Demetallizing agents, methods of making and using same, and use of demetallizing adjuvants

Abstract

The application discloses a demetallization agent, a preparation method and application method thereof, and a use of a demetallization auxiliary agent. The demetallization agent comprises a core-shell structure, is composed of an organic material with a chelating functional group, and comprises a core and a shell layer. The core is a sub-micron organic polymer particle, and the shell layer is an amphiphilic polymer with a functional group of strong electrostatic adsorption and metal chelating capacity connected to the surface. The preparation method of the demetallization agent comprises the steps of initiating connection and preparing the demetallization agent. The demetallization auxiliary agent has strong chelating capacity in an aqueous phase, and can transfer the metal chelated by the demetallization agent to the demetallization auxiliary agent. In addition, the application of the demetallization agent and the demetallization auxiliary agent to non-acid crude oil demetallization is disclosed. The demetallization agent and the demetallization auxiliary agent are suitable for removing metals such as nickel and vanadium in crude oil, have high demetallization agent grafting rate, increase the contact time of the demetallization agent and the oil phase, and have the characteristics of low cost, easy production and environmental friendliness.

Description

Technical Field

[0001] This invention relates to the field of crude oil pretreatment and refining technology, specifically to a crude oil demetallizing agent and demetallizing auxiliary agent with high dispersion stability and a core-shell structure containing chelating functional groups, a method for preparing the demetallizing agent, and its application method for metal removal from non-acidic crude oil. Background Technology

[0002] Since the 20th century, with continuous social progress and the development of science and technology, the extraction and demand for crude oil have gradually increased. Crude oil is not only used as an energy source but also as an important raw material for producing high-performance chemical materials. However, due to the complex composition of crude oil, it has gradually become heavier and of lower quality, causing various adverse effects on subsequent processing and utilization. Among these effects, heavy metals in crude oil can harm refining systems and products, damage catalysts in refining processes, cause high-temperature corrosion of equipment, and pollute the environment. In particular, changes in nickel and vanadium content have a significant impact on these situations, and nickel and vanadium are more difficult to remove than calcium and iron in crude oil. Therefore, the petroleum refining industry is paying increasing attention to the removal of nickel and vanadium from crude oil.

[0003] Nickel and vanadium in crude oil mainly exist as oil-soluble porphyrin compounds in the gums and asphaltenes of crude oil. Metalloporphyrins are complexes formed by the covalent and coordinate bonds between metal ions and organic porphyrin structures. Simultaneously, metalloporphyrins associate with gums and asphaltenes in crude oil through axial coordination, hydrogen bonding, and π-π bonds, forming stable compounds. The main metalloporphyrins in crude oil are ETIO, DPEP (deoxy-red porphyrin), DI-DPEP (bicyclic deoxy-red porphyrin), RHODO-ETIO, RHODO-DPEP, and RHODO-DI-DPEP. Their structures are shown in the figure below.

[0004]

[0005] Existing methods for removing metals are mainly divided into three categories: physical removal, chemical removal, and biological removal. Physical removal methods include distillation, acid extraction, solvent deasphalting, adsorption, and filtration. Distillation utilizes the boiling point differences between different components of crude oil, separating fractions with different boiling ranges. As the temperature increases, the heavy metal components in the crude oil are gradually separated from the lighter components, achieving the purpose of demetallization. However, this method has a low removal rate for heavy metals and has therefore been gradually replaced. Acid extraction uses a strong acid to inhibit the interaction between metals and porphyrins in the crude oil. Hydrogen ions released from the acid replace the metal ions, causing them to detach from the porphyrin structure and enter the aqueous phase as free ions. Electro-desalting then removes the metals. However, acid extraction causes significant corrosion to equipment due to the use of strong acids. Solvent deasphalting utilizes the different solubilities of liquid hydrocarbons on different components of residual oil to obtain deasphalted oil and deoiled asphalt with low levels of heavy metals and non-metals such as sulfur and nitrogen, thus removing heavy metals from the deasphalted oil. However, solvent deasphalting requires a large amount of solvent, resulting in high costs. Adsorption methods utilize the porous structure or functional groups on the surface of adsorbents to adsorb metals, such as activated carbon, clay, metal powder, molecular sieves, molecularly imprinted polymers, lignin, and resins. However, the acidity of the crude oil increases after removal, which is detrimental to subsequent processing. Filtration uses membranes with specific structures and properties to filter crude oil, selectively allowing certain components to pass through, thereby reducing the metal content and viscosity of the crude oil. However, filtration is sensitive to crude oil viscosity and is not suitable for high-viscosity crude oils; moreover, the membranes tend to become clogged after a period of use and require cleaning and regeneration.

[0006] Chemical removal methods are divided into hydrodemetallization, supercritical fluid methods, and chelation separation methods. Hydrodemetallization involves hydrogenating metal compounds such as metal porphyrins and naphthenates in crude oil, causing them to decompose on the catalyst surface and deposit the metals. Catalytic hydrogenation can saturate some unsaturated hydrocarbons and effectively remove sulfur, nitrogen, and heavy metals from crude oil; however, it is complex, uses expensive catalysts, and is not suitable for industrial applications. Supercritical fluid methods utilize the acidic or alkaline properties of supercritical water, which, under certain conditions, can break the bonds between metals and porphyrin rings, allowing the metals to detach from the porphyrin ring and be removed as water-soluble ions. However, supercritical fluid methods have very strict requirements for reaction conditions and are not easily industrialized. Chelation demetallization involves adding a demetallizing agent to crude oil. This agent is a substance with a strong chelating ability for metals. At the oil-water interface, it chelates with metal ions in the metalloporphyrins of the oil phase, converting them into oil-insoluble substances. These metal ions are then carried into the aqueous phase and settle out with the water during the electro-desalting process. The principle is illustrated in the diagram below. Chelation demetallization offers advantages such as not altering the original process, low cost, and good demetallization effect, thus attracting widespread attention and becoming a research hotspot.

[0007]

[0008] Biological removal uses the degradation effect of microorganisms to remove metals from crude oil. However, biological removal takes a long time and has low removal efficiency.

[0009] Chinese patent CN108264925A discloses a non-acidic organic-inorganic hybrid material with a core-shell structure, consisting of a core made of silica, alumina, etc., and a shell made of polymers with functional groups such as pyrrolidone, pyridine, crown ether, imidazole, and carbazole. This demetallizing agent can effectively remove heavy metals from crude oil, is phosphorus-free, and is environmentally friendly; moreover, it is not acidic and will not corrode equipment. However, the low number of surface free radicals in its core leads to a low grafting rate and a limited number of effective functional groups. Its high core density results in uneven dispersion in the aqueous phase, excessively fast sedimentation, and reduced contact time with metals in the oil phase, leading to a lower removal rate. The demetallizing process is overly complex, involving the preparation of the core, intermediates, and finally the demetallizing agent, which is not conducive to industrial production. Its shell is mostly neutral, resulting in weak chelation effects on heavy metals and a low removal rate. Furthermore, its utilization rate is low, and regeneration is difficult.

[0010] It is evident that existing demetallizers have technical problems, requiring improvements to both the core and shell materials to enhance their overall performance and usability for industrial applications. Summary of the Invention

[0011] Existing demetallizing agents not only cause equipment corrosion but also increase the acidity of jet fuel and diesel, reducing the efficiency of electro-desalting. In addition, existing demetallizing agents are all hydrophilic. During electro-desalting, the demetallizing agent is in the aqueous phase while the metal is in the oil phase. The chelating groups in the demetallizing agent cannot come into good contact with the metal, resulting in poor metal removal.

[0012] The main objective of this invention is to provide a demetallizing agent with a core-shell structure. This agent can efficiently remove heavy metals such as nickel and vanadium from crude oil, exhibiting good hydrophilic and lipophilic properties, high grafting rate, low cost and easy availability, simple manufacturing process, and strong chelation ability for heavy metals. Advantageous embodiments of this invention are the subject of the dependent claims.

[0013] The second objective of this invention is to provide a method for preparing a demetallizing agent, wherein the preparation method uses nanoparticle-modified composite materials to improve their stability, dispersibility and biocompatibility while retaining the original material properties.

[0014] The third objective of this invention is to provide a use for a demetallization agent that transfers heavy metals chelated on the demetallization agent to the demetallization agent, thereby regenerating the demetallization agent and improving the removal rate.

[0015] The fourth objective of this invention is to provide a method for applying a demetallizing agent and a demetallizing auxiliary agent to remove metals from non-acidic crude oil, and to provide a demetallizing agent and a demetallizing auxiliary agent with a core-shell structure and chelating functional groups for removing metals from non-acidic crude oil.

[0016] According to the present invention, a demetallizing agent is provided, the demetallizing agent comprising a core-shell structure, the core-shell structure comprising an organic material with chelating functional groups, the core-shell structure comprising a core and a shell layer, the core comprising a polymer material with double bonds, the shell layer being composed of an amphiphilic (hydrophilic and lipophilic) polymer and having functional groups with strong metal chelating ability attached to its surface; wherein, the shell layer comprises a polymer chain, the polymer chain being brushed and attached to the surface of the shell layer, the polymer chain comprising one or more polymers with the following functional groups: formic acid, amide, dithiocarbamate, sulfonic acid, and phosphoric acid functional groups.

[0017] In a preferred embodiment of the present invention, the polymer having a double bond structure is selected from at least one of submicron-sized polybutadiene polymers, polystyrene polymers, polypropyne polymers, and polyisoprene polymers.

[0018] The present invention also relates to the use of a metal removal agent for use in conjunction with the aforementioned metal removal agent, the metal removal agent comprising a substance having metal chelating ability in aqueous solution.

[0019] Specifically, the demetallizing agent is a monomer or polymer with a functional group that has strong chelating ability in the aqueous phase, such as carboxylic acids, dithiocarbamates, sulfonic acids, phosphoric acids, and some organic acids.

[0020] This invention also relates to a method for preparing a demetallizing agent, the method comprising the following steps:

[0021] Step S01: Add a polymer with a double bond structure to deionized water to obtain a pretreatment solution;

[0022] Step S02: Add an initiator to the pretreatment solution to obtain a mixed solution;

[0023] Step S03: The mixed solution is stirred to completely dissolve the initiator in the mixed solution, and then the reaction temperature is raised to 60℃-100℃ to allow the initiator to fully react with the polymer having a double bond structure.

[0024] Step S04: Dissolve a functional group monomer in deionized water to obtain a transition solution; mix the transition solution with the mixed solution; continue the stirring process; maintain the reaction temperature at 60℃-100℃; and obtain an emulsion;

[0025] Step S05: Add the emulsion to a dialysis bag to remove small molecule impurities from the emulsion, and obtain a demetallizing agent.

[0026] Specifically, in step S01, small molecules in the polymer with a double bond structure are removed by dialysis before adding the polymer with the double bond structure to deionized water.

[0027] In a preferred embodiment of the present invention, the initiator is selected from potassium persulfate, potassium persulfate and sodium sulfite and azobisisobutyronitrile, and the amount of the initiator is 2.0% of the polymer particles by mass.

[0028] In a preferred embodiment of the present invention, the stirring process is carried out at a speed of 400-800 r / min, and nitrogen gas is introduced throughout the process.

[0029] In a preferred embodiment of the present invention, the weight percentage of the functional group monomer is equal to the weight percentage of the polymer having a double bond structure.

[0030] In a preferred embodiment of the present invention, the functional group monomer is selected from one of acrylic acid, dithiocarbamate acrylamide, vinyl p-toluenesulfonic acid, and methacrylic acid.

[0031] In a preferred embodiment of the present invention, the polymer having a double bond structure is selected from at least one of submicron-sized polybutadiene polymers, polystyrene polymers, polypropyne polymers, and polyisoprene polymers.

[0032] The present invention also relates to a method for applying the demetallizing agent and the demetallizing auxiliary agent as described above in the removal of metals from non-acid crude oil, comprising the following steps: preheating the non-acid crude oil, adding the demetallizing agent and the demetallizing auxiliary agent to the preheated non-acid crude oil, placing the preheated non-acid crude oil with the added demetallizing agent and the demetallizing auxiliary agent into an electrostatic desalting instrument for electrostatic desalting to remove the metals from the non-acid crude oil, thereby obtaining non-acid crude oil after metal removal.

[0033] This invention provides a metallizing agent that transforms the core of the metallizing agent from micron-sized inorganic particles as in existing technologies into submicron-sized organic polymers. This improves the dispersion stability of the polymer, extending its settling time and increasing the chelation time between the metallizing agent and heavy metals. Simultaneously, the synthesis method of the metallizing agent is optimized, increasing the grafting rate of the polymer chains in the shell to a certain extent, significantly improving the mass transfer efficiency of metal from the oil phase to the aqueous phase interface. With its high grafting rate, high dispersion stability, and controllable side chain length, the adsorption capacity of the emulsion-like metallizing agent is greatly enhanced, significantly saving resources. Furthermore, based on this metallizing agent, a metallizing auxiliary agent with stronger chelation ability for heavy metals in the aqueous phase is introduced. This auxiliary agent transfers the metal on the metallizing agent at the phase interface to the metallizing auxiliary agent in the aqueous phase, achieving partial regeneration of the metallizing agent. The regenerated metallizing agent then chelates the metal in the oil phase, greatly improving the removal rate of the metallizing agent. In short, the positive effects of this invention are:

[0034] (1) A demetallizer with a core-shell structure is provided; the demetallizer has a core-shell structure, a high grafting rate of polymer chains, and high dispersion stability, which increases the contact time between the demetallizer and the oil phase and greatly improves the electrostatic adsorption and chelation ability.

[0035] (2) A demetallization auxiliary agent is provided, which has a strong chelating ability in the aqueous phase, transfers the metal chelated by the demetallization agent to the demetallization auxiliary agent, realizes the regeneration of the demetallization agent, and improves the removal rate.

[0036] (3) A method for preparing the demetallizing agent and a process for demetallizing non-acidic crude oil using the demetallizing agent and demetallizing auxiliary agent are provided.

[0037] (4) The demetallizing agent and demetallizing auxiliary agent of the present invention are suitable for removing metals such as nickel and vanadium from crude oil. The demetallization rate is >55%, the devanadiumization rate is >70%, the dosage is small, and it has the characteristics of low cost, easy production and environmental friendliness.

[0038] Further details and advantages of the invention are described with reference to the embodiments shown in the accompanying drawings. Attached Figure Description

[0039] Some embodiments of the invention have been described herein by way of example only, with reference to the accompanying drawings. Reference will now be made in detail to the drawings, and it is emphasized that the details shown are by way of example and for the purpose of illustrative discussion of embodiments of the invention. In this regard, the description taken in conjunction with the drawings will make it clear to those skilled in the art how to practice embodiments of the invention.

[0040] In the attached diagram:

[0041] Figure 1 This is a schematic diagram of the chemical structure of the demetallizing agent of the present invention.

[0042] Figure 2 This is a schematic flowchart of the preparation method of the demetallizing agent of the present invention.

[0043] Figure 3 This is a schematic diagram illustrating the working principle of the preparation method of the demetallizing agent of the present invention.

[0044] Figure 4 This is a schematic flowchart illustrating the application method of the demetallizing agent of the present invention for metal removal from non-acidic crude oil.

[0045] Figure 5 This diagram shows a process flow diagram of the demetallizing agent of the present invention for removing metals from non-acidic crude oil. Detailed Implementation

[0046] The following describes, with reference to the accompanying drawings, the preparation of the core-shell structured demetallizing agent of the present invention and specific embodiments for metal removal from non-acidic crude oil using the aforementioned demetallizing agent and demetallizing auxiliary agent. It should be noted that the implementation of the present invention is not limited to the following embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. Furthermore, the accompanying drawings of the present invention are only simple schematic illustrations and are not depictions based on actual dimensions. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention.

[0047] Please see Figure 1 , Figure 1This is a schematic diagram of the chemical structure of the demetallizing agent of the present invention. The present invention discloses a demetallizing agent comprising a core-shell structure, wherein the core-shell structure is composed of an organic material with chelating functional groups, the core-shell structure comprising a core and a shell, wherein the core is composed of a polymer material with double bonds, and the shell is composed of an amphiphilic polymer.

[0048] More specifically, the core is composed of submicron-sized organic polymer particles, selected from at least one of submicron-sized polymers with double bond structures, such as polybutadiene, polystyrene, polypropyne, and polyisoprene. The shell is a hydrophilic-lipophilic (amphiphilic) polymer with functional groups grafted onto its surface, possessing strong electrostatic adsorption and metal chelating capabilities. The shell includes a polymer chain brush-grafted onto its surface, the polymer chain comprising polymers with one or more of the following functional groups: formic acid, amide, dithiocarbamate, sulfonic acid, and phosphoric acid functional groups.

[0049] Please see Figure 2 , Figure 2 This is a schematic flowchart of the preparation method of the demetallizing agent of the present invention. The present invention provides a method for preparing a demetallizing agent, the preparation method comprising the following steps:

[0050] Step S01: Add a polymer with a double bond structure to deionized water to obtain a pretreatment solution;

[0051] Step S02: Add an initiator to the pretreatment solution to obtain a mixed solution;

[0052] Step S03: The mixed solution is stirred to completely dissolve the initiator in the mixed solution, and then the reaction temperature is raised to 60℃-100℃ to allow the initiator to fully react with the polymer having a double bond structure.

[0053] Step S04: Dissolve a functional group monomer in deionized water to obtain a transition solution; mix the transition solution with the mixed solution; continue the stirring process; maintain the reaction temperature at 60℃-100℃; and obtain an emulsion;

[0054] Step S05: Add the emulsion to a dialysis bag to remove small molecule impurities from the emulsion, and obtain a demetallizing agent.

[0055] In step S01, small molecules in a polymer with a double bond structure are removed by dialysis before adding the polymer to deionized water.

[0056] Further, 3.5-7.0 g of the polymer with double bonds (after dialysis to remove small molecules) was added to 204.7 g of deionized water to obtain the pretreatment solution. Then, 0.04-0.08 g of the initiator was weighed and added to a 500 ml three-necked flask. The mixture was stirred vigorously at 400-800 rpm under nitrogen protection throughout. After the solution was fully mixed and the initiator completely dissolved, the reaction temperature was increased to 60℃-100℃, and vigorous stirring was continued for about half an hour to ensure complete reaction between the initiator and the polymer with double bonds. After stirring for about 30-60 minutes, 2.0-4.0 g of the functional group monomer was weighed and dissolved in 90-100 ml of deionized water to obtain the transition solution, which was then quickly added to the three-necked flask. The temperature was maintained at 60℃-100℃ and the stirring rate at 400-800 rpm, and the reaction was continued for 1-2 hours to obtain an emulsion. After synthesis, the resulting emulsion was added to a dialysis bag to remove small molecule impurities from the system, yielding a demetallizing agent.

[0057] Please see Figure 3 , Figure 3 This is a schematic diagram illustrating the working principle of the preparation method of the metal removal agent of the present invention. In this embodiment, the metal removal agent includes a vesicle 10, which includes a water vesicle 11, an oil vesicle 12, and a core-shell structure 20. The core-shell structure 20 includes a core 21 and a shell 22. The core 21 is formed in the core-shell structure 20, and polymer chains 23 are formed on the surface of the shell 22. The polymer chains 23 chelate metal 30. The hydrophilic and lipophilic properties of the metal removal agent refer to its ability to exist stably at the oil-water interface, being soluble in both water and oil. This allows the effective functional groups on the polymer chains to enter the oil phase and chelate with the metal, facilitating the transfer between oil and water and increasing the mass transfer rate of metal from the oil phase to the aqueous phase. The low core density of the metal removal agent results in better dispersibility and a longer contact time with the metal in the oil phase, increasing the chelation time between the metal removal agent and the metal and further improving the removal efficiency. Demetallizers with chelating functional groups have a stronger electrostatic interaction with metals and are more likely to chelate with them. Simultaneously, the shell of the demetallizer is a polymer, and the polymer chains (also called polymer brushes) on its surface have a large number of functional groups. This increases the grafting density of the demetallizer, leading to a higher density of functional groups and thus a stronger chelation effect on the metal, resulting in a higher metal removal rate.

[0058] and cooperate Figure 2As can be seen, the demetallizing agent enters the oil phase along with the aqueous phase in the emulsion, forming a water-in-oil emulsion through shear emulsification. At the oil-water interface, the side chains chelate and electrostatically adsorb metals such as nickel and vanadium in the crude oil, pulling the metals from the oil phase into the aqueous phase. Further electrostatic desalting and oil-water separation significantly improve the mass transfer efficiency of metals from the oil phase to the aqueous phase interface. With its high grafting rate, high dispersion stability, and controllable side chain length, the adsorption capacity of the emulsion-like polymer chains (also known as polymer brushes) is greatly enhanced, significantly saving resources.

[0059] In addition, the present invention provides a demetallization adjuvant for use in conjunction with the aforementioned demetallization agent, the demetallization adjuvant comprising a substance having metal chelating ability in aqueous solution.

[0060] In one embodiment, the demetallizing agent is a monomer or polymer with a functional group that has strong chelating ability in the aqueous phase, such as carboxylic acids, dithiocarbamates, sulfonic acids, phosphoric acids, and some organic acids.

[0061] In addition, please see Figure 4 , Figure 4 This is a flowchart illustrating the application method of the demetallizing agent of the present invention for metal removal from non-acidic crude oil. The present invention also provides a method for applying the demetallizing agent and the demetallizing auxiliary agent to remove metals from non-acidic crude oil, comprising the following steps: Step S11: Preheating the non-acidic crude oil; Step S12: Adding the demetallizing agent and the demetallizing auxiliary agent to the preheated non-acidic crude oil; Step S13: Placing the preheated non-acidic crude oil with the added demetallizing agent and the demetallizing auxiliary agent into an electrostatic desalting instrument for electrostatic desalting; Step S14: Removing the metals from the non-acidic crude oil to obtain non-acidic crude oil after metal removal.

[0062] Furthermore, the above application methods can be detailed as follows:

[0063] Step S11: Crude oil preheating and addition of demetallizing agent

[0064] Non-acidic crude oil is preheated to 90°C. A demetallizing agent and a demetallizing auxiliary agent with a core-shell structure and chelating functional groups are added to the preheated crude oil. The amount of the demetallizing agent and the demetallizing auxiliary agent added is 100-2000 ppm, the amount of water added is 0-0.2 times the mass of the crude oil, and the amount of demulsifier added is 10 ppm. Emulsification is carried out using a high-speed shear mill with a mixing intensity of 4-11 kr / min and a mixing time of 0-4 min to obtain preheated crude oil with the addition of the demetallizing agent and the demetallizing auxiliary agent.

[0065] Step S12: Electro-desalting to remove metals

[0066] The preheated crude oil obtained in step S11, with the addition of demetallizing agent and demetallizing auxiliary agent, is placed into an electrostatic desalting apparatus for electrostatic desalting to separate water from crude oil. The process conditions are as follows: temperature 90-150℃, constant temperature for 10 minutes; low pressure intensity 200-800V, low pressure time 20 minutes; high pressure intensity 800-1200V, high pressure time 10 minutes; settling time 60 minutes. The crude oil and electrostatic desalting wastewater are separated, and the metals in the non-acidic crude oil are removed to obtain non-acidic crude oil after electrostatic desalting.

[0067] Step S13: Collect analytes

[0068] Sub-step S131: Temperature rise process for collected samples

[0069] Analysis of non-acidic crude oil after electro-desalting in step S12: Weigh the electro-desalted crude oil and place it in a quartz crucible, then transfer it to a muffle furnace for programmed heating:

[0070] The temperature was raised from room temperature to 100°C over 30 minutes and held for 1 hour; then raised to 600°C over 240 minutes and held for 6 hours.

[0071] End the heating program and allow the temperature to drop to room temperature;

[0072] Sub-step S132: Concentration and hydrolysis

[0073] Dissolve the calcined components in 10 ml of 2% hydrochloric acid solution and 10 ml of 2% nitric acid solution, then heat and evaporate on an electric furnace until concentrated to about 3 ml and then stop heating; dilute to 100 ml in a volumetric flask with deionized water.

[0074] Sub-step S133 Blank test

[0075] While sub-step S131 is being performed, a clean quartz crucible is simultaneously subjected to the complete analysis process to compare and determine the metal content that may be introduced during the experiment in order to ensure the accuracy of the data.

[0076] Step S14 Metal Content Determination

[0077] The metal content of the oil sample collected in step S13 was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Multiple exemplary embodiments:

[0078] Example 1

[0079] The preparation method of a highly dispersible core-shell structured demetallizing agent with chelating functional groups is as follows:

[0080] Weigh 3.0 g of the polymer with double bonds (after dialysis to remove small molecules) and add it to 204.7 g of deionized water to obtain a pretreatment solution. Then weigh 0.06 g of initiator KPS and 2.0% of the mass of the spherical polymer core particles. Add the mixture to a 500 ml three-necked flask and stir vigorously at 500 rpm under nitrogen protection throughout. After the solution is fully mixed and the initiator is completely dissolved, raise the reaction temperature to 80 °C and continue stirring vigorously for about half an hour to ensure the initiator reacts fully with the polymer with double bonds. After stirring for about 30 minutes, weigh 3.0 g of the functional group monomer, dissolve it in 90 ml of deionized water to obtain a transition solution, and quickly add the transition solution to the three-necked flask. Maintain the reaction temperature at 80 °C and the stirring rate at 500 rpm and continue the reaction for 1 hour. After synthesis, the emulsion containing polymer chains (polymer brushes) was added to a dialysis bag to remove small molecule impurities from the system. After the conductivity of the dialysis solution stabilized, it was taken out to obtain a demetallizing agent.

[0081] Example 2

[0082] The preparation method of a highly dispersible core-shell structured demetallizing agent with chelating functional groups is as follows:

[0083] Weigh 5.30 g of the polymer with double bonds (after dialysis to remove small molecules) and add it to 204.7 g of deionized water to obtain a pretreatment solution. Then weigh 0.06 g each of the initiator potassium persulfate and sodium sulfite, and add the mixture to a 500 ml three-necked flask. Stir vigorously at 500 rpm under nitrogen purging throughout the process. After the solution is fully mixed and the initiator is completely dissolved, raise the reaction temperature to 80°C and continue stirring vigorously for about half an hour to ensure complete reaction between the initiator and the polymer with double bonds. After stirring for about 30 minutes, weigh 3.0 g of acrylic acid and dissolve it in 90 ml of deionized water to obtain a transition solution. Quickly add the transition solution to the three-necked flask. Maintain the reaction temperature at 80°C and the stirring rate at 500 rpm, and continue the reaction for 1 hour. After synthesis, the emulsion containing polymer chains (polymer brushes) was added to a dialysis bag to remove small molecule impurities from the system. After the conductivity of the dialysis solution stabilized, it was taken out to obtain a demetallizing agent.

[0084] Example 3

[0085] The preparation method of a highly dispersible core-shell structured demetallizing agent with chelating functional groups is as follows:

[0086] 5.30 g of a polymer with a double bond structure (dialyzed to remove small molecules) was added to 204.7 g of deionized water to obtain a pretreatment solution. Then, 0.06 g of potassium persulfate initiator was weighed and added to a 500 ml three-necked flask. The mixture was stirred vigorously at 500 rpm under nitrogen purging. After the solution was fully mixed and the initiator completely dissolved, the reaction temperature was raised to 80°C, and vigorous stirring was continued for about half an hour to ensure complete reaction between the initiator and the polymer with the double bond structure. After stirring for about 30 minutes, 3.0 g of a functional group monomer was weighed and dissolved in 90 ml of deionized water to obtain a transition solution, which was quickly added to the three-necked flask. The reaction temperature was maintained at 80°C and the stirring rate at 500 rpm, and the reaction was continued for 2 hours. After synthesis, the emulsion containing polymer chains (polymer brushes) was added to a dialysis bag to remove small molecule impurities from the system. After the conductivity of the dialysis solution stabilized, it was taken out to obtain a demetallizing agent.

[0087] Example 4

[0088] The preparation method of a highly dispersible core-shell structured demetallizing agent with chelating functional groups is as follows:

[0089] 5.30 g of a polymer with a double bond structure (dialyzed to remove small molecules) was added to 204.7 g of deionized water to obtain a pretreatment solution. Then, 0.16 g of potassium persulfate and 0.04 g of sodium sulfite (initiator) were weighed, representing 5.4% and 1.2% of the core mass, respectively. The mixture was added to a 500 ml three-necked flask and stirred vigorously at 500 rpm under nitrogen purging. After the solution was fully mixed and the initiator completely dissolved, the reaction temperature was raised to 80 °C, and vigorous stirring continued for about half an hour to ensure complete reaction between the initiator and the polymer with the double bond structure. After stirring for about 30 minutes, 3.0 g of the functional group monomer was weighed and dissolved in 90 ml of deionized water to obtain a transition solution, which was quickly added to the three-necked flask. The reaction temperature was maintained at 80 °C and the stirring rate at 500 rpm, and the reaction continued for 1 hour. After synthesis, the emulsion containing polymer chains (polymer brushes) was added to a dialysis bag to remove small molecule impurities from the system. After the conductivity of the dialysis solution stabilized, it was taken out to obtain a demetallizing agent.

[0090] Example 5

[0091] The preparation method of a highly dispersible core-shell structured demetallizing agent with chelating functional groups is as follows:

[0092] Weigh 5.30 g of the polymer with double bonds (after dialysis to remove small molecules) and add it to 204.7 g of deionized water to obtain a pretreatment solution. Then weigh 0.16 g of potassium persulfate and 0.04 g of sodium sulfite as initiators, and add the mixture to a 500 ml three-necked flask. Stir vigorously at 500 rpm under nitrogen purging throughout the process. After the solution is fully mixed and the initiator is completely dissolved, raise the reaction temperature to 80°C and continue stirring vigorously for about half an hour to ensure complete reaction between the initiator and the polymer with double bonds. After stirring for about 30 minutes, weigh 3.0 g of the functional group monomer, dissolve it in 90 ml of deionized water to obtain a transition solution, and quickly add the transition solution to the three-necked flask. Maintain the reaction temperature at 80°C and the stirring rate at 500 rpm, and continue the reaction for 3 hours. After synthesis, the emulsion containing polymer chains (polymer brushes) was added to a dialysis bag to remove small molecule impurities from the system. After the conductivity of the dialysis solution stabilized, it was taken out to obtain a demetallizing agent.

[0093] Example 6

[0094] The functional group monomers in Examples 1-5 were replaced with acrylamide, dithiocarbamate acrylamide, and vinyl p-toluenesulfonic acid.

[0095] Application Example 1

[0096] Please see Figure 5 and cooperate Figure 4 , Figure 5 This diagram illustrates the process flow for metal removal from non-acidic crude oil using the demetallizing agent of the present invention. The application of the highly dispersible core-shell structured demetallizing agent and demetallizing adjuvant of the present invention for metal removal from non-acidic crude oil includes the following steps:

[0097] Step S11: Crude oil preheating and addition of demetallizing agent

[0098] The crude oil used is from Liaohe River, which has a nickel content of 80 ppm and a vanadium content of 2 ppm.

[0099] Non-acidic crude oil is preheated to 90°C. A demetallizing agent and a demetallizing auxiliary agent are added to the preheated crude oil at a concentration of 400 ppm. Water is added at a concentration of 0.1 times the mass of the crude oil, and demulsifier FC-9303 is added at a concentration of 10 ppm. Emulsification is performed using a high-speed shear mill at a mixing intensity of 8 kr / min and a mixing time of 2 min to obtain preheated crude oil with the addition of the demetallizing agent and demetallizing auxiliary agent.

[0100] Step S12: Electro-desalting to remove metals

[0101] The preheated crude oil obtained in step S11, with the addition of demetallizing agent and demetallizing auxiliary agent, is placed into an electrostatic desalting apparatus for electrostatic desalting to separate water from crude oil. The process conditions are as follows: temperature 120℃, constant temperature for 10 minutes; low pressure intensity 500V, low pressure time 20 minutes; high pressure intensity 1000V, high pressure time 10 minutes; settling time 60 minutes. The crude oil and electrostatic desalting wastewater are separated, and the metals in the non-acidic crude oil are removed to obtain non-acidic crude oil after electrostatic desalting.

[0102] Step S13: Collect analytes

[0103] Sub-step S131: Temperature rise process for collected samples

[0104] Analysis of non-acidic crude oil after electro-desalting in step S12: Weigh the electro-desalted crude oil and place it in a quartz crucible, then transfer it to a muffle furnace for programmed heating:

[0105] The temperature was raised from room temperature to 100°C over 30 minutes and held for 1 hour; then raised to 600°C over 240 minutes and held for 6 hours.

[0106] End the heating program and allow the temperature to drop to room temperature;

[0107] Sub-step S132: Concentration and hydrolysis

[0108] Dissolve the calcined components in 10 ml of 2% hydrochloric acid solution and 10 ml of 2% nitric acid solution, then heat and evaporate on an electric furnace until concentrated to about 3 ml and then stop heating; dilute to 100 ml in a volumetric flask with deionized water.

[0109] Sub-step S133 Blank test

[0110] While sub-step S131 is being performed, a clean quartz crucible is simultaneously subjected to the complete analysis process to compare and determine the metal content that may be introduced during the experiment in order to ensure the accuracy of the data.

[0111] Step S14 Analysis and Determination

[0112] The metal content of the oil sample collected in step S13 was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Application Examples 2-6

[0113] Application Examples 2-6 are largely the same as Application Example 1. The difference lies in the amounts of the metal removal agent and metal removal auxiliary agent added in Application Examples 2-6, which are 600, 800, 1000, 1200, and 1400 ppm, respectively. The metal removal effects of Application Examples 1-6 are shown in Table 1 below.

[0114] Table 1. Metal removal effect of application examples 1-6.

[0115]

[0116] Application Examples 7-12

[0117] Application Examples 7-12 are largely the same as Application Examples 1-6. The difference is that in Application Examples 7-12, only a metal removal agent is added, without any metal removal auxiliaries. The metal removal effect of Application Examples 7-12 is shown in Table 2 below.

[0118] Table 2. Metal removal effect of application examples 7-12.

[0119] Dosage of metal removal agent Nickel removal rate Vanadium removal rate Application Example 7 400 19.7 13.33 Application Example 8 600 18.33 26.67 Application Example 9 800 23.3 33.33 Application Example 10 1000 28.95 26.67 Application Example 11 1200 43.94 9.88 Application Example 12 1400 19.7 13.33

[0120] Application Examples 13-17

[0121] Application Examples 13-17 are largely the same as Application Examples 2-6. The difference is that the crude oil used in Application Examples 13-17 is Middle Eastern crude oil, with a nickel content of 21.78 ppm and a vanadium content of 51.15 ppm. The metal removal effect of Application Examples 13-17 is shown in Table 3 below.

[0122] Table 3. Metal removal effect of application examples 13-17.

[0123]

[0124] Application Examples 18-22

[0125] The methods used in Application Examples 18-22 are largely the same as those in Application Examples 13-17. The difference is that in Application Examples 18-22, only a metal removal agent is added, without any metal removal auxiliaries. The metal removal effects of Application Examples 18-22 are shown in Table 4 below.

[0126] Table 4. Metal removal effect of application examples 18-22.

[0127] Dosage of metal removal agent Nickel removal rate Vanadium removal rate Application Example 18 600 4.70 2.41 Application Example 19 800 6.30 3.01 Application Example 20 1000 7.58 6.30 Application Example 21 1200 10.01 6.96 Application Example 22 1400 18.81 12.90

[0128] Application Examples 23-27

[0129] Application Examples 23-27 are largely the same as Application Examples 13-17. The difference is that the crude oil used in Examples 13-17 is Zhenhai crude oil, which has a nickel content of 22.77 ppm and a vanadium content of 51.48 ppm. The metal removal effect of Application Examples 23-27 is shown in the table below.

[0130] Table 5. Metal removal effect of application examples 23-27 5.

[0131]

[0132] Application Examples 28-32

[0133] The methods used in Application Examples 28-32 are largely the same as those in Application Examples 23-27. The difference is that in Application Examples 28-32, only a metal removal agent is added, without any metal removal auxiliaries. The metal removal effects of Application Examples 28-32 are shown in Table 6 below.

[0134] Table 6. Metal removal effect of application examples 28-32.

[0135] Dosage of metal removal agent Nickel removal rate Vanadium removal rate Application Example 28 600 6.25 4.52 Application Example 29 800 7.50 6.21 Application Example 30 1000 8.75 8.47 Application Example 31 1200 10.00 11.86 Application Example 32 1400 16.25 14.12

[0136] Application Examples 33-37

[0137] Application Examples 33-37 are largely the same as Application Examples 23-27. The difference is that the crude oil used in Application Examples 23-27 is unconverted residual oil with a nickel content of 36.19 ppm and a vanadium content of 59.61 ppm. The metal removal effect of Application Examples 33-37 is shown in Table 7 below.

[0138] Table 7. Metal removal effect of application examples 33-37

[0139]

[0140] Application Examples 38-42

[0141] The methods used in Application Examples 38-42 are largely the same as those in Application Examples 33-37. The difference is that in Application Examples 38-42, only a metal removal agent is added, without any metal removal auxiliaries. The metal removal effects of Application Examples 38-42 are shown in Table 8 below.

[0142] Table 8. Metal removal effect of application examples 38-42.

[0143] Dosage of metal removal agent Nickel removal rate Vanadium removal rate Application Example 38 600 15.15 16.11 Application Example 39 800 15.94 21.42 Application Example 40 1000 21.74 39.11 Application Example 41 1200 26.08 44.24 Application Example 42 1400 29.86 49.73

[0144] Application Examples 43-47

[0145] Application Examples 43-47 are largely the same as Application Examples 33-37. The difference is that the crude oil used in Application Examples 33-37 is heavy wax oil with a nickel content of 1.40 ppm and a vanadium content of 1.40 ppm. The metal removal effect of Application Examples 43-47 is shown in the table below.

[0146] Table 9. Metal removal effect of application examples 43-47.

[0147]

[0148] Application Examples 48-52

[0149] The methods used in Application Examples 48-52 are largely the same as those in Application Examples 43-47. The difference is that in Application Examples 48-52, only a metal removal agent is added, without any metal removal auxiliaries. The metal removal effects of Application Examples 48-52 are shown in Table 10 below.

[0150] Table 10. Metal removal effect of application examples 48-52.

[0151]

[0152]

[0153] While the present invention has been disclosed above with reference to the preferred embodiments described herein, it is not intended to limit the invention. Those skilled in the art can make modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of patent protection for this invention is determined by the claims appended to this specification. The present invention is not limited to any of the above-described embodiments or features. The present invention may include various additions or modifications to the described embodiments.

Claims

1. A metal removal agent, characterized in that: The demetallizing agent includes a core-shell structure, which is composed of an organic material with chelating functional groups. The core-shell structure includes a core and a shell, wherein the core includes a polymer with a double bond structure and the shell includes an amphiphilic polymer. The shell layer includes a polymer chain attached to the surface of the shell layer. The polymer chain includes one or more of the following functional groups: formic acid, amide, dithiocarbamate, sulfonic acid, and phosphoric acid. The polymer having a double bond structure is selected from at least one of submicron-sized polybutadiene polymers, polystyrene polymers, polypropyne polymers, and polyisoprene polymers.

2. A method for preparing a metallizing agent, characterized in that: The preparation method includes the following steps: Step S01: Add a polymer with a double bond structure to deionized water to obtain a pretreatment solution; Step S02: Add an initiator to the pretreatment solution to obtain a mixed solution; Step S03: The mixed solution is stirred to completely dissolve the initiator in the mixed solution, and then the reaction temperature is raised to 60℃-100℃ to allow the initiator to fully react with the polymer having a double bond structure. Step S04: Dissolve a functional group monomer in deionized water to obtain a transition solution, mix the transition solution with the mixed solution, continue the stirring process, maintain the reaction temperature at 60℃-100℃, and obtain an emulsion. as well as Step S05: Add the emulsion to a dialysis bag to remove small molecule impurities from the emulsion, and obtain a demetallizing agent; The initiator is selected from at least one of potassium persulfate, potassium persulfate, sodium sulfite, and azobisisobutyronitrile, and the amount of the initiator is 2.0% by mass of the polymer particles; The functional group monomer is selected from at least one of acrylic acid, dithiocarbamate acrylamide, vinyl p-toluenesulfonic acid and methacrylic acid; The polymer having a double bond structure is selected from at least one of submicron-sized polybutadiene polymers, polystyrene polymers, polypropyne polymers, and polyisoprene polymers.

3. The preparation method according to claim 2, characterized in that: The stirring process is carried out at a speed of 400-800 r / min, with nitrogen gas introduced throughout.

4. The preparation method according to claim 2, characterized in that: The weight percentage of the functional group monomer is equal to the weight percentage of the polymer having a double bond structure.

5. A method for metal removal from non-acidic crude oil, characterized in that: The method includes the following steps: Step 11: Preheat the non-acidic crude oil; Step 12: Add the demetallizing agent and a demetallizing auxiliary agent as described in claim 1 to the preheated non-acidic crude oil; Step 13: The preheated non-acidic crude oil, with the addition of the demetallizing agent and the demetallizing auxiliary agent, is placed into an electro-desalting instrument for electro-desalting; as well as Step 14: Remove the metal from the non-acidic crude oil to obtain non-acidic crude oil after metal removal.

6. Use of a metallizing agent for use in conjunction with a metallizing agent according to claim 1, wherein the metallizing agent comprises a substance having metal chelating ability in water.

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