Preparation method of adsorbent for waste fan oil regeneration, adsorbent and regeneration method

Abstract

The invention discloses a preparation method of an adsorbent for regeneration of waste fan oil, the adsorbent and a regeneration method. The preparation method comprises the following steps: (1) preparing materials: mixing an alkali source, a silicon source, an aluminum source, organic amine and water to obtain a mixture; (2) crystallization: putting the mixture obtained in the step (1) into a crystallization kettle for hydrothermal crystallization, and after the crystallization is completed, separating and drying to obtain a crystallized material; (3) slurry preparation: mixing the crystallized material obtained in the step (2), natural silicon-aluminum minerals, an adhesive and water into slurry; (4) spray drying: performing spray drying on the slurry obtained in the step (3) to obtain powder; and (5) roasting: roasting the powder obtained in the step (4) to obtain the adsorbent. The mesoporous-macroporous silicon-aluminum material is synthesized by adopting a crystallization-spraying method, and compared with a common adsorbent, the mesoporous-macroporous silicon-aluminum material is beneficial to reducing the mass transfer resistance of macromolecular wind driven generator gear lubricating oil in the adsorbent, meanwhile, the adsorption effect on polar substances is remarkable, the oleic acid value of a waste fan can be greatly reduced, and residual additives can be removed.

Description

Technical Field

[0001] The invention relates to the field of lubricating oil regeneration, and in particular to a preparation method of an adsorbent for waste fan oil regeneration, the adsorbent and a regeneration method. Background Art

[0002] As one of the main forms of renewable energy power generation, wind power has seen its installed capacity continue to rise in recent years. As of June 30, 2022, the total installed capacity of wind power connected to the grid in China has exceeded 342 million kilowatts. As the core equipment of wind power generation, wind turbines are composed of rotor blades, shafts, gearboxes, generators and other components. Wind power lubricants, especially main gear oils, are the "blood" of wind turbines and play a vital role in reducing friction of rotating parts and ensuring the normal operation of the units.

[0003] It is estimated that the current global consumption of wind turbine gear oil is between 20,000 and 40,000 tons, half of which comes from China. Considering the development trend of my country's energy transformation, the demand for domestic wind turbine lubricants will continue to grow rapidly in the future. Therefore, a large amount of waste wind turbine gear oil is generated in China every year. If it can be recycled, it will greatly reduce the hazardous waste emissions of wind power companies and save a large amount of operation and maintenance investment. Compared with waste automotive oil, although waste fan oil has a lower degree of deterioration, it has a high viscosity, a heavy distillation range, and there are differences in deteriorated components and additives. Therefore, the regeneration process applicable to automotive waste oil is not applicable to waste fan oil.

[0004] At present, the treatment process for automotive waste oil is mainly physical adsorption, which mainly includes two process routes: acid clay and acid-free clay. Both use activated clay as the adsorbent. It is low-cost and has good treatment effect, but its problems are also prominent, which are manifested in high treatment temperature, serious equipment corrosion (acid-free clay process) or great damage to the environment (acid clay process). In addition, after experiments, the author found that clay has a very poor treatment effect on high-viscosity, high-molecular-weight, and highly polar additive-containing fan waste oil, and it can basically not be used.

[0005] CN201410085216.2 utilizes catalytic cracking resurrection catalyst and artificially synthesized silicon-aluminum composite carrier to prepare microspherical solid adsorbent, which can effectively adsorb and remove polar molecular colloids produced by hydrolysis of waste lubricating oil, reduce the acid value of oil, and remove sludge and oil color.

[0006] CN201711148687.3 discloses an adsorbent for regenerating mineral waste engine oil, including modified zeolite powder, modified mesoporous silica and magnesium trisilicate, which needs to be used in combination with organic bentonite and activated carbon.

[0007] CN201710570477.7 discloses a method for regenerating waste lubricating oil containing glue, which comprises heating the waste lubricating oil to a certain degree, adding an adsorbent, and stirring so that the adsorbent can fully adsorb and polymerize the glue components in the waste lubricating oil, so that the glue is completely formed into a solid state, and obtaining No. 320 wind power regenerated oil by strong magnetic precipitation and filtration.

[0008] In general, the existing physical regeneration schemes for fan oil mostly draw on traditional waste oil treatment methods, and the adsorbents used are mostly minerals such as white clay. Due to the large molecular weight of fan oil and unique additives, the treatment effect is limited, the quality of the regenerated oil is not high, and the lifespan is not long. Summary of the invention

[0009] In view of this, the object of the present invention is to provide a method for preparing an adsorbent for waste fan oil regeneration, an adsorbent and a regeneration method, so as to facilitate high-quality regeneration of fan lubricating oil.

[0010] To achieve one aspect of the above-mentioned invention object, the present invention adopts the following technical solution:

[0011] A method for preparing an adsorbent for waste fan oil regeneration, the preparation method comprising the following steps:

[0012] (1) Ingredients: an alkali source, a silicon source, an aluminum source, an organic amine and water are mixed to obtain a mixture, wherein the molar ratio of alkali: silicon element: aluminum element: organic ammonium: water is (0.1-2):1:(0.02-0.4):(0.05-1.2):(5-100);

[0013] (2) Crystallization: placing the mixed material obtained in step (1) into a crystallization kettle for hydrothermal crystallization, and after the crystallization is completed, separating and drying to obtain a crystallized material;

[0014] (3) Slurry preparation: the crystallized material obtained in step (2), natural silica-aluminum mineral, adhesive and water are mixed into a slurry; wherein, by weight, the amount of the crystallized material is 20-60 parts, the amount of the natural silica-aluminum mineral is 10-80 parts, the amount of the adhesive is 10-100 parts, and the amount of water is 50-300 parts;

[0015] (4) spray drying: spray drying the slurry obtained in step (3) to obtain a powder;

[0016] (5) Calcination: Calcinate the powder obtained in step (4) to obtain an adsorbent.

[0017] In step (1) of the present invention, the silicon source may be a silicon source commonly used in the hydrothermal crystallization synthesis of silicon-aluminum materials; in one embodiment, the silicon source may be one or more of water glass, silica sol, tetraethyl orthosilicate (TEOS), and white carbon black.

[0018] In step (1) of the present invention, the aluminum source may be an aluminum source commonly used in the hydrothermal crystallization synthesis of silicon-aluminum materials; in one embodiment, the aluminum source may be one or more of sodium aluminate, pseudo-boehmite, and γ-alumina.

[0019] In step (1) of the present invention, the organic amine may be a template commonly used in the hydrothermal crystallization synthesis of silicon-aluminum materials; in one embodiment, the organic amine may be one or more of hexadecyltrimethylammonium bromide (CTAB), hexadecyltrimethylammonium hydroxide (CTAOH), and tetramethylammonium hydroxide (TMAOH).

[0020] In step (1) of the present invention, the alkali source may be an alkali source commonly used in the hydrothermal crystallization synthesis of silicon-aluminum materials; in one embodiment, the alkali source may be one or more of NaOH and KOH.

[0021] In some embodiments, when preparing the ingredients in step (1), the organic amine and water are stirred and mixed, and then the silicon source, aluminum source and alkali source are added and stirred and mixed. Preferably, before the crystallization in step (2), the pH of the mixture is adjusted to 10-14, such as 11, 12 or 13, for example, by adjusting with hydrochloric acid, nitric acid or sulfuric acid when necessary.

[0022] In step (1) of the present invention, the molar ratio of base: silicon: aluminum: organic ammonium: water is (0.1-2): 1: (0.02-0.4): (0.05-1.2): (5-100). For example, based on 1 mol of silicon, the amount of base can be 0.3, 0.6, 0.8, 1.2 or 1.5 mol, the amount of aluminum can be 0.05, 0.1, 0.2 or 0.3 mol, the amount of organic amine can be 0.08, 0.12, 0.16, 0.2, 0.5 or 0.8 mol, and the amount of water can be 15, 25, 50 or 80 mol. Preferably, in step (1), the molar ratio of base: silicon: aluminum: organic ammonium: water is (0.2-1): 1: (0.04-0.25): (0.1-1.0): (10-80).

[0023] In step (2) of the present invention, the obtained mixture is placed in a crystallization kettle for hydrothermal crystallization. The hydrothermal crystallization reaction is well known in the art. In some embodiments, in step (2), the crystallization temperature is 100-200°C, such as 120, 150 or 180°C, and the crystallization time is 1-10 days, such as 2, 5 or 8 days. It is understood in the art that too short a time may make it difficult to achieve sufficient crystallization, while too long a time may easily lead to low efficiency.

[0024] In step (3) of the present invention, in the prepared slurry, the amount of crystallization material is 20-90 parts, such as 30, 50, 60 or 70 parts, the amount of natural silica-aluminum mineral is 10-80 parts, such as 30, 40, 50 or 70 parts, the amount of adhesive is 5-20 parts, such as 10 parts, and the amount of water is 100-300 parts, such as 150, 200 or 280 parts, which are mixed into a slurry; preferably, the amount of crystallization material is 40-80 parts, the amount of natural silica-aluminum mineral is 20-60 parts, the amount of adhesive is 8-15 parts, and the amount of water is 120-250 parts.

[0025] In the present invention, the natural silica-aluminum mineral may include one or more of activated clay, attapulgite, halloysite, montmorillonite, illite, diatomaceous earth, bentonite and the like.

[0026] In the present invention, the adhesive may include one or both of aluminum sol and silica sol. In some embodiments, the solid content of silicon dioxide is 15-40wt%, such as 18wt%, 20wt%, 25wt% or 30wt%, and the aluminum oxide content of the aluminum sol is 10%-30wt%, such as 15wt%, 20wt% or 25wt%.

[0027] In step (4) of the present invention, the slurry obtained in step (3) is spray-dried to obtain a powder, i.e., an adsorbent precursor. Preferably, in step (4), the spray-drying temperature is 150-400°C, such as 200, 250 or 300°C.

[0028] In a preferred embodiment, before the spray drying in step (4), the slurry is aged for 1-5 hours, so that the components of the adsorbent can be fully contacted and mixed, thereby increasing the molding strength and the adsorption effect on the polar components in the waste oil.

[0029] In step (5) of the present invention, the powder obtained by spray drying is calcined, and the calcination temperature can be 400-650°C, preferably the calcination temperature is 450-600°C, such as 500 or 550°C.

[0030] In order to achieve another aspect of the above-mentioned object of the invention, the present invention also provides an adsorbent prepared by the above-mentioned preparation method; in some embodiments, the pore volume thereof is 0.4-1.5 cm 3 / g such as 0.5, 0.8, 1.0, 1.1 or 1.2 cm 3 / g, specific surface area is 400-1500m 2 / g such as 500, 700, 800, 900, 1200 or 1300m 2 / g.

[0031] To achieve another aspect of the above-mentioned object of the invention, the present invention also provides a method for regenerating waste fan oil, wherein the regeneration method comprises mixing the adsorbent with the waste fan oil, stirring and adsorbing the mixture, and then filtering the mixture to obtain the regenerated fan oil.

[0032] In a preferred embodiment, the adsorbent is used in an amount of 3-20 wt % of the waste fan oil, such as 5, 8, 10, 12, 15 or 18 wt %;

[0033] Preferably, when stirring adsorption is performed, the stirring temperature is 50-250° C., such as 80, 100, 150 or 200° C., and the adsorption time is 1-12 h, such as 2, 4, 6, 8 or 10 h.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] (1) The present invention adopts a crystallization-spraying method to synthesize meso-macroporous silicon-alumina materials, and the synthesized molecular sieve-like crystallized product is compounded with natural silicon-alumina minerals, and the two are spray-dried and calcined to make the two cooperate with each other to achieve a better adsorption effect of the product, especially for phosphorus and iron in waste oil;

[0036] (2) Compared with common adsorbents, this material is beneficial to reducing the mass transfer resistance of large-molecule wind turbine gear lubricating oil in the adsorbent. At the same time, it has a significant adsorption effect on polar substances, which can greatly reduce the acid value of waste wind turbine oil and remove residual additives.

[0037] (3) It can be used alone as a physical adsorption adsorbent, and can also be used for adsorption pretreatment of raw materials in the hydrogenation regeneration route. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with the embodiments, but the present invention is not limited to the listed embodiments, but also includes equivalent improvements and modifications of the technical solutions defined in the claims attached to the patent application of the present invention.

[0039] 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, such as values ​​of ±10% of the endpoint values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0040] Unless otherwise specified, all relevant reagents in the following examples / comparative examples are of analytical grade.

[0041] Example 1

[0042] Take 32.8g CTAB and mix it evenly with 280.0g water, add 10.8g NaOH, 150.0g silica sol (silicon dioxide content 30wt%, the same below) and 3.1g sodium aluminate while stirring, adjust the pH to 12.0 with hydrochloric acid, stir evenly and put it into a crystallization kettle, crystallize at 110℃ for 48h, cool to room temperature and filter and dry. Take 40g of this product, mix it evenly with 10g activated clay and 30g aluminum sol (alumina content 20wt%, the same below), 150g water and age it for 2h, put it into a spray tower, control the temperature at 400℃, and heat the obtained powder to 600℃ at a heating rate of 2℃ / min, and roast it for 3h to obtain the adsorbent. After testing, its pore volume is 1.1cm 3 / g, specific surface area is 1269m 2 / g.

[0043] The adsorbent was mixed with waste fan oil at a weight ratio of 1:20, and stirred at 80°C for 2 hours. The product was filtered and analyzed. See Table 1 below for details.

[0044] Example 2

[0045] Take 54.6g TMAOH and mix it evenly with 280.0g water, add 18.9g NaOH, 150.0g silica sol and 12.3g sodium aluminate while stirring, adjust the pH to 12.0 with hydrochloric acid, stir evenly and put it into a crystallization kettle, crystallize it at 180℃ for 144h, cool it to room temperature and filter and dry it. Take 20g of this product, mix it evenly with 30g attapulgite and 36g aluminum sol, 120g water and age it for 5h, put it into a spray tower, control the temperature at 200℃, and heat the obtained powder to 400℃ at a heating rate of 2℃ / min, and roast it for 8h to obtain the adsorbent. After testing, its pore volume is 0.7cm 3 / g, specific surface area is 812m 2 / g.

[0046] The adsorbent was mixed with waste fan oil in a weight ratio of 1:5, and stirred at 150°C for 6 hours. The product was filtered and analyzed. The details are shown in Table 1 below.

[0047] Example 3

[0048] Take 43.6g CTAB and mix it evenly with 280.0g water, add 15.8g NaOH, 150.0g silica sol and 6.3g sodium aluminate while stirring, adjust the pH to 12.0 with hydrochloric acid, stir evenly and put it into the crystallization kettle, crystallize it at 150℃ for 72h, cool it to room temperature and filter and dry it. Take 35g of this product, mix it evenly with 35g diatomaceous earth, 14g aluminum sol and 140g water and age it for 3h, put it into the spray tower, control the temperature at 350℃, and heat the obtained powder to 500℃ at a heating rate of 2℃ / min, and roast it for 6h to obtain the adsorbent. After testing, its pore volume is 0.8cm 3 / g, specific surface area is 907m 2 / g.

[0049] The adsorbent was mixed with waste fan oil in a weight ratio of 1:10, and stirred at 120°C for 4 hours. The product was filtered and analyzed. See Table 1 below for details.

[0050] Example 4

[0051] Take 54.6g CTAB and mix it evenly with 280.0g water, add 10.8g NaOH, 150.0g silica sol and 3.1g sodium aluminate while stirring, adjust the pH to 12.0 with hydrochloric acid, stir evenly and put it into a crystallization kettle, crystallize it at 100℃ for 24h, cool it to room temperature and filter and dry it. Take 20g of this product, mix it evenly with 80g montmorillonite soil, 100g silica sol and 50g water and age it for 1h, put it into a spray tower, control the temperature at 380℃, and heat the obtained powder to 650℃ at a heating rate of 2℃ / min, and roast it for 3h to obtain the adsorbent. After testing, its pore volume is 0.6cm 3 / g, specific surface area is 693m 2 / g.

[0052] The adsorbent was mixed with waste fan oil in a weight ratio of 1:10, and stirred at 90°C for 12 hours. The product was filtered and analyzed. See Table 1 below for details.

[0053] Comparative Example 1

[0054] Compared with claim 1, the difference is that the dried crystallized material is directly calcined to obtain the adsorbent.

[0055] The other is the same as Example 1. After testing, the pore volume is 1.0cm 3 / g, specific surface area is 1180m 2 / g.

[0056] Comparative Example 2

[0057] Take 50g of activated clay and 30g of aluminum sol (alumina content 20%), mix well with 150g of water and age for 2h, then put into a spray tower with the same control conditions as in Example 1. The obtained powder is heated to 600°C at a heating rate of 2°C / min and calcined for 3h to obtain contrast agent 2.

[0058] The rest is the same as in Example 1. After testing, the pore volume is 0.2 cm 3 / g, specific surface area is 183m 2 / g.

[0059]

[0060] It can be seen from the above that the waste fan oil treated with the adsorbent of the present invention has significantly improved appearance and significantly reduced acid value, and can completely remove the wear iron elements and residual phosphorus-containing additives in the waste oil; compared with Comparative Example 1, even when the pore volume and / or specific surface area are basically the same or significantly smaller, the adsorption effect is also significantly excellent, which is unexpected in the art.

Claims

1. A method for preparing an adsorbent for waste fan oil regeneration, characterized in that: The preparation method comprises the following steps: (1) Ingredients: an alkali source, a silicon source, an aluminum source, an organic amine and water are mixed to obtain a mixture, wherein the molar ratio of alkali: silicon element: aluminum element: organic ammonium: water is (0.1-2):1:(0.02-0.4):(0.05-1.2):(5-100); (2) Crystallization: placing the mixed material obtained in step (1) into a crystallization kettle for hydrothermal crystallization, and after the crystallization is completed, separating and drying to obtain a crystallized material; (3) Slurry preparation: the crystallized material obtained in step (2), natural silica-aluminum mineral, adhesive and water are mixed into a slurry; wherein, by weight, the amount of the crystallized material is 20-60 parts, the amount of the natural silica-aluminum mineral is 10-80 parts, the amount of the adhesive is 10-100 parts, and the amount of water is 50-300 parts; (4) spray drying: spray drying the slurry obtained in step (3) to obtain a powder; (5) Calcination: Calcinate the powder obtained in step (4) to obtain an adsorbent.

2. The preparation method according to claim 1, characterized in that: In step (1), the silicon source may be one or more of water glass, silica sol, tetraethyl orthosilicate (TEOS), and white carbon black; the aluminum source may be one or more of sodium aluminate, pseudo-boehmite, and γ-alumina; the organic amine may be one or more of cetyltrimethylammonium bromide (CTAB), cetyltrimethylammonium hydroxide (CTAOH), and tetramethylammonium hydroxide (TMAOH); and the alkali source may be one or more of NaOH and KOH.

3. The preparation method according to claim 1, characterized in that: Before the crystallization in step (2), the pH of the mixture is adjusted to 10-14.

4. The preparation method according to claim 1, characterized in that: In step (1), the molar ratio of base: silicon element: aluminum element: organic ammonium: water is (0.2-1):1: (0.04-0.25): (0.1-1.0): (10-80).

5. The preparation method according to claim 1, characterized in that: In step (3), when preparing the slurry, the amount of the crystallization material is 20-60 parts, the amount of natural silica-aluminum mineral is 10-50 parts, the amount of adhesive is 30-70 parts, and the amount of water is 80-250 parts.

6. The preparation method according to any one of claims 1 to 5, characterized in that: In step (3), the natural silica-aluminum mineral is one or more of activated clay, attapulgite, halloysite, montmorillonite, illite, diatomaceous earth and bentonite; The adhesive is one or both of aluminum sol and silica sol.

7. The preparation method according to claim 1, characterized in that: Before spray drying in step (4), the slurry is aged for 1-5 hours.

8. The preparation method according to claim 1, characterized in that: In step (2), the crystallization temperature is 100-200° C. and the crystallization time is 1-10 days; In step (4), the spray drying temperature is 150-400°C; In step (5), the calcination temperature is 400-650°C.

9. An adsorbent prepared by the preparation method according to any one of claims 1 to 8.

10. A method for regenerating waste fan oil, characterized in that: Mixing the adsorbent according to claim 9 with waste fan oil, stirring and adsorbing, and then filtering to obtain regenerated fan oil; Preferably, the adsorbent is used in an amount of 3-20 wt % of the waste fan oil; Preferably, when stirring adsorption is performed, the stirring temperature is 50-250° C. and the adsorption time is 1-12 h.

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