Crude oil demetalization agent, preparation method and crude oil demetalization method

Abstract

The invention relates to the technical field of crude oil metal removal, in particular to a crude oil demetalization agent, a preparation method and a crude oil demetalization method. The crude oil demetalization agent comprises the following components in parts by weight: 5-60 parts by weight of phosphorous acid compounds, 1-5 parts by weight of a metal-removing agent, 1-5 parts by weight of a metal-removing agent, and 1-5 parts by weight of a metal-removing agent. 0.05 to 30 parts by weight of a reducing agent; 1-50 parts by weight of a chelating agent; 1-30 parts by weight of a phase transfer agent; and 5-50 parts by weight of a solvent. The crude oil demetallization agent is used for removing metal ions Mn < + > in crude oil, the metal ions Mn < + > are metal ions corresponding to one or more metal elements in VIII-family and IIA-family metals, the removal rate of the crude oil demetallization agent on the VIII-family metal elements in the crude oil is larger than or equal to 64%, and the removal rate of the crude oil demetallization agent on the IIA-family metal elements in the crude oil is larger than or equal to 70%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of crude oil metal removal, and particularly relates to a crude oil demetalizing agent, a preparation method thereof and a crude oil demetalizing method. BACKGROUND

[0002] With the continuous exploitation and utilization of global oil resources, oil fields enter the later stage of exploitation, and a large amount of heavy oil or remaining oil from primary and secondary oil recovery is exploited by means of tertiary oil recovery technology such as chemical assisted recovery agent. The properties of oil gradually change, resulting in the continuous increase of the proportion of heavy oil and the content of metal in oil, and most of the metal exists in heavy oil. The metal in heavy oil is closely combined with many organic matters. With the continuous consumption of fossil energy and the continuous exploitation, this trend is still increasing.

[0003] The presence of calcium and iron in crude oil can cause many problems in the oil processing process. They can not only directly or indirectly cause fouling and corrosion of equipment and pipelines during oil transportation, but also significantly reduce the activity of catalysts in the subsequent refining process, ultimately leading to catalyst deactivation. Calcium exists in the form of organic acid salts such as calcium alkanoate and calcium fatty acid in crude oil, and will decompose into inorganic compounds such as CaO or CaS under high temperature conditions in the refining process. The activity of the molecular sieve catalyst commonly used in catalytic cracking depends on the acidic sites on its surface, which are the core of breaking the C-C bond of hydrocarbon molecules. Calcium oxides have strong basicity and can neutralize the acidic sites of the catalyst, directly consuming the acidic centers, resulting in a significant decrease in the cracking ability of the catalyst for hydrocarbons and a decrease in oil yield. Calcium compounds have a high melting point and are difficult to decompose or migrate after depositing on the surface or in the pores of the catalyst, gradually blocking the microporous and mesoporous structures of the molecular sieve, preventing heavy hydrocarbon molecules in the crude oil from diffusing to the active sites inside the catalyst, and reducing the effective reaction area, further reducing the catalytic efficiency.

[0004] Iron in crude oil mainly exists in the form of naphthenic acid iron and porphyrin iron, and will be converted into inorganic compounds such as Fe3O4 and FeS in the high-temperature refining process. These iron oxides and sulfides have high melting points and low diffusivity, and will gradually accumulate on the surface of the catalyst particles, forming a dense layer of inorganic iron metal compounds covering the active sites of the catalyst, preventing the contact of reactants with active centers, and hindering the desorption of products, resulting in a sharp decrease in the reaction rate. In addition, the radius of iron ions is close to that of aluminum ions in the molecular sieve framework, and under high temperature conditions, iron ions may enter the molecular sieve framework by ion exchange and replace Al 3+The substitution disrupts the crystal structure of the molecular sieve, causing framework collapse and pore volume reduction, resulting in the catalyst losing its original shape selectivity and thermal stability, ultimately leading to rapid deactivation during recycling. Furthermore, the high stability and oil solubility of porphyrin compounds make it difficult to remove iron from crude oil; therefore, developing efficient removal technologies targeting their chemical structure is an important direction in crude oil processing.

[0005] Existing crude oil demetallization technologies can be divided into physical demetallization and chemical demetallization. Among them, chemical demetallization technology is more widely used due to its lower cost. Chemical demetallization technologies include chemical precipitation, chelation extraction, and hydrodemetallization. Among these, novel chelating agent demetallization technologies have gradually become a research hotspot in recent years due to their advantages such as minimal modification to existing refining equipment and low cost.

[0006] CN101085932A discloses a composite demetallizing agent for hydrocarbon oils, comprising the following components: (a) a demetallizing agent at 0.2-10 times the weight of calcium in the hydrocarbon oil, wherein the demetallizing agent is alkylbenzene sulfonic acid; (b) an adjuvant at 0.2-10 times the weight of calcium in the hydrocarbon oil, wherein the adjuvant is one or a combination of several of fructose acid, glycolic acid, lactic acid, disodium ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid, gluconic acid, tartaric acid, or citric acid; and (c) a demulsifier at 2-100 ppm of the weight of the hydrocarbon oil. However, the composite demetallizing agent in this technical solution can only remove metallic calcium and cannot simultaneously remove metallic iron.

[0007] CN112322339A discloses a crude oil metal chelating agent and its preparation method. The chelating agent is composed of 40wt%-60wt% iron ion imprinted polymer, 15wt%-25wt% organic polyacid, 5wt%-10wt% solubilizer, 5wt%-10wt% pH buffer, and 15wt%-30wt% deionized water. The mixture is placed in a reaction vessel at room temperature, and the reaction vessel is placed in an oven for high-temperature reaction. The iron ion imprinted polymer is composed of 40wt%-60wt% iron ion imprinted polymer, 15wt%-25wt% organic polyacid, 5wt%-10wt% solubilizer, 5wt%-10wt% pH buffer, and 15wt%-30wt% deionized water. The present invention provides a crude oil metal chelating agent by synthesizing functional monomers from pyridine carboxylic acid and propylthiourea, followed by polymerization with template ions and removal of the template ions. This agent exhibits an iron removal rate of over 85% and excellent demetallization performance. However, the composite demetallizing agent in this technical solution can only remove metallic iron and cannot simultaneously remove metallic calcium.

[0008] CN103374385A discloses a composition for removing heavy metals from hydrocarbon oils, its preparation method, and its application. The composition contains a demetallizing agent, a hydrogen donor, a chelating agent, a phase transfer agent, and a solvent. Based on the total weight of the composition, it contains: 15-45 wt% of the demetallizing agent, 1-69 wt% of the hydrogen donor, 8-35 wt% of the chelating agent, 4-15 wt% of the phase transfer agent, and 4-40 wt% of the solvent. The demetallizing agent is a substance capable of reacting with nickel and vanadium in hydrocarbon oils. However, when using this composition to remove calcium and iron, the dosage needs to be significantly increased, thus increasing costs and making it unsuitable for widespread application.

[0009] Based on the above, existing technologies have several technical problems that urgently need to be solved, such as the inability of crude oil demetallizers to efficiently remove both calcium and iron simultaneously, and the need to simultaneously achieve low dosage, mild removal conditions, and high metal removal rates in crude oil demetallizers. Summary of the Invention

[0010] To solve the above-mentioned technical problems, the present invention provides a crude oil demetallizing agent, which comprises the following components by weight, and the corresponding content of each component is as follows: Phosphorous compounds: 5-60 parts by weight; Reducing agent: 0.05-30 parts by weight; Chelating agent: 1-50 parts by weight; Phase transfer agent: 1-30 parts by weight; Solvent: 5-50 parts by weight; The structural formulas of the phosphorous compounds mentioned above are shown in Formula 1 and / or Formula 2: , , R1, R2, and R3 are independently H, or C1-C6 straight-chain or branched alkyl groups, or C6-C6... 12 One or more of the aryl groups; The crude oil demetallizing agent is used to remove metal ions M from crude oil. n+ The metal ion M n+ n represents the metal ion corresponding to one or more metallic elements in Group VIII and Group IIA, where n is an integer greater than or equal to 1.

[0011] Furthermore, the phosphorous compound is one or more of phosphorous acid, phosphite, and phosphite ester.

[0012] Further, the phosphites include, but are not limited to, one or more of the following: monoethyl phosphite, dimethyl phosphite, trimethyl phosphite, diethyl phosphite, triethyl phosphite, di-n-propyl phosphite, diisopropyl phosphite, tri-n-propyl phosphite, triisopropyl phosphite, mono-n-butyl phosphite, di-n-butyl phosphite, tri-n-butyl phosphite, di-sec-butyl phosphite, di-tert-butyl phosphite, tri-sec-butyl phosphite, tri-tert-butyl phosphite, di-n-pentyl phosphite, di-n-hexyl phosphite, tri-n-hexyl phosphite, diphenyl phosphite, triphenyl phosphite, and tricresyl phosphite.

[0013] Furthermore, the reducing agent is one or more of the following: reducing elemental metal, reducing gas, organic acid and its salt, inorganic salt and its complex salt.

[0014] Furthermore, the reducing metallic element includes, but is not limited to, one or more of iron powder, zinc powder, and aluminum powder.

[0015] Furthermore, reducing gases include, but are not limited to, hydrogen and sulfur dioxide.

[0016] Furthermore, the organic acids and their salts include, but are not limited to, L-ascorbic acid and its salts, D-isoascorbic acid and its salts, and oxalic acid and its salts.

[0017] Furthermore, the cations of the inorganic salt and its complex salts include, but are not limited to, one or more of sodium ions and ferrous ions.

[0018] Furthermore, the anions of the inorganic salts and their complex salts include, but are not limited to, one or more of sulfite, bisulfite, sulfate, and chloride ions.

[0019] Furthermore, the inorganic salts and their complex salts include, but are not limited to, one or more of sodium sulfite, sodium bisulfite, ferrous sulfate, ferrous ammonium sulfate, and ferrous chloride.

[0020] Furthermore, the chelating agent may include, but is not limited to, one or more of the following structural groups: carboxyl, phosphate, amino, imino, and hyponitro group.

[0021] Furthermore, the chelating agent includes, but is not limited to, one or more of the following: phosphoric acid, aminotrimethylenephosphonic acid (ATMP), hydroxyethylidene diphosphonic acid (HEDP), hydrolyzed polymaleic anhydride (HPMA), polyacrylic acid (PAA), ethylenediaminetetraacetic acid (EDTA) and its salts, ethacrylic acid and its salts, iminodisuccinic acid and its salts, triethylenetetramine, tetraethylenepentamine, and ethylenediamine.

[0022] Furthermore, when the chelating agent is hydrolyzed polymaleic anhydride (HPMA), its structural groups exhibit the chelation effect shown in Formula 3 with the metal ions: Formula 3

[0023] Among them, M n+ n represents the metal ion corresponding to one or more metallic elements in Group VIII and Group IIA, where n is an integer greater than or equal to 1.

[0024] Furthermore, when the chelating agent is phosphoric acid, aminotrimethylene phosphonic acid (ATMP), or hydroxyethylidene diphosphonic acid (HEDP), its structural groups exhibit the chelating effect shown in Formula 4 with the metal ions: Formula 4

[0025] In Formula 4, R4 is a C1-C5 carbon chain containing an imino, hyponitro, hydroxyl, or phosphate group, and M... n+ n represents the metal ion corresponding to one or more metallic elements in Group VIII and Group IIA, where n is an integer greater than or equal to 1.

[0026] Furthermore, the phase transfer agent is one or more of polyethylene glycol, etherified products of polyethylene glycol, and esterified products of polyethylene glycol.

[0027] Furthermore, the polyethylene glycol is of type PEG-400 or PEG-600.

[0028] Furthermore, the etherification products of the polyethylene glycol are polyethylene glycol monomethyl ether and polyethylene glycol ethylene ether.

[0029] Furthermore, the esterification product of the polyethylene glycol is polyethylene glycol monomethyl ether propylene ester.

[0030] Furthermore, the solvent is water or a non-aqueous solvent.

[0031] Furthermore, the non-aqueous solvent is one or more of organic alcohol solvents, organic ketone solvents, and organic ester solvents.

[0032] Furthermore, the organic alcohol solvent is one or more of methanol, ethanol, isopropanol, and benzyl alcohol.

[0033] Furthermore, the organic ketone solvent is acetone.

[0034] Furthermore, the organic ester solvent is an ester solvent containing carbonate ions.

[0035] Furthermore, the organic ester solvent includes, but is not limited to, ethylene carbonate and propylene carbonate.

[0036] Furthermore, the content of the phosphorous compound is preferably 10-50 parts by weight.

[0037] Furthermore, the content of the reducing agent is preferably 1-15 parts by weight.

[0038] Furthermore, the content of the chelating agent is preferably 10-30 parts by weight.

[0039] Furthermore, the content of the phase transfer agent is preferably 5-15 parts by weight.

[0040] Furthermore, the solvent content is preferably 10-30 parts by weight.

[0041] The present invention also provides a method for preparing the above-mentioned crude oil demetallizing agent, wherein a phosphorous compound, a reducing agent, a chelating agent, a phase transfer agent and a solvent are mixed evenly.

[0042] Furthermore, the mixing temperature is 20-50℃, and the time is 1-30 minutes.

[0043] Furthermore, the mixing rate is 200-500 rpm.

[0044] The present invention also provides a method for demetallizing crude oil, wherein the method involves using the above-mentioned crude oil demetallizing agent to remove metals from the crude oil.

[0045] Furthermore, the metal includes, but is not limited to, one or more of Group VIII and Group IIA metals.

[0046] Furthermore, based on the total weight of the crude oil, the content of the metal in the crude oil accounts for more than 10 mg / kg of the total mass of the crude oil.

[0047] Furthermore, the group VIII metals constitute 1-50 mg / kg of the total crude oil content.

[0048] Furthermore, the group IIA metals constitute 1-50 mg / kg of the total crude oil content.

[0049] Furthermore, the iron content in the group VIII crude oil is 5-25 mg / kg.

[0050] Furthermore, the calcium content in the group IIA crude oil is 10-20 mg / kg.

[0051] Furthermore, the crude oil demetallization method specifically involves adding the crude oil demetallizing agent to the crude oil at a rate of 10-2000 mg / kg of the total weight of the crude oil, and adding washing water and demulsifier to the system to remove metals from the crude oil.

[0052] Furthermore, the washing water accounts for 1-20 wt% of the total weight of the crude oil, and the demulsifier accounts for 1-80 ppm of the total weight of the crude oil.

[0053] Furthermore, the removal temperature is 50-180℃, the pressure is ≤1MPa, and the time is 10-300min.

[0054] Furthermore, the removal temperature is preferably 80-140℃.

[0055] Furthermore, the removal time is preferably 30-240 minutes.

[0056] Furthermore, the washing water accounts for 5-10 wt% of the total weight of the crude oil.

[0057] Furthermore, the pH value of the washing water is 6-9.

[0058] Furthermore, the washing water includes, but is not limited to, soft water, distilled water, and purified water. Any water-soluble solvent that does not affect the effect of the crude oil demetallizing agent can be used as washing water.

[0059] Furthermore, the demulsifier accounts for 10-50 ppm of the total weight of the crude oil.

[0060] Furthermore, the demulsifier is a non-ionic demulsifier, designed to ensure complete separation of the oil phase and the aqueous phase.

[0061] Furthermore, the demulsifier is preferably a polyether-based demulsifier.

[0062] Furthermore, the demulsifier is preferably a polyoxyethylene-polyoxypropylene copolymer.

[0063] Furthermore, the polyoxyethylene-polyoxypropylene copolymer includes, but is not limited to: polyoxypropylene-polyoxyethylene block copolymers initiated with alcohols, polyoxypropylene-polyoxyethylene block copolymers initiated with amines, polyoxypropylene-polyoxyethylene block copolymers initiated with phenolic resins and / or phenolic amine resins, and polyoxyethylene-polyoxypropylene block copolymers initiated with toluene diisocyanate as a chain extender.

[0064] Furthermore, the crude oil demetallizing agent has a removal rate of ≥64% for Group VIII metal elements in the crude oil and a removal rate of ≥70% for Group IIA metal elements in the crude oil.

[0065] Furthermore, the removal rate of Group VIII metal elements in the crude oil by the crude oil demetallizing agent is preferably ≥85%, and the removal rate of Group IIA metal elements in the crude oil is preferably ≥80%.

[0066] Furthermore, after the removal process is complete, the system is divided into an aqueous phase and an oil phase.

[0067] Furthermore, after the removal process is complete, the system is further subjected to centrifugation or gravity sedimentation to separate the precipitate in the system.

[0068] Furthermore, the centrifugation speed is 200-12000 rpm.

[0069] Furthermore, the settling time for gravity settling is 0.5-72 h.

[0070] Furthermore, during the process of removing metals from crude oil by the crude oil demetallizing agent, the reducing agent in the crude oil demetallizing agent undergoes a redox reaction with the ferric ions in the crude oil, causing a change in valence state and generating ferrous ions or iron atoms, thereby reducing the binding capacity of iron elements in crude oil with organic matter in crude oil. Subsequently, the generated ferrous ions or iron atoms undergo complexation under the synergistic effect of phosphite compounds and chelating agents to form hydrophilic compounds or precipitates. At the same time, calcium ions in crude oil also undergo complexation with phosphite compounds and chelating agents to form hydrophilic compounds or precipitates. The hydrophilic compounds are separated from the crude oil by dissolving in the aqueous phase, and the precipitates are separated from the crude oil by centrifugation or gravity sedimentation. Meanwhile, the phase transfer agent in the crude oil demetallizer promotes the reaction between metal ions and the crude oil demetallizer at the interface between the aqueous and oil phases, thus accelerating the reaction rate.

[0071] Furthermore, the organic compounds in the crude oil that are bound to iron include, but are not limited to, saturated carboxylic acids, unsaturated carboxylic acids, phenolic hydroxyl groups, nitrogen-containing compounds, and sulfur-containing compounds.

[0072] The beneficial effects of this invention are as follows: 1. The crude oil demetallizing agent provided by this invention comprises, by weight, the following components and their corresponding contents: phosphite compounds: 5-60 parts by weight; reducing agent: 0.05-30 parts by weight; chelating agent: 1-50 parts by weight; phase transfer agent: 1-30 parts by weight; solvent: 5-50 parts by weight; the crude oil demetallizing agent is used to remove metal ions M from crude oil. n+ The metal ion M n+ The metal ions are one or more metal elements from Group VIII and Group IIA, where n is an integer greater than or equal to 1; the crude oil demetallizing agent achieves a removal rate of up to 100% for Group VIII metal elements and up to 83% for Group IIA metal elements in the crude oil; 2. The crude oil demetallizing agent provided by this invention can effectively reduce the metal content in oils, reducing or avoiding problems such as catalyst poisoning and scaling caused by the presence of metals during oil production, processing, and transportation. During the demetallization process, the "phosphite compounds," "reducing agents," and "chelating agents" in the crude oil demetallizing agent work synergistically. During the removal of metals from the crude oil, the reducing agent in the crude oil demetallizing agent undergoes a redox reaction with the ferric ions in the crude oil, causing a change in valence state and generating ferrous ions or iron atoms. This reduces the binding capacity of iron elements in the crude oil with organic matter. The subsequently generated ferrous ions... Iron ions or iron atoms undergo complexation with phosphite compounds and chelating agents to form hydrophilic compounds or precipitates. Simultaneously, calcium ions in crude oil also undergo complexation with phosphite compounds and chelating agents to form hydrophilic compounds or precipitates. The hydrophilic compounds are separated from the crude oil by dissolving in the aqueous phase, and the precipitates are separated from the crude oil by centrifugation or gravity sedimentation. Meanwhile, the "solvent" is used to dissolve the remaining components, ensuring that the crude oil demetallizing agent is a homogeneous and stable liquid, facilitating subsequent addition and metering for industrial applications. The "phase transfer agent" can improve the reaction efficiency between the components in the crude oil demetallizing agent and the metal elements in the petroleum. 3. The crude oil demetallizing agent preparation method of the present invention is simple, and the process of removing metals from crude oil is also very consistent, that is, the reaction temperature and pressure are low, and the amount of chemical reagents used is smaller. 4. Compared with the existing technology, the present invention does not require an electro-desalting device, but only a mechanical stirring and mixing device and static sedimentation or centrifugal separation to achieve the demetallization effect of crude oil. Detailed Implementation

[0073] Examples 1-7 are crude oil demetallizing agents and their preparation methods, and Test Examples 1-7 are tests on the removal of metals from crude oil by the crude oil demetallizing agents in Examples 1-4.

[0074] Example 1 This embodiment provides a crude oil demetallizing agent and its preparation method: The crude oil demetallizing agent comprises the following components by weight, and the corresponding content of each component is as follows: Phosphorous acid: 40 parts by weight; L-Ascorbic acid: 5 parts by weight; Phosphoric acid: 25 parts by weight; Polyethylene glycol (PEG-600): 10 parts by weight; Water: 20 parts by weight; The preparation method is as follows: phosphorous acid, L-ascorbic acid, phosphoric acid, polyethylene glycol (PEG-600) and water are added to a stirred tank, the mixing temperature is raised to 30°C, and the mixture is stirred for 5 minutes at a stirring speed of 400 rpm to obtain a uniformly mixed crude oil demetallizing agent.

[0075] Example 2 This embodiment provides a crude oil demetallizing agent and its preparation method: The crude oil demetallizing agent comprises the following components by weight, and the corresponding content of each component is as follows: Phosphorous acid: 10 parts by weight; L-Ascorbic acid: 5 parts by weight; Phosphoric acid: 25 parts by weight; Polyethylene glycol (PEG-600): 10 parts by weight; Water: 50 parts by weight; The preparation method is as follows: phosphorous acid, L-ascorbic acid, phosphoric acid, polyethylene glycol (PEG-600) and water are added to a stirred tank, the mixing temperature is raised to 30°C, and the mixture is stirred for 5 minutes at a stirring speed of 400 rpm to obtain a uniformly mixed crude oil demetallizing agent.

[0076] Example 3 This embodiment provides a crude oil demetallizing agent and its preparation method: The crude oil demetallizing agent comprises the following components by weight, and the corresponding content of each component is as follows: Triphenyl phosphite: 40 parts by weight; L-Ascorbic acid: 5 parts by weight; Phosphoric acid: 25 parts by weight; Polyethylene glycol (PEG-600): 10 parts by weight; Water: 25 parts by weight; The preparation method is as follows: Triphenyl phosphite, L-ascorbic acid, phosphoric acid, polyethylene glycol (PEG-600), and water are added to a stirred tank, the mixing temperature is raised to 30°C, and the mixture is stirred for 5 minutes at a stirring speed of 400 rpm to obtain a uniformly mixed crude oil demetallizing agent.

[0077] Example 4 This embodiment provides a crude oil demetallizing agent and its preparation method: The crude oil demetallizing agent comprises the following components by weight, and the corresponding content of each component is as follows: Phosphorous acid: 40 parts by weight; L-Ascorbic acid: 5 parts by weight; Hydroxyethylidene diphosphonic acid (HEDP): 25 parts by weight; Polyethylene glycol (PEG-600): 10 parts by weight; Water: 20 parts by weight; The preparation method is as follows: phosphorous acid, L-ascorbic acid, hydroxyethylidene diphosphonic acid (HEDP), polyethylene glycol (PEG-600), and water are added to a stirred tank, the mixing temperature is raised to 30°C, and the mixture is stirred for 5 minutes at a stirring speed of 400 rpm to obtain a uniformly mixed crude oil demetallizing agent.

[0078] Example 5 This embodiment provides a crude oil demetallizing agent and its preparation method: The crude oil demetallizing agent comprises the following components by weight, and the corresponding content of each component is as follows: Phosphorous acid: 40 parts by weight; Oxalic acid dihydrate: 5 parts by weight; Aminotrimethylenephosphonic acid (ATMP): 25 parts by weight; Polyethylene glycol (PEG-600): 10 parts by weight; Water: 20 parts by weight; The preparation method is as follows: phosphorous acid, oxalic acid dihydrate, aminotrimethylene phosphonic acid (ATMP), polyethylene glycol (PEG-600), and water are added to a stirred tank, the mixing temperature is raised to 30°C, and the mixture is stirred for 5 minutes at a stirring speed of 400 rpm to obtain a uniformly mixed crude oil demetallizing agent.

[0079] Example 6 This embodiment provides a crude oil demetallizing agent and its preparation method: The crude oil demetallizing agent comprises the following components by weight, and the corresponding content of each component is as follows: Trimethyl phosphite: 30 parts by weight; Sodium sulfite: 8 parts by weight; Triethylenetetramine: 20 parts by weight; Polyethylene glycol (PEG-400): 12 parts by weight; Water: 30 parts by weight; The preparation method is as follows: trimethyl phosphite, sodium sulfite, triethylenetetramine, polyethylene glycol (PEG-400), and water are added to a stirred tank, the mixing temperature is raised to 30°C, and the mixture is stirred for 5 minutes at a stirring speed of 400 rpm to obtain a uniformly mixed crude oil demetallizing agent.

[0080] Example 7 This embodiment provides a crude oil demetallizing agent and its preparation method: The crude oil demetallizing agent comprises the following components by weight, and the corresponding content of each component is as follows: Dimethyl phosphite: 20 parts by weight; D-isoascorbic acid: 8 parts by weight; Hydrolyzed polymaleic anhydride (HPMA): 20 parts by weight; Polyethylene glycol monomethyl ether: 30 parts by weight; Water: 22 parts by weight; The preparation method is as follows: Dimethyl phosphite, D-isoascorbic acid, hydrolyzed polymaleic anhydride (HPMA), polyethylene glycol monomethyl ether, and water are added to a stirred tank, the mixing temperature is raised to 30°C, and the mixture is stirred for 5 minutes at a stirring speed of 400 rpm to obtain a uniformly mixed crude oil demetallizing agent.

[0081] Test Example 1 This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 1 to demetallate crude oil.

[0082] The crude oil in this test example contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0083] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Example 1 is added to the crude oil at a rate of 200mg / kg of the total crude oil weight, and 4mL of distilled water and 20ppm of demulsifier polyoxyethylene polyoxypropylene octadecyl alcohol ether are added to the system to remove the metals from the crude oil. The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase, and the iron and calcium content in the oil phase is measured. The metal removal rate is then calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this test example, the removal rate of iron was 85.7%, and the removal rate of calcium was 80.3%.

[0084] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0085] Test Example 2 This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 1 to demetallate crude oil. The difference from Test Example 1 is that the crude oil demetallizing agent was added at a rate of 50 mg / kg of the total crude oil weight; all other test conditions were the same as in Test Example 1.

[0086] In this test example, the removal rate of iron was 64.0%, and the removal rate of calcium was 71.8%.

[0087] Test Example 3 This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 1 to demetallate crude oil. The difference from Test Example 1 is that the crude oil demetallizing agent was added at a rate of 800 mg / kg of the total crude oil weight; all other test conditions were the same as in Test Example 1.

[0088] In this test example, the removal rate of iron was 85.7%, and the removal rate of calcium was 83.1%.

[0089] Test Example 4 This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 1 to demetallate crude oil. The difference from Test Example 1 is that the crude oil demetallizing agent was added at a rate of 2000 mg / kg of the total weight of the crude oil; all other test conditions were the same as in Test Example 1.

[0090] In this test example, the removal rate of iron was 100.0%, and the removal rate of calcium was 81.0%.

[0091] Test Example 5 This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 2 to demetallate crude oil.

[0092] The crude oil in this test example contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0093] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Example 1 is added to the crude oil at a rate of 200mg / kg of the total crude oil weight, and 4mL of distilled water and 20ppm of demulsifier polyoxyethylene polyoxypropylene octadecyl alcohol ether are added to the system to remove the metals from the crude oil. The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase, and the iron and calcium content in the oil phase is measured. The metal removal rate is then calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this test example, the removal rate of iron was 73.7%, and the removal rate of calcium was 76.8%.

[0094] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0095] Test Example 6 This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 3 to demetallate crude oil.

[0096] The crude oil in this test example contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0097] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Example 1 is added to the crude oil at a rate of 200mg / kg of the total crude oil weight, and 4mL of distilled water and 20ppm of demulsifier polyoxyethylene polyoxypropylene octadecyl alcohol ether are added to the system to remove the metals from the crude oil. The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase, and the iron and calcium content in the oil phase is measured. The metal removal rate is then calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this test example, the removal rate of iron was 68.0%, and the removal rate of calcium was 77.4%.

[0098] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0099] Test Example 7 This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 4 to demetallate crude oil.

[0100] The crude oil in this test example contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0101] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Example 1 is added to the crude oil at a rate of 200mg / kg of the total crude oil weight, and 4mL of distilled water and 20ppm of demulsifier polyoxyethylene polyoxypropylene octadecyl alcohol ether are added to the system to remove the metals from the crude oil. The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase, and the iron and calcium content in the oil phase is measured. The metal removal rate is then calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this test example, the removal rate of iron was 91.4%, and the removal rate of calcium was 83.8%.

[0102] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0103] Test Example 8 This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 5 to demetallate crude oil.

[0104] The crude oil in this test example contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0105] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Example 1 is added to the crude oil at a rate of 200mg / kg of the total crude oil weight, and 4mL of distilled water and 20ppm of demulsifier polyoxyethylene polyoxypropylene octadecyl alcohol ether are added to the system to remove the metals from the crude oil. The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase, and the iron and calcium content in the oil phase is measured. The metal removal rate is then calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this test example, the removal rate of iron was 82.4%, and the removal rate of calcium was 85.7%.

[0106] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0107] Test Example 9 This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 6 to demetallate crude oil.

[0108] The crude oil in this test example contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0109] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Example 1 is added to the crude oil at a rate of 200mg / kg of the total weight of the crude oil, and 4mL of distilled water and 20ppm of demulsifier are added to the system to remove the metals from the crude oil; The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase. The iron and calcium content in the oil phase is measured, and the metal removal rate is calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this test example, the removal rate of iron was 81.1%, and the removal rate of calcium was 78.9%.

[0110] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0111] Test Case 10 This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 7 to demetallate crude oil.

[0112] The crude oil in this test example contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0113] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Example 1 is added to the crude oil at a rate of 200mg / kg of the total weight of the crude oil, and 4mL of distilled water and 20ppm of demulsifier are added to the system to remove the metals from the crude oil; The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase. The iron and calcium content in the oil phase is measured, and the metal removal rate is calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this test example, the removal rate of iron was 72.6%, and the removal rate of calcium was 80.3%.

[0114] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0115] Comparative Example 1 Existing technology: 40g trimethyl phosphite, 10g HEDP, 10g PEG-600 and 15g benzyl alcohol are mixed with 225g water and placed in a stirring vessel. The stirring vessel is heated to a mixing temperature of 30℃, the stirring equipment is turned on and the speed is adjusted to 400rpm, and the mixing time is 10min to obtain a mixture.

[0116] The mixture was placed in an emulsifier and heated to an emulsification temperature of 35°C. 25g of tetrahydronaphthalene was added, and the emulsifier was turned on and the speed was adjusted to 2000rpm. The emulsification time was 22min. The mixture was mixed evenly to obtain composition A1, which has the function of removing heavy metals from hydrocarbon oils.

[0117] Comparative Example 2 This comparative example, compared to the embodiment, does not contain a reducing agent. The demetallizing agent, by weight, comprises the following components, and the corresponding content of each component is as follows: Phosphorous acid: 40 parts by weight; Phosphoric acid: 25 parts by weight; Polyethylene glycol (PEG-600): 10 parts by weight; Water: 25 parts by weight; The preparation method is as follows: phosphorous acid, phosphoric acid, polyethylene glycol (PEG-600), and water are added to a stirred tank, the mixing temperature is raised to 30°C, and the mixture is stirred for 5 minutes at a stirring speed of 400 rpm to obtain a uniformly mixed demetallizing agent.

[0118] Comparative Example 3 This comparative example, compared to the embodiment, does not contain a chelating agent. The demetallizing agent, by weight, comprises the following components, and the corresponding content of each component is as follows: Phosphorous acid: 40 parts by weight; L-Ascorbic acid: 5 parts by weight; Polyethylene glycol (PEG-600): 10 parts by weight; Water: 45 parts by weight; The preparation method is as follows: phosphorous acid, L-ascorbic acid, polyethylene glycol (PEG-600) and water are added to a stirred tank, the mixing temperature is raised to 30°C, and the mixture is stirred for 5 minutes at a stirring speed of 400 rpm to obtain a uniformly mixed metallizing agent.

[0119] Comparative Example 4 This comparative example, compared to the examples, does not contain any phosphorous acid compounds. The demetallizing agent, by weight, comprises the following components, and the corresponding amounts of each component are as follows: L-Ascorbic acid: 5 parts by weight; Hydroxyethylidene diphosphonic acid (HEDP): 25 parts by weight Polyethylene glycol (PEG-600): 10 parts by weight; Water: 60 parts by weight; The preparation method is as follows: phosphoric acid, L-ascorbic acid, polyethylene glycol (PEG-600) and water are added to a stirred tank, the mixing temperature is raised to 30°C, and the mixture is stirred for 5 minutes at a stirring speed of 400 rpm to obtain a uniformly mixed demetallizing agent.

[0120] Comparative Test Example 1 Compared to Test Example 1, this comparative test case does not add any demetallizing agent to the crude oil. Specifically: The crude oil in this comparative test case contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0121] Based on a total weight of 50g crude oil, 4mL of distilled water and 20ppm of demulsifier polyoxyethylene polyoxypropylene octadecyl alcohol ether were added to the crude oil, and the metals in the crude oil were stirred. The stirring temperature was 130℃, the pressure was controlled at ≤1MPa, and the time was 60min; After stirring, the system was centrifuged to separate the aqueous phase. The iron and calcium content in the oil phase was measured, and the metal removal rate was calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this comparative test example, the removal rate of iron was 32.0%, and the removal rate of calcium was 52.8%.

[0122] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0123] Comparative Test Example 2 This comparative test example demonstrates the use of the demetallizing agent prepared in Comparative Example 1 to demetallate crude oil.

[0124] The crude oil in this comparative test case contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0125] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Comparative Example 1 is added to the crude oil at a rate of 2000mg / kg of the total weight of the crude oil, and 4mL of distilled water and 20ppm of demulsifier are added to the system to remove the metals from the crude oil; The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase, and the iron and calcium content in the oil phase is measured. The metal removal rate is then calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this comparative test, the removal rate of iron was 80.0%, and the removal rate of calcium was 70.4%.

[0126] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0127] Comparative Test Case 3 This comparative test example demonstrates the use of the demetallizing agent prepared in Comparative Example 2 to demetallate crude oil.

[0128] The crude oil in this comparative test case contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0129] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Comparative Example 2 is added to the crude oil at a rate of 200mg / kg of the total weight of the crude oil, and 4mL of distilled water and 20ppm of demulsifier are added to the system to remove the metals from the crude oil; The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase, and the iron and calcium content in the oil phase is measured. The metal removal rate is then calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this comparative test, the removal rate of iron was 44.6%, and the removal rate of calcium was 79.6%.

[0130] Comparative Test Case 4 This comparative test example demonstrates the use of the demetallizing agent prepared in Comparative Example 3 to demetallate crude oil.

[0131] The crude oil in this comparative test case contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0132] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Comparative Example 2 is added to the crude oil at a rate of 200mg / kg of the total weight of the crude oil, and 4mL of distilled water and 20ppm of demulsifier are added to the system to remove the metals from the crude oil; The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase, and the iron and calcium content in the oil phase is measured. The metal removal rate is then calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this comparative test, the removal rate of iron was 54.9%, and the removal rate of calcium was 61.3%.

[0133] Comparative Test Example 5 This comparative test example demonstrates the use of the demetallizing agent prepared in Comparative Example 4 to demetallate crude oil.

[0134] The crude oil in this comparative test case contains 17.5 mg / kg of Group VIII iron and 14.2 mg / kg of Group IIA calcium.

[0135] The crude oil demetallization method is as follows: based on the total weight of 50g crude oil, the crude oil demetallization agent described in Comparative Example 2 is added to the crude oil at a rate of 200mg / kg of the total weight of the crude oil, and 4mL of distilled water and 20ppm of demulsifier are added to the system to remove the metals from the crude oil; The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min; After the removal process is complete, the system is centrifuged to separate the aqueous phase, and the iron and calcium content in the oil phase is measured. The metal removal rate is then calculated using the following formula: Metal removal rate = {[Content of a certain metal in the oil before demetallization (mg / kg) - Content of a certain metal in the oil after demetallization (mg / kg)] ÷ Content of a certain metal in the oil before demetallization (mg / kg)} × 100%; In this comparative test example, the removal rate of iron was 67.4%, and the removal rate of calcium was 69.0%.

[0136] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0137] The metal element content and metal removal rate of the crude oil after demetallization obtained in Examples 1-7 and Comparative Examples 1-3 of this invention are shown in Table 1.

[0138] Table 1. Metal element content and metal removal rate of crude oil after demetallization

[0139] The difference between Examples 1-7 and Comparative Example 1 is the dosage of the demetallizing agent. Experimental results show that a demetallizing agent dosage of 200 mg / kg achieves a good demetallization effect while maintaining cost-effectiveness. A demetallizing agent dosage of 100-800 mg / kg is the preferred embodiment of this invention.

[0140] The difference between Example 2 and Example 1 is the content of phosphorous compound in the demetallizing agent. Experimental results show that a phosphorous compound content of 20-40 parts by weight in the demetallizing agent is a preferred embodiment of the present invention.

[0141] The difference between Example 6 and Example 1 is the phosphorous acid compound used in the demetallizing agent. Experimental results show that selecting phosphorous acid as the phosphorous acid compound is a preferred embodiment of this invention.

[0142] The difference between Example 4 and Example 1 is the chelating agent used in the demetallizing agent. Experimental results show that selecting either phosphoric acid or hydroxyethylidene diphosphonic acid (HEDP) as the chelating agent is a preferred embodiment of this invention.

[0143] Comparing Example 4 with Comparative Example 2, it can be seen that the simultaneous presence of phosphite compounds and reducing agents can efficiently remove metals from crude oil.

[0144] The difference between Comparative Example 3 and Example 1 is the presence or absence of a chelating agent. Experimental results show that the chelating agent is an essential component of the crude oil demetallizing agent in this invention.

[0145] The difference between Comparative Example 4 and Example 4 is the presence or absence of a phosphorous acid compound. Experimental results show that phosphorous acid compounds are an essential component of the demetallizing agent in this invention.

[0146] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A crude oil demetallizing agent, characterized in that, The crude oil demetallizing agent comprises the following components by weight, and the corresponding content of each component is as follows: Phosphorous compounds: 5-60 parts by weight; Reducing agent: 0.05-30 parts by weight; Chelating agent: 1-50 parts by weight; Phase transfer agent: 1-30 parts by weight; Solvent: 5-50 parts by weight; The structural formulas of the phosphorous compounds mentioned above are shown in Formula 1 and / or Formula 2: 、 ， R1, R2, and R3 are independently H, or C1-C6 straight-chain or branched alkyl groups, or C6-C6... 12 One or more of the aryl groups; The crude oil demetallizing agent is used to remove metal ions M from crude oil. n+ The metal ion M n+ n represents the metal ion corresponding to one or more metallic elements in Group VIII and Group IIA, where n is an integer greater than or equal to 1.

2. The crude oil demetallizing agent according to claim 1, characterized in that, The phosphorous compounds are one or more of phosphorous acid, phosphites, and phosphite esters.

3. The crude oil demetallizing agent according to claim 1, characterized in that, The reducing agent is one or more of the following: reducing elemental metals, reducing gases, organic acids and their salts, and inorganic salts and their complex salts.

4. The crude oil demetallizing agent according to claim 1, characterized in that, The chelating agent has a structural formula including, but not limited to, one or more of the following: carboxyl, phosphate, amino, imino, and hyponitro groups.

5. The crude oil demetallizing agent according to claim 1, characterized in that, The phase transfer agent is one or more of polyethylene glycol, etherified products of polyethylene glycol, and esterified products of polyethylene glycol.

6. The crude oil demetallizing agent according to claim 1, characterized in that, The solvent is water or a non-aqueous solvent.

7. A method for preparing the crude oil demetallizing agent according to any one of claims 1-6, characterized in that, Mix the phosphorous compound, reducing agent, chelating agent, phase transfer agent and solvent evenly.

8. A method for demetallizing crude oil, characterized in that, The method involves using the crude oil demetallizing agent according to any one of claims 1-6 to remove metals from crude oil.

9. The crude oil demetallization method according to claim 8, characterized in that, The crude oil demetallization method specifically involves adding the crude oil demetallizing agent to the crude oil at a rate of 10-2000 mg / kg of the total crude oil weight, based on the total weight of the crude oil, and adding washing water and demulsifier to the system to remove the metals from the crude oil.

10. The crude oil demetallization method according to claim 8, characterized in that, The crude oil demetallizing agent has a removal rate of ≥64% for Group VIII metals and a removal rate of ≥70% for Group IIA metals in the crude oil.

Images