A stationary phase for separating asphalt hydrocarbon components, an extraction column and a method of use

Abstract

The application discloses a kind of fixed phase for separating asphalt hydrocarbon components, extraction column and application method.The fixed phase is silver ion loaded alumina, which is prepared by the following method: uniformly mixing alumina with silver salt solution, adding urea and uniformly mixing by ultrasonic, then sealed dynamic impregnation, impregnation time is 2-6h, impregnation temperature is 80-90 DEG C, after impregnation, continue stirring until the solution is evaporated, vacuum drying, to obtain the fixed phase.Adopting the fixed phase of the application as the lower fixed phase, using alumina and silica mixture as the upper fixed phase as the extraction column, can accurately and reasonably separate asphalt into eight components, wherein the sub-components of aromatic fraction and colloid can be separated according to better aromaticity, while improving the yield of each component, effectively avoiding column loss, and silver ions are not easy to elute.

Description

Technical Field

[0001] This invention relates to a stationary phase, extraction column, and application method for separating asphalt hydrocarbon components. Background Technology

[0002] Asphalt is an important road transportation material, understanding its internal composition is crucial for road engineering research, development, and design. Currently, the petrochemical industry commonly uses the NB / SH / T 0509 method to analyze the four components of asphalt. First, asphaltenes are precipitated with n-heptane. Then, the deasphalted portion is adsorbed onto an alumina column and eluted sequentially with n-heptane, toluene, and toluene-ethanol to obtain saturated fractions, aromatic fractions, and resins, respectively. However, this four-component separation method lacks precision, especially due to severe cross-linking among aromatics, resulting in poor separation. It can only seek general patterns in the composition and properties of asphalt, making it difficult to analyze the intrinsic relationship between polar components and macroscopic properties at the molecular level. This method uses 1% water to deactivate the alumina to reduce column loss, which easily leads to uneven column distribution and low yield. Moreover, the small sample throughput and low column yield are unfavorable for further detection, analysis, and performance evaluation.

[0003] CN102079987A discloses a method for separating heavy oil components using solid-phase extraction, including the step of contacting heavy oil with a stationary phase, wherein the stationary phase comprises silver-ion-loaded silica and alumina. This method separates heavy oil into three components: saturated hydrocarbons, aromatics, and gums through solid-phase extraction. CN105251437A discloses a stationary phase for solid-phase extraction of hydrocarbon components in heavy oil, which is silver-ion-loaded alumina, with the loaded silver ions accounting for 0.5-12% of the alumina mass. This stationary phase is used for extracting and separating heavy oil, which can separate heavy oil into five components: saturated hydrocarbon components, light aromatic hydrocarbon components, medium aromatic hydrocarbon components, heavy aromatic hydrocarbon components, and gums. Ag is present in the above methods. + It suffers from easy loss and the separation accuracy needs to be improved. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a stationary phase, extraction column, and application method for separating hydrocarbon components in asphalt. Using the stationary phase of this invention as the lower stationary phase and a mixture of alumina and silica as the upper stationary phase in the extraction column, asphalt can be accurately and rationally separated into eight components. The aromatic and resinous sub-components can be separated effectively based on their aromaticity, while simultaneously increasing the yield of each component, effectively avoiding column loss, and minimizing the elution of silver ions.

[0005] The first aspect of the present invention provides a stationary phase for separating asphalt hydrocarbon components, wherein the stationary phase is alumina loaded with silver ions, and is prepared by the following method: alumina is mixed evenly with a silver salt solution, urea is added and ultrasonically mixed evenly, and then the mixture is dynamically impregnated in a sealed manner for 2 to 6 hours at an impregnation temperature of 80 to 90°C. After impregnation, the mixture is left open and stirred until the solution evaporates to dryness, and then vacuum dried to obtain the stationary phase.

[0006] Furthermore, based on the mass of alumina, the mass content of silver is 1% to 10%.

[0007] Furthermore, in the method for preparing the stationary phase, the silver salt can be a soluble silver salt, such as at least one of silver nitrate and silver sulfate, preferably silver nitrate, and the concentration of the silver salt solution is 0.01 to 0.20 g / mL.

[0008] Furthermore, in the method for preparing the stationary phase, the molar ratio of urea to silver is 1:4 to 4:1.

[0009] Furthermore, in the method for preparing the stationary phase, the mixing method is ultrasonic mixing, and the ultrasonic conditions are: power of 100-300W, frequency of 30-50Hz, mixing temperature of 20-40℃, and mixing time of 30-60min.

[0010] Furthermore, the alumina is neutral alumina with a particle size of 100-200 mesh and a specific surface area of ​​100-300 m². 2 / g. The alumina is calcined alumina, preferably calcined at a temperature of 400-550°C for 4-8 hours.

[0011] Furthermore, in the method for preparing the stationary phase, the stirring rate of the closed dynamic impregnation is 500-800 rpm / min.

[0012] Furthermore, in the method for preparing the stationary phase, the vacuum drying temperature is 120–180°C, the vacuum degree is 90–95 kPa, and the drying time is 1–10 h.

[0013] The extraction column for separating pitch hydrocarbon components provided by the second aspect of the present invention includes an upper stationary phase and a lower stationary phase described in the first aspect, which are packed in series. The upper stationary phase is a mixture of alumina and silica, wherein the silica content is 20% to 40% by mass.

[0014] Furthermore, the alumina in the upper stationary phase is neutral alumina with a particle size of 100-200 mesh and a specific surface area of ​​100-300 m². 2 / g. The alumina is calcined alumina, calcined at a temperature of 400–550°C for 4–8 hours.

[0015] Furthermore, the silica in the upper stationary phase is selected from silica gel, with a particle size of 100-200 mesh and a specific surface area of ​​200-400 m². 2 / g.

[0016] Furthermore, the mixture of alumina and silica as the upper stationary phase is preferably prepared by the following method: alumina, silica, and deionized water are mixed, then stirred until the solution evaporates to dryness, and then vacuum dried to obtain the mixture of alumina and silica. The ratio of alumina and silica to deionized water is 1 g: 0.5–2 mL, the temperature for evaporation is 80–90 °C, and the vacuum drying conditions are: temperature 90–100 °C, time 1–3 h, and vacuum degree 90–95 kPa.

[0017] Furthermore, the mass ratio of the upper stationary phase to the lower stationary phase is 1:5 to 2:1.

[0018] The separation method for separating asphalt hydrocarbon components provided in the third aspect of the present invention includes: firstly, precipitating the asphaltene in the sample with n-heptane; then adding the deasphalted portion to the extraction column described in the second aspect; washing with saturated hydrocarbons to obtain a saturated fraction solution; then washing sequentially with a mixed solvent of saturated hydrocarbons and toluene in different proportions to obtain a light aromatic hydrocarbon solution, a medium aromatic hydrocarbon solution, and a heavy aromatic hydrocarbon solution, respectively; then washing sequentially with a mixed solvent of toluene and alcohols in different proportions to obtain a light gum solution, a medium gum solution, and a heavy gum solution, respectively; finally, rotary evaporating the solvent in the solution and vacuum drying to obtain each component.

[0019] Furthermore, the sample can be at least one of natural asphalt, petroleum asphalt, coal tar pitch, sand and gravel asphalt, and deoiled asphalt, and the mass ratio of the sample to the stationary phase is 1:20 to 50.

[0020] Further, the specific process of precipitating asphalt in the sample with n-heptane is as follows: Dissolve 10g of the asphalt sample in 450-550ml of n-heptane, heat and reflux for 0.8-1.2h, let it stand to settle and filter, wash the precipitate with 45-55ml of n-heptane, and then continue to heat and reflux for 0.8-1.2h with 80-120ml of toluene to obtain an asphalt solution.

[0021] Furthermore, in the step of obtaining saturated fractions after rinsing with saturated hydrocarbons, the saturated hydrocarbons are one or more of petroleum ether, n-pentane, n-hexane, and n-heptane, the ratio of asphalt sample to saturated hydrocarbons is 1g:75-85mL, and the rinsing time is 1-3h.

[0022] Further, in the step of rinsing with a mixed solvent of saturated hydrocarbons and toluene in different ratios to obtain light aromatics, medium aromatics, and heavy aromatics, the saturated hydrocarbons are one or more of petroleum ether, n-pentane, n-hexane, and n-heptane. The volume ratio of the saturated hydrocarbons to toluene is 9–8:1, 1:0.8–1.5, and 1:8–9, respectively, and the ratio of asphalt to the mixed solvent is 1 g: 45–55 mL. The rinsing time is 1–2 h for all steps.

[0023] Further, in the step of rinsing with mixed solvents of toluene and alcohols in different ratios to obtain light, medium, and heavy resins, the alcohols are methanol and / or ethanol. The volume ratios of the toluene and alcohol mixtures are 10:0–0.2, 1:0.8–1.5, and 1:8–9, respectively, and the ratio of asphalt to the mixed solvent is 1 g:45–55 mL. The rinsing time is 1–2 h for all cases.

[0024] Furthermore, the diameter-to-height ratio of the extraction column is 1:75-85.

[0025] Furthermore, the extraction process is carried out under reduced pressure, with a pressure of 0.02–0.05 MPa.

[0026] Furthermore, the extraction temperature is 30–60°C.

[0027] Furthermore, the vacuum drying conditions are: temperature of 105-110℃, time of 1-3h, and vacuum degree of 90-95kPa.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] In existing technologies, silver ions are typically loaded by impregnating silver salt solutions with alumina. This method uses Ag... + The adsorption between Ag and alumina is weak, and Ag is present during elution. + It is easy to detach from the carrier and be lost, which not only contaminates the sample, but also is detrimental to Ag. + The binding with π bonds in the asphalt sample affects the separation efficiency. In contrast, using the stationary phase provided by this invention, the weakly alkaline urea solution causes OH groups to form on the surface of the alumina support. － Under the influence of charge adsorption and ultrasound, Ag + The silver ions are tightly and uniformly adsorbed on the alumina surface, which not only allows for more effective binding with the π bonds in the asphalt sample but also prevents loss during the elution process. The extraction column prepared from this material can accurately and rationally separate the asphalt sample into eight components, among which the aromatic and resinous subcomponents can be separated according to their aromaticity, while improving separation efficiency, effectively avoiding column loss, and preventing silver ions from easily eluting and contaminating the sample. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the extraction device of the present invention;

[0031] Among them, 1 extraction column includes 1-1 upper stationary phase and 1-2 lower stationary phase; 2 flat-bottom flask; 3 vacuum system includes 3-1 vacuum pressure gauge, 3-2 buffer bottle, 3-3 vacuum three-way valve, and 3-4 vacuum pump;

[0032] Figure 2 This is a diagram showing the separation effect of Comparative Example 1, Comparative Example 2 and Example 1. Detailed Implementation

[0033] The present invention will be further described in detail below through embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0034] The following is combined with Figure 1 This invention describes the extraction and separation process. The extraction apparatus of this invention mainly includes an extraction column 1, a flat-bottomed flask 2, and a vacuum system 3. The extraction column 1 includes an upper stationary phase 1-1 and a lower stationary phase 1-2. The vacuum system 3 includes a vacuum pressure gauge 3-1, a buffer bottle 3-2, a vacuum three-way valve 3-3, and a vacuum pump 3-4. The extraction and separation process of this invention includes: first, precipitating the asphaltenes in the sample with n-heptane, and then adding the deasphalted portion to the extraction column 1; washing the extraction column 1 with saturated hydrocarbons, and then the washing liquid enters the flat-bottomed flask 2 to obtain a saturated fractional solution; then washing sequentially with a mixed solvent of saturated hydrocarbons and toluene in different proportions to obtain a light aromatic hydrocarbon solution, a medium aromatic hydrocarbon solution, and a heavy aromatic hydrocarbon solution, respectively; then washing sequentially with a mixed solvent of toluene and alcohols in different proportions to obtain a light colloidal solution, a medium colloidal solution, and a heavy colloidal solution, respectively. Finally, the solvent in the solution is rotary evaporated and vacuum dried to obtain each component.

[0035] Example 1

[0036] This example illustrates the preparation and application process of the stationary phase and extraction column described in this invention.

[0037] Neutral alumina was calcined at 500℃ for 6 hours and then placed in a desiccator for later use. The resulting alumina had a particle size of 100–200 mesh and a specific surface area of ​​300 m². 2 / g. Dissolve 18.90g of silver nitrate in 200ml of deionized water to prepare a silver nitrate solution. Add 200g of activated alumina to the solution and stir until homogeneous. Then add 26.70g of urea and sonicate at 25℃, 200W power, and 40Hz for 30min. Then, dynamically impregnate in a sealed container at 90℃ for 4h with a stirring rate of 600rpm / min. After impregnation, continue stirring with the container open until the solution evaporates to dryness. Then, continue vacuum drying at 150℃ and 93kPa for 4h. Finally, obtain silver-loaded alumina (6% Ag). + Al2O3, placed in a desiccator for later use.

[0038] Take 60g of silica (particle size 100-200 mesh, specific surface area 200m²) 2 / g) and 140g of alumina (particle size 100-200 mesh, specific surface area 300m²) 2 Add 100 ml of deionized water to the mixture (g), stir at 90°C until the solution evaporates to dryness, and then dry under vacuum at 100°C and 93 kPa for 2 hours to obtain a mixture of alumina and silica, which is then placed in a desiccator for later use.

[0039] Take 300g of 6% Ag + Al₂O₃ and a mixture of 100g of alumina and silica were sequentially packed into a glass column, with a diameter-to-height ratio of 1:80. The column was thoroughly mixed by tapping with a thin rubber rod and the stationary phase was moistened with 200ml of n-heptane. The lower end of the stationary phase was connected to a vacuum system.

[0040] Dissolve 10g of 90# petroleum asphalt in 500ml of n-heptane, heat under reflux for 1h, allow to settle and filter, wash the precipitate with 50ml of n-heptane, and continue heating under reflux for 1h with 100ml of toluene to obtain an asphalt solution. The deasphalted asphalt fraction was concentrated and added to the extraction column described above. The extraction temperature was 50℃. First, the fraction was washed with 800 ml of n-heptane to obtain a saturated solution for 2 hours. Then, it was washed with a mixture of 450 ml of n-heptane and 50 ml of toluene to obtain a light aromatic solution for 1 hour. Next, it was washed with a mixture of 250 ml of n-heptane and 250 ml of toluene to obtain a medium aromatic solution for 1 hour. Finally, it was washed with a mixture of 50 ml of n-heptane and 450 ml of toluene to obtain a heavy aromatic solution for 1 hour. A light colloidal solution was then washed with 500 ml of toluene for 1 hour. A medium colloidal solution was then washed with a mixture of 250 ml of toluene and 250 ml of ethanol for 1 hour. A heavy colloidal solution was then washed with a mixture of 50 ml of toluene and 450 ml of ethanol for 1 hour. The vacuum system pressure was adjusted within the range of 0.02–0.05 MPa during the process to control the elution time of each component to 1 hour. Finally, the solvents in each solution were rotary evaporated at 70°C and dried under vacuum at 105°C and 93 kPa for 2 hours to obtain the components. The contents, by mass, were: saturated hydrocarbons (S) 15.6%, light aromatics (LA) 14.4%, medium aromatics (MA) 13.8%, heavy aromatics (HA) 12.4%, light resins (LR) 11.5%, medium resins (MR) 14.1%, heavy resins (HR) 7.4%, and asphaltenes (As) 10.6%, with a total yield of 99.8%.

[0041] The separation effect of asphalt components was measured by proton nuclear magnetic resonance spectroscopy (NMR). 1 The aromatic carbon ratio (f) calculated by H-NMR and elemental analysis (EA) A To conduct the evaluation, f A The higher the value, the more aromatic ring structures the component contains, and the higher the f value of each component. A The greater the difference, the better the separation effect. The calculation formula is as follows:

[0042]

[0043] Among them, C T H represents the total number of carbons. T H represents the total number of hydrogen atoms. α H represents the number of hydrogen atoms on the α-carbon of the substituent attached to the aromatic ring. β H represents the number of hydrogen atoms on the β-carbon of the substituent attached to the aromatic ring. γ This represents the number of hydrogen atoms on the γ-carbon of the substituent attached to the aromatic ring.

[0044] according to 1The results of H-NMR and EA analysis indicate that the f of the saturated fraction A The f of light aromatic hydrocarbons is 0. A The f value of intermediate aromatic hydrocarbons is 0.13. A The f value for heavy aromatics is 0.29. A The value is 0.36, and the f of light gelatin is... A The value is 0.38, and the f value of the medium-colloid is... A The value is 0.44, and the f of heavy gums is... A The f of asphaltene is 0.48. A It is 0.53.

[0045] Example 2

[0046] Neutral alumina was calcined at 500℃ for 6 hours and then placed in a desiccator for later use. The resulting alumina had a particle size of 100–200 mesh and a specific surface area of ​​300 m². 2 / g. Dissolve 6.31g of silver nitrate in 200ml of deionized water to prepare a silver nitrate solution. Add 200g of activated alumina to the solution and stir until homogeneous. Then add 8.92g of urea and sonicate at 25℃, 200W, and 40Hz for 30min. Then, dynamically impregnate the solution in a sealed container at 90℃ for 4h with a stirring rate of 600rpm / min. After impregnation, continue stirring with the container open until the solution evaporates to dryness. Finally, vacuum dry the solution at 150℃ and 93kPa for 4h. The final product is 2% Ag alumina loaded with silver ions. + Al2O3, placed in a desiccator for later use.

[0047] Except for the lower stationary phase prepared in this embodiment, the extraction column preparation and separation process are the same as in Example 1. The final saturated fraction content is 16.8%, the light aromatic hydrocarbon content is 15.1%, the medium aromatic hydrocarbon content is 16.1%, the heavy aromatic hydrocarbon content is 17.4%, the light gum content is 11.5%, the medium gum content is 7.4%, the heavy gum content is 4.1%, the asphaltene content is 10.5%, and the total yield is 98.9%.

[0048] according to 1 The results of H-NMR and EA analysis indicate that the f of the saturated fraction A The f value for light aromatic hydrocarbons is 0.02. A The f of medium aromatic hydrocarbons is 0.17. A The f of heavy aromatics is 0.24. A The value is 0.32, and the f of the light gel is... A The value is 0.4, and the f of the medium-colloid is... A The value is 0.42, and the f of heavy gums is... A The value is 0.43, and the f of asphaltene is... A It is 0.53.

[0049] Example 3

[0050] Neutral alumina was calcined at 500℃ for 6 hours and then placed in a desiccator for later use. The resulting alumina had a particle size of 100–200 mesh and a specific surface area of ​​300 m². 2 / g. Dissolve 31.53g of silver nitrate in 200ml of deionized water to prepare a silver nitrate solution. Add 200g of activated alumina to the solution and stir until homogeneous. Then add 44.5g of urea and sonicate at 25℃, 200W, and 40Hz for 30min. Then, dynamically impregnate the solution in a sealed container at 90℃ for 4h with a stirring rate of 600rpm / min. After impregnation, continue stirring with the container open until the solution evaporates to dryness. Finally, vacuum dry the solution at 150℃ and 93kPa for 4h. The final product is 10% Ag alumina loaded with silver ions. + Al2O3, placed in a desiccator for later use.

[0051] Except for the lower stationary phase prepared in this embodiment, the extraction column preparation and separation process are the same as in Example 1. The final saturated fraction content is 15.1%, the light aromatic hydrocarbon content is 14%, the medium aromatic hydrocarbon content is 13.3%, the heavy aromatic hydrocarbon content is 12.7%, the light gum content is 11.3%, the medium gum content is 15.3%, the heavy gum content is 7.4%, the asphaltene content is 10.6%, and the total yield is 99.7%.

[0052] according to 1 The results of H-NMR and EA analysis indicate that the f of the saturated fraction A The f of light aromatic hydrocarbons is 0. A The f value of the intermediate aromatic hydrocarbon is 0.12. A The f value for heavy aromatics is 0.29. A The value is 0.36, and the f of light gelatin is... A The value is 0.39, and the f value of the medium-colloid is... A The value is 0.44, and the f of heavy gums is... A The value is 0.49, and the f of asphaltene is... A It is 0.53.

[0053] Example 4

[0054] Neutral alumina was calcined at 500℃ for 6 hours and then placed in a desiccator for later use. The resulting alumina had a particle size of 100–200 mesh and a specific surface area of ​​300 m². 2 / g. 18.90g of silver nitrate was dissolved in 200ml of deionized water to prepare a silver nitrate solution. 200g of activated alumina was added to the solution and stirred until homogeneous. Then, 6.68g of urea was added, and the mixture was ultrasonically mixed for 30min at 25℃, 200W power, and 40Hz frequency. The mixture was then dynamically impregnated in a sealed container at 90℃ for 4h with a stirring rate of 600rpm / min. After impregnation, stirring was continued with the container open until the solution evaporated to dryness. Finally, vacuum drying was carried out at 150℃ and 93kPa for 4h. The final product was 6% Ag alumina loaded with silver ions. + / Al2O3-2, store in a desiccator for later use.

[0055] Except for the lower stationary phase prepared in this embodiment, the extraction column preparation and separation process are the same as in Example 1. The final saturated fraction content is 15.8%, the light aromatic hydrocarbon content is 14.7%, the medium aromatic hydrocarbon content is 15.2%, the heavy aromatic hydrocarbon content is 13.2%, the light gum content is 11.6%, the medium gum content is 12.1%, the heavy gum content is 5.8%, the asphaltenes content is 10.6%, and the total yield is 99.0%.

[0056] according to 1 The results of H-NMR and EA analysis indicate that the f of the saturated fraction A The f of light aromatic hydrocarbons is 0.001. A The f of medium aromatic hydrocarbons is 0.14. A The f of heavy aromatics is 0.28. A The value is 0.35, and the f of the light gel is... A The value is 0.39, and the f value of the medium-colloid is... A The value is 0.42, and the f of heavy gums is... A The value is 0.45, and the f of asphaltene is... A It is 0.53.

[0057] Example 5

[0058] The stationary phase and extraction column were prepared according to the method in Example 1, except that the mass ratio of the upper stationary phase to the lower stationary phase was 1:1.

[0059] Take 200g of 6% Ag + Al2O3 and a mixture of 200g of alumina and silica were sequentially packed into a glass column, which was then tapped evenly with a rubber rod and the stationary phase was moistened with 200ml of n-heptane. The lower end was connected to a vacuum system.

[0060] The separation process was the same as in Example 1. The final content of saturated fraction was 16.2%, light aromatics content was 14.9%, medium aromatics content was 16.2%, heavy aromatics content was 17.5%, light gum content was 11.3%, medium gum content was 8.1%, heavy gum content was 4.8%, asphaltene content was 10.7%, and the total yield was 99.7%.

[0061] according to 1 The results of H-NMR and EA analysis indicate that the f of the saturated fraction A The f value for light aromatic hydrocarbons is 0.02. A The f of medium aromatic hydrocarbons is 0.16. A The f value for heavy aromatics is 0.25. A The value is 0.33, and the f of light gelatin is... A The value is 0.41, and the f value of the medium-colloid is... A The f value for heavy aromatics is 0.42. A The value is 0.43, and the f of asphaltene is... A It is 0.53.

[0062] Comparative Example 1

[0063] This example illustrates the separation effect using a conventional alumina column containing 1% water.

[0064] Neutral alumina (same as in Example 1) was calcined at 500°C for 6 hours. After activation, 1% deionized water was added and mixed evenly. 400g of the mixture was weighed and filled into a glass column. The column was then tapped evenly with a rubber rod and the stationary phase was moistened with 200ml of n-heptane. The lower end was connected to a vacuum system.

[0065] Except for the lower stationary phase prepared in this comparative example, the extraction column preparation and separation process were the same as in Example 1. The final saturated fraction content was 17.9%, the light aromatics content was 15.4%, the medium aromatics content was 15.7%, the heavy aromatics content was 17.3%, the light gum content was 9.2%, the medium gum content was 5.8%, the heavy aromatics content was 2.7%, and the asphaltenes content was 10.6%. The total yield was 94.6%, with some column loss.

[0066] according to 1 The results of H-NMR and EA analysis indicate that the f of the saturated fraction A The f value for light aromatic hydrocarbons is 0.05. A The f of medium aromatic hydrocarbons is 0.18. A The f value for heavy aromatics is 0.25. A The value is 0.31, and the f of light gelatin is... A The value is 0.41, and the f value of the medium-colloid is... A The f value for heavy aromatics is 0.42. A The value is 0.43, and the f of asphaltene is... A It is 0.53. For example... Figure 2 There is still component overlap between aromatic components (A) and gums (R), especially in the gum portion, where similar f A This indicates that the components overlap significantly and there is no effective separation.

[0067] Comparative Example 2

[0068] This example illustrates the separation effect of a silver-ion-loaded alumina stationary phase prepared using the conventional impregnation method.

[0069] Neutral alumina (same as in Example 1) was calcined at 500°C for 6 hours and then placed in a desiccator for later use. 18.90 g of silver nitrate was dissolved in 200 ml of deionized water to prepare a silver nitrate solution. 200 g of activated alumina was added to the solution and stirred until homogeneous. The solution was dynamically impregnated at 90°C for 4 hours with a stirring rate of 600 rpm / min. After impregnation, stirring was continued with the solution exposed to the open container until it evaporated to dryness. Subsequently, vacuum drying was carried out at 150°C and 93 kPa for 4 hours. Finally, silver ion-loaded alumina (6% Ag) was obtained. + / Al2O3-3, store in a desiccator for later use.

[0070] Except for the lower stationary phase prepared in this comparative example, the extraction column preparation and separation process were the same as in Example 1. The final saturated fraction content was 15.8%, the light aromatic hydrocarbon content was 14.9%, the medium aromatic hydrocarbon content was 15.5%, the heavy aromatic hydrocarbon content was 13.3%, the light gum content was 11.4%, the medium gum content was 11%, the heavy aromatic hydrocarbon content was 5.9%, the asphaltenes content was 10.7%, and the total yield was 98.5%.

[0071] according to 1 The results of H-NMR and EA analysis indicate that the f of the saturated fraction A The f of light aromatic hydrocarbons is 0.001. A The f of medium aromatic hydrocarbons is 0.14. A The f value for heavy aromatics is 0.29. A The value is 0.35, and the f of the light gel is... A The value is 0.39, and the f value of the medium-colloid is... A The f value for heavy aromatics is 0.42. A The value is 0.45, and the f of asphaltene is... A It is 0.53. For example... Figure 2 Compared with Example 1, there is still some overlap between the aromatic fraction (A) and the gum (R) fractions, especially for the gum fraction, which shows significant differences. This may be due to the loss of silver ions leading to a decrease in selectivity in the later stages.

Claims

1. A method for preparing a stationary phase for separating asphalt hydrocarbon components, characterized in that, The stationary phase is alumina loaded with silver ions. The preparation includes: mixing alumina with a silver salt solution evenly, adding urea and ultrasonically mixing evenly, then sealing and dynamically impregnating for 2-6 hours at an impregnation temperature of 80-90°C, and continuing to stir with the opening open until the solution evaporates to dryness, followed by vacuum drying to obtain the stationary phase. Based on the mass of alumina, the silver content is 1% to 10% by mass; In the method for preparing the stationary phase, the molar ratio of urea to silver is 1:4 to 4:

1. In the method for preparing the stationary phase, the mixing method is ultrasonic mixing, with a power of 100~300W, a frequency of 30~50Hz, a mixing temperature of 20~40℃, and a mixing time of 30~60min; The alumina is neutral alumina with a particle size of 100-200 mesh and a specific surface area of ​​100-300 m². 2 / g; In the method for preparing the stationary phase, the stirring rate of the closed dynamic impregnation is 500~800 rpm / min; the temperature of the vacuum drying is 120~180℃, the vacuum degree is 90~95 kPa, and the drying time is 1~10 h.

2. The preparation method according to claim 1, characterized in that, In the method for preparing the stationary phase, the silver salt is silver nitrate, and the concentration of the silver salt solution is 0.01~0.20 g / mL.

3. An extraction column for separating asphalt hydrocarbon components, comprising an upper stationary phase packed in series and a lower stationary phase prepared by the preparation method according to any one of claims 1-2, wherein the upper stationary phase is a mixture of alumina and silica, wherein the silica content is 20% to 40% by mass.

4. The extraction column according to claim 3, characterized in that, The alumina in the upper stationary phase is neutral alumina with a particle size of 100-200 mesh and a specific surface area of ​​100-300 m². 2 / g; and / or, the silica in the upper stationary phase is selected from silica gel, with a particle size of 100-200 mesh and a specific surface area of ​​200-400 m². 2 / g; and / or, the mass ratio of the upper stationary phase to the lower stationary phase is 1:5 to 2:

1.

5. The extraction column according to claim 3 or 4, characterized in that, The upper stationary phase mixture of alumina and silica was prepared by the following method: alumina, silica, and deionized water were mixed, stirred until the solution was evaporated to dryness, and then vacuum dried to obtain the alumina and silica mixture; wherein, the ratio of alumina and silica to deionized water was 1g:0.5~2mL, the temperature for stirring until the solution was evaporated to dryness was 80~90℃, and the vacuum drying conditions were: temperature 90~100℃, time 1~3h, and vacuum degree 90~95kPa.

6. A method for separating asphalt hydrocarbon components, comprising: firstly precipitating asphaltenes from a sample with n-heptane; then adding the deasphalted portion to an extraction column as described in any one of claims 3 to 5; washing with saturated hydrocarbons to obtain a saturated fraction solution; then washing sequentially with a mixed solvent of saturated hydrocarbons and toluene in different proportions to obtain a light aromatic hydrocarbon solution, a medium aromatic hydrocarbon solution, and a heavy aromatic hydrocarbon solution, respectively; then washing sequentially with a mixed solvent of toluene and alcohols in different proportions to obtain a light gum solution, a medium gum solution, and a heavy gum solution, respectively; and finally, rotary evaporating the solvent in the solution and vacuum drying to obtain each component.

7. The separation method according to claim 6, characterized in that, The sample is at least one of natural asphalt, petroleum asphalt, coal tar pitch, sand and gravel asphalt, and deoiled asphalt, and the mass ratio of the sample to the stationary phase is 1:20~50.

8. The separation method according to claim 6, characterized in that, In the step of obtaining saturated fraction by rinsing with saturated hydrocarbons, the saturated hydrocarbons are one or more of petroleum ether, n-pentane, n-hexane, and n-heptane. The ratio of asphalt sample to saturated hydrocarbons is 1g:75~85mL, and the rinsing time is 1~3h. In the step of rinsing with a mixed solvent of saturated hydrocarbons and toluene in different ratios to obtain light aromatics, medium aromatics, and heavy aromatics, the saturated hydrocarbons are one or more of petroleum ether, n-pentane, n-hexane, and n-heptane; the volume ratio of the saturated hydrocarbons to toluene is 9~8:1, 1:0.8~1.5, and 1:8~9 respectively, the ratio of asphalt to the mixed solvent is 1g:45~55mL, and the rinsing time is 1~2h for all steps. In the step of rinsing with a mixed solvent of toluene and alcohol in different ratios to obtain light, medium, and heavy resins, the alcohols are methanol and / or ethanol, the volume ratios of the toluene and alcohol mixtures are 10:0~0.2, 1:0.8~1.5, and 1:8~9 respectively, the ratio of asphalt to the mixed solvent is 1g:45~55mL, and the rinsing time is 1~2h for all steps.

9. The separation method according to claim 6, characterized in that, The diameter-to-height ratio of the extraction column is 1:75~85.

10. The separation method according to claim 6, characterized in that, The extraction process is carried out under reduced pressure, with a pressure of 0.02~0.05MPa and an extraction temperature of 30~60℃; the vacuum drying conditions are: temperature of 105~110℃, time of 1~3h, and vacuum degree of 90~95kPa.

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