The reaction element of heterogeneous-catalytic reactor
(57) Abstract:The reaction element of the reactor relates to a device for the implementation of heterogeneous catalytic reactions, particularly reactions of steam reforming of hydrocarbons. Made in the form of a highly porous material with a set of cells. Jumper cells highly porous material provided with a catalytically active coating, and the material of the reaction element occupies the entire volume of the reactor and is rigidly connected with its heat transfer walls. This design provides additional strength and allows to intensify the process of evaporation. 2 Il. The invention relates to a device for the implementation of heterogeneous catalytic reactions, particularly reactions of steam reforming of hydrocarbons. It allows you to utilize the heat of heat-stressed structural elements and to obtain a hydrogen-containing gases.The invention can be used in the construction of transport and stationary energy, chemical and other industries.Known catalytic element for the fixed catalyst layer in the channels of heterogeneous-catalytic reactor (author swollen as spatially deformed plate with a catalytic active layer on its surface. The plate is deformed relative to the larger of the axis of symmetry at an angle 90-180o. The ratio of the width of the plate to the diameter of the reactor is 0.1 to 0.7. Plate made of sheet material with high thermal conductivity that is loaded in the channel of heterogeneous-catalytic reactor and thereby form a porous permeable layer. Due to the fact that the plate is made from a material with high heat conductivity, the effective conductivity of the layer is high enough.However, the lack of hard contact plates with the wall of the reactor and between them does not allow full use of thermal conductivity of the material of the plates. Moreover, during operation of the reactor due to pollution free contacting surfaces of the contact between them will be reduced and thermal resistance to increase. Additionally, breach of contact will occur when the reactor is installed on the vehicle when the shaking and vibration of the device. All this will inevitably lead to a decrease in the intensity of heat and mass transfer.Also known reactionary element of the apparatus for catalytic conversion of methane from the description to the author's certificate of the USSR 1780826, IPC B 01 J 8 is with a gap relative to the inner surface of the pipe is fixed catalyst. The reaction element provided with a perforated insert coaxially and with a gap that is installed on the catalyst.The outer surface of the insert provided with a catalytically active coating. The coating can be performed by plasma spraying powder of metallic Nickel on the surface of the insert. The catalytically active coating of the insert allows to intensify the total heat transfer from the outer pipe to insert and to the flow of the reacting mixture and to intensify the process of thermochemical accumulation of thermal energy through the creation of the cross-section of the annular channel of the optimal profiles of temperature and concentration fields.In this analogue warmth to the surface of the catalyst and the catalytic surface of the perforated insert for carrying out a chemical reaction is served only by convection from the heated wall. The intensity of heat transfer in comparison with the stated reaction element of the low.Of all known analogues closest to the proposed invention to the technical essence and the achieved effect when using it is a reactionary element, known from the description to the author's testimony 1710117, IPC B stny reactionary element heterogeneous catalytic reactor with a fixed catalyst bed in the form of metal mesh tube, mounted on the frame coaxially of the reaction tube. Metal mesh tube composed of a series of successive layers with a catalytically active layer and increasing from the inner layer to the outer step of the cell.Reactionary elements are loaded into the reaction tube in an amount necessary for the desired degree of completion of the reaction of steam reforming. Due to the fact that the reaction element is made of a set of grids with high conductivity, temperature gradient on the layer of catalyst is minimal, despite the high indeterminate reaction.The temperature of the inner layers of mesh reactionary element practically does not differ from the temperature of the outer layer. The efficiency of the internal layers of the catalyst is comparable with the efficiency of the outer layers.Intensifitsirovany heat transfer from the wall of the reaction tube is due to the layered execution of the reaction element.However, in the prototype there is a cascade of thermal resistances from the heated wall to gas, from gas to the outer surface of the mesh tube from the outer surface to the inner surface of the pores. The heat transfer from the reaction heated tritace high. In addition, the gap between the reaction tube and the reaction element is not possible to use the latter as a power of the structural element.The technical task to be solved by the invention is a significant intensification of the process of heat and mass transfer and ensuring minimal temperature gradients in the reactor, as well as providing additional structural strength.Declared reactionary element, as a prototype, is a porous permeable material with a set of cells bounded by the walls of heterogeneous catalytic reactor.Unlike the prototype, the reaction element is designed as a highly porous cellular material (ITAM), three-dimensional cell which is formed by a metal edge ridges, creating a rigid frame reactionary element. Jumpers have a catalytically active coating. Highly porous cellular material is rigidly connected with the heat transfer wall of heterogeneous-catalytic reactor.The stated set of essential features when using the invention ensures the supply of heat to the catalytically active coating m the strict frame of the reaction element. This allows significantly intensify the heat transfer in a chemical reaction and to provide a minimum temperature gradients in the reactor.The invention is illustrated by drawings, where:
- Fig.1 shows a cross-section of heterogeneous-catalytic reactor rectangular cross-section with the stated reaction element;
- Fig.2 - site And in a larger view.Declare the reaction element, as a prototype, is a porous permeable material with a set of cells 1, bounded by the walls 2 heterogeneous catalytic reactor. Unlike the prototype, the reaction element is designed as a highly porous cellular material (ITAM), rigidly attached (soldering, welding, etc.,) to the walls of the reactor. ITEM has a three-dimensional pentagondodecahedron three-dimensional structure, cell 1 which is formed of metal ribs-jumpers 3, creating a rigid frame reactionary element. Metal jumper 3 have high conductivity and are catalytically active coating 4.Heterogeneous catalytic reactor with the reaction element operates as follows.The original gas-vapor mixture with 1 (1-5) mm and an open porosity of 0.80-0,98 has a low hydraulic resistance to flow of a chemically reactive gas, and the high conductivity metal jumpers 3 and homogeneity of ITEM provide uniform volume of reactor heat transfer from the heated wall 2. Necessary for carrying out the endothermic reaction heat is supplied to the catalytically active coating 4 is not only due to the convective heat transfer, but also by conduction to the frame of the reactionary element that allows significantly intensify the process of heat transfer and to ensure minimal temperature gradients in the reactor.The rigid connection of the reaction element with walls 2 heterogeneous-catalytic reactor gives his design for extra strength, due to the high mechanical properties of ITEM due to the three-dimensional structure. The reaction element of ITEM may be made of any shape (round, square, etc.,) depending on the shape of the surface to be cooled.The present invention can be used for the disposal of heat loss through the walls of the apparatus, and with the leaving gases. Tallapragada part construction is one of the walls of heterogeneous-catalytic reactor, which is, for example, kleweno heat Q=6,6 MJ/kg, equal to the heat of reaction, and the resulting molecular hydrogen H2being environmentally friendly fuel. Held in our company calculations and experimental work confirmed the possibility of removing large heat loads from heat-stressed structural elements. The reaction element heterogeneous catalytic reactor, made in the form of a highly porous material with a set of cells, wherein the jumper cells highly porous material provided with a catalytically active coating, and the material of the reaction element occupies the entire volume of the reactor and is rigidly connected with its heat transfer walls.
FIELD: production of honeycomb substrates for catalyst converters for two-wheeled or diesel vehicles.
SUBSTANCE: the invention is dealt with production of honeycomb substrates made out metal sheets piled or rolled in a package and minimized to the honeycomb elements used first of all as honeycomb substrates for catalyst converters in the systems of exhaust gas (EG) neutralization. There is a description of a honeycomb element (1) first of all as a honeycomb substrate for a catalyst converter for systems of two-wheeled vehicles exhaust gas neutralization. The honeycomb substrate for catalyst converter consists of some layers of metal sheets (2, 3) packed as a package or minimized in a roll, which are at least on separate sections are structured or profiled in such a manner, that they form for EG flowing channels (4). At that the metal sheets (2, 3) represent the sheets of high-quality steel of more than 0.08 mm thick with a share of aluminum from 6 up to 12 mass % multiplied by 0.02 mm and divide by "d" - thickness of the metal sheets (2, 3). The technical result - a possibility to use metal sheets depending on the share of aluminum in them and their thickness, that allows to use the sheets taken from production process of manufacture of a material subjected to a hot aluminization.
EFFECT: the invention ensures a possibility to use metal sheets for the purpose depending on the share of aluminum in them and their thickness.
5 cl, 1 dwg
FIELD: gas treatment catalysts.
SUBSTANCE: invention, in particular, relates to internal combustion engine exhaust gas neutralizers. Method of invention comprises rolling refractory metallic tape into block by way of overlapping its smooth and corrugated sides to form channels, performing ultrasound-assisted chemical cleaning of thus rolled tape in alkali solution followed by joining alternate layers of metallic tape with each other by diffusion welding in vacuo within a range of 5·10-5-1·10-5 mm Hg using stepwise heating to 1250 ± 10°С and isothermal exposure to this temperature for 12-17 min to form monolithic structure consisting of triangular and trapezoidal channel at density up to 600 channels per 1 inch2. Invention further describes carrier for catalytic exhaust gas neutralizers representing monolithic metallic structure in the form of cylindrical block or block with oval cross-section, which block consists of parallel channels, 200-600 per 1 inch2, density of channels varying along the cross-section of carrier: from center and extending to 0.55 0,7 diameter if cylindrical block or large axis of oval cross-section, density of channels is 400-600 per 1 inch2 and farther it decreases to 200 or 400 channel/inch2, respectively.
EFFECT: simplified manufacture technology and increased strength of monolithic cellular structure.
4 cl, 4 dwg, 1 tbl
FIELD: heterogeneous catalysts.
SUBSTANCE: catalyst contains porous carrier, buffer layer, interphase layer, and catalytically active layer on the surface wherein carrier has average pore size from 1 to 1000 μm and is selected from foam, felt, and combination thereof. Buffer layer is located between carrier and interphase layer and the latter between catalytically active layer and buffer layer. Catalyst preparation process comprises precipitation of buffer layer from vapor phase onto porous carrier and precipitation of interphase layer onto buffer layer. Catalytic processes involving the catalyst and relevant apparatus are also described.
EFFECT: improved heat expansion coefficients, resistance to temperature variation, and reduced side reactions such as coking.
55 cl, 4 dwg
FIELD: production of non-metallic elements.
SUBSTANCE: reactor comprises means for supplying hydrocarbon raw material and water vapor, means for discharging the product, and porous metallic load-bearing structure that receives catalyzer of reforming with water vapor. The porous load-bearing metallic structure is secured to the inner wall of the reactor by means of gluing or diffusion bounding.
EFFECT: improved functional capabilities.
5 cl, 2 dwg
FIELD: chemical industry; trapping nitric oxides and other harmful substances from the waste gases.
SUBSTANCE: the invention is pertaining to chemical industry and is used for trapping nitric oxides and other harmful substances from the waste gases. The offered reactor contains a body with the connection pipes for introduction of the initial reactants. Inside the body there is a modular catalyst of a cellular structure. The through channels of the catalyst in respect to the incoming stream are oriented at an angel of 90°. The hydraulic diameter of the through channels of the different geometrical shape, beginning from the first channel, along the stream run is monotonically enlarging, reaching the ratio of the hydraulic diameters of the last channel to the first one first channel of no more than 1.5. No more than 1/6-th of the height from the bottom of the block the modular catalyst of the cellular structure has a mesh-cellular structure with a mesh size from 1.5 up to 3 mm and a specific surface up to 8...10 m2/g. The given engineering solution ensures an increased access to the internal surface of the bottom part of the modular catalyst of the cellular structure and its complete participation in operation.
EFFECT: the invention ensures an increased access to the internal surface of the bottom part of the modular catalyst of the cellular structure and its complete participation in operation.
FIELD: catalyst preparation.
SUBSTANCE: invention relates to supported catalysts and provides a method for preparing catalyst-containing solid product comprising step, wherein ceramic carrier is applied onto metallic surface, and depositing catalytically active material onto ceramic carrier, which was preliminarily coated with supporting porous metallic material, ceramic carrier being applied onto and/or into supporting porous metallic material. Invention also describes device used in preparation of catalyst-containing solid product for applying supporting porous material onto inside or outside metallic surfaces of the hollow body.
EFFECT: increased stability of catalyst.
7 cl, 2 dwg
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to technology for preparing caprolactam by the cyclization reaction of derivatives of aminocaproic acid. Method is carried out by cyclizing hydrolysis of compound chosen from the group comprising aminocaproic acid esters or amides, or their mixtures. The process is carried out in the presence of water, in vapor phase at temperature 200-450°C in the presence of a solid catalyst comprising of aluminum oxide that comprises at least one macroporosity with pores volume corresponding to pores with diameter above 500 Å taken in the concentration 5 ml/100 g of above. Preferably, the specific square of catalyst particles is above 10 m2/g and the total volume of pores is 10 ml/100 g or above wherein pores volume corresponds to pores with diameter above 500 Å is 10 ml/100 g or above. Invention provides improving the process indices due to the improved properties of the solid catalyst.
EFFECT: improved preparing method.
5 cl, 2 ex
FIELD: catalyst preparation methods.
SUBSTANCE: method involves preparing porous carrier and forming catalyst layer by impregnation of carrier with aqueous solution of transition group metal salts followed by drying and calcination. Porous catalyst carrier is a porous substrate of organic polymer material: polyurethane or polypropylene, which is dipped into aqueous suspension of powdered metal selected from metals having magnetic susceptibility χ from 3.6·106 to 150·106 Gs·e/g: iron, cobalt, chromium, nickel, or alloys thereof, or vanadium and polyvinylacetate glue as binder until leaving of air from substrate is completed, after which carrier blank is dried at ambient temperature and then fired at 750°C in vacuum oven and caked at 900-1300°C. Caked blank is molded and then subjected to rolling of outside surface to produce carrier having variable-density structure with density maximum located on emitting area. Formation of catalyst layer is achieved by multiple impregnations of the carrier with aqueous solution of acetates or sulfates of transition group metals: iron, cobalt, chromium, nickel, or alloys thereof in alternative order with dryings at ambient temperature and calcinations to produced catalyst bed 50-80 μm in thickness. In another embodiment of invention, formation of catalyst layer on carrier is accomplished by placing carrier in oven followed by forcing transition group metal carbonate vapors into oven for 60-120 min while gradually raising oven temperature to 850°C until layer of catalyst is grown up to its thickness 50-80 μm.
EFFECT: improved quality of catalyst and reduced its hydrodynamic resistance.
8 cl, 1 tbl, 3 ex
FIELD: catalyst preparation methods.
SUBSTANCE: invention relates to a method for preparing catalyst and to catalyst no honeycomb-structure block ceramic and metallic carrier. Preparation procedure includes preliminarily calcining inert honeycomb block carrier and simultaneously applying onto its surface intermediate coating composed of modified alumina and active phase of one or several platinum group metals from water-alcohol suspension containing, wt %: boehmite 15-30, aluminum nitrate 1-2, cerium nitrate 4-8, 25% ammonium hydroxide solution 10-20, one or several precipitate group metal salts (calculated as metals) 0.020-0.052, water-to-alcohol weight ratio being 1:5 to 1:10; drying; and reduction. Thus prepared catalyst has following characteristics: specific coating area 100-200 m2/g, Al2O3 content 5-13%, CeO2 content 0.5-1,3%, active phase (on conversion to platinum group metals) 0.12-0.26%.
EFFECT: simplified technology due to reduced number of stages, accelerated operation, and high-efficiency catalyst.
5 cl, 1 tbl, 10 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for liquid-phase catalytic alkylation of aromatic amines. Method involves alkylation reaction of aromatic amines in the presence of hydrogen and lower alcohols at temperature 50-70°C on a heterogeneous catalyst. The distinctive specificity of method represents alkylation of amine with formaldehyde solution in reactor with reaction zone filled with catalyst consisting of aluminum oxide-base block high-porous cellular carrier with porosity value 7-95%, not less, and palladium as an active component with the mass content = 1.3-2%. As a rule, in the alkylation process catalyst prepared by impregnation of block high-porous cellular carrier with palladium salts treated preliminary in the constant magnetic field is used. Usually, in the case of alkylation of aniline and for preferential synthesis of monomethylaniline the molar ratio aniline to formaldehyde solution = 1.6:(1.1-1.6) is used. Proposed method as compared with the nearest analog in the case of alkylation of aniline provides preparing monomethylaniline mainly, to decrease the content of palladium as an active component in catalyst and to decrease the reaction pressure and hydraulic resistance of catalytic layer also. Invention can be used in producing antiknock additives to motor fuels (gasolines).
EFFECT: improved alkylation method.
3 cl, 4 ex