Vanadium-titanium catalyst preparation method
FIELD: redox reaction catalysts.
SUBSTANCE: invention relates to methods for preparing vanadium-titanium oxide catalysts for redox reactions, e.g. for industrial processes of production of phthalic anhydride via oxidation of o-xylene, selective reduction nitrogen oxides, and detoxification of organochlorine compounds. Method of invention comprises following stages: providing titanyl sulfate solution; adding ammonia and then vanadium peroxide solution to titanyl sulfate solution or adding to the same vanadyl sulfate or oxalate and then ammonia solution; optionally ageing suspension resulting after mixing of solutions; filtration; and calcinations at 450°C.
EFFECT: increased heat resistance of active chlorobenzene oxidation catalyst and reduced catalyst preparation time (10-12 h instead 72 h as in a known method).
1 tbl, 3 ex
The invention relates to methods of producing vanadium oxide-titanium catalysts of oxidation-reduction reactions, such as industrial processes of production of phthalic anhydride by oxidation of o-xylene, selective reduction of nitrogen oxides and disposal of chlorinated organic compounds.
A method of obtaining vanadium-titanium catalyst for the oxidation of chlorobenzene with a molar ratio of V:Ti=10. The catalyst was prepared by mixing metavanadate ammonium (NH4VO3and suspension of titanium oxide in an aqueous solution of urea with the addition of oxalic acid to a pH equal to 4, further heating up to 90°C for 20 hours then the slurry is dried and calcined at 500°10 h (Moon S.W., Lee G-D., Park, S.S. and Hong S-S. "Catalytic combustion of chlorobenzene over V2O5/TiO2catalysts prepared by the precipitation-deposition method", J. React. Kinet. Catal. Lett., vol.82, No2, p.303-310,2004).
The disadvantage of this method is the low activity of the resulting catalyst in the oxidation of chlorobenzene, due, in particular, its low specific surface (9 m2/g). So, when the volumetric gas flow rate 15000 h-1conversion of chlorobenzene is 90% at 327°C.
A method of obtaining vanadium-titanium catalyst by adding titanium dioxide (anatase) in an aqueous solution of metavanadate ammonium (NH4VO ), bringing the pH of the slurry to 7.0, and 7.1 (addition of NH4OH or NHO3), stirring for 48 h and filtered. The resulting product is dried at 60°C for 24 h and calcined in air at 500°C for 2 hours Then the powder catalyst can be deposited on an inert substrate (ER 1145762, MKI B01J 23/22, 2001).
The disadvantage of this method is the low activity of the resulting catalyst in the oxidation of chlorobenzene, due, in particular, its low specific surface area (29 m2/g). Thus, when the concentration of chlorobenzene in air 9000-900 ppm and volumetric gas flow rate 20000 h-1conversion of chlorobenzene is only 39% at 450°and at lower concentrations of chlorobenzene, equal to 265 ppm, and a lower volumetric gas flow rate equal to 15000 h-1the conversion of chlorobenzene equal to 90% at 327°C. in Addition to the disadvantages of this method include its considerable duration (more than 3 days) and low thermal stability of the obtained catalyst. Thus, already at 500°in the composition of the catalyst is observed the appearance of rutile phase, which significantly reduces its activity.
Thus, the authors was to develop a method for production of vanadium-titanium catalyst, providing the high activity of the catalyst at low temperatures, more in the high thermal stability and reducing the process time of its receipt.
The problem is solved in the proposed method for production of vanadium-titanium catalyst, which includes obtaining the solution of titanyl sulfate, adding to the resulting solution of aqueous ammonia and then the peroxide solution of vanadium or adding to the resulting solution vanadyl sulfate or oxalate and then ammonia solution may extract the resulting suspension after mixing the solutions, the subsequent filtering and calcining at 450°C.
At the present time of patent and technical literature is not a method of obtaining vanadium-titanium catalyst, in which process the catalyst is lead from a solution mixture of the source compounds.
All known methods for producing a vanadium-titanium catalysts involve the interaction of solutions of salts of vanadium solid powder of titanium dioxide with subsequent filtering and calcining. The result is an oxide catalyst, where the vanadium oxide deposited on the surface of titanium dioxide. The principal difference of the proposed method against known is the process in mixture solutions using deposition of ammonia. The result is the catalyst structure of anatase, which is embedded ions of vanadium.
The proposed method can be implemented as follows. Get solution of titanyl Sul the veil in the water, add with stirring an aqueous solution of ammonia and hydrogen peroxide solution of vanadium. The resulting suspension heated at 60-80°C for 1-2 h In the case of use as the source of a mixture of a mixture of solutions of titanyl sulfate and vanadyl sulfate or oxalate in water to the mixture an aqueous solution of ammonia. Formed in the first and second cases, the precipitate is filtered off, slowly heated to 450±5°C and maintained at this temperature for 10h. Then cooled to room temperature. The resulting product certificate of x-ray phase analysis. Specific surface area determined by the method of "BET" on the analyzer TriStar 3000 V6.03A.
The resulting catalyst was tested in the oxidation of chlorobenzene in a flow reactor and the temperature range 300-350°C. was charged To the reactor, 0.5 g of catalyst in powder form with a particle size less than 0.25 mm in a mixture of four volumes of silicon carbide with a particle size also less than 0.25 mm At a temperature of 300-350°in the reactor serves a vapor mixture of chlorobenzene with air (concentration of chlorobenzene in a mixture 9000-900 ppm) with a bulk velocity of 20000 h-1. In gases after the reactor determine the unreacted chlorobenzene by adsorption him on silica gel (particle size 0.25-0.5 mm), elution its acetone and chromatography was carried out with an internal standard of durene. Transformed the E. of chlorobenzene in the products of complete combustion (CO 2) is determined by the gravimetric method (absorption Astarita). The results are given in the table.
|The composition of the catalyst||The concentration of chlorobenzene, ppm||Process temperature, °||Conversion of chlorobenzene, %||The output of the products of complete oxidation (CO2), %|
According to x-ray analysis of the catalyst obtained by the proposed method, more thermally stable than known since the appearance of rutile phase is observed at 600°C.
The proposed method is illustrated by the following examples.
Example 1. Dissolve of 7.36 g TiOSO4·2H2About 200 ml of water; add with stirring to 5.9 ml vodno the ammonia solution with a content of 24% NH 3and the peroxide solution of 0.34 g V2About5in 30 ml of water. The resulting suspension is heated at 60°C for 2 hours. The precipitate is filtered off, slowly heated to 450°C and maintained at this temperature for 10 hours. After cooling to room temperature receive oxide vanadium-titanium catalyst with a molar ratio of V:Ti=1:10 with the structure of anatase and specific surface 92 m2/year
Example 2. In a solution with a concentration of 41,11 g/l TiOSO4and 4.19 g/l VOSO4add with constant stirring an aqueous solution of ammonia with 24% of NH3upon reaching pH=8. The precipitate is filtered off, slowly heated to 450°C and maintained at this temperature for 10 hours. After cooling to room temperature receive oxide vanadium-titanium catalyst with a molar ratio of V:Ti=1:10 with the structure of anatase and specific surface 66 m2/year
Example 3. In a solution with a concentration of 41,11 g/l TiOSO4and 3,984 g/l VOC2O4add with constant stirring an aqueous solution of ammonia with 24% of NH3upon reaching pH=8. The precipitate is filtered off, slowly heated to 450°C and maintained at this temperature for 10 hours. After cooling to room temperature receive oxide vanadium-titanium catalyst with a molar ratio of V:Ti=1:10 astructural of anatase and specific surface 76 m 2/year
Thus, the proposed method allows to obtain a heat-resistant catalyst of the oxidation of chlorobenzene with high catalytic activity. In addition, significantly reduced the duration of the process of preparation of the catalyst (10-12 hours versus 72 hours in a known way).
A method for production of vanadium-titanium catalyst, characterized in that it comprises the production of a solution of titanyl sulfate, adding to the resulting solution of aqueous ammonia and then the peroxide solution of vanadium or adding to the resulting solution vanadyl sulfate or oxalate and then ammonia solution may extract the resulting suspension after mixing the solutions, the subsequent filtering and calcining at 450°C.
FIELD: production of catalytic compositions.
SUBSTANCE: proposed method includes combining and bringing into interaction at least one component of non-precious metal of group VII and at least two components of metal of VIB group in presence of proton liquid; then composition thus obtained is separated and is dried; total amount of components of metals of group VIII and group VIB in terms of oxides is at least 50 mass-% of catalytic composition in dry mass. Molar ratio of metals of group VIB to non-precious metals of group VIII ranges from 10:1 to 1:10. Organic oxygen-containing additive is introduced before, during or after combining and bringing components into interaction; this additive contains at least one atom of carbon, one atom of hydrogen and one atom of oxygen in such amount that ratio of total amount of introduced additive to total amount of components of metals of group VIII to group VIB should be no less than 0.01. This method includes also hydraulic treatment of hydrocarbon material in presence of said catalytic composition.
EFFECT: enhanced efficiency.
29 cl, 8 ex
FIELD: chemical industry; materials and the methods for the catalyst carrier manufacture.
SUBSTANCE: the invention is pertaining to the new mixed oxides produced from ceric oxide and zirconium oxide, which can used as the catalyzers or the catalyzers carriers for purification of the combustion engine exhaust gases. The mixed oxide possesses the polyphase cubical form of the crystallization and oxygenous capacity of at least 260/ micromoles of O2 /g of the sample and the speed of the oxygen extraction of more than 1.0 mg-O2/m2-minute, which are measured after combustion within 4 hours at the temperature of 1000°C. The invention also presents the substrate with the cover containing the indicated mixed oxide. The method of production of the polycrystallic particles of the indicated mixed ceric-zirconium oxide includes the following stages: i) production of the solution of the mixed salt which are containing, at least, one salt of cerium and, at least, one salt of zirconium in the concentration, sufficient for formation of the polycrystallic particles of the corresponding dry product on the basis of the mixed oxide. At that the indicated particles have the cerium-oxide component and zirconium-oxide component, in which these components are distributed inside the subcrystalline structure of the particles in such a manner, that each crystallite in the particle consists of a set of the adjacent one to another domains, in which the atomic ratios of Ce:Zr which are inherited by the adjacent to each other domains, are characterized by the degree of the non-uniformity with respect to each other and determined by means of the method of the X-ray dissipation the small angles and expressed by the normalized intensity of the dissipation I(Q) within the limits from approximately 47 up to approximately 119 at vector of dissipation Q, equal to 0.10 A-1; ii) treatment of the solution of the mixed salt produced in compliance with the stage (i),with the help of the base with formation of sediment; iii) treatment of the sediment produced in compliance with the stage (ii),using the oxidative agent in amount, sufficient for oxidizing Ce+3 up to Ce+4; iv) washing and drying of the residue produced in compliance with the stage (iii); and v) calcination of the dry sediment produced in compliance with the stage (iv),as the result there are produced polycrystallic particles of the oxide of ceric and zirconium in the form of the mixed oxide with the above indicated characteristics. The technical result is the produced mixed oxide possesses both the high oxygenous capacitance, and the heightened speed of the oxygen return in the conditions of the high temperatures.
EFFECT: the invention ensures production of the mixed oxide manufactured from ceric oxide and zirconium oxide and possessing the high oxygenous capacitance and the heightened speed of the oxygen return in the conditions of the high temperatures.
68 cl, 21 ex, 2 dwg
FIELD: catalyst preparation methods.
SUBSTANCE: invention provides Fischer-Tropsch catalyst, which consists essentially of cobalt oxide deposited on inert carrier essentially composed of alumina, said cobalt oxide being consisted essentially of crystals with average particle size between 20 and 80 Å. Catalyst preparation procedure comprises following stages: (i) preparing alumina-supported intermediate compound having general formula I: [Co2+ 1-xAl+3 x(OH)2]x+[An- x/n]·mH2O (I), wherein x ranges from 0.2 to 0.4, preferably from 0.25 to 0.35; A represents anion; x/n number of anions required to neutralize positive charge; and m ranges from 0 to 6 and preferably is equal to 4; (ii) calcining intermediate compound I to form crystalline cobalt oxide. Invention also described a Fischer-Tropsch process for production of paraffin hydrocarbons in presence of above-defined catalyst.
EFFECT: optimized catalyst composition.
16 cl, 12 tbl, 2 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: catalyst preparation methods.
SUBSTANCE: invention, in particular, relates to catalyst based on synthetic mesoporous crystalline materials and provides hydrocarbon conversion catalyst composed of: group VIII metal/SO4 2-/ZrO2-EOx, where E represents element of the group III or IV of Mendeleev's periodic table, x = 1.5 or 2, content of SO4 2- is 0.1 to 10% by weight, ZrO2/EOx molar ratio is 1:(0.1-1.0), which has porous crystalline structure with specific surface 300-800 m2/g and summary pore volume 0.3-0.8 cm3/g. Preparation method comprises precipitation of zirconium compounds, in particular zirconium hydroxide or zirconyl, under hydrothermal conditions in presence of surfactant to form mesoporous phase, which is stabilized with stabilizing agents: group III and IV elements. When stabilization is achieved, if necessary, acidity is adjusted and group VIII metal is added.
EFFECT: increased specific surface area and heat resistance at simplified technology.
9 cl, 2 dwg, 2 tbl, 6 ex
FIELD: catalyst preparation methods.
SUBSTANCE: invention relates to methods for preparing carbon monoxide-conversion catalysts used in production of hydrogen, nitrogen-hydrogen mixture, and other hydrogen-containing gases. According to first option, active catalyst component, i.e. iron compound, is precipitated from solution with precipitation reagent, whereupon precipitate is separated from mother liquor and washed to form catalyst mass, which is molded and subjected to heat treatment, re-washed, mixed with chromic anhydride and subjected to final heat treatment: at 280-420°C after molding or at 50-200°C before molding of catalyst mass. According to second option, iron compound is first mixed with promoting additives and cations of promoting additives are precipitated jointly with iron cations, resulting precipitate is separated from mother liquor, washed and subjected to heat treatment, re-washed, mixed with chromic anhydride and subjected to final heat treatment: at 280-420°C after molding or at 50-200°C before molding of catalyst mass. As iron compound in the first and second options, ferrous and ferric sulfates and, as precipitation reagent, carbonate salts or corresponding hydroxides are utilized. Promoting additives are selected from Cu, Mn, and Al or, in the second option, their mixture.
EFFECT: reduced content of sulfur in finished catalyst at the same catalyst activity.
3 cl, 1 tbl, 12 ex
FIELD: industrial organic synthesis catalysts.
SUBSTANCE: invention relates to environmentally friendly processes for production of isoalkanes via gas-phase skeletal isomerization of linear alkanes in presence of catalyst. Invention provides catalyst for production of hexane isomers through skeletal isomerization of n-hexane, which catalyst contains sulfurized zirconium-aluminum dioxide supplemented by platinum and has concentration of Lewis acid sites on its surface 220-250 μmole/g. Catalyst is prepared by precipitation of combined zirconium-aluminum hydroxide from zirconium and aluminum nitrates followed by deposition of sulfate and calcination in air flow before further treatment with platinum salts. Hexane isomer production process in presence of above-defined cat is also described.
EFFECT: increased catalyst activity.
5 cl, 2 tbl, 6 ex
FIELD: hydrogenation-dehydrogenation catalysts.
SUBSTANCE: palladium-containing hydrogenation catalyst, which can be used to control rate of autocatalytic hydrogenation reactions, is prepared by hydrogen-mediated reduction of bivalent palladium from starting compound into zero-valence palladium and precipitation of reduced zero-valence palladium on carbon material, wherein said starting material is tetraaqua-palladium(II) perchlorate and said carbon material is nano-cluster carbon black. Reduction of palladium from starting compound and precipitation of zero-valence palladium on carbon material are accomplished by separate portions.
EFFECT: increased catalytic activity, enabled catalyst preparation under milder conditions, and reduced preparation cost.
1 dwg, 1 tbl, 12 ex
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: 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: oxidation catalysts.
SUBSTANCE: SO2-into-SO3 conversion catalyst contains following active components: vanadium oxide, alkali metal (K, Na, Rb, Contains) oxides, sulfur oxides, and silica framework formed from natural and/or synthetic silica and having pores with radii up to 65000 , among which fraction of pores with radii larger 10000 does not exceed 50%, while content of sulfuric acid-insoluble vanadium compounds (on conversion to V2O5) does not exceed 4.0% by weight. Fraction of pores with radii 1000-10000 does not exceed 35% and that less than 75 at most 9%.
EFFECT: improved performance characteristics of catalyst operated in reactor zones at medium and maximum temperature due to under conditions activity at 420-530оС.
3 cl, 1 tbl, 8 ex
FIELD: inorganic synthesis catalysts.
SUBSTANCE: decomposition if N2O under Ostwald process conditions at 750-1000°C and pressure 0.9-15 bar is conducted on catalyst, which comprises (A) support composed of α-Al2O3, ZrO2, SeO2, or mixture thereof and (B) supported coating composed of rhodium or rhodium oxide, or mixed Pd-Rh catalyst. Apparatus wherein N2O is decomposed under Ostwald process conditions on the above-defined catalyst is also described. Catalyst is disposed successively downstream of catalyst grids in direction of stream of NH3 to be oxidized.
EFFECT: increased catalyst activity.
8 cl, 2 tbl, 3 ex