two or more separate catalyst layers (134, 136, 138, 140), second shell (106), located around first shell. First heat exchanger (168) is located outside first shell (108) and is connected with it by flowing medium (166) via flow channel (124), located inside first shell (108). Second heat exchanger (104) is located outside second shell (106) and is connected with it by flowing medium (116).

EFFECT: invention makes it possible to increase efficiency of ammonia obtaining.

20 cl, 3 dwg

FIELD: chemistry.

SUBSTANCE: coal undergoes gasification via partial oxidation in a gasification furnace 2 consisting of a hearth 2a and a gasification chamber 2b. In a desulphurisation apparatus 3, having a wet cleaning 3a and a dry cleaning section 3b, hydrogen sulphide is removed from gas generated in the gasification furnace 2. In a shift reaction reactor 4, carbon oxide contained in the gas coming out of the desulphurisation apparatus 3 is converted to carbon dioxide. A carbon dioxide scrubber 5 serves to remove carbon dioxide contained in the gas coming out of the shift reaction reactor 4. In a denitration apparatus 6, molar ratio of nitrogen to hydrogen in the gas coming out of the carbon dioxide scrubber 5 is brought to about 1:3 by removing nitrogen. Ammonia is obtained as a result of a reaction in generator 7 between nitrogen and hydrogen contained in the gas coming out of the denitration apparatus 6.

EFFECT: invention enables continuous operation of a gasification furnace for a long period of time.

2 cl, 5 dwg

FIELD: blasting.

SUBSTANCE: device to produce porous granulated ammonium nitrate comprises a drum, arranged as capable of installation as inclined relative to the horizontal line and as capable of rotation around its central axis, a feeder-batcher, a tray for supply of granulated ammonium nitrate into a loading neck of a drum and a receiving hopper. The drum is made with two internal longitudinal through cylindrical working cavities, is equipped with heat insulation along the side external surface and is arranged in a heat-protective jacket at the hollow shaft arranged as capable of supplying liquid coolant to walls of working cavities in counterflow relative to supply of granulated ammonium nitrate. The method for production of porous granulated ammonium nitrate consists in the fact that thermal treatment of granulated ammonium nitrate is carried out by means of its heating in a rotary drum to the temperature of 32.3 - 50°C, soaking at this temperature in a rotary drum for 0.5 - 5 minutes and soaking in a receiving hopper at the temperature of environment for 0.5 - 10 minutes.

EFFECT: invention provides for high efficiency, safety and ecological compatibility of a technological process.

8 cl, 7 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of preparing applied catalysts by a method of the pulse surface thermal synthesis of an active component from precursors, representing oxidants and reducing agents interacting at an increased temperature, which are either in different compounds or in one, applied on a carrier from their solutions, melts or suspensions with the following drying. The claimed method includes moving the carrier with the precursors of the active component applied on it through a high-temperature zone with the temperature not lower than 200°C at the speed, ensuring the growth of its temperature by not less than 10°C per minute.

EFFECT: method makes it possible to obtain catalysts with high activity, and ensures easy and reliable adjustability of the production process.

4 cl, 1 tbl, 6 ex

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