RU2622040C1 - Method of diesel fuel hydrocleaning - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of hydrotreating diesel fuel at a temperature of 340-390°C, pressure 3-9 MPa, volumetric consumption of raw materials 1.0-2.5 h^-1, volume ratio hydrogen/raw materials 300-600 m³/m³ in the presence of a regenerated catalyst having 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 is described. 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_; carrier ^- the rest. Cobalt citrates can be coordinated to molybdenum citrate H₄[Mo₄(C₆H₅O₇)₂O₁₁] and to 6-molybdocobaltate H₃[Co(OH)₆Mo₆O₁₈].

EFFECT: invention makes it possible to produce hydrotreated diesel fuels containing not more than 10 ppm of sulfur in the presence of regenerated catalysts.

3 cl, 2 tbl, 6 ex

Description

The invention relates to methods for hydrotreating diesel fuel based on the use of regenerated catalysts.

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 undergo regeneration, most often based on the oxidative removal of carbon deposits and restoring activity by 90%. However, for the repeated hydrotreatment process to produce EURO-5 diesel fuels, such a restoration of activity is not enough.

In this regard, it is necessary to develop methods for hydrotreating to produce diesel fuel containing not more than 10 ppm sulfur, based on the use of regenerated catalysts, the activity of which is restored by 99% or more.

Known methods of hydrotreating based on the use of regenerated catalysts [US No. 7087546, B0J 20/34; EP No. 1418002 A2, B01J 23/85, C10G 45/08], which are obtained by impregnation of calcined catalysts 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 for hydrotreating on regenerated catalysts is described, the activity of which is restored 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 of the additive per mole of active metals in the catalyst, drying of the catalysts at 120 for 2 hours and subsequent calcination at 450 ° C.

A known method of hydrotreating proposed in [RF No. 2351634, C10G 45/08, B01J 37/02,], according to which the hydrocarbon feed is contacted with a regenerated catalyst containing a metal oxide of group VIII and a metal oxide of group VI, additionally containing 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 of the weight of the catalyst in an amount less than 5 wt. %

A common drawback for the above hydrotreatment methods is the insufficiently high activity of the catalysts used, due to their non-optimal, complex and unidentifiable chemical composition, which is the result of the absence of targeted synthesis of compounds with high catalytic activity in the activation process.

The closest in its technical essence and the achieved effect to the claimed method of hydrotreatment of diesel fuel is the method proposed in [RF No. 2484896, B01J 23/94, C10G 45/08, B01J 23/88, B01J 21/00, 06/20/2013], in accordance with which the hydrotreating of hydrocarbon feeds is carried out at a temperature of 320-400 ° C, a pressure of 0.5-10 MPa, a flow rate of feedstock of 0.5-5 h ^-1 , a volume ratio of hydrogen / feedstock of 100-1000 m ³ / m ³ in the presence of the regenerated catalyst comprising molybdenum and cobalt in the form citrate complexes of Co (C ₆ H ₆ O _7), H ₄ [Mo ₄ (C ₆ H ₅ O _{7) 2} O _11], and sulfur form of sulfate anion SO ₄ ^2- in the following concentrations by mass. %: 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; and 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, regenerated by the claimed method.

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

The invention solves the problem of creating an improved method for hydrotreating diesel fuel, characterized by a low sulfur content in the resulting diesel fuel, achieved through the use of a regenerated catalyst.

The problem is solved by the method of hydrotreating diesel fuel at a temperature of 340-390 ° C, a pressure of 3-9 MPa, a volumetric flow rate of 1.0-2.5 h ^-1 , a volumetric ratio of hydrogen / raw material 300-600 nm ³ H ₂ / m ³ raw materials in the presence of a regenerated 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 a carrier, molybdenum, cobalt, sulfur in the form mixtures 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 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 ]. 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 main distinguishing feature of the proposed diesel hydrotreatment process is that hydrotreating is carried out in the presence of a regenerated catalyst comprising molybdenum, cobalt, sulfur and a carrier, while 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 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 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 is also that hydrotreating is carried out in the presence of a regenerated catalyst at a temperature of 340-390 ° C, a pressure of 3-9 MPa, a volumetric flow rate of 1.0-2.5 h ^-1 , a volumetric ratio of hydrogen / raw material nm ³ H ₂ / m ³ raw materials.

The technical effect of the proposed method for hydrotreating diesel fuel consists of the following components:

1. The chemical composition of the reactivated catalyst used for hydrotreating and its texture provide maximum activity in the target reactions occurring during hydrotreating 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. Hydrotreating diesel fuel in the presence of a regenerated 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, provides good access to raw materials to be converted to active component and contributes to the achievement of low sulfur content in products.

3. The claimed conditions for the process of hydrotreating diesel fuel in the presence of a regenerated catalyst allow to obtain diesel fuel with a sulfur content of not more than 10 ppm.

Description of the proposed technical solution

Hydrotreating of diesel fuel is carried out at a temperature of 340-390 ° C, a pressure of 3-9 MPa, a volumetric flow rate of 1.0-2.5 h ^-1 , a volumetric ratio of hydrogen / raw material 300-600 nm ³ H ₂ / m ³ raw materials in the presence of regenerated catalysts. 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 alumina 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. %

Deactivated catalysts are 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 regulated, on the one hand, by the temperature of the heating elements of the furnace, and, on the other hand, by the air flow rate, which has two functions — it supplies the amount of oxygen necessary for the complete burning of carbon deposits and oxidation of surface metal sulfides, and also removes it from the catalyst layer the main amount of 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. Then, 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, and surface sulfate complexes in the catalyst 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].

The peaks corresponding to Co (C ₆ H ₆ O ₇ ) —Co2p3 / 2 = 782.0 eV, are present in the XPS spectra; 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 intensity of the peaks in the XPS spectra makes it possible to determine the concentration of each component in the catalyst.

H₄[Mo₄(C₆H₅O₇)₂O₁₁] - Mo-O=1,75 и

Mo-Mo=3,40 и

H₃[Co(OH)₆Mo₆O₁₈] - Mo-O=1,71; 1,95 и

For the 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 ) -

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

Mo-Mo = 3.40 and

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

As a result of the regeneration according to the above method, get catalysts 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.

For testing in hydrotreating, the catalysts are used in the form of extrudates with a cross section in the form of a trefoil or a 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 wt. % 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 with a rate of temperature rise of 25 ° C / h;

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

- increase 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)

Hydrotreating of diesel fuel is carried out in the presence of a regenerated catalyst, which is regenerated according to the procedure described below.

First, the catalyst is regenerated, which was used for 24 months in the process of hydrotreating diesel fuel. 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% P.

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 / h. 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 the XPS spectra and the 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

The same catalyst was regenerated 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 unloaded 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 the catalyst after oxidative regeneration in a flask that excludes water evaporation 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, which ensures mixing of the catalyst, withstand 60 minutes The catalyst is then 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% P.

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 [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

The same catalyst is regenerated 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 tray is placed in a muffle furnace and air is supplied at a flow rate of 0.15 m ³ / h. 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 water evaporation 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, which provides 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% P.

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 [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 hole 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 changes 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 the catalyst after oxidative regeneration in a flask that excludes water evaporation 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. The catalyst is then 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 [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 to be tested before the hydrotreatment and regeneration process. 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 h ^-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

The same catalyst was regenerated 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 / h. 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, which ensures mixing of the catalyst, withstand 60 minutes. The catalyst is then 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 h ^-1 , a hydrogen / feed ratio of 600 nm ³ H ₂ / m ^{3 of} feedstock, a temperature of 390 ° C, a hydrogen pressure of 9.0 MPa. As raw materials, straight-run diesel fuel is used, 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 is placed on a stainless steel mesh pan 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 The catalyst is then 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; 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 to be tested before the hydrotreatment and regeneration process. 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 shown in table 2, it follows that the inventive method of hydrotreating diesel fuel using regenerated catalysts having an activity of 100% or more of the activity of fresh catalysts, allows to obtain hydrotreated diesel fuels, sulfur content corresponding to the EURO-5 standard.

Claims (3)

1. The method of hydrotreating diesel fuel in the presence of a heterogeneous catalyst comprising molybdenum, cobalt, sulfur and a carrier, characterized in that the hydrotreating is carried out in the presence of a regenerated catalyst having a pore volume of 0.3-0.8 ml / g, specific surface area 150-280 m ² / g, average pore diameter of 6-15 nm, including molybdenum, cobalt, sulfur and a carrier in which 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 hydrotreating method according to claim 1, characterized in that 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 hydrotreating method according to claim 1, characterized in that the hydrotreating is carried out at a temperature of 340-390 ° C, a pressure of 3-9 MPa, a volumetric flow rate of 1.0-2.5 h ^-1 , a volumetric ratio of hydrogen / raw material 300- 600 m ³ / m ³ .