Diesel oil refining adsorbent and preparation method thereof

Abstract

The invention discloses a diesel oil refining adsorbent and a preparation method thereof. The adsorbent comprises the following components in percentage by mass: 10%-15% of a modifier, 1.5%-4.5% of an activator, 2%-5% of halogenated salt, 60.5%-81.5% of a carrier and 5%-15% of a binder, the modifier is selected from at least one of iron oxide bonded with silicon oxide, copper oxide bonded with silicon oxide and zinc oxide bonded with silicon oxide; the activating agent is a cross-linked body of silicic acid and titanium sulfate; the halogenated salt is halogenated salt of alkali metal or alkaline earth metal. The adsorbent disclosed by the invention can selectively adsorb alkaline and non-alkaline nitrides in diesel oil, the removal rate of the nitrides is greater than 97%, and the adsorbent can be repeatedly used after being regenerated.

Description

Technical Field

[0001] The present invention relates to the field of petrochemical industry, and particularly to a diesel refining adsorbent and a preparation method thereof. Background Art

[0002] Diesel fuel, as an important fuel widely used in many fields such as transportation and industrial production, faces unprecedented challenges in its quality standards, especially in the control of the content of nitrogen compounds. In traditional diesel refining processes, from crude oil distillation to subsequent hydrorefining and other processes, although sulfur, nitrogen and other impurities in diesel can be reduced to a certain extent, for some nitrogen compounds with complex structures, it is difficult to achieve deep removal by conventional methods. Nitrogen compounds in diesel will produce nitrogen oxides (NOx) during the combustion process, and these substances are important factors leading to environmental problems such as haze, acid rain and photochemical smog. In addition, nitrogen compounds will compete with sulfides for the active sites of the catalyst during hydrodesulfurization, inhibit the efficiency of catalytic hydrodesulfurization, and even cause catalyst poisoning. Therefore, the development of efficient diesel denitrification technology is of great significance for reducing environmental pollution and improving diesel quality.

[0003] At present, hydrorefining is a commonly used denitrification method in industry, but this technology has disadvantages such as high investment cost, harsh reaction conditions, large hydrogen consumption and complex operation. In addition, the removal of nitrogen compounds usually needs to be carried out after the hydrogenation saturation of aromatic rings, which not only increases hydrogen consumption but also may lead to a decrease in the cetane number of diesel. As an emerging and highly potential alternative or supplementary solution, adsorption denitrification technology has emerged. Compared with hydrodenitrification, adsorption denitrification has mild operating conditions, usually can be carried out at normal temperature and pressure or slightly higher temperature and lower pressure, without large-scale high-pressure hydrogenation devices, greatly reducing equipment investment and operating costs; moreover, the adsorption process has strong selectivity, can accurately target and adsorb nitrogen compounds in diesel, avoid unnecessary effects on other beneficial components of diesel, and is conducive to maintaining the overall performance of diesel.

[0004] For example, Chinese invention patent with publication number CN109759010A discloses a molecular sieve adsorbent for deep removal of organic nitrogen compounds, its preparation method and application. The adsorbent is composed of Y-type molecular sieve modified by rare earth metals, and the loading amount of rare earth metals is 5-20 wt%; the types of rare earth metals are sulfates, nitrates of lanthanum and yttrium or their mixtures. The adsorption capacity of the adsorbent for nitrogen can reach 24 mg nitrogen / g adsorbent. The adsorbed adsorbent is calcined in a muffle furnace at 500 °C for 4 hours in an air atmosphere for regeneration, and can be used continuously after regeneration. After two regenerations, the adsorption capacity is still more than 97% of the initial adsorption capacity.

[0005] The Chinese invention patent with the publication number CN104232149A discloses a material for efficiently removing basic nitrogen compounds from oil products. An oxidized modified graphite is prepared by using oxidation and drying methods. Its adsorption capacity for quinoline mainly depends on its high oxygen content and the oxygen-containing functional groups generated during the oxidation process. Its adsorption capacity for quinoline and methyl-substituted quinoline in oil products is extremely high. In addition, the experimental results of the influence of different solvents on its adsorption capacity also prove that the high adsorption capacity of this adsorbent is not easily affected by other components in the oil product like traditional oxidized activated carbon adsorbents.

[0006] The Chinese invention patent with the publication number CN114471451A discloses a preparation method and application of an adsorbent for removing basic nitrogen compounds from lubricating base oil. The adsorbent is in an amorphous state and is prepared by equilibrated volume impregnation for 12 h by adding an active component solution with a certain concentration to the dried clay powder, and then drying and grinding it. After drying, it is mixed with the lubricating base oil, stirred for a certain time at 180 °C under nitrogen protection, and then filtered to obtain the raffinate with a lower basic nitrogen compound content. When the clay addition reaches a certain value, the basic nitrogen removal rate of the base oil reaches 93.37%.

[0007] Another Chinese invention patent with the publication number CN103184065A discloses a method for adsorptive removal of nitrogen compounds in diesel. Through the contact adsorption denitrification of an Al-MCM-41 molecular sieve adsorbent and diesel in a batch reaction device or a fixed-bed reaction device at 75 - 110 °C, it can be used for the adsorption refining of diesel and the pretreatment part of adsorption denitrification in the adsorption-hydrogenation combined refining of diesel, thereby improving the hydrogenation depth of the hydrogenation unit.

[0008] Another Chinese invention patent with the publication number CN113088326A discloses a process for diesel adsorption-catalytic oxidation tandem ultra-deep desulfurization and denitrification. Diesel is passed through an adsorption tower, and the adsorbent adsorbs and removes sulfur and nitrogen compounds in the diesel to obtain ultra-low sulfur diesel; the adsorbent used is two-dimensional boron nitride, BN-C. The adsorbent is transferred to an oxidation regeneration tower, and air or oxygen is blown in. The sulfur and nitrogen compounds adsorbed in the adsorbent are highly selectively oxidized into stronger polar oxidation products by catalytic oxidation; the oxidized adsorbent enters an elution tower to elute and separate the adsorbent and the oxidation products, and the regeneration of the adsorbent is carried out; the oxidation products enter a fractionation tower to fractionally recover different types of high-value oxidation products.

[0009] Another Chinese invention patent with the publication number CN108102693A discloses a method for removing basic nitrogen compounds in shale oil by cobalt-nickel bimetallic ion modified silica gel. On the basis of silica gel activation, by loading Co 2+ , Ni 2+, which greatly improves the adsorption and denitrification performance of activated silica gel. By using the multi-stage adsorption and denitrification method, not only can the adsorbent be fully utilized, but also the denitrification effect can be greatly improved. The experimental conditions for denitrification are mild and the denitrification rate is high.

[0010] For another example, the Chinese invention patent with the publication number CN1748020A discloses a method for removing nitrogen-containing impurities from a crude diesel feed stream. First, a C12 and higher hydrocarbon petroleum feed containing nitrogen and sulfur compounds is treated with a porous particle adsorbent comprising a silica framework having metal atoms with a Lewis acidity of at least 500 μmol / g. Subsequently, the resulting feed is treated with a catalytic hydrodesulfurization process to produce a hydrocarbon fuel with low sulfur and nitrogen contents.

[0011] For another example, the Chinese invention patent with the publication number CN104560124A discloses a method for deep denitrification of fuel oil for the automotive industry. The fuel oil first passes through an adsorption column for adsorption to remove some polar compounds. The adsorbent in the adsorption column is selected from activated alumina, acid clay, bleaching earth, activated carbon, zeolite, hydrated alumina, silica gel, ion exchange resin, or a combination thereof; then it passes through a refining column for deep denitrification, and the deep denitrification adsorbent used is a modified ZSM-5 molecular sieve.

[0012] However, the above technologies for removing nitrogen compounds from diesel by adsorption still have the following problems that need to be improved: The nitrogen compounds in diesel include basic and non-basic nitrogen compounds. Currently, the adsorbent mainly adsorbs the basic nitrogen compounds in diesel, and the adsorption amount of non-basic nitrogen compounds is low, which affects the nitrogen compound removal rate, and the regeneration of the adsorbent is relatively difficult; The sulfides and aromatics in diesel will have competitive adsorption with nitrogen compounds, reducing the adsorption capacity of the adsorbent for nitrogen compounds. Summary of the Invention

[0013] In order to solve the problems existing in the prior art, such as the low adsorption amount of nitrogen compounds in diesel by the adsorbent, low removal rate, insufficient selective adsorption ability, and large regeneration difficulty, the present invention provides a diesel refining adsorbent and a preparation method thereof. When the adsorbent adsorbs nitrogen compounds in diesel, it can effectively reduce the adsorption amount of sulfides and aromatics, increase the adsorption amount of nitrogen compounds, including basic and non-basic nitrogen compounds, improve the nitrogen compound removal rate, and can be repeatedly used through regeneration to achieve the effect of diesel refining.

[0014] In the first aspect, the present invention provides a diesel refining adsorbent, which is achieved by the following technical solutions.

[0015] A diesel refining adsorbent, comprising components in the following mass percentages: modifier 10 - 15%, activator 1.5 - 4.5%, halogenated salt 2 - 5%, carrier 60.5 - 81.5%, binder 5 - 15%; the modifier is selected from at least one of iron oxide bonded to silica, copper oxide bonded to silica, and zinc oxide bonded to silica; the activator is a cross-linked body of silicic acid and titanium sulfate; the halogenated salt is a halogenated salt of an alkali metal or an alkaline earth metal.

[0016] By adopting the above technical solution, when the refining adsorbent is saturated with the adsorption of nitrogen compounds in diesel, the adsorption amount of nitrogen compounds is greater than 250 mg / g, the adsorption amount of sulfide is less than 10 mg / g, and the adsorption amount of aromatic hydrocarbons is less than 10 mg / g; and it can selectively adsorb basic and non-basic nitrogen compounds, the nitrogen compound removal rate is greater than 97%, and it can be reused after regeneration.

[0017] Furthermore, the mass fraction of silica in the modifier is 30 - 50%.

[0018] Furthermore, the mass fraction of titanium sulfate in the activator is 70 - 80%.

[0019] Furthermore, the carrier is selected from at least one of silica gel, alumina, and amorphous silica-aluminum, and the pore volume of silica gel, alumina, and amorphous silica-aluminum is greater than 0.4 cm 3 / g.

[0020] In a second aspect, the present invention provides a preparation method of a diesel refining adsorbent, which is realized by adopting the following technical solution.

[0021] A preparation method of the above diesel refining adsorbent, comprising the following steps:

[0022] S1. Mix the carrier evenly with an aqueous solution containing lower alcohol, tetraethyl orthosilicate, and metal salt, heat up to 100 - 150 °C and react for 2 - 6 h, then adjust the pH to 8 - 10, continue to react for 4 - 10 h, filter and dry to obtain a modified carrier;

[0023] S2. Add water glass to an inorganic acid solution containing titanium sulfate, control the pH to 1.5 - 3, and react at room temperature for 2 - 6 h to obtain an activator containing a cross-linked body of silicic acid and titanium sulfate;

[0024] S3. Crush the modified carrier and the activator to a particle size D90 less than 10 μm, and react at room temperature for 1 - 3 h, then mix with the binder and granulate and shape, dry and calcine to obtain an activated carrier;

[0025] S4. Load the halogenated salt onto the activated carrier, and then obtain the diesel refining adsorbent after drying and calcining.

[0026] By adopting the above technical solution, first, the support is modified by the metal oxide of bonded silica to modulate the pore structure and surface properties of the support, generate a surface that is easy to combine with the activator, and prepare a cross-linked body containing silicic acid and titanium sulfate as the activator; then, during the mixing and crushing of the modified support and the activator, the cross-linked body of silicic acid and titanium sulfate is evenly distributed on the surface of the support to further adjust the surface adsorption properties; finally, the halogenated salt is loaded into the active support to form a multi-level surface structure. Through the synergistic effect, both basic and non-basic nitrogen compounds in diesel can be adsorbed simultaneously, improving the selective adsorption force for nitrogen compounds in diesel.

[0027] Further, in step S1, the lower alcohol is selected from at least one of methanol, ethanol, and propanol; the metal salt is selected from at least one of ferric nitrate, copper nitrate, zinc nitrate, ferric chloride, copper chloride, and zinc chloride; the mass fraction of the lower alcohol in the aqueous solution is 2-6%, the mass fraction of tetraethyl orthosilicate is 1-3%, and the mass fraction of the metal salt is 1.5-4%.

[0028] Further, in step S1, ammonia water is used to adjust the pH to 8-10.

[0029] Further, in step S2, the mass fraction of silicon oxide in the sodium silicate is 8-15%; the inorganic acid is at least one of hydrochloric acid and nitric acid, and the mass fraction of the inorganic acid is 2-5%; the molar ratio of the inorganic acid to silicon oxide in the sodium silicate is (1.2-2.5):1.

[0030] Further, in step S3, the binder is pseudo-boehmite; the calcination condition is calcination at 500-600°C for 2-6 h.

[0031] Further, in step S4, the halogenated salt is selected from at least one of sodium chloride, potassium chloride, magnesium chloride, calcium chloride, sodium bromide, potassium bromide, magnesium bromide, and calcium bromide; the loading method is impregnation; the calcination condition is calcination at 500-600°C for 2-6 h.

[0032] In the third aspect, the use of the diesel refining adsorbent provided by the present invention is realized by adopting the following technical solution.

[0033] An application of the above diesel refining adsorbent in removing nitrogen compounds from diesel. The diesel refining adsorbent can selectively adsorb both basic and non-basic nitrogen compounds simultaneously. When the adsorption of nitrogen compounds in diesel is saturated, the adsorption amount of nitrogen compounds is greater than 250 mg / g, the adsorption amount of sulfides is less than 10 mg / g, and the adsorption amount of aromatics is less than 10 mg / g.

[0034] This application has the following beneficial effects.

[0035] (1) The adsorbent of the present invention contains a multi-stage surface structure of a metal oxide bonded to silica, a cross-linked body of silicic acid and titanium sulfate, and a halogenated salt. Through a synergistic effect among them, active centers with selective adsorption for nitrogen compounds in diesel are formed, including basic and non-basic nitrogen compounds. The total nitrogen compound removal rate is greater than 97%; and the adsorbent has a smooth pore structure, providing sufficient space for the adsorption of nitrogen compounds.

[0036] (2) When the adsorbent of the present invention adsorbs nitrogen compounds in diesel, it can avoid the competitive adsorption of sulfides and aromatics on nitrogen compounds, can selectively preferentially adsorb nitrogen compounds, increase the adsorption amount of nitrogen compounds, reduce the adsorption amount of sulfides and aromatics, and can regenerate the adsorbent by solvent elution to restore the denitrification performance. Detailed implementation manners

[0037] The following further illustrates this patent application with reference to examples.

[0038] In the following examples, the materials used in the preparation process are not specially described and are all obtained through commercial channels without further treatment.

[0039] In the water glass used in the examples of the present invention, the mass concentration of silica is 12%. The pore volume of the silica gel used is 0.53 cm 3 / g, the pore volume of the alumina used is 0.74 cm 3 / g, and the pore volume of the amorphous silica-alumina is 0.62 cm 3 / g.

[0040] Example 1

[0041] A preparation method of a diesel refining adsorbent includes the following steps:

[0042] (1) A 2000 g aqueous solution containing 80 g of ethanol, 40 g of tetraethyl orthosilicate, and 55.2 g of iron nitrate is mixed evenly with 230.4 g of silica, heated to 100 °C and reacted for 6 h, then the pH is adjusted to 8 with ammonia water, and the reaction is continued for 4 h, and then filtered and dried to obtain a modified carrier.

[0043] (2) 3.2 g of titanium sulfate is dissolved in 50 g of hydrochloric acid with a mass concentration of 3%, and then 9.2 g of water glass is added, and stirred at room temperature for 3 h to obtain an activator containing a cross-linked body of silicic acid and titanium sulfate.

[0044] (3) The modified carrier in step (1) and the activator in step (2) are crushed in an emulsifier to a particle size D90 less than 10 μm, reacted at room temperature for 3 h, and then mixed and granulated with 18.8 g of pseudoboehmite, dried, and calcined at 500 °C for 6 h to obtain an active carrier.

[0045] (4) Dissolve 5.6 g of sodium chloride in 288 g of water, then impregnate and load it into the activated carrier in step (3), and then dry and calcine at 500 °C for 6 h to obtain the diesel refining adsorbent. The composition of the adsorbent was measured by X-ray fluorescence spectrometry, as shown in Table 1.

[0046] Example 2

[0047] A preparation method of a diesel refining adsorbent, comprising the following steps:

[0048] (1) Mix 2000 g of an aqueous solution containing 80 g of ethanol, 40 g of tetraethyl orthosilicate, and 55.2 g of iron nitrate uniformly with 115.2 g of silica, heat up to 150 °C and react for 2 h, then adjust the pH to 10 with ammonia water, continue to react for 10 h, and then filter and dry to obtain a modified carrier.

[0049] (2) Dissolve 6.4 g of titanium sulfate in 100 g of nitric acid with a mass concentration of 3%, and then add 18 g of water glass, and stir at room temperature for 1.5 h to obtain an activator containing a cross-linked body of silicic acid and titanium sulfate.

[0050] (3) Crush the modified carrier in step (1) and the activator in step (2) in an emulsifier to a particle size D90 less than 10 μm, react at room temperature for 1 h, and then mix and granulate with 29.6 g of pseudoboehmite, dry and calcine at 600 °C for 2 h to obtain an activated carrier.

[0051] (4) Dissolve 9.6 g of magnesium bromide in 192 g of water, then impregnate and load it into the activated carrier in step (3), and then dry and calcine at 600 °C for 2 h to obtain the diesel refining adsorbent. The composition of the adsorbent was measured by X-ray fluorescence spectrometry, as shown in Table 1.

[0052] Example 3

[0053] A preparation method of a diesel refining adsorbent, comprising the following steps:

[0054] (1) Mix 2000 g of an aqueous solution containing 80 g of ethanol, 40 g of tetraethyl orthosilicate, and 81.2 g of copper nitrate uniformly with 180 g of alumina, heat up to 120 °C and react for 4 h, then adjust the pH to 9 with ammonia water, continue to react for 6 h, and then filter and dry to obtain a modified carrier.

[0055] (2) Dissolve 5.4 g of titanium sulfate in 80 g of hydrochloric acid with a mass concentration of 3%, and then add 15 g of water glass, and stir at room temperature for 2 h to obtain an activator containing a cross-linked body of silicic acid and titanium sulfate.

[0056] (3) Crush the modified support in step (1) and the activator in step (2) in an emulsifier to a particle size D90 less than 10 μm, react at room temperature for 2 h, then mix and granulate with 16.8 g of pseudoboehmite, dry, and calcine at 550 °C for 4 h to obtain the activated support.

[0057] (4) Dissolve 7.2 g of calcium chloride in 240 g of water, then impregnate and load it onto the activated support in step (3), and then dry and calcine at 550 °C for 4 h to obtain the diesel refining adsorbent. The composition of the adsorbent is measured by X-ray fluorescence spectrometry, as shown in Table 1.

[0058] Example 4

[0059] A preparation method of a diesel refining adsorbent, comprising the following steps:

[0060] (1) Mix 2000 g of an aqueous solution containing 80 g of ethanol, 40 g of tetraethyl orthosilicate, and 79.7 g of zinc nitrate evenly with 180 g of alumina, heat up to 120 °C and react for 4 h, then adjust the pH to 9 with ammonia water and continue to react for 6 h, and then filter and dry to obtain the modified support.

[0061] (2) Dissolve 5.4 g of titanium sulfate in 80 g of hydrochloric acid with a mass concentration of 3%, and then add 15 g of water glass and stir at room temperature for 2 h to obtain an activator containing a cross-linked body of silicic acid and titanium sulfate.

[0062] (3) Crush the modified support in step (1) and the activator in step (2) in an emulsifier to a particle size D90 less than 10 μm, react at room temperature for 2 h, then mix and granulate with 16.8 g of pseudoboehmite, dry, and calcine at 550 °C for 4 h to obtain the activated support.

[0063] (4) Dissolve 7.2 g of potassium bromide in 240 g of water, then impregnate and load it onto the activated support in step (3), and then dry and calcine at 550 °C for 4 h to obtain the diesel refining adsorbent. The composition of the adsorbent is measured by X-ray fluorescence spectrometry, as shown in Table 1.

[0064] Example 5

[0065] A preparation method of a diesel refining adsorbent, comprising the following steps:

[0066] (1) Mix 2000 g of an aqueous solution containing 80 g of ethanol, 40 g of tetraethyl orthosilicate, and 52.3 g of iron nitrate evenly with 180 g of amorphous silica-alumina, heat up to 120 °C and react for 4 h, then adjust the pH to 9 with ammonia water and continue to react for 6 h, and then filter and dry to obtain the modified support.

[0067] (2) Dissolve 5.4 g of titanium sulfate in 80 g of hydrochloric acid with a mass concentration of 3%, then add 15 g of sodium silicate, and stir at room temperature for 2 h to obtain an activator containing silicic acid and a titanium sulfate crosslinking body.

[0068] (3) Crush the modified carrier in step (1) and the activator in step (2) in an emulsifier to a particle size D90 less than 10 μm, react at room temperature for 2 h, then mix and granulate with 16.8 g of pseudoboehmite, dry, and calcine at 550 °C for 4 h to obtain an activated carrier.

[0069] (4) Dissolve 7.2 g of potassium chloride in 240 g of water, then impregnate and load it into the activated carrier in step (3), and then dry and calcine at 550 °C for 4 h to obtain the diesel refining adsorbent. The composition of the adsorbent is measured by X-ray fluorescence spectrometry, as shown in Table 1.

[0070] Comparative Example 1

[0071] A preparation method of a diesel refining adsorbent includes the following steps:

[0072] (1) Mix 2000 g of an aqueous solution containing 120 g of ethanol and 99.8 g of tetraethyl orthosilicate evenly with 180 g of amorphous silica-alumina, raise the temperature to 120 °C and react for 4 h, then adjust the pH to 9 with ammonia water and continue to react for 6 h, and then filter and dry to obtain a modified carrier.

[0073] Steps (2), (3), and (4) are the same as those in Example 5. The composition of the adsorbent is measured by X-ray fluorescence spectrometry, as shown in Table 1.

[0074] Comparative Example 2

[0075] A preparation method of a diesel refining adsorbent includes the following steps:

[0076] (1) Mix 2000 g of an aqueous solution containing 120 g of ethanol and 99.8 g of tetraethyl orthosilicate evenly with 180 g of amorphous silica-alumina, raise the temperature to 120 °C and react for 4 h, then adjust the pH to 9 with ammonia water and continue to react for 6 h, and then filter and dry to obtain a modified carrier.

[0077] (2) Add 60 g of sodium silicate to 320 g of hydrochloric acid with a mass concentration of 3%, and stir at room temperature for 2 h to obtain an activator containing silicic acid.

[0078] Steps (3) and (4) are the same as those in Example 5. The composition of the adsorbent is measured by X-ray fluorescence spectrometry, as shown in Table 1.

[0079] Comparative Example 3

[0080] A preparation method of a diesel refining adsorbent includes the following steps:

[0081] (1) Mix 2000 g of an aqueous solution containing 120 g of ethanol and 99.8 g of tetraethyl orthosilicate uniformly with 180 g of amorphous silica-alumina, heat it to 120 °C and react for 4 h, then adjust the pH to 9 with ammonia water and continue to react for 6 h, and then filter and dry to obtain a modified support.

[0082] (2) Add 60 g of water glass to 320 g of hydrochloric acid with a mass concentration of 3%, stir at room temperature for 2 h to obtain an activator containing silicic acid.

[0083] (3) The same as Example 5.

[0084] (4) The activated support is dried and calcined at 550 °C for 4 h to obtain the adsorbent of Comparative Example 3. The composition of the adsorbent is measured by X-ray fluorescence spectrometry, as shown in Table 1.

[0085] Table 1 Analysis of Adsorbent Composition

[0086] Adsorbent Modifier, wt% Activator, wt% Halide salt, wt% Support, wt% Binder, wt% Example 1 10.1 1.6 2.2 79.7 6.4 Example 2 14.8 4.4 4.9 61.1 14.8 Example 3 12.1 3.2 3.1 74.8 6.8 Example 4 12.0 3.1 3.2 74.8 6.9 Example 5 12.1 3.1 3.1 74.7 7.0 Comparative Example 1 12.1 3.1 3.1 74.7 7.0 Comparative Example 2 12.1 3.1 3.1 74.7 7.0 Comparative Example 3 12.5 3.2 0 77.1 7.2

[0087] Note: Ferric nitrate is not added during the synthesis process of Comparative Example 1, ferric nitrate and titanium sulfate are not added during the synthesis process of Comparative Example 2, and ferric nitrate, titanium sulfate and potassium chloride are not added during the synthesis process of Comparative Example 3.

[0088] Evaluation methods for the adsorbents in Examples 1-5 and Comparative Examples 1-3:

[0089] Adsorption capacity evaluation: Use a fixed-bed adsorption column, load 60 g of the adsorbent into the adsorption column, then introduce a certain amount of methylcyclohexane, set the temperature to 50 °C and the pressure to 0.5 MPa, remove the bubbles in the adsorption column, and then introduce diesel into the adsorption column at a rate of 0.1 ml / min. Regularly detect the contents of nitrogen compounds, sulfides and aromatics at the outlet. When the content of nitrogen compounds at the outlet is the same as that of the diesel raw material, stop feeding, and calculate the adsorption capacity of the adsorbent for nitrogen compounds, sulfides and aromatics in diesel at this time. The evaluation results are shown in Table 2.

[0090] Removal rate evaluation: Use a fixed-bed adsorption column, load 60 g of the adsorbent into the adsorption column, set the temperature to 50 °C and the pressure to 0.5 MPa, introduce diesel into the adsorption column at a rate of 0.1 ml / min, and the cumulative feed amount is 9 L. Detect the concentration of nitrogen compounds in all the effluent as C1 and the concentration of nitrogen compounds at the inlet as C0. According to the formula: removal rate = (1 - C1÷C0) × 100%, which is recorded as the nitrogen compound removal rate of the fresh agent. Then switch to methanol to elute the adsorbent, stop eluting when no nitrogen compounds are detected at the outlet, switch to nitrogen purge at 200 °C, and stop purging when no methanol is detected at the outlet to complete the regeneration of the adsorbent. Then repeat the above removal rate evaluation process to obtain the nitrogen compound removal rate of the regenerated agent. The evaluation results are shown in Table 2.

[0091] The diesel raw material used for adsorbent evaluation is the second normal distillate diesel from a refinery, with a nitride content of 22.9 ppm (including 6.8 ppm of basic nitrides and 16.1 ppm of non-basic nitrides), a sulfide content of 1674.8 ppm, and an aromatic hydrocarbon content of 17.7 wt%.

[0092] Table 2 Adsorbent Evaluation Results

[0093]

[0094] As can be seen from the data in Table 2, when the adsorbent of the present invention adsorbs nitrides in diesel, it has a high nitride adsorption capacity, extremely low sulfide and aromatic hydrocarbon adsorption capacities; the nitride removal rate is high, indicating that it has a significant selective adsorption and removal effect on both basic and non-basic nitrides. The nitride content (including basic nitrides and non-basic nitrides) in the refined diesel is less than 1 ppm, and it is easy to regenerate and restore the denitrification performance by solvent elution, thus realizing diesel refining.

[0095] The embodiments of this specific implementation manner are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A diesel refining adsorbent, characterized in that: The components include the following mass percentages: modifier 10 - 15%, activator 1.5 - 4.5%, halogenated salt 2 - 5%, carrier 60.5 - 81.5%, binder 5 - 15%; the modifier is selected from at least one of iron oxide bonded with silica, copper oxide bonded with silica, and zinc oxide bonded with silica; the activator is a cross-linked body of silicic acid and titanium sulfate; the halogenated salt is a halogenated salt of an alkali metal or an alkaline earth metal.

2. The diesel refining adsorbent according to claim 1, wherein: The mass fraction of silica in the modifier is 30 - 50%.

3. The diesel refining adsorbent according to claim 1, wherein: The mass fraction of titanium sulfate in the activator is 70 - 80%.

4. The diesel refining adsorbent according to claim 1, characterized in that: The carrier is selected from at least one of silica gel, alumina, and amorphous silica-alumina, and the pore volume of silica gel, alumina, and amorphous silica-alumina is greater than 0.4 cm 3 / g.

5. A method for preparing the diesel refining adsorbent according to any one of claims 1-4, characterized in that: It includes the following steps: S1. Mix the carrier evenly with an aqueous solution containing a lower alcohol, tetraethyl orthosilicate, and a metal salt, heat up to 100 - 150 °C and react for 2 - 6 h, then adjust the pH to 8 - 10 and continue to react for 4 - 10 h, filter and dry to obtain a modified carrier. S2. Add sodium silicate to an inorganic acid solution containing titanium sulfate, control the pH to 1.5 - 3, and react at room temperature for 2 - 6 h to obtain an activator containing a cross-linked body of silicic acid and titanium sulfate. S3. Crush the modified carrier and the activator to a particle size D90 less than 10 μm, react at room temperature for 1 - 3 h, then mix and granulate with the binder, dry and calcine to obtain an activated carrier. S4. Load the halogenated salt onto the activated carrier, and then obtain a diesel refining adsorbent after drying and calcining.

6. The preparation method of a diesel refining adsorbent according to claim 5, characterized in that: In step S1, the lower alcohol is selected from at least one of methanol, ethanol, and propanol; the metal salt is selected from at least one of ferric nitrate, copper nitrate, zinc nitrate, ferric chloride, copper chloride, and zinc chloride; the mass fraction of the lower alcohol in the aqueous solution is 2 - 6%, the mass fraction of tetraethyl orthosilicate is 1 - 3%, and the mass fraction of the metal salt is 1.5 - 4%.

7. The preparation method of a diesel refining adsorbent according to claim 5, characterized in that: In step S2, the mass fraction of silica in the sodium silicate is 8 - 15%; the inorganic acid is at least one of hydrochloric acid and nitric acid, and the mass fraction of the inorganic acid is 2 - 5%; the molar ratio of the inorganic acid to silica in the sodium silicate is (1.2 - 2.5):

1.

8. The preparation method of a diesel refining adsorbent according to claim 5, characterized in that: In step S3, the binder is pseudo-boehmite; the calcination condition is calcination at 500 - 600 °C for 2 - 6 h.

9. The preparation method of a diesel refining adsorbent according to claim 5, characterized in that: In step S4, the halogenated salt is selected from at least one of sodium chloride, potassium chloride, magnesium chloride, calcium chloride, sodium bromide, potassium bromide, magnesium bromide, and calcium bromide; the loading method is impregnation; the calcination condition is calcination at 500 - 600 °C for 2 - 6 h.

10. Use of the diesel refining adsorbent according to claim 1 in removing nitrogen compounds from diesel, characterized in that, The diesel refining adsorbent can selectively adsorb both basic and non-basic nitrogen compounds simultaneously. When the nitrogen compounds in diesel are adsorbed to saturation, the adsorption amount of nitrogen compounds is greater than 250 mg / g, the adsorption amount of sulfides is less than 10 mg / g, and the adsorption amount of aromatics is less than 10 mg / g.

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