A dechlorination desodium adsorbent, a preparation method and application thereof

Abstract

The application discloses a dechlorination and desodium adsorbent, which comprises an organic metal compound, a molecular sieve and gamma-alumina, and the mass content of the organic metal compound is 2-20% based on the weight of the adsorbent, preferably 3-15%. In the organic metal compound, the content of the metal in the form of an element is 0.3-3.0%, preferably 0.5-2.0%. The dechlorination and desodium adsorbent has a high removal effect on trace amounts of chlorine and sodium in coal-based raw materials.

Description

Technical Field

[0001] This invention belongs to the field of oil refining and relates to a dechlorination and desodiuming adsorbent, its preparation method and application, specifically a dechlorination and desodiuming adsorbent for the simultaneous removal of trace amounts of sodium and chlorine from light oils, its preparation method and application. Background Technology

[0002] Some recycled plastic oils derived from food bags and packaging plastics contain trace amounts of sodium and chlorine. These sodium and chlorine substances can severely affect the processing performance of waste plastic oils: sodium can poison catalysts, while chlorine can corrode equipment. Therefore, developing a simple method for removing sodium and chlorine is of great significance for the pretreatment of waste plastics.

[0003] CN201910271128.4 discloses a dechlorination adsorbent and its preparation method, as well as a method for dechlorinating alkylated oils using composite ionic liquids. The dechlorination adsorbent is prepared by activating a NaY molecular sieve support, then impregnating it with a zinc salt solution using an equal-volume impregnation method, followed by drying and calcination to obtain a zinc-loaded dechlorination adsorbent. This invention provides a new method for the removal and recovery of chlorinated hydrocarbons from alkylated oils using ionic liquids. However, this catalyst cannot absorb Na from the oil, and its effect on removing ionic chlorine is not significant.

[0004] CN201810379910.3 discloses an adsorbent loaded with an alkaline active component, its preparation method, and a method for deep dechlorination. It includes an alkaline active component adsorbent, activated alumina, and the remainder being an alkaline active metal component. The adsorbent loaded with the alkaline active component provided by this invention is applied in the dechlorination process of ionic liquid alkylated oil in a fixed-bed process. The ionic liquid alkylated oil dechlorinated by this process can be directly used as a gasoline blending oil. However, this catalyst cannot absorb Na in the oil, and its removal efficiency for ionic chloride needs further improvement.

[0005] CN202010081626.5 discloses a dechlorination method for waste plastic pyrolysis oil. The method involves reacting the waste plastic pyrolysis oil with hydrogen in the presence of a hydrogenation catalyst. The hydrogenated oil product is then mixed with an adsorbent for adsorption treatment. The adsorbent is a composite of activated alumina and metal element-modified molecular sieves. This dechlorination method has good dechlorination efficiency and is suitable for dechlorinating oils with high chlorine content. However, this method requires high-temperature and high-pressure hydrogenation treatment, and the catalyst is prone to sodium poisoning. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a dechlorination and desodiumation adsorbent, its preparation method, and its application. The dechlorination and desodiumation adsorbent exhibits highly efficient removal of trace amounts of chlorine and sodium from coal-based raw materials.

[0007] The first aspect of the present invention provides a dechlorination and desodiumification adsorbent, the adsorbent comprising organometallic compounds, molecular sieves, and γ-alumina.

[0008] In the adsorbent of this invention, the organometallic compound includes organolithium, organoaluminum, organomagnesium, organozinc, etc., preferably organolithium. In the adsorbent of the present invention, the mass content of the organometallic compound is 2-20%, preferably 3-15%, based on the weight of the adsorbent, and the metal content in the organometallic compound is 0.3-3.0%, preferably 0.5-2.0%, based on the elemental content.

[0009] In the adsorbent of the present invention, the mass content of molecular sieve is 20-70%, preferably 30-60%, based on the weight of the adsorbent.

[0010] In the adsorbent of the present invention, the organic lithium compound includes one or more of lithium organic acid, lithium alcohol (ketone), and alkyl lithium, preferably lithium alcohol (ketone), wherein the lithium alcohol (ketone) includes one or more of lithium isopropoxide, lithium sec-butoxide, lithium tert-butoxide, and lithium acetylacetone.

[0011] In the adsorbent of the present invention, the molecular sieve includes one or more of Y molecular sieve, X molecular sieve, and β molecular sieve, with Y molecular sieve being preferred.

[0012] The silica-to-alumina ratio of the Y-type molecular sieve in the adsorbent of this invention is 5-30, preferably 7-20, and the molecular sieve is an H-type molecular sieve with a Na content of less than 4.0%, preferably less than 2.5%, and a pore volume of 0.2-0.5 cm³. 3 / g, preferably 0.25-0.45 cm 3 / g, specific surface area is 500-900 m² 2 / g, preferably 600-800 m 2 / g.

[0013] In the adsorbent of the present invention, the alumina content is 15-45% by weight, preferably 20%-40%.

[0014] In the adsorbent of this invention, the pore volume of the γ-alumina is 0.6-1.1 cm³. 3 / g, preferably 0.7-1.0 cm 3 / g, specific surface area is 200-400 m² 2 / g, preferably 250-350 m 2 / g.

[0015] A second aspect of the present invention provides a method for preparing a sodium- and chloride-removing adsorbent, the method comprising the following steps: Step 1: Prepare or select an alumina and molecular sieve composite support; Step 2: Prepare an impregnation solution containing organometallic salts; Step 3: Impregnate the carrier obtained in Step 1 with the impregnation solution obtained in Step 2, and obtain the final sodium and chloride removal adsorbent after vacuum drying.

[0016] In step one of the method of this invention, the composite carrier of alumina and molecular sieve can be prepared according to existing technologies. For example, alumina and molecular sieve can be mixed and kneaded together.

[0017] In step two of the method of the present invention, the concentration of the organometallic salt is 0.5-10 mol / L, preferably 1.0-8.0 mol / L, and the solvent is one or more of ethanol, acetone, 2-propanol, 1-propanol, and n-butanol.

[0018] In step three of the method of the present invention, the soaking is followed by standing for 4-24 hours, preferably 6-18 hours.

[0019] In step three of the method of the present invention, the temperature of vacuum drying is 50-120°C, preferably 60-100°C, the drying time is 2-12 hours, preferably 3-10 hours, and the vacuum degree during drying is 0.1-5.0 torr, preferably 0.5-2.0 torr.

[0020] A third aspect of the present invention provides a dechlorination and desodiumification method, wherein the method uses the above-mentioned adsorbent, and the oil is subjected to dechlorination and desodiumification treatment under the action of the adsorbent.

[0021] In the above method, the oil contains trace amounts of sodium and chlorine impurities, with the sodium content in the sample being ≤15 ppm, preferably 5-10 ppm, and the chlorine content being ≤10.0 ppm, preferably 1-5.0 ppm.

[0022] In the above method, the adsorption conditions are as follows: temperature 20-90°C, preferably 40-80°C; reaction pressure 0.1-1.0 MPa, preferably 0.2-0.8 MPa; and liquid hourly space velocity 0.2-2.0 h⁻¹. -1 Preferably 0.3-1.0 h -1 .

[0023] Researchers studying the dechlorination and desodiumation of oil products discovered that trace amounts of chlorinated species in waste plastic oil can undergo a displacement reaction with organometallic compounds (preferably organolithium) at certain temperatures, generating lithium chloride and corresponding organic compounds. Simultaneously, molecular sieves adsorb trace amounts of sodium ions from the oil. The synergistic effect between organolithium and molecular sieves reduces sodium and chlorine levels in the oil while maintaining the system's charge balance. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments, but it should be understood that the scope of protection of the present invention is not limited to the embodiments. In the present invention, unless otherwise expressly stated, percentages and contents are all expressed by mass.

[0025] The Y-type molecular sieve used in this experiment was industrial HY molecular sieve, with a specific surface area of ​​690 m². 2 / g, pore volume 0.37 cm³ 3 / g, with a silicon-to-aluminum ratio of 7.3:1 and a sodium content of 2.6%.

[0026] Weigh out 500.0 g of aluminum hydroxide dry adhesive powder, 500.0 g of HY molecular sieve, 700.0 g of deionized water, 30.0 g of nitric acid, and 50.0 g of citric acid. After kneading for 10 min and rolling for 20 min, the mixture is extruded into strips using a cylindrical perforated plate with a diameter of 1.5 mm. After drying at 120°C for 4.0 h and calcining at 550°C for 4.0 h, the resulting carrier is denoted as S-0. Example 1

[0027] Weigh 10.0 g of lithium isopropoxide and 40.0 g of 2-propanol, and the resulting solution is denoted as LQ-1.

[0028] Weigh 100.0 g of S-0, impregnate S-0 with LQ-1, let it stand for 8.0 hours, and then dry it in a vacuum drying oven for 6.0 hours. The drying conditions are: vacuum degree of 1.0 tor and drying temperature of 80℃. The resulting adsorbent material is denoted as M-1. Example 2

[0029] Weigh 12.0 g of lithium sec-butoxide and 40.0 g of n-butanol, and the resulting solution is denoted as LQ-2.

[0030] Weigh 100.0 g of S-0, impregnate S-0 with LQ-2, let it stand for 8.0 hours, and then dry it in a vacuum drying oven for 6.0 hours. The drying conditions are: vacuum degree of 1.0 tor and drying temperature of 80℃. The resulting adsorbent material is denoted as M-2. Example 3

[0031] Weigh 12.0 g of lithium tert-butoxide and 40.0 g of n-butanol, and the resulting solution is denoted as LQ-3.

[0032] Weigh 100.0 g of S-0, impregnate S-0 with LQ-3, let it stand for 8.0 hours, and then dry it in a vacuum drying oven for 6.0 hours. The drying conditions are: vacuum degree of 1.0 tor and drying temperature of 80℃. The resulting adsorbent material is denoted as M-3. Example 4

[0033] Weigh 13.0 g of lithium acetylacetonate and 40.0 g of n-butanol, and the resulting solution is denoted as LQ-4.

[0034] Weigh 100.0 g of S-0, impregnate S-0 with LQ-4, let it stand for 8.0 hours, and then dry it in a vacuum drying oven for 6.0 hours. The drying conditions are: vacuum degree of 1.0 tor and drying temperature of 80℃. The resulting adsorbent material is denoted as M-4. Example 5

[0035] Weigh out 15.0 g of aluminum isopropoxide and 40.0 g of n-butanol, and the resulting solution is denoted as LQ-4.

[0036] Weigh 100.0 g of S-0, impregnate S-0 with LQ-4, let it stand for 8.0 hours, and then dry it in a vacuum drying oven for 6.0 hours. The drying conditions are: vacuum degree of 1.0 tor and drying temperature of 80℃. The resulting adsorbent material is denoted as M-5. Example 6

[0037] Weigh out 15.0 g of magnesium isopropoxide and 40.0 g of n-butanol, and the resulting solution is denoted as LQ-4.

[0038] Weigh 100.0 g of S-0, impregnate S-0 with LQ-4, let it stand for 8.0 hours, and then dry it in a vacuum drying oven for 6.0 hours. The drying conditions are: vacuum degree of 1.0 tor and drying temperature of 80°C. The resulting adsorbent material is denoted as M-6.

[0039] Comparative Example 1 S-0 is used as the adsorbent material and is designated as DM-1.

[0040] Comparative Example 2 Weigh 800.0 g of aluminum hydroxide dry adhesive powder, 700.0 g of deionized water, 30.0 g of nitric acid, and 50.0 g of citric acid. After kneading for 10 min and rolling for 20 min, the mixture is extruded into strips using a cylindrical perforated plate with a diameter of 1.5 mm. The resulting carrier is denoted as DS-2.

[0041] The preparation process of solution LQ-1 is the same as in Example 1.

[0042] Weigh 100.0 g of DS-2, impregnate S-0 with LQ-1, let stand for 8.0 hours, and then dry in a vacuum drying oven for 6.0 hours. The drying conditions are: vacuum degree of 1.0 tor and drying temperature of 80°C. The resulting adsorbent material is denoted as DM-2.

[0043] Comparative Example 3 Weigh 5.0 g of lithium nitrate and 50.0 g of deionized water, and the resulting solution is denoted as DQ-3.

[0044] Weigh 100.0 g of S-0, impregnate S-0 with DQ-3, let it stand for 8.0 hours, and then dry it in a vacuum drying oven for 6.0 hours. The drying conditions are: vacuum degree of 1.0 tor and drying temperature of 100℃. The resulting adsorbent material is denoted as DM-3.

[0045] The Li content, Si / Al ratio, and carbon content of the adsorbent material were analyzed, and the results are shown in Table 1. Table 1 Content of key components of adsorbent Adsorbent material number Organometallic additive content (wt%) Metallic element types Metallic elements wt% Molecular sieve content (wt%) M-1 9.1 Li 0.97 58.1 M-2 10.7 Li 0.93 57.2 M-3 10.7 Li 0.92 57.1 M-4 11.5 Li 0.76 56.6 M-5 13.0 Al 1.50 55.1 M-6 12.9 Mg 1.91 55.6 DM-1 - - - 63.7 DM-2 9.1 Li 0.96 58.0 DM-3 9.2 Li 0.92 58.1 Examples 7-12 Waste plastic oil was used as raw material to evaluate the adsorbents obtained in Examples 1-4 above. The sodium and chlorine contents in the raw material are shown in Table 3. The evaluation conditions were: reaction temperature 60℃, reaction pressure 0.5 MPa, and liquid hourly space velocity 0.5 h⁻¹. -1 After 400 hours of treatment, the extracted samples were analyzed for sodium and chlorine, and the results are shown in Table 2.

[0046] Comparative Examples 4-6 Waste plastic oil was used as raw material to evaluate the adsorbents obtained in Comparative Examples 1-3. The sodium and chlorine contents of the raw material are shown in Table 3. The evaluation conditions were: reaction temperature 60℃, reaction pressure 0.5 MPa, and liquid hourly space velocity 0.5 h⁻¹. -1 After 400 hours of treatment, the extracted samples were analyzed for sodium and chlorine, and the results are shown in Table 3.

[0047] Table 2. Adsorbent Evaluation Results Sample number Adsorbent Sodium content (μg / g) Chlorine content (μg / g) raw material - 4.8 9.4 Example 7 M-1 0.4 0.2 Example 8 M-2 0.2 0.3 Example 9 M-3 0.3 0.2 Example 10 M-4 0.4 0.4 Example 11 M-5 1.1 3.4 Example 12 M-6 0.9 3.2 Comparative Example 4 DM-1 2.8 8.9 Comparative Example 5 DM-2 4.0 4.6 Comparative Example 6 DM-3 2.5 7.8 The evaluation results show that the bifunctional sodium chloride dechlorination catalyst prepared by this method has strong sodium and chloride removal capabilities and good long-term stability.

Claims

1. A dechlorination and desodiumning adsorbent, characterized in that: the adsorbent comprises organometallic compounds, molecular sieves, and γ-alumina.

2. The adsorbent according to claim 1, characterized in that: The organometallic compound includes one or more of organolithium, organoaluminum, organomagnesium, and organozinc, with organolithium being preferred.

3. The adsorbent according to claim 1, characterized in that: Based on the weight of the adsorbent, the mass content of the organometallic compound is 2-20%, preferably 3-15%, and the metal content in the organometallic compound is 0.3-3.0%, preferably 0.5-2.0%, calculated as elemental metal.

4. The adsorbent according to claim 1, characterized in that: Based on the weight of the adsorbent, the mass content of molecular sieve is 20-70%, preferably 30-60%.

5. The adsorbent according to claim 2, characterized in that: Organolithium compounds include one or more of lithium organic acids, lithium alcohols (ketones), and alkyl lithiums, with lithium alcohols (ketones) being preferred.

6. The adsorbent according to claim 5, characterized in that: The lithium alcohol (ketone) includes one or more of lithium isopropoxide, lithium sec-butoxide, lithium tert-butoxide, and lithium acetylacetone.

7. The adsorbent according to claim 1, characterized in that: The molecular sieve includes one or more of Y molecular sieve, X molecular sieve, and β molecular sieve, with Y molecular sieve being preferred.

8. The adsorbent according to claim 7, characterized in that: The Y-type molecular sieve has a silica-to-alumina ratio of 5-30, preferably 7-20, a Na content of less than 4.0 wt%, preferably less than 2.5 wt%, and a pore volume of 0.2-0.5 cm³. 3 / g, preferably 0.25-0.45 cm 3 / g, specific surface area is 500-900 m² 2 / g, preferably 600-800 m 2 / g.

9. The adsorbent according to claim 1, characterized in that: Based on the weight of the adsorbent, the alumina content is 15-45%, preferably 20%-40%.

10. The adsorbent according to claim 1, characterized in that: The γ-alumina has a pore volume of 0.6-1.1 cm³. 3 / g, preferably 0.7-1.0 cm 3 / g, specific surface area is 200-400 m² 2 / g, preferably 250-350 m 2 / g.

11. A method for preparing any one of the sodium- and chloride-removing adsorbents according to claims 1-10, the method comprising the following steps: Step 1: Prepare or select a composite support of alumina and molecular sieve; Step 2: Prepare an impregnation solution containing organometallic salts; Step 3: Impregnate the carrier obtained in Step 1 with the impregnation solution obtained in Step 2, and then dry it under vacuum to obtain the final sodium and chlorine removal adsorbent.

12. The method according to claim 11, characterized in that: In step one, the alumina and molecular sieve composite carrier is prepared according to existing technology, preferably by mixing and molding alumina and molecular sieve.

13. The method according to claim 11, characterized in that: In step two, the concentration of the organometallic salt is 0.5-10 mol / L, preferably 1.0-8.0 mol / L, and the solvent is one or more of ethanol, acetone, 2-propanol, 1-propanol, and n-butanol.

14. The method according to claim 11, characterized in that: After soaking in step three, let it stand for 4-24 hours, preferably 6-18 hours.

15. The method according to claim 11, characterized in that: The vacuum drying temperature in step three is 50-120°C, preferably 60-100°C, the drying time is 2-12 hours, preferably 3-10 hours, and the vacuum degree during drying is 0.1-5.0 torr, preferably 0.5-2.0 torr.

16. A method for dechlorination and desodiumification, characterized in that: The method uses the adsorbent according to claims 1-10, and the oil is dechlorinated and desodiumed under the action of the adsorbent.

17. The method according to claim 16, characterized in that: The oil contains trace amounts of sodium and chlorine impurities. The sodium content in the sample is ≤15 ppm, preferably 5-10 ppm, and the chlorine content is ≤10.0 ppm, preferably 1-5.0 ppm.

18. The method according to claim 11, characterized in that: The adsorption conditions are as follows: temperature 20-90°C, preferably 40-80°C; reaction pressure 0.1-1.0 MPa, preferably 0.2-0.8 MPa; and liquid hourly space velocity 0.2-2.0 h⁻¹. -1 Preferably 0.3-1.0h -1 .