Oil sludge demulsifier as well as preparation method and application thereof

Abstract

The invention relates to the field of demulsifiers, in particular to an oil sludge demulsifier as well as a preparation method and application thereof. The oil sludge demulsifier comprises the following components in parts by mass: 20-35 parts of a surface active compound, 7-12 parts of a sodium alkyl sulfate cosolvent, 0.6-1.8 parts of a stabilizer and 48-55 parts of water, wherein the surface active compound comprises hyperbranched polyamidoamine and polyether amine modified magnetic nanoparticles. According to the oil sludge demulsifier, the problems that most of existing demulsifiers are small in dehydration amount, low in dehydration speed, poor in demulsification effect and low in treated oil content are solved, the demulsification performance of the oil sludge demulsifier is improved, the demulsification and dehydration efficiency is improved, and effective separation of oil sludge is achieved.

Description

Technical Field

[0001] The present application relates to the field of demulsifiers, and more specifically, to an oil sludge demulsifier and a preparation method and application thereof. Background Art

[0002] With technological advancements in industries such as oil and natural gas shale gas extraction, oil processing, and coking, large quantities of oily sludge are generated annually. The extraction, transportation, refining, and treatment of oily wastewater produce large quantities of oily black solid and semi-solid waste, known as oil sludge. Oil sludge is primarily composed of a stable colloidal system of oil, mud, and water. In addition to heavy crude oil, residual oil, and refined oil, oil contains significant quantities of toxic and hazardous substances such as benzene, phenols, anthracene, pyrene, polychlorinated biphenyls, and dioxins. Furthermore, oil sludge contains numerous pathogens and parasites. Without proper and effective treatment, it not only wastes oil resources but also causes severe environmental pollution. It has been classified as a Class (HW08) hazardous waste in my country and must undergo effective treatment to render it harmless before discharge.

[0003] Because oil sludge is a stable colloidal system, it is difficult for water droplets to coalesce. Therefore, most of the water is dispersed in the crude oil as extremely small particles to form a stable crude oil emulsion, which brings great difficulties to oil-water separation. In the oil sludge treatment process, it is necessary to first break the oil-water interface membrane to separate the oil and water from each other, and then achieve the three-phase separation of oil, water and mud and sand. In recent years, chemical demulsification has been the most widely used demulsification method in oil fields. However, most of the demulsifiers currently used have the problems of small dehydration capacity, slow dehydration speed, poor demulsification effect, and can only treat oil sludge with low oil content. The treatment is limited and the efficiency of oil sludge and sand treatment is greatly reduced. Therefore, seeking new demulsifiers with excellent demulsification performance and strong applicability or improving the demulsification process to improve the demulsification and dehydration efficiency remains a huge challenge in the future. Summary of the Invention

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

[0005] In the first aspect, the present application provides an oil sludge demulsifier, which adopts the following technical solution: A sludge demulsifier comprises the following components in the following mass ratios: 20-35 parts of a surfactant compound, 7-12 parts of a sodium alkyl sulfate cosolvent, 0.6-1.8 parts of a stabilizer, and 48-55 parts of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles.

[0006] By adopting the above technical solution, the hyperbranched polyamide amine and polyetheramine modified magnetic nanoparticles in the surfactant complex can effectively promote the aggregation of oil droplets in the sludge, significantly improving the oil-water separation efficiency, thereby making the sludge with a complex emulsion structure show a higher demulsification effect, with the advantages of clear oil / water interface and low energy consumption, and reducing the difficulty and cost of subsequent treatment. Through the polyetheramine modified magnetic nanoparticles, the positively charged polyetheramine modified magnetic nanoparticles can adsorb the protective film formed at the oil-water interface in the sludge, and generate electrostatic attraction with the negatively charged oil droplets in the sludge, weakening the interfacial repulsion between the oil-water and sludge interfaces, destroying the original oil-water interface film and the sludge interface film, resulting in demulsification, dehydration and deoiling, and ultimately forming a three-phase stratification of oil, water and sludge; the polyetheramine has high interfacial activity and can quickly diffuse into the oil phase, preventing the migration of active substances in the sludge bulk phase to the interface and forming an unstable mixed film, thereby reducing the strength of the interfacial film and destroying the interfacial film, achieving directional demulsification.

[0007] The addition of hyperbranched polyamidoamine, on the one hand, has a unique tree-like structure, and the abundant hydrophilic amino functional groups on its side chains can promote the rapid arrival of polyetheramine-modified magnetic nanoparticles at the oil-water interface, further improving demulsification efficiency. On the other hand, the large number of amino groups can form hydrogen bonds with asphalt and other substances in the sludge, and then strongly bind to the protective film at the oil-water and oil-sludge interfaces in the sludge through electrostatic forces and hydrogen bonds, destroying the protective film at the oil-water and oil-sludge interfaces, allowing the oil droplets to be released and coalesced to form an oil phase, thereby achieving three-phase separation. At the same time, the addition of sodium alkyl sulfate cosolvents and stabilizers ensures the wetting, penetration, and flocculation properties of the sludge demulsifier in practical applications, significantly improving the demulsification and dehydration efficiency of the sludge and reducing the water content of the crude oil after separation.

[0008] In a specific embodiment, the preparation method of the polyetheramine modified magnetic nanoparticles is as follows: (1) dispersing ferromagnetic Fe3O4 in an ethanol solution, adding hexadecyltrimethylammonium bromide, ultrasonically dispersing for 30-45 minutes, adding 2-5 mL TEOS and 0.5-1 mL APTES dropwise, stirring at 40-45°C for 12-16 hours, centrifuging and washing, and drying to obtain Fe3O4@SiO2-NH2; (2) The above-mentioned 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 the Fe3O4@SiO2-NH2 and PEA is 1:(2-5).

[0010] By adopting the above technical solution, ferromagnetic Fe3O4 is first dispersed in an ethanol solution and hexadecyltrimethylammonium bromide is used as a template to form SiO2 particles with a hollow structure. During the reaction, the Fe3O4 is coated, resulting in a large specific surface area and pore volume of the mesoporous structure of the shell, thereby increasing the chemical modification sites of the Fe3O4@SiO2 shell structure. PEA is then grafted using glutaraldehyde as a crosslinker to obtain polyetheramine-modified magnetic nanoparticles. By controlling the mass ratio of Fe3O4@SiO2-NH2 and PEA, the grafting efficiency is optimized and improved, thereby ensuring its hydrophilicity and adsorption and emulsification efficiency, thereby more effectively destroying the oil-water interface film. If the Fe3O4@SiO2-NH2 content is too low, the adsorption and emulsification efficiency will be low, and the clarity of the water-oil interface will be reduced.

[0011] In a specific embodiment, the mass ratio of the hyperbranched polyamidoamine and polyetheramine modified magnetic nanoparticles is (0.6-0.8):1.

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

[0013] In a specific embodiment, the sodium alkyl sulfate cosolvent is sodium dodecyl sulfate.

[0014] The emulsifying and dispersing properties of sodium lauryl sulfate can enhance the penetration and charge neutralization effects of the surfactant complex, while the hydrophilicity and penetration ability of the surfactant complex can further improve the emulsifying effect of sodium lauryl sulfate, thereby achieving higher efficiency and stability in the demulsification process.

[0015] In a specific embodiment, the stabilizer includes organic alcohol amine and polyvinyl pyrrolidone.

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

[0017] By adopting the above technical solution, the combined effect of organic alcohol amines and polyvinyl pyrrolidone in a certain range of proportions can significantly improve the dehydration efficiency of sludge and enhance the effects of demulsification and flocculation; organic alcohol amines can adsorb on the surface of oil droplets, making it easier for them to combine with other oil droplets or flocs; PVP can combine with charged particles in the sludge, neutralize their surface charge, reduce the electrostatic repulsion between particles, accelerate the formation and sedimentation of sludge flocs, and significantly improve the efficiency of sludge treatment.

[0018] In a second aspect, the present application provides a method for preparing an oil sludge demulsifier, which adopts the following technical solution: A method for preparing an oil sludge demulsifier comprises the following steps: adding a surfactant compound, an alkyl sodium sulfate cosolvent, a stabilizer and water into a stirring kettle in proportion, and stirring for 1-2 hours to obtain the oil sludge demulsifier.

[0019] The stirring temperature is 60-70° C., and the rotation speed is 150-250 r / min.

[0020] In a third aspect, the present application provides an application of an oil sludge demulsifier in oil sludge treatment.

[0021] Preferably, the application method is to add an oil sludge demulsifier to the oil sludge in an amount of 12 mL of the oil sludge demulsifier to every 50 g of the oil sludge, and after thorough mixing, perform an oil sludge demulsification and dehydration treatment at 45°C.

[0022] In summary, this application has the following beneficial effects: 1. Hyperbranched polyamidoamine and polyetheramine-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 allows sludge with complex emulsion structures to exhibit 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 polyetheramine-modified magnetic nanoparticles reduce the strength of the interfacial film and destroy the interfacial film, achieving directional demulsification. The addition of hyperbranched polyamidoamine, with its abundant hydrophilic amino functional groups on the side chains, promotes the rapid arrival of the polyetheramine-modified magnetic nanoparticles at the oil-water interface, further improving demulsification efficiency. The large number of amino groups can form hydrogen bonds with asphalt in the oil sludge, and then strongly bind to the protective film at the oil-water and oil-sludge interfaces in the oil sludge through electrostatic forces and hydrogen bonds, destroying the protective film at the oil-water and oil-sludge interfaces, thereby achieving three-phase separation. At the same time, the addition of sodium alkyl sulfate cosolvents and stabilizers ensures the wetting, penetration and flocculation properties of the sludge demulsifier in practical applications, which can significantly improve the demulsification and dehydration efficiency of the sludge and reduce the water content of the crude oil after separation.

[0023] 2. First, ferromagnetic Fe3O4 is dispersed in an ethanol solution and hexadecyltrimethylammonium bromide is used as a template to form hollow SiO2 particles. During the reaction, Fe3O4 is coated, resulting 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. Glutaraldehyde is then used as a crosslinker to graft PEA to obtain polyetheramine-modified magnetic nanoparticles. By controlling the mass ratio of Fe3O4@SiO2-NH2 and PEA, the grafting efficiency is optimized and improved, thereby ensuring its hydrophilicity and adsorption and emulsification efficiency, thereby more effectively destroying the oil-water interface film. Too low a Fe3O4@SiO2-NH2 content leads to low adsorption and emulsification efficiency and reduced water-oil interface clarity.

[0024] 3. The combined effect of organic alcohol amines and polyvinyl pyrrolidone in a certain range of proportions can significantly improve the dehydration efficiency of sludge and enhance the effects of demulsification and flocculation. Organic alcohol amines can be adsorbed on the surface of oil droplets, making it easier for them to combine with other oil droplets or flocs. PVP can combine with charged particles in sludge, neutralize their surface charge, reduce the electrostatic repulsion between particles, accelerate the formation and sedimentation of sludge flocs, and significantly improve the efficiency of sludge treatment. DETAILED DESCRIPTION

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

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

[0027] The raw materials used in the examples and comparative examples that are not otherwise specified are all conventional products that can be purchased from the market.

[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 ultrasonic dispersion was performed 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. The mixture was washed by centrifugation and dried to obtain Fe3O4@SiO2-NH2. 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 reaction was refluxed at 100℃ for 24h. The product was collected by magnetic separation, washed with toluene and ethanol in sequence, and dried in 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 ultrasonic dispersion was performed 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. The mixture was washed by centrifugation and dried to obtain Fe3O4@SiO2-NH2. The above 0.3g Fe3O4@SiO2-NH2 was dispersed in 50mL toluene, and 1.2g PEA and 0.1mL glutaraldehyde were added. Under nitrogen protection, the reaction was refluxed at 100℃ for 24h. The product was collected by magnetic separation, washed with toluene and ethanol in sequence, and dried in 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 ultrasonic dispersion was performed 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. The mixture was washed by centrifugation and dried to obtain Fe3O4@SiO2-NH2. 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 reaction was refluxed at 100℃ for 24h. The product was collected by magnetic separation, washed with toluene and ethanol in sequence, and dried in 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 ultrasonic dispersion was performed 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. The mixture was centrifuged and washed, and dried to obtain Fe3O4@SiO2-NH2.

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

[0033] Example 1 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 1 in a mass ratio of 0.8:1; the sodium alkyl sulfate cosolvent comprises sodium lauryl sulfate; and the stabilizer comprises an organic alcoholamine and polyvinylpyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0034] Example 2 A sludge demulsifier comprising the following components in the following mass ratios: 30 g of a surfactant compound, 7 g of a sodium alkyl sulfate cosolvent, 1.5 g of a stabilizer, and 50 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles in a mass ratio of 0.8:1; the sodium alkyl sulfate cosolvent comprises sodium lauryl sulfate; and the stabilizer comprises an organic alcohol amine and polyvinyl pyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 70°C and a rotation speed of 150 r / min for 2 hours to obtain the sludge demulsifier.

[0035] Example 3 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 1 in a mass ratio of 0.6:1; the sodium alkyl sulfate cosolvent comprises sodium lauryl sulfate; and the stabilizer comprises an organic alcohol amine and polyvinyl pyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0036] Example 4 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 1 in a mass ratio of 1.2:0.6; the sodium alkyl sulfate cosolvent comprises sodium lauryl sulfate; and the stabilizer comprises an organic alcohol amine and polyvinyl pyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0037] Example 5 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 2 in a mass ratio of 0.8:1; the sodium alkyl sulfate cosolvent comprises sodium lauryl sulfate; and the stabilizer comprises an organic alcohol amine and polyvinyl pyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0038] Example 6 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 3 in a mass ratio of 0.8:1; the sodium alkyl sulfate cosolvent comprises sodium lauryl sulfate; and the stabilizer comprises an organic alcohol amine and polyvinyl pyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0039] Preparation Example 7 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 1 in a mass ratio of 0.8:1; the sodium alkyl sulfate cosolvent comprises sodium lauryl sulfate; and the stabilizer comprises an organic alcoholamine and polyvinylpyrrolidone in a mass ratio of 0.3:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0040] Example 8 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 1 in a mass ratio of 0.8:1; the sodium alkyl sulfate cosolvent comprises sodium lauryl sulfate; and the stabilizer comprises an organic alcoholamine. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0041] Example 9 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 1 in a mass ratio of 0.8:1; the sodium alkyl sulfate cosolvent is sodium lauryl sulfate; and the stabilizer is polyvinyl pyrrolidone; Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0042] Comparative Example 1 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound is a hyperbranched polyamidoamine; the sodium alkyl sulfate cosolvent is sodium lauryl sulfate; and the stabilizer is an organic alcohol amine and polyvinyl pyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0043] Comparative Example 2 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound is the polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 1; the sodium alkyl sulfate cosolvent is sodium lauryl sulfate; and the stabilizer is an organic alcohol amine and polyvinyl pyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0044] Comparative Example 3 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 4 in a mass ratio of 0.8:1; the sodium alkyl sulfate cosolvent comprises sodium lauryl sulfate; and the stabilizer comprises an organic alcohol amine and polyvinyl pyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0045] Comparative Example 4 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 10 g of a sodium alkyl sulfate cosolvent, 0.8 g of a stabilizer, and 48 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 5 in a mass ratio of 0.8:1; the sodium alkyl sulfate cosolvent comprises sodium lauryl sulfate; and the stabilizer comprises an organic alcohol amine and polyvinyl pyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, sodium alkyl sulfate cosolvent, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the sludge demulsifier.

[0046] Comparative Example 5 A sludge demulsifier comprising the following components in the following mass ratios: 25 g of a surfactant compound, 0.8 g of a stabilizer, and 58 g of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles prepared in Preparation Example 1 in a mass ratio of 0.8:1; and the stabilizer comprises an organic alcohol amine and polyvinyl pyrrolidone in a mass ratio of 0.2:1. Add the surfactant compound, stabilizer and water into a stirring tank in proportion, stir at a temperature of 60°C and a rotation speed of 220 r / min for 1 hour to obtain the oil sludge demulsifier.

[0047] Performance testing The demulsifiers prepared in the examples and comparative examples were applied to Bohai oilfield sludge with a 15% oil content. The demulsifier was added at a rate of 12 mL per 50 g of sludge. The mixture was stirred on a magnetic stirrer at 500 rpm for 10 minutes to thoroughly mix the mixture. The mixture was then demulsified and dehydrated at 45°C. The demulsification rate reached 90% when placed on a U85 teaching magnet. The dehydration results are shown below: Table 1 Performance test results As can be seen from Table 1, the sludge demulsifier obtained in the above embodiment acts on the sludge, improves the demulsification and dehydration efficiency, and realizes the effective separation of the sludge. The sludge demulsifier has good demulsification performance; Comparing Examples 1-4 and Comparative Examples 1-2, it can be seen that the use of a mixture of hyperbranched polyamidoamine and polyetheramine-modified magnetic nanoparticles in a certain range of proportions allows the hyperbranched polyamidoamine with abundant branches to effectively disperse the polyetheramine-modified magnetic nanoparticles at the oil-water interface, enhancing its wetting and penetration capabilities, achieving efficient demulsification, and improving the sludge dehydration speed and dehydration rate. The positively charged polyetheramine-modified magnetic nanoparticles can adsorb the protective film formed at the oil-water interface in the sludge, effectively adsorbing and destroying the sludge interface, ultimately forming a three-phase separation of oil, water, and sludge; thus, directional demulsification is achieved through wetting and penetration capabilities and rapid diffusion and adsorption. If the content of polyetheramine-modified magnetic nanoparticles is too low, the demulsifier has poor adsorption and emulsification properties at the same time and a reduced dehydration rate.

[0048] As shown in Examples 1, 5-6, and Comparative Examples 3-4, the hollow SiO2-coated Fe3O4 shell structure of the present invention results in a significantly larger specific surface area and pore volume. This in turn increases the chemically modified sites of the Fe3O4@SiO2 shell structure for grafting PEA, thereby ensuring its hydrophilicity and adsorption and emulsification efficiency, thereby more effectively destroying the oil-water interface film. However, a low Fe3O4@SiO2-NH2 content results in low adsorption and emulsification efficiency, an uneven water-oil interface, and reduced clarity.

[0049] Comparative Examples 7-9 show that the applicant believes that a certain range of proportions of organic alcohol amine and polyvinyl pyrrolidone have the combined effect of significantly improving the dehydration efficiency of sludge, improving the demulsification and flocculation effects, and can be adsorbed on the surface of oil droplets, making it easier to combine with other oil droplets or flocs, accelerating the formation and sedimentation of sludge flocs, improving the demulsification and dehydration stability of sludge, and maintaining a clear interface.

[0050] Comparative Example 1 and Comparative Example 5 show that sodium lauryl sulfate has emulsifying and dispersing properties that can enhance the penetration and charge neutralization effect of the surfactant complex, while the hydrophilicity and penetration ability of the surfactant complex can further improve the emulsification effect of sodium lauryl sulfate, thereby showing higher efficiency and stability in the demulsification process and maintaining the interface level and clarity.

[0051] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. An oil sludge demulsifier, characterized by: The invention comprises the following components in the following mass ratios: 20-35 parts of a surfactant compound, 7-12 parts of an alkyl sodium sulfate cosolvent, 0.6-1.8 parts of a stabilizer and 48-55 parts of water; wherein the surfactant compound comprises hyperbranched polyamidoamine and polyetheramine modified magnetic nanoparticles.

2. The oil sludge demulsifier according to claim 1, characterized in that: The preparation method of the polyetheramine modified magnetic nanoparticles is as follows: (1) dispersing ferromagnetic Fe3O4 in an ethanol solution, adding hexadecyltrimethylammonium bromide, ultrasonically dispersing for 30-45 minutes, adding 2-5 mL TEOS and 0.5-1 mL APTES dropwise, stirring at 40-45° C. for 12-16 hours, centrifuging and washing, and drying to obtain Fe3O4@SiO2-NH2; (2) The above-mentioned Fe3O4@SiO2-NH2 was dispersed in toluene, and PEA and 0.1-0.5 mL of glutaraldehyde were added. Under nitrogen protection, the reaction was refluxed at 100-120 °C for 16-24 h. The product was collected by magnetic separation, washed, and dried to obtain polyetheramine-modified magnetic nanoparticles.

3. The oil sludge demulsifier according to claim 2, characterized in that: The mass ratio of Fe3O4@SiO2-NH2 and PEA is 1:(2-5).

4. The oil sludge demulsifier according to claim 1, characterized in that: The mass ratio of the hyperbranched polyamidoamine and polyetheramine modified magnetic nanoparticles is (0.6-0.8):

1.

5. The oil sludge demulsifier according to claim 1, characterized in that: The sodium alkyl sulfate cosolvent is sodium lauryl sulfate.

6. The oil sludge demulsifier according to claim 1, characterized in that: The stabilizer includes organic alcohol amine and polyvinyl pyrrolidone.

7. The method for preparing the oil sludge demulsifier according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: adding a surfactant compound, a sodium alkyl sulfate cosolvent, a stabilizer and water into a stirring kettle in proportion, and stirring for 1-2 hours to obtain an oil sludge demulsifier.

8. The method for preparing the oil sludge demulsifier according to claim 7, characterized in that: The stirring temperature is 60-70° C., and the rotation speed is 150-250 r / min.

9. Use of the oil sludge demulsifier according to any one of claims 1 to 6 in oil sludge treatment.

Images