RU2724347C1 - Method of producing low-sulfur diesel fuel - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to a method consisting in conversion of mixed and straight-run diesel fractions with high sulfur content at temperature of 340–380 °C, pressure 3.5–8.0 MPa, mass flow rate of raw 1.0–2.5 h, volume ratio of hydrogen/feedstock 300–500 m/min the presence of a heterogeneous catalyst comprising, by wt%: [Co(HO)(CHO)][MoO(CHO)] – 7.7–32.0; Co[HPMoO] – 11.1–29.0; carrier – balance; carrier contains, wt%: silicon dioxide SiO– 2.0–20.0, aluminum borate AlBOwith structure of norbergite – 5.0–25.0, γ-AlOis the rest. Catalyst has specific surface area of 120–180 m/g, a pore volume of 0.30–0.50 cm/g, an average pore diameter of 7–12 nm and represents a particle cross section as a circle, a trefoil or quatrefoil with diameter of 1.0–1.6 mm and a length of circumference 20 mm.EFFECT: obtaining diesel fuel containing less than 10 ppm of sulfur during hydrofining of straight-run and mixed diesel fractions with high content of sulfur.1 cl, 2 dwg, 1 tbl, 7 ex

Description

The invention relates to catalytic methods for producing low-sulfur diesel fuels from straight-run and mixed diesel fractions with a high sulfur content.

Demand for deep hydrotreating catalysts is currently growing due to the tightening of existing environmental standards for diesel fuel quality in accordance with [GOST R 52368-2005 (EN 590: 2009). Diesel fuel EURO. Specifications]. In addition, there are trends in the involvement of heavier oil fractions in the processing and an increase in the proportion of sour crude oils in the processed raw materials. In recent years, the proportion of secondary fractions containing refractory sulfur compounds and nitrogen compounds, which inhibit the conversion of sulfur-containing compounds, has been constantly increasing in the raw materials of hydrotreatment plants. Accordingly, the conditions of the hydrotreating process are excessively stringent due to the low activity of the catalysts. For hydrotreating mixed diesel fractions on known catalysts with low activity, it is necessary to increase the starting temperature of the hydrotreating process, which leads to rapid deactivation of the catalysts.

In this regard, an extremely urgent task is the creation of new processes for producing low-sulfur diesel fuels based on the use of highly active domestic catalysts, which make it possible to further obtain motor fuels that meet the Euro-5 standard in sulfur content at the lowest possible starting temperature of the hydrotreating process. Existing hydrotreatment plants operate in a fairly narrow range of temperatures, flows, and pressures. So, for most Russian installations of deep hydrotreatment of diesel fuels, usually the pressure does not exceed 4.0 MPa, the consumption of raw materials is 1.0-2.5 h ^-1 , the volume ratio of hydrogen / raw materials is 300-500 nm ³ / m ³ . The starting temperature of the hydrotreating process cannot be chosen over a wide range and should be as low as possible, since the deactivation rate and the inter regeneration run of the catalyst depend on it. Thus, the main tool that allows you to change the amount of sulfur in the resulting products, without significant changes in the conditions of the hydrotreating process and reconstruction of plants, are the characteristics of the used catalysts, of which the most important is the catalytic activity.

There are various methods for hydrotreating diesel fuel, but the main disadvantage for them is the high residual sulfur content in the resulting products, due to the low activity of the used catalysts. Most often, the hydrodesulfurization of petroleum feeds is carried out in the presence of catalysts containing cobalt and molybdenum oxides supported on alumina.

Thus, a known method for producing low sulfur diesel fuel [RU 2100408, C10G 65/04, 12/27/1997], in which the hydrotreatment process is carried out in two stages with intermediate heating of the gas-oil mixture using an aluminum-nickel-molybdenum catalyst with a predominant pore radius in the first stage 9-12 nm, and in the second stage - aluminum-nickel-molybdenum (ASM) or aluminum-cobalt-molybdenum (AKM) catalyst with a predominant pore radius of 4-8 nm with a mass ratio of the catalysts of the first and second stages 1: (2-6 ) The process is carried out at temperatures of 250-350 ° C in the first stage and 320-380 ° C in the second stage. The method allows to increase the degree of hydrodesulfurization of the feedstock and to obtain diesel fuel with a sulfur content of less than 0.05 wt. % while increasing the yield of the target fraction 200-360 ° C.

A known method of producing low sulfur diesel fuel from hydrocarbons with a high sulfur content [RU 2312886, C10G45 / 08, 20.12.2007]. A method for producing diesel fuel is described, which consists in converting straight-run diesel fuel with a high sulfur content in the presence of a pre-sulfidized heterogeneous catalyst containing a group VIII metal and a group VIB metal deposited on aluminum oxide Al ₂ O ₃ having a pore volume of 0.3-0, 7 ml / g, specific surface area 200-350 m ² / g and average pore diameter 9-13 nm. The catalyst before the sulfidation stage contains the following components: cobalt compounds with a concentration, wt.%: 2.5-7.5 in terms of CoO, molybdenum compounds with a concentration of 12-25 in terms of MoO ₃ , citric acid compounds with a concentration of 15-35 in terms of citric acid, boron compounds of 0.5-3 in terms of B ₂ O ₃ , aluminum oxide Al ₂ O ₃ - the rest, while cobalt, molybdenum, citric acid and boron can be part of complex compounds of different stoichiometry. The process is carried out at a temperature of 320-370 ° C, a pressure of 0.5-10 MPa, a mass flow rate of raw materials of 0.5-5 h ^-1 , a volumetric ratio of hydrogen / raw material of 100-1000 m ³ / m ³ . EFFECT: obtaining diesel fuels with a sulfur content of less than 50 ppm.

A known method of hydrotreating diesel fractions [Smirnov V.K., Kapustin V.M., Gantsev V.A. // Chemistry and technology of fuels and oils. 2002. No3. C. 3], which consists in transmitting raw materials at 330-335 ° C, a pressure of 2.5-2.7 MPa, with a hydrogen-containing gas / feed ratio of 250-300 nm ³ / m ³ and a volumetric feed rate of 2.5-3 h ^-1 through a reactor filled with a mixture of catalysts RK-012 + TNK-2000 (AKM) + TNK-2003 (ASM). In this process, the residual sulfur content in the resulting diesel fraction is achieved at the level of 800-1200 ppm.

A known method of hydrodesulfurization of petroleum feedstocks [RU 2002124681, C10G 45/08, B01J 23/887, 05/10/2004], where the hydrotreating process is carried out at a temperature of 310-340 ° C, a pressure of 3.0-5.0 MPa, with a hydrogen / raw materials 300-500 nm ³ / m ³ and a bulk feed rate of 1.0-4.0 h ^-1 , using a catalyst containing cobalt oxide, molybdenum oxide and aluminum oxide, characterized in that it has a ratio components, wt.%: cobalt oxide 3.0-9.0, molybdenum oxide 10.0-24.0, aluminum oxide - the rest, specific surface area 160-250 m ² / g, mechanical crushing strength 0.6-0 8 kg / mm ² .

The known process of hydrotreating hydrocarbon raw materials [RU 2402380, B01J 21/02, C10G 45/08, 10.27.2010], which consists in the conversion of petroleum distillates with a high sulfur content at a temperature of 320-400 ° C, a pressure of 0.5-10 MPa, weight the feed rate of 0.5-5 h ^-1 , the volume ratio of hydrogen / feed 100-1000 nm ³ / m ³ in the presence of a heterogeneous catalyst containing a bimetallic complex compound [M (H ₂ O) _x (L) _y ] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ], where: L is a partially deprotonated form of citric acid C ₆ H ₆ O ₇ ; x is 0 or 2; y = 0 or 1; M - Co ²⁺ and / or Ni ²⁺ in an amount of 30-45 wt.%, Which corresponds to the content in the catalyst calcined at 550 ° C, wt.%: MoO ₃ -14,0-23,0; CoO and / or NiO - 3.6-6.0; B ₂ O ₃ - 0.6-2.6, Al ₂ O ₃ - the rest, and having a pore volume of 0.3-0.7 cm ³ / g, a specific surface area of 200-350 m ² / g and an average pore diameter of 9 -13 nm.

In order to increase the catalytic activity of the catalysts in their preparation, a support with improved texture characteristics is used, while the specific surface area of the catalyst reaches 300 m ² / g and the average pore diameter is in the range of 7-13 nm, which provides good access of hydrotreated molecules to the active centers of the catalyst . The use of silicon as a modifying agent allows one to increase the catalytic activity in the reactions of hydrodesulfurization, hydrodeazotization, and hydrogenation due to a change in the texture and acid properties of the catalyst. An increase in the proportion of silicon-containing components in the composition of the alumina carrier can lead to a change in the mechanical properties of the sample, as well as the creation of an excessive amount of acid centers on the surface, which will lead to a decrease in catalytic stability due to accelerated coke deposition.

The most common way of introducing silicon into the catalyst is to incorporate silicon-containing components in the carrier at the molding stage. So, for example, many catalysts are known [RU 2534997, B01J37 / 02, 12/10/2014; RU 2534998, B01J23 / 882, 12/10/2014; RU 2007115098, B01J21 / 12, 10.11.2008; CN 200380105512, B01J21 / 12, 11.28.2002; WO 2006032782A1, B01J21 / 12, 03.30.2006], carriers for which are prepared by mixing dry powders of aluminosilicate and a binder component, followed by extrusion and heat treatment.

Catalysts are known in which silicon is introduced together with active metals [RU 2573561, B01J23 / 882, 01/20/2016; RU 2008120436, B01J23 / 08, 11.27.2009].

Carriers for hydrotreating catalysts are also known in which a silicon-containing modifier solution is added to the pseudoboehmite powder at the stage of preparing the molding material. So, for example, a known catalyst for producing low sulfur diesel fuel [CN 102284300, B01J27 / 19, 06.21.2010], containing in its composition W-Mo-Ni-P active component, wt.%: WO ₃ - 5-25, MoO ₃ - 8-20, NiO - 2-9, P - 1.0-5 and additives of 0.2-10% alkaline, alkaline earth or rare earth metals to a silicon-aluminum carrier. The mass ratio of SiO ₂ / Al ₂ O ₃ in the carrier is 6-13, glacial acetic acid / Al ₂ O ₃ is 0.02-0.06, citric acid / Al ₂ O ₃ is 0.01-0.04, ammonia / Al ₂ O ₃ - 0.30-0.80, pore former / Al ₂ O ₃ - 0.01-0.04. The preparation of the carrier includes mixing the pseudoboehmite powder and the blowing agent powder for 5-10 minutes until homogeneous, preparing the silica sol solution, adding the silica sol solution to the molding mass and mixing until the modifier is evenly distributed. Then add solutions of citric acid, acetic acid and ammonia, and stirring. Molding is performed through a die in the form of a trefoil with a diameter of 1.6 mm, followed by drying for 4 hours at 80-130 ° C and annealing for 3 hours at 550 ° C.

Closest to the proposed technical solution is described in the patent [RU 2691991, C10G 45/08, B01J 21/02, 06/19/19] a method for producing low-sulfur diesel fuel, which consists in hydrotreating straight-run or mixed raw materials with a high sulfur content at a temperature of 340-380 ° C, a pressure of 3.5-8.0 MPa, mass flow of raw materials 1.0-2.5 hours^-1, the volumetric ratio of hydrogen / feed 300-500 nm³/ m³ in the presence of a catalyst containing, wt.%: [Co (H₂O)₂(C₆H_fiveO₇)]₂[Mo₄O_eleven(C₆H_fiveO₇)₂] - 7.7-32.0; With₂[H₂P₂Mo_fiveO₂₃] - 11.1-29.0; the carrier is the rest; wherein the carrier contains, wt.%: aluminum borate Al₃Bo₆ with the structure of norbergite - 5.0-25.0; γ-Al₂O₃ - the rest, that in the case of sulfidation by known methods leads to the production of a catalyst that contains wt.%: Mo - 10.0-16.0; Co - 2.7-4.5; P - 0.8-1.8; S 6.7-10.8; the carrier is the rest; wherein the carrier contains, wt.%: aluminum borate Al₃Bo₆ with the structure of norbergite - 5.0-25.0; γ-Al₂O₃ - the rest. The catalyst has a specific surface area of 120-190 m²/ g, pore volume 0.35-0.65 cm³/ g, the average pore diameter of 7-12 nm, and is a particle with a cross section in the form of a circle, trefoil or tetrafoil with a diameter of the circumscribed circle of 1.0-1.6 mm and a length of up to 20 mm

A common drawback for all of the above hydrotreating processes and catalysts for these processes is that using them either it is not possible to achieve a residual sulfur content in diesel fuels of 10 ppm, or a predetermined residual sulfur content is achieved at high temperatures of the hydrotreating process, excluding their use in factory settings.

The invention solves the problem of creating an improved method for producing low-sulfur diesel fuel.

The problem is solved by the method of producing low-sulfur diesel fuel, which consists in hydrotreating straight-run or mixed raw materials with a high sulfur content at a temperature of 340-380 ° C, a pressure of 3.5-8.0 MPa, a mass flow rate of 1.0-2.5 hours ^-1 , the volumetric ratio of hydrogen / feed 300-500 nm ³ / m ³ in the presence of a catalyst containing, wt.%: [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] - 7.7-32.0; Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] - 11.1-29.0; the carrier is the rest; wherein the carrier contains, wt.%: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 2.0-20.0, aluminum borate Al ₃ BO ₆ with norbergite structure - 5.0-25 , 0, γ-Al ₂ O ₃ - the rest.

The catalyst has a specific surface area of 120-180 m ² / g, a pore volume of 0.30-0.50 cm ³ / g, an average pore diameter of 7-12 nm and is a particle with a cross section in the form of a circle, trefoil or four-leaf with a diameter of the circumference described 1.0-1.6 mm and up to 20 mm long. After sulfidation by known methods, the catalyst contains, by weight. %: Mo - 10.0-16.0; Co - 2.7-4.5; P - 0.8-1.8; S 6.7-10.8; the carrier is the rest; wherein the carrier contains, wt.%: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 2.0-20.0, aluminum borate Al ₃ BO ₆ with norbergite structure - 5.0-25 , 0, γ-Al ₂ O ₃ - the rest.

The silicon dioxide SiO ₂ included in the support is an amorphous phase and has particles of 3-20 nm in size. The carrier is obtained by adding a silica sol solution to pseudoboehmite powder at the stage of preparing the molding material. Silica sol has particles of 3-8 nm in size, a pH value of 8.5-9.5, a mass concentration of silicon dioxide of 14-16 wt.%, A specific surface area of 360-700 m ² / g.

The aluminum borate Al ₃ BO ₆ included in the support with the structure of norbergite is a particle with sizes from 10 to 200 nm, characterized by interplanar distances of 3.2 and 2.8 Å, with an angle between them of 53.8 °.

The main feature of the proposed method of producing low-sulfur diesel fuel compared with the prior art is that the hydrotreating process is carried out at a temperature of 340-380 ° C, a pressure of 3,5-8,0 MPa, a mass flow feed 1.0-2.5 h ^{- 1} , the volumetric ratio of hydrogen / feed 300-500 nm ³ / m ³ in the presence of a catalyst, which contains, wt.%: [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ ( C ₆ H ₅ O ₇ ) ₂ ] - 7.7-32.0; Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] - 11.1-29.0; the carrier is the rest; wherein the carrier contains, wt.%: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 2.0-20.0, aluminum borate Al ₃ BO ₆ with norbergite structure - 5.0-25 , 0, γ-Al ₂ O ₃ - the rest. The output of the content of the catalyst components beyond the claimed framework leads to the further production of a catalyst with reduced activity. The indicated chemical composition of the catalyst contributes to the further selective formation of the type II phase II, which is most active in the targeted hydrotreatment reactions of CoMoS, which ensures the production of low-sulfur diesel fuel at a low temperature of the hydrotreatment process.

The second distinguishing feature of the proposed method compared to the prototype is that the catalyst used has a specific surface area of 120-180 m ² / g, a pore volume of 0.30-0.50 cm ³ / g, an average pore diameter of 7-12 nm, and represents particles with a cross section in the form of a circle, trefoil or four-leaf with a diameter of the circumscribed circle of 1.0-1.6 mm and a length of up to 20 mm

The technical result consists of the following components:

1. The presence of two bimetallic complex compounds [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] and Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] prevents their crystallization at the drying stage and provides further formation in the catalyst, during its operation in hydrotreating highly dispersed particles of the most active component — CoMoS type II phase.

2. The inventive chemical composition of the catalyst determines the maximum activity in the target reactions occurring during hydrotreatment of hydrocarbons. The presence of phosphorus, silicon and boron compounds in the form of a cobalt salt in the form of cobalt salt diphosphate pentamolybdate Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ], an amorphous phase of silicon dioxide SiO ₂ with a particle size of 3-20 nm and aluminum borate Al ₂ BO ₆ with the structure of norbergite with the claimed concentration provides a level of acidity that contributes to the maximum conversion of nitrogen compounds that inhibit the conversion of sulfur-containing compounds.

The presence in the composition of the carrier of aluminum borate Al ₃ BO ₆ with the structure of norbergite and γ-Al ₂ O ₃ in the claimed concentration range is confirmed by the data of elemental analysis, X-ray phase analysis (XRD) and high resolution transmission electron microscopy (TEMP). According to XRD data, the radiographs of the carrier contain characteristic peaks of γ-Al2O3 37.2; 39.5; 45.7 and 67.1, due to their high intensity, overlapping peaks 37.5; 43.5; 63 and 68, characteristic of aluminum borate Al ₃ BO ₆ with a norbergite structure [Ceramic International, 32 (2006) 365], which are present on X-ray diffraction patterns in the form of low-intensity lines, slightly exceeding the noise level. The presence in the composition of the carrier of particles of silicon dioxide SiO _{2 is} confirmed by TEMP data (Figure 1 - TEMP image of the carrier with the presence of particles of SiO ₂ ). In the TEMP image, amorphous silicon dioxide SiO ₂ particles are observed, having sizes from 3 to 20 nm, uniformly distributed over the surface of the carrier. The presence of aluminum borate Al ₃ BO ₆ with the structure of norbergite in the carrier is confirmed by TEMP data (Fig. 2). On particles of Al ₂ O ₃ agglomerates of lamellar particles with sizes from 10 to 200 nm are observed. When measuring interplanar distances, these particles belong to the Al ₃ BO ₆ phase _. So, according to the FFT image (presented in the tab on Fig. 2 TEMP image of the microstructure of the Al ₃ BO ₆ particle), the TEMVR image shows distances of 3.2 and 2.8 A, the angle between of them is 53.8, which corresponds to the systems of planes (201) and (121) in the crystal lattice of Al ₃ BO ₆ .

Description of the proposed technical solution:

Hydrotreating straight-run or containing up to 30% secondary fractions of diesel fractions with a boiling end up to 360 ° C, is carried out at a temperature of 340-380 ° C, a pressure of 3.5-8.0 MPa, a mass flow of raw materials of 1.0-2.5 h ^{- 1} , the volume ratio of hydrogen / feed 300-500 nm ³ / m ³ in the presence of a catalyst containing, wt.%: [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] - 7.7-32.0; Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] - 11.1-29.0; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 2.0-20.0; Al ₃ BO ₆ - 5.0-25.0; γ-Al ₂ O ₃ - the rest, which in the case of sulfidation by known methods leads to the production of a catalyst that contains wt. %: Mo - 10.0-16.0; Co - 2.7-4.5; P - 0.8-1.8; S 6.7-10.8; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 2.0-20.0; Al ₃ BO ₆ - 5.0-25.0; γ-Al ₂ O ₃ - the rest. The used catalyst has a specific surface area of 120-180 m ² / g, a pore volume of 0.30-0.50 cm ³ / g, an average pore diameter of 7-12 nm, and is a particle with a cross-section in the form of a circle, trefoil or four-leaf with a diameter the circumference described is 1.0-1.6 mm and a length of up to 20 mm.

The invention is illustrated by the following examples:

Example 1. According to the existing decision [RU No. 2691991, C10G 45/08, B01J 21/02, 06/19/19]

A support is prepared containing aluminum borate Al ₂ BO ₆ with the structure of norbergite and γ-Al ₂ O ₃ . Take a sample of the product of thermal activation of hydrargillite (PTAG) with the following characteristics: mass fraction of the X-ray amorphous phase,%, not less than 80; the proportion of weight loss during calcination at (900 ± 20) ° C,% - 10-12; specific surface, m ² / g, not less than 120; total pore volume (moisture capacity), cm ³ / g, not less than 0.1; mass fraction of gibbsite (hydrargillite),%, not more than 5; mass fraction of sodium oxide,%, not more than 0.5. A portion is crushed in a planetary mill to particles with an average size of 20 microns.

A portion of the ground powder is hydrated with stirring for two hours in weakly concentrated nitric acid solutions heated to 50 ° C (acid module 0.03). Then the resulting suspension is filtered under vacuum and washed repeatedly with distilled water. The result is a wet cake. Hydrothermal treatment of the washed precipitate is carried out in an autoclave in aqueous solutions of nitric acid with the addition of a given amount of boric acid at a solution temperature above 100 ° C. After completion of the hydrothermal treatment, the solution is cooled to room temperature, the autoclave is unloaded, the contents of the vessel are repulped with distilled water to obtain a suspension suitable for spray drying. Next, drying is carried out on a spray dryer at an air inlet temperature of 280 ° C and continuous suspension stirring. The finished powder of boron-containing aluminum hydroxide is discharged from a glass of a cyclone dust collector of a spray dryer.

Next, prepare the molding mass by mixing and peptization of the obtained powder in a laboratory mixer with Z-shaped blades in the presence of an aqueous solution of ammonia. An ammonia solution was prepared so that the amount of 25% aqueous ammonia was 1.5 ml per 40 g of powder after spray drying. The finished plastic mass is loaded from the mixer into the molding cylinder of the laboratory extruder and pressed through the hole of the die, providing extrudates of the finished carrier with a cross-section in the shape of a circle, trefoil or four-leaf with a size from the top of the trefoil to the middle of the base from 1.0 to 1.6 mm. Then heat treatment of the extrudates is carried out, including drying and calcining. Extrudates are dried in an oven at a temperature of (110 ± 10) ° C for 2 hours. Heat treatment is carried out in a muffle furnace with compressed air supplied to the furnace. The extrudates in a porcelain cup were placed in an oven and calcined at a temperature of (550 ± 10) ° С for 4 hours.

The finished carrier contains, by weight. %: aluminum borate Al ₃ BO ₆ with norbergite structure - 5.0-25.0; γ-Al ₂ O ₃ - the rest, and has a specific surface area of 200-280 m ² / g, a pore volume of 0.6-0.8 cm ³ / g, an average pore diameter of 7-12 nm, and is a particle with a cross section of in the form of a circle, shamrock or four-leafed leaf with a diameter of the circumscribed circle of 1.0-1.6 mm and a length of up to 20 mm. The aluminum borate Al ₃ BO _{6, which} is part of the support, with the structure of norbergite, is a particle with sizes from 10 to 200 nm, characterized by interplanar distances of 3.2 and 2.8 A, with an angle between them of 53.8.

Using this support, a supported catalyst is prepared. A solution is prepared containing the cobalt salt of molybdenum citrate [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] and the cobalt salt of pentamolybdate diphosphate Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ]. To do this, 2.92 ml of a 85% phosphoric acid solution, 11.3 g of citric acid C ₆ H ₈ O _{7 are} successively dissolved in 30 ml of distilled water with stirring; 29.35 g of ammonium paramolybdate (NH ₄ ) ₆ Mo ₇ O ₂₄ x 4H ₂ O and 8.54 g of cobalt (II) carbonic basic aqueous CoCO ₃ ⋅mCo (ОН) ₂ ⋅nH ₂ O. After complete dissolution of all components, adding distilled water the volume of the solution was adjusted to 67 ml.

100 g of the carrier are impregnated with a moisture capacity of 67 ml of a solution of bimetallic complex compounds [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] and Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] at 50 ° C for 25 minutes. Then the catalyst is dried in air at 120 ° C for 4 hours

The catalyst is sulfidized in a straight-run diesel fraction containing an additional 1.5 wt.% Sulfiding agent - dimethyldisulfide (DMDS), with a volumetric feed rate of sulfiding mixture of 2 h ^-1 and a hydrogen / feed ratio = 300 according to the following program:

- 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 temperature rise rate 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

The result is a catalyst that contains, wt.%: Mo - 12.5; Co - 3.85; S is 8.3; the carrier is the rest; wherein the carrier contains, wt.%: aluminum borate Al ₃ BO ₆ with the structure of norbergite - 12.0; sodium - 0.03; γ-Al ₂ O ₃ - the rest.

The catalyst is tested in the hydrotreating of mixed diesel fuel prepared by mixing, vol. % - 87 - straight run diesel fraction; 11 - light gas oil catalytic cracking, 2 - light gas oil delayed coking containing 0.374% sulfur, 200 ppm nitrogen, having a density of 0.866 g / cm ³ , boiling range 186-360 ° C, T ₉₅ - 350 ° C. Hydrotreating conditions: the volumetric feed rate of 2.5 h ^-1 , the ratio of N ₂ / feed = 500 nm ³ N ₂ / m ^{3 of} feed, a pressure of 3.8 MPa, a starting temperature of 350 ° C. Further, the temperature rose in jumps of 10 ° C per day to 370 ° C. If the residual sulfur content in the resulting diesel fuel is not reached 10 ppm at 370 ° C, the temperature rises by 1 ° C to a value at which the residual sulfur content in the hydrotreated product becomes 10 ppm.

Examples 2-7 illustrate the proposed technical solution.

Example 2

A powder of boron-containing aluminum hydroxide is prepared according to the procedure described in example 1.

A sample of 150 g of powder is placed in a trough of a mixer with Z-shaped blades and 15.3 g of a silica sol solution containing a mass fraction of silica of 15.0 wt. % The mass is stirred for 10 minutes to evenly distribute the particles of silica and pseudoboehmite powder, after which a 2.5% ammonia solution is added and mixed for 20 minutes. After that, the plastic molding mass is extruded at a pressure of 60.0 MPa through a die, which provides particles with a cross section in the form of a trefoil with a diameter of the circumference of 1.3 mm The formed granules are dried at a temperature of 120 ° C and calcined at a temperature of 550 ° C.

The result is a carrier containing, in wt.%: Silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 2.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 11.8; γ-Al ₂ O ₃ - the rest. The carrier has a specific surface area of 250 m ² / g, a pore volume of 0.58 cm ³ / g, an average pore diameter of 9.8 nm and represents particles with a cross section in the form of a trefoil with a diameter of the circumscribed circle of 1.3 mm and a length of up to 20 mm.

The catalyst is prepared by impregnation by moisture capacity or from excess solution, similarly to the method described in example 1.

The catalyst contains, wt.%: [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] - 15.4; Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] - 15.3; the carrier is the rest; wherein the carrier contains, wt.%: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 2.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 11.8; γ-Al ₂ O ₃ - the rest.

The catalyst has a specific surface area of 150 m ² / g, a pore volume of 0.40 cm ³ / g, an average pore diameter of 10 nm and represents particles with a cross section in the form of a trefoil with a diameter of the circumscribed circle of 1.3 mm and a length of up to 20 mm. The silicon dioxide SiO ₂ included in the catalyst is an amorphous phase and has particles of 3-20 nm in size. The aluminum borate catalyst Al ₃ BO ₆ with the structure of norbergite, which is a part of the catalyst, is a particle with sizes from 10 to 200 nm, characterized by interplanar distances of 3.2 and 2.8 A, with an angle between them of 53.8.

Next, the catalyst is sulfidized analogously to example 1. The result is a catalyst that contains, by weight. %: Mo - 12.0; Co - 3.2; P is 1.0; S is 8.1; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 2.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 11.8; γ-Al ₂ O ₃ - the rest.

Next, hydrotreating the hydrocarbon feed is carried out analogously to example 1.

Example 3

A powder of boron-containing aluminum hydroxide is prepared according to the procedure described in example 1.

The carrier is prepared according to the procedure described in example 2, with the exception that 70.33 g of silica sol solution containing a mass fraction of silica of 15.0 wt.% Is added to pseudoboehmite powder. %

The result is a carrier containing, in wt.%: Silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 8.6; aluminum borate Al ₃ BO ₆ with a norbergite structure - 11.0; γ-Al ₂ O ₃ - the rest. The carrier has a specific surface area of 256 m ² / g, a pore volume of 0.61 cm ³ / g, an average pore diameter of 9.9 nm and represents particles with a cross section in the form of a trefoil with a circumscribed circle diameter of 1.3 mm and a length of up to 20 mm.

A solution containing the cobalt salt of molybdenum citrate [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] and the cobalt salt of pentamolybdate diphosphate Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ], used to prepare the catalyst according to the method described in example 1.

The catalyst contains, wt.%: [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] - 15.4; Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] - 15.3; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 8.6; aluminum borate Al ₃ BO ₆ with a norbergite structure - 11.0; γ-Al ₂ O ₃ - the rest.

The catalyst has a specific surface area of 154 m ² / g, a pore volume of 0.41 cm ³ / g, an average pore diameter of 10.7 nm and represents particles with a cross section in the form of a trefoil with a diameter of the circumscribed circle of 1.3 mm and a length of up to 20 mm. The silicon dioxide SiO ₂ included in the catalyst is an amorphous phase and has particles of 3-20 nm in size. The aluminum borate catalyst Al ₃ BO ₆ with the structure of norbergite, which is a part of the catalyst, is a particle with sizes from 10 to 200 nm, characterized by interplanar distances of 3.2 and 2.8 A, with an angle between them of 53.8.

Next, the catalyst is sulfidized analogously to example 1. The result is a catalyst that contains, by weight. %: Mo - 12.0; Co - 3.2; P is 1.0; S is 8.1; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 8.6; aluminum borate Al ₃ BO ₆ with a norbergite structure - 11.0; γ-Al ₂ O ₃ - the rest.

Next, hydrotreating the hydrocarbon feed is carried out analogously to example 1.

Example 4

A powder of boron-containing aluminum hydroxide is prepared according to the procedure described in example 1.

The carrier is prepared according to the procedure described in example 2, except that 132 g of silica sol solution containing a mass fraction of silica of 15.0 wt.% Is added to pseudoboehmite powder. %

The result is a carrier containing, in wt.%: Silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 15.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 10.2; γ-Al ₂ O ₃ - the rest. The carrier has a specific surface area of 264 m ² / g, a pore volume of 0.62 cm ³ / g, an average pore diameter of 9.6 nm and is a particle with a cross section in the form of a trefoil with a diameter of the circumscribed circle of 1.3 mm and a length of up to 20 mm.

A solution containing the cobalt salt of molybdenum citrate [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] and the cobalt salt of pentamolybdate diphosphate Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ], used to prepare the catalyst according to the method described in example 1.

The catalyst contains, wt.%: [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] - 15.4; Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] - 15.3; the carrier is the rest; wherein the carrier contains, wt.%: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 15.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 10.2; γ-Al ₂ O ₃ - the rest. The catalyst has a specific surface area of 158 m ² / g, a pore volume of 0.41 cm ³ / g, an average pore diameter of 10.7 nm and represents particles with a cross section in the form of a trefoil with a diameter of the circumscribed circle of 1.3 mm and a length of up to 20 mm. The silicon dioxide SiO ₂ included in the catalyst is an amorphous phase and has particles of 3-20 nm in size. The aluminum borate catalyst Al ₃ BO ₆ with the structure of norbergite, which is a part of the catalyst, is a particle with sizes from 10 to 200 nm, characterized by interplanar distances of 3.2 and 2.8 A, with an angle between them of 53.8.

Next, the catalyst is sulfidized analogously to example 1. The result is a catalyst that contains, by weight. %: Mo - 12.0; Co - 3.2; P is 1.0; S is 8.1; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 15.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 10.2; γ-Al ₂ O ₃ - the rest.

Next, hydrotreating the hydrocarbon feed is carried out analogously to example 1.

Example 5

A powder of boron-containing aluminum hydroxide is prepared according to the procedure described in example 1.

The carrier is prepared according to the procedure described in example 2, except that 186.7 g of silica sol containing 15% by weight mass fraction of silica are added to pseudoboehmite powder.

The result is a carrier containing, in wt.%: Silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 20.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 9.6; γ-Al ₂ O ₃ - the rest. The carrier has a specific surface area of 267 m ² / g, a pore volume of 0.61 cm ³ / g, an average pore diameter of 9.4 nm and represents particles with a cross section in the form of a trefoil with a diameter of the circumscribed circle of 1.3 mm and a length of up to 20 mm.

A solution containing the cobalt salt of molybdenum citrate [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] and the cobalt salt of pentamolybdate diphosphate Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ], used to prepare the catalyst according to the method described in example 1.

The catalyst contains, wt.%: [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] - 15.4; Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] - 15.3; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 20.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 9.6; γ-Al ₂ O ₃ - the rest. The catalyst has a specific surface area of 164 m ² / g, a pore volume of 0.41 cm ³ / g, an average pore diameter of 10.3 nm and represents particles with a cross section in the form of a trefoil with a diameter of the circumscribed circle of 1.3 mm and a length of up to 20 mm. The silicon dioxide SiO ₂ included in the catalyst is an amorphous phase and has particles of 3-20 nm in size. The aluminum borate catalyst Al ₃ BO ₆ with the structure of norbergite, which is a part of the catalyst, is a particle with sizes from 10 to 200 nm, characterized by interplanar distances of 3.2 and 2.8 A, with an angle between them of 53.8.

Next, the catalyst is sulfidized analogously to example 1. The result is a catalyst that contains, by weight. %: Mo - 12.0; Co - 3.2; P is 1.0; S is 8.1; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 20.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 9.6; γ-Al ₂ O ₃ - the rest.

Next, hydrotreating the hydrocarbon feed is carried out analogously to example 1.

Example 6

A powder of boron-containing aluminum hydroxide is prepared according to the procedure described in example 1.

The carrier is prepared according to the procedure described in example 4, with the exception that the molding material is extruded at a pressure of 60.0 MPa through a die, providing particles with a cross section in the form of a four-leaf with a diameter of the circumference of 1.6 mm.

The result is a carrier containing, in wt.%: Silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 15.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 10.2; γ-Al ₂ O ₃ - the rest. The carrier has a specific surface area of 266 m ² / g, a pore volume of 0.62 cm ³ / g, an average pore diameter of 9.6 nm and is a particle with a four-leaf cross-section with a diameter of the circumscribed circle of 1.6 mm and a length of up to 20 mm.

A solution containing the cobalt salt of molybdenum citrate [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] and the cobalt salt of pentamolybdate diphosphate Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ], used to prepare the catalyst according to the method described in example 1.

The catalyst contains, wt.%: [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] - 15.4; Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] - 15.3; the carrier is the rest; wherein the carrier contains, wt.%: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 15.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 10.2; γ-Al ₂ O ₃ - the rest. The catalyst has a specific surface area of 159 m ² / g, a pore volume of 0.41 cm ³ / g, an average pore diameter of 10.7 nm and represents particles with a four-leaf cross-section with a diameter of the circumscribed circle of 1.6 mm and a length of up to 20 mm. The silicon dioxide SiO ₂ included in the catalyst is an amorphous phase and has particles of 3-20 nm in size. The aluminum borate catalyst Al ₃ BO ₆ with the structure of norbergite, which is a part of the catalyst, is a particle with sizes from 10 to 200 nm, characterized by interplanar distances of 3.2 and 2.8 A, with an angle between them of 53.8.

Next, the catalyst is sulfidized analogously to example 1. The result is a catalyst that contains, by weight. %: Mo - 12.0; Co - 3.2; P is 1.0; S is 8.1; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 15.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 10.2; γ-Al ₂ O ₃ - the rest.

Next, hydrotreating the hydrocarbon feed is carried out analogously to example 1.

Example 7

A powder of boron-containing aluminum hydroxide is prepared according to the procedure described in example 1.

The carrier is prepared according to the procedure described in example 4, with the exception that the molding mass is extruded at a pressure of 60.0 MPa through a die, providing particles with a cross-section in the form of a circle with a diameter of the circumference of 1.6 mm described.

The result is a carrier containing, in wt.%: Silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 15.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 10.2; γ-Al ₂ O ₃ - the rest. The carrier has a specific surface area of 265 m ² / g, a pore volume of 0.62 cm ³ / g, an average pore diameter of 9.6 nm and is a particle with a cross-section in the form of a circle with a diameter of the circumscribed circle of 1.6 mm and a length of up to 20 mm.

A solution containing the cobalt salt of molybdenum citrate [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] and the cobalt salt of pentamolybdate diphosphate Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ], used to prepare the catalyst according to the method described in example 1.

The catalyst contains, by weight. %: [Co (H ₂ O) ₂ (C ₆ H ₅ O ₇ )] ₂ [Mo ₄ O ₁₁ (C ₆ H ₅ O ₇ ) ₂ ] - 15.4; Co ₂ [H ₂ P ₂ Mo ₅ O ₂₃ ] - 15.3; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 15.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 10.2; γ-Al ₂ O ₃ - the rest. The catalyst has a specific surface area of 158 m ² / g, a pore volume of 0.41 cm ³ / g, an average pore diameter of 10.7 nm and represents particles with a cross section in the form of a circle with a diameter of the circumscribed circle of 1.6 mm and a length of up to 20 mm. The silicon dioxide SiO ₂ included in the catalyst is an amorphous phase and has particles of 3-20 nm in size. The aluminum borate catalyst Al ₃ BO ₆ with the structure of norbergite, which is a part of the catalyst, is a particle with sizes from 10 to 200 nm, characterized by interplanar distances of 3.2 and 2.8 A, with an angle between them of 53.8.

Next, the catalyst is sulfidized analogously to example 1. The result is a catalyst that contains, by weight. %: Mo - 12.0; Co - 3.2; P is 1.0; S is 8.1; the carrier is the rest; wherein the carrier contains, by weight. %: silicon dioxide SiO ₂ , which is an amorphous phase and having a particle size of 3-20 nm - 15.0; aluminum borate Al ₃ BO ₆ with a norbergite structure — 10.2; γ-Al ₂ O ₃ - the rest.

Next, hydrotreating the hydrocarbon feed is carried out analogously to example 1.

The results of testing the catalysts in hydrotreatment are shown in the table.

Thus, as can be seen from the above examples, the proposed method for producing low-sulfur diesel fuel due to the optimal chemical composition of the catalyst used, allows to obtain diesel fuels with a much lower sulfur and nitrogen content and at lower hydrotreating temperatures than in the prototype method.

Table - Residual sulfur and nitrogen in hydrotreatment products

Example Number 1 (prototype) 2 3 4 five 6 7 Residual sulfur content at 370 ° С, ppm 18,4 17.0 10.6 9.0 13,4 9,4 9.5 The residual nitrogen content at 370 ° C, ppm 8.2 8.3 6.1 5,0 7.2 5.2 5.3

Claims (2)

1. The method of producing low sulfur diesel fuel, which consists in hydrotreating straight-run and mixed diesel fractions with a high sulfur content in a stream of hydrogen-containing gas at a temperature of 340-380 ° C, a pressure of 3.5-8.0 MPa, a mass flow of raw materials of 1.0-2 5 h^-1 , the volume ratio of hydrogen / feed 300-500 m³/ m³ in the presence of a heterogeneous catalyst composition: wt.%, [Co (H₂O)₂(C₆H_fiveO₇)]₂[Mo₄O_eleven(C₆H_fiveO₇)₂] - 7.7-32.0; With₂[N₂R₂Mo_fiveABOUT₂₃] - 11.1-29.0; the carrier is the rest; wherein the carrier contains, wt.%: silicon dioxide SiO₂representing an amorphous phase and having a particle size of 3-20 nm, 2.0-20.0, aluminum borate Al₃Bo₆ with the structure of norbergite - 5.0-25.0, γ-Al₂O₃ - the rest; the catalyst has a specific surface area of 120-180 m²/ g, pore volume 0.30-0.50 cm³/ g, the average pore diameter of 7-12 nm and is a particle with a cross section in the form of a circle, trefoil or tetrafoil with a diameter of the circumscribed circle of 1.0-1.6 mm and a length of up to 20 mm; the catalyst before hydrotreating is sulfidized to obtain a catalyst that contains, wt.%: Mo - 10.0-16.0; Co - 2.7-4.5; P - 0.8-1.8; S 6.7-10.8; the carrier is the rest; wherein the carrier contains, wt.%: silicon dioxide SiO₂representing an amorphous phase and having a particle size of 3-20 nm - 2.0-20.0, aluminum borate Al₃Bo₆ with norbergite structure - 5.0-25.0, γ-Al₂O₃ - the rest. 2. The method according to p. 1, characterized in that straight-run or containing up to 30% of secondary fractions diesel fractions with a boiling end up to 360 ° C are used as feedstock.

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