A rare earth metal oxide desulfurizer and a method for preparing the same

Abstract

The application relates to the technical field of desulfurizers, and particularly discloses a rare earth metal oxide desulfurizer and a preparation method thereof. The preparation method comprises the following steps: S1: dissolving cerium salt, lanthanum salt and glucose in water to obtain solution A; S2: impregnating pre-calcined gamma-Al2O3 with the solution A, drying, calcining at 300-400 DEG C for 2-4 hours, cooling, and obtaining a loaded substance A; S3: dissolving copper salt, nickel salt and citric acid in water to obtain solution B; S4: impregnating the loaded substance A with the solution B, drying, calcining at 450-550 DEG C for 2-4 hours, cooling, and obtaining a loaded substance B; and S5: placing the loaded substance B in a reducing atmosphere, heating to 300-400 DEG C, keeping for 2-3 hours, cooling, and obtaining the rare earth metal oxide desulfurizer. The rare earth metal oxide desulfurizer prepared by the application has relatively high desulfurization efficiency and octane value RON retention rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of desulfurizer, more particularly, it relates to a rare earth metal oxide desulfurizer and a preparation method thereof. BACKGROUND

[0002] With the increasingly stringent global environmental regulations, the sulfur content limit in oil products has been generally reduced to below 10 ppm, and the development of efficient deep desulfurization technology has become an urgent demand of the oil refining industry. Copper-nickel desulfurizer is widely used in sulfur purification process of gasoline, diesel desulfurization and coal-to-oil, coal-to-gas process due to its good sulfur adsorption and reaction activity. The desulfurizer is generally produced by impregnation process, that is, the carrier such as alumina or molecular sieve is impregnated in copper and nickel salt solution to adsorb and load active components, then a binder and a pore-forming agent are added, and finally the desulfurizer with CuO-NiO active phase is formed by calcination. However, the traditional copper-nickel desulfurizer usually adopts multi-metal salt co-impregnation process, and the desulfurizer prepared by the process has small sulfur capacity and poor selectivity to refractory sulfides (such as thiophenes).

[0003] The patent application file with publication number CN105126597A discloses a preparation method of refinery waste gas desulfurizer, which comprises the following steps: (1) placing activated carbon in an alcohol solution containing nitrogen compounds, stirring, filtering, collecting the filter cake, vacuum drying, and calcining under inert atmosphere to obtain modified activated carbon; (2) dissolving copper salt, nickel salt and cerium salt in deionized water to form a Cu-Ni-Ce composite solution; placing the modified activated carbon in the Cu-Ni-Ce composite solution, ultrasonic impregnation for 2-8 hours, filtering, collecting the filter cake, drying, and calcining under inert atmosphere; (3) adding cobalt phthalocyanine and a cosolvent to an aqueous ammonia solution to form a cobalt-containing impregnation solution; placing the calcined product of step (2) in the cobalt-containing impregnation solution, ultrasonic impregnation for 12-48 hours, filtering, collecting the filter cake, and vacuum drying to obtain the refinery waste gas desulfurizer.

[0004] In the technical solution, copper salt, nickel salt and cerium salt are used for co-impregnation. Since Cu 2+ , Ni 2+ and Ce 3+ have significant differences in charge, ionic radius and hydrolysis tendency, competitive adsorption will inevitably occur when they are combined with the functional groups on the surface of the carrier. Specifically, Cu 2+ and Ni 2+ ions preferentially occupy the microporous structure and high active sites of the carrier due to their smaller hydrated ionic radius and stronger coordination ability, while Ce 3+ ions are sparsely distributed on the outer surface or low active area due to their larger hydrated radius and weaker coordination ability, which makes it difficult for rare earth elements to form effective synergistic effect with transition metals, thereby restricting the adsorption capacity and catalytic conversion efficiency of the desulfurizer to complex sulfides (such as thiophenes). SUMMARY

[0005] In order to improve the adsorption capacity and catalytic conversion efficiency of the desulfurizer to complex sulfides (such as thiophenes), the application provides a rare earth metal oxide desulfurizer and a preparation method thereof.

[0006] In a first aspect, the application provides a preparation method of a rare earth metal oxide desulfurizer, which adopts the following technical scheme:

[0007] A preparation method of a rare earth metal oxide desulfurizer, comprising the following steps:

[0008] S1: Dissolve cerium salt, lanthanum salt and glucose in water to obtain solution A;

[0009] S2: Impregnate, dry and then calcine the pre-calcined γ-Al2O3 and solution A at a ratio of 1g: (0.5-0.6) mL at 300-400℃ for 2-4h, and then cool to obtain the loaded material A;

[0010] S3: Dissolve copper salt, nickel salt and citric acid in water to obtain solution B;

[0011] S4: Impregnate, dry and then calcine the loaded material A and solution B at a ratio of 1g: (0.4-0.5) mL at 450-550℃ for 2-4h, and then cool to obtain the loaded material B;

[0012] S5: Place the loaded material B in a reducing atmosphere, heat to 300-400℃, keep warm for 2-3h, and then cool to obtain the rare earth metal oxide desulfurizer.

[0013] In the technical scheme, first, the glucose in solution A forms stable complex with Ce 3+ and La 3+ through the multi-hydroxyl structure, and inhibits the aggregation of metal ions by using the steric hindrance effect; the solution is effectively filled into the carrier pores by equal-volume impregnation, and the rare earth complex realizes double adsorption through physical filling and chemical coordination of the surface functional groups, and reaches controllable loading after dynamic equilibrium; during the low-temperature calcination (300-400℃), the amorphous carbon template is generated by pyrolysis of the glucose, which wraps the rare earth particles to prevent sintering, and at the same time, the multi-level pore structure is formed after the decomposition of the carbon, which significantly improves the specific surface area of the carrier; second, the loaded material A is impregnated in solution B containing Cu 2+ , Ni 2 + , at this time, the citric acid in solution B reacts with Cu 2+ , Ni 2+Forming a weak complex, which is initially adsorbed on the surface and pores of the support A by physical adsorption and electrostatic action. In the secondary roasting (450~550℃), the citric acid ligand is decomposed, promoting the strong interaction of metal oxides (CuO, NiO) and the carrier and rare earth species, and finally building a support B with high dispersion, sintering resistance and hierarchical pore structure, and then placed in a reducing atmosphere, and through controllable reduction (300~400℃), part of the metal oxides are converted into active phase, while part of the oxidation state species are reserved to maintain the structural stability, forming a desulfurization catalyst system with synergistic oxygen vacancies and metal active sites.

[0014] Preferably, in the solution A, the total molar concentration of cerium salt and lanthanum salt is 0.4~0.8mol / L.

[0015] Preferably, in the solution A, the molar concentration of glucose is (1~1.5) times of the total molar number of cerium salt and lanthanum salt.

[0016] Preferably, in the solution B, the total molar concentration of copper salt and nickel salt is 1~2mol / L.

[0017] Preferably, in the solution B, the molar concentration of citric acid is (0.1~0.2) times of the total molar number of copper salt and nickel salt.

[0018] Preferably, the total molar concentration of cerium salt and lanthanum salt in the solution A is less than the total molar concentration of copper salt and nickel salt in the solution B.

[0019] In the technical solution, the lower molar concentration of cerium salt and lanthanum salt, on the one hand, avoids the existence of cerium and lanthanum oxide in the form of independent agglomerates, and on the other hand, provides sufficient and anchorable interface for a large number of Cu and Ni active phases which migrate later.

[0020] Preferably, in the step S2, the preparation method of the pre-roasted γ-Al2O3 includes the following steps:

[0021] Put γ-Al2O3 in a sintering furnace, heat to 450~550℃, roast for 3~5h, cool, sieve, and get pre-roasted γ-Al2O3.

[0022] In the technical solution, through pre-roasting treatment, the water and residual organic impurities on the surface of γ-Al2O3 are effectively removed, the pore is dredged, the pore structure is optimized, and the crystal form is stabilized, which lays a foundation for subsequent uniform metal loading and stable desulfurizer performance.

[0023] Preferably, the immersion in the step S2 and the step S4 is ultrasonic assisted immersion or reduced pressure immersion.

[0024] Preferably, in the step S5, the support B is pretreated by the following steps before use:

[0025] After impregnating the load B with the ammonium molybdate solution in a ratio of 1 g: (0.5-0.6) mL, drying, and then calcining at 300-400°C for 2-2.5 h, and cooling.

[0026] Preferably, the molar concentration of the ammonium molybdate is 0.1-0.3 mol / L.

[0027] In the technical solution, the ammonium molybdate exists in the form of highly dispersed MoO x The ammonium molybdate, as a strong Lewis acid site, has extremely high adsorption affinity and polarization capacity for sulfur molecules containing lone pair electrons such as thiophene and mercaptan, and cooperates with the oxygen vacancies in the shell of the rare earth oxide to improve the adsorption capacity and low-temperature catalytic conversion efficiency of the desulfurizer for the most difficult-to-degrade thiophene sulfur molecules.

[0028] Preferably, the reducing atmosphere is a mixed atmosphere of H2 and N2, and the volume ratio of H2 to N2 in the mixed atmosphere is (10-15):(85-90).

[0029] Preferably, the step S1 further includes a step of adding a zirconium salt after the lanthanum salt.

[0030] Preferably, the amount of the zirconium salt is (0.1-0.2) times the total moles of the lanthanum salt and the cerium salt.

[0031] In the technical solution, the Zr 4+ The incorporation of CeO2lattice greatly increases the oxygen vacancy concentration, improves the oxygen storage capacity and electron mobility, significantly enhances the thermal stability of the CeO2phase, effectively inhibits the sintering and deactivation of the active components during high-temperature reaction or regeneration, and thus greatly prolongs the service life of the desulfurizer.

[0032] In a second aspect, the application provides a rare earth metal oxide desulfurizer prepared by the above preparation method.

[0033] In summary, the application has the following beneficial effects:

[0034] 1. In the preparation of the desulfurizer, the application adopts a step-by-step loading strategy of rare earth first and then active metal, which avoids the problem of competitive adsorption caused by the difference in ion properties, ensures the uniform distribution and high dispersity of each component on the carrier, and lays a foundation for constructing efficient active centers.

[0035] 2. In the application, the complexation of glucose and its controlled "carbon template" effect in an air atmosphere successfully construct a hierarchical pore structure rich in mesopores in the low-temperature calcination stage, significantly increasing the specific surface area and mass transfer efficiency of the carrier; at the same time, the carbon layer effectively isolates the rare earth oxide particles before high-temperature decomposition, inhibits the grain growth and sintering of the particles, and provides an excellent substrate for the subsequent loading of active components. Attached Figure Description

[0036] Figure 1 The XRD patterns of the rare earth metal oxide desulfurizers in Examples 1, 2, 4 and Comparative Example 2 are shown below.

[0037] Figure 2 XPS spectra of rare earth metal oxide desulfurizers in Examples 1, 2, 4 and Comparative Example 2. Detailed Implementation

[0038] The present application will be further described in detail below with reference to the embodiments.

[0039] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this application are all commercially available.

[0040] Example 1

[0041] The preparation method of the rare earth metal oxide desulfurizer in this embodiment includes the following steps:

[0042] S1: Dissolve 0.04 mol of cerium nitrate hexahydrate, 0.02 mol of lanthanum nitrate hexahydrate, and 0.07 mol of glucose in 100 mL of deionized water to obtain solution A;

[0043] S2: Pre-calcined γ-Al2O3 and solution A were mixed at a ratio of 1g:0.55mL, allowed to stand for 2 hours, and then transferred to a rotary evaporator (60rpm, 40℃). The mixture was impregnated under reduced pressure for 2 hours, dried at 110℃ to constant weight, transferred to a sintering furnace, heated to 350℃ at 3℃, calcined for 3 hours, and cooled to room temperature with the furnace to obtain the loaded material A.

[0044] S3: Dissolve 0.12 mol of copper nitrate hexahydrate, 0.04 mol of nickel nitrate hexahydrate, and 0.024 mol of citric acid in 100 mL of deionized water to obtain solution B;

[0045] S4: Mix loading material A and solution B at a ratio of 1g:0.45mL, let stand for 4h, place in a water bath, heat to 60℃, impregnate with ultrasonic assistance at 300W power and 40kHz frequency for 2h, dry at 110℃ to constant weight, transfer to a sintering furnace, heat to 500℃ at 3℃, calcine for 3h, and cool to room temperature with the furnace to obtain loading material B;

[0046] S5: Under a mixed atmosphere of H2 and N2, the loaded material B is placed in a fixed-bed reactor, heated to 350°C at 2°C, kept at that temperature for 2 hours, and then naturally cooled to room temperature. After that, it is purged with N2 for 30 minutes to obtain a rare earth metal oxide desulfurizing agent.

[0047] The volume ratio of H2 to N2 is 10:90.

[0048] A method for preparing pre-calcined γ-Al2O3 comprises the following steps:

[0049] The γ-Al2O3 is placed in a sintering furnace, heated to 500℃ at a rate of 5℃ / min, calcined for 4h, cooled to room temperature with the furnace, and then sieved through a 20 mesh standard sieve to obtain undersize, and then sieved through a 40 mesh standard sieve to obtain oversize, thereby obtaining the pre-calcined γ-Al2O3.

[0050] Example 2

[0051] A method for preparing the rare earth metal oxide desulfurizer of the present embodiment comprises the following steps:

[0052] S1: 0.03 mol of cerium nitrate hexahydrate, 0.01 mol of lanthanum nitrate hexahydrate, and 0.06 mol of glucose are dissolved in 100 mL of deionized water to obtain solution A;

[0053] S2: The pre-calcined γ-Al2O3 is mixed with solution A at a ratio of 1g:0.6 mL, and then allowed to stand for 3h, and then transferred into a rotary evaporator (60rpm, 50℃) for vacuum impregnation for 2h, and then dried to constant weight at 110℃, and then transferred into a sintering furnace and heated to 400℃ at a rate of 3℃, and then calcined for 2h, and then cooled to room temperature with the furnace, thereby obtaining the support A;

[0054] S3: 0.15 mol of copper nitrate hexahydrate, 0.05 mol of nickel nitrate hexahydrate, and 0.04 mol of citric acid are dissolved in 100 mL of deionized water to obtain solution B;

[0055] S4: The support A is mixed with solution B at a ratio of 1g:0.5 mL, and then allowed to stand for 5h, and then placed in a water bath and heated to 70℃, and then subjected to ultrasonic-assisted impregnation at a power of 300W and a frequency of 40 kHz for 3h, and then dried to constant weight at 110℃, and then transferred into a sintering furnace and heated to 450℃ at a rate of 3℃, and then calcined for 4h, and then cooled to room temperature with the furnace, thereby obtaining the support B;

[0056] S5: The support B is placed in a fixed bed reactor under a mixed atmosphere of H2 and N2, and then heated to 400℃ at a rate of 2℃, and then maintained at 400℃ for 2.5h, and then naturally cooled to room temperature, and then purged with N2 for 30min, thereby obtaining the rare earth metal oxide desulfurizer.

[0057] Herein, the volume ratio of H2 to N2 is 15:85.

[0058] A method for preparing pre-calcined γ-Al2O3 comprises the following steps:

[0059] The γ-Al2O3 is placed in a sintering furnace, heated to 550℃ at a rate of 5℃ / min, calcined for 3h, cooled to room temperature with the furnace, and then sieved through a 20 mesh standard sieve to obtain undersize, and then sieved through a 40 mesh standard sieve to obtain oversize, thereby obtaining the pre-calcined γ-Al2O3.

[0060] Example 3

[0061] The preparation method of the rare earth metal oxide desulfurizer of the present embodiment comprises the following steps:

[0062] S1: dissolve 0.05 mol of cerium nitrate hexahydrate, 0.03 mol of lanthanum nitrate hexahydrate and 0.08 mol of glucose in 100 mL of deionized water to obtain solution A;

[0063] S2: mix the pre-calcined γ-Al2O3 with solution A at a ratio of 1 g:0.5 mL, then stand for 4 h, and then transfer into a rotary evaporator (60 rpm, 50℃) for vacuum impregnation for 3 h, dry at 110℃ until constant weight, transfer into a sintering furnace, heat up to 300℃ at a rate of 3℃, calcine for 4 h, and then cool down to room temperature with the furnace, to obtain the support A;

[0064] S3: dissolve 0.07 mol of copper nitrate hexahydrate, 0.03 mol of nickel nitrate hexahydrate and 0.01 mol of citric acid in 100 mL of deionized water to obtain solution B;

[0065] S4: mix the support A with solution B at a ratio of 1 g:0.4 mL, then stand for 5 h, and then place in a water bath, heat up to 70℃, ultrasonic-assisted impregnation for 3 h at a power of 300 W and a frequency of 40 kHz, dry at 110℃ until constant weight, transfer into a sintering furnace, heat up to 550℃ at a rate of 3℃, calcine for 2 h, and then cool down to room temperature with the furnace, to obtain the support B;

[0066] S5: place the support B in a fixed bed reactor under a mixed atmosphere of H2 and N2, heat up to 300℃ at a rate of 2℃, keep for 3 h, naturally cool down to room temperature, and then purge with N2 for 30 min, to obtain the rare earth metal oxide desulfurizer.

[0067] The volume ratio of H2 and N2 is 15:85.

[0068] The preparation method of the pre-calcined γ-Al2O3 comprises the following steps:

[0069] Place the γ-Al2O3 in a sintering furnace, heat up to 450℃ at a rate of 5℃ / min, calcine for 5 h, cool down to room temperature with the furnace, take the undersize through a 20 mesh standard sieve, and then take the oversize through a 40 mesh standard sieve, to obtain the pre-calcined γ-Al2O3.

[0070] Example 4

[0071] The preparation method of the rare earth metal oxide desulfurizer of the present embodiment comprises the following steps:

[0072] S1: dissolve 0.035 mol of cerium nitrate hexahydrate, 0.015 mol of lanthanum nitrate hexahydrate and 0.06 mol of glucose in 100 mL of deionized water to obtain solution A;

[0073] S2: After mixing the pre-calcined γ-Al2O3 and solution A at a ratio of 1 g:0.6 mL, standing for 3 h, then transferring into a rotary evaporator (60 rpm, 50℃), impregnating under reduced pressure for 2 h, drying at 110℃ to constant weight, transferring into a sintering furnace, heating at a rate of 3℃ to 400℃, calcining for 3 h, cooling to room temperature with the furnace, to obtain the support A;

[0074] S3: Dissolving 0.12 mol of copper nitrate hexahydrate, 0.04 mol of nickel nitrate hexahydrate and 0.03 mol of citric acid in 100 mL of deionized water to obtain solution B;

[0075] S4: After mixing the support A and solution B at a ratio of 1 g:0.5 mL, standing for 5 h, placing in a water bath, heating to 70℃, ultrasonic-assisted impregnating for 2.5 h at a power of 300 W and a frequency of 40 kHz, drying at 110℃ to constant weight, transferring into a sintering furnace, heating at a rate of 3℃ to 500℃, calcining for 3 h, cooling to room temperature with the furnace, to obtain the support B;

[0076] S5: Placing the support B in a fixed bed reactor under a mixed atmosphere of H2 and N2, heating at a rate of 2℃ to 400℃, maintaining for 2.5 h, naturally cooling to room temperature, purging with N2 for 30 min, to obtain the rare earth metal oxide desulfurizer.

[0077] Among them, the volume ratio of H2 and N2 is 15:85.

[0078] The preparation method of the pre-calcined γ-Al2O3 comprises the following steps:

[0079] Placing the γ-Al2O3 in a sintering furnace, heating at a rate of 5℃ / min to 550℃, calcining for 3 h, cooling to room temperature with the furnace, taking the undersize through a 20 mesh standard sieve, taking the oversize through a 40 mesh standard sieve, to obtain the pre-calcined γ-Al2O3.

[0080] Example 5

[0081] The difference between this example and example 4 is:

[0082] In step S5, the support B is a pretreated support B, and the preparation method of the pretreated support B comprises the following steps:

[0083] After mixing the support B and an ammonium molybdate solution with a molar concentration of 0.1 mol / L at a ratio of 1 g:0.6 mL, standing for 2 h, then transferring into a rotary evaporator (60 rpm, 50℃), impregnating under reduced pressure for 2 h, drying at 110℃ to constant weight, transferring into a sintering furnace, heating at a rate of 3℃ to 300℃, calcining for 2 h, cooling to room temperature, to obtain the pretreated support B.

[0084] The others are the same as in example 4.

[0085] Example 6

[0086] The difference between this example and Example 5 is that:

[0087] In step S5, the load B is a pretreated load B, and the preparation method of the pretreated load B comprises the following steps:

[0088] The load B is mixed with an ammonium molybdate solution with a molar concentration of 0.3 mol / L at a ratio of 1 g:0.5 mL, and then placed for 3 h. Then, it is transferred into a rotary evaporator (60 rpm, 50℃) for 2.5 h of vacuum impregnation, dried at 110℃ to constant weight, transferred into a sintering furnace, heated to 400℃ at a rate of 3℃, calcined for 2.5 h, and cooled to room temperature to obtain the pretreated load B.

[0089] The others are the same as in Example 5.

[0090] Example 7

[0091] The difference between this example and Example 6 is that:

[0092] S1: Dissolve 0.035 mol of cerium nitrate hexahydrate, 0.015 mol of lanthanum nitrate hexahydrate, 0.005 mol of zirconium nitrate pentahydrate, and 0.07 mol of glucose in 100 mL of deionized water to obtain solution A;

[0093] The others are the same as in Example 6.

[0094] Example 8

[0095] The difference between this example and Example 7 is that:

[0096] S1: Dissolve 0.035 mol of cerium nitrate hexahydrate, 0.015 mol of lanthanum nitrate hexahydrate, 0.01 mol of zirconium nitrate pentahydrate, and 0.07 mol of glucose in 100 mL of deionized water to obtain solution A;

[0097] The others are the same as in Example 7.

[0098] Comparative Example 1

[0099] The difference between this comparative example and Example 1 is that:

[0100] In step S1, an equimolar amount of citric acid is used to replace the glucose.

[0101] The others are the same as in Example 1.

[0102] Comparative Example 2

[0103] The preparation method of the rare earth metal oxide desulfurizer of this comparative example comprises the following steps:

[0104] S1: Dissolve 0.12 mol of copper nitrate hexahydrate, 0.04 mol of nickel nitrate hexahydrate and 0.024 mol of citric acid in 100 mL of deionized water to obtain solution A;

[0105] S2: Mix pre-sintered γ-Al2O3 with solution A at a ratio of 1 g:0.55 mL, stand for 4 h, place in a water bath, heat to 60℃, ultrasonic-assisted impregnation for 2 h at a power of 300 W and a frequency of 40 kHz, dry to constant weight at 110℃, transfer into a sintering furnace, heat to 500℃ at a rate of 3℃, sinter for 3 h, cool to room temperature in the furnace to obtain the support A;

[0106] S3: Dissolve 0.04 mol of cerium nitrate hexahydrate, 0.02 mol of lanthanum nitrate hexahydrate and 0.07 mol of glucose in 100 mL of deionized water to obtain solution B;

[0107] S4: Mix the support A with solution B at a ratio of 1 g:0.45 mL, stand for 2 h, then transfer into a rotary evaporator (60 rpm, 40℃), impregnate under reduced pressure for 2 h, dry to constant weight at 110℃, transfer into a sintering furnace, heat to 350℃ at a rate of 3℃, sinter for 3 h, cool to room temperature in the furnace to obtain the support B;

[0108] S5: Place the support B in a fixed bed reactor under a mixed atmosphere of H2 and N2, heat to 350℃ at a rate of 2℃, keep for 2 h, naturally cool to room temperature, then purge with N2 for 30 min to obtain the rare earth metal oxide desulfurizer.

[0109] The volume ratio of H2 to N2 is 10:90.

[0110] The preparation method of the pre-sintered γ-Al2O3 comprises the following steps:

[0111] Place γ-Al2O3 in a sintering furnace, heat to 500℃ at a rate of 5℃ / min, sinter for 4 h, cool to room temperature in the furnace, take the undersize through a 20 mesh standard sieve, take the oversize through a 40 mesh standard sieve to obtain the pre-sintered γ-Al2O3.

[0112] Performance detection test

[0113] 1. Preparation of simulated oil

[0114] Simulated oil A (mercaptan oil): total sulfur concentration 100 ppm (calculated as S), sulfur source is only tert-butyl mercaptan, solvent is n-octane; simulated oil B (thiophene oil): total sulfur concentration 100 ppm (calculated as S), sulfur source is only dibenzothiophene, solvent is n-octane; simulated oil C (mixed oil): total sulfur concentration 100 ppm, containing 50 ppm of tert-butyl mercaptan and 50 ppm of dibenzothiophene, solvent is n-octane.

[0115] 2. Detection steps

[0116] The rare earth metal oxide desulfurizer was sieved through a 40 mesh standard sieve, and 50 g of the sieve residue was loaded into a fixed bed reaction tube. After loading, the reaction tube was sealed at both ends with quartz wool, and nitrogen was introduced to check for leaks. The reaction tube was first purged with 50 mL / min of pure nitrogen for 30 min, then switched to a mixture of hydrogen and nitrogen at a volume ratio of 5:95, and heated to 200°C at a rate of 5°C / min. After 1 h at constant temperature, the hydrogen ratio was increased to 15:85, and the temperature was further increased to 380°C. After 2.5 h at constant temperature, the temperature was decreased to 320°C and held for 30 min,

[0117] The system was switched to pure hydrogen, and a high-pressure constant-flow pump was started to inject the simulated oil into the vaporization chamber at a rate of 90 mL / h (temperature 180°C). The system pressure was adjusted to 2.5 MPa, and the reaction temperature was 320°C. After the system temperature, pressure, and flow rate were stable, the timing was started, and the stable reaction phase was entered. Sampling and analysis were performed every 30-60 min, and each sampling was divided into two parts: one part was used to detect the product sulfur concentration (to determine the breakthrough point), and the other part was used to collect the product oil. The first sampling was completed within 30 min after the system stabilized. According to the national standard GB / T5487-2015, a research method octane number test machine was used to determine the RON values of the raw material simulated oil and the product oil in the stable reaction phase (sampling was performed at least 3 times), and the average value was taken as the final RON value. When the sulfur concentration of the product sampled for two consecutive times was ≥10 ppm, it was determined that the desulfurizer had reached the breakthrough point, and the reaction was immediately stopped. The high-pressure pump and H2 inlet valve were closed, switched to N2 at a flow rate of 50 mL / min, and the temperature was decreased to room temperature. After 30 min of continued purging, the pressure was released, and the cumulative running time t from the start of the stable reaction to the breakthrough point was recorded. The dynamic sulfur capacity was calculated, as shown in Table 1.

[0118] Table 1 Performance detection data of rare earth metal oxide desulfurizers prepared in Examples 1-8 and Comparative Examples 1-2

[0119]

[0120] As can be seen from Examples 1-4 and Comparative Examples 1-2, by first loading rare earth cerium and lanthanum and then loading transition metals copper and nickel, and selecting glucose as a dispersing aid, the cerium and lanthanum oxides can preferentially modify the surface of the γ-Al2O3 carrier, significantly improving the dispersity of the subsequent copper and nickel active phases, thereby improving the overall desulfurization performance of the desulfurizer. In Comparative Example 1, citric acid is used instead of glucose, and its strong complexation easily leads to premature agglomeration of the metal precursors, resulting in poorer performance than Example 1. In Comparative Example 2, the loading order is reversed, and the first loaded copper and nickel occupy a large number of active sites on the carrier surface, not only hindering the effective loading of rare earth oxides, but also destroying the synergistic effect between Ce / La and Cu / Ni, ultimately leading to a significant decrease in desulfurization performance.

[0121] In combinationFigures 1-2 The analysis shows that: Figure 1 In the figure, the characteristic peaks of Examples 1, 2 and 4 are relatively sharp, indicating that the active phase in the desulfurizer has good crystallinity. The peak intensity shows an optimization trend, reflecting that the dispersibility of the active phase is continuously improved with the process improvement. This is because glucose can effectively inhibit the agglomeration of metal precursors, and the sequence of first modifying the surface of γ-Al2O3 carrier with rare earth and then loading copper-nickel active phase not only ensures the effective loading and uniform dispersion of rare earth elements on the carrier surface, but also provides more suitable loading sites for the copper-nickel active phase, promoting the ordered formation of the active phase and strengthening the overall dispersibility. Although the diffraction peak of Comparative Example 2 is also relatively sharp, indicating that the active phase has a certain crystallinity, the intensity is relatively low. This is because it reverses the loading sequence of rare earth and copper-nickel active phase, and the effective sites available for rare earth modification on the carrier surface are reduced by loading copper-nickel first, making it difficult for rare earth to disperse effectively, and the improvement of active phase crystallinity and dispersibility is limited.

[0122] Figure 2 In the figure, the characteristic peak intensity of Example 4 is the highest, and that of Comparative Example 2 is the weakest, reflecting that the surface concentration and chemical state order of active elements are enhanced with process and component optimization; the modification of γ-Al2O3 carrier by cerium lanthanum oxide loaded first creates a more uniform loading environment for copper-nickel active phase, making copper-nickel more efficiently dispersed on the carrier surface and the chemical state more stable, ultimately improving the number and effective utilization rate of surface active sites. Due to the loading sequence problem, the surface concentration of active elements is low and the chemical state order is poor in Comparative Example 2, so the characteristic peak intensity is relatively weak.

[0123] Examples 5 and 6 use ammonium molybdate solution to post-treat the loaded material B, introducing Mo species with strong hydrogenation desulfurization activity, which significantly enhances the conversion capacity of difficult-to-remove dibenzothiophene, thereby greatly extending the running time of the desulfurizer and improving the sulfur capacity; Examples 7 and 8 introduce zirconium nitrate into the rare earth solution on the basis of molybdenum modification. The doping of Zr not only stabilizes the structure of γ-Al2O3 carrier and inhibits the agglomeration and sintering of active components during high-temperature treatment or reaction, but also produces a synergistic effect with rare earth and transition metals, further optimizing the dispersibility and intrinsic activity of the active phase by adjusting the surface acidity and electronic environment. This multi-component synergistic effect ultimately further enhances the removal performance and running stability of the desulfurizer for tert-butyl mercaptan, dibenzothiophene and their mixed systems, and the effect is better than that of Examples 5 and 6 which are only modified by Mo.

[0124] The specific embodiments are merely an explanation of the present application, which is not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for producing a rare earth metal oxide desulfurizer, characterized by, The method comprises the following steps: S1: dissolving cerium salt, lanthanum salt and glucose in water to obtain solution A; S2: impregnating, drying and calcining the pre-calcined γ-Al2O3 and solution A at a ratio of 1 g: (0.5-0.6) mL, at 300-400 ℃ for 2-4 h, and cooling to obtain the support A; S3: dissolving copper salt, nickel salt and citric acid in water to obtain solution B; S4: impregnating, drying and calcining the support A and solution B at a ratio of 1 g: (0.4-0.5) mL, at 450-550 ℃ for 2-4 h, and cooling to obtain the support B; S5: placing the support B in a reducing atmosphere, heating to 300-400 ℃, keeping for 2-3 h, and cooling to obtain the rare earth metal oxide desulfurizer.

2. The method for producing a rare earth metal oxide desulfurizer according to claim 1, characterized by, The total molar concentration of cerium salt and lanthanum salt in the solution A is 0.4-0.8 mol / L.

3. The preparation method of the rare earth metal oxide desulfurizing agent according to claim 1, characterized in that, The molar concentration of glucose in the solution A is (1-1.5) times the total molar number of cerium salt and lanthanum salt.

4. The method of claim 1, wherein the rare earth metal oxide desulfurizer is prepared by the steps of: The total molar concentration of copper salt and nickel salt in the solution B is 1-2 mol / L.

5. The method for preparing the rare earth metal oxide desulfurizing agent according to claim 1, characterized in that, In step S5, the support B is pretreated before use by the following steps: impregnating, drying and calcining the support B and ammonium molybdate solution at a ratio of 1 g: (0.5-0.6) mL, at 300-400 ℃ for 2-2.5 h, and cooling.

6. The method of claim 5 wherein the rare earth metal oxide desulfurizer is prepared by the steps of: The molar concentration of ammonium molybdate is 0.1-0.3 mol / L.

7. The method for preparing the rare earth metal oxide desulfurizing agent according to claim 1, characterized in that, The reducing atmosphere is a mixed atmosphere of H2 and N2, and the volume ratio of H2 to N2 in the mixed atmosphere is (10-15):(85-90).

8. The method of claim 1, wherein the rare earth metal oxide desulfurizer is prepared by the steps of: In step S1, a step of adding zirconium salt after the lanthanum salt is further included.

9. The method of claim 8, wherein the rare earth metal oxide desulfurizer is prepared by the steps of: (a) preparing a mixture of a rare earth metal oxide and a transition metal oxide; (b) mixing the mixture with a carrier; and (c) calcining the mixture. The amount of zirconium salt is (0.1-0.2) times the total molar number of lanthanum salt and cerium salt.

10. A rare earth metal oxide desulfurizer prepared by the method according to any one of claims 1-9.

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