The method of preparation of the catalyst for conversion of hydrocarbons
(57) Abstract:
Describes the method of preparation of the catalyst for conversion of hydrocarbons, including the preparation of a carrier by mixing alumina, aluminum hydroxide, technical calcium aluminate, the introduction of aqueous plasticizing burnable additives, molding, the crop has wilted in the air, the heat carrier in an environment of steam at a pressure of 1 to 2 ATM and a temperature of 150 - 170oC, the subsequent drying with the rise of temperature in the drying zone at a speed of 40 - 60oC per hour up to 120oC and exposure media at this temperature, calcining the carrier 1450 - 1500oC, the subsequent impregnation of the support with solutions of nitrates of Nickel and aluminum, drying and heat treatment of the catalyst mass, in this case, before forming the reaction mass was kept for 10 - 60 min and shaping is done with a rotary granulator at a relative humidity of mass 20 to 30%, the pressure molding 20 - 40 ATM and the number of revolutions of the rotor 5 to 20 rpm Technical result is an increase of catalytic activity. The invention relates to the production of catalysts for conversion of hydrocarbons, in particular, for process steam, steam-air and propakistani conversionsentence acids, and can be used in chemical, petrochemical and other industries.There is a method of preparation of the catalyst for conversion of hydrocarbons, including the preparation of a carrier by mixing alumina, aluminum hydroxide, technical aluminate calcium, graphite, introducing aqueous plasticizing additive is polyvinyl alcohol, molding, wilting media on the air, the heat treatment in the environment of water vapor or steam condensate at 85-95oC for 2 to 4 hours, high temperature calcination of the carrier at 1450 - 1550oC, the carrier impregnated with solutions of nitrates of Nickel and aluminum, followed by drying and calcination of the catalyst mass [SU 1780208 A1, op. 10.11.95].Also known preparation method of catalyst for steam reforming of hydrocarbons by impregnation with a solution of Nickel salts media containing aluminum oxide and from 0.5 to 25 wt.%. of calcium oxide, at least part of the calcium oxide is associated with the aluminum oxide in the form of so-called callionymidae cement, which consists of calcium oxide in the form of aluminates CaO6Al2O3and CaO2Al2O3followed by drying, calcination [DE 19720599 A1, class effect is achieved is a method of preparation of the catalyst for conversion of hydrocarbons including the preparation of a carrier by mixing alumina, aluminum hydroxide, technical calcium aluminate, the introduction of aqueous plasticizing burnable additives, molding, the crop has wilted media on the air, its heat treatment in an environment of steam at a pressure of 1-2 ATM and a temperature of 150-170oC, followed by drying with high temperature in the drying zone with a speed of 40-60oC per hour up to 120oC and exposure media at this temperature for 1.5-2 h, the high-temperature calcination of the carrier at a temperature of 1450 - 1550oC, the subsequent impregnation of the support with solutions of nitrates of Nickel and aluminum, followed by drying and heat treatment of the catalyst mass [EN, 2143319 C1, publ. 27.12.99].The present invention is to obtain a catalyst with increased activity.To solve the problem proposed by the present method of preparation of the catalyst for conversion of hydrocarbons, including the preparation of a carrier by mixing alumina, aluminum hydroxide, technical calcium aluminate, the introduction of aqueous plasticizing burnable additives, forming a rotary granulator at a relative humidity of mass 20 to 30%, the pressure Formosan minutes the crop has wilted in the air, the heat media in the environment of water vapor or aqueous medium at a temperature of 90 - 100oC at a pressure of 1 to 2 ATM and a temperature of 150 - 170oC, followed by drying with high temperature in the drying zone with a speed of 40 to 60oC per hour up to 120oC and exposure media at this temperature for 1.5-2.0 hours, calcining the carrier 1450 - 1500oC, the subsequent impregnation of the support with solutions of nitrates of Nickel and aluminum, drying and heat treatment of the catalyst mass.Carrying out molding at a rotary granulator at a relative humidity of mass 20 to 30%, the pressure molding 20 - 40 ATM and the number of revolutions of the rotor 5 to 20 rpm provides a carrier in the form of granules with one or more holes, the external and internal surfaces which have the shape of a truncated cone.The catalyst based on the media in comparison with the known has a more developed porosity and, as a consequence, increased catalytic activity.The following examples illustrate the present invention.Example.Nickel-containing catalyst for the conversion of hydrocarbons obtained by impregnation of the carrier with an aqueous solution of Nickel nitrate is found in the following amount: ground alumina 4.2 kg, the aluminum hydroxide - 6.5 kg, technical aluminate calcium - 4.5 kg, put them in a Z-shaped mixer and stirred for 30 minutes. The resulting mixture is moistened with an aqueous solution of polyvinyl alcohol, maintain the reaction mass at 40 minutes and molded at a relative humidity of mass 20 to 30%, the pressure molding 20 - 40 ATM and the number of revolutions of the rotor 5 to 20 rpm in the form of annular pellets, the external and internal surfaces which have the shape of a truncated cone. Granules provalivajut on the air for about a day, spend hydrothermal processing of media in the autoclave in an environment of water vapor pressure of 1.5 ATM, a temperature of 160oC for 1.5 hours. The drying medium is carried out in a shaft of electric furnaces in the following mode: the temperature raising speed of 50oC to 120oC and at this temperature, the carrier can withstand 1.7 hours. The dried carrier is calcined in a tunnel kiln at a temperature of 1450oC, where due to the processes of sintering is formed physical structure of the media.To obtain the catalyst of a given amount of Nickel oxide (11% wt. ) calcined and cooled medium is subjected to 3-fold impregnation in the scrubber with a solution of nitrate salts of Nickel and aluminum is after each impregnation to decompose the nitrates.From the obtained catalyst batch adwareaway a sample volume of 100 ml. Ring crush and scatter to obtain fractions of 2-3 mm, in a quartz reactor download 5 cm3catalyst, carried out the conversion of natural gas under the following conditions:- volumetric steam:gas ratio = 2.1:1;
- the volumetric rate of 6000 h-1;
temperature 700oC.The residual fraction of methane in dry converted gas is 3.5%
When tested in the same conditions of the catalyst, obtained in a known manner, the residual fraction of methane amounted to 4.0%.According to the invention increase the activity of the catalyst for conversion of hydrocarbons is due to the fact that the porosity of the thus obtained catalyst is 50 - 65%, while the porosity of the known catalyst is 35%, increase in porosity reduces the influence of interdiffuse braking reaction of methane conversion and, thus, increases the effective rate constant of reaction on the catalyst. The preparation method of catalyst for the conversion of hydrocarbons comprising preparing a carrier by mixing alumina, aluminum hydroxide, technical aluminate calcium, suggesting the media in an environment of steam at a pressure of 1 - 2 ATM and a temperature of 150 - 170oC, the subsequent drying with the rise of temperature in the drying zone at a speed of 40 - 60oC per hour up to 120oC and exposure media at this temperature, calcining the carrier 1450 - 1500oC, the subsequent impregnation of the support with solutions of nitrates of Nickel and aluminum, drying and heat treatment of the catalyst mass, characterized in that before forming the reaction mass was kept for 10 - 60 min and shaping is done with a rotary granulator at a relative humidity of mass 20 to 30%, the pressure molding 20 - 40 ATM and the number of revolutions of the rotor 5 to 20 rpm
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