An oil sludge demulsifier, a preparation method and application thereof

Abstract

This application relates to the field of demulsifiers, and more specifically, to an oil sludge demulsifier, its preparation method, and its application. An oil sludge demulsifier comprises the following components in the following mass ratio: 20-35 parts of a surfactant complex, 7-12 parts of an alkyl sulfate sodium cosolvent, 0.6-1.8 parts of a stabilizer, and 48-55 parts of water; wherein the surfactant complex comprises hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles. This oil sludge demulsifier improves upon the problems of existing demulsifiers, such as low dehydration capacity, slow dehydration speed, poor demulsification effect, and low oil content, thereby improving the demulsification performance and dehydration efficiency, and achieving effective separation of oil sludge.

Description

Technical Field

[0001] This application relates to the field of demulsifiers, and more specifically, to an oil sludge demulsifier, its preparation method, and its application. Background Technology

[0002] With the development of technologies in industries such as oil and gas shale gas extraction, oil processing, and coking, a large amount of oily sludge is generated every year. During the extraction, gathering, transportation, refining, and treatment of oily wastewater, a large amount of black, oily solid and semi-solid waste, known as oily sludge, is produced. Oily sludge is a stable colloidal system composed mainly of petroleum, mud, and water. In addition to heavy crude oil, residual oil, and refined oil products, petroleum contains large amounts of toxic and harmful substances such as benzene compounds, phenols, anthracene, pyrene, polychlorinated biphenyls (PCBs), and dioxins. Furthermore, oily sludge contains a large number of pathogens and parasites. If not properly and effectively treated, it will not only waste petroleum resources but also cause serious environmental pollution. It has been classified as a Class (HW08) hazardous waste in my country and must be effectively treated and rendered harmless before being discharged.

[0003] Because oil sludge is a stable colloidal system, water droplets are difficult to aggregate. Therefore, most of the water is dispersed in the crude oil as extremely small particles, forming a stable crude oil emulsion, which poses a significant challenge to oil-water separation. In oil sludge treatment, it is necessary to first break down the oil-water interface film to separate the oil and water, thereby achieving three-phase separation of oil, water, and sludge / sand. In recent years, chemical demulsification has become the most widely used demulsification method in oilfields. However, most currently used demulsifiers suffer from low dehydration capacity, slow dehydration speed, poor demulsification effect, and limited processing capacity for oil sludge with low oil content, significantly reducing the treatment efficiency of oil sludge / sand. Therefore, seeking new demulsifiers with excellent demulsification performance and broad applicability, or improving demulsification processes to enhance demulsification and dehydration efficiency, remains a significant challenge for the future. Summary of the Invention

[0004] In order to improve the demulsification performance of oil sludge demulsifier, increase the demulsification and dehydration efficiency, and achieve effective separation of oil sludge, this application provides an oil sludge demulsifier, its preparation method, and its application.

[0005] In a first aspect, this application provides an oil sludge demulsifier, which adopts the following technical solution: An oil sludge demulsifier comprises the following components in the following mass ratio: 20-35 parts of a surfactant complex, 7-12 parts of an alkyl sulfate sodium cosolvent, 0.6-1.8 parts of a stabilizer, and 48-55 parts of water; wherein the surfactant complex comprises hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles.

[0006] By employing the above technical solution, the hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles in the surface-active composite can effectively promote the aggregation of oil droplets in oil sludge, significantly improving oil-water separation efficiency. This results in oil sludge with complex emulsion structures exhibiting a higher demulsification effect, with advantages such as a clear oil / water interface and low energy consumption, while reducing the difficulty and cost of subsequent processing. Through the polyether amine modified magnetic nanoparticles, the positively charged nanoparticles can adsorb the protective film formed at the oil-water interface in the oil sludge and generate electrostatic attraction with the negatively charged oil droplets in the oil sludge, weakening the interfacial repulsion between the oil-water and oil-sludge interfaces. The original oil-water and oil-sludge interfacial films are destroyed, leading to demulsification, dehydration, and deoiling, ultimately forming a three-phase stratification of oil, water, and sludge. Polyether amine possesses high interfacial activity and can rapidly diffuse into the oil phase, preventing the migration of active substances from the bulk phase of the oil sludge to the interface, thus preventing the formation of an unstable mixed film. This, in turn, reduces the interfacial film strength and destroys the interfacial film, achieving directional demulsification.

[0007] The addition of hyperbranched polyamide amine serves two main purposes. First, the unique dendritic structure of hyperbranched polyamide amine, with its abundant hydrophilic amino functional groups on its branches, promotes the rapid arrival of polyetheramine-modified magnetic nanoparticles at the oil-water interface, further improving demulsification efficiency. Second, the large number of amino groups can form hydrogen bonds with asphalt and other substances in the sludge, thereby strongly binding with the protective film at the oil-water and oil-sludge interfaces through electrostatic forces and hydrogen bonds. This disrupts the protective film at the oil-water and oil-sludge interfaces, allowing oil droplets to be released and coalesce to form the oil phase, thus achieving three-phase separation. Simultaneously, the addition of sodium alkyl sulfate cosolvents and stabilizers ensures the wetting and penetration capabilities and flocculation performance of the sludge demulsifier in practical applications, significantly improving the demulsification and dehydration efficiency of the sludge and reducing the water content of the separated crude oil.

[0008] In one specific implementation scheme, the preparation method of the polyetheramine modified magnetic nanoparticles is as follows: (1) ferromagnetic Fe3O4 is dispersed in an ethanol solution, hexadecyltrimethylammonium bromide is added, ultrasonically dispersed for 30-45 min, 2-5 mL TEOS and 0.5-1 mL APTES are added dropwise, stirred at 40-45℃ for 12-16 h, centrifuged, washed, and dried to obtain Fe3O4@SiO2-NH2; (2) The above Fe3O4@SiO2-NH2 was dispersed in toluene, PEA and 0.1-0.5 mL of glutaraldehyde were added, and the mixture was refluxed at 100-120 °C for 16-24 h under nitrogen protection. The product was collected by magnetic separation, washed, and dried to obtain polyetheramine modified... Magnetic nanoparticles.

[0009] The mass ratio of Fe3O4@SiO2-NH2 to PEA is 1:(2-5).

[0010] By employing the above technical solution, ferromagnetic Fe3O4 is first dispersed in an ethanol solution. Using hexadecyltrimethylammonium bromide as a template agent, hollow SiO2 particles are formed, which are then coated with Fe3O4 during the reaction. This results in a mesoporous shell with a large specific surface area and pore volume, thereby increasing the chemical modification sites of the Fe3O4@SiO2 shell structure. Then, PEA is grafted using glutaraldehyde as a crosslinking agent to obtain polyetheramine-modified magnetic nanoparticles. By controlling the mass ratio of Fe3O4@SiO2-NH2 to PEA, the grafting efficiency is optimized, ensuring both hydrophilicity and adsorption-emulsification efficiency, thus more effectively disrupting the oil-water interface film. Insufficient Fe3O4@SiO2-NH2 content leads to low adsorption-emulsification efficiency and reduced clarity of the oil-water interface.

[0011] In one specific implementation, the mass ratio of the hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles is (0.6-0.8):1.

[0012] By adopting the above technical solution, and using a mixture of hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles in a certain range, the hyperbranched polyamide amine with rich branches can effectively disperse the polyether amine modified magnetic nanoparticles at the oil-water interface, enhance the wetting and penetration ability, achieve efficient demulsification, and improve the dehydration speed and dehydration rate of oil sludge. If the content of polyether amine modified magnetic nanoparticles is too low, the adsorption and emulsification properties of the demulsifier will be poor at the same time, and the dehydration rate will be reduced.

[0013] In one specific implementation, the sodium alkyl sulfate cosolvent is sodium dodecyl sulfate.

[0014] Sodium dodecyl sulfate has emulsifying and dispersing properties that can enhance the penetration and charge neutralization of surfactant complexes. In turn, the hydrophilicity and penetrating ability of surfactant complexes can further improve the emulsifying effect of sodium dodecyl sulfate, thereby resulting in higher efficiency and stability during demulsification.

[0015] In one specific implementation, the stabilizer includes organic alcohol amines and polyvinylpyrrolidone.

[0016] Preferably, the mass ratio of organic alcohol amine to polyvinylpyrrolidone is (0.2-0.3):1.

[0017] By adopting the above technical solution, the combined action of a certain range of organic alcohol amines and polyvinylpyrrolidone can significantly improve the dewatering efficiency of oil sludge and enhance the demulsification and flocculation effects. Organic alcohol amines can be adsorbed on the surface of oil droplets, making them easier to combine with other oil droplets or flocs. PVP can combine with charged particles in oil sludge, neutralize their surface charge, reduce the electrostatic repulsion between particles, and accelerate the formation and sedimentation of oil sludge flocs, which can significantly improve the oil sludge treatment efficiency.

[0018] Secondly, this application provides a method for preparing an oil sludge demulsifier, which adopts the following technical solution: A method for preparing an oil sludge demulsifier includes the following steps: adding a surface-active complex, sodium alkyl sulfate cosolvent, stabilizer and water to a stirred tank in proportion, and stirring for 1-2 hours to obtain the oil sludge demulsifier.

[0019] The stirring temperature is 60-70℃ and the stirring speed is 150-250r / min.

[0020] Thirdly, this application provides an application of an oil sludge demulsifier in oil sludge treatment.

[0021] Preferably, the application method involves adding an oil sludge demulsifier to the oil sludge, with an addition amount of 12 mL of oil sludge demulsifier per 50 g of oil sludge. After thorough mixing, the oil sludge is demulsified and dehydrated at 45°C.

[0022] In summary, this application has the following beneficial effects: 1. The hyperbranched polyamide amine and polyether amine-modified magnetic nanoparticles in the surfactant complex can effectively promote the aggregation of oil droplets in oil sludge, significantly improving oil-water separation efficiency. This results in oil sludge with complex emulsion structures exhibiting a higher demulsification effect, with advantages such as a clear oil / water interface and low energy consumption, while reducing the difficulty and cost of subsequent processing. The polyether amine-modified magnetic nanoparticles reduce the strength of the interfacial film, causing it to break down and achieving directional demulsification. The addition of hyperbranched polyamide amine, with its abundant hydrophilic amino functional groups on the branches, promotes the rapid arrival of the polyether amine-modified magnetic nanoparticles at the oil-water interface, further improving demulsification efficiency. The numerous amino groups can form hydrogen bonds with asphalt and other substances in the oil sludge, and then strongly bind to the protective film at the oil-water and oil-sludge interfaces through electrostatic forces and hydrogen bonds, destroying the protective film at the oil-water and oil-sludge interfaces, thereby achieving three-phase separation. Meanwhile, the addition of sodium alkyl sulfate cosolvents and stabilizers ensures the wetting and penetration ability and flocculation performance of the sludge demulsifier in practical applications, which can significantly improve the demulsification and dehydration efficiency of sludge and reduce the water content of crude oil after separation.

[0023] 2. First, ferromagnetic Fe3O4 is dispersed in an ethanol solution. Using hexadecyltrimethylammonium bromide as a template agent, hollow SiO2 particles are formed and coated with Fe3O4 during the reaction. This results in a large specific surface area and pore volume of the mesoporous shell, thereby increasing the chemical modification sites of the Fe3O4@SiO2 shell structure. Then, PEA is grafted using glutaraldehyde as a crosslinking agent to obtain polyetheramine-modified magnetic nanoparticles. By controlling the mass ratio of Fe3O4@SiO2-NH2 to PEA, the grafting efficiency is optimized, ensuring both hydrophilicity and adsorption-emulsification efficiency, thus more effectively disrupting the oil-water interface film. Insufficient Fe3O4@SiO2-NH2 content leads to low adsorption-emulsification efficiency and reduced clarity of the oil-water interface.

[0024] 3. The combined action of organic alcohol amines and polyvinylpyrrolidone (PVP) within a certain range can significantly improve the dewatering efficiency of oil sludge and enhance the demulsification and flocculation effects. Organic alcohol amines can adsorb onto the surface of oil droplets, making them easier to combine with other oil droplets or flocs. PVP can combine with charged particles in oil sludge, neutralize their surface charge, reduce the electrostatic repulsion between particles, and accelerate the formation and sedimentation of oil sludge flocs, thus significantly improving the oil sludge treatment efficiency. Detailed Implementation

[0025] The present application will be further described in detail below with reference to the embodiments.

[0026] Some of the raw materials used in the preparation examples and embodiments: hyperbranched polyamide amine: CY-8872; sodium dodecyl sulfate: BASF; organic alcohol amine: AMP-95; ferromagnetic Fe3O4: Brofos-Fe3O4.

[0027] Unless otherwise specified, all raw materials used in the examples and comparative examples are commercially available products.

[0028] Preparation Example 1 0.5 g of ferromagnetic Fe3O4 was dispersed in 80 ml of ethanol solution (ethanol:water = 4:1), 1 g of hexadecyltrimethylammonium bromide was added, and the mixture was ultrasonically dispersed for 30-45 min. 2.5 mL of TEOS and 1 mL of APTES were added dropwise, and the mixture was stirred at 45 °C for 12 h. After centrifugation, washing, and drying, Fe3O4@SiO2-NH2 was obtained. The above 0.3g Fe3O4@SiO2-NH2 was dispersed in 50mL toluene, and 0.6g PEA and 0.1mL glutaraldehyde were added. Under nitrogen protection, the mixture was refluxed at 100℃ for 24h. The product was collected by magnetic separation, washed successively with toluene and ethanol, and dried under vacuum at 60℃ to obtain polyetheramine modified magnetic nanoparticles.

[0029] Preparation Example 2 0.5 g of ferromagnetic Fe3O4 was dispersed in 80 ml of ethanol solution (ethanol:water = 4:1), 1 g of hexadecyltrimethylammonium bromide was added, and the mixture was ultrasonically dispersed for 30-45 min. 2.5 mL of TEOS and 1 mL of APTES were added dropwise, and the mixture was stirred at 45 °C for 12 h. After centrifugation, washing, and drying, Fe3O4@SiO2-NH2 was obtained. The above 0.3g Fe3O4@SiO2-NH2 was dispersed in 50mL toluene, 1.2g PEA and 0.1mL glutaraldehyde were added, and the mixture was refluxed at 100℃ for 24h under nitrogen protection. The product was collected by magnetic separation, washed successively with toluene and ethanol, and dried under vacuum at 60℃ to obtain polyetheramine modified magnetic nanoparticles.

[0030] Preparation Example 3 0.5 g of ferromagnetic Fe3O4 was dispersed in 80 ml of ethanol solution (ethanol:water = 4:1), 1 g of hexadecyltrimethylammonium bromide was added, and the mixture was ultrasonically dispersed for 30-45 min. 2.5 mL of TEOS and 1 mL of APTES were added dropwise, and the mixture was stirred at 45 °C for 12 h. After centrifugation, washing, and drying, Fe3O4@SiO2-NH2 was obtained. The above 0.2g Fe3O4@SiO2-NH2 was dispersed in 50mL toluene, and 0.7g PEA and 0.1mL glutaraldehyde were added. Under nitrogen protection, the mixture was refluxed at 100℃ for 24h. The product was collected by magnetic separation, washed successively with toluene and ethanol, and dried under vacuum at 60℃ to obtain polyetheramine modified magnetic nanoparticles.

[0031] Preparation Example 4 0.5 g of ferromagnetic Fe3O4 was dispersed in 80 ml of ethanol solution (ethanol:water = 4:1), 1 g of hexadecyltrimethylammonium bromide was added, and the mixture was ultrasonically dispersed for 30-45 min. 2.5 mL of TEOS and 1 mL of APTES were added dropwise, and the mixture was stirred at 45 °C for 12 h. After centrifugation, washing, and drying, Fe3O4@SiO2-NH2 was obtained.

[0032] Preparation Example 5 Add 1 g of hexadecyltrimethylammonium bromide to 80 ml of ethanol solution (ethanol:water = 4:1), sonicate for 30-45 min, add 2.5 mL of TEOS and 1 mL of APTES dropwise, stir at 45 °C for 12 h, centrifuge, wash, and dry to obtain SiO2-NH2; The above 0.3g SiO2-NH2 was dispersed in 50mL toluene, and 0.6g PEA and 0.1mL glutaraldehyde were added. Under nitrogen protection, the mixture was refluxed at 100℃ for 24h. The product was collected by filtration, washed successively with toluene and ethanol, and dried under vacuum at 60℃ to obtain polyetheramine modified nanoparticles.

[0033] Example 1 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyetheramine modified magnetic nanoparticles prepared in Example 1 in a mass ratio of 0.8:1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0034] Example 2 An oil sludge demulsifier comprises the following components in the following mass ratio: 30g of a surfactant complex, 7g of an alkyl sulfate sodium cosolvent, 1.5g of a stabilizer, and 50g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles in a mass ratio of 0.8:1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 2 hours at 70℃ and 150 r / min to obtain the sludge demulsifier.

[0035] Example 3 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles prepared in Example 1 in a mass ratio of 0.6:1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0036] Example 4 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is a hyperbranched polyamide amine and polyetheramine-modified magnetic nanoparticles prepared in Example 1 in a mass ratio of 1.2:0.6; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0037] Example 5 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles prepared in Preparation Example 2 in a mass ratio of 0.8:1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0038] Example 6 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles prepared in Example 3 in a mass ratio of 0.8:1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0039] Example 7 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles prepared in Example 1 in a mass ratio of 0.8:1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.3:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0040] Example 8 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles prepared in Preparation Example 1 in a mass ratio of 0.8:1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0041] Example 9 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyetheramine modified magnetic nanoparticles prepared in Preparation Example 1 in a mass ratio of 0.8:1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is polyvinylpyrrolidone. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0042] Comparative Example 1 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is a hyperbranched polyamide amine; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0043] Comparative Example 2 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is the polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0044] Comparative Example 3 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles prepared in Example 4 in a mass ratio of 0.8:1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0045] Comparative Example 4 An oil sludge demulsifier comprises the following components in the following mass ratio: 25g of a surfactant complex, 10g of an alkyl sulfate sodium cosolvent, 0.8g of a stabilizer, and 48g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles prepared in Example 5 in a mass ratio of 0.8:1; the alkyl sulfate sodium cosolvent is sodium dodecyl sulfate; and the stabilizer is an organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water are added to a stirred tank in proportion and stirred for 1 hour at 60℃ and 220 r / min to obtain the sludge demulsifier.

[0046] Comparative Example 5 An oil sludge demulsifier comprises the following components in the following mass ratio: 25 g of a surfactant complex, 0.8 g of a stabilizer, and 58 g of water; wherein the surfactant complex is hyperbranched polyamide amine and polyether amine modified magnetic nanoparticles prepared in Example 1 in a mass ratio of 0.8:1; the stabilizer is organic alcohol amine and polyvinylpyrrolidone in a mass ratio of 0.2:1. The surfactant complex, stabilizer, and water are added to a stirred tank in proportion and stirred for 1 hour at 60°C and 220 r / min to obtain the sludge demulsifier.

[0047] Performance testing The application method of the sludge demulsifier prepared in the above examples and comparative examples is as follows: Add the sludge demulsifier to 12 mL of 50 g of sludge from the Bohai Oilfield with an oil content of 15%. Stir the mixture thoroughly on a magnetic stirrer at 500 rpm for 10 minutes. Then, perform sludge demulsification and dehydration treatment at 45°C. The time required for the demulsification and dehydration rate to reach 90% when the sludge is placed on a U85 teaching magnet is recorded. The dehydration effect is shown below: Table 1 Performance Test Results

[0048] As can be seen from Table 1, the sludge demulsifier obtained in the above embodiments acts on the sludge, improves the demulsification and dehydration efficiency, and achieves effective separation of the sludge. The sludge demulsifier has good demulsification performance. Comparative Examples 1-4 and 1-2 show that the mixed use of hyperbranched polyamide amine and polyetheramine-modified magnetic nanoparticles within a certain range allows the highly branched hyperbranched polyamide amine to effectively disperse the polyetheramine-modified magnetic nanoparticles at the oil-water interface, enhancing wetting and penetration capabilities, achieving efficient demulsification, and improving the dehydration speed and rate of sludge. The positively charged polyetheramine-modified magnetic nanoparticles can adsorb the protective film formed at the oil-water interface in the sludge, effectively adsorbing and disrupting the sludge interface, ultimately forming a three-phase stratification of oil, water, and sludge. This allows for directional demulsification through wetting and penetration capabilities and rapid diffusion adsorption. If the content of polyetheramine-modified magnetic nanoparticles is too low, the adsorption and emulsification properties of the demulsifier at the same time are poor, resulting in a reduced dehydration rate.

[0049] As shown in Examples 1, 5-6, and Comparative Examples 3-4, the hollow SiO2 coating of Fe3O4 in this application results in a large specific surface area and pore volume of the mesoporous shell, thereby increasing the chemical modification sites for PEA grafting in the Fe3O4@SiO2 shell structure. This ensures its hydrophilicity and adsorption emulsification efficiency, thus more effectively disrupting the oil-water interface film. A low Fe3O4@SiO2-NH2 content leads to low adsorption emulsification efficiency, an uneven water-oil interface, and reduced clarity.

[0050] Comparative Examples 7-9 show that the applicant believes that a certain range of organic alcohol amines and polyvinylpyrrolidone have the combined effect of significantly improving the dehydration efficiency of oil sludge, enhancing demulsification and flocculation effects, and can be adsorbed on the surface of oil droplets, making them easier to combine with other oil droplets or flocs, accelerating the formation and sedimentation of oil sludge flocs, improving the stability of oil sludge demulsification and dehydration, and maintaining a clear interface.

[0051] Comparative Example 1 and Comparative Example 5 show that sodium dodecyl sulfate has emulsifying and dispersing properties that can enhance the penetration and charge neutralization of the surfactant complex. The hydrophilicity and penetration ability of the surfactant complex can further improve the emulsifying effect of sodium dodecyl sulfate, thereby exhibiting higher efficiency and stability during the demulsification process and maintaining interface level and clarity.

[0052] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A sludge demulsifier, characterized in that: The components include the following mass ratio: 20-35 parts of surface active complex, 7-12 parts of sodium alkyl sulfate cosolvent, 0.6-1.8 parts of stabilizer and 48-55 parts of water; wherein, the surface active complex is a hyperbranched polyamide amine and polyether amine modified magnetic nanoparticle with a mass ratio of (0.6-0.8):1; the preparation method of the polyether amine modified magnetic nanoparticle is as follows: (1) Disperse ferromagnetic Fe3O4 in ethanol solution, add hexadecyltrimethylammonium bromide, ultrasonically disperse for 30-45 min, add 2-5 mL TEOS and 0.5-1 mL APTES dropwise, stir at 40-45℃ for 12-16 h, centrifuge and wash, and dry to obtain Fe3O4@SiO2-NH2; (2) The above Fe3O4@SiO2-NH2 was dispersed in toluene, PEA and 0.1-0.5 mL of glutaraldehyde were added, and the mixture was refluxed at 100-120 °C for 16-24 h under nitrogen protection. The product was collected by magnetic separation, washed and dried to obtain polyetheramine modified magnetic nanoparticles. The mass ratio of Fe3O4@SiO2-NH2 to PEA was 1:(2-5). The stabilizer was an organic alcohol amine and polyvinylpyrrolidone.

2. The sludge demulsifier according to claim 1, characterized in that: The alkyl sulfate cosolvent is sodium dodecyl sulfate.

3. The method for preparing the sludge demulsifier according to any one of claims 1-2, characterized in that: The process includes the following steps: adding the surfactant complex, sodium alkyl sulfate cosolvent, stabilizer and water to a stirred tank in proportion, and stirring for 1-2 hours to obtain the sludge demulsifier.

4. The method for preparing the sludge demulsifier according to claim 3, characterized in that, The stirring temperature is 60-70℃ and the stirring speed is 150-250r / min.

5. The application of the sludge demulsifier according to any one of claims 1-2 in sludge treatment.

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