Preparation method and application of hydrogenation catalyst

Abstract

The invention provides a preparation method of a hydrogenation catalyst, which comprises the following steps: step 1, mixing a solution of an aluminum precursor and a solution of a part of alkaline precipitant, and controlling the pH value of the system to be 7.0-9.0 by controlling the mixing speed; step 2, adding the solution of the residual alkaline precipitant and the solution of the modified metal salt into the system in the step 1, and controlling the pH value of the system to be 7.0-9.0 by controlling the adding speed; step 3, aging the system obtained in the step 2 to obtain modified alumina dry glue; and step 4, preparing the obtained modified alumina dry glue into a carrier, and then loading an active component to obtain the hydrogenation catalyst. The catalyst provided by the invention has high catalytic activity and selectivity in the hydrodesulfurization process of distillate oil.

Description

Technical Field

[0001] The invention relates to a method for preparing a hydrogenation catalyst. The hydrogenation catalyst is particularly suitable for high-selective hydrogenation desulfurization of catalytic cracking gasoline. Background Art

[0002] The desulfurization activity and selectivity of the catalytic cracking gasoline highly selective hydrodesulfurization catalyst are closely related to the stacking number of MoS2 active phase and the size of the lamellae. By introducing additives such as rare earth elements and alkali metal elements to modify the carrier, the stacking number of MoS2 active phase and the length of the lamellae can be effectively regulated, which is beneficial to improve the degree of metal sulfidation.

[0003] CN102049269B discloses a gasoline selective hydrogenation catalyst and a preparation method thereof, wherein aluminum sulfate and sodium aluminate are first used to form aluminum oxide gel, titanium oxide and / or zirconium oxide are introduced during the pulping process to obtain modified aluminum oxide dry gel powder, and an appropriate amount of carbon and silicon oxide are added during kneading to obtain an aluminum oxide carrier; then, potassium and phosphorus additives are loaded by an impregnation method, and the modified carrier is obtained after drying and roasting; finally, active metals Co and Mo are loaded by an impregnation method. The method enhances the coordination between the carrier and the additives by introducing potassium and phosphorus additives, prevents the loss of alkali metals, inhibits the olefin saturation activity, and maintains high hydrodesulfurization activity, selectivity and stability; however, the preparation process of the method is cumbersome, and the carrier is modified by introducing additives by an impregnation method, and there are problems such as the modified additives are easily accumulated on the surface of the carrier, difficult to enter the pores, and easy to lose during use. Although the loss of potassium is prevented by introducing carbon and the additive phosphorus to play a coordinated role, the carbon must be roasted at 400-550 degrees under anaerobic conditions to prevent the occurrence of phenomena such as catalyst ignition and frying.

[0004] CN103657668A discloses a selective nickel-based hydrogenation catalyst and a preparation method thereof. An alumina carrier is prepared by spraying an alkali metal Li and / or K complex solution on an aluminum hydroxide powder. The aluminum hydroxide powder is fully contacted with a compound containing the alkali metal Li and / or K by kneading, and the introduction of excessive water into the aluminum hydroxide powder can be avoided. While reducing the acidity of the carrier, the electron affinity of the carrier is improved, and the thermal stability, diene hydrogenation selectivity and resistance to impurities such as sulfur and arsenic of the catalyst are improved. Although the method simplifies the catalyst preparation process by a solution spraying method, there are still problems such as the modification aid being easily accumulated on the carrier surface, difficult to enter the pores, and easy to lose during use. At the same time, the spraying is prone to unevenness, and the kneading process will also affect the bonding state of the alumina and the modification aid.

[0005] CN105268449B discloses a hydrogenation catalyst and its application in hydrodeoxygenation. The alumina carrier containing one or more auxiliary metal components selected from Groups IA, IIA and IVB can be prepared by two routes: first, the calcined alumina is mixed with at least one boehmite and / or pseudo-boehmite and water to obtain a mixture, and then subjected to heat treatment. After forming, drying and calcining, the auxiliary metal component is introduced by an impregnation method to obtain the mixture; second, on the basis of route one, the auxiliary metal is introduced during the mixing process to avoid the subsequent impregnation step; this method adds improved auxiliary agents to alumina and boehmite, but requires heating treatment to maintain the alumina crystal phase and high specific surface area and pore volume and other characteristics, effectively alleviating the problems of the conventional impregnation method modified auxiliary agents being easily accumulated on the carrier surface, difficult to enter the pores, and easy to lose during use, but there are still problems such as the metal auxiliary agents agglomerating on the surface of the crystal nucleus, the weak interaction between the metal and the carrier, and the easy loss, and the catalyst preparation process is also relatively cumbersome.

[0006] CN112619632A discloses a modified alumina carrier and a preparation method thereof, wherein firstly, an aluminum source and a precipitant are added to an aqueous solution of one or more precursors of boron, phosphorus or fluorine in parallel to carry out a precipitation reaction to obtain pseudo-boehmite; secondly, the pseudo-boehmite is added to an aqueous solution containing one or more precursors of magnesium oxide, calcium oxide or zirconium oxide and urea to carry out a hydrothermal treatment to obtain modified pseudo-boehmite; then, the modified pseudo-boehmite is mixed with a peptizing agent and an extrusion aid to uniformly extrude into strips, which are then dried and calcined to obtain an alumina carrier; finally, a solution containing VIII The modified alumina carrier is prepared by loading a group metal onto an alumina carrier and performing a sulfidation treatment. The modified alumina carrier is prepared by the method of introducing an acidic regulating agent through a precipitation reaction, introducing a metal agent through a hydrothermal treatment, kneading and extruding the carrier into strips, and loading the metal in four steps, and the preparation process is relatively complicated. Although the metal agent is added to the pseudo-boehmite and hydrothermal treatment is performed, the alumina crystal phase and high specific surface area and pore volume characteristics can be maintained, the metal agent is easily deposited on the surface of the crystal nucleus and is difficult to enter the pores, resulting in weak interaction between the metal and the carrier and easy loss during use.

[0007] CN102989453B discloses a carbon two pre-hydrogenation catalyst and a preparation method. First, KAlO2 or NaAlO2, ZrCl4, and TiCl4 solutions are mixed under stirring conditions, then neutralized with an alkaline solution to generate aluminum zirconium titanium hydroxide coprecipitate, filtered and washed to remove K + 、Na + and Cl -ions, a pore-enlarging agent is added, kneading is performed, drying and calcining are performed to obtain a carrier; the carrier is immersed in a solution containing palladium and silver, filtered, washed, dried and calcined to obtain a catalyst; although this method uses co-precipitation to introduce K or Na, K and Na can change the surface acidity of the catalyst, but when the co-precipitation product is filtered, it will be washed to less than 0.5%. Due to the low content, its effect on the acidity of the catalyst is limited, and the effect on the modulation of the interaction force between the metal and the carrier is not significant; at the same time, in order to ensure the content of K or Na, multiple washings are likely to result in the generation of more waste liquid, which is not conducive to environmentally friendly production.

[0008] It can be seen that the loading method is often used to modify the carrier additive, but the preparation process of this method is cumbersome and it is easy to cause the modified additive to accumulate on the carrier surface, making it difficult to enter the catalyst pores, affecting the control effect of the modified additive on the metal active phase. At the same time, it is easy to lose during use, making it difficult to maintain the stability of the catalyst for a long time. In the process of synthesizing the carrier from pseudo-boehmite by co-precipitation, potassium carbonate is sometimes used as a co-precipitant, but in order to control the metal cation K + The content of K is too low, and multiple washings are required to produce a large amount of waste liquid, which is not conducive to environmental protection. At the same time, it will also cause the K content to be too low, and the effect of adjusting the force between the metal and the carrier is not significant. In addition, the pore structure of the hydrogenation catalyst prepared by the co-precipitation method in the prior art is not ideal, resulting in weak desulfurization activity and poor selectivity of the hydrogenation catalyst. Summary of the invention

[0009] The main purpose of the present invention is to provide a preparation method of a hydrogenation catalyst and its application, so as to overcome the defects of the prior art hydrogenation catalyst in that the pore structure is not ideal and thus the hydrodesulfurization activity and selectivity are not high.

[0010] In order to achieve the above object, the present invention provides a method for preparing a hydrogenation catalyst, comprising the following steps:

[0011] Step 1, mixing a solution of an aluminum precursor and a solution of a portion of an alkaline precipitant, and controlling the mixing speed so that the pH value of the system is controlled at 7.0 to 9.0;

[0012] Step 2, adding the remaining alkaline precipitant solution and the modified metal salt solution into the system of step 1, and controlling the pH value of the system to be between 7.0 and 9.0 by controlling the adding speed;

[0013] Step 3, aging the system obtained in step 2 to obtain a modified alumina dry glue;

[0014] Step 4, preparing the obtained modified alumina dry gel into a carrier, and then loading the active component to obtain a hydrogenation catalyst.

[0015] The preparation method of the hydrogenation catalyst of the present invention, wherein the alkaline precipitant is one or more of potassium carbonate, potassium hydroxide and potassium bicarbonate; after the system obtained in step 2 is aged, it also includes the steps of filtering and directly drying the obtained filter cake to obtain modified alumina dry glue.

[0016] In the method for preparing the hydrogenation catalyst of the present invention, the addition amount of part of the alkaline precipitant and the remaining alkaline precipitant is such that the mass content of K in the obtained hydrogenation catalyst calculated as potassium oxide is 2% to 4%.

[0017] The preparation method of the hydrogenation catalyst of the present invention, wherein the aluminum precursor is a soluble aluminum salt, the modified metal salt is at least one of a zirconium salt, a lanthanum salt, and a copper salt; the added amount of the modified metal salt is such that the mass content of the modified metal in the obtained hydrogenation catalyst is 0.1%-5% in terms of modified metal oxide.

[0018] The preparation method of the hydrogenation catalyst described in the present invention, wherein the aluminum precursor is at least one of aluminum nitrate and aluminum sulfate; the modified metal salt is at least one of zirconium nitrate, lanthanum nitrate, copper nitrate, zirconium acetate, lanthanum acetate, and copper acetate.

[0019] The method for preparing the hydrogenation catalyst of the present invention, wherein in step 1, the mixing temperature of the aluminum precursor solution and the solution of part of the alkaline precipitant is 20-80° C., and the mixing time is 30-50 min.

[0020] In the method for preparing the hydrogenation catalyst of the present invention, the addition time of the solution of the remaining alkaline precipitant and the solution of the modified metal salt is 5-15 minutes, and the temperature of the system is controlled at 20-80°C.

[0021] The preparation method of the hydrogenation catalyst of the present invention comprises the following steps: the aging temperature is 60-100°C, and the aging time is 60-180 minutes; the filter cake is dried at 120-180°C, and the drying time is 60-120 minutes.

[0022] The preparation method of the hydrogenation catalyst described in the present invention, wherein the step of preparing the modified alumina dry glue into a carrier is: the modified alumina dry glue is kneaded with a binder, a pore expander and an extrusion aid, extruded into strips, and then dried and calcined to obtain the carrier; the binder is one or more of silica sol, nitric acid, acetic acid, and malic acid, the pore expander is one or more of citric acid, yeast, methyl cellulose, and hydroxypropyl methyl cellulose, and the extrusion aid is one or more of sesbania powder, starch and citric acid; the dry basis mass ratio of the binder to the modified alumina dry glue is 0.02-0.05:1, the dry basis mass ratio of the pore expander to the modified alumina dry glue is 0.01-0.1:1, and the dry basis mass ratio of the extrusion aid to the modified alumina dry glue is 0.01-0.05:1.

[0023] The method for preparing the hydrogenation catalyst of the present invention, wherein the active component is at least one of the elements of Group VIII and Group VIB; in the hydrogenation catalyst, the mass content of the active component in terms of metal oxide is 9%-20%.

[0024] The preparation method of the hydrogenation catalyst of the present invention, wherein the active component is Mo and at least one of Co and Ni; in the hydrogenation catalyst, the content of Mo calculated as MoO3 is 8.0% to 16.0%, and the content of Co and / or Ni calculated as oxides is 1.0% to 4.0%.

[0025] In order to achieve the above object, the present invention also provides the use of the hydrogenation catalyst obtained by the above preparation method in the hydrodesulfurization of distillate oil.

[0026] Beneficial effects of the present invention:

[0027] (1) The present invention first mixes an aluminum precursor with a portion of an alkaline precipitant to precipitate aluminum, and then adds the remaining alkaline precipitant and a modified metal salt to precipitate the modified metal. By controlling the pH value of the precipitation system, it is not only possible to ensure that the aluminum oxide grains are uniform, the structure is complete, and there is less agglomeration, but also that the rich pore structure of aluminum oxide can be utilized to achieve in-situ modification of aluminum oxide by the modified metal, thereby prompting the modified metal to enter the aluminum oxide pores, effectively adjusting the interaction force between the modified metal and the carrier, and avoiding the loss of the modified metal during use. At the same time, the sulfurization degree of the active metal component is improved, and the number of MoS2 active centers is increased, which helps to improve the desulfurization activity of the hydrogenation catalyst.

[0028] (2) Furthermore, the present invention uses potassium salt as an alkaline precipitant, and K +As a precursor of modified metal, it achieves the dual purposes of precipitation and metal modification. In addition, after aging of the system, the filter cake is directly dried without washing to obtain modified alumina dry gel. The potassium retained on the alumina can modify the alumina in situ. The characteristics of potassium as an electronic auxiliary agent to donate electrons and as an alkaline auxiliary agent to regulate the acid distribution and pore distribution of the carrier are utilized to make the alumina have a concentrated pore structure (pores of 10-20nm account for 60-80%), while weakening the interaction between the carrier and the active component, which helps to improve the desulfurization selectivity of the catalyst. It can also avoid the generation of a large amount of waste liquid caused by washing. DETAILED DESCRIPTION

[0029] The technical scheme of the present invention is described in detail below. The following implementation modes are implemented on the premise of the technical scheme of the present invention, and a detailed implementation process is given. However, the protection scope of the present invention is not limited to the following implementation modes. The structures or experimental methods of specific conditions are not specified in the following implementation modes, and generally conventional conditions are followed.

[0030] The present invention provides a method for preparing a hydrogenation catalyst, comprising the following steps:

[0031] Step 1, mixing a solution of an aluminum precursor and a solution of a portion of an alkaline precipitant, and controlling the mixing speed so that the pH value of the system is controlled at 7.0 to 9.0;

[0032] Step 2, adding the remaining alkaline precipitant solution and the modified metal salt solution into the system of step 1, and controlling the pH value of the system to be between 7.0 and 9.0 by controlling the adding speed;

[0033] Step 3, aging the system obtained in step 2 to obtain a modified alumina dry glue;

[0034] Step 4, preparing the obtained modified alumina dry gel into a carrier, and then loading the active component to obtain a hydrogenation catalyst.

[0035] The present invention first mixes an aluminum precursor with a part of the alkaline precipitant to precipitate aluminum, and then adds the remaining alkaline precipitant and the modified metal salt to precipitate the modified metal. By controlling the pH value of the precipitation system, it can not only ensure that the aluminum oxide grains are uniform, the structure is complete, and the agglomeration is less, but also the rich pore structure of the aluminum oxide can be utilized to achieve in-situ modification of the aluminum oxide by the modified metal, so as to promote the modified metal to enter the aluminum oxide pores, effectively adjust the interaction force between the modified metal and the carrier, avoid the loss of the modified metal during use, and at the same time improve the sulfurization degree of the active metal component, increase the number of MoS2 active centers, and help to improve the desulfurization activity of the hydrogenation catalyst.

[0036] The hydrogenation catalyst of the invention is suitable for distillate oil hydrodesulfurization, and is particularly suitable for catalytic cracking gasoline high-selectivity hydrodesulfurization.

[0037] In one embodiment, the aluminum precursor of the present invention is a soluble aluminum salt, and more specifically, can be a soluble inorganic aluminum salt, such as at least one of aluminum nitrate and aluminum sulfate.

[0038] In one embodiment, the alkaline precipitant of the present invention has carbonate ions or bicarbonate ions, preferably, one or more of potassium carbonate, potassium hydroxide, and potassium bicarbonate. The sum of the amount of the partial alkaline precipitant and the remaining alkaline precipitant of the present invention is the total amount of the alkaline precipitant added. The present invention does not particularly limit the ratio of the partial alkaline precipitant and the remaining alkaline precipitant, as long as the pH value of the system can be controlled within the range of 7.0 to 9.0, and the amount of the partial alkaline precipitant and the remaining alkaline precipitant added is such that the mass content of K in terms of potassium oxide in the obtained hydrogenation catalyst is 2% to 4%.

[0039] In one embodiment, the modified metal salt of the present invention is at least one of a zirconium salt, a lanthanum salt, and a copper salt, for example, at least one of a zirconium nitrate, a lanthanum nitrate, a copper nitrate, a zirconium acetate, a lanthanum acetate, and a copper acetate. The amount of the modified metal salt added is such that the mass content of the modified metal in the obtained hydrogenation catalyst is 0.1%-5% in terms of the modified metal oxide.

[0040] In one embodiment, in step 1, the solution of the aluminum precursor and the solution of part of the alkaline precipitant are mixed to undergo a precipitation reaction, the temperature of the mixed solution is controlled to be 20-80°C (i.e., the temperature of the precipitation reaction is 20-80°C), preferably 40-80°C, and the mixing time is 30-50 minutes. In step 2, after the solution of the remaining alkaline precipitant and the solution of the modified metal salt are added to the system of step 1, the alkaline precipitant and the modified metal salt will undergo a precipitation reaction, the temperature of the mixed system is controlled to be 20-80°C (i.e., the temperature of the precipitation reaction is 20-80°C), preferably 40-80°C, and the time for adding the two materials is 5-15 minutes. In this way, the uniformity of the grains of the obtained aluminum oxide can be ensured.

[0041] After the solution of the aluminum precursor of the present invention is mixed with the solution of part of the alkaline precipitant, the aluminum precursor begins to precipitate under the action of the alkaline precipitant; after the aluminum precipitation is completed, the solution of the remaining alkaline precipitant and the solution of the modified metal salt are added, and the modified metal begins to precipitate. After the modified metal precipitation is completed, the reaction system is aged and filtered, and the obtained filter cake is directly dried to obtain the modified alumina dry glue.

[0042] The present invention adopts potassium salt as an alkaline precipitant, and after the system is aged, the filter is carried out, and the obtained filter cake is directly dried without washing to obtain a modified alumina dry gel. The potassium retained on the alumina can be used as a precursor of the modified metal to perform in-situ modification on the alumina. The characteristics of potassium as an electronic auxiliary agent to donate electrons and as an alkaline auxiliary agent to regulate the acid distribution and pore distribution of the carrier are utilized to make the alumina have a concentrated pore structure (pores of 10-20 nm account for 60-80%), while weakening the interaction between the carrier and the active component, which is helpful to improve the desulfurization selectivity of the catalyst; and the generation of a large amount of waste liquid caused by washing can be avoided.

[0043] In one embodiment, in step 3, the system obtained in step 2 is aged at a temperature of 60 to 100° C., preferably 60 to 70° C., and the aging time is 60 to 180 min, preferably 100 to 150 min. After aging, the system is filtered, and the filter cake is directly dried without washing at a temperature of 120 to 180° C., preferably 120 to 150° C., and the drying time is 60 to 120 min, preferably 90 to 120 min, to obtain a modified alumina dry glue.

[0044] Step 4 is: preparing the obtained modified alumina dry gel into a carrier, and then loading the active component to obtain a hydrogenation catalyst.

[0045] The present invention does not particularly limit the specific method of preparing the modified alumina dry glue into a carrier. In one embodiment, the modified alumina dry glue of the present invention is kneaded and extruded with a binder, a pore expander and an extrusion aid, and then dried and calcined to obtain a modified alumina carrier. In another embodiment, the binder is one or more of silica sol, nitric acid, acetic acid, malic acid, preferably silica sol and acetic acid, the pore expander is one or more of citric acid, yeast, methyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, for example, has a viscosity of 200,000, preferably citric acid, yeast, methyl cellulose (200,000 viscosity), and the extrusion aid is one or more of sesbania powder, starch and citric acid; the binder and the modified alumina dry glue dry basis mass ratio is 0.02-0.05:1, preferably 0.03-0.05:1, the pore expander and the modified alumina dry glue dry basis mass ratio is 0.01-0.1:1, preferably 0.03-0.06:1, and the extrusion aid and the modified alumina dry glue dry basis mass ratio is 0.01-0.05:1, preferably 0.03-0.04:1. The present invention does not particularly limit the drying temperature and calcination temperature when preparing the modified alumina carrier, and conventional technical means in the art can be used.

[0046] In the carrier extrusion process of the present invention, when the binder is silica sol, since silica sol has the function of a modification aid, the purposes of carrier extrusion and silicon modification can be achieved simultaneously, and the carrier acid distribution is adjusted by the introduction of silicon, the B acid content is increased, and the desulfurization activity and selectivity of the catalyst are promoted.

[0047] The present invention does not particularly limit the method of loading the active component on the carrier, for example, an impregnation method is used. In one embodiment, the active component is at least one of the elements of Group VIII and Group VIB, the precursor of the active component is dissolved in a composite complexing agent to form a stable active component complexing solution, and then the carrier prepared above is impregnated, for example, equal volume impregnation, dried, and calcined to obtain a hydrogenation catalyst.

[0048] In another embodiment, the composite complexing agent is a mixture of one or more of phosphoric acid, tartaric acid, malic acid, oxalic acid, nitrilotriacetic acid, EDTA, EDTP and citric acid, preferably a mixture of one or more of phosphoric acid, oxalic acid, nitrilotriacetic acid and citric acid, and the pH value of the solution is 0.1-5.0, preferably 1.0-3.0.

[0049] In another embodiment, the Group VIII element is cobalt or nickel, and the Group VIB element is molybdenum; the cobalt precursor is a cobalt salt, such as one or more of cobalt nitrate, basic carbonate, acetate or sulfate; the nickel precursor is a nickel salt, such as one or more of nickel nitrate, basic carbonate, acetate or sulfate; the molybdenum precursor is a molybdenum salt, such as one or more of ammonium heptamolybdate, ammonium tetramolybdate, ammonium dimolybdate, and molybdenum oxide.

[0050] In one embodiment, the active component is impregnated into the carrier of the present invention by vacuum impregnation, for example, with an impregnation pressure of 0.05-0.1 MPa, preferably 0.07-0.09 MPa, for 4-8 h, preferably 4-6 h, followed by drying at 100-150°C for 3-6 h, preferably drying at 100-120°C for 3-6 h, and calcining at 400-600°C for 3-6 h.

[0051] In the hydrogenation catalyst of the present invention, the mass content of the active component calculated as metal oxidant is 9-20%. In one embodiment, the content of Mo calculated as MoO3 is 8.0% to 16.0%, and the content of Co and / or Ni calculated as oxide is 1.0% to 4.0%.

[0052] In one embodiment, the catalyst carrier of the present invention is composed of silicon oxide (for example, derived from a binder) and modified aluminum oxide (wherein the modification includes modification of aluminum oxide by potassium oxide, and modification of aluminum oxide by at least one of zirconium oxide, lanthanum oxide, and copper oxide); the active components of the catalyst of the present invention are composed of Mo oxides, and Co and / or Ni oxides. Based on 100% by mass of the catalyst, the catalyst includes: a MoO3 content of 8.0% to 16.0%, preferably 10.0% to 13.0%, a CoO or NiO content of 1.0% to 4.0%, preferably 2.5% to 3.5%, a silicon oxide content of 0.1 to 1.5%, preferably 0.5 to 1.0%, a potassium oxide content of 2 to 4%, preferably 2.0 to 3.5%, a zirconium oxide content of 0.1 to 2%, preferably 0.5 to 1.5%, a lanthanum oxide content of 0.1 to 1%, preferably 0.3 to 0.8%, a copper oxide content of 0.1 to 2%, preferably 0.3 to 0.8%, and the remainder is an aluminum oxide carrier.

[0053] The catalyst prepared by the method of the present invention has the following physical properties: bulk density 0.5-0.8 g / ml, preferably 0.6-0.7 g / ml, pore volume 0.3-0.8 ml / g, preferably 0.4-0.6 ml / g, specific surface area 150-300 m 2 / g, preferably 170-220m 2 / g, with an average pore size of 7-16nm, preferably 8-14nm, wherein the volume percentage of pores with 10-20nm in the total pore volume is 50-80%, preferably 60-80%.

[0054] The hydrogenation catalyst prepared by the present invention needs to be vulcanized before use. In one embodiment, a programmed temperature rise vulcanization method can be adopted. The vulcanization method can be wet vulcanization or dry vulcanization. The vulcanization conditions are: heating rate 10-40℃ / h, 150℃ stay for 2h, 230℃ stay for 8h, 320℃ stay for 6h, volume space velocity 1-3h -1 , hydrogen-oil ratio 100:1-500:1, pressure 1.0-3.0MPa; process parameters for hydrogenation catalyst application are, for example: hydrogen pressure 1.0-3.0MPa, temperature 220-300°C, space velocity 1.0-4.0h -1 , hydrogen-to-oil ratio of 100:1-500:1, for example, used in the desulfurization process of petroleum processing.

[0055] In another embodiment, the vulcanization conditions are: heating rate 20-30°C / h, 150°C for 2h, 230°C for 8h, 320°C for 6h, volume space velocity 1-3h -1 , hydrogen-oil ratio 200:1-400:1, pressure 1.0-3.0MPa; catalyst application process parameters: hydrogen pressure 1.0-3.0MPa, temperature 220-300℃, space velocity 2.0-3.0h-1 , hydrogen-to-oil ratio 200:1-400:1, for example, used in the desulfurization process of petroleum processing.

[0056] The catalyst prepared by the method of the present invention has a concentrated pore structure, with pores of 10-20 nm accounting for 60-80%, a desulfurization rate of catalytic heavy gasoline being ≥90%, and a desulfurization selectivity being ≥70%. Compared with conventional catalyst preparation methods, while achieving green and environmentally friendly production, the catalyst has a more concentrated pore structure and a higher desulfurization rate and desulfurization selectivity, can meet the needs of deep desulfurization of clean gasoline of National VI standard, and has less octane number loss.

[0057] The technical solutions of the present invention are further described below by way of examples, but the technical solutions of the present invention are not limited to the following examples.

[0058] Example 1

[0059] (1) Preparation of aluminum hydroxide dry gel

[0060] Weigh 374g of aluminum nitrate nonahydrate and dissolve it in deionized water, make the volume to 1L, and the solution concentration is Al2O351g / L; weigh 830g of potassium carbonate and dissolve it in deionized water, make the volume to 4.0L, and the solution concentration is K2O142g / L, as a precipitant; weigh 2.3g of zirconium nitrate, 0.97g of lanthanum nitrate, and 1.1g of copper nitrate and dissolve them in 100g of deionized water to prepare a modification additive solution. First add bottom water to the reactor, preheat to 60°C, add 1L aluminum nitrate solution and 1.45L potassium carbonate solution in parallel under stirring, adjust the flow rate of solution addition, control the pH value of the slurry in the reactor to 7, and add the feed time to 40min; after the addition is completed, continue to add the mixed modification auxiliary solution of zirconium nitrate and lanthanum nitrate and 145ml potassium carbonate solution in parallel under stirring, adjust the flow rate of solution addition, control the pH value of the slurry in the reactor to 7, and add the feed time to 6min; after the addition is completed, stand and age for 120min at this temperature and pH value. After the aging is completed, filter the slurry, and dry the obtained filter cake at 150°C for 120min to obtain aluminum hydroxide dry glue.

[0061] (2) Vector preparation

[0062] Weigh 100g of aluminum hydroxide dry gel (dry basis 71%), 2.1g of sesbania powder, and 1.4g of methyl cellulose (viscosity of 200,000) and add them into a kneader, and knead for 10 minutes; add 2.5g of silica sol, 2.1g of acetic acid, and 1.4g of citric acid in turn into 60g of deionized water, stir until dissolved, and slowly add the obtained solution into the kneader and knead for 30 minutes. The mixed material is extruded, dried at 120°C, and calcined at 550°C for 4 hours to obtain carrier Z1.

[0063] (3) Catalyst preparation

[0064] Weigh 8.0g of ammonium heptamolybdate, 2.0g of citric acid, and 1.0g of nitrilotriacetic acid, dissolve in deionized water, stir evenly to obtain a clear solution, add 6.9g of cobalt nitrate and stir until dissolved, dilute to 40ml with deionized water, and the pH value is 2.0-3.0; weigh 50g of carrier Z1 for equal volume impregnation, vacuum impregnation pressure 0.08MPa, stand for 6 hours, dry at 120°C for 4h, and calcine at 500°C for 4h to obtain catalyst A1.

[0065] Example 2

[0066] (1) Preparation of aluminum hydroxide dry gel

[0067] The preparation method of aluminum hydroxide dry gel is the same as that in Example 1, except that the pH value is controlled to be 8 during the precipitation reaction.

[0068] (2) Vector preparation

[0069] The preparation method of carrier Z2 is the same as that of carrier Z1, except that 2.5 g of silica sol, 2.3 g of acetic acid and 1.4 g of citric acid are added to 62 g of deionized water in sequence, followed by mixing, kneading, extruding, drying and calcining.

[0070] (3) Catalyst preparation

[0071] The metal impregnation method of catalyst A2 is the same as that of A1, the only difference is that the volume is fixed to 39 ml with deionized water, and then impregnation, drying and calcination are carried out.

[0072] Example 3

[0073] (1) Preparation of aluminum hydroxide dry gel

[0074] The preparation method of aluminum hydroxide dry gel is the same as that in Example 1, except that the pH value is controlled to be 9 during the precipitation reaction.

[0075] (2) Vector preparation

[0076] The preparation method of carrier Z3 is the same as that of carrier Z1, except that 2.5 g of silica sol, 2.4 g of acetic acid and 1.5 g of citric acid are added to 62 g of deionized water in sequence, followed by mixing, kneading, extruding, drying and calcining.

[0077] (3) Catalyst preparation

[0078] The metal impregnation method of catalyst A3 is the same as that of A1, the only difference is that the volume is fixed to 37 ml with deionized water, and then impregnation, drying and calcination are carried out.

[0079] Example 4

[0080] (1) Preparation of aluminum hydroxide dry gel

[0081] The preparation method of aluminum hydroxide dry glue is the same as that in Example 2, except that bottom water is first added to the reactor and preheated to 20°C, the addition time of aluminum nitrate solution and potassium carbonate solution is 50min, and the filter cake obtained by filtering the slurry is dried at 120°C for 120min to obtain aluminum hydroxide dry glue.

[0082] (2) Vector preparation

[0083] The preparation method of carrier Z4 is the same as that of carrier Z2, the only difference being that 2.5 g of silica sol, 2.7 g of acetic acid and 1.5 g of citric acid are sequentially added into 62 g of deionized water, followed by mixing, kneading, extruding, drying and calcining.

[0084] (3) Catalyst preparation

[0085] The metal impregnation method of catalyst A4 is the same as that of A2.

[0086] Example 5

[0087] (1) Preparation of aluminum hydroxide dry gel

[0088] The preparation method of aluminum hydroxide dry glue is the same as that in Example 2, except that bottom water is first added to the reactor and preheated to 80°C, the addition time of aluminum nitrate solution and potassium carbonate solution is 30 minutes, and the filter cake obtained by filtering the slurry is dried at 180°C for 60 minutes to obtain aluminum hydroxide dry glue.

[0089] (2) Vector preparation

[0090] The preparation method of carrier Z5 is the same as that of carrier Z2, except that 2.5 g silica sol, 2.5 g acetic acid, and 1.5 g citric acid are sequentially added to 62 g deionized water, followed by mixing, kneading, extruding, drying, and calcining.

[0091] (3) Catalyst preparation

[0092] The metal impregnation method of catalyst A5 is the same as that of A2.

[0093] Example 6

[0094] (1) Preparation of aluminum hydroxide dry gel

[0095] The preparation method of aluminum hydroxide dry glue is the same as that in Example 2, the only difference being that the slurry aging temperature in the reactor is 100° C. and the aging is performed for 60 min.

[0096] (2) Vector preparation

[0097] The preparation method of carrier Z6 is the same as that of carrier Z2, the only difference being that 2.5 g of silica sol, 2.5 g of acetic acid and 1.5 g of citric acid are sequentially added into 62 g of deionized water, followed by mixing, kneading, extruding, drying and calcining.

[0098] (3) Catalyst preparation

[0099] The metal impregnation method of catalyst A6 is the same as that of A2.

[0100] Example 7

[0101] (1) Preparation of aluminum hydroxide dry gel

[0102] The preparation method of aluminum hydroxide dry glue is the same as that in Example 2, the only difference being that the slurry in the reactor is left to age for 180 min.

[0103] (2) Vector preparation

[0104] The preparation method of carrier Z6 is the same as that of carrier Z2, the only difference being that 2.5 g of silica sol, 2.4 g of acetic acid and 1.5 g of citric acid are sequentially added into 62 g of deionized water, followed by mixing, kneading, extruding, drying and calcining.

[0105] (3) Catalyst preparation

[0106] The metal impregnation method of catalyst A7 is the same as that of A2.

[0107] Example 8

[0108] (1) Preparation of aluminum hydroxide dry gel

[0109] The preparation method of aluminum hydroxide dry glue is the same as that in Example 2.

[0110] (2) Vector preparation

[0111] The preparation method of carrier Z8 is the same as that of carrier Z2, the only difference being that 0.3 g silica sol, 3.3 g acetic acid and 1.6 g citric acid are sequentially added into 62 g deionized water, followed by mixing, kneading, extruding, drying and calcining.

[0112] (3) Catalyst preparation

[0113] The metal impregnation method of catalyst A8 is the same as that of A2, the only difference is that the volume is fixed to 40 ml with deionized water, and then impregnation, drying and calcination are carried out.

[0114] Example 9

[0115] (1) Preparation of aluminum hydroxide dry gel

[0116] The preparation method of aluminum hydroxide dry glue is the same as that in Example 2.

[0117] (2) Vector preparation

[0118] The preparation method of carrier Z9 is the same as that of carrier Z2, the only difference being that 4.2 g of silica sol, 1.3 g of acetic acid and 1.2 g of citric acid are sequentially added into 62 g of deionized water, followed by mixing, kneading, extruding, drying and calcining.

[0119] (3) Catalyst preparation

[0120] The metal impregnation method of catalyst A9 is the same as that of A2, the only difference is that the volume is fixed to 40 ml with deionized water, and then impregnation, drying and calcination are carried out.

[0121] Example 10

[0122] (1) Preparation of aluminum hydroxide dry gel

[0123] Weigh 374g of aluminum nitrate nonahydrate and dissolve it in deionized water, dilute to 1L, and the solution concentration is Al2O351g / L; weigh 830g of potassium carbonate and dissolve it in deionized water, dilute to 4.0L, and the solution concentration is K2O142g / L as a precipitant; weigh 0.5g of zirconium nitrate, 0.2g of lanthanum nitrate, and 0.2g of copper nitrate and dissolve them in 100g of deionized water to prepare a modification auxiliary solution. The other steps are the same as in Example 2, and the pH value is controlled to be 8 during the precipitation reaction.

[0124] (2) Vector preparation

[0125] The preparation method of carrier Z10 is the same as that of carrier Z2, except that 2.5 g of silica sol, 1.9 g of acetic acid and 1.4 g of citric acid are added to 60 g of deionized water in sequence, followed by mixing, kneading, extruding, drying and calcining.

[0126] (3) Catalyst preparation

[0127] The metal impregnation method of catalyst A10 is the same as that of A2, the only difference is that the volume is fixed to 41 ml with deionized water, and then impregnation, drying and calcination are carried out.

[0128] Embodiment 11

[0129] (1) Preparation of aluminum hydroxide dry gel

[0130] Weigh 374g of aluminum nitrate nonahydrate and dissolve it in deionized water, dilute to 1L, and the solution concentration is Al2O351g / L; weigh 830g of potassium carbonate and dissolve it in deionized water, dilute to 4.0L, and the solution concentration is K2O142g / L as a precipitant; weigh 4.7g of zirconium nitrate, 1.9g of lanthanum nitrate, and 4.4g of copper nitrate and dissolve them in 100g of deionized water to prepare a modification auxiliary solution. The other steps are the same as in Example 2, and the pH value is controlled to be 8 during the precipitation reaction.

[0131] (2) Vector preparation

[0132] The preparation method of carrier Z11 is the same as that of carrier Z2 in Example 2, except that 2.5 g of silica sol, 2.5 g of acetic acid and 1.4 g of citric acid are added to 63 g of deionized water in sequence, followed by mixing, kneading, extruding, drying and calcining.

[0133] (3) Catalyst preparation

[0134] The metal impregnation method of catalyst A11 is the same as that of catalyst A2 in Example 2, except that the volume is fixed to 37 ml with deionized water, followed by impregnation, drying and calcination.

[0135] Example 12

[0136] (1) Preparation of aluminum hydroxide dry gel

[0137] The preparation method of aluminum hydroxide dry glue is the same as that in Example 2.

[0138] (2) Vector preparation

[0139] The preparation method of carrier Z12 is the same as that of carrier Z2 in Example 2.

[0140] (3) Catalyst preparation

[0141] Weigh 5.5g of ammonium heptamolybdate, 1.7g of citric acid, and 1.0g of nitrilotriacetic acid, dissolve in deionized water, stir evenly to obtain a clear solution, add 2.2g of cobalt nitrate and stir until dissolved, dilute to 39ml with deionized water, and the pH value is 2.0-3.0; weigh 50g of carrier Z6 for equal volume impregnation, vacuum impregnation pressure of 0.08MPa, stand for 6 hours, dry at 120℃ for 4h, and calcine at 500℃ for 4h to obtain catalyst 12.

[0142] Embodiment 13

[0143] (1) Preparation of aluminum hydroxide dry gel

[0144] The preparation method of aluminum hydroxide dry glue is the same as that in Example 2.

[0145] (2) Vector preparation

[0146] The preparation method of carrier Z13 is the same as that of carrier Z2 in Example 2.

[0147] (3) Catalyst preparation

[0148] A two-step impregnation method was used: first, 7.2 g of ammonium heptamolybdate, 1.8 g of citric acid, and 1.0 g of nitrilotriacetic acid were weighed, dissolved in deionized water, and stirred evenly to obtain a clear solution. Then, 6.8 g of cobalt nitrate was added and stirred until dissolved. The volume was adjusted to 39 ml with deionized water, and the pH value was 2.0-3.0. 50 g of carrier Z2 was weighed for equal volume impregnation, the vacuum impregnation pressure was 0.08 MPa, and the mixture was allowed to stand for 6 hours, dried at 120°C for 4 hours, and calcined at 500°C for 4 hours to obtain a single impregnation catalyst. Weigh 4.0g of ammonium heptamolybdate, 1.4g of citric acid, and 0.8g of nitrilotriacetic acid, dissolve in deionized water, stir evenly to obtain a clear solution, add 2.1g of cobalt nitrate and stir until dissolved, dilute to 31ml with deionized water, and the pH value is 2.0-3.0; weigh 50g of one-step impregnation carrier for equal volume impregnation, vacuum impregnation pressure of 0.08MPa, stand for 6 hours, dry at 120℃ for 4h, and calcine at 500℃ for 4h to obtain catalyst A13.

[0149] Embodiment 14

[0150] (1) Preparation of aluminum hydroxide dry gel

[0151] The preparation method of aluminum hydroxide dry gel is the same as that in Example 2, except that 673 g of potassium hydroxide is weighed and dissolved in deionized water and the volume is fixed to 4.0 L as a precipitant. The other steps are the same as those in Example 2.

[0152] (2) Vector preparation

[0153] The preparation method of carrier Z14 is the same as that of carrier Z2, the only difference being that 2.5 g of silica sol, 2.1 g of acetic acid and 1.5 g of citric acid are sequentially added into 62 g of deionized water, followed by mixing, kneading, extruding, drying and calcining.

[0154] (3) Catalyst preparation

[0155] The metal impregnation method of catalyst A14 is the same as that of A2.

[0156] Embodiment 15

[0157] (1) Preparation of aluminum hydroxide dry gel

[0158] The preparation method of aluminum hydroxide dry gel is the same as that in Example 2, except that 1202 g of potassium bicarbonate is weighed and dissolved in deionized water and the volume is fixed to 4.0 L as a precipitant. The other steps are the same as those in Example 2.

[0159] (2) Vector preparation

[0160] The preparation method of carrier Z15 is the same as that of carrier Z2, the only difference being that 2.5 g of silica sol, 2.2 g of acetic acid and 1.5 g of citric acid are sequentially added into 62 g of deionized water, followed by mixing, kneading, extruding, drying and calcining.

[0161] (3) Catalyst preparation

[0162] The metal impregnation method of catalyst A15 is the same as that of A2.

[0163] Comparative Example 1

[0164] (1) Preparation of aluminum hydroxide dry gel

[0165] The preparation method of aluminum hydroxide dry gel is similar to that of Example 2, except that the slurry is filtered after aging, and the filter cake is washed with deionized water several times to remove the precipitant metal cation K. + , wash until the filtrate is neutral, dry the filter cake at 150°C for 120 min to obtain aluminum hydroxide dry gel.

[0166] (2) Vector preparation

[0167] The preparation method of carrier D1 is the same as that of carrier Z2.

[0168] (3) Catalyst preparation

[0169] The metal impregnation method of catalyst D1 is the same as that of catalyst A2 in Example 2.

[0170] Comparative Example 2

[0171] (1) Preparation of aluminum hydroxide dry gel

[0172] The preparation method of aluminum hydroxide dry gel is similar to that of Example 2, the only difference being that aluminum nitrate solution, potassium carbonate solution and modification aid solution are added in parallel for co-precipitation, and the rest is the same as that of Example 2 to obtain aluminum hydroxide dry gel.

[0173] (2) Vector preparation

[0174] The method for carrier D2 is the same as that for carrier Z2 in Example 2.

[0175] (3) Catalyst preparation

[0176] The metal impregnation method of catalyst D2 is the same as that of catalyst A2 in Example 2.

[0177] The physicochemical properties of the catalysts obtained in the above examples and comparative examples are shown in Table 1.

[0178]

[0179]

[0180]

[0181] As shown in Table 2, the hydroprocessing catalyst prepared by the method of the present invention has significantly better desulfurization activity and selectivity than the catalyst prepared in the comparative example in the selective desulfurization process, meets the high-selective deep desulfurization of clean gasoline in accordance with the National VI standard, and can reduce the octane number loss. Among them, Examples 1 to 3 achieve the modulation of K content and the modification of pore structure by adjusting the pH value. As the precipitation pH value increases, the K content on the catalyst gradually increases, and the volume percentage of the pore volume of 10-20nm in the total pore volume shows a trend of first increasing and then decreasing; Examples 2, 4, 6, and 7 adjust the catalyst pore structure by adjusting the precipitation temperature and time of the system, the slurry aging temperature, and the drying temperature; Examples 2, 8, and 9 increase the surface acidity of the catalyst by adjusting the added content of silica sol. As the silicon content increases, the catalyst desulfurization activity gradually increases, while the desulfurization selectivity first increases and then decreases; Examples 2, 10, and 11 achieve the modification of pore structure and the regulation of the interaction between metal and carrier by adjusting the content of the modifying agent; Examples 2, 12, and 13 achieve the regulation of active phase structure by adjusting the content of metal active components. Comparative Example 1 Compared with Example 2, in the preparation process of aluminum hydroxide dry gel, the filter cake was washed several times to remove K + In the process, in addition to the disadvantage of generating a large amount of waste liquid that is not conducive to environmental protection, the prepared catalyst lacks the modification effect of the modification agent K, and the 10-20nm pore ratio is low, resulting in a significant decrease in the desulfurization activity and selectivity of the catalyst; Comparative Example 2 Compared with Example 2, in the preparation process of aluminum hydroxide dry gel, aluminum nitrate solution, potassium carbonate solution and modification agent solution are co-precipitated simultaneously. Due to the competitive precipitation between the aluminum source and the modification agent, the modification agent is easy to block the alumina pores after precipitation, and the 10-20nm pore ratio is low, which is not conducive to the effective utilization of the active components, resulting in a decrease in the desulfurization activity and selectivity of the catalyst.

[0182] The present invention adopts a method in which potassium salt is used as both a precipitant and a precursor of a modified metal additive in the preparation process of pseudo-boehmite, and the metal additive is prompted to enter the pores of alumina through in-situ modification of potassium, thereby obtaining a catalyst with a concentrated pore structure (pores of 10-20 nm account for 60-80%), while removing the filter cake and removing K by multiple washing. + The steps are simplified, the production process is realized, and environmentally friendly production is achieved. The catalyst shows excellent desulfurization activity and selectivity.

[0183] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a hydrogenation catalyst, characterized in that: The steps include: Step 1, mixing a solution of an aluminum precursor and a solution of a portion of an alkaline precipitant, and controlling the mixing speed so that the pH value of the system is controlled at 7.0 to 9.0; Step 2, adding the remaining alkaline precipitant solution and the modified metal salt solution into the system of step 1, and controlling the pH value of the system to be between 7.0 and 9.0 by controlling the adding speed; Step 3, aging the system obtained in step 2 to obtain a modified alumina dry glue; Step 4, preparing the obtained modified alumina dry gel into a carrier, and then loading the active component to obtain a hydrogenation catalyst.

2. The method for preparing a hydrogenation catalyst according to claim 1, characterized in that: The alkaline precipitant is one or more of potassium carbonate, potassium hydroxide and potassium bicarbonate; after the system obtained in step 2 is aged, it also includes the steps of filtering and directly drying the filter cake to obtain modified alumina dry glue.

3. The method for preparing a hydrogenation catalyst according to claim 2, characterized in that: The amount of the alkaline precipitant added is such that the mass content of K in the obtained hydrogenation catalyst calculated as potassium oxide is 2% to 4%.

4. The method for preparing a hydrogenation catalyst according to claim 1, characterized in that: The aluminum precursor is a soluble aluminum salt, and the modified metal salt is at least one of a zirconium salt, a lanthanum salt, and a copper salt; the amount of the modified metal salt added is such that the mass content of the modified metal in the obtained hydrogenation catalyst is 0.1%-5% in terms of modified metal oxide.

5. The method for preparing a hydrogenation catalyst according to claim 1, characterized in that: The aluminum front drive The modified metal salt is at least one of zirconium nitrate, lanthanum nitrate, copper nitrate, zirconium acetate, lanthanum acetate and copper acetate.

6. The method for preparing a hydrogenation catalyst according to claim 1, characterized in that: In step 1, the mixing temperature of the aluminum precursor solution and the solution of part of the alkaline precipitant is 20-80° C., and the mixing time is 30-50 min.

7. The method for preparing a hydrogenation catalyst according to claim 1, characterized in that: The addition time of the remaining alkaline precipitant solution and the modified metal salt solution is 5-15 minutes, and the temperature of the system is controlled at 20-80°C.

8. The method for preparing a hydrogenation catalyst according to claim 2, characterized in that: The aging temperature is 60-100° C., and the aging time is 60-180 min. The filter cake is dried at 120-180° C., and the drying time is 60-120 min.

9. The method for preparing a hydrogenation catalyst according to claim 1, characterized in that: The steps of preparing the modified alumina dry glue into a carrier are as follows: the modified alumina dry glue is kneaded with a binder, a pore expander and an extrusion aid, and extruded into strips, and then dried and calcined to obtain the carrier; the binder is one or more of silica sol, nitric acid, acetic acid, and malic acid, the pore expander is one or more of citric acid, yeast, methyl cellulose, and hydroxypropyl methyl cellulose, and the extrusion aid is one or more of sesbania powder, starch and citric acid; the mass ratio of the binder to the modified alumina dry glue dry basis is 0.02-0.05:1, the mass ratio of the pore expander to the modified alumina dry glue dry basis is 0.01-0.1:1, and the mass ratio of the extrusion aid to the modified alumina dry glue dry basis is 0.01-0.05:

1.

10. The method for preparing a hydrogenation catalyst according to claim 1, characterized in that: The active component is at least one of the elements of group VIII and group VIB. In the hydrogenation catalyst, the mass content of the active component in terms of metal oxide is 9%-20%.

11. The method for preparing a hydrogenation catalyst according to claim 1, characterized in that: The active components are Mo and at least one of Co and Ni; in the hydrogenation catalyst, the content of Mo calculated as MoO3 is 8.0% to 16.0%, and the content of Co and / or Ni calculated as oxides is 1.0% to 4.0%.

12. Use of the hydrogenation catalyst obtained by the preparation method according to any one of claims 1 to 11 in distillate oil hydrodesulfurization.

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