The method of preparation of the catalyst based on cobalt oxide (ii)
(57) Abstract:The method of producing catalyst based on cobalt (2) exercise by mixing powders of electrolytic cobalt and urea content of the urea in a mixture of 20 to 30 wt.%. The resulting mixture tabletirujut under pressure, after which the tablets after their discharge aluminum oxide calcined in air at 910 - 1150°C to remove the urea, then after separation of the alumina pills again calcined at 1100 - 1200°C. Calcined as indicated tablets cooled, impregnated with a calcium salt solution and again calcined at 300 to 800°C. table 1. The invention relates to oxide type catalysts obtained on the basis of cobalt oxide, and can be used for oxidation of carbon monoxide.Of analogues known method of preparation of the catalyst based on oxides: cobalt (III), manganese (IV), copper (II) and silver (hopcalite catalyst) specified in the chemical encyclopedia (volume I, M.: Soviet encyclopedia, 1961, S. 987).The method is carried out by mixing aqueous suspensions of these oxides with subsequent filtering, drying, pressing the obtained solid phase and crushing the obtained compacts the grain of certain razmutie L. Hofer J). and others in the journal "ICatalysis" [J. Catal. , 1964, 3, 5, 451]. The method is carried out by deposition of cobalt nitrate solution of potassium carbonate at 80aboutWith subsequent drying and calcining at 700aboutWith the obtained precipitate.The disadvantage of the methods is the low strength of the resulting catalysts.You know the more stable catalyst of cobalt oxide (II) aluminum oxide, referred to in the description of the patent France [FR. Pat., class. In 01, 1318764, 14, 1963].The specified catalyst was prepared by impregnating pellets of aluminum oxide with a solution of cobalt nitrate, followed by drying and calcining the pellets at 550aboutC.However, obtained at the specified way catalyst reduces its activity due to the formation of catalytically inactive cobalt aluminate.The closest in technical essence to the claimed method is a method of obtaining a catalyst of cobalt oxide (II), magnesium oxide, described in the French patent is U.S. Pat. 1318764, Appl. 11.01.62, publ. 14.01.63.The way the prototype includes the melting of magnesium oxide in an electric furnace; cooling the melt to a solid phase; dispersing the obtained melt to the size of the cha is the mixture with water; molding the mixture obtained under item 5 in the form of granules; drying the granules; calcining the granules at a temperature of 1500aboutC; impregnating the granules with a solution of nitrate of cobalt; drying the impregnated granules; calcining the dried pellets at a temperature of 550aboutC.The catalyst obtained by the prototype contains cobalt oxide (II) 5% , of magnesium oxide - 95%, stable at 800aboutWith, abrasion resistant, has a surface - 0.2 m2/g, a porosity of 60%.The disadvantage of the prototype is the low content of the active component - cobalt oxide (II).The technical essence of the claimed method consists in the fact that a catalyst based on cobalt oxide includes the following stages mixing powders of electrolytic cobalt and urea content of the urea in a mixture of 20-30 wt. % ; molding the obtained powder mixture under pressure; a glowing molded pellets in air at a temperature of 910-1150aboutWith mixed with aluminum oxide to remove urea; the calcination calcined granules at 1100-1200aboutWithout access of air within 20-60 min; impregnation of calcined granules of a calcium salt solution; drying the impregnated granules, calcining the dried granules to complete dissolution of salt calove oxide cobalt (II) oxide content of cobalt (II) not less than 20% and with high performance.The table below shows comparative data of the prototype and the proposed method.As can be seen from the table, the proposed method is compared with the prototype allows to increase the content of the active component is not less than 4 times, while maintaining high operational characteristics: thermal stability and abrasion resistance.The claimed method is as follows.1. Prepare a mixture containing 0.76 kg of electrolytic cobalt and 0.24 kg of urea.2. The resulting mixture was molded in the form of cylindrical tablets having a height and a diameter of 5 mm, under pressure 900-1000 .3. Received under item (2 tablets mixed with a granular aluminum oxide in a ratio of 1:1 by weight.4. Received on p. 3 the mixture is calcined in air at 950 25aboutTo complete burnout of urea.5. From calcined under item 4 mixture by sifting delete previously entered in the granules of aluminum oxide.6. Remaining after screening on p. 5 tablets calcined at 1150aboutWith without air for 30 minutes7. Calcined under item 6 tablets impregnated with a 17% solution of calcium nitrate.8. Propitanni is="ptx2">The result is a catalyst with the following characteristics: Specific surface area of 1 m2/g bulk density of 1.9 g/cm3The porosity of 62% Mechanical tensile strength abrasion 97% of the Content in the catalyst of cobalt oxide (II) 29% of the Content in the catalyst of cobalt metal 68% of the Content in the catalyst compounds of calcium 3% of the Activity of the catalyst is the temperature of half-transformation of carbon monoxide on the catalyst in the oxidation of carbon monoxide 178aboutWith the Activity defined in the facility and under the conditions described Belov, A. A., and others in the journal "Theory. and experimental. chemistry, 1991, T. 27, No. 5, S. 591. The METHOD of preparation of the CATALYST BASED ON COBALT OXIDE (II), comprising mixing powdered components, granulating the mixture, calcining the granules and their impregnation with a salt solution followed by heat treatment to decompose the salt and obtain the target product, wherein the mixture is subjected to electrolytic cobalt and urea content of the urea in a mixture of 20 to 30 wt.%, the resulting mixture tabletirujut under pressure, then tablets lace alumina and calcined in air at 910 - 1150oTo complete removal of urea, after which the tab is promote to room temperature and impregnated with a solution of calcium salts followed by calcination at 330 - 800oC.
FIELD: chemical industry.
SUBSTANCE: the invention is pertinent to the field of chemical industry, in particular to production of a catalysts and processes of oxidation of ammonia in production of a weak nitric acid. The invention offers an ammonia conversion catalyst on the basis of the mixture of oxides of unitized structure and a method oxidation of ammonia in production of weak nitric acid. The catalyst represents a mixture of oxides of the over-all formula (AxByO3Z)k (MmOn)f, (NwPgvOv)r where: A - cation of Ca, Sr, Ba, Mg, Be, Ln or their mixtures; B - cations of Mn, Fe, Ni, Co, Cr, Cu, V, A1 or their mixtures; x=0-2, y=1-2, z=0.8-l.7; M - A1, Si, Zr, Cr, Ln, Mn, Fe, Co, Cu, V, Ca, Sr, Ba, Mg, Be or their mixtures; m=l-3, n=l-2; N - Ti, Al, Si, Zr, Ca, Mg, Ln, W, Mo or their mixtures, P - phosphorus, O - oxygen; w=0-2, g=0-2, v=l-3; k, f and r - mass %, at a ratio (k+f)/r=0-l, f/r=0-l, k/f = 0-100. The catalyst is intended for use in a composition of a two-stage catalytic system generated by different methods, also in a set with the trapping platinoid screens and-or inert nozzles. The technical result ensures activity, selectivity and stability of the catalyst to thermocycles at its use in two-stage catalytic system with a decreased loading of platinoid screens.
EFFECT: the invention ensures high activity, selectivity and stability of the catalyst to thermocycles at its use in two-stage catalytic system with a decreased loading of platinoid screens.
8 cl, 1 tbl, 5 ex
FIELD: catalyst manufacture technology.
SUBSTANCE: invention relates to carbon monoxide-water steam conversion to form nitrogen-hydrogen mixture that can be used in ammonia synthesis. Preparation of catalyst comprises precipitation of iron hydroxide from iron nitrate solution with ammonia-containing precipitator, washing of iron hydroxide to remove nitrate ions, mixing with copper compound, granulation, and drying and calcination of granules. Invention is characterized by that iron hydroxide is mixed with copper and calcium oxides at molar ratio Fe2O3/CuO/CaO = 1:(0.03-0.2):(1.0-2.0), after which mechanical activation is performed. Resulting catalyst is 1.8-2.0-fold stronger and by 11.0-15.4% more active than prototype catalyst.
EFFECT: increased strength and catalytic activity.
1 tbl, 3 ex
FIELD: nitric acid production.
SUBSTANCE: invention relates to decomposition of N2O from nitric acid production emission gases. N2O is decomposed by contacting N2O-containing emission gas escaping absorption column with catalyst containing at least one cobalt oxide compound and at least one magnesium oxide compound under conditions favoring formation of N2O into nitrogen and oxygen gases, content of said cobalt oxide compounds ranging between 0.1 and 50% and that of magnesium oxide compounds between 50 and 99.9% based on the total weight of catalyst. At least 30% of cobalt in catalyst are in trivalent state. Preparation of catalyst envisages dry mixing of cobalt oxide and magnesium oxide compounds or corresponding precursors followed by compaction of the mixture under anhydrous conditions such that resulting catalyst has desired volume density.
EFFECT: enabled high degree of N2O decomposition at low temperatures and without disadvantages for nitric acid production process.
20 cl, 2 dwg
FIELD: petrochemical process catalysts.
SUBSTANCE: invention is dealing with catalyst applicable in saturated hydrocarbon ammoxidation process resulting in corresponding unsaturated nitrile. Catalyst composition of invention comprises complex of catalytic oxides of iron, bismuth, molybdenum, cobalt, cerium, antimony, at least one of nickel and magnesium, and at least one of lithium, sodium, potassium, rubidium, and thallium and is described by following empirical formula: AaBbCcFedBieCofCegSbhMomOx, wherein A represents at least one of Cr, P, Sn, Te, B, Ge, Zn, In, Mn, Ca, W, and mixtures thereof; B represents at least one of Li, Na, K, Rb, Cs, Ti, and mixtures thereof; C represents at least one of Ni, Mg, and mixtures thereof; a varies from 0 to 4.0, b from 0.01 to 1.5, c from 1.0 to 10.0, d from 0.1 to 5.0, e from 0.1 to 2.0, f from 0.1 to 10.0, g from 0.1 to 2.0, h from 0.1 to 2.0, m from 12.0 to 18.0, and m is a number determined by requirements of valences of other elements present. Ammoxidation processes for propylene, ethylene, or their mixtures to produce, respectively, acrylonitrile, methacrylonitrile, or their mixtures in presence of above-defined catalytic composition is likewise described.
EFFECT: increased olefin conversion.
9 cl, 1 tbl
FIELD: inorganic synthesis catalysts.
SUBSTANCE: passivation of ammonia synthesis catalyst is accomplished via consecutively treating reduced iron catalyst with oxidant at elevated temperatures and process flow rates. Treatment of catalyst with oxidant is commenced with water steam or steam/nitrogen mixture at 150-300°C while further elevating temperature by 50-200°C, after which temperature is lowered to 150-300°C, at which temperature water steam or steam/nitrogen mixture is supplemented by air and treatment of catalyst is continued with resulting mixture while elevating temperature by 50-200°C followed by reduction of catalyst temperature in this mixture to 150-300°C and cooling of catalyst with nitrogen/oxygen mixture at initial ratio not higher than 1:0.1 to temperature 30°C and lower until nitrogen/oxygen mixture gradually achieves pure air composition.
EFFECT: prevented self-inflammation of ammonia synthesis catalyst when being discharged from synthesis towers due to more full oxidation.
6 cl, 1 tbl, 5 ex
FIELD: industrial organic synthesis and petrochemistry.
SUBSTANCE: isoamylenes are subjected to dehydrogenation in presence of overheated water steam and catalyst containing, wt %: potassium oxide and/or lithium oxide, and/or rubidium oxide, and/or cesium oxide, 10-40; cerium(IV) oxide 2-20; magnesium oxide 2-10; calcium carbonate 2-10; sulfur 0.2-5; and ferric oxide - the rest.
EFFECT: increased isoamylene dehydrogenation degree due to increased catalyst selectivity with regard to isoprene and prolonged service time of catalyst.
2 tbl, 22 ex
FIELD: synthesis gas generation catalysts.
SUBSTANCE: invention provides catalyst for steam generation of synthesis gas containing 2.2-8.2% nickel oxide and 3.0-6.5% magnesium oxide deposited on heat-resistant porous metallic carrier having specific surface area 0.10-0.15 m2/g, summary pore volume 0.09-0.12 cm3/g, predominant pore radius 2-20 μm, and porosity 40-60%. Synthesis gas is obtained by steam-mediated conversion of hydrocarbons at 450-850°C.
EFFECT: increased heat conductivity of catalyst and catalytic activity.
11 cl, 1 tbl, 8 ex
FIELD: industrial inorganic synthesis and catalysts.
SUBSTANCE: invention provides ammonia synthesis catalyst containing VII group and group VIB metal compound nitrides. Ammonia is produced from ammonia synthesis gas by bringing the latter into contact with proposed catalyst under conditions favoring formation of ammonia.
EFFECT: increased ammonia synthesis productivity.
8 cl, 2 tbl, 19 ex
FIELD: chemical industry; catalyzers for dehydrogenation of the alkyl-aromatic hydrocarbons.
SUBSTANCE: the invention presents the catalyzer used for dehydrogenation the alkyl-aromatic hydrocarbons of the following composition (in mass%): potassium compounds (in terms of potassium oxide) - 8.0-25.0; magnesium compounds and-or calcium compounds (in terms of magnesium oxide and-or calcium oxide) - 0.2-7.0; molybdenum oxide - 0.7-7.0; cerium oxide - 1.0-15.0; Portland cement - 0.5-12.0; lanthanum oxide and-or neodymium oxide - 0.01-7.0; iron oxide - the rest. The technical result of the invention is the increase of activity, selectivity of the catalyzer, as well as the thermal stability, which increases the catalyzer service life.
EFFECT: the invention ensures the increase of activity, selectivity, thermal stability and the service life of the catalyzer.
4 cl, 20 ex, 2 tbl, 2 dwg