Janus carbon sphere demulsifier as well as preparation method and application thereof
By introducing long-chain alkyl and quaternary ammonium groups on the surface of carbon spheres, the Janus carbon sphere demulsifier solves the complex preparation and environmental pollution problems of existing chemical demulsifiers and achieves efficient and green oil-water separation effects.
Patent Information
- Application Number
- CN202410321298.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-20
- Publication Date
- 2025-09-23
AI Technical Summary
Existing chemical demulsifiers have the problems of multiple reaction components, complex preparation process, expensive raw materials and environmental pollution. At the same time, they have strict requirements on the application environment, poor demulsification performance and poor adaptability.
Janus carbon sphere demulsifier is used to introduce long-chain alkyl hydrophobic groups and quaternary ammonium salt groups on different surfaces of thiol-modified carbon spheres to form an amphiphilic structure, reduce the oil-water interfacial tension, destroy the interfacial film, and achieve demulsification by utilizing the interaction between the hydrophobic long alkyl chain and the π conjugated system and the electrostatic neutralization effect of the quaternary ammonium salt.
Janus carbon ball demulsifier has excellent demulsification performance, strong adaptability, simple preparation method, and is environmentally friendly. It can effectively reduce the oil-water interfacial tension, promote oil-water separation, is suitable for complex environments, and is easy to separate and recycle.
Smart Images
Figure HDA0004750619180000011 
Figure HDA0004750619180000012
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of oilfield chemicals, and particularly relates to a Janus carbon ball demulsifier, a preparation method and an application thereof. Background Art
[0002] Crude oil contains natural emulsifiers, and water injection production introduces large amounts of water, resulting in the formation of stable crude oil emulsions, primarily in the form of W / O and O / W emulsions. These emulsions pose significant challenges to transportation and processing, and can also cause pipeline blockages and equipment corrosion. Therefore, demulsifying crude oil to achieve complete oil-water separation is crucial.
[0003] Chemical demulsifiers are widely used in crude oil demulsification due to their high activity and rapid effectiveness, and hold great promise for future development. In recent years, the most commonly used crude oil demulsifiers have primarily been polyethylene oxide (PEO) block copolymers and their derivatives. Modifications to traditional demulsifiers, such as head and tail modifications, chain extensions, grafting, crosslinking, and compounding, have primarily been employed to meet new requirements. While these demulsifiers and modification methods can improve demulsification efficiency, they still face challenges such as excessive reactive components, complex preparation processes, and expensive raw materials. Furthermore, after demulsification, the demulsifier can remain in the aqueous or oil phase, causing environmental pollution. Furthermore, while chemical demulsifiers offer rapid demulsification rates, they also impose stringent requirements on the application environment. Therefore, the development of new demulsifiers with simple, safe, and environmentally friendly production processes is urgent. Summary of the Invention
[0004] The object of the present invention is to overcome the problems and shortcomings of the above-mentioned prior art and to propose a Janus carbon sphere demulsifier. The Janus carbon sphere demulsifier has amphiphilicity and excellent surface and interfacial activity, can significantly reduce the oil-water interfacial tension, soften and / or destroy the oil-water interfacial film, and has good demulsification performance. It can effectively solve the problems of poor demulsification performance and poor adaptability in the prior art. The preparation method involved is relatively simple and easy to operate, making it suitable for promotion and application.
[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:
[0006] A Janus carbon ball demulsifier comprises mercapto-modified carbon balls and long-chain alkyl hydrophobic groups and quaternary ammonium salt groups respectively introduced on different surfaces of the carbon balls.
[0007] In the above scheme, the thiol-modified carbon spheres are obtained by dispersing bio-based carbon spheres, a thiol-modifying agent and a catalyst in an organic solvent and performing a solvothermal reaction.
[0008] In the above scheme, the thiol modifier can be selected from at least one of thioglycolic acid, mercaptopropionic acid, mercaptobutyric acid, etc.
[0009] Furthermore, the bio-based carbon spheres are obtained by dissolving glucose in water and reacting at 150-200° C. for 12-24 hours.
[0010] In the above scheme, the long-chain alkyl hydrophobic group is introduced by a click reaction between the thiol groups of the thiol-modified carbon spheres and the carbon-carbon double bonds in the long-chain olefins.
[0011] Furthermore, the long-chain olefin is an α-olefin, and the number of carbon atoms in the long chain is 12 or more.
[0012] Preferably, the long-chain olefins can be selected from one or more of 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 1-docoenic acid, and the like.
[0013] In the above scheme, the quaternary ammonium salt group is introduced by reacting the thiol group of the thiol-modified carbon sphere with a quaternary ammonium salt having a double bond.
[0014] Furthermore, the quaternary ammonium salt with a double bond can be selected from one or more of methacryloyloxyethyl trimethyl ammonium chloride, allyl trimethyl ammonium chloride, benzyl vinyl trimethyl ammonium chloride, (3-acrylamidopropyl) trimethyl ammonium chloride, 1-vinyl-3-methyl-1H-imidazole chloride, and the like.
[0015] In the above scheme, the solvent thermal reaction temperature is 80-130°C and the time is 10-24h.
[0016] The preparation method of the Janus carbon ball demulsifier specifically comprises the following steps:
[0017] 1) Preparation of thiol-modified carbon spheres;
[0018] Glucose is dissolved in water and subjected to a hydrothermal reaction to prepare carbon spheres; the obtained carbon spheres, a thiol modifier and a catalyst are then dispersed in an organic solvent I and subjected to a solvothermal reaction to obtain thiol-modified carbon spheres;
[0019] 2) preparing paraffin composite microspheres;
[0020] The thiol-modified carbon spheres are dispersed in water, added to melted paraffin, treated with a high-speed homogenizer, and cooled to room temperature to obtain paraffin composite microspheres with the surface covered with thiol-modified carbon spheres;
[0021] 3) Unilateral hydrophobic modification;
[0022] The obtained paraffin composite microspheres are dispersed in organic solvent II, long-chain olefins and photoinitiators are added, and the reaction is carried out at room temperature under ultraviolet light; the paraffin is then removed with organic solvent III to obtain unilaterally hydrophobically modified carbon spheres;
[0023] 4) Unilateral quaternary ammonium salt modification;
[0024] The obtained unilaterally hydrophobically modified carbon spheres are added to an organic solvent II, and after being evenly dispersed, a quaternary ammonium salt with a double bond and a photoinitiator are added, and then reacted at room temperature under ultraviolet light to obtain the Janus carbon sphere demulsifier.
[0025] In the above scheme, the temperature of the hydrothermal reaction in step 1) is 150-200° C. and the time is 12-24 h; the temperature of the solvothermal reaction is 80-130° C. and the time is 10-24 h.
[0026] Preferably, the mass ratio of glucose to water is 1:(7-15).
[0027] Preferably, the mass ratio of the carbon spheres to the thiol modifier is 1:(2-5).
[0028] Preferably, the catalyst is one or more of p-toluenesulfonic acid, trifluoromethanesulfonic acid, and methanesulfonic acid.
[0029] Preferably, the amount of the catalyst added is 0.5-5% of the total mass of the reactants.
[0030] Preferably, the organic solvent I can be selected from one or more of dioxane, toluene, xylene, etc.
[0031] Preferably, in step 2), the mass ratio of the thiol-modified carbon spheres, water and paraffin is 1:(10-20):(1-3).
[0032] Preferably, the paraffin wax is solid paraffin wax with a melting point below 60°C.
[0033] Preferably, the high-speed homogenizer is used at a rotation speed of 11000-23000 rpm and a processing time of 20-50 min.
[0034] Preferably, the mass ratio of the paraffin composite microspheres to the long-chain olefin in step 3) is 1:(2-5).
[0035] Preferably, the photoinitiator is one or more of 1-hydroxycyclohexyl benzophenone, 2-hydroxy-2-methyl-1-phenylpropanone, methyl benzoylformate, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2-dimethylamino-2-benzyl-1-[4-(4-morpholinyl)phenyl]-1-butanone, and the like.
[0036] Preferably, the amount of the photoinitiator added is 0.5-5% of the total mass of the reactants.
[0037] Preferably, the organic solvent II can be selected from one or more of methanol, ethanol, acetone, etc.
[0038] Preferably, the organic solvent III can be selected from one or more of gasoline, carbon disulfide, xylene, ether, benzene, chloroform, carbon tetrachloride, naphtha, etc.
[0039] Preferably, the mass ratio of the unilaterally hydrophobically modified carbon spheres to the quaternary ammonium salt with double bonds is 1:(1-2).
[0040] In the above scheme, the reaction time at room temperature in step 3) and step 4) is 1-5 hours.
[0041] The present invention also provides an application of a Janus carbon sphere demulsifier in demulsifying a crude oil emulsion (water-in-oil emulsion), comprising the following steps: dispersing the Janus carbon sphere demulsifier in a solvent IV to obtain a dispersion, and then mixing the dispersion with the crude oil emulsion at 40-70° C. and standing for 0.5-3 hours.
[0042] In the above solution, the solvent may be one or more selected from water, ethanol, xylene, etc.; the mass fraction of the Janus carbon sphere demulsifier in the dispersion is 0.2-1 wt%.
[0043] In the above solution, the volume ratio of the dispersion liquid to the crude oil emulsion is 1:10-20.
[0044] In the above scheme, the concentration of the Janus carbon sphere demulsifier in the mixed solution obtained by the dispersion and the crude oil emulsion is 200-500 mg / L.
[0045] Compared with the prior art, the present invention has the following beneficial effects:
[0046] 1) The Janus carbon sphere demulsifier of the present invention first uses glucose as a raw material to prepare carbon nanospheres, then performs surface thiol modification, and then grafts different groups on different sides of the carbon nanospheres, with a hydrophobic long alkyl chain grafted on one side and a hydrophilic and positively charged quaternary ammonium salt grafted on the other side, to form a Janus structure; the obtained Janus carbon sphere demulsifier can be directionally adsorbed at the oil-water interface, has amphiphilicity and excellent interfacial activity, and can significantly reduce the oil-water interfacial tension.
[0047] 2) In the Janus carbon sphere demulsifier provided by the present invention, the surface-grafted hydrophobic long alkyl chain and the π conjugated system of the carbon nanosphere itself enable it to undergo n-π interaction, π-π interaction and hydrophobic interaction with asphaltene, etc., replacing the original asphaltene on the interfacial film to form a Janus carbon sphere film with lower stability or directly destroying the interfacial film, causing the water phase to aggregate and induce demulsification. The quaternary ammonium salt at the hydrophilic end of the Janus carbon sphere demulsifier is positively charged and can undergo electrostatic neutralization with the negatively charged interfacial film, enhancing the adsorption of Janus carbon spheres and asphaltene, weakening the interfacial film strength, and further effectively promoting demulsification. In addition, the resulting composite demulsifier is an organically modified inorganic nanoparticle. The inorganic-organic composite can enhance the chemical stability and thermal stability of the demulsifier and is suitable for complex application environments; and the long-chain alkyl grafted carbon nanospheres can make the carbon nanospheres have better dispersibility and rapid diffusion ability in the oil phase.
[0048] 3) The Janus carbon sphere demulsifier described in the present invention is solid and insoluble in water and oil phases, and can be separated by gravity sedimentation filtration and other methods; its main component is bio-based carbon spheres, which have good economic and environmental benefits; and the preparation method involved is relatively simple, the reaction conditions are mild, and the cycle is short, making it suitable for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS
[0049] Figure 1 The synthetic flow chart of the Janus carbon sphere demulsifier described in one embodiment is as follows;
[0050] Figure 2 Schematic diagram of the structure of the Janus carbon ball demulsifier prepared in Example 1. DETAILED DESCRIPTION
[0051] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0052] Example 1
[0053] A Janus carbon sphere demulsifier, the preparation method of which comprises the following steps:
[0054] 1) 3 g of glucose was dissolved in 30 g of water and reacted at 180° C. for 18 h to obtain carbon spheres. Then, 3 g of carbon spheres, 6 g of thioglycolic acid, and 0.05 g of p-toluenesulfonic acid were dispersed in a mixed solvent of 20 ml of dioxane and 10 ml of xylene, and reacted at 120° C. for 12 h to obtain thiol-modified carbon spheres.
[0055] 2) 3 g of thiol-modified carbon spheres were dispersed in 30 g of water, heated to 75°C, and then added to 3 g of paraffin wax melted at 75°C. The mixture was homogenized with a high-speed homogenizer (11,000 rpm for 30 min) and cooled to room temperature to obtain paraffin wax microspheres covered with carbon spheres.
[0056] 3) Dispersing 3 g of paraffin microspheres in 20 mL of methanol, adding 6 g of 1-dodecene and 0.05 g of 1-hydroxycyclohexyl benzophenone, and reacting at room temperature for 2 h under ultraviolet light; removing the paraffin with chloroform to obtain unilaterally hydrophobically modified carbon spheres;
[0057] 4) 3 g of unilaterally hydrophobically modified carbon spheres were added to 20 mL of methanol, and after uniform dispersion, 6 g of allyltrimethylammonium chloride and 0.05 g of 1-hydroxycyclohexyl benzophenone were added. The mixture was reacted at room temperature under ultraviolet light for 2 h to obtain a Janus carbon sphere demulsifier.
[0058] Example 2
[0059] A Janus carbon sphere demulsifier, the preparation method of which comprises the following steps:
[0060] 1) 3 g of glucose was dissolved in 30 g of water and reacted at 180° C. for 18 h to obtain carbon spheres. Then, 3 g of carbon spheres, 6 g of thioglycolic acid, and 0.05 g of p-toluenesulfonic acid were dispersed in a mixed solvent of 20 ml of dioxane and 10 ml of xylene, and reacted at 120° C. for 12 h to obtain thiol-modified carbon spheres.
[0061] 2) 3 g of thiol-modified carbon spheres were dispersed in 30 g of water, heated to 75°C, and then added to 3 g of paraffin wax melted at 75°C. The mixture was homogenized with a high-speed homogenizer (11,000 rpm for 30 min) and cooled to room temperature to obtain paraffin wax microspheres covered with carbon spheres.
[0062] 3) 3 g of paraffin microspheres were dispersed in 20 mL of methanol, and 6 g of 1-hexadecene and 0.05 g of 1-hydroxycyclohexylbenzophenone were added. The mixture was reacted at room temperature under ultraviolet light for 2 h, and then treated with chloroform to remove the paraffin, thereby obtaining unilaterally hydrophobically modified carbon spheres.
[0063] 4) 3 g of unilaterally hydrophobically modified carbon spheres were added to 20 mL of methanol, and after uniform dispersion, 6 g of allyltrimethylammonium chloride and 0.05 g of 1-hydroxycyclohexyl benzophenone were added. The mixture was reacted at room temperature under ultraviolet light for 2 h to obtain a Janus carbon sphere demulsifier.
[0064] Example 3
[0065] A Janus carbon sphere demulsifier, the preparation method of which comprises the following steps:
[0066] 1) 3 g of glucose was dissolved in 30 g of water and reacted at 180°C for 18 h to obtain carbon spheres. Then, 3 g of carbon spheres, 6 g of thioglycolic acid, and 0.05 g of p-toluenesulfonic acid were dispersed in a mixed solvent of 20 mL of dioxane and 10 mL of xylene, and reacted at 120°C for 12 h to obtain thiol-modified carbon spheres.
[0067] 2) 3 g of thiol-modified carbon spheres were dispersed in 30 g of water, heated to 75°C, and then added to 3 g of paraffin wax melted at 75°C. The mixture was homogenized at 11,000 rpm for 30 min and then cooled to room temperature to obtain paraffin wax microspheres covered with carbon spheres.
[0068] 3) 3 g of paraffin microspheres were dispersed in 20 mL of methanol, and 6 g of 1-eicosene and 0.05 g of 1-hydroxycyclohexylbenzophenone were added. The mixture was reacted at room temperature under ultraviolet light for 2 h, and then treated with chloroform to remove the paraffin, thereby obtaining unilaterally hydrophobically modified carbon spheres.
[0069] 4) 3 g of unilaterally hydrophobically modified carbon spheres were added to 20 mL of methanol, and after uniform dispersion, 6 g of allyltrimethylammonium chloride and 0.05 g of 1-hydroxycyclohexyl benzophenone were added. The mixture was reacted at room temperature under ultraviolet light for 2 h to obtain a Janus carbon sphere demulsifier.
[0070] Comparative Example 1
[0071] A carbon ball demulsifier, the preparation method of which comprises the following steps:
[0072] 3g of glucose was dissolved in 30g of water and reacted at 180°C for 18h to obtain carbon spheres. 3g of carbon spheres, 6g of thioglycolic acid, and 0.05g of p-toluenesulfonic acid were then dispersed in a mixed solvent of 20mL of dioxane and 10mL of xylene and reacted at 120°C for 12h to obtain thiol-modified carbon spheres. 3g of thiol-modified carbon spheres were dispersed in 20mL of methanol, 6g of 1-dodecene and 0.05g of 1-hydroxycyclohexylbenzophenone were added, and the mixture was reacted at room temperature under ultraviolet light for 2h. After treatment with chloroform to remove the paraffin, a hydrophobically modified carbon sphere demulsifier was obtained.
[0073] Comparative Example 2
[0074] A carbon ball demulsifier, the preparation method of which comprises the following steps:
[0075] 3g of glucose was dissolved in 30g of water and reacted at 180°C for 18h to obtain carbon spheres. 3g of carbon spheres, 6g of thioglycolic acid, and 0.05g of p-toluenesulfonic acid were then dispersed in a mixed solvent of 20mL of dioxane and 10mL of xylene and reacted at 120°C for 12h to obtain thiol-modified carbon spheres. 3g of thiol-modified carbon spheres were added to 20mL of methanol and uniformly dispersed. 6g of allyltrimethylammonium chloride and 0.05g of 1-hydroxycyclohexyl benzophenone were then added and reacted at room temperature under ultraviolet light for 2h to obtain a quaternary ammonium salt-modified carbon sphere demulsifier.
[0076] Comparative Example 3
[0077] A carbon ball demulsifier, the preparation method of which comprises the following steps:
[0078] 3g of glucose was dissolved in 30g of water and reacted at 180°C for 18h to obtain carbon spheres. 3g of carbon spheres, 6g of thioglycolic acid, and 0.05g of p-toluenesulfonic acid were then dispersed in a mixed solvent of 20mL of dioxane and 10mL of xylene and reacted at 120°C for 12h to obtain thiol-modified carbon spheres. 3g of thiol-modified carbon spheres were added to 20mL of methanol and uniformly dispersed. 6g of 1-dodecene, 6g of allyltrimethylammonium chloride, and 0.05g of 1-hydroxycyclohexyl benzophenone were then added and reacted at room temperature under ultraviolet light for 2h to obtain an amphiphilic carbon sphere demulsifier.
[0079] Comparative Example 4
[0080] A Janus carbon sphere demulsifier, the preparation method of which comprises the following steps:
[0081] 1) 3 g of glucose was dissolved in 30 g of water and reacted at 180° C. for 18 h to obtain carbon spheres. Then, 3 g of carbon spheres, 6 g of thioglycolic acid, and 0.05 g of p-toluenesulfonic acid were dispersed in a mixed solvent of 20 ml of dioxane and 10 ml of xylene, and reacted at 120° C. for 12 h to obtain thiol-modified carbon spheres.
[0082] 2) 3 g of thiol-modified carbon spheres were dispersed in 30 g of water, heated to 75°C, and then added to 3 g of paraffin wax melted at 75°C. The mixture was homogenized with a high-speed homogenizer (11,000 rpm for 30 min) and cooled to room temperature to obtain paraffin wax microspheres covered with carbon spheres.
[0083] 3) 3 g of paraffin microspheres were dispersed in 20 mL of methanol, and 6 g of 1-dodecene and 0.05 g of 1-hydroxycyclohexyl benzophenone were added. The mixture was reacted at room temperature under ultraviolet light for 2 h. The paraffin was removed by treatment with chloroform to obtain unilaterally hydrophobically modified carbon spheres.
[0084] Comparative Example 5
[0085] A Janus carbon sphere demulsifier, the preparation method of which comprises the following steps:
[0086] 1) 3 g of glucose was dissolved in 30 g of water and reacted at 180° C. for 18 h to obtain carbon spheres. Then, 3 g of carbon spheres, 6 g of thioglycolic acid, and 0.05 g of p-toluenesulfonic acid were dispersed in a mixed solvent of 20 ml of dioxane and 10 ml of xylene, and reacted at 120° C. for 12 h to obtain thiol-modified carbon spheres.
[0087] 2) 3 g of thiol-modified carbon spheres were dispersed in 30 g of water, heated to 75°C, and then added to 3 g of paraffin wax melted at 75°C. The mixture was homogenized with a high-speed homogenizer (11,000 rpm for 30 min) and cooled to room temperature to obtain paraffin wax microspheres covered with carbon spheres.
[0088] 3) 3 g of paraffin microspheres were dispersed in 20 mL of methanol. After uniform dispersion, 6 g of allyltrimethylammonium chloride and 0.05 g of 1-hydroxycyclohexyl benzophenone were added. The mixture was reacted at room temperature under ultraviolet light for 2 h. The paraffin was removed by treatment with chloroform to obtain unilateral quaternary ammonium salt-modified carbon spheres.
[0089] Comparative Example 6
[0090] A Janus microcrystalline cellulose demulsifier, the preparation method of which comprises the following steps:
[0091] 1) Dispersing 3 g of silica nanoparticles, 6 g of thioglycolic acid, and 0.05 g of p-toluenesulfonic acid in a mixed solvent of 20 ml of dioxane and 10 ml of xylene, and reacting at 120° C. for 12 h to obtain thiol-modified silica;
[0092] 2) 3 g of mercapto-modified silica was dispersed in 30 g of water, heated to 75° C., and then added to 3 g of paraffin wax melted at 75° C. The mixture was homogenized with a high-speed homogenizer (11,000 rpm for 30 min) and then cooled to room temperature to obtain paraffin wax microspheres covered with mercapto-modified silica.
[0093] 3) Dispersing 3 g of the obtained paraffin microspheres in 20 mL of methanol, adding 6 g of 1-dodecene and 0.05 g of 1-hydroxycyclohexyl benzophenone, and reacting at room temperature under ultraviolet light for 2 h; treating with chloroform to remove the paraffin, to obtain unilaterally hydrophobically modified silica;
[0094] 4) 3 g of unilaterally hydrophobically modified silica was added to 20 mL of methanol, and after uniform dispersion, 6 g of allyltrimethylammonium chloride and 0.05 g of 1-hydroxycyclohexyl benzophenone were added, and the mixture was reacted at room temperature under ultraviolet light for 2 h to obtain a Janus nanosilica demulsifier.
[0095] Application Examples
[0096] The demulsifiers prepared in Examples 1-3 and Comparative Examples 1-6 were used to characterize the demulsification performance of the Janus carbon sphere demulsifier in crude oil emulsion. The specific steps included:
[0097] 1) Add 150 parts by mass of crude oil to 350 parts by mass of water, heat to 70° C., and then stir at 11,000 rpm for 20 minutes. Repeat this process three times until a stable water-in-oil emulsion is obtained.
[0098] 2) adding the demulsifiers prepared in Examples 1-3 and Comparative Examples 1-6 to ethanol to prepare demulsifier dispersions with a mass fraction of 0.6%;
[0099] 3) 1 part by volume of the above demulsifier dispersion was added to 20 parts by volume of the water-in-oil emulsion and mixed evenly. The mixture was then transferred to a 60°C water bath and allowed to stand for 3 hours. The demulsification efficiency was characterized by measuring its dehydration rate (referring to the Petroleum and Natural Gas Industry Standard SY / T5281-2000 of the People's Republic of China). The results are shown in Table 1.
[0100] Table 1 Demulsification results of demulsifiers obtained from Examples 1 to 3 and Comparative Examples 1 to 6
[0101] serial number Demulsifier concentration (mg / L) Demulsification efficiency (%) Example 1 300 95.3 Example 2 300 93.8 Example 3 300 90.1 Comparative Example 1 300 78.4 Comparative Example 2 300 30.8 Comparative Example 3 300 82.3 Comparative Example 4 300 80.3 Comparative Example 5 300 11.5 Comparative Example 6 300 28.9
[0102] It can be seen from Table 1 that the Janus carbon sphere demulsifiers prepared in Examples 1-3 all have very good demulsification performance, and the demulsification efficiency of Example 1 is the highest.
[0103] The Janus carbon sphere demulsifier prepared in Example 1 was further used to characterize the demulsification performance of Janus carbon sphere demulsifiers with different concentrations in crude oil emulsions. The specific steps included:
[0104] 1) Add 150 parts by mass of crude oil to 350 parts by mass of water, heat to 70° C., and then stir at 11,000 rpm for 20 minutes. Repeat this process three times until a stable water-in-oil emulsion is obtained.
[0105] 2) Different weight portions of Janus carbon sphere demulsifier were added to ethanol to prepare demulsifier dispersions with mass fractions of 1%, 0.8%, 0.6%, 0.4%, and 0.2%, respectively. The obtained samples were recorded as experimental groups 1-5; the blank group was 0%, and the sample was recorded as experimental group 6;
[0106] 3) 1 part by volume of the Janus carbon sphere demulsifier dispersion was added to 20 parts by volume of the crude oil emulsion and mixed thoroughly. The mixture was then transferred to a 60°C water bath and allowed to stand for 3 hours. The demulsification efficiency was characterized by measuring its dehydration rate (referring to the Petroleum and Natural Gas Industry Standard SY / T5281-2000 of the People's Republic of China). The results are shown in Table 2.
[0107] Table 2 Demulsification results of Janus carbon ball demulsifier under different concentration conditions described in Example 1
[0108] Group Janus carbon ball demulsifier concentration (mg / L) Demulsification efficiency (%) Experimental Group 1 500 95.8 Experimental Group 2 400 95.5 Experimental Group 3 300 95.3 Experimental Group 4 200 87.6 Experimental Group 5 100 48.5 Experimental Group 6 0 0
[0109] As shown in Table 2, the Janus carbon sphere demulsifier provided by the present invention has good demulsification performance.
[0110] The Janus carbon sphere demulsifier provided by the present invention has different properties on its two surfaces: one side is grafted with a hydrophobic long chain, and the other side is grafted with a hydrophilic quaternary ammonium salt. The Janus carbon sphere demulsifier provided by the present invention is amphiphilic and has excellent surface and interfacial activity. It can significantly reduce oil-water interfacial tension, soften or destroy the oil-water interfacial film, and has good demulsification performance.
[0111] The present invention is not limited to the above-described embodiments. Persons skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are deemed to be within the scope of protection of the present invention. Any matters not described in detail in this specification constitute prior art known to those skilled in the art.
Claims
1. A Janus carbon ball demulsifier, characterized in that: The carbon sphere comprises a thiol-modified carbon sphere and long-chain alkyl hydrophobic groups and quaternary ammonium salt groups introduced on different surfaces of the carbon sphere.
2. The Janus carbon ball demulsifier according to claim 1, characterized in that The thiol-modified carbon spheres are obtained by dispersing bio-based carbon spheres, a thiol-modifying agent and a catalyst in an organic solvent and performing a solvothermal reaction.
3. The Janus carbon ball demulsifier according to claim 2, characterized in that The mercapto modifier is at least one of mercaptoacetic acid, mercaptopropionic acid, and mercaptobutyric acid.
4. The Janus carbon ball demulsifier according to claim 1, characterized in that The long-chain alkyl hydrophobic group is introduced by a click reaction between the thiol groups of the thiol-modified carbon spheres and the carbon-carbon double bonds in the long-chain olefins.
5. The Janus carbon ball demulsifier according to claim 2, characterized in that The long-chain olefin is an α-olefin, and the number of carbon atoms in the long chain is 12 or more.
6. The Janus carbon ball demulsifier according to claim 1, characterized in that The quaternary ammonium salt group is introduced by reacting the thiol group of the thiol-modified carbon sphere with a quaternary ammonium salt having a double bond.
7. The Janus carbon ball demulsifier according to claim 1, characterized in that The quaternary ammonium salt with a double bond is one or more of methacryloyloxyethyl trimethyl ammonium chloride, allyl trimethyl ammonium chloride, benzyl vinyl trimethyl ammonium chloride, (3-acrylamidopropyl) trimethyl ammonium chloride, and 1-vinyl-3-methyl-1H-imidazole chloride.
8. The method for preparing the Janus carbon sphere demulsifier according to any one of claims 1 to 7, characterized in that: The specific steps include: 1) Preparation of thiol-modified carbon spheres; Glucose is dissolved in water and subjected to a hydrothermal reaction to prepare carbon spheres; the obtained carbon spheres, a thiol modifier and a catalyst are then dispersed in an organic solvent I and subjected to a solvothermal reaction to obtain thiol-modified carbon spheres; 2) preparing paraffin composite microspheres; The thiol-modified carbon spheres are dispersed in water, added to melted paraffin, treated with a high-speed homogenizer, and cooled to room temperature to obtain paraffin composite microspheres with the surface covered with thiol-modified carbon spheres; 3) Unilateral hydrophobic modification; The obtained paraffin composite microspheres are dispersed in organic solvent II, long-chain olefins and photoinitiators are added, and the reaction is carried out at room temperature under ultraviolet light; the paraffin is then removed with organic solvent III to obtain unilaterally hydrophobically modified carbon spheres; 4) Unilateral quaternary ammonium salt modification; The obtained unilaterally hydrophobically modified carbon spheres are added to an organic solvent II, and after being evenly dispersed, a quaternary ammonium salt with a double bond and a photoinitiator are added, and then reacted at room temperature under ultraviolet light to obtain the Janus carbon sphere demulsifier.
9. The preparation method according to claim 8, characterized in that The solvent thermal reaction in step 1) is carried out at a temperature of 80-130° C. for 10-24 hours; and the room temperature reaction in steps 3) and 4) is carried out for 1-5 hours.
10. Application of a Janus carbon sphere demulsifier in demulsifying crude oil emulsion.