Desulfurization adsorbents, methods of making and using the same

Abstract

The present application relates to the technical field of adsorbent, in particular to a desulfurization adsorbent and its preparation method and application. 表面金属 / W 表面载体 The ratio of W 总金属 / W 总载体 of the adsorbent is above 4. The desulfurization adsorbent provided by the present application has high metal content on the outer surface and low metal content in the pore channel, thereby avoiding the activity reduction caused by the pore channel blockage and having higher activity recovery rate after regeneration. The desulfurization adsorbent provided by the present application is particularly suitable for benzene desulfurization, and the desulfurization adsorbent is used for general benzene raw material and has high activity recovery rate after regeneration; the desulfurization adsorbent is used for deep benzene desulfurization and has sulfur capacity above 0.80 g of thiophene per kg of adsorbent.

Description

Technical Field

[0001] This invention relates to the field of adsorbent technology, specifically to a desulfurization adsorbent, its preparation method, and its application. Background Technology

[0002] Currently, the hydrogenation of benzene to cyclohexene is an important industrial process for producing cyclohexene. This process uses ruthenium as a catalyst, thus requiring a very high sulfur content in the raw benzene; otherwise, the catalyst will be rapidly poisoned and deactivated. To ensure long-term operation of the unit, the sulfur content in benzene must be below 0.1 ppm or even lower. Currently, hydrodesulfurization and adsorption desulfurization are commonly used industrially. However, conventional hydrodesulfurization or adsorption desulfurization can no longer meet the requirements for deep benzene desulfurization because the sulfur content in petroleum benzene is already above 1 ppm.

[0003] CN103041766A and CN109499534A both disclose a benzene deep desulfurization adsorbent using palladium as the active component, which can reduce the sulfur content in benzene to 0.01 ppm. However, palladium metal is extremely expensive, resulting in a high cost for the adsorbent. CN104941570A discloses a ruthenium-containing benzene deep desulfurization adsorbent, which significantly reduces the cost of the adsorbent and has a good desulfurization effect. However, this method has poor ruthenium metal particle dispersion, and the ruthenium metal content used is above 0.8% by weight, which still results in a relatively high cost. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a desulfurization adsorbent, its preparation method, and its application. The desulfurization adsorbent provided by this invention has a significantly increased surface metal content, which reduces the enrichment of metal in the pores of the desulfurization adsorbent and avoids rapid deactivation caused by pore blockage.

[0005] To achieve the above objectives, the present invention provides a desulfurization adsorbent comprising a support and a metal loaded on the support, wherein the W layer on the outer surface of the adsorbent reaches a depth of 10-20 nm. 表面金属 / W 表面载体 With the W of the adsorbent 总金属 / W 总载体 The ratio is above 4.

[0006] A second aspect of the present invention provides a method for preparing the adsorbent of the present invention, the method comprising:

[0007] (1) Prepare an aqueous solution of the metal salt with a concentration of 0.1 g / mL or higher;

[0008] (2) Impregnate an organic amine onto a carrier in equal volume;

[0009] (3) Spray the aqueous solution obtained in step (1) onto the surface of the carrier obtained in step (2), then stir, optionally let stand, vacuum dry or dry in an inert gas atmosphere, calcine in an inert gas atmosphere, or reduce.

[0010] A third aspect of the present invention provides an application of the desulfurization adsorbent described in the present invention in benzene desulfurization, preferably in the application of deep benzene desulfurization.

[0011] The desulfurization adsorbent provided by this invention has a high metal content on its outer surface and a low metal content in its pores, avoiding the activity decrease caused by pore blockage and resulting in a higher activity recovery rate after regeneration. This desulfurization adsorbent is particularly suitable for benzene desulfurization. When used with general benzene feedstock, it exhibits a high activity recovery rate after regeneration; for deep benzene desulfurization, its sulfur capacity is above 0.80 g thiophene / kg adsorbent. This is presumably because the preparation method provided by this invention first impregnates the carrier with an equal volume of organic amine, filling its pores with alkaline organic matter. This prevents the diffusion of metal ions into the pores, allowing them to rapidly deposit on the outer surface of the adsorbent carrier, reducing the metal content in the pores and enriching the metal on the outer surface of the adsorbent. Detailed Implementation

[0012] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0013] This invention provides a desulfurization adsorbent containing a support and a metal loaded on the support, wherein the W on the outer surface of the adsorbent reaches a depth of 10-20 nm. 表面金属 / W 表面载体 With the W of the adsorbent 总金属 / W 总载体 The ratio is above 4; the desulfurization adsorbent provided by this invention has a high metal content on the outer surface and a low metal content in the pores, which avoids the decrease in activity caused by pore blockage and has a higher activity recovery rate after regeneration.

[0014] In this invention, there is no particular limitation on the metal. Any metal used for desulfurization adsorption in the art can be used as the metal described in this invention. Preferably, the metal is a noble metal, more preferably one or more of Ru, Pt, and Pd, and more preferably Ru.

[0015] According to a preferred embodiment of the present invention, the W layer on the outer surface of the adsorbent reaches a depth of 10-20 nm. 表面金属 / W 表面载体 With the W of the adsorbent总金属 / W 总载体 The ratio is 4.5-8; this is beneficial for improving the overall performance of the desulfurization adsorbent.

[0016] In this invention, the W 表面金属 / W 表面载体 This refers to the weight ratio of the metal on the outer surface of the adsorbent to a depth of 10-20 nm to the carrier.

[0017] In this invention, the W 总金属 / W 总载体， The weight ratio of total metal in the adsorbent to the carrier.

[0018] According to the present invention, W 表面金属 / W 表面载体 With the W of the adsorbent 总金属 / W 总载体 The ratio is abbreviated as surface metal enrichment / total metal enrichment.

[0019] In this invention, there is no particular limitation on the carrier, which can be a conventional carrier in the art. Preferably, the carrier is one or two of alumina and silicon oxide, with alumina being the most preferred.

[0020] According to a preferred embodiment of the present invention, the adsorbent contains, by weight, 90-99.9% carrier and 0.1-10% metal, which is beneficial to improving the overall performance of the desulfurization adsorbent.

[0021] All desulfurization adsorbents possessing the aforementioned properties can achieve the objectives of this invention. This invention does not particularly limit the preparation method of the desulfurization adsorbent; however, this invention provides a method for preparing the desulfurization adsorbent described herein, comprising:

[0022] (1) Prepare an aqueous solution of the metal salt with a concentration of 0.1 g / mL or higher;

[0023] (2) Impregnate an organic amine onto a carrier in equal volume;

[0024] (3) Spray the aqueous solution obtained in step (1) onto the surface of the carrier obtained in step (2), then stir, optionally let stand, vacuum dry, or dry in an inert gas atmosphere, calcine in an inert gas atmosphere, or reduce. In this invention, the carrier is first impregnated with an equal volume of organic amine to fill its pores with alkaline organic matter, which avoids the diffusion of metal ions into the pores and allows them to be rapidly deposited on the outer surface of the adsorbent carrier, reducing the metal content in the pores and enriching the metal on the outer surface of the adsorbent.

[0025] In this invention, there is no sequential order in steps (1) and (2), which is mainly used to express distinction.

[0026] According to a preferred embodiment of the present invention, the metal content in the high-concentration aqueous solution in step (1) is 0.1 to 0.5 grams per milliliter.

[0027] According to a preferred embodiment of the present invention, in step (2), the boiling point of the organic amine is below 100°C, which is beneficial to increasing the amount of metal ions deposited on the surface of the carrier.

[0028] According to a preferred embodiment of the present invention, in step (2), the organic amine includes one or more of diethylamine, triethylamine, propylamine, and butylamine, which is beneficial to further increase the deposition amount of metal ions on the carrier surface.

[0029] According to a preferred embodiment of the present invention, the organic amine is diethylamine, which is beneficial to further increase the deposition amount of metal ions on the carrier surface.

[0030] According to a preferred embodiment of the present invention, in step (3), the settling time is 0.5 to 12 hours.

[0031] According to a preferred embodiment of the present invention, in step (3), the conditions for vacuum drying include: a drying temperature of 0 to 60°C, and a drying time that is reasonably adjusted according to the drying temperature. Preferably, the drying time is 0.5 to 12 hours.

[0032] According to a preferred embodiment of the present invention, in step (3), the drying conditions in the inert gas atmosphere include: an inert gas flow rate of 50-200 mL / min, a drying temperature of 80-120°C, and a drying time of 0.5-12 hours.

[0033] In this invention, the inert gas is a conventional inert gas in the art, such as nitrogen or one or more other rare gases.

[0034] According to a preferred embodiment of the present invention, in step (3), the reduction conditions include: being carried out in a hydrogen atmosphere, a reduction temperature of 100–400°C, and a hydrogen volume hourly space velocity of 20–40 h⁻¹. -1 The restoration time is 3 to 10 hours.

[0035] This invention provides an application of the desulfurization adsorbent described herein in benzene desulfurization. Compared with the prior art, the desulfurization adsorbent described herein, when used with general benzene raw materials, exhibits a higher activity recovery rate after regeneration.

[0036] According to a preferred embodiment of the present invention, the desulfurization adsorbent of the present invention is used for deep desulfurization of benzene. The desulfurization adsorbent provided by the present invention is particularly suitable for benzene desulfurization. The desulfurization adsorbent is used for general benzene raw materials and has a high activity recovery rate after regeneration. It is used for deep desulfurization of benzene and has a sulfur capacity of more than 0.80 g thiophene / kg adsorbent.

[0037] It should be noted that the two or more aspects (or embodiments) disclosed in the context of this specification can be arbitrarily combined with each other, and the resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of this invention.

[0038] In this invention, the metal content within a depth of 10-20 nm on the outer surface of the adsorbent was determined by X-ray photoelectron spectroscopy. The instrument used was a Thermo Fisher K-Alpha spectrometer, with an optimal resolution of <30 μm, an optimal energy resolution of <0.5 eV FWHM, and a C1s energy resolution of <0.85 eV. An Al Kα target (hν = 1486.68 eV) was used, with an ion source energy range of 100 to 3 keV, a maximum beam current of 4 μA, and an optimal vacuum of 5 × 10⁻⁶ Ω·cm in the analysis chamber. -9 mbar.

[0039] Example 1

[0040] (1) Prepare an aqueous solution of ruthenium chloride with 0.2 g ruthenium per milliliter;

[0041] (2) Take 100g of alumina carrier and add 60ml of triethylamine for impregnation;

[0042] (3) Spray 3 mL of a ruthenium chloride aqueous solution containing 0.2 g ruthenium per mL onto the above alumina support, stir thoroughly for 0.5 hours, and let stand for 6 hours; then vacuum dry at 40 °C for 5 hours, calcine at 550 °C for 5 hours under a nitrogen atmosphere, and finally calcine at 300 °C with a hydrogen volume hourly space velocity of 30 h⁻¹. -1 After reduction for 4 hours, adsorbent A was obtained. The ruthenium metal content on its surface was analyzed, and the results are shown in Table 1.

[0043] Example 2

[0044] (1) Prepare an aqueous solution of ruthenium chloride with 0.2 g ruthenium per milliliter;

[0045] (2) Take 100g of alumina carrier and add 60ml of diethylamine for impregnation;

[0046] (3) Spray 3 mL of a ruthenium chloride aqueous solution containing 0.2 g ruthenium per mL onto the above alumina support, stir thoroughly for 0.5 hours, and let stand for 6 hours; then vacuum dry at 40 °C for 5 hours, calcine at 550 °C for 5 hours under a nitrogen atmosphere, and finally calcine at 300 °C with a hydrogen volume hourly space velocity of 30 h⁻¹. -1 After reduction for 4 hours, adsorbent B was obtained. The ruthenium metal content on its surface was analyzed, and the results are shown in Table 1.

[0047] Example 3

[0048] (1) Prepare an aqueous solution of ruthenium chloride with 0.2 g ruthenium per milliliter;

[0049] (2) Take 100g of alumina carrier and add 60ml of butylamine for impregnation;

[0050] (3) Spray 3 mL of a ruthenium chloride aqueous solution containing 0.2 g ruthenium per mL onto the above alumina support, stir thoroughly for 0.5 hours, and let stand for 6 hours; then dry at 120 °C with a nitrogen flow rate of 100 mL / min for 5 hours, calcine at 550 °C with a nitrogen atmosphere for 5 hours, and finally calcine at 300 °C with a hydrogen volume hourly space velocity of 30 h⁻¹. -1 After reduction for 4 hours, the adsorbent C was obtained. The ruthenium metal content on its surface was analyzed, and the results are shown in Table 1.

[0051] Example 4

[0052] (1) Prepare an aqueous solution of palladium nitrate with a concentration of 0.2 g palladium per milliliter;

[0053] (2) Take 100g of alumina carrier and add 60ml of butylamine for impregnation;

[0054] (3) Spray 3 mL of a palladium nitrate aqueous solution (0.2 g palladium per mL) onto the above-mentioned alumina support, stir thoroughly for 0.5 hours, and let stand for 6 hours; then vacuum dry at 40 °C for 5 hours, calcine at 550 °C for 5 hours under a nitrogen atmosphere, and finally calcine at 300 °C with a hydrogen volume hourly space velocity of 30 h⁻¹. -1 After reduction for 4 hours, the adsorbent D was obtained. The surface palladium metal content was analyzed, and the results are shown in Table 1.

[0055] Example 5

[0056] Compared with Example 1, the difference is that in step (2), alumina is replaced with a mixture of 90% alumina and 10% silica; the remaining conditions are the same as in Example 1, and the adsorbent E is obtained.

[0057] Example 6

[0058] (1) Prepare an aqueous solution of ruthenium chloride with 0.1 g ruthenium per milliliter;

[0059] (2) Take 100g of alumina carrier and add 60ml of triethylamine for impregnation;

[0060] (3) Spray 6 mL of a ruthenium chloride aqueous solution containing 0.1 g ruthenium per mL onto the above alumina support, stir thoroughly for 1 hour, and let stand for 6 hours; then vacuum dry at 45 °C for 4 hours, calcine at 500 °C for 6 hours under a nitrogen atmosphere, and finally calcine at 280 °C with a hydrogen volume hourly space velocity of 60 h⁻¹. -1After reduction for 3 hours, the adsorbent F was obtained. The ruthenium metal content on its surface was analyzed, and the results are shown in Table 1.

[0061] Example 7

[0062] (1) Prepare an aqueous solution of ruthenium chloride with 0.5 g ruthenium per milliliter;

[0063] (2) Take 100g of alumina carrier and add 60ml of diethylamine for impregnation;

[0064] (3) Spray 6 mL of a ruthenium chloride aqueous solution containing 0.1 g ruthenium per mL onto the above alumina support, stir thoroughly for 1 hour, and let stand for 6 hours; then vacuum dry at 45 °C for 4 hours, calcine at 500 °C for 6 hours under a nitrogen atmosphere, and finally calcine at 280 °C with a hydrogen volume hourly space velocity of 60 h⁻¹. -1 After reduction for 3 hours, the adsorbent G was obtained. The ruthenium metal content on its surface was analyzed, and the results are shown in Table 1.

[0065] Comparative Example 1

[0066] (1) Prepare a ruthenium chloride aqueous solution with 0.01 g ruthenium per milliliter. (2) Take 100 g of alumina support, add 60 mL of the ruthenium chloride aqueous solution prepared in step (1), stir thoroughly for 0.5 hours, and let stand for 6 hours. Then dry at 120 °C for 5 hours, calcine at 550 °C for 5 hours under a nitrogen atmosphere, and finally calcine at 300 °C with a hydrogen volume hourly space velocity of 30 h⁻¹. -1 After reduction for 4 hours, the adsorbent H was obtained. The ruthenium metal content on its surface was analyzed, and the results are shown in Table 1.

[0067] Test Example 1

[0068] Sulfur capacity and pore volume were measured for Examples 1-7 and Comparative Example 1. The sulfur capacity measurement method included: using a fixed-bed continuous feed, the benzene feedstock containing 1 ppm thiophene, the reaction temperature being 150°C, the pressure being 1.0 MPa, the desulfurization adsorbent loading being 35 g, and the mass hourly space velocity being 4 h⁻¹. -1 The evaluation time was based on the subsequent periodic determination of the thiophene content in the benzene at the reactor outlet. Generally, when the outlet content was greater than 100 ppb, the feed was stopped and the sulfur capacity was calculated. After testing, the adsorbent was purged with nitrogen and regenerated by calcination at 550℃ for 5 hours. The pore volume was then tested by nitrogen physical adsorption. The results are shown in Tables 1 and 2.

[0069] Test Example 2

[0070] The sulfur capacity of the regenerated adsorbent obtained in Test Example 1 was tested again. The sulfur capacity determination method was as follows: a fixed-bed continuous feed was used, the benzene feedstock contained 1 ppm thiophene, the reaction temperature was 150℃, the pressure was 1.0 MPa, the adsorbent loading was 35 g, and the mass hourly space velocity (WHSV) was 4 h⁻¹.-1 The evaluation time was based on the subsequent periodic determination of the thiophene content in the benzene at the reactor outlet. Generally, when the outlet content was greater than 100 ppb, the feed was stopped and the sulfur capacity was calculated. After testing, the adsorbent was purged with nitrogen and calcined at 550℃ for 5 hours. The pore volume was then tested by nitrogen physical adsorption. The results are shown in Tables 1 and 2.

[0071] Table 1

[0072]

[0073] Sulfur capacity, g thiophene / kg adsorbent. Adsorbent refers to the weight of sulfur adsorbed per kilogram of adsorbent, expressed as thiophene.

[0074] The sulfur capacity after regeneration, g thiophene / kg adsorbent, refers to the weight of sulfur adsorbed per kilogram of regenerated adsorbent, expressed as thiophene.

[0075] In Table 1, W 表面金属 / W 表面载体 With the W of the adsorbent 总金属 / W 总载体 The ratio is abbreviated as surface metal enrichment / total metal enrichment; the weight content of metals from the outer surface of the adsorbent to a depth of 10-20 nm is expressed as surface metal content.

[0076] As shown in Table 1, the sulfur capacity and surface metal content of each adsorbent in the examples are significantly higher than those in the comparative examples. After regeneration, the sulfur capacity of the adsorbents in the examples is basically the same as that of the original adsorbents, while the sulfur capacity of the adsorbents in the comparative examples decreases significantly after regeneration.

[0077] Table 2. Pore volume changes of each adsorbent

[0078]

[0079] As shown in Table 2, the pore volume of each adsorbent in the examples decreased significantly after use, but recovered after regeneration.

[0080] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. The application of desulfurization adsorbent in benzene desulfurization, characterized in that, The adsorbent contains a support and a metal loaded on the support, wherein the W on the outer surface of the adsorbent extends to a depth of 10-20 nm. 表面金属 / W 表面载体 With the W of the adsorbent 总金属 / W 总载体 The ratio is 4-8; the metal is one or more of Ru, Pt, and Pd; the sulfur capacity of the adsorbent is above 0.80 g thiophene / kg adsorbent.

2. The application according to claim 1, wherein, W on the outer surface of the adsorbent to a depth of 10-20 nm 表面金属 / W 表面载体 With the W of the adsorbent 总金属 / W 总载体 The ratio is 4.5-8.

3. The application according to claim 1, wherein, The metal is Ru.

4. The application according to claim 1, wherein, The carrier is one or both of alumina and silicon dioxide.

5. The application according to claim 4, wherein, The carrier is aluminum oxide.

6. The application according to claim 1, wherein, The adsorbent contains, by weight, 90-99.9% carrier and 0.1-10% metal.

7. The application according to any one of claims 1-6, wherein, Methods for preparing desulfurization adsorbents include: (1) Prepare an aqueous solution of the metal salt with a concentration of 0.1 g / mL or higher; (2) Impregnate an organic amine onto a carrier in equal volume; (3) Spray the aqueous solution obtained in step (1) onto the surface of the carrier obtained in step (2), then stir, optionally let stand, vacuum dry or dry in an inert gas atmosphere, calcine in an inert gas atmosphere, or reduce.

8. The application according to claim 7, wherein, The metal content in the aqueous solution described in step (1) is 0.1 to 0.5 grams per milliliter.

9. The application according to claim 7, wherein, The organic amine described in step (2) has a boiling point below 100°C.

10. The application according to claim 9, wherein, The organic amine mentioned in step (2) includes one or more of diethylamine, triethylamine, propylamine, and butylamine, or a mixture thereof.

11. The application according to claim 10, wherein, The organic amine is diethylamine.

12. The application according to claim 7, wherein, In step (3), The settling time is 0.5 to 12 hours; and / or Vacuum drying conditions include: drying temperature of 0~60℃ and drying time of 0.5~12 hours; The drying conditions in an inert gas atmosphere include: an inert gas flow rate of 50-200 mL / min, a drying temperature of 80-120℃, and a drying time of 0.5-12 hours.

13. The application according to claim 7, wherein, In step (3), the conditions for restoration include: The reduction was carried out under a hydrogen atmosphere at a temperature of 100–400 °C and a hydrogen volume hourly space velocity of 20–40 h⁻¹. -1 The restoration time is 3 to 10 hours.

14. The application according to claim 1, wherein, The benzene desulfurization is a deep benzene desulfurization.

Images