A method for preparing a demulsifier for a desulfurization system

Abstract

The present application relates to the technical field of demulsifiers, and specifically discloses a method for preparing a demulsifier for a desulfurization system. A method for preparing a demulsifier for a desulfurization system comprises the following steps: firstly preparing a polymer polyether, then making it undergo a cross-linking reaction, and finally adding a modified hollow porous silica tube and mixing evenly to obtain a demulsifier for a desulfurization system. The demulsifier for a desulfurization system prepared by the present application has the advantages of high dehydration rate and good demulsification effect.

Description

Technical Field

[0001] The present application relates to the technical field of demulsifiers, and more specifically, to a method for preparing a demulsifier for a desulfurization system. Background Art

[0002] As crude oil production enters the middle and late stages, the composition and characteristics of crude oil have undergone many changes, bringing about a series of subsequent problems. On the one hand, the content of colloids and asphaltene in crude oil has increased significantly. With their complex chemical structure and unique properties, they are adsorbed on the oil-water interface, just like strong adhesives, which greatly enhances the stability of crude oil emulsions and causes the viscosity of emulsified crude oil to increase sharply, which in turn leads to a significant increase in resistance during pipeline transportation, and the pumping cost has also increased significantly. On the other hand, the continuous innovation and widespread promotion of oil production technology have introduced a large number of surfactants for oil recovery, which has helped crude oil production, but has also made the composition of crude oil more complicated. These surfactants further stabilize the crude oil emulsification system, causing the water and salt content of crude oil produced from the oil field to increase.

[0003] When the extracted crude oil is used for production and life, it must go through multiple delicate processing steps because it contains a large amount of unqualified substances. Among them, desulfurization treatment is crucial, and before desulfurization treatment, the crude oil needs to be pre-treated by demulsification. This step can successfully separate the water phase and oil phase in the crude oil, so that during the subsequent desulfurization, the desulfurizer can directly contact the sulfide in the crude oil without hindrance, greatly improving the efficiency of the desulfurization reaction. At the same time, demulsification pretreatment can also remove most of the water and impurities in the crude oil, effectively reducing the corrosion and wear of these substances on desulfurization equipment, such as absorption towers, heat exchangers, etc., thereby extending the service life of the desulfurization equipment.

[0004] The Chinese patent application document with application publication number CN118460241A discloses a method for preparing a demulsifier. The demulsifier prepared in the patent application document uses a terminal sulfonate polyether and a modified BN / MgAl-LDHs composite material to work together to improve the demulsification efficiency of the demulsifier; wherein, the terminal sulfonate polyether utilizes electrostatic neutralization to weaken the mutual repulsion between water droplets adsorbed by positive ions, thereby improving the demulsification efficiency of the demulsifier and improving the high temperature resistance of the demulsifier; and the modified BN / MgAl-LDHs composite material utilizes its strong hydrophilic-lipophilic properties to reduce the interfacial tension of the emulsion, so that it quickly migrates to the oil-water interface and completes adsorption and aggregation, promoting the coalescence of dispersed phase droplets, and then achieving the demulsification effect. However, the BN / MgAl-LDHs composite material used in the application document is relatively expensive, which is not conducive to long-term development. Summary of the invention

[0005] In order to further improve the demulsification ability of a demulsifier for a desulfurization system, the present application provides a method for preparing a demulsifier for a desulfurization system.

[0006] The present application provides a method for preparing a demulsifier for a desulfurization system, which adopts the following technical scheme:

[0007] A method for preparing a demulsifier for a desulfurization system comprises the following steps:

[0008] (1) Mix bisphenol A and tetraethylenepentamine evenly, add formaldehyde aqueous solution, react for 2-3 hours, and vacuum rotary evaporate to obtain polymerization center;

[0009] (2) mixing the polymerization center and sodium hydroxide, adding propylene oxide to carry out a first stage polymerization reaction, and after the reaction is completed, adding potassium hydroxide and ethylene oxide to carry out a second stage polymerization reaction to obtain a high molecular weight polyether;

[0010] (3) Mix the polymer polyether and diphenyl dicarboxylic acid, stir and react for 1-1.5 hours, then add the modified hollow porous silica tube, mix evenly, and obtain a demulsifier for the desulfurization system;

[0011] The preparation method of the modified hollow porous silica tube comprises the following steps:

[0012] S1: Mix wollastonite, water and corundum, grind, filter and dry to obtain needle-shaped wollastonite;

[0013] S2: Mix needle-shaped wollastonite, ethanol and water evenly, add ammonia water to adjust the pH value, add dodecyltrimethylammonium bromide and ethyl orthosilicate, react by precipitation, filter, wash, calcine, cool and put into hydrochloric acid solution, soak, filter, wash and dry to obtain a hollow porous silica tube;

[0014] S3: Take the hollow porous silica tube and ethanol and mix them evenly, add γ-chloropropyltrimethoxysilane, heat to react, then add dodecyldimethyl tertiary amine to react, and after the reaction is completed, filter and dry to obtain a modified hollow porous silica tube.

[0015] By adopting the above technical scheme, the polymer polyether is cross-linked and modified by using biphenyl dicarboxylic acid, and the rigidity of the polymer polyether molecule is enhanced by introducing a benzene ring, while the affinity of the demulsifier and the natural emulsifier in the crude oil is improved, and the diffusion resistance of the demulsifier at the oil-water interface and the resistance of penetrating the interface film are reduced, thereby improving the demulsification efficiency; at the same time, quaternary ammonium hollow porous silica tubes are added to the demulsifier to destroy the interface film formed by the colloid and the asphaltene, and the high specific surface area of ​​the hollow porous silica tubes is utilized to promote the continuous aggregation of oil droplets and water droplets. As the aggregation proceeds, the oil droplets and water droplets continue to grow larger, and finally the oil-water separation is achieved, thereby effectively improving the demulsification efficiency.

[0016] Preferably, in step (1), the mass ratio of bisphenol A, tetraethylenepentamine and formaldehyde aqueous solution is 1:(2-2.4):(1.2-1.5).

[0017] By adopting the above technical solution, the molecular structure stability of the polymerization center is enhanced and it is not easy to decompose, so that the demulsifier maintains good demulsification performance.

[0018] Preferably, in step (2), the mass ratio of the polymerization center, propylene oxide and ethylene oxide is 1:(14.5-17):(6-7).

[0019] By adopting the above technical scheme, a high molecular weight polyether with a good branched structure is prepared, and its adsorption capacity at the oil-water interface is enhanced, replacing the natural emulsifier originally adsorbed on the oil-water interface, destroying the original stable oil-water interface film, reducing the stability of the emulsion, promoting the separation of the oil phase and the water phase, and thus improving the demulsification ability of the demulsifier.

[0020] Preferably, in step (2), the temperature of the first stage polymerization reaction is 110-120°C; and the temperature of the second stage polymerization reaction is 100-110°C.

[0021] By adopting the above technical scheme, the reaction between propylene oxide and the polymerization center can be efficiently initiated, and propylene oxide is evenly grafted on the polymerization center to form a moderate branched structure; at the same time, ethylene oxide is fully involved in the reaction, effectively reducing the oil-water interfacial tension, thereby promoting the aggregation of oil droplets and water droplets, and improving the demulsification efficiency of the demulsifier.

[0022] Preferably, in step (3), the mass ratio of the polymer polyether, the biphenyl dicarboxylic acid organic solution and the modified hollow porous silica tube is (9-11):(0.15-0.3):1.

[0023] By adopting the above technical scheme, the stability of the polymer polyether is improved, making it easier to adsorb on the oil-water interface, destroying the stability of the oil-water interface film, and reducing the oil-water interfacial tension to promote the coalescence of water droplets, thereby achieving oil-water separation. At the same time, the modified hollow porous silica tube provides a good bridge for the aggregation of emulsion droplets, effectively improving the demulsification efficiency.

[0024] Preferably, in step S1, the mass ratio of wollastonite, water and corundum is 1:(0.8-1.2):(2.5-3).

[0025] By adopting the above technical solution, wollastonite is evenly dispersed in the grinding system to avoid agglomeration, so that the wollastonite after grinding has a regular shape and uniform size. When participating in the generation of hollow porous silica tubes, the hollow porous silica tubes have a good morphological structure, which can interact with the oil phase and the water phase more effectively, thereby improving the demulsification efficiency.

[0026] Preferably, in step S1, the wollastonite is a needle-shaped powder with a size of 200-325 mesh.

[0027] By adopting the above technical scheme, needle-shaped wollastonite with a smaller particle size is prepared, so that the hollow porous silica tube has a smaller particle size and a larger specific surface area, thereby making the hollow porous silica tube have more active sites and improving its quaternization degree. At the same time, the higher specific surface area also promotes the continuous aggregation of oil droplets and water droplets, thereby making the demulsifier have good demulsification ability.

[0028] Preferably, in step S2, the mass ratio of needle-shaped wollastonite, ethanol, dodecyltrimethylammonium bromide and tetraethyl orthosilicate is 1:(1.2-1.6):(0.45-0.6):(0.7-0.8).

[0029] By adopting the above technical solution, needle-shaped wollastonite is used as a template to guide the growth of silica, so that the generated silica has a good morphology and structure, increases the specific surface area and porosity of silica, and can effectively adsorb the emulsifier on the oil-water interface, thereby destroying the stability of the emulsion, promoting oil-water separation, and achieving demulsification.

[0030] Preferably, in step S2, the temperature of the deposition reaction is 15-30° C. and the time is 6-8 hours.

[0031] By adopting the above technical solution, ethyl orthosilicate is uniformly hydrolyzed and polycondensed on the surface of needle-shaped wollastonite, so that the deposition of the generated silica on the needle-shaped wollastonite is more uniform and regular, thereby improving the stability of the hollow porous silica tube and avoiding rupture during use, maintaining its stability as a bridge between emulsion droplets, and prolonging the effect of the demulsifier.

[0032] Preferably, in step S3, the mass ratio of the hollow porous silica tube, γ-chloropropyltrimethoxysilane and dodecyldimethyl tertiary amine is 1:(1-1.4):(0.8-1.2).

[0033] By adopting the above technical scheme, the hollow porous silica tube has a higher degree of quaternization, which enhances the ability of the demulsifier to resist corrosion by chemical substances such as acids and alkalis. At the same time, the modified hollow porous silica tube can replace the emulsifier of the original emulsion through electrostatic attraction or chemical adsorption, thereby destroying the stability of the emulsion, thereby enabling the demulsifier to exert a good demulsification effect.

[0034] In summary, this application has the following beneficial effects:

[0035] 1. Introducing benzene rings into the demulsifier increases the rigidity of the demulsifier molecular weight, while improving the affinity between the demulsifier and the natural emulsifier in the crude oil, reducing the diffusion resistance of the demulsifier at the oil-water interface and the resistance to penetrating the interface membrane, thereby improving the dehydration efficiency.

[0036] 2. The hollow and porous silica tube has a high specific surface area, which increases the demulsification reaction area when participating in the demulsification reaction. At the same time, the silica tube can form a bridge between the emulsion droplets, making them close to each other and agglomerate. Multiple emulsion droplets are connected together through the silica tube. As the agglomeration proceeds, the oil droplets and water droplets continue to grow larger, and finally the oil and water separation is achieved, thereby effectively improving the demulsification efficiency.

[0037] 3. In the modified hollow porous silica tubes, the quaternary ammonium groups can be adsorbed on the oil-water interface, and electrostatically interact with the emulsifier molecules on the oil-water interface, destroying the colloidal membrane and thus the stability of the emulsion. In addition, the aggregation of water droplets is promoted by reducing the oil-water interfacial tension, and finally the oil-water separation is achieved, thereby improving the demulsification efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a relationship diagram among the usage of demulsifier for desulfurization system prepared in Example 1 of the present application, demulsification time and dehydration rate.

[0039] Figure 2 It is a schematic diagram of the demulsification capabilities of Examples 1-3, Comparative Example 1 and Comparative Example 2 of the present application at different temperatures. DETAILED DESCRIPTION

[0040] The present application is further described in detail below with reference to the embodiments.

[0041] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0042] Example 1

[0043] The preparation method of the demulsifier for the desulfurization system of this embodiment comprises the following steps:

[0044] (1) 50 g of bisphenol A and 100 g of tetraethylene pentamine were mixed evenly, the temperature was adjusted to 50°C, 60 g of a 37% formaldehyde aqueous solution was added dropwise at a rate of 3 mL / min, and the mixture was kept warm for 2 h after the addition was completed. The mixture was vacuum evaporated at 70°C for 10 min to obtain a polymerization center;

[0045] (2) 10 g of polymerization center and 1 g of sodium hydroxide were added to the reactor, replaced with nitrogen three times, the temperature was adjusted to 110°C, 145 g of propylene oxide was added at a rate of 4 mL / min, and after the addition was completed, the reaction was continued for 1.5 h, and then the temperature was lowered to 100°C, 0.8 g of potassium hydroxide was added, and 60 g of ethylene oxide was added at a rate of 2 mL / min. After the addition was completed, the reaction was continued for 1 h to obtain a high molecular weight polyether;

[0046] (3) 90 g of high molecular weight polyether and 50 g of 3% by mass concentration of biphenyl dicarboxylic acid ethanol solution were mixed, the temperature was raised to 50° C., and the mixture was stirred for reaction for 1 h. Then 10 g of modified hollow porous silica tube was added and mixed evenly to obtain a demulsifier for a desulfurization system.

[0047] The preparation method of the modified hollow porous silica tube of this embodiment is as follows:

[0048] S1: 100g of 325 mesh wollastonite and 80g of water were put into a medium stirred mill, and corundum with a diameter of 0.8mm was used as the grinding medium. The amount of corundum added was 250g. The grinding was performed for 90min, filtered, dried, and passed through a 400 mesh sieve to obtain needle-shaped wollastonite;

[0049] S2: Take 20g of needle-shaped wollastonite, 24g of ethanol and 5g of water, mix them, ultrasonically disperse them for 20min, adjust the temperature to 15°C, add ammonia water to adjust the pH to 8, add 9g of hexadecyltrimethylammonium bromide, stir for 30min, add 14g of ethyl orthosilicate at a rate of 5mL / min, continue to react for 8h after the addition, stop stirring after the reaction, age at room temperature for 1h, filter, wash, dry at 40°C for 10h, then heat to 750°C at a rate of 1°C / min, calcine for 5h, cool, put into a hydrochloric acid solution with a mass percentage concentration of 20%, soak for 15h, filter, wash, and dry to obtain a hollow porous silica tube;

[0050] S3: Take 10g of hollow porous silica tube, 50g of ethanol and 20g of water and mix them evenly, heat to 90°C, add 10g of γ-chloropropyltrimethoxysilane, stir and react for 6h, then add 8g of dodecyldimethyl tertiary amine, stir and react for 4h, filter and dry to obtain modified hollow porous silica tube.

[0051] Example 2

[0052] The preparation method of the demulsifier for the desulfurization system of this embodiment comprises the following steps:

[0053] (1) 50 g of bisphenol A and 120 g of tetraethylene pentamine were mixed evenly, the temperature was adjusted to 55°C, and 75 g of a 37% formaldehyde aqueous solution was added dropwise at a rate of 3 mL / min. After the addition was completed, the mixture was kept warm for 3 h, and vacuum rotary evaporated at 70°C for 10 min to obtain a polymerization center;

[0054] (2) 10 g of polymerization center and 1 g of sodium hydroxide were added to the reactor, nitrogen was replaced three times, the temperature was adjusted to 120°C, 170 g of propylene oxide was added at a rate of 4 mL / min, and after the addition was completed, the reaction was continued for 1.5 h, and then the temperature was lowered to 110°C, 0.8 g of potassium hydroxide was added, and 70 g of ethylene oxide was added at a rate of 2 mL / min. After the addition was completed, the reaction was continued for 1 h to obtain a high molecular weight polyether;

[0055] (3) 110 g of high molecular weight polyether and 50 g of 6% by mass concentration of biphenyl dicarboxylic acid ethanol solution were mixed, the temperature was raised to 50° C., and the mixture was stirred for reaction for 1.5 h. Then 10 g of modified hollow porous silica tube was added and mixed evenly to obtain a demulsifier for a desulfurization system;

[0056] The preparation method of the modified hollow porous silica tube of this embodiment is as follows:

[0057] S1: 100g of 200-mesh wollastonite and 120g of water were put into a medium stirred mill, and 1mm-diameter corundum was used as the grinding medium. The amount of corundum added was 300g. The grinding was performed for 90min, filtered, dried, and passed through a 400-mesh sieve to obtain needle-shaped wollastonite;

[0058] S2: Take 20g of needle-shaped wollastonite, 32g of ethanol and 6g of water, mix them, ultrasonically disperse them for 20min, adjust the temperature to 30°C, add ammonia water to adjust the pH to 9, add 12g of hexadecyltrimethylammonium bromide, stir for 30min, add 16g of ethyl orthosilicate at a rate of 5mL / min, continue to react for 6h after the addition, stop stirring after the reaction, age at room temperature for 1h, filter, wash, dry at 40°C for 10h, then heat to 700°C at a rate of 1°C / min, calcine for 5h, cool, put into a hydrochloric acid solution with a mass percentage concentration of 30%, soak for 10h, filter, wash, and dry to obtain a hollow porous silica tube;

[0059] S3: Take 10g of hollow porous silica tube, 50g of ethanol and 20g of water and mix them evenly, heat to 90°C, add 14g of γ-chloropropyltrimethoxysilane, stir and react for 6h, then add 12g of dodecyldimethyl tertiary amine, stir and react for 4h, filter and dry to obtain modified hollow porous silica tube.

[0060] Example 3

[0061] The preparation method of the demulsifier for the desulfurization system of this embodiment comprises the following steps:

[0062] (1) 50 g of bisphenol A and 110 g of tetraethylene pentamine were mixed evenly, the temperature was adjusted to 50°C, and 65 g of a 37% formaldehyde aqueous solution was added dropwise at a rate of 3 mL / min. After the addition was completed, the mixture was kept warm for 2.5 h, and vacuum evaporated at 70°C for 10 min to obtain a polymerization center;

[0063] (2) 10 g of polymerization center and 1 g of sodium hydroxide were added to the reactor, nitrogen was replaced three times, the temperature was adjusted to 113 ° C, 150 g of propylene oxide was added at a rate of 4 mL / min, and after the addition was completed, the reaction was continued for 1.5 h, and then the temperature was lowered to 105 ° C, 0.8 g of potassium hydroxide was added, and 62 g of ethylene oxide was added at a rate of 2 mL / min. After the addition was completed, the reaction was continued for 1 h to obtain a high molecular weight polyether;

[0064] (3) 108 g of high molecular weight polyether and 50 g of 5% by mass concentration of biphenyl dicarboxylic acid ethanol solution were mixed, the temperature was raised to 50°C, and the mixture was stirred for reaction for 1 h. Then 10 g of modified hollow porous silica tube was added and mixed evenly to obtain a demulsifier for a desulfurization system.

[0065] The preparation method of the modified hollow porous silica tube of this embodiment is as follows:

[0066] S1: 100g of 250-mesh wollastonite and 90g of water were put into a medium stirred mill, and corundum with a diameter of 0.8mm was used as the grinding medium. The amount of corundum added was 260g. The grinding was performed for 90min, filtered, dried, and passed through a 400-mesh sieve to obtain needle-shaped wollastonite;

[0067] S2: Take 20g of needle-shaped wollastonite, 25g of ethanol and 5g of water, mix them, ultrasonically disperse them for 20min, adjust the temperature to 20°C, add ammonia water to adjust the pH to 8.5, add 10g of hexadecyltrimethylammonium bromide, stir for 30min, add 15g of ethyl orthosilicate at a rate of 5mL / min, continue to react for 7h after the addition, stop stirring after the reaction, age at room temperature for 1h, filter, wash, dry at 40°C for 10h, then heat to 700°C at a rate of 1°C / min, calcine for 5h, cool, put into a hydrochloric acid solution with a mass percentage concentration of 20%, soak for 15h, filter, wash, and dry to obtain a hollow porous silica tube;

[0068] S3: Take 10g of hollow porous silica tube, 50g of ethanol and 20g of water and mix them evenly, heat to 90°C, add 11g of γ-chloropropyltrimethoxysilane, stir and react for 6h, then add 10g of dodecyldimethyl tertiary amine, stir and react for 4h, filter and dry to obtain modified hollow porous silica tube.

[0069] Comparative Example 1

[0070] The preparation method of the demulsifier for the desulfurization system of this comparative example comprises the following steps:

[0071] (1) 50 g of bisphenol A and 100 g of tetraethylene pentamine were mixed evenly, the temperature was adjusted to 50°C, 60 g of a 37% formaldehyde aqueous solution was added dropwise at a rate of 3 mL / min, and the mixture was kept warm for 2 h after the addition was completed. The mixture was vacuum evaporated at 70°C for 10 min to obtain a polymerization center;

[0072] (2) 10 g of polymerization center and 1 g of sodium hydroxide were added to the reactor, replaced with nitrogen three times, the temperature was adjusted to 110°C, 145 g of propylene oxide was added at a rate of 4 mL / min, and after the addition was completed, the reaction was continued for 1.5 h, and then the temperature was lowered to 100°C, 0.8 g of potassium hydroxide was added, and 60 g of ethylene oxide was added at a rate of 2 mL / min. After the addition was completed, the reaction was continued for 1 h to obtain a high molecular weight polyether;

[0073] (3) 90 g of high molecular weight polyether, 50 g of ethanol and 10 g of modified hollow porous silica tube were mixed evenly to obtain a demulsifier for a desulfurization system;

[0074] The preparation method of the modified hollow porous silica tube of this comparative example is as follows:

[0075] S1: 100g of 325 mesh wollastonite and 80g of water were put into a medium stirred mill, and corundum with a diameter of 0.8mm was used as the grinding medium. The amount of corundum added was 250g. The grinding was performed for 90min, filtered, dried, and passed through a 400 mesh sieve to obtain needle-shaped wollastonite;

[0076] S2: Take 20g of needle-shaped wollastonite, 24g of ethanol and 5g of water, mix them, ultrasonically disperse them for 20min, adjust the temperature to 15°C, add ammonia water to adjust the pH to 8, add 9g of hexadecyltrimethylammonium bromide, stir for 30min, add 14g of ethyl orthosilicate at a rate of 5mL / min, continue to react for 8h after the addition, stop stirring after the reaction, age at room temperature for 1h, filter, wash, dry at 40°C for 10h, then heat to 750°C at a rate of 1°C / min, calcine for 5h, cool, put into a hydrochloric acid solution with a mass percentage concentration of 20%, soak for 15h, filter, wash, and dry to obtain a hollow porous silica tube;

[0077] S3: Take 10g of hollow porous silica tube, 50g of ethanol and 20g of water and mix them evenly, heat to 90°C, add 10g of γ-chloropropyltrimethoxysilane, stir and react for 6h, then add 8g of dodecyldimethyl tertiary amine, stir and react for 4h, filter and dry to obtain modified hollow porous silica tube.

[0078] Comparative Example 2

[0079] The preparation method of the demulsifier for the desulfurization system of this comparative example comprises the following steps:

[0080] (1) 50 g of bisphenol A and 100 g of tetraethylene pentamine were mixed evenly, the temperature was adjusted to 50°C, 60 g of a 37% formaldehyde aqueous solution was added dropwise at a rate of 3 mL / min, and the mixture was kept warm for 2 h after the addition was completed. The mixture was vacuum evaporated at 70°C for 10 min to obtain a polymerization center;

[0081] (2) 10 g of polymerization center and 1 g of sodium hydroxide were added to the reactor, replaced with nitrogen three times, the temperature was adjusted to 110°C, 145 g of propylene oxide was added at a rate of 4 mL / min, and after the addition was completed, the reaction was continued for 1.5 h, and then the temperature was lowered to 100°C, 0.8 g of potassium hydroxide was added, and 60 g of ethylene oxide was added at a rate of 2 mL / min. After the addition was completed, the reaction was continued for 1 h to obtain a high molecular weight polyether;

[0082] (3) Mix 90g of high molecular weight polyether and 50g of 3% by mass concentration of biphenyl dicarboxylic acid ethanol solution, heat to 50°C, stir and react for 1h, then add 10g of hollow porous silica tube, mix well, and obtain a demulsifier for desulfurization system;

[0083] The preparation method of the hollow porous silica tube of this comparative example is as follows:

[0084] S1: 100g of 325 mesh wollastonite and 80g of water were put into a medium stirred mill, and corundum with a diameter of 0.8mm was used as the grinding medium. The amount of corundum added was 250g. The grinding was performed for 90min, filtered, dried, and passed through a 400 mesh sieve to obtain needle-shaped wollastonite;

[0085] S2: Take 20g of needle-shaped wollastonite, 24g of ethanol and 5g of water, mix them, ultrasonically disperse them for 20min, adjust the temperature to 15℃, add ammonia water to adjust the pH to 8, add 9g of hexadecyltrimethylammonium bromide, stir for 30min, add 14g of tetraethyl orthosilicate at a rate of 5mL / min, continue to react for 8h after the addition is completed, stop stirring after the reaction is completed, age at room temperature for 1h, filter, wash, dry at 40℃ for 10h, then heat to 750℃ at a rate of 1℃ / min, calcine for 5h, cool, put into a hydrochloric acid solution with a mass percentage concentration of 20%, soak for 15h, filter, wash and dry to obtain a hollow porous silica tube.

[0086] Performance testing

[0087] 1. Preparation of simulated crude oil emulsion: Take 40g of dehydrated solid crude oil from Jiangsu Oilfield, melt it completely in a 45°C water bath, add 30g of odorless kerosene and stir to mix evenly, add 30g of water, stir for 20min at 3000rpm using a high shear emulsifier to prepare a simulated crude oil emulsion.

[0088] 2. Add 60 mL of simulated crude oil emulsion to a 100 mL colorimetric tube, place it in a 65°C constant temperature water bath and heat it for 20 minutes, then add the demulsifier for the desulfurization system, shake it by hand 200 times, continue to place it in a 65°C constant temperature water bath to stand and demulsify, and calculate the dehydration rate based on the volume of the dehydrated water.

[0089] Take the demulsifier for desulfurization system prepared in Example 1 to explore the relationship between the amount of demulsifier added, demulsification time and dehydration rate. Figure 1 shown.

[0090] When the demulsifier addition amount for the desulfurization system is 500ppm and the demulsification time is 100min, the demulsification performances of Examples 1-3, Comparative Examples 1 and 2 at different temperatures are as follows: Figure 2 shown.

[0091] Analyze Examples 1-3, Comparative Example 1 and Comparative Example 2 and combine Figure 1-2 It can be seen that cross-linking the polymer polyether and adding the modified hollow porous silica tube to the demulsifier used in the desulfurization system is beneficial to improving the demulsification ability of the demulsifier used in the desulfurization system.

[0092] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing a demulsifier for a desulfurization system, characterized in that: The steps include: (1) Mix bisphenol A and tetraethylenepentamine evenly, add formaldehyde aqueous solution, react for 2-3 hours, and vacuum rotary evaporate to obtain polymerization center; (2) mixing the polymerization center and sodium hydroxide, adding propylene oxide to carry out a first stage polymerization reaction, and after the reaction is completed, adding potassium hydroxide and ethylene oxide to carry out a second stage polymerization reaction to obtain a high molecular weight polyether; (3) Mix the polymer polyether and diphenyl dicarboxylic acid, stir and react for 1-1.5 hours, then add the modified hollow porous silica tube, mix evenly, and obtain a demulsifier for the desulfurization system; The preparation method of the modified hollow porous silica tube comprises the following steps: S1: Mix wollastonite, water and corundum, grind, filter and dry to obtain needle-shaped wollastonite; S2: Mix needle-shaped wollastonite, ethanol and water evenly, add ammonia water to adjust the pH value, add dodecyltrimethylammonium bromide and ethyl orthosilicate, react by precipitation, filter, wash, calcine, cool and put into hydrochloric acid solution, soak, filter, wash and dry to obtain a hollow porous silica tube; S3: Take the hollow porous silica tube and ethanol and mix them evenly, add γ-chloropropyltrimethoxysilane, heat to react, then add dodecyldimethyl tertiary amine to react, and after the reaction is completed, filter and dry to obtain a modified hollow porous silica tube.

2. The method for preparing a demulsifier for a desulfurization system according to claim 1, characterized in that: In the step (1), the mass ratio of bisphenol A, tetraethylenepentamine and formaldehyde aqueous solution is 1:(2-2.4):(1.2-1.5).

3. The method for preparing a demulsifier for a desulfurization system according to claim 1, characterized in that: In the step (2), the mass ratio of the polymerization center, propylene oxide and ethylene oxide is 1:(14.5-17):(6-7).

4. The method for preparing a demulsifier for a desulfurization system according to claim 1, characterized in that: In the step (2), the temperature of the first stage polymerization reaction is 110-120°C; the temperature of the second stage polymerization reaction is 100-110°C.

5. The method for preparing a demulsifier for a desulfurization system according to claim 1, characterized in that: In the step (3), the mass ratio of the polymer polyether, biphenyl dicarboxylic acid and the modified hollow porous silica tube is (9-11):(0.15-0.3):

1.

6. The method for preparing a demulsifier for a desulfurization system according to claim 1, characterized in that: In the step S1, the mass ratio of wollastonite, water and corundum is 1:(0.8-1.2):(2.5-3).

7. The method for preparing a demulsifier for a desulfurization system according to claim 1, characterized in that: In the step S1, the wollastonite is a needle-shaped powder with a size of 200-325 mesh.

8. The method for preparing a demulsifier for a desulfurization system according to claim 1, characterized in that: In the step S2, the mass ratio of needle-shaped wollastonite, ethanol, dodecyltrimethylammonium bromide and tetraethyl orthosilicate is 1:(1.2-1.6):(0.45-0.6):(0.7-0.8).

9. The method for preparing a demulsifier for a desulfurization system according to claim 1, characterized in that: In step S2, the deposition reaction temperature is 15-30° C. and the time is 6-8 hours.

10. The method for preparing a demulsifier for a desulfurization system according to claim 1, characterized in that: In the step S3, the mass ratio of the hollow porous silica tube, γ-chloropropyltrimethoxysilane and dodecyldimethyl tertiary amine is 1:(1-1.4):(0.8-1.2).

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