RU2631424C2 - Deep hydrofining catalyst of oil fractions and method of its preparation - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method includes the impregnation of the alumina carrier with the metal compounds solution of groups VIII, VI and V. In this case, the joint impregnation solution MoO₃ and/or WO₃, not necessarily V₂O₅, from 0.33 to 0.42 ml of 85% H₃PO₄, cobalt nitrate or nickel in 30% solution of H₂O₂ at pH of the impregnation solution 2.0-3.5 and provide the single alumina impregnation with the final calcination of the finished catalyst. The catalyst for deep hydrofining of oil fractions is also proposed.

EFFECT: invention allows to simplify the preparation process of highly active catalyst for deep hydrofining of oil fractions.

9 cl, 2 tbl, 6 ex

Description

The invention relates to the field of chemistry, and in particular to the field of production of catalysts intended for deep hydrotreating of oil fractions, and can be used in the oil refining and petrochemical industries.

Known catalysts for hydrotreating diesel fractions from sulfur compounds contain molybdenum and / or tungsten and cobalt and / or nickel in oxide form deposited on the surface of a porous heat-resistant metal oxide. A known method for the preparation of hydrodesulfurization catalysts containing Co (Ni) -Mo (W) oxides dispersed on Al ₂ O ₃ is the extrusion of a mass of aluminum hydroxide mixed with Co and / or Ni and Mo and / or W salts. In this case, all active the components or a part thereof are added to aluminum hydroxide peptized with any monobasic acid [RU 2189860, B01J 37/04, 23/882, 09/27/02; 2137541, B01J 23/88, C10G 45/08, 09/20/99]. Soluble molybdenum compounds, mainly ammonium molybdenum acid (NH ₄ ) ₆ Mo ₇ O ₂₄ ⋅ 4H ₂ O, and cobalt and nickel salts, mainly nitrates, are used as precursors of the active component [RU 2137541, B01J 23/88, 09/20/99] . Phosphoric tungsten acid is also used for the introduction of tungsten [RU 2566307, B01J 23/88, 10.20.2015]. The main disadvantage of the catalysts obtained by this method is their low activity, which does not allow to obtain highly purified diesel fuel (with a sulfur content of less than 350 ppm). This is due to the fact that part of the active components introduced into the mass of aluminum hydroxide is not located on the active surface of the catalyst, but is enclosed in a volume of Al ₂ O ₃ .

Another known method for the preparation of hydrodesulfurization catalysts of the type CoO (NiO) -MoO ₃ (WO ₃ ) / Al ₂ O ₃ is a method for impregnating alumina with solutions of active component compounds, drying and calcining. The application of the active components is carried out both by sequential impregnation from separate solutions, and by single-stage impregnation from a joint solution. To create stable joint impregnating solutions, a concentrated solution of ammonia is also used [a.s. USSR 1297899 B01J 23/88. No. 1,680304; declared 11/22/1989; publ. 01/01/1991. Bull. No. 36], which forms complex compounds with Co (Ni), which does not allow the formation of precipitation of molybdates of these metals. In the case of ammonia impregnation in an insufficiently concentrated ammonia solution, precipitation of Co or Ni molybdates is possible.

To stabilize the joint solutions of the compounds Co (Ni) and Mo (W), complexing organic acids can be used [A. with. USSR 1297899 B01J 23/88. No. 3954947 / 31-04; declared 08/01/85; publ. 03/23/87, Bull. No. 11 - 3 pp.]. The disadvantage of this method of preparation of the catalyst is the high temperature of the calcination of the catalyst (550 ° C) after applying the active components by impregnation from a joint solution of molybdenum and nickel or cobalt salts. It is known that at temperatures above 500 ° C the formation of spinels is possible - compounds of aluminum oxide and nickel oxide or cobalt. If the catalyst after calcining Ni or Co salts on a support containing alumina is calcined at temperatures above 500 ° C, part of the promoter (Ni or Co) binds to the support and is not part of the active CoMoS phase, which is formed after sulfidation, t .e. actually becomes inactive in hydrotreating reactions.

Closest to the proposed solution are a catalyst and a method for its preparation, comprising impregnating an alumina carrier with a joint solution of molybdenum heteropoly compounds - 10-molybdodicobaltate (III) ammonium (NH ₄ ) ₆ [Co ₂ Mo ₁₀ O ₃₈ H ₄ ] ⋅ 7H ₂ O or 6- ammonium molybdocobaltate (II) ammonium (NH ₄ ) ₄ [Co (OH) ₆ Mo ₆ O ₁₈ ] ⋅6H ₂ O and cobalt nitrate or acetate at a Mo / Co molar ratio of 1.70-2.30, stabilized 25.8 -35.0 ml of 30% H ₂ O ₂ per 100 ml of impregnating solution, at a pH of 1.5-5.0, with the final calcination of the finished catalyst at temperatures not exceeding 400 ° C in approx excitatory or inert environment [RU 2385764, B01J 23/88, decl. 07/07/2008, publ. 04/10/2010. Bull. No. 10].

This solution makes it possible to obtain sufficiently active hydrotreating catalysts, allowing to reduce the residual sulfur content in hydrogenates to less than 50 ppm. However, the preparation of these catalysts involves the use of inorganic compounds that are not produced by industry and the synthesis of which even in laboratory conditions is a complex and time-consuming process [Guide to inorganic synthesis. M .: Mir, 1986.- T. 6, p. 4904, 6-molybdocobaltate, s. 4906, 10-molybdodicobaltate]. This will lead to a significant increase in the cost of the catalyst, in the event that it will be possible to organize the synthesis of these compounds in the conditions of catalyst production.

The technical result of the present invention is to simplify the method of preparing a highly active catalyst by eliminating from the technology the synthesis step of 6-molybdocobaltate or 10-molybdicobaltate using a simple and cheap commercially available molybdenum compound - MoO ₃ . At the same time, at the stage of preparation of the impregnating solution, the formation of a peroxocomplex compound of molybdenum occurs.

The technical result of the present invention is also a method of creating a catalyst for the deep hydrotreating of oil fractions, wherein MoO ₃ , WO ₃ , V ₂ O ₅ are used to prepare the impregnating solution, which easily dissolve in a 30% aqueous solution of H ₂ O ₂ with the formation of Mo peroxo complexes, W and V [I.I. Volnov. Peroxocomplexes of chromium, molybdenum, tungsten. M .: Nauka, 1989]. Then the resulting solution is mixed with H ₃ PO ₄ , with an aqueous solution of cobalt nitrate or nickel. In the presence of H ₃ PO _4, peroxoheteropoly acids are formed in the solution, containing Mo and / or W, or Mo and V, or W and V. In the stage of impregnation of aluminum oxide, it is possible to modify its surface with phosphoric acid anions [Ferdous D., Dalai A. K., AdjayeJ., Et. al. Surface morphology of NiMo / Al ₂ O ₃ catalysts incorporated with boron and phosphorus: Experimental and simulation // Appl. Catal. - 2005. - V. 294. - P. 80-91.] Chemisorbed on the main OH groups. The conditions of carrier impregnation, drying and calcination of the finished catalyst provide the modification of alumina with phosphorus oxide. At the hydrothermal stage of catalyst synthesis, chemisorbed PMo _{12 is formed} [Okamoto Y., Gomi T., Mori Y., Imanaka T., Teranishi S. 12-Molybdophosphoric acid as starting material for Ni-Mo / Al ₂ O ₃ hydrodesulfurization catalysts // React . Kinet. Catal. Lett., V. 22, N 3-4, 417-420 (1983)], or PW ₁₂ , or mixed ligand PMo _n W _12-n , PMo _n V _12-n , PW _n V _12-n heteropoly complexes having external sphere as counterions Co ²⁺ or Ni ²⁺ . This ensures the promotion of molybdenum and tungsten Co or Ni, and eliminating the transition of Co or Ni to spinel.

A distinctive feature of the invention is the totality of the proposed solutions, including: use as starting compounds of active components for the synthesis of oxide catalysts; molybdenum oxide MoO ₃ , tungsten WO ₃ , optionally vanadium V ₂ O ₅ , dissolving them in a 30% solution of H ₂ O ₂ with the addition of 0.33 to 0.42 ml of an 85% solution of H ₃ PO ₄ ; Co or Ni nitrates; the molar ratio of Mo (W) / Co (Ni) = 1.60-2.40 in the impregnation solution and in the catalyst necessary to create a promoted sulfide phase; the pH of the impregnating solution is 2.0-3.5, at which the existence of heteropoly complexes is possible; calcination at 550 ° C for 1-2 hours of a weighed portion of the support, allowing removal of adsorbed H ₂ O from the support surface; subsequent evacuation of the weighed portion of the carrier before contacting it with the impregnating solution, which allows uniform impregnation of the entire active surface, including the surface of the "dead end"pores; the use of impregnation at elevated temperatures in the impregnating solution, which allows to maintain the chemical and physical stability of the solution; final calcination of the catalyst at temperatures of 350-400 ° C.

The technical result is also achieved by the fact that in a method for preparing a catalyst for deep hydrotreating oil fractions, comprising impregnating an alumina support with a solution of compounds of metals of groups VIII, VI and V groups, a joint impregnating solution of MoO ₃ and / or WO ₃ is prepared, not necessarily V ₂ O ₅ , from 0.33 to 0.42 ml of 85% H ₃ PO ₄ , cobalt or nickel nitrate in a 30% solution of H ₂ O ₂ at a pH of the impregnation solution of 2.0-3.5 and a single impregnation of aluminum oxide is carried out with the final calcination of the finished catalyst, the molar ratio Mo (W) / Co (Ni) = 1.60-2, 40, and the molar ratio of MoO ₃ : WO ₃ from 11: 1 to 1:11, the molar ratio of V / (Mo + W) = 1/11 or 2/10, while the pH of the impregnating solution is 2.0-3.5, the sample is weighed at 550 ° C for 1-2 hours and impregnated with a pre-evacuated carrier at temperatures from 50 to 95 ° C, and the final calcination of the catalyst is carried out at temperatures of 350-400 ° C.

The catalyst for the deep hydrotreating of oil fractions contains MoO ₃ , WO ₃ , CoO or NiO, deposited on alumina by impregnation, the catalyst contains from 1.4 to 19.0 wt.% MoO ₃ , from 2.2 to 30.6 wt.% WO ₃ , optionally up to 3.2 wt.% V ₂ O ₅ , from 4.1 to 6.2 wt.% CoO or NiO, from 0.7 to 1.6 wt.% P ₂ O ₅ , the rest is Al ₂ O ₃ at a molar ratio of MoO ₃ : WO ₃ from 11: 1 to 1:11, a molar ratio: V: (Mo + W) 1:11 or 2:10.

Such a chemical composition and a molar ratio of components ensures the formation of a series of Mo and W 12 heteropoly compounds at the hydrothermal stage of the synthesis of the catalyst. In this case, the central complexing atom may be P or V. Mo and / or W, V and Mo, V and W may be present in the ligand sphere. After sulfiding of the oxide precursor, the Co (Ni) -Mo (W, V) S / Al catalyst ₂ O ₃ has a regular layered structure, a high degree of promotion of the Mo (W, V) S ₂ phase with Co or Ni ions and an optimal dispersion of the active phase, which allows for deep hydrotreating of oil fractions.

The starting compounds for the preparation of a joint impregnating solution, the conditions for impregnating the support with a joint impregnating solution and calcining the prepared catalysts are given in table. 1. The carrier was an extrudate γ-Al ₂ O ₃ in the form of a trefoil with a diameter of 1.2-1.3 mm and a length of 4-6 mm. The catalysts were tested in the form of particles with a size of 0.25-0.5 mm, prepared by grinding and dispersing the initial granules of the calcined catalyst. The catalysts were sulfidized at atmospheric pressure and a temperature of 400 ° C in a mixture of 20% vol. H ₂ S and H ₂ for 2 hours. Testing of the activity of the catalysts was carried out in a laboratory flow unit under hydrogen pressure. Download sulfidized catalyst 20 cm ³ . The reactor is specially designed so that the test results of the catalysts coincide with the industrial data, which is confirmed by comparing the results of the experimental run in industry and testing on the same industrial catalyst using one raw material. The raw material for these test tests was a straight-run diesel fraction of 170-362 ° C with a density of 844 kg / m ³ , sulfur content 1,044 wt.% (1044 ppm), nitrogen content 0,013 wt.%, Aromatic hydrocarbon content 20,5 wt. % Test conditions: partial pressure of hydrogen 3.5 MPa, the multiplicity of hydrogen circulation 350 nl / l of raw materials, the volumetric feed rate of 2 h ^-1 , the temperature in the reactor 340 and 360 ° C. Hydrogenates were separated from hydrogen in a separator at a pressure almost equal to the pressure in the reactor and a temperature of 20 ° C, then subjected to treatment with 10% NaOH solution for 15 min, washed with distilled water to neutral wash water, dried over annealed overnight CaCl ₂ . Sulfur content was determined using an X-ray fluorescence analyzer. The average value was taken from three parallel measurements. The characteristics and test results of the catalysts are presented in table. 2.

EXAMPLES

Example 1

To prepare a joint impregnating solution of the compounds of the active components, 19.0 g of MoO _{3 are} dissolved by heating to 82 ° C 52.7 ml of a 30% solution of H ₂ O ₂ . To the resulting solution was added 0.37 ml of 85% H ₃ PO ₄ , 16.0 g of cobalt nitrate Co (NO ₃ ) ₂ ⋅ 6H ₂ O and stirred. The pH of the resulting solution is 2.5. An alumina carrier weighing 75.3 g is calcined at a temperature of 550 ° C, cooled in a desiccator above a desiccant (calcined anhydrous CaCl ₂ ), kept in vacuum for 30 minutes, then filled with a joint impregnating solution having a temperature of 50 ° C. The carrier is kept in an impregnating solution for 30 minutes. The resulting catalyst is dried at temperatures of 80, 100, 120 ° C for 2 hours at each temperature; then the temperature is increased at a rate of 1 ° C / min to a temperature of 400 ° C, at which the catalyst is calcined for 2 hours in a stream of air. The composition of the finished catalyst, wt. %: 19.0 MoO ₃ ; 4.1 CoO; 1.6 P ₂ O ₅ ; 75.3 Al ₂ O ₃ .

Example 2

To prepare a joint impregnating solution of the compounds of the active components, 19.0 g of MoO ₃ , 2.2 g of V ₂ O _{5 are} dissolved when heated to 82 ° C, 50.0 ml of a 30% solution of H ₂ O ₂ . To the resulting solution was added 0.40 ml of 85% H ₃ PO ₄ , 24.0 g of nickel nitrate Ni (NO ₃ ) ₂ · 6H ₂ O and stirred. The pH of the resulting solution is 3.5. The aluminum oxide support weighing 71.5 g is calcined at a temperature of 550 ° C, cooled in a desiccator above a desiccant (calcined anhydrous CaCl ₂ ), kept in vacuum for 30 minutes, then filled with a joint impregnating solution having a temperature of 90 ° C. The carrier is kept in an impregnating solution for 30 minutes. The resulting catalyst is dried at temperatures of 80, 100, 120 ° C for 2 hours at each temperature; then the temperature is increased at a rate of 1 ° C / min to a temperature of 400 ° C, at which the catalyst is calcined for 2 hours in a stream of air. The composition of the finished catalyst, wt. %: 19.0 MoO ₃ ; 4.1 NiO; 2.2 V ₂ O ₅ ; 1.2 P ₂ O ₅ ; 71.5 Al ₂ O ₃ .

Example 3

To prepare a joint impregnating solution of the compounds of the active components, 30.6 g of WO _{3 are} dissolved by heating to 82 ° C 45.2 ml of a 30% solution of H ₂ O ₂ . 0.37 ml of 85% H ₃ PO ₄ , 16.0 g of nickel nitrate Ni (NO ₃ ) ₂ ⋅ 6H ₂ O are added to the resulting solution and stirred. The pH of the resulting solution is 2.0. An alumina support weighing 64.6 g is calcined at a temperature of 550 ° C, cooled in a desiccator above a desiccant (calcined anhydrous CaCl ₂ ), kept in a vacuum for 30 min, then filled with a joint impregnating solution having a temperature of 70 ° C. The carrier is kept in an impregnating solution for 30 minutes. The resulting catalyst is dried at temperatures of 80, 100, 120 ° C for 2 hours at each temperature; then the temperature is increased at a rate of 1 ° C / min to a temperature of 400 ° C, at which the catalyst is calcined for 2 hours in a stream of air. The composition of the finished catalyst, wt. %: 30.6 WO ₃ ; 4.1 NiO; 0.7 P ₂ O ₅ ; 64.6 Al ₂ O ₃ .

Example 4

For the preparation of a joint impregnating solution of compounds of the active components 15.0 g of MoO ₃ ; 2.2 g of WO ₃ ; 3.2 g of V ₂ O _{5 are} dissolved by heating to 82 ° C. 52.0 ml of a 30% solution of H ₂ O ₂ . 0.38 ml of 85% H ₃ PO ₄ , 17.4 g of nickel nitrate Ni (NO ₃ ) ₂ ⋅ 6H ₂ O are added to the resulting solution and stirred. The pH of the resulting solution is 2.5. The alumina support weighing 74.2 g is calcined at a temperature of 550 ° C, cooled in a desiccator above a desiccant (calcined anhydrous CaCl ₂ ), kept in vacuum for 30 minutes, then filled with a joint impregnating solution having a temperature of 50 ° C. The carrier is kept in an impregnating solution for 30 minutes. The resulting catalyst is dried at temperatures of 80, 100, 120 ° C for 2 hours at each temperature; then the temperature is increased at a rate of 1 ° C / min to a temperature of 400 ° C, at which the catalyst is calcined for 2 hours in a stream of air. The composition of the finished catalyst, wt. %: 15.0 MoO ₃ ; 2.2 WO ₃ ; 3.2 V ₂ O ₅ ; 4.5 NiO; 0.9 P ₂ O ₅ ; 74.2 Al ₂ O ₃ .

Example 5

For the preparation of a joint impregnation solution of compounds of the active components 10.0 g of MoO ₃ ; 16.1 g of WO ₃ ; 1.2 g of V ₂ O _{5 is} dissolved by heating to 82 ° C 46.7 ml of a 30% solution of H ₂ O ₂ . To the resulting solution was added 0.42 ml of 85% H ₃ PO ₄ , 20.2 g of nickel nitrate Ni (NO ₃ ) ₂ и 6H ₂ O and stirred. The pH of the resulting solution is 2.5. The alumina support weighing 66.7 g is calcined at a temperature of 550 ° C, cooled in a desiccator above a desiccant (calcined anhydrous CaCl ₂ ), kept in vacuum for 30 minutes, then filled with a joint impregnating solution having a temperature of 50 ° C. The carrier is kept in an impregnating solution for 30 minutes. The resulting catalyst is dried at temperatures of 80, 100, 120 ° C for 2 hours at each temperature; then the temperature is increased at a rate of 1 ° C / min to a temperature of 400 ° C, at which the catalyst is calcined for 2 hours in a stream of air. The composition of the finished catalyst, wt. %: 10.0 MoO ₃ ; 16.1 WO ₃ ; 1.2 V ₂ O ₅ ; 5.2 NiO; 0.8 P ₂ O ₅ ; 66.7 Al ₂ O ₃ .

Example 6

To prepare a joint impregnation solution of the compounds of the active components, 1.4 g of MoO ₃ ; 24.8 g of WO _{3 are} dissolved by heating to 82 ° C 47.9 ml of a 30% solution of H ₂ O ₂ . To the resulting solution, 0.33 ml of 85% H ₃ PO ₄ , 17.9 g of nickel nitrate Ni (NO ₃ ) ₂ ⋅ 6H ₂ O are added and mixed. The pH of the resulting solution is 3.5. An alumina carrier weighing 68.5 g is calcined at a temperature of 550 ° C, cooled in a desiccator above a desiccant (calcined anhydrous CaCl ₂ ), kept in vacuum for 30 minutes, then filled with a joint impregnating solution having a temperature of 50 ° C. The carrier is kept in an impregnating solution for 30 minutes. The resulting catalyst is dried at temperatures of 80, 100, 120 ° C for 2 hours at each temperature; then the temperature is increased at a rate of 1 ° C / min to a temperature of 400 ° C, at which the catalyst is calcined for 2 hours in a stream of air. The composition of the finished catalyst, wt. %: 1.4 MoO ₃ ; 24.8 WO ₃ ; 4.6 NiO; 0.7 P ₂ O ₅ ; 68.5 Al ₂ O ₃ .

Claims (9)

1. A method of preparing a catalyst for deep hydrotreating oil fractions, comprising impregnating an alumina carrier with a solution of Group VIII, VI and V compounds of metals, characterized in that a joint impregnating solution of MoO ₃ and / or WO ₃ , not necessarily V ₂ O ₅ , is prepared from 0 , 33 to 0.42 ml of 85% H ₃ PO ₄ , cobalt or nickel nitrate in a 30% solution of H ₂ O ₂ at a pH of the impregnation solution of 2.0-3.5 and a single impregnation of aluminum oxide is carried out with final calcination finished catalyst. 2. The method according to claim 1, characterized in that the molar ratio of Mo (W) / Co (Ni) = 1.60-2.40. 3. The method according to claim 1, characterized in that the molar ratio of MoO ₃ : WO ₃ from 11: 1 to 1:11. 4. The method according to claim 1, characterized in that the molar ratio V / (Mo + W) = 1/11 or 2/10. 5. The method according to claim 1, characterized in that the pH of the impregnating solution is 2.0-3.5. 6. The method according to claim 1, characterized in that the weighed portion of the carrier is carried out at 550 ° C for 1-2 hours. 7. The method according to claim 1, characterized in that the impregnation of the previously evacuated carrier is used at temperatures from 50 to 95 ° C. 8. The method according to claim 1, characterized in that the final calcination of the catalyst is carried out at temperatures of 350-400 ° C. 9. The catalyst for the deep hydrotreating of oil fractions containing MoO ₃ , WO ₃ , CoO or NiO, deposited on alumina by the impregnation method according to claims 1 to 8, characterized in that the catalyst contains from 1.4 to 19.0 wt.% MoO ₃ , from 2.2 to 30.6 wt.% WO ₃ , not necessarily up to 3.2 wt.% V ₂ O ₅ , from 4.1 to 6.2 wt.% CoO or NiO, from 0.7 to 1.6 wt.% Ρ ₂ O ₅ , the rest is Al ₂ O ₃ with a molar ratio of MoO ₃ : WO ₃ of 11: 1 to 1:11, a molar ratio of V: (Mo + W) 1:11 or 2:10 .