Catalyst for recombination of hydrogen and oxygen and method of making said catalyst
SUBSTANCE: invention can be used for hydrogen recombination in reactor sections of nuclear power stations and other facilities. Description is given of a catalyst for recombination of hydrogen and oxygen, containing a solid porous carrier with hydrophobisated catalytic coating of a platinoid metal. This catalyst is distinguished by that, the carrier is made from a valve metal, obtained using powder metallurgical technique, with specific surface are of 0.05-1.50 m2/g; the catalyst carrier is made from porous plates of titanium or o tantalum, or niobium, or zirconium of thickness 0.3-2.0 mm. Described also, is a method of making the said catalyst, involving saturation of the carrier with a solution of platinoid compound, reduction of the said compound to a metal, as well as hydrophobisation of the catalytic coating by moistening it with a suspension of fluorine-containing polymer with an organic stabiliser and subsequent calcination. This method is distinguished by that, the carrier is kept in the suspension for 5-30 s. The carrier is held in a single position and all stages for preparation of hydrophobisated catalytic coating are carried out in that position. Translational oscillations at frequency 1-2 Hz are imparted when saturating the carrier.
EFFECT: provision for reliable functioning of the catalyst for recombination of hydrogen and oxygen in conditions of prolonged contact with wet medium, as well as cutting on preparation time.
3 cl, 1 tbl, 1 ex, 2 dwg
The invention relates to the manufacture of catalysts and can be used for recombination of hydrogen in the reactor plants nuclear power plants (NPPs) and other business enterprises, where the leak or accident possibly explosive concentration of hydrogen in a confined space. Working (actually catalytic) component of such catalysts is usually a metal from the group of platinum, often dispersed platinum or palladium, which are applied to the media (based on catalyst) of different shapes, made from stainless steel, a highly porous inert oxides, and other chemically resistant materials. Such catalysts can operate in passive mode, i.e. without additional heating, linking the hydrogen reaction
Heat of reaction (1) leads to the heating of the catalyst, so that the resulting water evaporates from the surface, taking some of the heat:
Patinirovanie media is carried out by deposition of the metal-catalyst or applying to a solution of compounds of platinum, often of a solution of hexachloroplatinic acid (PVC), followed by a chemical recovery (often hydrogen) cation to metal molds, as well as thermal decomposition PVC and other salts of platinum.
Forming the I reactions (1) and (2) water, as well as the moisture of the surrounding gas space may block the surface of the catalyst. In the mode of the Fukushima nuclear disaster is not excluded and periodic flooding of the catalyst. Condensation on the catalyst surface slows casamassimo and can lead to complete passivation of recombination. To prevent "wetting" of the catalyst, it is subjected to a hydrophobization, resulting in its surface becomes water-repellent properties. As the water-repellent agent usually use some non-polar chemical compounds and polymers, in particular powdered Teflon-4.
Known catalyst for the recombination of hydrogen and oxygen, containing a porous solid media gidrofobizirovannym catalytic coating of the metal of the platinum group  is similar. In this catalyst carrier is made in the form of cylindrical rods of crystal modification of γ-Al2About3with a specific surface area of about 100 m2/, the Catalyst can operate in conditions of periodic contact with water, but because of the high porosity only briefly (about 1 minute). Possessing hydrophilic properties of γ-Al2About3absorbs up to 30 wt.% water, which significantly slows down the self-heating of the catalyst and reduces its starting characteristics, especially when the tempo is the temperature, close to the room.
Known catalyst for the recombination of hydrogen and oxygen, containing a porous solid media gidrofobizirovannym catalytic coating of the metal of the platinum group  is a prototype. In this catalyst carrier is made in the form of plates made of stainless steel substrate with a coating of highly porous aluminum oxide and / or other chemically and thermally stable oxides. However, it will be very difficult to achieve a strong adhesion on steel substrate and to prevent its detachment (shedding) in normal operating conditions. The fact that the catalyst must operate in a wide temperature range from room temperature up to about 600°C, and the two contacting phases are the coefficients of thermal expansion that differ by many times. In addition, the production of such a catalyst requires a fairly complex multi-stage technologies with the use of expensive equipment.
One of the expected results of the invention is to ensure reliable operation of the catalyst for the recombination of hydrogen and oxygen under conditions of prolonged contact with a wet environment.
This result is achieved in that in the catalyst for the recombination of hydrogen and oxygen, containing a porous solid media gidrofobizirovannym catalytic coating and the metal of the platinum group, according to the invention the carrier is made of obtained by powder metallurgy valve metal with a specific surface area of 0.05-1.50 m2/, While the carrier can be made of porous plates titanium, or tantalum, or niobium, or zirconium thickness of 0.3-2.0 mm
A known method of manufacturing a catalyst containing a porous solid media gidrofobizirovannym catalytic coating of the metal of the platinum group, comprising a carrier impregnated with a solution of compounds platinoid, the recovery of the compounds to metal and hydrophobic catalytic coating by wetting his suspension fluorine-containing polymer with an organic stabilizer and subsequent annealing  the prototype.
Another expected result of the invention is the reduction of cooking time and reduce the cost of the catalyst by reducing the number of stages of the technological process while maintaining the hydrophobic properties of the catalytic coating.
This is ensured by the fact that in the implementation of the method of manufacturing a catalyst containing a porous solid media gidrofobizirovannym catalytic coating of the metal of the platinum group, comprising a carrier impregnated with a solution of compounds platinoid, restore the specified connection to the metal, and g is totalization catalytic coating by wetting his suspension fluorine-containing polymer with an organic stabilizer and subsequent calcination, according to the invention the time-keeping media in suspension is 5-30 s, the carrier is fixed in one position, and in this position perform all stages of preparation gidrofobizirovannogo catalytic coating, during the impregnation of the carrier reported sustained oscillations with a frequency of 1-2 Hz.
Porous metal produced by the method of powder metallurgy, preferably titanium, does not require additional coating of highly porous substrate and has a relatively low specific surface. The number of stages of preparation of a new catalyst is limited by the stage of impregnation of porous titanium in solution PVC (no more than 1 hour), short-term immersion in a suspension of water-repellent (no more than 20 seconds) and annealing in a furnace less than 1 hour. General technological cycle of preparation of a new catalyst requires no more than two hours.
Figure 1 shows schematically the sequence of manufacture of the catalyst according to the invention; figure 2 - setup for testing of the catalyst of this type.
To simplify technology and reducing losses PVC original carrier - plate 1 made of porous titanium clip (figure 1) in a hanging position using titanium wires 2 tripod 3. In this fixed position, the plates pass all three stages (a, b, C) preparation of ka is alistor. Tripod with 3 plates 1 only transferred from one technological cycle in the other, and immersion are only processed plate 1.
In the first stage And the plate 1 made of porous titanium impregnated with a solution PVC in the tub 4, indicated by the lines 5, 6 are not shown in the drawing by thermostat. For intensification of mass transfer in the solution to the arm 3 by means of a vibrator (shaker) 7 report of the horizontal translational oscillations with a frequency of 1-2 Hz. In the second stage In plate 1 5-30 seconds is placed into the tub 8, is filled with a suspension of fluorine-containing polymer with an organic stabilizer. And finally, at the stage With plate 1 calcined in a furnace 9, where both are two main processes: patinirovanie media and the formation of a protective film of a porous water-repellent. During annealing the decomposition of the stabilizer suspension to simple monomers. These products, with strong reducing properties, restore PVC to metallic platinum. As a result, in the pores of the support (porous titanium) is formed of a catalytically active layer of the dispersed platinum mixed with the dispersed phase gidrofobizirovannogo coverage. For the preparation of catalytic plates with a total area of 90 DM2this installation requires no more than two hours.
Catalic the ical phase dispersed platinum firmly adsorbed in the surface of the porous layer of the device - porous titanium, without application of the special substrate-sorbent. Low specific surface of porous titanium (0.05 to 1.50 m2/g) sufficient for sorption of disperse platinum, on the one hand, and practically does not create conditions for the sorption of large quantities of water: maximum water sorption in porous titanium is less than 0.3 wt%. The fact that the metal catalyst (platinum) sorbed directly in the media, good adhesion is achieved platinum.
Check the quality of the prepared catalyst is performed on the test machine (figure 2) in a special chamber 10. The camera is equipped with a thermostat 11, a nozzle 12 for dosed injection of hydrogen from the electrolytic cell (not shown), the analyzer 13 of the hydrogen concentration, the device 14 for dehumidification or humidification of the gas space, the fixing device 15 of the specimen (plate 1 area of 200 cm2) catalyst, a temperature measurement system in the chamber and the samples (not shown) by means of thermocouples 16, and a computer processing system kinetic and temperature data (not shown).
The quality of the catalyst is evaluated by three parameters: activation time (τactin short, specific recombination velocity of hydrogen (i) in milliliters oxidizable hydrogen for 1 minute, referred to the unit width is s the lower part of the sample (ml/min cm), and the time of reactivation (time of return to active status) of the sample in minutes after 10-30 minutes of submersion in water (τreact). For this purpose the samples (plate 1) of the catalyst is alternately placed in the camera 10 (hung under the lid)filled with air with the hydrogen content of about 2% vol. at 25°C. the sample Temperature is controlled using a chromel-alumaloy thermocouple 16.
Example. Plate 1 made of porous titanium with a specific surface area of from 0.05 to 1.50 m2/g of various sizes with a thickness of 0.9 mm, hanging on titanium wires 2 to the tripod 3 (figure 1), was immersed in a solution with PVC at a temperature of 75°C. For intensification of mass transfer to the arm 3 by means of a shaker 7 reported progressive horizontal vibrations with a frequency of 1 to 2 Hz. 10 minutes after the end of the sorption process PVC plate was removed from the bath and for different samples of 5-30 seconds, immersed in a bath of 8 with an aqueous suspension of PTFE powder brand f-4D and then for 30 minutes was placed for calcination in the furnace 9 at a temperature of 310°C. the Cooled after annealing the catalyst samples were tested in the chamber 10 (figure 2). The contact time of the sample with water during the tests was 13 minutes. The test results of samples of different shapes and areas listed in the following table.
|Stationary hydrogen concentration, % vol.||The activation time (τactin minutes||Specific activity (i) in ml/min cm||The period of reactivation (τreactin minutes|
|10,0 x 10,0||2,04||<1||43,4||<1|
As can be seen from the table, both parameters are: τactand τreactdo not exceed 1 minute, which is considerably less than the time of reactivation for samples of the catalyst according to [1, 2].
Sources of information
1. SU # 1747146, 5 01J 37/02, 1990.
2. A two-pronged approach to hydrogen reduction. / Reinhard Heck and Axel Hill // Nuclear Engineering International. July 1992, p.21-28.
1. The catalyst for the recombination of hydrogen and oxygen, containing a porous solid media gidrofobizirovannym catalytic coating of the metal of the platinum group, characterized in that the carrier is made of obtained by powder metallurgy valve metal with a specific surface area of 0.05-1.50 m2/year
2. The catalyst according to claim 1, characterized in that the carrier made of a porous plates of titanium or tantalum, or niobium, or zirconium thickness of 0.3-2.0 mm
3. A method of manufacturing a catalyst corresponding to one of claim 1 or 2, comprising a carrier impregnated with a solution of compounds platinoid, the recovery of the compounds to metal and hydrophobic catalytic coating by wetting his suspension fluorine-containing polymer is an organic stabilizer and subsequent calcination, characterized in that the time-keeping media in suspension is 5-30 s, the carrier is fixed in one position and in this position perform all stages of preparation gidrofobizirovannogo catalytic coating and during the impregnation of the carrier reported sustained oscillations with a frequency of 1-2 Hz.
SUBSTANCE: described is passive catalytic recombiner of hydrogen, which contains body with inlet and outlet sections and catalysts which are placed in lower part of body, each catalyst is obtained by hydrothermal synthesis by precipitation of aluminium hydroxide in suspension of zirconium dioxide nanoparticles.
EFFECT: stability and high rate of hydrogen oxidation in conditions of natural convection.
3 cl, 9 dwg
FIELD: atomic power stations accident prevention equipment.
SUBSTANCE: the invention is pertaining to the field of atomic power stations accident prevention equipment. The invention presents a working member of a catalytic burner of hydrogen made in the form of a long-sized object made out of a material ensuring hydrogen flameless catalytic burning. The crosscut size of the long-sized object "d" is determined by the following formula: where "n" is the factor of safety demonstrating in how many times the minimal temperature in Kelvins of ignition of the air-hydrogen mixture is increased at utilization of the catalytic burner working member having the form of the long-sized object with the crosscut size "d", expressed in micrometers. Advantages of the invention consist in an increased safety of atomic power stations at utilization of the catalytic burners of hydrogen in rooms.
EFFECT: the invention ensures an increased safety of atomic power stations at utilization of the catalytic burners of hydrogen in rooms.
2 cl, 2 dwg
FIELD: nuclear power engineering, transport, chemical mechanical engineering, and other industries.
SUBSTANCE: proposed method for recombining hydrogen and oxygen in gas medium meant to ensure hydrogen safety includes bringing of gas mixture in contact with heated catalyst body disposed along heat-conducting channel to ensure heat transfer between them. Temperature of heat-conducting channel hot end at point of its contact with catalyst body is maintained between 150 and 350 °C and temperature of its cold end at point of its contact with catalyst body is maintained below that of hot end. Gas mixture is passed through catalyst body from cold end of heat-conducting channel to its hot end. Hydrogen-and-oxygen recombiner has case with inlet and outlet sections, as well as heat-conducting channel disposed in-between and catalyst body placed on the path of gas mixture flow along heat-conducting channel. The latter is equipped on conducting end with cooling device and on outlet end, with heater. Hydrogen concentration working range is extended to 0.5 - 25% of gas mixture.
EFFECT: enlarged hydrogen concentration range, enhanced operating reliability under different operating conditions.
5 cl, 2 dwg
FIELD: nuclear power engineering.
SUBSTANCE: the proposed facility for hydrogen burning at nuclear power plants has the following units: 1) catalytic reactor for hydrogen burning; the inlet pipe of the reactor is connected with the system of pipe-lines, supplying the steam-gas medium through a mixer; 2) water-gas ejector is connected through its ejected line with outlet pipe of the catalytic reactor for hydrogen burning; 3) sprinkler system with pumps, to which the ejecting line is connected; 4) pressure line of the ejector is connected with sprinklers through a throttling device.
EFFECT: increased efficiency of steam-air medium cleaning from radionuclides.
7 cl, 4 dwg
SUBSTANCE: there is disclosed selective oxidation catalyst of gas hydrogen sulphide to element sulphur on carbon carrier containing natural ferric oxide. Herewith catalyst is additionally introduced with ferric oxide in amount 0.5-2.0 wt % and magnesium oxide in amount 0.1-0.5 wt % on metal basis. Substrate is high-ash microcellular carbon carrier made of low-caking fossil coal by crushing, water granulation, drying, carbonisation in inert medium, and gas-vapour activation. Besides, there are described method of catalyst production and method of gas desulphurisation.
EFFECT: production of new catalyst ensuring comprehensive adsorption catalytic removal of hydrogen sulphide in gas, improved engineering-and-economical performance ensured with temperature reduction, higher sulphur content and catalyst service life.
5 cl, 2 tbl, 31 ex
SUBSTANCE: proposed plasma chemical method of producing chromia-alumina catalyst for dehydrogenation of hydrocarbons involves thermal processing of initial reagents, taken in form of aluminium and chrome carbonyl powder in a stream of an air low-temperature plasma. The reagents are put into the stream of the air plasma and reactor separately, in form of an aerosol with argon carrier gas in quantity, sufficient for obtaining a catalyst, containing 15-20 wt % chrome oxide and 80-85 wt % aluminium oxide, which is cooled to temperature not above 40°C in form of a pulverised stream, and extracted from the reactor. The catalyst powder undergoes oxidative processing by at least one chemical reagent, chosen from a group comprising nitric acid, ammonium nitrate, ammonium dichromate, taken in form of an aqueous concentrated solution. Excess reagent is evaporated. The processed catalyst is dried and baked in air at temperature not higher than 550°C for not more than two hours. The catalyst is processed by the given reagents at 80-100°C temperature for not more than 2 hours. Processing of the catalyst in nitric acid is carried out in an autoclave at 175°C temperature for 20 minutes.
EFFECT: increased output of the method, output of target product, its dispersiveness, retention of catalytic activity.
3 cl, 1 dwg
SUBSTANCE: invention refers to oil fraction hydroprocessing catalyst. Oil fraction hydroprocessing catalyst contains insertion metal hydride based on alloy including metal of VIII group and lanthanide with catalyst having response surface and monoatomic hydrogen thereon. Oil fraction hydroprocessing catalyst contains insertion metal hydride based on alloy including metal of VIII group and metal of II group with catalyst having response surface and monatomic hydrogen thereon. Oil fraction hydroprocessing catalyst contains: radio-frequency or microwave carrier/absorber; and catalytic active phase including insertion metal hydride. Catalytic active phase thereof retains and produces monatomic hydrogen form. Oil fraction hydroprocessing catalyst contains: metal hydride with response surface; radio-frequency or microwave carrier/absorber; monatomic hydrogen on response surface; and at least one hydroprocessing component, cracking component and their combinations. Besides oil fraction hydroprocessing catalyst includes catalyst combination under p.2, where insertion metal hydride is produced by reaction of hydrogen and metal alloy A2T, where general formula A2T represents: A2-xMxT1-yBy, where x=0.0-0.5; y=0.0-0.5; A=Mg; T = at least either Ni or Cu; M=La; B = at least either Fe or Co with catalyst under p. 1 in with insertion metal hydride is produced by reaction of hydrogen and metal alloy chosen from group including AT5 and A2T14B and their combinations, where general formula for AT5 represents A1-xMxT5-y-zByCz, where x=0.0-1.0; y=0.0-2.5; z=0.0-0.5; A=Mm (misch metal); T=Ni; M = at least either La, Pr, Nd or Ce; B=Co; C = at least either Mn, Al or Cr; and where general formula for catalyst A2T14B represents A2-xMxT14-yCyDzB, where x=0.0-2.0; y=0.0-14; z=0.0-3.0; A=Nd; T=Fe; M = at least either La, Pr or Ce; B=boron; C=Co; D = at least either Cr, Ni or Mn. Besides oil fraction hydroprocessing catalyst includes catalyst combination under p. 2, where metal hydride contains Mg(2.05) Ni(0.95) Cu(0.07) with catalyst under p.1 with metal hydride containing at least either Mm(1.1)Ni(4.22)CO(0.42)Al(0.15)Mn(0.15) and Nd(2.05)Dy(0.25)Fe(1.3)B(1.05), and their combinations.
EFFECT: production of new organic compound processing catalyst.
25 cl, 7 ex, 10 tbl, 13 dwg
SUBSTANCE: nickel-copper oxide catalysts on metal carrier can be used in conversion of CO into CO2 in high-temperature processes of technological and exhaust gas purification, in particular, in energy and automobile industry. Catalysts on carrier, made from aluminium or its alloy are obtained by plasma-electrochemical method by means of carrier processing in alkali electrolyte, containing nickel acetate and copper acetate and additionally including trisodium phosphate, sodium tetraborate and tungstate with following ratio of components, g/l: nickel acetate Ni(CH3COO)2·4H2O-5-20; copper acetate Cu(CH3COO)2·H2O-1.3-5.0; trisodium phosphate Na3PO4·12H2O-20-30; sodium tetraborate Na2B4O7·10H2O-10-20; sodium tungstate Na2WO4·2H2O-1-3. Plasma-electrochemical processing is carried out in galvano-static mode by pulse current, alternating or alternating unidirectional, with impulse duration 0.0033-0.04 sec, voltage 240-400 V, efficient current density 5-20 A/dm2 and electricity amount consumption 1500-6000 C/dm2 of formed catalytically active layer. Obtained catalyst is stable in temperature range 300-500° and ensures degree of CO into CO2 conversion in wide limits (from 37 to 97%).
EFFECT: increased catalyst stability.
2 dwg, 1 tbl, 12 ex
SUBSTANCE: method includes contact of oil factions with catalyst, which contains hydride of embedding type of metal, having reaction surface, with obtaining mixture catalyst-oil fractions; supply of radio-frequency (RF) or microwave energy, at least, to one from catalyst and mixture catalyst-oil fractions; formation of single-atom hydrogen on reaction surface of hydride of embedding type of metal; and interaction of oil fractions with single-atom hydrogen. In other version method includes: contact of oil fractions with catalyst, containing hydride of embedding type of metal, which has reaction surface, with obtaining mixture catalyst-oil fractions; where hydride of metal of embedding type is obtained by introduction of hydrogen into metal alloy, selected from group consisting of 1) A1-xMxT5-y-zByCz, where x=0,0-1.0; y=0.0-2.5; z=0.0-0.5; A=Mm (mishmetal); T=Ni; M= at least one from La, Pr or Ce; B=Co; C= at least one from Mn, Al or Cr; 2) A2-xMxT14-yCyDzB, where x=0.0-2.0; y=0.0-14; z=0.0-3.0; A=Nd; T=Fe; M= at least one from La, Pr or Ce; B=boron; C=Co; D= at least one from Cr, Ni or Mn; 3) A2-xMxT1-yBy, where x=0.0-0.5; y=0.0-0.5; A=Mg; T= at least one from Ni or Cu; M=La; B= at least one from Fe or Co; and 4) their combinations; and supply of microwave or RF energy to, at least, one from catalyst and mixture catalyst-oil fractions. In third version method includes: contact of oil fraction with catalyst, containing hydride of embedding type of metal, which has reaction surface, forming single-atom hydrogen; and interaction of oil fractions with single-atom hydrogen; where hydride of metal of embedding type is obtained by introduction of hydrogen into metal alloy, selected from group consisting of 1) A1-xT5-y-zByCz, where x=0.0-1.0; y=0.0-2.5; z=0.0-0.5; A=Mm (mishmetal); T=Ni; M= at least one from La, Pr or Ce; B=Co; C= at least one from Mn, Al or Cr; 2) A2-xMxT14-yCyDzB, where x=0.0-2.0; y=0.0-14; z=0.0-3.0; A=Nd; T=Fe; M= at least one from La, Pr or Ce; B=boron; C=Co; D= at least one from Cr, Ni or Mn; 3) A2-xMxT1-yBy with x=0.0-0.5; y=0.0-0.5; A=Mg; T= at least one from Ni or Cu; M=La; B= at least one from Fe or Co; and 4) their combinations.
EFFECT: increase of method efficiency.
31 cl, 8 ex, 10 tbl, 13 dwg
FIELD: chemical engineering.
SUBSTANCE: catalytic micro-passage plates comprises foam metals, metallic felt, and metallic cotton including catalyzer powder introduced into the pores of the metallic base. The number of passages ranges from 2 to 120 per 1 cm of length and depends on the size of the pores in metal. The width of the passage and width of the wall between the passages should be at lest five times larger than the size of pores in the metal used. The method of making the catalytic micro-passage plates is presented.
EFFECT: enhanced quality of catalytic plates.
11 cl, 5 ex
FIELD: hydrogenation-dehydrogenation catalysts.
SUBSTANCE: invention relates to methods of preparing alumino-chromium catalysts for dehydrogenation of paraffin hydrocarbons, preferably С2-С5, into corresponding olefins using low-temperature plasma. Plasma-chemical method for preparing catalyst comprises heat treatment of starting reactants taken in the form of aluminum and chromium carbonyl powders in the flow of low-temperature air plasma, said reactants being fed separately to the air plasma stream and to reactor in the form of argon-carried air sol in amount large enough to obtain catalyst containing 10-25% chromium oxide and 75-90% aluminum oxide. Resulting catalyst is cooled in the form of dust-gas stream to 30-50°C and recovered.
EFFECT: increased productivity of procedure, yield, and purity of target material, and increased catalyst activity.
FIELD: oxide catalyst preparation methods.
SUBSTANCE: invention relates to preparation of oxide-structure catalysts and provides a method for preparing oxide catalyst characterized by mixing two or more salt precursors of catalyst components followed by melting resulting mixture to achieve homogenous melt, cooling this melt to room temperature and subsequent decomposition of salts and calcination, wherein salt precursors of catalyst components are selected from d-metal nitrates (Ce and Y nitrates), melting of mixture is effected at 90 to 170°C in presence of ammonium nitrate used at ratio (2-10):1 to metal nitrate mixture, and decomposition of the melt into oxides is performed under effect of microwave emission. In a preferred embodiment of invention, microwave emission is used for 0.5-5 min at working frequency 2.45 GHz and power 600-1900 W. A method of preparing oxide catalysts involving introduction of oxide structure carrier into resulting melt at continuous stirring is also described.
EFFECT: enabled preparation of oxide catalysts and spinel-structure catalysts characterized by high degree of uniformity, lack of harmful impurities in catalyst composition, high-developed surface, and high heat resistance.
8 cl, 2 tbl
FIELD: petrochemical process catalysts.
SUBSTANCE: catalyst preparation method comprises: mixing high-silica Pentasil ZSM-5-type zeolite in ammonium form with distilled water, zinc nitrate, aluminum hydroxide, and boric acid; evaporating resulting mass; molding granules; drying; and treating granules with laser emission at power 40-50 W in three passes across monolayer of catalyst granules at scanning rate 800-1000 mm/min.
EFFECT: increased yield of aromatic hydrocarbons.
1 tbl, 11 ex
FIELD: woodworking and resin industries.
SUBSTANCE: invention concerns anthraquinone-based wood delignification catalyst, which can be used in vegetable stock cooking process involving alkaline technologies. Method comprises liquid-phase interaction of anthracene with oxidant in organic solvent followed by crystallization of anthracene. The latter operation is conducted for 1 to 10 min in presence of benzoic acid (consumption 0.01-0.3%) in ultrasonic field generated by ultrasonic emitter at acoustic power 0.6 kW and frequency 22 kHz.
EFFECT: increased catalytic activity of anthraquinone and reduced consumption of catalyst.
3 cl, 4 tbl, 4 ex
SUBSTANCE: described is catalyst for obtaining alkylene oxide by alkene epoxidation in steam phase, which contains applied by impregnation silver and at least one promoter on burnt heatproof solid carrier, and said carrier contains quantity of zirconium component, which is present in carrier mainly as zirconium silicate, and said heatproof carrier, with the exception of zirconium component at least on 95% by weight consists of aluminium alpha-oxide. Also described is method of said catalyst obtaining which includes: a) mixing of zirconium component, which is mainly present as zirconium silicate, with initial materials of carrier, which include aluminium oxide; b) burning of initial materials of carrier with added zirconium component at temperature less than 1540°C with formation of carrier, which includes aluminium alpha-oxide, where carrier includes zirconium component, present mainly as zirconium silicate; c) further deposition of silver and at least one promoter on carrier. In addition, described is method of catalyst application for alkyl oxide obtaining.
EFFECT: improvement of catalyst stability and activity.
23 cl, 10 tbl, 7 ex