RU2527259C2 - Catalyst of obtaining element sulphur in claus process, method of its preparation and method of carrying out claus process - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to catalysts, used for obtaining element sulphur in Claus process. Claimed catalyst of obtaining element sulphur in Claus process represents mixture χ-, γ-Al₂O₃ and X-ray amorphous phase of aluminium oxide in the following ratio: χ-Al₂O₃ and X-ray amorphous phase 65-99.9 wt % and γ-Al₂O₃ 0.1-35, wt %. Volume of mesopores with diameter from 3 to 10 nm in catalyst constitutes 0.12-0.35 cm³/g, and ratio of volume of mesopores with diameter 3-10 nm to volume of ultramacropores with diameter more than 1000 nm is less than or equals 5. Invention also relates to method of preparing said catalyst and method of carrying out Claus process with its application.

EFFECT: application of claimed catalyst makes it possible to increase efficiency of Claus process.

11 cl, 1 dwg, 4 tbl, 12 ex

Description

The invention relates to environmentally friendly methods for producing granular spherical alumina catalyst used to produce elemental sulfur from sulfur-containing gases by the Claus process, as well as to a method for carrying out the Claus process.

The processing of gases containing sulfur compounds by the Klaus process involves two stages.

In the first thermal stage, a gas containing hydrogen sulfide or sulfur dioxide is treated at a temperature of 950-1350 ° C so that the ratio of H ₂ S / SO ₂ in the gas mixture entering the second stage is 2.

When processing hydrogen sulfide-containing gases, oil and gas purification 1/3 H ₂ S is oxidized to SO ₂ by the reaction:

H ₂ S + 3/2 O ₂ → SO ₂ + H ₂ O.

When processing waste gases from metallurgical plants containing sulfur dioxide, 2/3 SO _{2 is} reduced to H ₂ S in the presence of a controlled amount of methane or synthesis gas.

The sulfur recovery after the thermal stage is 65-70% for hydrogen sulfide-containing gases and 50-55% for gases containing sulfur dioxide.

In the second catalytic stage, H ₂ S interacts with SO ₂ to form sulfur by the Claus reaction:

2H ₂ S + SO ₂ ↔ 3 / n S _n + 2H ₂ O.

Klaus reaction is reversible. As a result of this, the technologically catalytic stage of the process is carried out in two or three successive converters, each of which contains a catalyst layer, with a decrease in temperature from the first converter to the last. After each converter, the reaction gases are cooled to a sulfur condensation temperature, the sulfur formed is separated, and the gas stream after heating is sent to the next converter.

Under industrial conditions, the Klaus reaction on a catalyst grain of 3-8 mm proceeds in the region of intra-diffusion inhibition, and its observed rate is determined not only by the rate of the direct chemical reaction, but also by the rate of supply of reagents from the surface deeper into the grain along transport macropores with a diameter greater than 50 nm.

Thus, the degree of sulfur recovery in the second stage directly depends not only on the chemical and phase composition and volume of the mesopores (3-50 nm) of the catalyst, but also on the volume of macro- (50-1000 nm) and ultramacropores (> 1000 nm).

Also, the quality of the catalyst according to the Klaus process is determined by mechanical strength (not lower than 6 MPa), the shape of the particles (a spherical shape is preferable due to a more optimal hydrodynamic regime due to the regular packing of granules in the reactor) and bulk density. As a rule, the bulk density of most alumina catalysts exceeds 0.7 g / cm ³ . A decrease in bulk density below 0.7 g / cm ³ without loss of mechanical strength will allow for the previous catalyst loading volumes to provide an increase in the degree of sulfur recovery in existing industrial plants.

A known method of producing an alumina catalyst according to the Klaus process, which includes grinding of transition alumina with a specific surface area of 100 to 400 m ² / g to particles, most of which are less than 20 microns in size, followed by treatment in solutions of nitric, acetic acid or formic acid and subsequent plasticization of the product in the presence of urea [RU 2048908, B01J 21/04, 06/01/1992]. The plastic mass is extruded and calcined. The disadvantages of this method include the non-spherical shape of the particles; the use in the process of producing a catalyst of a large number of acids requiring neutralization; expensive stage of drying the hydrated product in a fluidized bed of an inert coolant; toxic urea combustion products (isocyanic acid, ammonia, cyanuric acid, triuret, melamine); low mechanical crush strength of the catalyst (1-5 MPa).

A known method of producing spherical aluminum oxide, used, inter alia, as a catalyst in the Klaus process [RU 2102321, C01F 7/02, 02.26.1996].

The essence of the invention lies in the fact that the oxygen-containing aluminum compounds of the type Al ₂ O ₃ · nH ₂ O are subjected to mechanochemical activation, after which the resulting product is rolled up to a spherical shape on a disk granulator, the obtained granules are passed through a special chamber where the specified partial pressure of water vapor is maintained at a temperature of 25-100 ° C for 1-5 hours, and then calcined at a temperature of 330-900 ° C. The result is alumina with a total pore volume of up to 0.53 cm ³ / g. The disadvantages of the technical solution include the following: conducting a separate stage of hydration of the granules in difficult technological conditions with the need to maintain a given partial pressure of water vapor; conducting a separate stage of drying the granules in the dryer; high air flow (up to 3000 h ^-1 ) at the calcination stage; high calcination temperature (up to 900 ° С).

The closest in composition and achieved effect is an industrial catalyst based on aluminum oxide ANKS-11K (http://niap-kt.ru/%D0%90%D0%9D%D0%9A%D0%A1-11) used for processing sulfur compounds according to the Klaus process, molded in the form of spheres and having a mechanical strength of at least 5.0 MPa, a large volume of meso- and macropores (0.33 and 0.15 cm ³ / g, respectively) and a low bulk density of 0, 67 g / cm ³ .

Closest to the method of preparation of the catalyst used for the processing of sulfur compounds by the Klaus process and molded in the form of extrudates or spheres is the method described in the inventions [RU 2103058, B01J 21/04, C01B 17/04 01/27/1998; RU 2112595, B01J 21/04, C01B 17/04, 06/10/1996].

The catalyst, which can be prepared according to this method of preparation, including the method of granular granulation, contains from 1200 to 2700 ppm Na ₂ O [RU 2103058, B01J 21/04, 07/13/95] and has a total volume created by all pores with a diameter above 0.1 μm, more than 12 ml / 100 g. The ratio of the total pore volume with a diameter above 1 μm to the total pore volume with a diameter above 0.1 μm of this catalyst is greater than or equal to 0.65 [RU 2112595, B01J 21/04, 12.07.95]. In the region indicated by the inventors, the highest conversion of CS ₂ is observed. The authors do not provide data on the activity of the catalyst in the Klaus reaction.

The disadvantage of the cooking method is the use of additional stages, leading to a significant complication of the technology and the cost of the catalyst: 1) washing with water the products of thermal activation from Na ⁺ ions; 2) preparation of the feedstock before granulation by mixing in a certain proportion of products washed and not washed from Na ₂ O; 3) autoclaving; 4) exposure of the granules at a given partial pressure of water vapor; 5) drying the granules in an oven. The catalyst prepared according to the method of this invention, with satisfactory characteristics of mechanical strength (8.8 MPa) and the volume of meso- and macropores (0.28 and 0.19 cm ³ / g, respectively) has a bulk density greater than 0.7 g / cm ³ .

The invention solves the problem of producing a highly efficient alumina catalyst according to the Klaus process with a bulk density not exceeding 0.7 g / cm ³ while maintaining a crushing mechanical strength of at least 6 MPa, a specific surface _{area of} S _{BET of} at least 280 m ² / g and a sodium oxide content of higher than 1500-1800 ppm, the operational characteristics of which are improved by optimizing the texture characteristics (volume of meso- and macropores) without additional stages: autoclaving, aging of granules at a given partial pressure of water vapor, drying of granules l in an oven, washing the thermal activation products of ions Na ^+.

The task of obtaining a highly efficient catalyst according to the Klaus process is solved by creating an alumina catalyst with a tridisperse porous structure consisting of meso-, macro- and ultramacropores, which contains χ-, γ-Al ₂ O ₃ and the x-ray amorphous phase of aluminum oxide in an amount wt.%: χ-Al ₂ O ₃ and the X-ray amorphous phase - 65-99.9, γ-Al ₂ O ₃ - 0,1-35, has a total pore volume determined by mercury porosimetry, 0.3-0.6 cm ³ / g, a mesopore volume of 3-10 nm diameter not less than 0,12-0,35 cm ³ / g, and the ratio of the volume of mesopores with a diameter of 3-10 nm to the volume at the tramakropor diameter above 1000 nm less than or equal to 5 and a bulk density in the range of 0.6-0.7 g / cm ³ at the mechanical crush strength is not less than 6 MPa.

According to the invention, it has been found that for fixed characteristics, such as particle size distribution, surface size and surface chemistry, the distribution of pore volume over radii in alumina catalysts is crucial for catalytic activity in the Klaus reaction, both in the kinetic region and in the region of intra-diffusion drag.

The problem is also solved by the method of preparation of the catalyst according to the Klaus process, in which the ground product of centrifugal thermal activation of hydrargillite or gibbeite (CTA), or ground thermally activated by disk granulation, is hydrated in closed containers, sieved to the target fraction, calcined in a stream of air or flue gases.

The CTA product is obtained with various physicochemical properties in a CEFLAR ™ drum-type centrifugal flash reactor developed at the Siberian Branch of the Siberian Branch of the Russian Academy of Sciences [RU 2264589, F25B 7/00, 11/20/2005]. The synthesis of the CTA product is based on pulsed dehydration of technical alumina hydrate for several seconds and its subsequent hardening. Depending on the conditions for the preparation of the CTA product (temperature, partial pressure of water vapor, contact time, etc.), the CTA product may contain crystalline trihydroxide, crystallized or fine crystalline boehmite, and an X-ray amorphous phase - hydroxyoxide with a gross composition of Al ₂ O ₃ · NH ₂ O, where n is the number of moles of water in the range of 0.1-0.4. Under certain synthesis conditions, the content of the X-ray amorphous phase can reach 100%. The dehydration of hydrargillite crystals (synonym: gibbsite) in a centrifugal flash reactor has the character of a pseudomorphic transition (keeping the shape and size of the original particles unchanged).

The TGA product (thermal activation of hydrargillite is carried out in a flue gas stream) is produced by Achinsk Alumina Refinery OJSC, according to TU 48-0114-80-93.

At the next stage, the CTA or TGA product, crushed in a vibratory ball mill or disintegrator to an average particle size of 5-35 μm, is dipped on a disk granulator with a plate diameter of 800-3500 mm at a rotation speed of 5 to 50 rpm. Moistening the charge is carried out with a binder, for example water. The pelletizing time is typically 10 to 30 minutes. As the target granule size is reached, as a rule, 2-8 mm under the action of centrifugal force, the granules are poured over the side of the plate and, using a conveyor belt, enter the hydration stage.

In order to form a tridisperse porous structure of the granule and control the ratio of pores with a diameter of 3-10 nm and pores with a diameter of more than 1000 nm, pore-forming burnable and / or non-burnable additives, such as polyvinyl alcohol (PVA), glycerin, wood flour, charcoal, are used at the granulation stage , carboxymethyl cellulose (CMC) and carboxyethyl cellulose (CEC) or aluminum compounds with a median particle size of 80-100 microns. Moreover, the additives can be used both in dry form and in the form of solutions. So, in the form of solutions, PVA, glycerin, CMC, CEC are added, and in the form of fine powders - wood flour and coal, aluminum compounds (hydrargillite, TGA, CTA). Water-soluble additives with a concentration of up to 5% wt. are introduced in the process of moistening the powder with CTA or TGA. Insoluble additives are introduced into the mixture in dry form in an amount of up to 85 wt.%.

The hydration of the granules with the aim of hardening and the formation of a certain phase composition is carried out in closed containers at a temperature of 60-95 ° C for 2-48 hours. The heating of the container is due to the exothermic process caused by hydration, that is, in fact due to self-heating of the granules. In this case, an additional supply of heat from outside for hydration is not required. As a result of hydration of the granules, up to 45% pseudoboehmite is formed, which leads to high mechanical strength of the granules.

After hydration, the containers are opened, the granules cool and dry. As the dry state is reached, the granules are continuously fed to the heat treatment step by means of an elevator. Moreover, the processing can be carried out without loss of quality in the flow of air, and in the flow of flue gases. The calcination temperature is 300-600 ° C, the residence time of the granules in the furnace is not more than 4-8 hours at a speed of heating the layer of granules to the calcination temperature of 20-200 ° C / h. Thermal treatment of granules, regardless of the type of coolant, is carried out at a volumetric air flow rate of at least 100 h ^-1 .

The result is an alumina catalyst with a tri-dispersed porous structure consisting of meso-, macro- and ultramacropores, which contains χ-, γ-Al ₂ O ₃ and the x-ray amorphous phase of aluminum oxide in the amount, wt.%: Χ-Al ₂ O ₃ and X-ray amorphous phase - 65-99.9, γ-Al ₂ O ₃ - 0.1-35.

The main advantages of the catalyst obtained by the proposed method are as follows. The method allows to obtain an alumina catalyst with a special - tridisperse - pore distribution. The catalyst has a mesopore volume of 3 to 10 nm in diameter, which is necessary to ensure high activity in the kinetic region of the Klaus reaction. In addition, in addition to the meso and macropores inherent in other catalysts according to the Klaus process, the proposed catalyst is also characterized by a significant volume of ultramacropores (with a diameter of more than 1000 nm). According to mercury porosimetry, the volume of such pores can reach 0.35 cm ³ / g. The ratio of the volume of mesopores with a diameter of 3-10 nm to the volume of ultramacropores with a diameter above 1000 nm is less than or equal to 5. Ultramacropores can significantly reduce the processes of intra-diffusion inhibition in the catalyst grain and increase the availability of mesopores. As a result, this catalyst according to the Klaus process allows, under the above-described conditions for determining catalytic activity, to provide a sulfur yield in the range of 40-60%, which is 55-85% of the thermodynamically possible sulfur yield.

The proposed method for producing a highly effective catalyst for the Klaus process provides a simplification of catalyst preparation technology by eliminating the technological stages of forced drying, autoclaving, mixing, and exposure of granules at a given partial pressure of water vapor. As a result, the complexity and energy intensity of the process are reduced by 30%.

The use of the claimed catalyst in comparison with the prototype can improve the efficiency of the Klaus process by 25-30%.

Alumina catalysts of the same chemical composition with a sodium hydroxide content (expressed in Na ₂ O) of 1800 ppm, having the same phase composition (15-20 wt.% Γ-Al ₂ O ₃ , 85-80 wt.% Χ-Al ₂ O ₃ and X-ray amorphous phase), with a volume of mesopores with a diameter of 3-10 nm in the range of 0.04-0.34 cm ³ / g and a ratio of the volume of mesopores with a diameter of 3-10 nm to the volume of ultra-macropores with a diameter above 1000 nm in the range of 0.4-12.5 formed by the method of disk granulation to obtain spherical granules with a diameter of 2.8-8 mm

The activity of the catalysts was tested in the Claus reaction.

The activity of the catalysts was determined by the sulfur yield in the reaction 2H ₂ S + SO ₂ ↔ 3 / nS _n + 2Н ₂ O. The reaction was carried out in a flow reactor with a diameter of 10 mm and a height of 80 mm at atmospheric pressure, temperature 220 ° C. A gas mixture (vol.%) Was used as the initial reaction mixture: 1.5H ₂ S + 0.75SO ₂ + 30H ₂ O; Not - to balance. To determine the activity of the catalyst in the kinetic region, the reaction was carried out on a catalyst fraction of 0.1-0.2 mm at a contact time of 0.02 s. The test time is 2 hours. To determine the activity of the catalyst in the field of intra-diffusion inhibition, the reaction was carried out on catalyst granules with a diameter of 4-5 mm at a contact time of 0.2 s. The test time is 3 hours.

The activity of the catalysts was evaluated after obtaining a stable plateau of the content of reaction products at the outlet of the reactor from the observed rate of sulfur formation in the Claus reaction. The observed values of the conversion of the components (X _i ) and the yield of sulfur (Y) were calculated by the formulas:

конечная и исходная концентрации компонента, измеренные в осушенных пробах (% об.);where i is the index of the component (H ₂ S or SO ₂ ), C _i and $$C_i^o$$

final and initial component concentrations measured in dried samples (% vol.);

The observed sulfur output rate, normalized to the specific surface, was determined by the formula:

where U is the flow rate of the dry gas mixture (l / h), V is the molar volume of gas (l / mol), m is the mass of the catalyst (g), S _beats is the specific surface area of the catalyst (m ² / g).

The data characterizing the physicochemical properties and activity of the catalysts are presented in FIGS. 1a and b and in Tables 1 and 2. FIG. 1 illustrates the effect of the porous structure on the activity of alumina-based catalysts in the Claus reaction.

Figa illustrates the dependence of the activity of the catalysts in the kinetic region of the reaction from the volume of mesopores with a diameter of 3-10 nm. Table 1 shows the values of the rate of formation of sulfur for the catalysts used to determine the activity in the kinetic region of the reaction, and the prototype catalyst - alumina catalyst brand ANX-11K, their total pore volume and specific surface area.

Fig.1b illustrates the dependence of the activity of the catalysts in the diffusion region of the reaction on the ratio of the volume of mesopores with a diameter of 3-10 nm to the volume of ultramacropores with a diameter above 1000 nm with a volume of mesopores with a diameter of 3-10 nm not lower than 0.12 nm. Table 2 shows the sulfur yield values for the catalysts used to determine the activity in the diffusion region of the reaction and the prototype catalyst — the ANX-11K alumina catalyst, their strength and bulk density.

From the data presented in Fig. 1a, it is seen that on catalysts with a mesopore volume of 3-10 nm in diameter below 0.1 cm ³ / g, the rate of sulfur formation (W) is relatively low. These catalysts also have relatively low total pore volume (less than 0.3 cm ³ / g) and specific surface area (less than 280 m ² / g) (Table 1). To achieve maximum catalytic activity, the mesopore volume (d = 3-10 nm) should be at least 0.12 cm ³ / g. The total pore volume of these catalysts is higher than 0.3 cm ³ / g, and the specific surface area is not lower than 280 m ² / g.

From the data presented in Fig.1b and in table 2, it is seen that the sulfur yield decreases with increasing ratio V _{por3-10 nm} / V _{por> 1000 nm} . On catalysts in which the ratio of V _{por3-10 nm} / V _{por> 1000 nm is} less than 5, the sulfur yield exceeds 40%. Catalysts in which V _{por3-10 nm} / V _{por> 1000 nm are} less than 3 are even more effective (the sulfur yield on these catalysts is above 50%) and have a reduced bulk density (not higher than 0.7 g / cm ³ ). However, catalysts with a ratio of V _{por3-10 nm} / V _{por> 1000 nm are} less than 1, having maximum activity in the diffusion region of the reaction, have low mechanical strength (below 6 MPa).

From a comparison of the characteristics of the claimed catalyst and the prototype catalyst (ANKS-11K) having the same chemical and phase composition, it can be seen that these catalysts have a specific surface area above 280 m ² / g, mesopore volume V _{por 3-10 nm} above 0.12 cm ³ / g, bulk density below 0.7 g / cm ³ are characterized by comparable catalytic activity in the kinetic region (table 1). However, the claimed catalyst has significantly lower values for the ratio of V _{pores of 3-10 nm} / V _{pores> 1000 nm} and, accordingly, a significantly higher activity in the diffusion region than the prototype catalyst (table 2).

The essence of the invention is illustrated by the following examples and tables 3, 4.

Example 1

The feedstock is the product of centrifugal thermal activation of hydrargillite, having the composition Al ₂ O _3-0.28 (OH) _0.28 · 0.1H ₂ O and containing (without additional washing or mixing steps) 1500-1800 ppm Na ₂ O, crushed in a continuous ball mill to particles with an average size of 5-35 microns. In pneumatic transport mode, the ground CTA product is fed to a disk granulator. Raw material consumption is 60 kg / h. At the same time, a moisturizing solution containing a pore-forming burn-out additive - polyvinyl alcohol (PVA) with a concentration of 5 wt.% Is fed through the nozzle. Also through the second dispenser serves pore-forming non-burning additive - a CTA product with an average particle size of 80-100 microns. Additive consumption is 340 kg / h. The percentage of feedstock and non-fading additives is 15/85.

Pelletization is carried out continuously. Upon reaching a certain size (in the range of 2.8-8 mm), the granules are poured over the edge of the granulator under the action of centrifugal force and, with the help of a belt conveyor, enter the containers for hydration. The containers are closed, and due to the exothermic reaction, the mass in them is heated to a temperature of 60-95 ° C. The granules are kept in containers for hydration for 4 hours, after which they are opened and dried in air. At the end of the process, the granules are calcined in a continuous furnace at a temperature of 450 ° C for 4 hours at a rate of heating the layer to an annealing temperature of 20 ° C / h and a space velocity of air supply of 100 h ^-1 .

Example 2

Example 2 is similar to example 1, with the following changes:

- the composition of the feedstock - the product of centrifugal thermal activation of hydrargillite - Al ₂ O _3-0.14 (OH) _0.14 · 0.2H ₂ O;

- the moisturizing solution does not contain a burnable additive;

- the percentage of feedstock and non-fading additives is 98/2;

- the granules are kept in containers for hydration for 48 hours;

- calcination of the granules is carried out at a temperature of 400 ° C for 8 hours at a volumetric air flow rate of 1000 h ^-1 .

Example 3

Example 3 is similar to example 2, with the following changes:

- the composition of the feedstock - the product of centrifugal thermal activation of hydrargillite - Al ₂ O ₃ · 0,4N ₂ O;

- as a non-burning pore-forming additive, thermally activated aluminum hydroxide with an average particle size of 80-100 microns is used;

- the percentage of feedstock and non-fading additives is 70/30;

- the granules are kept in containers for hydration for 2 hours;

- annealing of the granules is carried out at a temperature of 450 ° C for 4 hours at a rate of heating the layer to an annealing temperature of 100 ° C / h.

Example 4

Example 4 is similar to example 2, with the following changes:

- as raw materials, crushed in a disintegrator to particles with an average size of 5-35 microns is used thermally activated aluminum hydroxide having an Al ₂ O _3-0,2 (OH) composition of _0.2 · 0.25H ₂ O;

- the percentage of feedstock and non-fading additives is 15/85;

- as a non-burning pore-forming additive, the product of centrifugal thermal activation of hydrargillite with an average particle size of 80-100 microns is used;

- granules are kept in containers for hydration for 10 hours;

- calcination of the granules is carried out at a temperature of 300 ° C for 8 hours

Example 5

Example 5 is similar to example 4, with the following changes:

- as pore-forming non-burning additives using hydrargillite with an average particle size of 80-100 microns,

- the percentage of feedstock and non-fading additives is 20/80;

- the granules are kept in containers for hydration for 4 hours;

- calcination in a continuous furnace is carried out at a temperature of 450 ° C for 4 hours at a rate of heating of the layer to a calcination temperature of 100 ° C / h.

Example 6

Example 6 is similar to example 4, with the following changes:

- charcoal is used as a pore-forming non-burning additive;

- the granules are kept in containers for hydration for 48 hours;

- calcination of the granules is carried out at a temperature of 600 ° C for 4 hours and the speed of heating the layer to an calcination temperature of 200 ° C / h.

The percentage of raw materials and non-fading additives is 85/15

Example 7

Example 7 is similar to example 2, with the following changes:

- wood flour is used as a pore-forming non-burning additive;

- the granules are kept in containers for hydration for 48 hours;

- calcination of the granules is carried out at a temperature of 550 ° C for 8 hours at a rate of heating the layer to an calcination temperature of 200 ° C / h.

The percentage of feedstock and non-burning additives is 95/5.

Example 8

Example 8 is similar to example 1, except that the process does not use non-combustible pore-forming additives, and carboxyethyl cellulose with a concentration of 1 wt.% Is introduced into the moisturizing solution as a pore-forming additive.

Example 9

Example 9 is similar to example 8, except that carboxymethyl cellulose with a concentration of 3 wt.% Is added as a burnable pore-forming additive to the moisturizing solution.

Example 10

Example 10 is similar to example 8, except that the starting material used is a centrifugal thermal activation product of hydrargillite with an average particle size of 5-35 μm, and glycerol with a concentration of 5 wt.% Is introduced into the fountain solution as a burnable pore-forming additive.

Example 11

Example 11 is similar to example 1, except that the process does not use pore-forming additives.

Example 12 - a prototype of the method of preparation

Hydrargillite is dehydrated rapidly at 800 ° C using a hot gas stream to produce product A containing 3600 ppm Na ₂ O. Part of product A is introduced into an autoclave with distilled water with a pH of 7. The autoclave is shaken and heated for 5 hours at 135 ° C. The resulting alumina suspension was dried for 3 hours at 110 ° C, calcined at 600 ° C, and product B was obtained with a Na ₂ O content of 800 ppm. Mix products A and B in a ratio of 50:50. Then they are granulated into balls with a diameter between 3.1 and 6.3 mm. The content of Na ₂ O in these balls is about 0.2 wt.%.

The conditions for the preparation of catalysts and their characteristics are presented in tables 3 and 4, respectively.

The data presented in table 4 allow us to conclude that the catalyst obtained by the proposed method, not inferior in activity, strength and specific surface area to the catalyst obtained by the prototype method, has a lower bulk density.

As a result of using the proposed method, the technology for producing a catalyst is simplified due to the fact that the hydrothermal treatment, drying in an oven, preparation of raw materials before granulation by mixing in a certain proportion of products washed and not washed from Na ₂ O are excluded from the process.

Table 3 The conditions for obtaining samples of alumina catalyst according to examples 1-11 Example No. Feedstock composition Pore-forming additives,% wt. Stage Parameters Non-playing Burnout _hydration , h Calcination T, ° C τ, h U _T , ° C · h ^-1 V _gas , h ^-1 one Al ₂ O _3-0.28 (OH) _0.28 · 0.1H ₂ O 85 CTA 5 PVA four 450 four twenty one hundred 2 Al ₂ O _3-0.14 (OH) _0.14 · 0.2H ₂ O 2 CTA - 48 400 8 200 1000 3 Al ₂ O ₃ · 0.4H ₂ O 30 TGA - 2 450 four one hundred 1000 four Al ₂ O _3-0.2 (OH) _0.2 · 0.25H ₂ O 15 CTA - 10 300 8 twenty 1000 5 Al ₂ O _3-0.2 (OH) _0.2 · 0.25H ₂ O 80 Hydrargillite - four 450 four one hundred one hundred 6 Al ₂ O _3-0.2 (OH) _0.2 · 0.25H ₂ O 15 remote control - 48 600 four 200 1000 7 Al ₂ O _3-0.14 (OH) _0.14 · 0.2H ₂ O 5 DM - 48 550 8 200 1000 8 Al ₂ O _3-0.28 (OH) _0.28 · 0.1H ₂ O - 1 KEC four 450 four twenty one hundred 9 Al ₂ O _3-0.28 (OH) _0.28 · 0.1H ₂ O - 3 CMC 6 450 four twenty one hundred 10 Al ₂ O _3-0.28 (OH) _0.28 · 0.1H ₂ O - 5 Glycerin four 450 four twenty one hundred eleven Al ₂ O _3-0.28 (OH) _0.28 · 0.1H ₂ O - - twenty 400 four twenty one hundred

Table 4 Physico-chemical properties of alumina catalysts and their activity in the Klaus reaction under conditions of intra-diffusion inhibition The catalyst according to example No. The phase composition,% S _BET , m ² / g ΣV _then cm ³ / g V _{3-10 nm} , cm ³ / g ρ, g / cm ³ R, MPa The yield of sulfur,% PA + χ-Al ₂ O ₃ γ-Al ₂ O ₃ one 73 27 354 0.45 0.18 1,2 0.65 6.4 53 2 75 25 320 0.32 0.12 3.0 0.64 8.9 48 3 70 thirty 315 0.48 0.22 2,4 0.67 7.3 fifty four 70 thirty 312 0.46 0.12 3,7 0.66 10,2 45 5 70 thirty 318 0.44 0.20 4.1 0.69 12.0 43 6 65 35 332 0.60 0.16 0.4 0.61 5,0 58 7 65 35 341 0.53 0.15 1,0 0.63 6.1 58 8 75 25 342 0.49 0.28 4.7 0.75 12.5 43 9 75 25 358 0.60 0.35 5,0 0.74 10.1 41 10 85 fifteen 365 0.40 0.25 2,5 0.67 8.2 49 eleven 45 PBe, 55 (RA + χ-Al ₂ O ₃ ) 279 0.22 0.20 7.3 0.90 19.0 26 12* 80 twenty 362 0.48 0.28 2,3 0.71 8.8 47 * A catalyst sample was prepared according to the prototype method.

Claims (11)

1. The catalyst for the production of elemental sulfur according to the Claus process based on aluminum oxide, which is a mixture of χ-, γ-Al ₂ O ₃ and the X-ray amorphous phase of aluminum oxide in the following ratio, wt.%:
χ-Al ₂ O ₃ and X-ray amorphous phase 65-99.9 γ-Al ₂ O ₃ 0.1-35,
characterized in that in the catalyst the volume of mesopores with a diameter of 3 to 10 nm is 0.12-0.35 cm ³ / g, and the ratio of the volume of mesopores with a diameter of 3-10 nm to the volume of ultra-macropores with a diameter above 1000 nm is less than or equal to 5. 2. The catalyst according to claim 1, characterized in that it has a total pore volume of 0.3-0.6 g / cm ³ with a specific surface area of at least 280 m ² / g. 3. The catalyst according to claim 1, characterized in that it has a bulk density in the range of 0.6-0.7 g / cm ³ with a mechanical crushing strength of at least 6 MPa. 4. A method of preparing a catalyst for the production of elemental sulfur according to the Klaus process, comprising the step of granulating nanostructured thermally activated aluminum hydroxide, hydrating freshly formed spherical granules in insulated containers, drying and heat treatment, characterized in that at the stage of granulating into a nanostructured oxygen-containing aluminum compound containing not more than 1500 -1800 ppm Na ₂ O, injected blowing burnable and / or nevygorayuschie additives, thereby obtaining the catalyst n any one of claims 1-3. 5. The method according to claim 4, characterized in that the hydration of the freshly formed granules is carried out in saturated water vapor due to self-heating of the granules at a temperature of 60-95 ° C for 2-48 hours 6. The method according to claim 4, characterized in that the heat treatment of the granules is carried out in a stream of air at a temperature of 300-600 ° C for 4-8 hours at a speed of heating the layer of granules to an annealing temperature of 20-200 ° C / h. 7. The method according to claim 6, characterized in that the heat treatment of the granules is carried out at a space velocity of air supply of at least 100 h ^-1 . 8. The method according to claim 4, characterized in that aluminum compounds with an average particle size of 80-100 microns, such as hydrargillite (gibbsite), thermally activated aluminum hydroxide, a product of centrifugal thermal activation of hydrargillite in an amount of up to 85 wt., Are used as pore-forming non-burning additives. .%. 9. The method according to claim 4, characterized in that, for example, charcoal, wood flour in an amount of up to 15 wt.% Are used as pore-forming burnable additives. 10. The method according to claim 4, characterized in that the solutions of polyvinyl alcohol, glycerol, carboxymethyl cellulose and carboxyethyl cellulose with a concentration of up to 5 wt.% Are used as pore-forming burnable additives. 11. The method of carrying out the Klaus process, which consists in passing gases containing sulfur compounds through a fixed catalyst bed based on aluminum oxide, characterized in that they use the catalyst defined in claims 1-3 or obtained by the method according to any of claims 4-10 .

Images