RU2622037C1 - Regenerated catalyst of hydraulic cleaning - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a regenerated diesel fuel hydrotreating catalyst that has a pore volume of 0.3-0.8 ml/g, a specific surface area of 150-280 m²/g, an average pore diameter of 6-15 nm, including molybdenum, cobalt, sulfur and a carrier in its composition. In this case, molybdenum and cobalt are contained in the catalyst in the form of a mixture of complex compounds Co(C₆H₆O₇), H₄[Mo₄(C₆H₅O₇)₂O₁₁], H₃[Co(OH)₆Mo₆O₁₈], sulfur is contained in the form of sulfate anion SO₄ ^2-, in the following concentrations, wt %: Co(C₆H₆O₇) - 5,1-18,0; H₄[Mo₄(C₆H₅O₇)₂O₁₁] - 7,5-15,0; H₃[Co(OH)₆Mo₆O₁₈] - 4,3-19,0; SO₄ ^2- - 0,5-2,30; the carrier is the rest, while cobalt citrates can be coordinated to molybdenum citrate H₄[Mo₄(C₆H₅O₇)₂O₁₁] and to the 6-molybdocobaltate H₃[Co(OH)₆Mo₆O₁₈].

EFFECT: invention makes it possible to obtain regenerated catalysts whose activity in the hydrotreating of diesel fuel is 100 percent or more of the activity of fresh catalysts.

3 cl, 2 tbl, 6 ex

Description

The invention relates to regenerated hydrotreating catalysts for producing low sulfur diesel fuel.

At present, the Russian oil refining industry produces diesel fuels with a sulfur content of not more than 10 ppm, which comply with EURO-5 and similar Russian standards [GOST R 52368-2005. (EN 590-2004). Diesel fuel EURO. Specifications]. The production of such low-sulfur fuels is achieved by deep hydrotreating straight-run or mixed diesel fractions only when using highly active catalysts that provide a degree of hydrodesulfurization of at least 99%. This degree of desulfurization is achievable only on modern catalysts of the latest generation.

During operation, the catalysts inevitably deactivate and need regeneration. For regeneration, oxidative removal of carbon deposits is used - the main reason for deactivation, however, the oxidative regeneration of modern highly active hydrotreating catalysts allows their activity to be restored by no more than 90%, which is insufficient for reuse of the catalysts in the processes of producing EURO-5 low-sulfur diesel fuels. In this regard, it is necessary to develop regenerated deep hydrotreating catalysts having an activity of at least 99% of the activity of fresh catalysts.

Many different methods for the regeneration of deactivated hydrotreating catalysts are described, however, their common drawback is the insufficiently complete restoration of activity.

Known methods of non-reactor regeneration described in [M. Marafi, A. Stanislaus, E. Furimsky. Handbook of spent hydroprocessing catalysts - regeneration, rejuvenation and reclamation, Elsevir, BV, Amsterdam, 2010. P. 362]. In these methods, spent catalyst is discharged from the reactor and regenerated in one of the following ways:

1. Regeneration in a tunnel kiln, divided into several temperature zones. A thin layer of catalyst is fed to the first tape with small holes, which moves at high speed. Here the main part of coke deposits is removed. The catalyst is then transferred to a second belt, moving at a lower speed, at which the regeneration process is completed. Temperature control and removal of excess heat is carried out by supplying cold air through a catalyst bed. [C. Vuitel, NPRA Ann. Meeting, Oct. 8-10, 1997].

2. Regeneration in a rotary inclined furnace, in which there are ribs and rings forming a catalyst layer. Temperature control and removal of excess heat is carried out by air flow over the catalyst bed [J. Wilson, AIChE Meeting, Aug. 19-22, San Diego, CA, 1990].

3. Regeneration in two successive fluidized bed reactors. The mixing of the catalyst bed is ensured by the supply of air to the bottom of the reactors. Temperature control is carried out due to the flow rate and air temperature, temperature in the jacket of the reactor and the level of catalyst in the reactor. [D.J. Neuman, NPRA Ann. Meeting, March 19-21, San Francisco, CA, 1995, pap. AM-95-41].

The main disadvantage of these methods is that the regenerated catalysts are significantly inferior in activity to fresh catalysts.

To increase the activity of regenerated catalysts, they are treated with various activating agents after oxidative regeneration.

A known method of increasing the activity of regenerated catalysts [US No. 7087546, B0J 20/34; EP No. 1418002 A2, B01J 23/85, C10G 45/08], by impregnating them with solutions of carboxylic acids, glycols, carbohydrates containing from 1 to 3 carboxyl groups and 2-10 carbon atoms. The catalyst is impregnated with solutions of these compounds in various molar ratios and then dried at various temperatures. Compounds containing an amino group (—NH ₂ ), a hydroxo group (—OH), a carboxyl group (—COOH) can also be used as an organic additive.

So in [WO 2005070542, A1, B0J 38/48] a method is described for restoring the activity of catalysts by treating them with ethylene diamine tetraacetic, nitrilotriacetic, hydroxyethylene diamine triacetic acids. After oxidative regeneration, the catalyst is impregnated with solutions of the above additives, with a molar ratio of 0.01-0.5 mol additives per mole of active metals in the catalyst, drying the catalysts at 120 for 2 hours and subsequent calcination at 450 ° C.

The known catalyst, regeneration method and hydrotreatment method proposed in [RF No. 2351634, C10G 45/08, B01J 37/02,] according to which the regenerated catalyst contains a group VIII metal oxide and a group VI metal oxide, further comprises an acid and an organic additive, which has a boiling point in the range of 80-500 ° C and a solubility in water of at least 5 g per liter, the catalyst containing a crystalline fraction expressed as the weight of the fraction of crystalline compounds of metals of group VIB and group VIII relative to the total weight of cat analyzer, in an amount of less than 5 wt. % A known regeneration method involves contacting the catalyst with an acid and an organic additive that has a boiling point in the range of 80-500 ° C and a solubility in water of at least 5 g per liter, optionally followed by drying under such conditions that at least 50 wt. % of the additive remains in the catalyst. A known method of hydrotreating consists in contacting the hydrocarbon feed with a catalyst regenerated by the above method.

A common disadvantage for the above regenerated catalysts is their insufficiently high activity, due to the non-optimal, complex and unidentifiable chemical composition of the resulting catalysts.

The closest in technical essence and the achieved effect to the claimed regenerated catalyst is the catalyst proposed in [RF No. 2484896, B01J 23/94, C10G 45/08, B01J 37/02].

According to the prototype, the regenerated catalyst contains molybdenum, and cobalt in the form of citrate complex compounds Co (C ₆ H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], and sulfur is contained in the form of sulfate- anion SO ₄ ^2- in the following concentrations, wt. %: Co (C ₆ H ₆ O ₇ ) - 7.3-16.6; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 17.3-30.0; SO ₄ ^2- - 0.25-2.70; the carrier is the rest, while cobalt citrates can be coordinated to molybdenum citrate.

The main disadvantage of the prototype, as well as other known regenerated catalysts, is their insufficiently high activity in hydrotreating. The low level of activity of the obtained catalysts is explained by their non-optimal chemical composition.

The present invention solves the problem of creating an improved regenerated hydrotreating catalyst, characterized by:

1. The optimal chemical composition of the catalyst containing cobalt and molybdenum in the form of complex compounds, which then turn into the most active component of hydrotreating catalysts.

2. The optimal texture characteristics of the catalysts, providing good access of sulfur-containing raw material molecules to the active component, which leads to the production of petroleum products with a low sulfur content.

3. The presence in the composition of the catalyst carrier based on alumina Al ₂ O ₃ containing additional components selected from the series: Fe, Si, P, B, Ti, Zr, F, Mg, La in the claimed concentrations, as contributing to further selective production sulfide active component, as well as promoting the activity of catalysts in the target hydrotreatment reactions.

4. The low sulfur content in the resulting petroleum products, achieved through the use of the inventive catalysts regenerated by the claimed methods.

The problem is solved by a regenerated hydrocarbon hydrotreating catalyst, which contains molybdenum and cobalt in the form of a mixture of complex compounds Co (C ₆ H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ], sulfur in the form of sulfate anion SO ₄ ^2- , in the following concentrations, wt. %: Co (C ₆ H ₆ O ₇ ) - 5.1-18.0; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 7.5-15.0; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - 4.3-19.0; SO ₄ ^2- - 0.5-2.30; the carrier is the rest, while cobalt citrates can be coordinated to molybdenum citrate H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] and to 6-molybdocobaltate H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ].

The main distinguishing feature of the proposed regenerated catalyst in comparison with the prototype is that the catalyst contains molybdenum and cobalt in the form of a mixture of complex compounds Co (C ₆ H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ], sulfur in the form of the sulfate anion SO ₄ ^2- , in the following concentrations, wt. %: Co (C ₆ H ₆ O ₇ ) - 5.1-18.0; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 7.5-15.0; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - 4.3-19.0; SO ₄ ^2- - 0.5-2.30; the carrier is the rest, while cobalt citrates of Co (C ₆ H ₆ O ₇ ) can be coordinated to molybdenum citrate H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] and to 6-molybdocobaltate H ₃ [Co ( OH) ₆ Mo ₆ O ₁₈ ].

A distinctive feature of the proposed regenerated catalyst is also that the catalyst carrier is an alumina Al ₂ O ₃ containing at least one component selected from the series: Fe, Si, P, B, Ti, Zr, F, Mg, La, with the total concentration of additional components in the carrier of 0.1-5.0 wt. %

The technical effect of the proposed regenerated hydrotreating catalyst consists of the following components:

1. The inventive chemical composition of the catalyst and its texture provide maximum activity in the target reactions occurring during hydrotreatment of hydrocarbon feedstocks. The presence in the composition of the catalysts of citrate complexes of cobalt and molybdenum, as well as bimetallic 6-molybdocobaltate H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] in the claimed concentrations, selectively turning into the most active component of catalysis, determines the optimal surface concentration of the active component and the optimal morphology particles.

2. The presence in the composition of the catalyst sulfur in the form of surface sulfates in the claimed concentrations minimizes the undesirable interaction of active metals with the surface of the carrier, which leads to the formation of compounds that are inactive in catalysis.

3. The presence in the composition of the catalyst carrier containing additional components in the claimed concentrations, provides further obtaining the active component of the optimal structure and morphology.

4. The claimed texture characteristics of the resulting catalyst provide good access to the raw material molecules to be converted to the active component.

5. Hydrotreating diesel fuel in the presence of a catalyst of the claimed chemical composition allows to obtain diesel fuel containing not more than 10 ppm sulfur at low starting temperatures of the process, which predicts a long life of the catalyst.

Description of the proposed technical solution.

For regeneration, catalysts are used that are deactivated during their operation in hydrotreating various hydrocarbon feedstocks. Typically, the catalysts contain, by weight. %: 5.0-25.0 carbon; 5.0-15.0 sulfur; 0.1-2.5 nitrogen; 8.0-16.0 wt. % Mo, 2.0-5.5 wt. % Co, the carrier is the rest. The carrier is an aluminum oxide Al ₂ O ₃ additionally containing at least one component from the series: Fe, Si, P, B, Ti, Zr, F, Mg, La with a total concentration of 0.1-5.0 wt. %

The deactivated catalyst is calcined in air so that the temperature at any point in the catalyst layer does not exceed 650 ° C. For this, either a thin catalyst layer is used, the minimum thickness of which is equal to the thickness of one granule, and the maximum thickness does not exceed 30 mm, or the calcination is carried out in a flow tube furnace with continuous mixing of the catalyst layer.

The temperature of the layer is controlled, on the one hand, by the temperature of the furnace heating elements, and, on the other hand, by the air flow rate, which has two functions, it supplies the amount of oxygen needed to completely burn out carbon deposits and oxidize surface metal sulfides, and also removes the main amount from the catalyst layer heat released during combustion. Since in this case the burning of carbon deposits occurs in an excess of oxygen, coke does not graphitize and all deposits burn out completely at a relatively low temperature.

The oxidative regeneration procedure is carried out according to one of two options:

1. A portion of the catalyst is placed on a stainless steel mesh pan with a mesh size of 1 mm so that the thickness of the catalyst layer does not exceed 30 mm. The pan is placed in a muffle furnace and serves air with a flow rate of 1500-2500 h ^-1 so that the air passes through the catalyst bed. Next, calcining is carried out according to the following program - heating from room temperature to a regeneration temperature not exceeding 650 ° C for 1-2 hours, calcining at a regeneration temperature for 0.5-4 hours, cooling to room temperature for 1-2 hours .

2. A portion of the catalyst is placed at the entrance of an inclined drum furnace with electric heating, which has three heating zones, and air supply to the furnace begins with a flow rate of 1500-2500 h ^-1 . The temperature of the first zone changes from room temperature at the entrance to no more than 650 ° C at the end of the zone, the temperature of the second zone is equal throughout the zone - no more than 650 ° C, the temperature of the third zone changes from the temperature of the second zone to room temperature. The length of the zones and the rotational speed of the furnace drum are selected so that the catalyst is in the first zone for 1-2 hours, in the second zone 0.5-4 hours, in the third zone 1-2 hours

Such calcination conditions simulate well the conditions of industrial belt and drum furnaces and ensure complete removal of carbon deposits in the absence of sintering of the catalyst.

The catalyst obtained after oxidative regeneration has a pore volume of 0.3-0.8 ml / g, a specific surface area of 150-280 m ² / g, an average pore diameter of 6-15 nm, and contains, wt. %: Co - 2.0-5.5; Mo - 10.0-16.0; S 0.2-0.8; C - not more than 0.2.

Next, prepare a solution of citric acid with a concentration of 1.3-2.5 mol / L. To do this, in a given volume of a mixture of water with 10-20 wt. % butyldiglycol with stirring and heating dissolve the required amount of citric acid.

Next, a portion of the calcined catalyst is impregnated with the resulting solution. The impregnation is carried out according to moisture capacity, then the wet catalyst is mixed in a flask of a rotary evaporator without air supply at a temperature of 60-90 ° C for 20-60 minutes under conditions that exclude complete evaporation of water from the catalyst.

Next, the catalyst is dried in air at a temperature of 100-220 ° C for 2-6 hours

The presence of Co, Mo complexes, and surface sulfates in the catalyst composition is confirmed by a combination of the following research methods: mass elemental analysis of Co, Mo, C, H, S; IR; RFE and EXAFS spectroscopy.

In all cases, the mass content of elements corresponds to the concentration in the finished catalyst, Co (C ₆ H ₆ O ₇ ) - 5.1-18.0; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 7.5-15.0; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - 4.3-19.0; SO ₄ ^2- - 0.5-2.30; the carrier is the rest.

The IR spectra of the studied catalysts contain bands corresponding to Co (C ₆ H ₆ O ₇ ); H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] and H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] (table 1).

The assignment of bands in the IR spectra is made in accordance with [S.M. Zimbler, L.L. Shevchenko, V.V. Grigoryeva. Journal of Applied Spectroscopy, 11 (1969) 522-528; R.I. Bickley, H.G.M. Edwards, R. Gustar, S.J. Rose, Journal of Molecular Structure, 246 (1991) 217-228; M. Matzapetakis, M. Dakanali, C.P. Raptopoulou, et al. Journal of Biological Inorganic Chemistry 5 (2000) 469-474; N.W. Alcock, M. Dudek, R. Grybos et al. J. Chem. Soc. Dalton trans. (1990) 707-711; C.I. Cabello et al. Journal of Molecular Catalysis A: Chemical 186 (2002) 89-100].

In the XPS spectra, there are peaks corresponding to Co (C ₆ H ₆ O ₇ ) —Co2p3 / 2 = 782.0 eV; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - Mo3d5 / 2 = 232.4 eV; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - Mo3d5 / 2 = 232.6 eV and Co2p3 / 2 = 781.6 eV with the Co ³⁺ satellite with a binding energy of 791.4 eV; SO ₄ ^2- - S2p = 169.3 eV. Assignments are made in accordance with [V.I. Nefedov, X-ray electron spectroscopy of chemical compounds. M. Chemistry. 1984, 256 pp.]. The peak intensities in the XPS spectra allow one to determine the concentration of each component in the catalyst.

; Н₄[Мо₄(C₆H₅O₇)₂O₁₁] - Мо-O=1,75 и 1,95

; Мо-Мо=3,40 и 3,69

; H₃[Co(OH)₆Mo₆O₁₈] - Мо-O=1,71; 1,95 и 2,30

; Мо-Мо=3,32

; Мо-Со=3,69

.For regenerated catalysts on the curves of the radial distribution of atoms obtained by the Fourier transform of the EXAFS spectra, the distances corresponding to Co (C ₆ H ₆ O ₇ ) - Co-O = 2.02 were recorded

; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - Mo — O = 1.75 and 1.95

; Mo-Mo = 3.40 and 3.69

; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - Mo — O = 1.71; 1.95 and 2.30

; Mo-Mo = 3.32

; Mo-Co = 3.69

.

As a result of regeneration according to the above-described method, catalysts are obtained having the claimed texture characteristics and containing complex compounds Co (C ₆ H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] and surface sulfates SO ₄ ^2- , as well as a carrier in the claimed concentration ranges.

Next, hydrotreating of diesel fuel is carried out at a volumetric feed rate in the range of 1-2.5 h ^-1 , a hydrogen / feed ratio of 300-600 nm ³ N ₂ / m ^{3 of} feedstock, a temperature of 340-390 ° C, a hydrogen pressure of 3- 9 MPa.

As raw materials use diesel fuel having a boiling range: 201-375 ° C; sulfur content: 0.355 wt. %; density 0.861 g / cm ³ ; or diesel fuel having a boiling range: 180-365 ° C; sulfur content: 1.0 wt. %; density 0.85 g / cm ³ .

For testing in hydrotreating, the catalysts are used in the form of extrudates with a cross section in the form of a shamrock or four-leaf with a diameter of the circumscribed circle of 1.3-1.6 mm and an average length of granules of 3-6 mm.

The preliminary sulfidation of the catalysts is carried out directly in the hydrotreatment reactor with a straight-run diesel fraction containing an additional 1.5 mass. % sulfidizing agent - dimethyldisulfide (DMDS), with a volumetric flow rate of sulfidizing mixture of 2 h ^-1 and a hydrogen / feed ratio = 300. Sulfidation involves several stages:

- drying the catalyst in a hydrotreatment reactor in a stream of hydrogen at 140 ° C for 2 hours;

- wetting the catalyst straight run diesel fraction for 2 hours;

- supply of a sulfidizing mixture and an increase in temperature to 240 ° C at a rate of temperature rise of 25 ° C / h;

- sulfidation at a temperature of 240 ° C for 8 hours (low temperature stage);

- increasing the temperature of the reactor to 340 ° C with a rate of temperature rise of 25 ° C / h;

- sulfidation at a temperature of 340 ° C for 8 hours (high temperature stage).

The invention is illustrated by the following examples:

Example 1. According to a known solution.

The catalyst that was used for 24 months in the process of hydrotreating diesel fuel is regenerated. The deactivated catalyst contains, by weight. %: C - 11.1; S is 5.6; Co - 1.72; Mo - 7.0; the carrier is the rest. The catalyst has a specific surface area of 111 m ² / g, an average pore diameter of 13 nm and a pore volume of 0.18 cm ³ / g. The catalyst carrier contains modifying additives in a total amount of 5.0 wt. % - 4.0% Si and 1.0% R.

Oxidative regeneration is carried out, for which 100 g of deactivated catalyst are placed on a stainless steel mesh pan with a mesh size of 1 mm and a total area of 60,000 mm ² . The pallet is placed in a muffle furnace and serves air with a flow rate of 0.25 m ³ / hour. The catalyst is calcined according to the following program — warming from room temperature to 550 ° C for 2 hours, calcining at 550 ° C for 4 hours, cooling to room temperature for 2 hours.

The catalyst after oxidative regeneration contains, by weight. %: CoO - 2.5; MoO ₃ - 12.0; SO ₄ ^2- - 0.3; C 0.2; the carrier is the rest; and has a specific surface area of 150 m ² / g, an average pore diameter of 15 nm and a pore volume of 0.3 cm ³ / g.

A solution of citric acid in water is prepared having a concentration of 2.5 mol / L. A portion of 20 g of the catalyst after oxidative regeneration is impregnated with a moisture capacity of 6 ml of citric acid solution with periodic stirring, after which it is dried for 0.5 h at 50 ° C, then 0.5 h at 220 ° C. Before determining the texture characteristics, the catalyst is heated in air for 2 hours at 500 ° C.

The resulting catalyst contains, by weight. %: Co (C ₆ H ₆ O ₇ ) - 7.30; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 17.30; SO ₄ ^2- - 0.25; the carrier is the rest; and has a specific surface area of 150 m ² / g, an average pore diameter of 15 nm and a pore volume of 0.3 cm ³ / g.

The IR spectra of the catalyst contain all characteristic bands typical of Co (C ₆ H ₆ O ₇ ) and H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], shown in Table 1. The binding energies determined from XPS spectra, as well as interatomic distances determined by EXAFS spectroscopy, confirm the presence of Co (C ₆ H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] and SO ₄ ² in the catalyst ^- in the above concentrations.

To compare the catalytic properties, the regenerated catalyst is tested in hydrotreating and fresh catalyst selected from the same batch before hydrotreating and regeneration. Fresh catalyst contains cobalt and molybdenum in terms of oxides, wt. %: CoO - 2.5; MoO ₃ - 12.0; the carrier is the rest; and has a specific surface area of 153 m ² / g, an average pore diameter of 15 nm and a pore volume of 0.31 cm ³ / g.

The process of hydrotreating diesel fuel is carried out at a volumetric feed rate of 2.5 h ^-1 , a hydrogen / feed ratio of 600, a temperature of 370 ° C, a hydrogen pressure of 3.8 MPa. As raw materials, straight-run diesel fuel is used, having a boiling range: 201-375 ° C; sulfur content: 0.355% wt .; the density of 0.861 g / cm ³ . The results of hydrotreatment of diesel fuel on regenerated and fresh catalysts are shown in table 2.

Examples 2-6 illustrate the proposed technical solution.

Example 2. Regenerate the same catalyst as in example 1.

Oxidative regeneration is carried out, for which a portion of the catalyst is placed at the inlet of an inclined flow-through drum furnace with electric heating, which has three heating zones and provides continuous mixing of the catalyst layer, air supply to the furnace is started in direct flow with a flow rate of 2500 h ^-1 . The temperature of the first zone changes from room temperature at the entrance to 650 ° C at the end of the zone, the temperature of the second zone is equal to 650 ° C throughout the zone, and the temperature of the third zone changes from 650 ° C to room temperature. The length of the zones and the rotational speed of the furnace drum are selected so that the catalyst is in the first zone for 2 hours, in the second zone for 0.5 hours, in the third zone for 1 hour. The catalyst is discharged from the furnace and placed in a hermetically sealed container.

Prepare a solution of 10 wt. % butyldiglycol in water. Next, a weighed portion of citric acid is dissolved in the resulting solution to obtain a solution having a citric acid concentration of 2.0 mol / L. A sample of 20 g of catalyst after oxidative regeneration in a flask that excludes evaporation of water is impregnated with 8 ml of a solution of citric acid in a mixture of water and butyldiglycol, the flask is fixed on a rotary device and placed in a bath heated to 90 ° C, with constant rotation, providing mixing of the catalyst, withstand 60 minutes Next, the catalyst is transferred to a Petri dish, which is placed in an oven heated to 120 ° C and dried at this temperature for 6 hours. Before determining the texture characteristics, the catalyst is heated in air for 2 hours at 500 ° C.

The resulting catalyst contains, by weight. %: Co (C ₆ H ₆ O ₇ ) - 5.6; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 10.5; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - 4.3; SO ₄ ^2- - 2,30; the carrier is the rest; and has a specific surface area of 150 m ² / g, an average pore diameter of 15 nm and a pore volume of 0.3 cm ³ / g. The catalyst carrier contains additives in a total amount of 5.0 wt. % - 4.0% Si and 1.0% R.

The IR spectra of the catalyst contain all characteristic bands typical of Co (C ₆ H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ], shown in Table 1. The binding energies and peak intensities determined from the XPS spectra, as well as the interatomic distances determined by EXAFS spectroscopy, confirm the presence of Co (C ₆ H ₆ O ₇ ), H ₄ in the catalyst [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] and SO ₄ ^2- in the above concentrations.

Hydrotreating of diesel fuel is carried out analogously to example 1.

The results of hydrotreating diesel fuel on a regenerated catalyst are shown in table 2.

Example 3. Regenerate the same catalyst as in examples 1 and 2.

Oxidative regeneration is carried out, for which 300 cm ^{3 of} deactivated catalyst is placed on a stainless steel mesh pan having a length and width of 100 mm. The height of the catalyst layer is 30 mm. The pallet is placed in a muffle furnace and serves air with a flow rate of 0.15 m ³ / hour. The catalyst is calcined according to the following program — warming from room temperature to 650 ° C for 2 hours, calcining at 650 ° C for 2 hours, cooling to room temperature for 2 hours. The catalyst is unloaded from the furnace and placed in a hermetically sealed container.

Prepare a solution of 20 wt. % butyldiglycol in water. Then, in the resulting solution, a weighed portion of citric acid is dissolved to obtain a solution having a concentration of 1.9 mol / L in citric acid. A sample of 20 g of catalyst after oxidative regeneration in a flask that excludes evaporation of water is impregnated with 8 ml of a solution of citric acid in a mixture of water and butyldiglycol, the flask is fixed on a rotary device and placed in a bath heated to 60 ° C, with constant rotation, providing mixing of the catalyst, incubated for 20 minutes The catalyst is then transferred to a Petri dish, which is placed in an oven heated to 100 ° C and dried at this temperature for 2 hours. Before determining the texture characteristics, the catalyst is heated in air for 2 hours at 500 ° C.

The resulting catalyst contains, by weight. %: Co (C ₆ H ₆ O ₇ ) - 5.1; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 7.5; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - 7.1; SO ₄ ^2- - 1,50; the carrier is the rest; and has a specific surface area of 150 m ² / g, an average pore diameter of 15 nm and a pore volume of 0.3 cm ³ / g. The catalyst carrier contains additives in a total amount of 5.0 wt. % - 4.0% Si and 1.0% R.

The IR spectra of the catalyst contain all characteristic bands typical of Co (C ₆ H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ], shown in Table 1. The binding energies and peak intensities determined from the XPS spectra, as well as the interatomic distances determined by EXAFS spectroscopy, confirm the presence of Co (C ₆ H ₆ O ₇ ), H ₄ in the catalyst [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] and SO ₄ ^2- in the above concentrations.

Hydrotreating diesel fuel is carried out analogously to example 1. The results of hydrotreating diesel fuel on a regenerated catalyst are shown in table 2.

Example 4

The catalyst used in the hydrotreatment of diesel fuel is regenerated. The deactivated catalyst contains, by weight. %: C - 8.0; S - 8.4; Co - 2.7; Mo - 9.4; the carrier is the rest. The catalyst has a specific surface area of 170 m ² / g, an average pore diameter of 8.5 nm and a pore volume of 0.39 cm ³ / g. The catalyst carrier contains modifying additives in a total amount of 2.4 wt. % - 2.0% La, 0.2% Mg and 0.2% F.

Oxidative regeneration is carried out, for which a portion of the catalyst is placed at the inlet of an inclined flow-through drum furnace with electric heating, which has three heating zones and provides continuous mixing of the catalyst layer, air supply to the furnace is started in direct flow with a flow rate of 1500 h ^-1 . The temperature of the first zone varies from room temperature at the entrance to 550 ° C at the end of the zone, the temperature of the second zone is equal to 550 ° C throughout the zone, and the temperature of the third zone changes from 550 ° C to room temperature. The length of the zones and the rotational speed of the drum of the furnace are selected so that the catalyst is in each zone for 2 hours. The catalyst is unloaded from the furnace and placed in a hermetically sealed container.

Prepare a solution of 20 wt. % butyldiglycol in water. Next, in the resulting solution, a weighed portion of citric acid is dissolved to obtain a solution having a concentration of 2.5 mol / L in citric acid. A sample of 20 g of catalyst after oxidative regeneration in a flask that excludes evaporation of water is impregnated with 11 ml of a solution of citric acid in a mixture of water and butyldiglycol, the flask is fixed on a rotary device and placed in a bath heated to 80 ° C, with constant rotation, providing mixing of the catalyst, stand 40 minutes Next, the catalyst is transferred to a Petri dish, which is placed in an oven heated to 220 ° C and dried at this temperature for 2 hours. Before determining the texture characteristics, the catalyst is heated in air for 2 hours at 500 ° C.

The resulting catalyst contains, by weight. %: Co (C ₆ H ₆ O ₇ ) - 10.17; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 7.85; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - 14.3; SO ₄ ^2- - 0.5; the carrier is the rest; and has a specific surface area of 240 m ² / g, an average pore diameter of 9.9 nm and a pore volume of 0.55 cm ³ / g. The catalyst carrier contains additives in a total amount of 2.4 wt. % - 2.0% La, 0.2% Mg and 0.2% F.

The IR spectra of the catalyst contain all characteristic bands typical of Co (C ₆ H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ], shown in Table 1. The binding energies and peak intensities determined from the XPS spectra, as well as the interatomic distances determined by EXAFS spectroscopy, confirm the presence of Co (C ₆ H ₆ O ₇ ), H ₄ in the catalyst [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] and SO ₄ ^2- in the above concentrations. To compare the catalytic properties, a fresh catalyst selected from the same batch is hydrotreated before being hydrotreated and regenerated. The fresh catalyst used to compare the catalytic properties contains cobalt and molybdenum in terms of oxides, wt. %: CoO - 4.1; MoO ₃ - 16.8; the carrier is the rest; and has a specific surface area of 240 m ² / g, an average pore diameter of 10 nm and a pore volume of 0.54 cm ³ / g.

The process of hydrotreating diesel fuel is carried out at a volumetric feed rate of 1 hour ^-1 , a hydrogen / feed ratio of 300, a temperature of 340 ° C, a hydrogen pressure of 3.0 MPa. As raw materials, straight-run diesel fuel is used, having a boiling range: 201-375 ° C; sulfur content: 0.355% wt .; the density of 0.861 g / cm ³ .

The results of hydrotreating diesel fuel on a regenerated catalyst are shown in table 2.

Example 5. Regenerate the same catalyst as in example 4.

Oxidative regeneration is carried out, for which 100 cm ^{3 of} deactivated catalyst are placed on a stainless steel mesh pan having a length and width of 100 mm. The height of the catalyst layer is 10 mm. The pallet is placed in a muffle furnace and serves air with a flow rate of 0.2 m ³ / hour. The catalyst is calcined according to the following program — warming from room temperature to 500 ° C for 2 hours, calcining at 500 ° C for 2 hours, cooling to room temperature for 2 hours. The catalyst is unloaded from the furnace and placed in a hermetically sealed container.

Prepare a solution of 10 wt. % butyldiglycol in water. Then, in the resulting solution, a weighed portion of citric acid is dissolved to obtain a solution having a concentration of 2.1 mol / L in citric acid. A sample of 20 g of catalyst after oxidative regeneration in a flask that excludes evaporation of water is impregnated with 11 ml of a solution of citric acid in a mixture of water and butyldiglycol, the flask is fixed on a rotary device and placed in a bath heated to 90 ° C, with constant rotation, providing mixing of the catalyst, withstand 60 minutes Next, the catalyst is transferred to a Petri dish, which is placed in an oven heated to 120 ° C and dried at this temperature for 6 hours. Before determining the texture characteristics, the catalyst is heated in air for 2 hours at 500 ° C.

The resulting catalyst contains, by weight. %: Co (C ₆ H ₆ O ₇ ) - 11.4; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 15.0; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - 9.1; SO ₄ ^2- - 0.6; the carrier is the rest; and has a specific surface area of 240 m ² / g, an average pore diameter of 9 nm and a pore volume of 0.6 cm ³ / g. The catalyst carrier contains additives in a total amount of 2.4 wt. % - 2.0% La, 0.2% Mg and 0.2% F.

The process of hydrotreating diesel fuel is carried out at a volumetric feed rate of 2.5 hours ^-1 , a hydrogen / feed ratio of 600 nm ³ N ₂ / m ^{3 of} feedstock, a temperature of 390 ° C, a hydrogen pressure of 9.0 MPa. As raw materials use straight-run diesel fuel having a boiling range: 180-365 ° C; sulfur content: 1.0% wt .; density 0.85 g / cm ³ .

The results of hydrotreatment of diesel fuel on regenerated and fresh catalysts are shown in table 2.

Example 6

The catalyst used in the hydrotreatment of diesel fuel is regenerated. The deactivated catalyst contains, by weight. %: C - 13.0; S - 13.1; Co - 4.0; Mo - 11.8; the carrier is the rest. The catalyst has a specific surface area of 240 m ² / g, an average pore diameter of 5 nm and a pore volume of 0.6 cm ³ / g. The catalyst carrier contains modifying additives in a total amount of 2.0 wt. % - 1.5% B; 0.2% Fe; 0.1% Ti and 0.1% Zr.

Oxidative regeneration is carried out, for which 50 cm ^{3 of} deactivated catalyst are placed on a stainless steel mesh tray having a length and width of 100 mm. The height of the catalyst layer is 5 mm. The pallet is placed in a muffle furnace and serves air with a flow rate of 0.2 m ³ / hour. The catalyst is calcined according to the following program — warming from room temperature to 550 ° C for 2 hours, calcining at 550 ° C for 2 hours, cooling to room temperature for 2 hours. The catalyst is discharged from the furnace and placed in a hermetically sealed container.

Prepare a solution of 15 wt. % butyldiglycol in water. Next, in the resulting solution, a weighed portion of citric acid is dissolved to obtain a solution having a concentration of 1.3 mol / L in citric acid. A sample of 20 g of catalyst after oxidative regeneration in a flask that excludes evaporation of water is impregnated with 16 ml of a solution of citric acid in a mixture of water and butyldiglycol, the flask is fixed on a rotary device and placed in a bath heated to 80 ° C, with constant rotation, providing mixing of the catalyst, stand 40 minutes Next, the catalyst is transferred to a Petri dish, which is placed in an oven heated to 150 ° C and dried at this temperature for 4 hours. Before determining the texture characteristics, the catalyst is heated in air for 2 hours at 500 ° C.

The resulting catalyst contains, by weight. %: Co (C ₆ H ₆ O ₇ ) - 18.0; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 13.1; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - 19.0; SO ₄ ^2- - 0.8; the carrier is the rest; and has a specific surface area of 280 m ² / g, an average pore diameter of 6 nm and a pore volume of 0.8 cm ³ / g. The catalyst carrier contains modifying additives in a total amount of 2.0 wt. % - 1.5% B; 0.2% Fe; 0.1% Ti and 0.1% Zr.

To compare the catalytic properties, a fresh catalyst selected from the same batch is hydrotreated before being hydrotreated and regenerated. The fresh catalyst used to compare the catalytic properties contains cobalt and molybdenum in terms of oxides, wt. %: CoO - 6.8; MoO ₃ - 24.0; the carrier is the rest; and has a specific surface area of 280 m ² / g, an average pore diameter of 6 nm and a pore volume of 0.8 cm ³ / g.

The process of hydrotreating diesel fuel is carried out analogously to example 5. The results of hydrotreating diesel fuel on regenerated and fresh catalysts are shown in table 2.

From the results of diesel hydrotreatment, shown in table 2, it follows that the resulting regenerated catalysts provide a degree of desulfurization of diesel fuel of at least 99.8%, have an activity of more than 100% of the activity of fresh catalysts. Accordingly, the inventive catalysts are suitable for the production of hydrotreated diesel fuels, according to the sulfur content corresponding to the EURO-5 standard.

Claims (3)

1. A regenerated hydrocarbon hydrotreating catalyst having a pore volume of 0.3-0.8 ml / g, a specific surface area of 150-280 m ² / g, an average pore diameter of 6-15 nm, including molybdenum, cobalt, sulfur and a carrier, characterized in that the molybdenum and cobalt are contained in the catalyst in the form of a mixture of complex compounds Co (C ₆ H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ], sulfur is contained in the form of the sulfate anion SO ₄ ^2- , in the following concentrations, wt. %: Co (C ₆ H ₆ O ₇ ) - 5.1-18.0; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] - 7.5-15.0; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - 4.3-19.0; SO ₄ ^2- - 0.5-2.30; the carrier is the rest. 2. The regenerated catalyst according to claim 1, characterized in that the cobalt citrates Co (C ₆ H ₆ O ₇ ) can be coordinated to molybdenum citrate H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ] and to 6 molybdocobaltate H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ]. 3. The regenerated catalyst according to claim 1, characterized in that the catalyst support is alumina Al ₂ O ₃ containing at least one component selected from the series: Fe, Si, P, B, Ti, Zr, F, Mg, La, with a total concentration of additional components in the carrier of 0.1-5.0 wt. %