Metal-based catalyst carrier (versions) and method of its preparation (versions)
FIELD: technical chemistry; catalyst carriers for various heterogeneous processes in chemical industry.
SUBSTANCE: proposed carrier has metal base made from chromium and aluminum alloy and/or metallic chromium and coat made from chromium of aluminum oxides or oxides of chromium, aluminum, rare-earth elements or mixture of them. Method of preparation of carrier includes forming of metal powder containing aluminum and other powder-like components and calcination of carrier at solid phase sintering point; used as additional component of metal powder is powder-like chromium; mixture thus obtained is subjected to mechanical activation and is placed in mold accessible for water vapor, after which it is subjected to hydro-thermal treatment and molded product is withdrawn from mold, dried and calcined at respective temperature; then additional layer of aluminum and rare-earth elements oxides or mixture of solutions and suspensions is applied on calcined product followed by drying and calcination.
EFFECT: increased specific surface; enhanced heat resistance of carrier.
8 cl, 1 tbl, 5 ex
The invention relates to the field of technical chemistry, namely, carriers for catalysts that can be used in various heterogeneous catalytic processes in the chemical industry, such as full and partial oxidation of hydrocarbons, steam reforming and others, as well as in the energy and automotive industries.
It is known that the use as a carrier for catalysts of metals having high mechanical strength and thermal conductivity, reduces mechanical destruction of the catalyst and to reduce the possibility of local overheating, as well as to produce catalysts in the form of complex cellular structures. The most common problem for metals used as a carrier for catalysts complex forms, is their low specific surface area, which significantly reduces the activity of the catalysts prepared on the basis of such media. To increase the specific surface area of the carriers in metals can cause a highly porous layer of ceramic oxide pre - or together with the active component (catalyst). This layer provides a high dispersion of the active component and the adhesion layer to the metal surface. Thus, the known system, the precursor and the catalyst based on it containing a highly porous layer deposited on the less porous the th or non-porous media from a non-aqueous solvent, containing oxide [US 5472927, B 01 J 021/08, 05.12.1995].
Known thermally integrated monolith containing oxide coating placed on a thin metal plate, forming palikoista structure [WO 0016740, a 61 K 7/50, 23.08.2001]. However, for such high-temperature processes such as combustion of fuels or partial oxidation of hydrocarbons to synthesis gas, an important characteristic is the stability of the catalyst to effect the reaction medium, the time of operation ("life") catalyst [US 4771029, B 01 J 21/04, 13.09.1988]. In particular, the difference of coefficients of thermal expansion of the porous ceramic layer and the metal leads to breakaway from the first surface of the second at high temperatures.
More resistant to high temperatures (heat-resistant) solid media (catalysts) on a metal base formed by applying an intermediate layer between the metal substrate and highly porous oxide coating. These layers not only reduce peeling, but also reduce oxidation of the metal, which is also important for monolithic blocks. Thus, the known method of gas-phase eletrownia cell blocks, made of thin tape-based Fe-Cr-Al alloys type HU-HU at a temperature thermochemical processing >1050°in the saturating mixture containing Al0and AlF [SU 2080458, F 01 N 3/28, 27.05.1997]. The method allows to obtain a dense oxide coating, improving heat resistance 3-10 times. However, eletrownia ready block leads to non-uniformity of the coating on the height of the block [Kinetics and catalysis, 1998, t, B.5: Sevasitan, Cal, Weasle, Anildigital, Ibogaine "improving the heat resistance of the metal blocks, carriers of the catalyst by the method of gas-phase eletrownia", s-717]. This reduces the adhesion of highly porous layer to the substrate and reduces the activity produced from this catalyst carrier.
Also known methods based on cultivation of the intermediate oxide layer from the material of the metal substrate. Thus, the known method of obtaining a dense oxide composite on the surface of aluminum metal by anodic spark oxidation [SU 2103057, B 01 J 21/02, 11.07.1996]. Then on the resulting carrier is applied jointly or separately porous oxides and platinum metals. However, the resulting intermediate oxide layer is porous and consists of a system of intersecting cylindrical macropores with a diameter of from 0.5 to 10 μm [MRS n.497: S.F.Tikhov, G.V.Chernykh, V.A.Sadykov, A.N.Salanov, S.V.Tsybulya, G.M.Alikina, V.F.Lysov "New type of catalytic material based upon alumina epitaxially grown onto thin aluminum foil" p.71-76]. This reduces the stability of the catalyst.
The closest in composition is a carrier selected n the mi as a prototype, consisting of Fe-20Cr-5Al alloy and coating consisting of a sintered powder from a mixture containing, wt.%: 50 Fe and Al with 50 particle size 36-45 mm [US 4783436, B 01 J 21/04, 08.11.1988]. Sintering at high temperature leads to partial oxidation of the metallic base. In particular, in the alloy Fe-Cr-Al aluminium smelted at the surface of the foil and is oxidized, forming an oxide with a structure of corundum the form of elongated crystals. Partially oxidized and the powder, forming additional plates of iron oxide. As a result, the coating is not continuous oxide layer, and a mixed metal oxide composite with a very low specific surface (0.1 m2/g). This leads to the fact that the amount of active component applied from solutions on such media, small and activity derived from such catalysts carriers is low.
The invention solves the problem of increasing the specific surface of the metal carrier while maintaining high heat resistance.
The problem is solved by the composition of the catalyst carrier, which consists of a metal base containing alloys of chromium and aluminum and/or metal chromium, and coatings, which are formed by the oxides of chromium and aluminum (the first option), or the coating formed by the oxides of chromium and aluminum, rare earths or mixtures thereof (the second option). The content of the metal base is in the media is not less than 12.0 wt.%.
The problem is solved through the use of the metallic base of the carrier metal chromium, and alloys of chromium and aluminum as on the basis of solid solutions of aluminum in chrome, and on the basis of intermetallic compounds chromium and aluminium certain structure and stoichiometry (CrAl7, Cr2Al11, CrAl4, Cr4Al9, Cr5Al8, Cr2Al) and other [Pasang "the structure of double alloys", 1973, M.: metallurgy, p.55-57]. The total content of the metal phase (basics) in the medium is not less than 12.0 wt.%, preferably 12,3 reached 98.9 wt.%. As coverage in the media use the oxides of chromium and aluminum, the same structure of corundum with high thermostability. The chromium oxides have moderate activity in oxidation reactions involving hydrocarbons, which increases the activity of the platinum metals when they are applied to the media. A relatively high content of aluminum oxide provides a relatively large porosity of the received media.
The coating of the carrier (the second option) could contain oxides of rare earth elements, or mixtures thereof, which allows to significantly increase their thermostability and activity produced from these catalysts at high temperatures. The term "rare earth elements" is used in a broad sense, as implying f elements, and the side elements IIIb group of the Periodic table (La, Y). The total content of the metal phase (basics) in this medium is not less than 12.0 wt.%, preferably, 12,0-to 98.5 wt.%.
The task is also solved by a method of preparation of the proposed media.
Noted previously, the methods include use as a basis metal strip, which does not allow to obtain media with high specific surface area and porosity without causing additional highly porous substrate [WO 0016740, a 61 K 7/50, 23.08.2001; U.S. Pat. RF 2080458, F 01 N 3/28, 27.05.1997; MRS, n.497: S.F.Tikhov, G.V.Chemykh, V.A.Sadykov, A.N.Salanov, S.V.Tsybulya, G.M.Alikina, V.F.Lysov "New type of catalytic material based upon alumina epitaxially grown onto thin aluminum foil" p.71-76].
More porous composite materials can be obtained from the powdered components. Thus, the known method of preparing the composite material-based aluminium-containing alloy, which comprises a mixture of fibers of alumina and silicon, copper, magnesium, Nickel with molten aluminum in an inert atmosphere [US 41521449, With 22 21/10, 01.05.1979]. This method does not allow to obtain porous composites.
Also known a method of obtaining (ceramometal) cermet grade containing metal particles (less than 30 wt.%) in the matrix of aluminum oxide, deposition from solutions containing aluminum compounds and metal from the group iron, chromium, molyb the ena and others, with subsequent high-temperature annealing and recovery in hydrogen at 1050°With [US 5462903, 04 35/117, 31.10.911995]. This method allows to obtain composite materials with a specific surface area up to 5 m2/, However, the content of the metal phase in the composite is small.
There is also known a method of preparation of the active hromsoderzhashchej composition comprising a mixture of 0.1 to 100 mol.% (in terms of metal) chromium or chromium compounds, various metals, and the material forming the matrix-based alkoxides of aluminum and other metals in an amount of not less than 30 wt.% [WO 0160515, B 01 J 37/00, 23.08.2001]. To obtain a mechanically stable carrier method includes the mandatory annealing in a reducing or inert atmosphere at high temperatures, which significantly complicates the manufacturing process and does not allow to obtain media with a high content of metal, which increases the conductivity of the media.
In the patent [US 4783436, B 01 J 21/04, 08.11.1988], selected as a prototype and method of preparation of the medium described method of preparing a catalyst carrier-based metal having an oxide coating, comprising mixing a metal powder consisting of an alloy of iron and aluminum, marking the metal base, as in examples foil of alloy is Fe-Cr-Al, and calcination of the carrier at a temperature providing a sintering powder with a metal base. This method provides a carrier with a high content of the metal phase, but a small specific surface area.
The proposed method for the preparation of the medium on the metal base includes forming a metal powder containing aluminum and other powdered components, and the roasting carrier when the sintering temperature of the solid phase, as an additional component of the metal powder used powdered chromium, the resulting mixture is subjected to mechanisatie and placed in the mold, available for water vapor, and subjected to hydrothermal treatment, is removed from the mold molded product, which is then dried and calcined at an appropriate temperature (first option), then applied to the calcined product additional layer of aluminum oxide and rare earth elements, or mixtures of solutions or suspensions with subsequent drying and calcination (the second option). The ratio of chromium to aluminum metal powder can be changed within, wt. share: from 75:25 to 99:1.
In the present invention use only the powder components in the form of a mechanical mixture of powders of aluminum and chromium, which is subjected to mechanisatie in energy is abrajano planetary mill during acceleration of the grinding bodies 600-1000 m/s 2[SU 2118669, With 22 33/02, D 22 F 3/16, 20.08.1996]. The ratio of Cr:Al powder ranges (wt. share): from 75:25 to 99:1. At higher content of aluminum powder in the process of mechanisatie is the spontaneous oxidation of aluminum. Then the powder is placed in the mold, providing access water vapor, and treated under hydrothermal conditions. As a result, the adhesion of the powder in a mechanically stable monolith, which is extracted from the mold, dried and calcined in air. The result is a metallic phase based on chromium or chromium and its alloys, which are very resistant to oxidation in air up to 1100°C. On the surface of the metal particles is formed by a coating consisting of oxides of chromium and aluminum with the structure of corundum and providing a sufficiently high specific surface area. Preliminary mechanical activation facilitates the formation of alloys of chromium and aluminum, after annealing. Hydrothermal processing provides the setting in a mechanically stable monolith without calcinations at high temperatures in a reducing or inert atmosphere and contributes to the formation of high specific surface coverage of the carrier. As additional stages may be used, the carrier impregnated with solutions or suspensions containing compounds is s rare earth elements or their mixtures or aluminum and rare earth elements, or mixtures thereof, followed by drying and calcination.
Technical result achieved - high specific surface of a metal carrier and its high resistance to heat.
The essence of the invention is illustrated by the following examples.
Example 1. Chromium powder is mixed with aluminum powder in the ratio (wt. shares) 75:25, is subjected to mechanisatie for 1 min. the resulting powder was placed in a mold made of stainless steel and is subjected to hydrothermal treatment. Mechanically strong monolith is removed from the mold, dried and calcined at 1100°C for 4 h in air. The media contains phase of chromium oxide, aluminum oxide and metallic chromium. The content of the metal phase of 12.8 wt.%.
Example 1A (the second option). Similar to example 1. Characterized in that on the carrier in addition put a cerium oxide from the solution, followed by drying and calcination at 1100°C. the Medium contains phase of chromium oxide, aluminum oxide, cerium oxide and metallic chromium. The content of the metal phase to 12.0 wt.%.
Example 2. Chromium powder is mixed with aluminum powder in the ratio (wt. shares) 80:20, is subjected to mechanisatie within 3 minutes the resulting powder was placed in a mold of largescale and subjected to hydrothermal treatment. Mechanically strong monolith is removed from the mold, dried and calcined at 1100°C for 4 h in air. The media which contains the phase of chromium oxide, aluminum oxide, chromium metal and chromium alloys and aluminum. The content of the metal phase to 12.3 wt.%.
Example 3. Chromium powder is mixed with aluminum powder in the ratio (wt. shares) 80:20, is subjected to mechanisatie within 5 minutes the resulting powder was placed in a mold made of stainless steel and is subjected to hydrothermal treatment. Mechanically strong monolith is removed from the mold, dried and calcined at 1100°C for 4 h in air. The media contains phase of chromium oxide, aluminum oxide, metallic chromium and chromium alloys and aluminum. The content of the metal phase to 35.0 wt.%.
Example 4. Chromium powder is mixed with aluminum powder in the ratio (wt. shares) 80:20, is subjected to mechanisatie within 10 minutes the resulting powder was placed in a mold made of stainless steel and is subjected to hydrothermal treatment. Mechanically strong monolith is removed from the mold, dried and calcined at 1100°C for 4 h in air. The media contains phase of chromium oxide, aluminum oxide, metallic chromium and chromium alloys and aluminum. The content of the metal phase of 74.0 wt.%.
Example 5. Chromium powder is mixed with aluminum powder in the ratio (wt. shares) 99:1, put mechanisatie within 10 minutes the resulting powder was placed in a mold of largescale and subjected to hydrothermal treatment. Mechanical the ski durable monolith is removed from the mold, dried and calcined at 1100°C for 4 h in air. The media contains phase of chromium oxide, aluminum oxide, metallic chromium and chromium alloys and aluminum. The content of the metal phase that 98.9 wt.%.
Example 5A (the second option). Similar to example 5. Characterized in that on the carrier in addition put the oxides of cerium, lanthanum and aluminum in the slurry, followed by drying and calcination at 1100°C. the Medium contains phase of chromium oxide, aluminum oxide, oxides of rare earth elements, metal chromium and chromium alloys and aluminum. The content of the metal phase to 98.5 wt.%.
The basic properties of the obtained media presented in the table.
As can be seen from the table, the specific surface area obtained media is 0.5-1.9 m2/year the Total volume available for the gas phase then is 0,27-0,11 cm3/, While the share of pore size less than 0.1 μm is 2.1-25,0% vol. of the total number of available pores, which provides a high diffusive permeability of the received media. The most optimal from the point of view of mechanical strength, specific surface area and porous structure are the media containing 12,3-74,0 wt.% the metal phase.
Basic properties of the catalyst carrier.
|No.||The composition of the powder, by weight. Rel. Cr:Al||Time megachilidae powder, min||The phase composition of the metallic base||The coating composition||The content of the metallic base in the media, wt.%||The specific surface the terrain of media, m2/g||Total pore volume, cm3/g||The amount of pore size <1000Åcm3/g||The strength of granules, MPa|
1. Catalyst carrier consisting of a metal base, chromium, and coatings containing aluminum, wherein the metal base includes alloys of chromium and aluminum and/or metallic chromium, and the coating formed by the oxides of chromium and aluminum.
2. The carrier according to claim 1, characterized in that the content of the metallic base in the medium is not less than 12.0 wt.%.
3. The method of preparation of the catalyst carrier on a metal basis, including the formation of a metal powder containing aluminum and an additional powder component, the roasting carrier when the sintering temperature of the solid phase, characterized in that as an additional component of the metal powder used powdered chromium, the resulting mixture is subjected to mechanisatie, then poluchenno the mixture placed in the mold, available for water vapor, and subjected to hydrothermal treatment, is removed from the mold molded product, which is then calcined at an appropriate temperature.
4. The method according to claim 3, characterized in that the ratio of chromium to aluminum metal powder can be changed within, parts by weight: 75:25÷99:1.
5. Catalyst carrier consisting of a metal base, chromium, and coatings containing aluminum, wherein the metal base includes alloys of chromium and aluminum and/or metallic chromium, and the coating formed by the oxides of chromium and aluminum, rare earths or mixtures thereof.
6. The carrier according to claim 5, characterized in that the content of the metallic base in the medium is not less than 12.0 wt.%.
7. The method of preparation of the catalyst carrier on a metal basis, including the formation of a metal powder containing aluminum and an additional powder component, and the roasting carrier when the sintering temperature of the solid phase, characterized in that as an additional component of the metal powder used powdered chromium, the resulting mixture is subjected to mechanisatie and placed in the mold, available for water vapor, and subjected to hydrothermal treatment, is removed from the mold molded product, which is then su is at and calcined at an appropriate temperature, then put on the calcined product additional layer of aluminum oxide and rare earth elements or their compounds from solutions or suspensions, followed by drying and calcination.
8. The method according to claim 7, characterized in that the ratio of chromium to aluminum metal powder can be changed within, parts by weight: 75:25÷99:1.
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 manufacture processes.
SUBSTANCE: invention relates to manufacture of catalysts useful in various chemical and petrochemical areas and provides catalyst carrier comprising alumina and aluminum wherein fraction of pores above 0.1 μm in size constitutes 10.0-88.5% based on the total volume of pores constituting 0.10 to 0.88 cm3 per 1 g carrier. Preparation of carrier comprises molding blanc from aluminum powder and inorganic additive, oxidation, and caking, said inorganic additive being product of thermochemical activation of amorphous hydrargillite Al2O3·nH2O.
EFFECT: optimized specific surface, mechanical strength, and apparent density of carrier.
2 cl, 1 dwg, 1 tbl, 9 ex
FIELD: production of catalysts on base of compounds of copper, zinc and aluminum for low-temperature conversion of carbon oxide with water steam; chemical, and petrochemical industries; production of ammonia and hydrogen.
SUBSTANCE: proposed method consists in mixing the solution of ammonia-carbonate complex of copper with solution of ammonia-carbonate complex of zinc and with oxide or hydroxide of aluminum; suspension thus obtained is heated to 40-50°C, then it is subjected to stirring continued for 1-2 h, after which temperature is raised to 85-97°C and purge gas is introduced, for example nitrogen or carbon dioxide and suspension is mixed at solid-to-liquid ratio of 1:(2.0-4.0); sediment is removed; mixture is dried, calcined and liquid stabilizing additives are introduced into calcined mass at solid-to-liquid ratio of 1: (0.2-1.0) and 1-1.5 mass-% of graphite is added; mixture is stirred, granulated and pelletized. Used as stabilizing additives are chromic, nitric or oxalic acids, or their salts, or carbamide.
EFFECT: enhanced activity and thermal stability.
2 cl, 1 tbl, 20 ex
FIELD: gas treatment catalyst.
SUBSTANCE: invention relates to treatment of sulfur-containing emission gases according to Claus method and can find use in enterprises of gas, petroleum, and chemical industries as well as of ferrous and nonferrous metallurgy. Task of invention was to provide a catalyst with elevated strength and elevated activity simultaneously in three Claus process reactions: oxidation of hydrogen sulfide with sulfur dioxide; oxidation of hydrogen sulfide with sulfur dioxide in presence of oxygen; and carbonyl sulfide hydrolysis. The task is solved with the aid of sulfur-removing catalyst including titanium oxide, vanadium oxide, calcium sulfate and modifying metal compound. The latter is at least one of metal compounds selected from alkali metal (Me = K, Na, Cs or mixture thereof) oxides take at following proportions, wt %: V2O5 5.5-10.0, CaSO4 10.0-20.0, Me2O 0.1-2.0, provided that weight ratio Me2O/V2O5 = 0.01-0.36. Catalyst contains pores 10-40 nm in size in amount 50-70%. Preparation of catalyst comprises preparation of catalyst mass, extrusion, drying, and calcinations at temperature not higher than 400°C.
EFFECT: simplified catalyst preparation procedure, which is wasteless, energy efficient, and environmentally friendly.
6 cl, 2 tbl, 2 ex
FIELD: petrochemical process catalysts.
SUBSTANCE: non-oxidative conversion of methane becomes more efficient owing to increased yield of desired product obtained on Mo-containing zeolite catalyst prepared by modifying zeolite with molybdenum in solid phase. In particular, molybdenum in the form of nano-size powder (obtained according to electric explosion technique in argon atmosphere) is mixed with ZSM-type zeolite and mixture is then calcined resulting in catalyst with molybdenum level 0.5 to 6.0%.
EFFECT: increased catalyst activity in methane-to-aromatic hydrocarbons conversion process.
1 tbl, 7 ex
FIELD: chemistry of polymers, chemical technology, catalysts.
SUBSTANCE: invention relates to a method for preparing a catalyst used in polymerization of butadiene and copolymerization of butadiene with coupled dines. Method involves interaction of components comprising the compound of rare-earth element, diisobutyl aluminum hydride, triisobutyl aluminum, alkyl aluminum halide and coupled diene. Firstly, method involves mixing rare-earth element and coupled diene solutions with diisobutyl aluminum hydride solution, and the mixture is kept for 10-30 min at stirring, and then triisobutyl aluminum and alkyl aluminum halide solutions are added. After mixing all components the mixture is kept for 10-15 h in the following mole ratio of components: rare-earth element : diisobutyl aluminum hydride : triisobutyl aluminum : alkyl aluminum halide : coupled diene = 1:(3-12):(6-12):(1.5-3):(2-20), respectively, wherein rare-earth element carboxylate or alcoholate is used as a source of rare-earth element. Invention provides preparing the high-effective catalyst allowing preparing highly stereoregular polybutadiene and butadiene copolymer with the couples diene with simultaneous reducing the range of molecular-mass disposition by 3-3.5 times.
EFFECT: improved preparing method.
FIELD: polymerization catalysts.
SUBSTANCE: catalyst preparation involves interaction of rare-earth element compound, conjugated diene, and diisobutylaluminum hydride followed by ageing of reaction mixture for 10-30 min, adding tetraisobutyl-dialumoxane and alkylaluminum hydroxide at molar ratio 1:(2-20):(3-12):(6-12):(1.5-3), respectively, and ageing resulting mixture for 10-15 h. Diene utilized is in the process is pyperilene or isoprene and rare-earth element compound is rare-earth element carboxylate or alcoholate. Catalyst can, in particular, find use in production of cis-1,4-polydienes.
EFFECT: achieved preparation of high-efficiency catalyst enabling production of highly stereospecific polybutadiene or butadiene/isoprene or butadiene/pyperilene copolymers at narrower molecular mass distribution.
FIELD: organic synthesis catalysts.
SUBSTANCE: method of preparing catalyst based on high-silica zeolite comprises calcination of zeolite and treating it with ammonium salt solutions at 160-200°C followed by mixing with binder, drying, and calcination. High-silica zeolite utilized is ZSM-5 zeolite, which is treated with aqueous ammonium solutions until degree of Na+ cation substitution above 99% is attained.
EFFECT: increased catalytic activity and selectivity in benzene-ethylene alkylation process.
1 tbl, 6 ex
FIELD: organic synthesis catalysts.
SUBSTANCE: method of preparing catalyst based on high-silica zeolite comprises calcination of zeolite and treating it with ammonium salt solutions at 120-150°C followed by mixing with binder, drying, and calcination. High-silica zeolite utilized is ZSM-5 zeolite, which is treated with aqueous ammonium solutions at equivalent ratio NH4 +:Na+ = (1.5-2.9):1.0 to degree of Na+ cation substitution above 99%.
EFFECT: increased catalytic activity and selectivity in benzene-ethylene alkylation process.
1 tbl, 7 ex
FIELD: hydrogenation-dehydrogenation catalysts.
SUBSTANCE: preparation of catalyst comprises depositing active components on γ-alumina carrier at stirring, carrier being preliminarily treated with concentrated NaOH solution. Active components are deposited consecutively in three steps. In the first step, preliminarily prepared chitosan in acetic acid solution with KCl solution is deposited for 60-65 min; in the second step, sodium tetrachloropaladate(II) trihydrate Na2PdCl4·3H2O solution is deposited for 60-65 min; and, in the third step, hydrazine hydrate solution as reducing agent is added for 180-240 min. After each step, resulting suspension is filtered off, washed, and dried at 293-303K for 1-2 h in vacuum. Catalyst can be used in chemical industry and in processing of industrial and household wastes.
EFFECT: enhanced nitrate hydrogenation efficiency.
6 cl, 1 dwg, 6 ex
FIELD: organic synthesis catalysts.
SUBSTANCE: invention relates to improved method of preparing double metal cyanide catalysts for synthesis of polyether-polyols via polyaddition alkylene oxides to starting compounds possessing active hydrogen atoms. Method comprises following steps: (i) mixing one or several solutions of water-soluble salts of Zn(II), Fe(II), Ni(II), Mn(II), Co(II), Sn(II), Pb(II), Fe(III), Mo(IV), Mo(VI), Al(III), V(V), V(IV), Sr(II), W(VI), Cu(II), or Cr(III) with solution of water-soluble cyanide ions-containing salt or acid of Fe(II), Fe(III), Co(II), Co(III), Cr(II), Cr(III), Mn(II), Mn(III), Ir(III), Ni(II), Rh(III), Ru(II), V(IV), or V(V) with the aid of mixing nozzle, preferably jet disperser; (ii) isolation of catalyst from resulting dispersion; (iii) washing; and (iv) drying.
EFFECT: increased catalytic activity, reduced particle size, and narrowed size distribution of particles in polyether-polyols production process.
8 cl, 5 dwg, 9 ex
FIELD: industrial organic synthesis and catalysts.
SUBSTANCE: invention provides catalyst for synthesis of thiophene from furan and hydrogen sulfide, which catalyst contains 3.1-4.2 wt %: boron oxide supported by alumina. Catalyst is prepared via mixing boron acid solution with aluminum hydroxide followed by extrusion and heat treatment, said aluminum hydroxide being aluminum hydroxide with pseudoboehmite structure or mixture thereof with aluminum hydroxide prepared via thermochemical activation process. Thiophene production process is accomplished via furan/hydrogen sulfide reaction in presence of above-described catalyst at 300-350 sulfate, hydrogen sulfide-to-furan molar ratio (6-11):1, and furan feed rate 3.7 to 11.1 mole/h per 1 g catalyst.
EFFECT: increased thiophene formation selectivity to 98-100%.
4 cl, 1 tbl, 7 ex
FIELD: chemical industry; methods of production of zirconium oxides
SUBSTANCE: the invention is pertaining to the field of chemical industry, in particular, to the methods of obtaining of zirconium oxide for production of the catalytic agents used, for example, in the reactions of the organic synthesis. The invention presents the method of obtaining of zirconium oxide for production of the catalytic agents, which includes the operations of dissolution of the zirconium salt in water, treatment of the solution with the alkaline reactant, settling of the metals hydroxides, filtration, separation of the mother-liquor from the settlings, the settlings water flushing, its drying, calcination and granulation and-or granulation by molding. At that dissolution of the source zirconium chloride and-or zirconium oxychloride is conducted in the sodium chloride solution with concentration of 200-250 g/dc3 till reaching of the concentration of zirconium of 20-120 g/dc3. Settling of zirconium oxyhydrate is conducted by the adding the initial chloride solution in the solution of the sodium hydroxide with concentration of 20-80 g/dm3 up to reaching the suspension pH equilibrium value - 5-8. Then the suspension is filtered up to the zirconium oxyhydrate pasta residual humidity of 40-80 %. The mother chloride solution is separated from the settlings of zirconium oxyhydrate and again use it for dissolution of the next batch of zirconium chloride and-or zirconium oxychloride. The settlings of zirconium oxyhydrate are subjected to drying at 80-100°C within 2-6 hours, then the dry settlings are suspended in the water at the ratio of liquid to solid L:S = (5-10 :1, the suspension is filtered, the sediment on the filter is flushed by water, the chlorides are wash off up to the residual concentration of ions of chlorine in the flush waters of 0.1-0.5 g/dm3, divided into 2 parts, one of which in amount of 60-80 % is subjected to drying and calcinations at the temperatures of 300-600°C, and other part in amount of 20-40 % is mixed with the calcined part of the settlings and subjected to granulation by extrusion at simultaneous heating and dehydration of the damp mixture of zirconium oxide and zirconium oxyhydrate with production of the target product. The technical result of the invention is improvement of quality of the produced zirconium oxide for production of the catalytic agents due to provision of the opportunity to use ZrO2 for the subsequent production of the various catalytic agents of the wide range of application and thereby improving the consumer properties of the produced production.
EFFECT: the invention ensures improvement of the quality of the produced zirconium oxide for production of the catalytic agents with improved consumer properties.
FIELD: technology for silicium dioxide production useful as additive for polymer reinforcement.
SUBSTANCE: claimed method includes silicate reaction with acidifying agent to produce silicium dioxide slurry separation and drying of said slurry, wherein reaction is carried out according to the next steps: i) providing base aqueous solution with pH from 2 to 5, preferably from 2.5 to 5; ii) simultaneous addition silicate and acidifying agent to said base solution maintaining solution pH from 2 to 5, preferably from 2.5 to 5; iii) addition silicate only without acidifying agent to produce pH from 7 to 10, preferably from 7.5 to 9.5; (iv) simultaneous addition silicate and acidifying agent to reaction medium to maintain pH from 7 to 10, preferably from 7.5 to 9.5; (v) addition acidifying agent only without silicate to produce reaction medium pH below 6. Obtained high structured silicium dioxides have the next characteristics: CTAB specific surface (SCTAB) is 40-525 m2/g; BET specific surface (SBET) is 45-550 m2/g; width Ld ((d84-d16)/d50) of particle size distribution measured by XDC grading analysis after ultrasound grinding is at least 0.92; and such pore distribution that V(d95-d50)/V(d5-d100) is at least 0.66.
EFFECT: improved material for polymer reinforcement.
FIELD: production of carbon carrier for catalysts.
SUBSTANCE: proposed method includes heating of moving layer of granulated furnace black used as backing, delivery of gaseous or vaporous hydrocarbons into soot layer followed by their thermal decomposition on soot surface forming layer of pyrocarbon at forming of layer of pyrocarbon and activation of material compacted by pyrocarbon at temperature of 800-900°C and unloading of finished product. Granulated furnace black at specific surface of 10-30 m2/g and adsorption rate of 95-115 ml/100 g is used as backing for compacting with pyrocarbon. Then, product is subjected to activation for obtaining total volume of pores of 0.2-1.7 cm3/g. Black is compacted by pyrocarbon at two stages: at first stage, granulated black is compacted to bulk density of 0.5-0.7 g/cm3, after which material is cooled down and screened at separation of fraction of granules of 1.6-3.5 mm; at second stage, this fraction is subjected to repeated pyrolytic compacting to bulk density of granules of 0.9-1.1 g/cm3.
EFFECT: enhanced economical efficiency; increased productivity of process.
FIELD: composite materials.
SUBSTANCE: invention relates to catalyst carriers and methods for preparation thereof. Novel porous composite material particles are proposed comprising alumina component and swelled clay component finely dispersed in alumina component in amount effective to raise hydrothermal stability, pore volume, and/or pore mode in the mesopore region in composite material particles as compared to swelled clay-free material. Also proposed are composite material particles and agglomerate particles obtained therefrom as well as a method for hydroprocessing of petroleum feedstock using agglomerates as hydroprocessing catalyst carrier.
EFFECT: increased hydrothermal stability and pore volume.
44 cl, 24 dwg, 19 tbl, 28 ex
FIELD: inorganic compounds technologies.
SUBSTANCE: invention provides porous composite particles containing alumina component and residue of at least one additional crystal growth inhibitor component dispersed within alumina component, wherein indicated composite particles have (A) specific surface area at least 80 m2/g; (B) average nitrogen-filled pore diameter 60 to 1000 Å; (C) total nitrogen-filled pore volume 0.2 to2.5 cm3/g and (D) average particle size 1 to 15 μm, and where, in indicated composite particles, (i) alumina component contains at least 70 wt % of crystalline boehmite with average crystallite size 20 to 200 Å, γ-alumina obtained from indicated crystalline boehmite, or mixture thereof; (ii) residue of additional is obtained from at least one ionic compound containing ammonium, alkali metal, alkali-earth metal cation, or mixtures thereof and wherein anion is selected from group comprising hydroxyl, silicate, phosphate, sulfate, or mixtures thereof and is present in composite particles in amounts between 0.5 and 10 % of the summary weight of alumina and additional components. Invention also provides a method to obtain composite particles, agglomerated particles prepared therefrom, and a method for hydroprocessing of petroleum feed using above-mentioned agglomerates.
EFFECT: avoided unnecessary calcination before addition of metals to increase average pore size and use of organic solvents for azeotropic removal of water.
36 cl, 2 tbl, 22 ex