Preparation method of aromatized gasoline hydrogenation deolefination catalyst

Abstract

The invention relates to a preparation method of an aromatized gasoline hydrogenation deolefination catalyst. The method mainly solves the problems of high content of precious metals required by a catalyst and complex preparation process in the process of removing olefins in aromatized gasoline at present. The preparation method is characterized by comprising the following steps: step 1, adding soluble silver salt to an alumina carrier by adopting an equivalent-volume impregnation method, and drying and roasting to obtain a silver-loaded alumina catalyst precursor; step 2, adding soluble palladium salt into the silver-loaded aluminum oxide catalyst precursor obtained in the step 1 by adopting an equivalent-volume impregnation method, and drying and roasting to obtain a palladium-silver-loaded aluminum oxide catalyst precursor; and step 3, reducing the palladium-silver-loaded alumina catalyst precursor to obtain the catalyst. The preparation method of the aromatized gasoline hydrogenation olefin removal catalyst has the characteristics of low noble metal content, simple preparation process, high selective hydrogenation activity in the use process, long service life and the like, is suitable for selective hydrogenation of aromatized gasoline to remove trace olefin, and has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of oil refining, and in particular to a method for preparing an aromatization gasoline hydrogenation deolefination catalyst. Background Art

[0002] Aromatics play an increasingly important role in the fields of petrochemicals, medicine, textiles, etc. In addition to catalytic reforming, separation from aromatized gasoline is also an important way to increase the production of aromatics. Since aromatized gasoline comes from a liquefied gas aromatization unit, it has a high olefin content and a high proportion of low-carbon olefins compared to conventional reforming oil. The presence of olefins will directly affect the stability of subsequent processes. Olefins are easily polymerized to form colloids, which in turn causes coking in the heat exchanger, deterioration of the sulfolane in the downstream extraction unit, deactivation of the catalyst and adsorbent in the disproportionation unit, and failure of the bromine index and acid washing colorimetry of the aromatic product. Therefore, the removal of olefins from aromatized gasoline is particularly important. The methods for removing olefins from aromatized gasoline and reforming oil are similar. Conventional removal methods include non-hydrogenation removal by clay / molecular sieve and hydrogenation catalyst hydroremoval. The hydroremoval process can be divided into a noble metal hydrogenation agent removal process and a non-noble metal hydrogenation agent removal process according to the type of active metal in the catalyst. Among them, precious metal hydrodeolefination catalysts have many advantages such as simple operation, long operating cycle, low product aromatic loss, and strong raw material adaptability. They have become the preferred solution for aromatization gasoline deolefination treatment and have broad application prospects.

[0003] CN200710177193.8 discloses a reforming oil hydrogenation catalyst and a preparation method thereof, wherein the main active metal components are Pd and one of Au, Ag, Pt, and Ir, and the auxiliary agent is one of Sn, Pb, Sb, and Bi. Inorganic acid or organic acid is used as a competitive adsorbent to adjust the pH value of the impregnation solution to 4 to 5 to obtain a catalyst with active metals distributed in an eggshell shallow layer.

[0004] CN201310345192.5 discloses a method for selective hydrogenation and deolefination of reforming oil, wherein the active component is at least one of Pt and Pt, the auxiliary agent is one or two of Sn and Pb, the carrier is alumina, and the precious metal is distributed in a thin eggshell shape on the carrier, and the eggshell thickness is 0.05~1mm. The specific surface area of ​​the catalyst is 50~400m2 / g, and the pore volume is 0.2~1.2cm3 / g, wherein the pores with a pore size of 5~50nm account for 50~80% of the total pores of the catalyst; the mass content of the active component is 0.05~0.5wt%, and the mass content of the auxiliary agent is 0.5~10%.

[0005] CN114471619A discloses a method for preparing a reforming oil hydrogenation deolefination catalyst: (1) impregnating an alumina carrier with an impregnation liquid containing an auxiliary agent, then drying the alumina carrier, and sulfiding the dried material to obtain a catalyst precursor; (2) preparing an impregnation liquid containing Pt and Pd, adjusting the pH value of the impregnation liquid to 3-5, and then impregnating the catalyst precursor obtained in step (1), drying the alumina carrier under an inert atmosphere, and then reducing the alumina carrier to obtain a reforming oil hydrogenation deolefination catalyst.

[0006] It is generally believed that a variety of catalysts and processes have been invented in the industry for removing trace olefins from reforming oil. However, compared with reforming oil, aromatized gasoline has a lower density and a higher content of low-carbon olefins. The existing reforming oil hydrogenation deolefination catalyst is directly used for aromatization gasoline deolefination. The catalyst bed temperature rises and carbon deposition is easy to occur, which can easily cause catalyst deactivation and directly affect the stable operation of the device. At the same time, the loss of aromatics during the operation is large, affecting the economy of the device. Summary of the invention

[0007] In order to overcome the shortcomings of the background technology, the present invention provides a method for preparing an aromatization gasoline hydrogenation deolefination catalyst, which mainly solves the problems of high precious metal content and complex preparation process required for the catalyst in the removal of olefins in aromatization gasoline.

[0008] The technical solution of the present invention is: A method for preparing a catalyst for hydrogenating and deolefinating aromatization gasoline, Step 1: adding a soluble silver salt to an alumina carrier by an equal volume impregnation method, and obtaining a silver-loaded alumina catalyst precursor through drying and calcination; Step 2: adding a soluble palladium salt to the silver-loaded alumina catalyst precursor obtained in step 1 by an equal volume impregnation method, and obtaining a palladium-silver-loaded alumina catalyst precursor through drying and calcination; Step 3: reducing the palladium-silver loaded alumina catalyst precursor to obtain a catalyst.

[0009] The soluble palladium salt is one or more of palladium nitrate, palladium chloride, ammonium chloropalladate, palladium acetate, and palladium acetylacetonate; The alumina carrier is one or more of γ-alumina, θ-alumina, and α-alumina.

[0010] In step 1, the drying temperature is 60-120° C., the drying time is 3-24 hours, the roasting temperature is 400-800° C., and the roasting time is 3-12 hours.

[0011] In step 2, the drying temperature is 60-120° C., the drying time is 3-24 hours, the roasting temperature is 400-800° C., and the roasting time is 3-12 hours.

[0012] In step 3, the reduction method is gas phase reduction in a mixed atmosphere of hydrogen and nitrogen.

[0013] In step 3, the volume content of hydrogen is 10% to 90%, and the rest is nitrogen.

[0014] In step 3, the volume content of hydrogen is 10% to 25%, and the rest is nitrogen.

[0015] In step 3, the reduction temperature is 350-500° C., and the reduction time is 2-12 hours.

[0016] The beneficial effects of the present invention are as follows: the present invention provides a method for preparing an aromatization gasoline hydrogenation deolefination catalyst, which has the characteristics of low precious metal content, simple preparation process, high selective hydrogenation activity during use, long service life, etc., is suitable for selective hydrogenation removal of trace olefins from aromatization gasoline, and has broad application prospects. DETAILED DESCRIPTION

[0017] The present invention is further described below: A method for preparing a catalyst for hydrogenating and deolefinating aromatization gasoline comprises the following steps: Step 1: adding a soluble silver salt to an alumina carrier by an equal volume impregnation method, and obtaining a silver-loaded alumina catalyst precursor through drying and calcination; Step 2: adding a soluble palladium salt to the silver-loaded alumina catalyst precursor obtained in step 1 by an equal volume impregnation method, and obtaining a palladium-silver-loaded alumina catalyst precursor through drying and calcination; Step 3: reducing the palladium-silver loaded alumina catalyst precursor to obtain a catalyst.

[0018] The soluble palladium salt is one or more of palladium nitrate, palladium chloride, ammonium chloropalladate, palladium acetate, and palladium acetylacetonate; The alumina carrier is one or more of γ-alumina, θ-alumina, and α-alumina.

[0019] In step 1, the drying temperature is 60-120° C., the drying time is 3-24 hours, the roasting temperature is 400-800° C., and the roasting time is 3-12 hours.

[0020] In step 2, the drying temperature is 60-120° C., the drying time is 3-24 hours, the roasting temperature is 400-800° C., and the roasting time is 3-12 hours.

[0021] In step 3, the reduction method is gas phase reduction in a mixed atmosphere of hydrogen and nitrogen.

[0022] In step 3, the volume content of hydrogen is 10% to 90%, and the rest is nitrogen.

[0023] In step 3, the volume content of hydrogen is 10% to 25%, and the rest is nitrogen.

[0024] In step 3, the reduction temperature is 350-500° C., and the reduction time is 2-12 hours.

[0025] An aromatization gasoline hydrodeolefination catalyst consists of an active component and a carrier, wherein the active components are palladium and silver, the palladium content is 0.2% to 0.5% and the silver content is 1% to 5% based on the weight of the catalyst, and the carrier is alumina.

[0026] Example 1 3.40g of silver nitrate was dissolved in 165mL of deionized water to obtain a silver nitrate aqueous solution, which was impregnated into 180g of a toothed spherical γ-alumina carrier with a water absorption rate of 92% by an equal volume impregnation method, and then dried at 120°C for 8h after being placed at room temperature for 1h, and calcined at 500°C for 6h to obtain a silver-loaded alumina catalyst precursor; 1.56g of palladium nitrate was dissolved in 165mL of deionized water to obtain a palladium nitrate aqueous solution, which was impregnated into the above silver-loaded alumina catalyst precursor by an equal volume impregnation method, and then dried at 120°C for 8h after being placed at room temperature for 1h, and calcined at 500°C for 6h to obtain a palladium-silver-loaded alumina catalyst precursor. It was then transferred to a tubular furnace, and a mixed gas with a volume content of 15% hydrogen and a volume content of 85% nitrogen was introduced, the air velocity was controlled to be 100h-1, and the catalyst was reduced at 350°C for 6h, and the catalyst was discharged after being purged with nitrogen to room temperature to obtain catalyst A.

[0027] Example 2 6.30g of silver nitrate was dissolved in 184mL of deionized water to obtain a silver nitrate aqueous solution, which was impregnated into 200g of a toothed spherical γ-alumina carrier with a water absorption rate of 92% by an equal volume impregnation method, and then dried at 120°C for 12h after being placed at room temperature for 2h, and calcined at 600°C for 4h to obtain a silver-loaded alumina catalyst precursor; 1.04g of palladium nitrate was dissolved in 184mL of deionized water to obtain a palladium nitrate aqueous solution, which was impregnated into the above silver-loaded alumina catalyst precursor by an equal volume impregnation method, and then placed at room temperature for 1h, and then dried at 120°C for 12h, and calcined at 600°C for 4h to obtain a palladium-silver-loaded alumina catalyst precursor. It was then transferred to a tubular furnace, and a mixed gas with a volume content of 20% hydrogen and a volume content of 80% nitrogen was introduced, the air velocity was controlled to be 50h-1, and the catalyst was reduced at 400°C for 6h, and the catalyst was discharged after nitrogen purging to room temperature to obtain catalyst B.

[0028] Example 3 6.30g of silver nitrate was dissolved in 130 mL of deionized water to obtain a silver nitrate aqueous solution, which was impregnated into 200g of a toothed spherical θ-alumina carrier with a water absorption rate of 65% by an equal volume impregnation method, and then dried at 100°C for 12h after being placed at room temperature for 2h, and calcined at 600°C for 6h to obtain a silver-loaded alumina catalyst precursor; 1.04g of palladium nitrate was dissolved in 130 mL of deionized water to obtain a palladium nitrate aqueous solution, which was impregnated into the above silver-loaded alumina catalyst precursor by an equal volume impregnation method, and then placed at room temperature for 1h, and then dried at 100°C for 12h, and calcined at 600°C for 6h to obtain a palladium-silver-loaded alumina catalyst precursor. It was then transferred to a tubular furnace, and a mixed gas with a volume content of 20% hydrogen and a volume content of 80% nitrogen was introduced, the air velocity was controlled to 50h-1, and the catalyst was reduced at 400°C for 8h, and the catalyst was discharged after nitrogen purging to room temperature to obtain catalyst C.

[0029] Example 4 4.72g of silver nitrate was dissolved in 30 mL of deionized water to obtain a silver nitrate aqueous solution, which was impregnated into 150g of a toothed spherical α-alumina carrier with a water absorption rate of 20% by an equal volume impregnation method, and then dried at 100°C for 18h after being placed at room temperature for 2h, and calcined at 800°C for 6h to obtain a silver-loaded alumina catalyst precursor; 0.78g of palladium nitrate was dissolved in 30 mL of deionized water to obtain a palladium nitrate aqueous solution, which was impregnated into the above silver-loaded alumina catalyst precursor by an equal volume impregnation method, and then placed at room temperature for 1h, and then dried at 100°C for 18h, and calcined at 800°C for 6h to obtain a palladium-silver-loaded alumina catalyst precursor. It was then transferred to a tubular furnace, and a mixed gas with a volume content of 15% hydrogen and a volume content of 85% nitrogen was introduced, the air velocity was controlled to be 100h-1, and the catalyst was reduced at 350°C for 4h, and the nitrogen was purged down to room temperature and then discharged to obtain catalyst D.

[0030] Example 5 9.44 g of silver nitrate was dissolved in 130 mL of deionized water to obtain a silver nitrate aqueous solution, which was impregnated into 200 g of a toothed spherical θ-alumina carrier with a water absorption rate of 65% by an equal volume impregnation method, and then dried at 60°C for 24 hours after being placed at room temperature for 2 hours, and calcined at 550°C for 8 hours to obtain a silver-loaded alumina catalyst precursor; 0.87 g of palladium nitrate was dissolved in 130 mL of deionized water to obtain a palladium nitrate aqueous solution, which was impregnated into the above silver-loaded alumina catalyst precursor by an equal volume impregnation method, and then dried at 60°C for 24 hours after being placed at room temperature for 2 hours, and calcined at 550°C for 8 hours to obtain a palladium-silver-loaded alumina catalyst precursor. It was then transferred to a tubular furnace, and a mixed gas with a volume content of 25% hydrogen and a volume content of 75% nitrogen was introduced, the air velocity was controlled to be 50h-1, and the catalyst was reduced at 500°C for 8 hours, and then discharged after nitrogen purging to room temperature to obtain catalyst E.

[0031] Example 6 7.56g of silver nitrate was dissolved in 104mL of deionized water to obtain a silver nitrate aqueous solution, which was impregnated into 160g of a toothed spherical θ-alumina carrier with a water absorption rate of 65% by an equal volume impregnation method, and then dried at 120°C for 6h after being placed at room temperature for 2h, and calcined at 550°C for 8h to obtain a silver-loaded alumina catalyst precursor; 0.76g of palladium nitrate was dissolved in 104mL of deionized water to obtain a palladium nitrate aqueous solution, which was impregnated into the above silver-loaded alumina catalyst precursor by an equal volume impregnation method, and then dried at 120°C for 6h after being placed at room temperature for 2h, and calcined at 550°C for 8h to obtain a palladium-silver-loaded alumina catalyst precursor. It was then transferred to a tubular furnace, and a mixed gas with a volume content of 10% hydrogen and a volume content of 90% nitrogen was introduced, the air velocity was controlled to 400h-1, and the catalyst was reduced at 500°C for 8h, and then discharged after nitrogen purging to room temperature to obtain catalyst F.

[0032] Example 7 6.30g of silver nitrate was dissolved in 104mL of deionized water to obtain a silver nitrate aqueous solution, which was impregnated into 160g of a toothed spherical θ-alumina carrier with a water absorption rate of 65% by an equal volume impregnation method, and then dried at 120°C for 6h after being placed at room temperature for 2h, and calcined at 600°C for 8h to obtain a silver-loaded alumina catalyst precursor; 0.69g of palladium chloride was dissolved in 104mL of deionized water to obtain a palladium chloride aqueous solution, which was impregnated into the above silver-loaded alumina catalyst precursor by an equal volume impregnation method, and then dried at 120°C for 6h after being placed at room temperature for 2h, and calcined at 600°C for 8h to obtain a palladium-silver-loaded alumina catalyst precursor. It was then transferred to a tubular furnace, and a mixed gas with a volume content of 10% hydrogen and a volume content of 90% nitrogen was introduced, the air velocity was controlled to be 400h-1, and the catalyst was reduced at 400°C for 6h, and the catalyst was discharged after nitrogen was purged to room temperature to obtain catalyst G.

[0033] Example 8 7.56g of silver nitrate was dissolved in 104mL of deionized water to obtain a silver nitrate aqueous solution, which was impregnated into 160g of a toothed spherical θ-alumina carrier with a water absorption rate of 65% by an equal volume impregnation method, and then dried at 120°C for 6h after being placed at room temperature for 2h, and calcined at 550°C for 12h to obtain a silver-loaded alumina catalyst precursor; 0.69g of palladium chloride was dissolved in 104mL of deionized water to obtain a palladium chloride aqueous solution, which was impregnated into the above silver-loaded alumina catalyst precursor by an equal volume impregnation method, and then dried at 120°C for 6h after being placed at room temperature for 2h, and calcined at 550°C for 12h to obtain a palladium-silver-loaded alumina catalyst precursor. It was then transferred to a tubular furnace, and a mixed gas with a volume content of 15% hydrogen and a volume content of 85% nitrogen was introduced, the air velocity was controlled to be 200h-1, and the catalyst was reduced at 350°C for 10h, and the catalyst was discharged after nitrogen was purged to room temperature to obtain catalyst H.

[0034] Example 9 6.04 g of silver nitrate was dissolved in 104 mL of deionized water to obtain a silver nitrate aqueous solution, which was impregnated into 160 g of a toothed spherical θ-alumina carrier with a water absorption rate of 65% by an equal volume impregnation method, and then dried at 120°C for 6 hours after being placed at room temperature for 2 hours, and calcined at 600°C for 3 hours to obtain a silver-loaded alumina catalyst precursor; 0.81 g of palladium acetate was dissolved in 104 mL of deionized water to obtain a palladium acetate aqueous solution, which was impregnated into the above silver-loaded alumina catalyst precursor by an equal volume impregnation method, and then dried at 120°C for 6 hours after being placed at room temperature for 2 hours, and calcined at 600°C for 3 hours to obtain a palladium-silver-loaded alumina catalyst precursor. It was then transferred to a tubular furnace, and a mixed gas with a volume content of 20% hydrogen and a volume content of 80% nitrogen was introduced, the air velocity was controlled to be 100h-1, and the catalyst was reduced at 400°C for 2 hours, and the catalyst was discharged after nitrogen was purged to room temperature to obtain catalyst I.

[0035] Example 10 Catalysts A~I prepared in Examples 1~9 and commercial industrial catalysts for selective hydrodeolefination of reforming oil were selected as reference agents to evaluate the selective hydrodeolefination performance of aromatized gasoline. The evaluation feedstock oil used was aromatized gasoline provided by a refinery, wherein the bromine index was 4200~4500 mgBr / 100g. The evaluation device used a 10mL fixed bed hydrogenation device to evaluate the hydrodeolefination performance of aromatized gasoline for catalysts A~I and the reference agent, respectively. The reaction temperature was controlled at 115°C, the inlet pressure of the reactor was 2.0 MPa, the feed rate of aromatized gasoline was 60 mL / h, and the hydrogen / oil volume ratio was 15.

[0036] The evaluation results of each catalyst are shown in the following table. It can be seen from the evaluation results in the table that under the above evaluation conditions, compared with the industrial reference agent, the catalyst of the present invention can maintain a higher activity for a long time in the selective hydrogenation reaction of olefins in aromatized gasoline.

[0037]

[0038] The embodiments described are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention. The embodiments should not be regarded as limiting the present invention, but any improvements made based on the spirit of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing an aromatization gasoline hydrodeolefination catalyst, characterized in that: The following steps are included: Step 1: adding a soluble silver salt to an alumina carrier by an equal volume impregnation method, and obtaining a silver-loaded alumina catalyst precursor through drying and calcination; Step 2: adding a soluble palladium salt to the silver-loaded alumina catalyst precursor obtained in step 1 by an equal volume impregnation method, and obtaining a palladium-silver-loaded alumina catalyst precursor through drying and calcination; Step 3: reducing the palladium-silver loaded alumina catalyst precursor to obtain a catalyst.

2. The method for preparing an aromatized gasoline hydrodeolefination catalyst according to claim 1, characterized in that: The soluble palladium salt is one or more of palladium nitrate, palladium chloride, ammonium chloropalladate, palladium acetate, and palladium acetylacetonate.

3. The method for preparing an aromatization gasoline hydrodeolefination catalyst according to claim 1, characterized in that: The alumina carrier is one or more of γ-alumina, θ-alumina, and α-alumina.

4. The method for preparing an aromatization gasoline hydrodeolefination catalyst according to claim 1, characterized in that: In step 1, the drying temperature is 60-120° C., the drying time is 3-24 hours, the roasting temperature is 400-800° C., and the roasting time is 3-12 hours.

5. The method for preparing an aromatization gasoline hydrodeolefination catalyst according to claim 1, characterized in that: In step 2, the drying temperature is 60-120° C., the drying time is 3-24 hours, the roasting temperature is 400-800° C., and the roasting time is 3-12 hours.

6. A method for preparing an aromatization gasoline hydrodeolefination catalyst according to any one of claims 1 to 5, characterized in that: In step 3, the reduction method is gas phase reduction in a mixed atmosphere of hydrogen and nitrogen.

7. The method for preparing an aromatization gasoline hydrodeolefination catalyst according to claim 6, characterized in that: In step 3, the volume content of hydrogen is 10% to 25%, and the rest is nitrogen.

8. The method for preparing an aromatization gasoline hydrodeolefination catalyst according to claim 7, characterized in that: In step 3, the reduction temperature is 350-500° C., and the reduction time is 2-12 hours.

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