EA037668B1 - Regenerated hydrotreating catalyst - Google Patents

Abstract

The invention relates to regenerated hydrotreating catalysts intended for the production of low-sulphur diesel fuel. The invention solves the problem of providing an improved regenerated hydrotreating catalyst. A regenerated hydrotreating catalyst is described which has a pore volume of 0.3-0.8 ml/g, a specific surface area of 150-280 m2/g and an average pore diameter of 6-15 nm, and which contains molybdenum, cobalt, sulphur and a carrier, the molybdenum and cobalt being present in the catalyst in the form of a mixture of complex compounds Co(C6H6O7), H4[Mo4(C6H5O7)2O11], H3[Co(OH)6Mo6O18], the sulphur being present in the form of a sulphate anion SO42-, 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; SO42- - 0.5-2.30; with the remainder being the carrier, wherein cobalt citrates can be coordinated to molybdenum citrate H4[Mo4(C6H5O7)2O11] and to 6-molybdocobaltate H3[Co(OH)6Mo6O18]. The technical result is that the invention makes it possible to produce regenerated catalysts the activity of which, in the hydrotreatment of a diesel fuel, is more than or equal to 100% of the activity of fresh catalysts.

Description

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

Currently, the Russian oil refining industry produces diesel fuels with a sulfur content of no more than 10 ppm that meet EBPO-5 standards. The production of such low-sulfur fuels is achieved by deep hydrotreating of straight-run or mixed diesel fractions only with the use of highly active catalysts providing a degree of hydrodesulfurization of at least 99%. This degree of desulfurization is achievable only with modern catalysts of the latest generation.

During operation, catalysts are inevitably deactivated and need to be regenerated. For regeneration, oxidative removal of carbon deposits is used (the main reason for deactivation), however, oxidative regeneration of modern highly active hydrotreating catalysts makes it possible to restore their activity by no more than 90%, which is not enough for reuse of catalysts in the processes of obtaining low-sulfur diesel fuels EBPO-5. In this regard, it is necessary to develop regenerated deep hydrotreating catalysts with an activity of at least 99% of the activity of fresh catalysts.

Many different methods have been described for the regeneration of deactivated hydrotreating catalysts, but their common drawback is the insufficiently complete recovery of activity.

Known methods of extra-reactor regeneration are 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 unloaded from the reactor and regenerated in one of the following ways:

1) regeneration in a tunnel oven divided into several temperature zones. A thin bed of catalyst is fed onto a first fine-mesh belt that moves at high speed. This is where most of the coke deposits are 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 the catalyst bed [C. Vuitel, NPRA Ann. Meeting, Oct. 8-10, 1997.];

2) regeneration in a rotary inclined kiln, in which there are ribs and rings that form the catalyst bed. Temperature control and excess heat removal 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 sequentially located fluidized bed reactors. Stirring of the catalyst bed is provided by supplying air to the bottom of the reactors. Temperature control is carried out by the flow and temperature of the air, the temperature in the jackets of the reactor and the level of the 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 the regenerated catalysts, after oxidative regeneration, they are treated with various activating agents.

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 different molar ratios and then dried at different temperatures. Compounds containing an amino group (-NH2), a hydroxo group (-OH), a carboxyl group (-COOH) can also be used as an organic additive.

Thus, WO 2005070542 A1, B0J 38/48 describes a method for restoring the activity of catalysts by treating them with ethylenediaminetetraacetic, nitrilotriacetic, hydroxyethylenediaminetriacetic 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 additive per mole of active metals in the catalyst, the catalyst is dried at 120 ° C for 2 hours and calcination is carried out at 450 ° C.

Known catalyst, regeneration method and hydrotreating method, proposed in the Russian Federation No. 2351634, C10G 45/08, B01J 37/02, according to which the regenerated catalyst contains a metal oxide of group VIII and a metal oxide of group VI, additionally contains an acid and an organic additive, which has a temperature boiling in the range of 80-500 ° C and solubility in water of at least 5 g / l, while the catalyst contains a crystalline fraction, expressed as the weight of the fraction of crystalline compounds of metals of group VI and group VIII relative to the total weight of the catalyst, in an amount of less than 5 wt. %. The known method of regeneration includes contacting the catalyst with an acid and an organic additive, which has a boiling point in the range of 80-500 ° C and a water solubility of at least 5 g / l, optionally followed by drying under such conditions that at least 50 wt. % of the additive remains in the catalyst. A known hydrotreating method consists in contacting a hydrocarbon feedstock with a catalyst regenerated by the above-described method.

A common disadvantage for the abovementioned regenerated catalysts is their insufficiently high activity due to the suboptimal, complex and unidentifiable chemical composition of the obtained catalysts.

The closest in its technical essence and the achieved effect to the claimed regenerated catalyst is the catalyst proposed in the Russian Federation No. 2484896, B01J 23/94,

C10G 45/08, 20.06.2013.

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 SO4 ^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 the cobalt citrates can be coordinated to the 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 suboptimal chemical composition.

The 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 are then converted into the most active component of hydrotreating catalysts;

2) optimal textural characteristics of catalysts, providing good access of sulfur-containing molecules of raw materials to the active component, which leads to the production of petroleum products with a low sulfur content;

3) the presence in the catalyst of a carrier based on aluminum oxide Al ₂ O ₃ containing additional components selected from the range of Fe, Si, P, B, Ti, Zr, F, Mg, La in the claimed concentrations, as contributing to the further selective production of sulfide active component and promoting the activity of catalysts in target hydrotreating reactions;

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

The problem is solved by a regenerated catalyst for hydrotreating hydrocarbon feedstock, 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 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 the cobalt citrates Co (C6H6O7) can be coordinated to molybdenum citrate H4 [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ On] and to 6-molybdocobaltate H ₃ [Co (OH) 6Mo ₆ Oi8].

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 (C6H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) 6Mo ₆ O ₁₈ ], sulfur - 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 Co (C6H 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 O1 8].

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

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

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

2) the presence of sulfur in the catalyst 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 of a carrier containing additional components in the claimed concentrations ensures the further production of an active component with an optimal structure and morphology;

4) the claimed textural characteristics of the obtained catalyst provide good access of the raw material molecules to be converted to the active component;

5) carrying out hydrotreating of diesel fuel in the presence of a catalyst of the claimed chemical composition makes it possible to obtain diesel fuel containing no more than 10 ppm sulfur at low

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Description of the proposed technical solution

For regeneration, catalysts are used that have been deactivated during their operation in the hydrotreating of various hydrocarbon feedstocks. Typically, the catalysts contain, wt%: 5.0-25.0 carbon; 5.0-15.0 sulfur; 0.1-2.5 nitrogen; 8.0-16.0 Mo; 2.0-5.5 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.%.

The deactivated catalyst is calcined in air so that the temperature at any point in the catalyst bed does not exceed 650 ° C. For this, either a thin layer of catalyst 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 calcination is carried out in a flow-through tube furnace with continuous stirring of the catalyst layer.

The bed temperature is controlled, 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 performs two functions - it supplies the amount of oxygen required for the complete burnout of carbon deposits and oxidation of surface metal sulfides, and also removes it from the bed. the catalyst is the main amount of heat released during combustion. Since in this case the combustion of carbonaceous deposits occurs in an excess of oxygen, the graphitization of coke does not occur and all deposits are completely burned out at a relatively low temperature.

The oxidative regeneration procedure is carried out in one of two ways:

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

2) a weighed amount of catalyst is placed at the inlet of an inclined drum furnace with electric heating, which has three heating zones, and air is supplied to the furnace at a rate of 1500-2500 h ^-1 . The temperature of the first zone changes from room temperature at the inlet to no more than 650 ° C at the end of the zone, the temperature of the second zone is equal throughout the entire 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 in such a way that the catalyst is in the first zone for 1-2 hours, in the second zone for 0.5-4 hours, in the third zone for 1-2 hours.

These calcination conditions simulate well the conditions of industrial belt and drum furnaces and provide complete removal of carbonaceous deposits in the absence of catalyst sintering.

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 ,five; Mo - 10.0-16.0; S - 0.2-0.8; C - no more than 0.2 wt%.

Next, prepare a citric acid solution 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 sample of the calcined catalyst is impregnated with the resulting solution. Impregnation is carried out according to moisture capacity, then the wet catalyst is stirred in a rotary evaporator flask without air supply at a temperature of 60-90 ° C for 20-60 minutes under conditions that preclude 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 complexes of Co, Mo and surface sulfates in the catalyst is confirmed by a combination of the following research methods: mass elemental analysis of Co, Mo, C, H, S; IR-; XPS 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) 6Mo ₆ O ₁₈ ] (Table 1).

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Table 1

Characteristic bands of complexes in the composition of catalysts

Complex compound Absorption bands, cm ¹ Co (C ₆ H ₆ O ₇ ) 3450, 1615, 1577, 1429, 1380, 1290, 1265, 1160, 1080,1060, 950, 910, 845 H4 [MO4 (SbN ₅ O ₇ ) 2O11] 1720, 1660, 1620, 1595, 1560, 1430, 1410; 950, 920, 900, 890, 870, 850, 820, 800,740, 730, 690, 650, 620 H ₃ [Co (OH) ₆ Mo ₆ O1 ₈ ] 1625,1092, 952,902,647,583,446,388, 324, 286

The assignments of bands in the IR spectra are made in accordance with S.M. Tsimbler, L.L. Shevchenko, V.V. Grigorieva 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 XPS spectra contain peaks corresponding to Co (C ₆ H ₆ O ₇ ) - Co2p3 / 2 = 782.0 eV; H4 [Mo4 (C6H ₃ O7) 2O11] - Mo3d5 / 2 = 232.4 eV; Hs [Co (OH) 6Mo6O18] - Mo3d5 / 2 = 232.6 eV and Co2p3 / 2 = 781.6 eV with a Co ³⁺ satellite with a binding energy of 791.4 eV; SO ₄ ^2- - S2p = 169.3 eV. The assignments are made in accordance with V.I. Nefedov, X-ray electron spectroscopy of chemical compounds. M. Chemistry. 1984, 256 p. The intensity of the peaks in the XPS spectra will make it possible to determine the concentration of each component in the catalyst.

For the regenerated catalysts, on the curves of the radial distribution of atoms obtained by the Fourier transform of EXAFS spectra, the distances corresponding to Co (C6H6O7) - Co-O = 2.02 A were recorded; H4 [Mo4 (C6H ₃ O7) 2O _G ] - Mo — O = 1.75 and 1.95 A; Mo — Mo = 3.40 and 3.69 A; H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] - Mo — O = 1.71; 1.95 and 2.30 A; Mo-Mo = 3.32 A; Mo-Co = 3.69 A.

As a result of the regeneration according to the above method, catalysts are obtained having the claimed textural 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 SO4 ^2- , as well as the carrier in the claimed concentration ranges.

Next, diesel fuel is hydrotreated at a volumetric feed rate in the range of 1-2.5 h ' ¹ , a hydrogen / raw material ratio of 300-600 nm ³ H ₂ / m ^{3 of a} raw material, a temperature of 340-390 ° C, a hydrogen pressure of 3- 9 MPa.

Diesel fuel with a boiling range of 201-375 ° C is used as a raw material; sulfur content - 0.355 wt.%; density - 0.861 g / cm ³ ; or diesel fuel having a boiling range of 180-365 ° C; sulfur content - 1.0 wt.%; density - 0.85 g / cm ³ .

For testing in hydrotreating, catalysts are used in the form of extrudates with a trefoil or quatrefoil section with a circumscribed circle diameter of 1.3-1.6 mm and an average granule length of 3-6 mm.

The preliminary sulfiding of the catalysts is carried out directly in the hydrotreating reactor with a straight-run diesel fraction containing an additional 1.5 wt% of a sulfiding agent, dimethyl disulfide (DMDS), at a volumetric feed rate of the sulfiding mixture of 2 h ^-1 and a hydrogen / feed ratio of 300. Sulfidation includes several stages of catalyst drying in a hydrotreating reactor in a stream of hydrogen at 140 ° C for 2 h;

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

sulphiding mixture supply and temperature increase up to 240 ° C with a temperature rise rate of 25 ° C / h;

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

increasing the reactor temperature to 340 ° C with a temperature rise rate of 25 ° C / h; sulfiding at 340 ° C for 8 hours (high-temperature stage). The essence of the invention is illustrated by the following examples and table.

Example 1. According to the known solution.

The catalyst, which has been used for 24 months in the process of diesel fuel hydrotreating, is regenerated. The deactivated catalyst contains, wt%: C - 11.1; S 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 support contains modifying additives in a total amount of 5.0 wt% - 4.0% Si and 1.0% P.

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Oxidative regeneration is carried out, for which 100 g of the deactivated catalyst is placed on a stainless steel mesh tray 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 air is supplied at a rate of 0.25 m ³ / h. The catalyst is calcined according to the following program: heating from room temperature to 550 ° C for 2 h, calcination at 550 ° C for 4 h, and cooling to room temperature for 2 h.

The catalyst after oxidative regeneration contains, wt%: 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. After oxidative regeneration, a 20 g weighed portion of the catalyst is impregnated by moisture capacity with 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 textural characteristics, the catalyst is heated in air for 2 h at 500 ° C.

The resulting catalyst contains, wt%: Co (C ₆ H ₆ O7) -7.30; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ Ots] - 17.30; SO4 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 for Co (C6H 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 the XPS spectra, as well as the interatomic distances determined by EXAFS spectroscopy, confirm the presence of Co (C6H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ Ots] in the catalyst and SO ₄ ^2- in the above concentrations.

To compare the catalytic properties, testing is carried out in the hydrotreating of the regenerated catalyst and fresh catalyst taken from the same batch, prior to the hydrotreating and regeneration process. 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, and a hydrogen pressure of 3.8 MPa. The raw material used is straight-run diesel fuel having a boiling range of 201-375 ° C, a sulfur content of 0.355 wt%, a density of 0.861 g / cm ³ . The results of hydrotreating 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 is regenerated as in example 1.

Oxidative regeneration is carried out, for which a sample of the catalyst is placed at the inlet of an inclined continuous-flow drum furnace with electric heating, which has three heating zones and provides continuous mixing of the catalyst layer, air is supplied to the furnace in cocurrent flow at a rate of 2500 h ^-1 . The temperature of the first zone changes from room temperature at the inlet to 650 ° C at the end of the zone, the temperature of the second zone is equal throughout the entire zone - 650 ° C, 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 in such a way 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.

A solution of 10 wt.% Butyldiglycol in water is prepared. Further, 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 weighed portion of 20 g of the catalyst after oxidative regeneration in a flask, excluding the evaporation of water, is impregnated with 8 ml of a citric acid solution 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, ensuring the stirring of the catalyst, stand for 60 minutes. Next, the catalyst is transferred into a Petri dish, which is placed in an oven heated to 120 ° C, and dried at this temperature for 6 h. Before determining the textural characteristics, the catalyst is heated in air for 2 h at 500 ° C.

The resulting catalyst contains, wt%: Co (C6H 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 Oi8] - 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 support 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 for Co (C6H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) 6Mo ₆ O ₁₈ ] , given 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 (C6H 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 3. The same catalyst is regenerated as in examples 1 and 2.

Oxidative regeneration is carried out, for which 300 cm ^{3 of the} deactivated catalyst is placed on a stainless steel mesh tray having a length and width of 100 mm. In this case, the height of the catalyst bed is 30 mm. The pallet is placed in a muffle furnace and air is supplied at a rate of 0.15 m ³ / h. The catalyst is calcined according to the following program: heating from room temperature to 650 ° C for 2 h, calcination at 650 ° C for 2 h, cooling to room temperature for 2 h. The catalyst is unloaded from the furnace and placed in a sealed container.

A solution of 20 wt% butyldiglycol in water is prepared. Next, a weighed portion of citric acid is dissolved in the resulting solution to obtain a solution having a citric acid concentration of 1.9 mol / l. A weighed portion of 20 g of catalyst after oxidative regeneration in a flask, excluding the evaporation of water, is impregnated with 8 ml of citric acid solution 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, ensuring the stirring of the catalyst, stand for 20 minutes. Next, the catalyst is transferred into a Petri dish, which is placed in an oven heated to 100 ° C, and dried at this temperature for 2 h. Before determining the textural characteristics, the catalyst is heated in air for 2 h at 500 ° C.

The resulting catalyst contains, wt%: Co (C ₆ H ₆ O7) - 5.1; H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ Oii] - 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 support 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 for Co (C6H ₆ O ₇ ), H ₄ [Mo ₄ (C ₆ H ₅ O ₇ ) ₂ O ₁₁ ], H ₃ [Co (OH) 6Mo ₆ O ₁₈ ] , given 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 On], H ₃ [Co (OH) ₆ Mo ₆ Oi8] 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 which was used in the process of diesel fuel hydrotreating is regenerated. The deactivated catalyst contains, wt%: 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 support 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 weighed portion of the catalyst is placed at the inlet of an inclined continuous-flow drum furnace with electric heating, which has three heating zones and provides continuous mixing of the catalyst layer, and air is fed into the furnace by direct flow at a rate of 1500 h ' ¹ . The temperature of the first zone changes from room temperature at the inlet to 550 ° C at the end of the zone, the temperature of the second zone is equal throughout the entire zone to 550 ° C, the temperature of the third zone changes from 550 ° C to room temperature. The length of the zones and the rotational speed of the furnace drum are selected in such a way that the catalyst is in each zone for 2 hours. The catalyst is unloaded from the furnace and placed in a hermetically sealed container.

A solution of 20 wt% butyldiglycol in water is prepared. Next, a weighed portion of citric acid is dissolved in the resulting solution to obtain a solution having a citric acid concentration of 2.5 mol / l. A weighed portion of 20 g of the catalyst after oxidative regeneration in a flask, excluding the evaporation of water, is impregnated with 11 ml of a citric acid solution 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, ensuring the stirring of the catalyst, stand for 40 minutes. Next, the catalyst is transferred into a Petri dish, which is placed in an oven heated to 220 ° C, and dried at this temperature for 2 h. Before determining the textural characteristics, the catalyst is heated in air for 2 h at 500 ° C.

The resulting catalyst contains, wt%: Co (C ₆ H ₆ O ₇ ) - 10.17; H ₄ [Mo ₄ (C6H ₅ O ₇ ) ₂ O _n ] - 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 support 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 About ₁₈ ], given 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 O11], H ₃ [Co (OH) ₆ Mo ₆ O ₁₈ ] and SO ₄ ^2- in the above concentrations.

To compare the catalytic properties, testing is carried out in the hydrotreating of a fresh catalyst taken from the same batch, prior to the hydrotreating 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, and a hydrogen pressure of 3.0 MPa. The raw material used is straight-run diesel fuel, which has a boiling range of 201-375 ° C, sulfur content

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0.355% wt., Density 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 is regenerated as in example 4.

Oxidative regeneration is carried out, for which 100 cm ^{3 of the} deactivated catalyst is placed on a stainless steel mesh tray having a length and width of 100 mm. In this case, the height of the catalyst bed is 10 mm. The pallet is placed in a muffle furnace and air is supplied at a rate of 0.2 m ³ / h. The catalyst is calcined according to the following program: heating from room temperature to 500 ° C for 2 h, calcination at 500 ° C for 2 h, cooling to room temperature for 2 h. The catalyst is unloaded from the furnace and placed in a sealed container.

A solution of 10 wt.% Butyldiglycol in water is prepared. Next, a weighed portion of citric acid is dissolved in the resulting solution to obtain a solution having a citric acid concentration of 2.1 mol / l. A weighed portion of 20 g of catalyst after oxidative regeneration in a flask, excluding the evaporation of water, is impregnated with 11 ml of citric acid solution 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, ensuring the stirring of the catalyst, stand for 60 minutes. Next, the catalyst is transferred into a Petri dish, which is placed in an oven heated to 120 ° C, and dried at this temperature for 6 h. Before determining the textural characteristics, the catalyst is heated in air for 2 h at 500 ° C.

The resulting catalyst contains, wt%: Co (C6H 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 support 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 / raw material ratio of 600 nm ³ H ₂ / m ^{3 of a} raw material, a temperature of 390 ° C, and a hydrogen pressure of 9.0 MPa. The raw material used is straight-run diesel fuel having a boiling range of 180-365 ° C; sulfur content 1.0 wt.%, density 0.85 g / cm ³ .

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

Example 6.

The catalyst which was used in the process of diesel fuel hydrotreating is regenerated. The deactivated catalyst contains, wt% 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 of the deactivated catalyst is placed on a stainless steel mesh tray having a length and width of 100 mm. The height of the catalyst bed is 5 mm. The pallet is placed in a muffle furnace and air is supplied at a rate of 0.2 m ³ / h. The catalyst is calcined according to the following program: heating from room temperature to 550 ° C for 2 hours; calcination at 550 ° C for 2 hours; cooling to room temperature for 2 hours. The catalyst is unloaded from the oven and placed in a sealed container.

A solution of 15 wt% butyldiglycol in water is prepared. Next, a weighed portion of citric acid is dissolved in the resulting solution to obtain a solution having a citric acid concentration of 1.3 mol / l. A weighed portion of 20 g of catalyst after oxidative regeneration in a flask, excluding the evaporation of water, is impregnated with 16 ml of citric acid solution 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, ensuring the stirring of the catalyst, stand for 40 minutes. Next, the catalyst is transferred into a Petri dish, which is placed in an oven heated to 150 ° C, and dried at this temperature for 4 h. Before determining the textural characteristics, the catalyst is heated in air for 2 h at 500 ° C.

The resulting catalyst contains, wt%: Co (C6H 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, testing is carried out in the hydrotreating of a fresh catalyst taken from the same batch, prior to the hydrotreating 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 support 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.

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table 2

Results of Hydrotreating Diesel Fuel on Regenerated and Fresh Catalysts

Catalyst Residual sulfur content in diesel fuel, ppm Desulfurization degree,% Recovery of activity,% Example 1, regenerated 39.0 98.90 99.8 Example 1 fresh 32.0 99.10 - Example 2, regenerated 5.3 99.85 100.7 Example 3, regenerated 3.6 99.90 100.8 Example 4 fresh 24.8 99.30 - Example 4, regenerated 7.1 99.80 100.3 Example 5 fresh fifty 99.50 - Example 5, regenerated 10 99.90 100.4 Example 6 fresh 70 99.30 - Example 6, regenerated 10 99.90 100.6

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

Claims (3)

CLAIM 1. Regenerated catalyst for hydrotreating hydrocarbon feedstock, having a pore volume of 0.30.8 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 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 (C6H ₆ O ₇ ) - 5.1-18.0; H4 [Mo4 (C6HsO7) 2Oii] 7.5-15.0; H ₃ [Co (OH) 6Mo6Oi ₈ ] - 4.3-19.0; SO4 ² - 0.5-2.30; the carrier is the rest. 2. The regenerated catalyst according to claim 1, wherein 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 H3 [Co (OH) 6Mo ₆ O1 ₈ ]. 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.%.