A crude oil demetallizing agent, a preparation method and a crude oil demetallizing method

Abstract

The present application relates to the technical field of crude oil metal removal, and particularly relates to a crude oil demetallization agent, a preparation method thereof and a crude oil demetallization method. According to weight parts, the crude oil demetallization agent comprises the following components and the corresponding content of each component: phosphorous acid compound: 5-60 weight parts; reducing agent: 0.05-30 weight parts; chelating agent: 1-50 weight parts; phase transfer agent: 1-30 weight parts; solvent: 5-50 weight parts. The crude oil demetallization agent is used to remove metal ions M n+ in crude oil, the metal ions M n+ are metal ions corresponding to one or more metal elements in group VIII and group IIA, the removal rate of the crude oil demetallization agent to the metal elements in group VIII in the crude oil is greater than or equal to 64%, and the removal rate of the crude oil demetallization agent to the metal elements in group IIA in the crude oil is greater 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 of 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 with the effect of removing heavy metals in hydrocarbon oil, and a preparation method and application thereof. The composition contains a metal removal agent, a hydrogen donor, a chelating agent, a phase transfer agent and a solvent. The composition contains 15-45 wt% of the metal removal 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, based on the total weight of the composition. The metal removal agent is a substance capable of reacting with nickel and vanadium in the hydrocarbon oil. However, when the composition is used to remove calcium and iron elements, the usage amount needs to be greatly increased, i.e. the cost is increased, and it is not suitable for popularization.

[0009] Based on the above, there is a technical problem in the prior art that crude oil metal removal agents cannot simultaneously and efficiently remove calcium and iron, and simultaneously achieve low dosage of the crude oil metal removal agent, mild removal conditions, and high metal removal rate. SUMMARY

[0010] To solve the above technical problems, the present application provides a crude oil metal removal agent, which comprises the following components and the corresponding contents of each component, in parts by weight:

[0011] Phosphorous acid compound: 5-60 parts by weight;

[0012] Reducing agent: 0.05-30 parts by weight;

[0013] Chelating agent: 1-50 parts by weight;

[0014] Phase transfer agent: 1-30 parts by weight;

[0015] Solvent: 5-50 parts by weight;

[0016] The structure of the phosphorous acid compound is shown in formula 1 and / or formula 2:

[0017] 、 ,

[0018] R1, R2, R3 are independently H, or one or more of C1-C6 linear or branched alkyl, or C6-C 12 aryl;

[0019] The crude oil metal removal agent is used to remove metal ions M n+ in the crude oil, wherein the metal ions M n+ are metal ions corresponding to one or more metal elements in Group VIII and Group IIA, and n is an integer greater than or equal to 1.

[0020] Further, the phosphorous acid compound is one or more of phosphorous acid, phosphite, and phosphonite.

[0021] Further, the phosphite includes, but is not limited to, one or more of 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 tritolyl phosphite.

[0022] Further, the reducing agent is one or more of a reducing metal element, a reducing gas, an organic acid and its salt, an inorganic salt and its complex salt.

[0023] Further, the reducing metal element includes, but is not limited to, one or more of iron powder, zinc powder, and aluminum powder.

[0024] Further, the reducing gas includes, but is not limited to, hydrogen and sulfur dioxide.

[0025] Further, the organic acid and its salt includes, but is not limited to, one or more of L-ascorbic acid and its salt, D-isoascorbic acid and its salt, and oxalic acid and its salt.

[0026] Further, the cation of the inorganic salt and its complex salt includes, but is not limited to, one or more of sodium ion and ferrous ion.

[0027] Further, the anion of the inorganic salt and its complex salt includes, but is not limited to, one or more of sulfite, bisulfite, sulfate, and chloride.

[0028] Further, the inorganic salt and its complex salt includes, but is not limited to, one or more of sodium sulfite, sodium bisulfite, ferrous sulfate, ferrous ammonium sulfate, and ferrous chloride.

[0029] Further, the chelating agent includes, but is not limited to, one or more of carboxyl, phosphoric acid group, amino group, imino group, and nitroso group in its structural formula.

[0030] Further, the chelating agent includes, but is not limited to, one or more of phosphoric acid, amino trimethylene phosphonic acid (ATMP), hydroxy ethylene diphosphonic acid (HEDP), hydrolyzed poly maleic anhydride (HPMA), polyacrylic acid (PAA), ethylenediaminetetraacetic acid (EDTA) and its salt, edetic acid and its salt, iminodisuccinic acid and its salt, triethylene tetramine, tetraethylene pentamine, and ethylenediamine.

[0031] Further, when the chelating agent is hydrolyzed polymaleic anhydride (HPMA), its structural group has a chelating effect with metal ions as shown in formula 3:

[0032] Formula 3

[0033]

[0034] wherein M n+ is a metal ion corresponding to one or more metal elements of Group VIII and Group IIA metals, and n is an integer greater than or equal to 1.

[0035] Further, when the chelating agent is phosphoric acid, amino-tris-methylene phosphonic acid (ATMP), hydroxy-ethylene diphosphonic acid (HEDP), its structural group has a chelating effect with metal ions as shown in formula 4:

[0036] Formula 4

[0037]

[0038] In formula 4, R4 is a carbon chain with imino, nitro, hydroxyl or phosphoric acid group with C1-C5, M n+ is a metal ion corresponding to one or more metal elements of Group VIII and Group IIA metals, and n is an integer greater than or equal to 1.

[0039] Further, the phase transfer agent is one or more of polyethylene glycol, etherification product of polyethylene glycol, esterification product of polyethylene glycol.

[0040] Further, the model of polyethylene glycol is PEG-400, PEG-600.

[0041] Further, the etherification product of polyethylene glycol is polyethylene glycol monomethyl ether, polyethylene glycol diethyl ether.

[0042] Further, the esterification product of polyethylene glycol is polyethylene glycol monomethyl ether propylene ester.

[0043] Further, the solvent is water or a non-aqueous solvent.

[0044] Further, the non-aqueous solvent is one or more of an organic alcohol solvent, an organic ketone solvent, an organic ester solvent.

[0045] Further, the organic alcohol solvent is one or more of methanol, ethanol, isopropyl alcohol, benzyl alcohol.

[0046] Further, the organic ketone solvent is acetone.

[0047] Further, the organic ester solvent is an ester solvent containing carbonate.

[0048] Further, the organic ester solvent includes, but is not limited to, ethylene carbonate and propylene carbonate.

[0049] Further, the content of the phosphorous acid compound is preferably 10-50 parts by weight.

[0050] Further, the content of the reducing agent is preferably 1-15 parts by weight.

[0051] Further, the content of the chelating agent is preferably 10-30 parts by weight.

[0052] Further, the content of the phase transfer agent is preferably 5-15 parts by weight.

[0053] Further, the content of the solvent is preferably 10-30 parts by weight.

[0054] The present application also provides a preparation method of the crude oil demetallization agent, which comprises mixing the phosphorous acid compound, the reducing agent, the chelating agent, the phase transfer agent and the solvent uniformly.

[0055] Further, the mixing temperature is 20-50℃, and the mixing time is 1-30 min.

[0056] Further, the mixing rate is 200-500 rpm.

[0057] The present application also provides a crude oil demetallization method, which comprises using the crude oil demetallization agent to remove the metal in the crude oil.

[0058] Further, the metal includes, but is not limited to, one or more of the Group VIII and Group IIA metals.

[0059] Further, the content of the metal in the crude oil is 10 mg / kg or more based on the total weight of the crude oil.

[0060] Further, the content of the Group VIII metal in the crude oil is 1-50 mg / kg.

[0061] Further, the content of the Group IIA metal in the crude oil is 1-50 mg / kg.

[0062] Further, the content of the iron element in the Group VIII metal in the crude oil is 5-25 mg / kg.

[0063] Further, the content of the calcium element in the Group IIA metal in the crude oil is 10-20 mg / kg.

[0064] Further, the crude oil demetallization method is specifically: taking the total weight of the crude oil as the basis, adding the crude oil demetallization agent to the crude oil at 10-2000 mg / kg of the total weight of the crude oil, and adding washing water and a demulsifier to the system to remove the metals in the crude oil.

[0065] Further, 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.

[0066] Further, the removal temperature is 50-180℃, the pressure is ≤1 MPa, and the time is 10-300 min.

[0067] Further, the removal temperature is preferably 80-140℃.

[0068] Further, the removal time is preferably 30-240 min.

[0069] Further, the washing water accounts for 5-10 wt% of the total weight of the crude oil.

[0070] Further, the pH value of the washing water is 6-9.

[0071] Further, the washing water includes but is not limited to soft water, distilled water, and pure water, and water solvents that do not affect the effect of the crude oil demetallization agent can be used as washing water.

[0072] Further, the demulsifier accounts for 10-50 ppm of the total weight of the crude oil.

[0073] Further, the demulsifier is a non-ionic demulsifier, which is sufficient to separate the oil phase and the water phase.

[0074] Further, the demulsifier is preferably a polyether demulsifier.

[0075] Further, the demulsifier is preferably a polyoxyethylene-polyoxypropylene copolymer.

[0076] Further, the polyoxyethylene-polyoxypropylene copolymer includes but is not limited to: an alcohol-initiated polyoxypropylene-polyoxyethylene block copolymer, an amine-initiated polyoxypropylene-polyoxyethylene block copolymer, a phenol formaldehyde resin and / or phenol amine resin-initiated polyoxypropylene-polyoxyethylene block copolymer, and a toluene diisocyanate chain extender polyoxyethylene-polyoxypropylene block copolymer.

[0077] Further, the crude oil demetallization agent has a removal rate of the Group VIII metal elements in the crude oil ≥64% and a removal rate of the Group IIA metal elements in the crude oil ≥70%.

[0078] Further, the removal rate of the Group VIII metal elements in the crude oil by the crude oil demetallization agent is preferably ≥ 85%, and the removal rate of the Group IIA metal elements in the crude oil is preferably ≥ 80%.

[0079] Further, after the removal is completed, the system is divided into an aqueous phase and an oil phase.

[0080] Further, after the removal is completed, the system is further subjected to centrifugation or gravity sedimentation to separate the precipitate in the system.

[0081] Further, the rotation speed of the centrifugation is 200-12000 rpm.

[0082] Further, the standing time of the gravity sedimentation is 0.5-72 h.

[0083] Further, in the process of removing the metal in the crude oil by the crude oil demetallization agent, the reducing agent in the crude oil demetallization agent and the trivalent iron ion in the crude oil undergoes an oxidation-reduction reaction, causing a change in valence, generating divalent iron ions or iron atoms, so that the combination ability of the iron elements in the crude oil and the organic matters in the crude oil is reduced.

[0084] Then, the generated divalent iron ions or iron atoms undergo complexation under the synergistic action of the phosphorous acid compound and the chelating agent to form hydrophilic compounds or precipitate substances, and the calcium ions in the crude oil also undergo complexation with the phosphorous acid compound and the chelating agent to form hydrophilic compounds or precipitate substances, the hydrophilic compounds are separated from the crude oil by dissolving in the aqueous phase, and the precipitate is separated from the crude oil by centrifugation or gravity sedimentation.

[0085] Meanwhile, the phase transfer agent in the crude oil demetallization agent promotes the reaction of the metal ions and the crude oil demetallization agent at the interface between the aqueous phase and the oil phase, and accelerates the reaction rate.

[0086] Further, the organic matters combined with the iron elements in the crude oil include, but are not limited to, saturated carboxylic acids, unsaturated carboxylic acids, phenolic hydroxyl groups, nitrogen-containing compounds, and sulfur-containing compounds.

[0087] The beneficial effects of the present application are as follows:

[0088] 1. The crude oil demetallization agent provided by the present application comprises the following components and the corresponding contents of each component by weight parts: phosphorous acid compound: 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 demetallization agent is used to remove the metal ions M n+ in the crude oil. n+Mn+ n, M is a metal ion corresponding to one or more metal elements of Group VIII and Group IIA, n is an integer greater than or equal to 1; the removal rate of the crude oil demetallization agent for Group VIII metal elements in the crude oil is up to 100%, and the removal rate of the crude oil demetallization agent for Group IIA metal elements in the crude oil is up to 83%;

[0089] 2、The crude oil demetallization agent provided by the present application can effectively reduce the metal content in oil, and reduce or avoid problems such as catalyst poisoning and fouling caused by the presence of metal in the process of oil production, processing and transportation; in the process of demetallization, the three of the "phosphorous acid compound", "reducing agent" and "chelating agent" in the crude oil demetallization agent synergistically act, and in the process of removing the metal in the crude oil by the crude oil demetallization agent, the reducing agent in the crude oil demetallization agent and the trivalent iron ion in the crude oil undergoes an oxidation-reduction reaction, causing a change in valence, generating divalent iron ions or iron atoms, so that the combination ability of iron elements in the crude oil and organic matters in the crude oil is reduced; then the generated divalent iron ions or iron atoms undergo complexation under the synergistic action of the phosphorous acid compound and the chelating agent to form hydrophilic compounds or precipitated substances, and at the same time, the calcium ions in the crude oil also undergo complexation with the phosphorous acid compound and the chelating agent to form hydrophilic compounds or precipitated substances, the hydrophilic compounds are separated from the crude oil by dissolving in the water phase, and the precipitates are separated from the crude oil by centrifugation or gravity settling; at the same time, the "solvent" is used to dissolve the remaining components, and the use of the solvent can ensure that the crude oil demetallization agent is a uniform and stable liquid, facilitating the subsequent addition and metering for industrial use; the "phase transfer agent" can improve the reaction efficiency of each component in the crude oil demetallization agent and the metal elements in the oil;

[0090] 3、The preparation method of the crude oil demetallization agent is simple, and the process of removing the metal in the crude oil is also very consistent, that is, the reaction temperature and pressure are relatively low, and the chemical agent dosage is smaller;

[0091] 4、Compared with the prior art, the present application does not need an electric desalting device, but only needs a mechanical stirring and mixing device and a static precipitation or centrifugal separation to realize the demetallization effect of the crude oil. DETAILED DESCRIPTION

[0092] Examples 1-7 are crude oil demetallization agents and preparation methods thereof, and test examples 1-7 are tests of the removal of metal in the crude oil by the crude oil demetallization agents in examples 1-4.

[0093] Example 1

[0094] The present embodiment provides a crude oil demetallization agent and a preparation method thereof:

[0095] The crude oil demetallization agent includes the following components and the corresponding content of each component by weight:

[0096] Phosphorous acid: 40 parts by weight;

[0097] L-ascorbic acid: 5 parts by weight;

[0098] Phosphoric acid: 25 parts by weight;

[0099] Polyethylene glycol (PEG-600): 10 parts by weight;

[0100] Water: 20 parts by weight;

[0101] The preparation method is: adding phosphorous acid, L-ascorbic acid, phosphoric acid, polyethylene glycol (PEG-600), and water into a stirred tank, increasing the mixing temperature to 30°C, stirring for 5 min under the condition that the stirring speed is 400 rpm, to obtain the crude oil demetalizing agent which is uniformly mixed.

[0102] Example 2

[0103] The present example provides a crude oil demetalizing agent and a preparation method thereof:

[0104] The crude oil demetalizing agent includes the following components and the corresponding content of each component by weight parts:

[0105] Phosphorous acid: 10 parts by weight;

[0106] L-ascorbic acid: 5 parts by weight;

[0107] Phosphoric acid: 25 parts by weight;

[0108] Polyethylene glycol (PEG-600): 10 parts by weight;

[0109] Water: 50 parts by weight;

[0110] The preparation method is: adding phosphorous acid, L-ascorbic acid, phosphoric acid, polyethylene glycol (PEG-600), and water into a stirred tank, increasing the mixing temperature to 30°C, stirring for 5 min under the condition that the stirring speed is 400 rpm, to obtain the crude oil demetalizing agent which is uniformly mixed.

[0111] Example 3

[0112] The present example provides a crude oil demetalizing agent and a preparation method thereof:

[0113] The crude oil demetalizing agent includes the following components and the corresponding content of each component by weight parts:

[0114] Triphenyl phosphite: 40 parts by weight;

[0115] L-ascorbic acid: 5 parts by weight;

[0116] Phosphoric acid: 25 parts by weight;

[0117] Polyethylene glycol (PEG-600): 10 parts by weight;

[0118] Water: 25 parts by weight;

[0119] The preparation method is: adding triphenyl phosphite, L-ascorbic acid, phosphoric acid, polyethylene glycol (PEG-600) and water into a stirred tank, increasing the mixing temperature to 30°C, stirring for 5 min at a stirring speed of 400 rpm, to obtain the crude oil demetalizing agent with uniform mixing.

[0120] Example 4

[0121] The present example provides a crude oil demetalizing agent and a preparation method thereof:

[0122] The crude oil demetalizing agent includes the following components and the corresponding content of each component, in parts by weight:

[0123] Phosphorous acid: 40 parts by weight;

[0124] L-ascorbic acid: 5 parts by weight;

[0125] Hydroxyethylidene diphosphonic acid (HEDP): 25 parts by weight;

[0126] Polyethylene glycol (PEG-600): 10 parts by weight;

[0127] Water: 20 parts by weight;

[0128] The preparation method is: adding phosphorous acid, L-ascorbic acid, hydroxyethylidene diphosphonic acid (HEDP), polyethylene glycol (PEG-600) and water into a stirred tank, increasing the mixing temperature to 30°C, stirring for 5 min at a stirring speed of 400 rpm, to obtain the crude oil demetalizing agent with uniform mixing.

[0129] Example 5

[0130] The present example provides a crude oil demetalizing agent and a preparation method thereof:

[0131] The crude oil demetalizing agent includes the following components and the corresponding content of each component, in parts by weight:

[0132] Phosphorous acid: 40 parts by weight;

[0133] Oxalic acid dihydrate: 5 parts by weight;

[0134] Aminotri(methylene) phosphonic acid (ATMP): 25 parts by weight;

[0135] Polyethylene glycol (PEG-600): 10 parts by weight;

[0136] Water: 20 parts by weight;

[0137] The preparation method is: adding phosphorous acid, oxalic acid dihydrate, aminotrimethylene phosphonic acid (ATMP), polyethylene glycol (PEG-600), and water into a stirring kettle, increasing the mixing temperature to 30°C, stirring for 5 min at a stirring speed of 400 rpm, to obtain the crude oil demetalizing agent with uniform mixing.

[0138] Example 6

[0139] The present example provides a crude oil demetalizing agent and a preparation method thereof:

[0140] The crude oil demetalizing agent includes the following components and the corresponding content of each component by weight parts:

[0141] Trimethyl phosphite: 30 parts by weight;

[0142] Sodium sulfite: 8 parts by weight;

[0143] Triethylenetetramine: 20 parts by weight;

[0144] Polyethylene glycol (PEG-400): 12 parts by weight;

[0145] Water: 30 parts by weight;

[0146] The preparation method is: adding trimethyl phosphite, sodium sulfite, triethylenetetramine, polyethylene glycol (PEG-400), and water into a stirring kettle, increasing the mixing temperature to 30°C, stirring for 5 min at a stirring speed of 400 rpm, to obtain the crude oil demetalizing agent with uniform mixing.

[0147] Example 7

[0148] The present example provides a crude oil demetalizing agent and a preparation method thereof:

[0149] The crude oil demetalizing agent includes the following components and the corresponding content of each component by weight parts:

[0150] Dimethyl phosphite: 20 parts by weight;

[0151] D-erythorbic acid: 8 parts by weight;

[0152] Hydrolyzed polymaleic anhydride (HPMA): 20 parts by weight;

[0153] Polyethylene glycol monomethyl ether: 30 parts by weight;

[0154] Water: 22 parts by weight;

[0155] 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.

[0156] Test Example 1

[0157] This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 1 to demetallate crude oil.

[0158] 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.

[0159] 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.

[0160] The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min;

[0161] 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:

[0162] 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%;

[0163] In this test example, the removal rate of iron was 85.7%, and the removal rate of calcium was 80.3%.

[0164] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0165] Test Example 2

[0166] 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.

[0167] In this test example, the removal rate of iron was 64.0%, and the removal rate of calcium was 71.8%.

[0168] Test Example 3

[0169] In this test example, the removal rate of iron element was 85.7%, and the removal rate of calcium element was 83.1%.

[0170] In this test example, the removal rate of iron element was 85.7%, and the removal rate of calcium element was 83.1%.

[0171] Test Example 4

[0172] In this test example, the removal rate of iron element was 85.7%, and the removal rate of calcium element was 83.1%.

[0173] In this test example, the removal rate of iron element was 85.7%, and the removal rate of calcium element was 83.1%.

[0174] Test Example 5

[0175] In this test example, the removal rate of iron element was 85.7%, and the removal rate of calcium element was 83.1%.

[0176] In this test example, the content of Group VIII iron element in the crude oil was 17.5 mg / kg, and the content of Group IIA calcium element was 14.2 mg / kg.

[0177] The crude oil demetallization method was as follows: 50 g of crude oil was taken as a reference, and the crude oil demetallization agent in Example 1 was added to the crude oil at a dosage of 200 mg / kg of the total weight of the crude oil, 4 mL of distilled water and 20 ppm of demulsifier polyoxyethylene polyoxypropylene octadecanol ether were added to the system, and the metals in the crude oil were removed.

[0178] The removal temperature was 130°C, the pressure was controlled at ≤1 MPa, and the time was 60 min.

[0179] After the removal was completed, the system was centrifuged and the aqueous phase was separated, the content of iron element and calcium element in the oil phase was detected, and the metal removal rate was calculated according to the following formula:

[0180] Metal removal rate = {[content of a certain metal in oil before demetallization (mg / kg) - content of a certain metal in oil after demetallization (mg / kg)] ÷ content of a certain metal in oil before demetallization (mg / kg)} × 100%;

[0181] In the test example, the removal rate of iron element is 73.7%, and the removal rate of calcium element is 76.8%.

[0182] The content of the metal element is detected by an inductively coupled plasma emission spectrometer.

[0183] Test Example 6

[0184] In the test example, the removal rate of iron element is 73.7%, and the removal rate of calcium element is 76.8%.

[0185] In the test example, the content of iron element in the crude oil is 17.5 mg / kg, and the content of calcium element in the crude oil is 14.2 mg / kg.

[0186] The crude oil demetallization method is specifically as follows: 50 g of crude oil is taken as a reference, and the crude oil demetallization agent in Example 1 is added to the crude oil at 200 mg / kg of the total weight of the crude oil, and 4 mL of distilled water and 20 ppm of demulsifier polyoxyethylene polyoxypropylene octadecanol ether are added to the system to remove the metal in the crude oil.

[0187] The removal temperature is 130°C, the pressure is controlled to be ≤1 MPa, and the time is 60 min.

[0188] After the removal is completed, the system is centrifuged and the aqueous phase is separated, and the content of iron element and calcium element in the oil phase is detected, and the metal removal rate is calculated according to the following formula:

[0189] The metal removal rate is {[the content of a certain metal in the oil before demetallization (mg / kg)-the content of a certain metal in the oil after demetallization (mg / kg)]÷the content of a certain metal in the oil before demetallization (mg / kg)}×100%.

[0190] In the test example, the removal rate of iron element is 68.0%, and the removal rate of calcium element is 77.4%.

[0191] The content of the metal element is detected by an inductively coupled plasma emission spectrometer.

[0192] Test Example 7

[0193] In the test example, the removal rate of iron element is 73.7%, and the removal rate of calcium element is 76.8%.

[0194] In the test example, the content of iron element in the crude oil is 17.5 mg / kg, and the content of calcium element in the crude oil is 14.2 mg / kg.

[0195] The crude oil demetallization method is specifically as follows: 200 mg / kg of the crude oil demetallization agent in Example 1 is added to 50 g of crude oil as a whole, 4 mL of distilled water and 20 ppm of demulsifier polyoxyethylene polyoxypropylene octadecanol ether are added to the system, and the metals in the crude oil are removed;

[0196] The removal temperature is 130°C, the pressure is controlled to be ≤1 MPa, and the time is 60 min.

[0197] After the removal is completed, the system is centrifuged and the aqueous phase is separated, the content of iron and calcium elements in the oil phase is detected, and the metal removal rate is calculated according to the following formula:

[0198] The metal removal rate is {[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%.

[0199] In this test example, the removal rate of iron element is 91.4%, and the removal rate of calcium element is 83.8%.

[0200] The content of the metal element is detected by inductively coupled plasma emission spectrometer.

[0201] Test Example 8

[0202] This test example is to demetallize crude oil using the crude oil demetallization agent prepared in Example 5.

[0203] The content of the iron element in Group VIII in the crude oil in this test example is 17.5 mg / kg, and the content of the calcium element in Group IIA is 14.2 mg / kg.

[0204] The crude oil demetallization method is specifically as follows: 200 mg / kg of the crude oil demetallization agent in Example 1 is added to 50 g of crude oil as a whole, 4 mL of distilled water and 20 ppm of demulsifier polyoxyethylene polyoxypropylene octadecanol ether are added to the system, and the metals in the crude oil are removed;

[0205] The removal temperature is 130°C, the pressure is controlled to be ≤1 MPa, and the time is 60 min.

[0206] After the removal is completed, the system is centrifuged and the aqueous phase is separated, the content of iron and calcium elements in the oil phase is detected, and the metal removal rate is calculated according to the following formula:

[0207] 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%;

[0208] In this test example, the removal rate of iron was 82.4%, and the removal rate of calcium was 85.7%.

[0209] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0210] Test Example 9

[0211] This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 6 to demetallate crude oil.

[0212] 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.

[0213] 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;

[0214] The removal temperature is 130℃, the pressure is controlled at ≤1MPa, and the time is 60min;

[0215] 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:

[0216] 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%;

[0217] In this test example, the removal rate of iron was 81.1%, and the removal rate of calcium was 78.9%.

[0218] The content of the metal element was detected using an inductively coupled plasma atomic emission spectrometer.

[0219] Test Case 10

[0220] This test example demonstrates the use of the crude oil demetallizing agent prepared in Example 7 to demetallate crude oil.

[0221] The content of Group VIII iron element in the crude oil in the test example is 17.5 mg / kg, and the content of Group IIA calcium element is 14.2 mg / kg.

[0222] The crude oil demetallization method is specifically as follows: 50 g of the crude oil is taken as a basis, the crude oil demetallization agent in Example 1 is added to the crude oil at 200 mg / kg of the total weight of the crude oil, 4 mL of distilled water and 20 ppm of a demulsifier are added to the system, and the metals in the crude oil are removed.

[0223] The removal temperature is 130°C, the pressure is controlled to be ≤1 MPa, and the time is 60 min.

[0224] After the removal is completed, the system is centrifuged and the aqueous phase is separated, the content of iron element and calcium element in the oil phase is detected, and the metal removal rate is calculated according to the following formula:

[0225] The metal removal rate is {[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%.

[0226] In the test example, the removal rate of iron element is 72.6%, and the removal rate of calcium element is 80.3%.

[0227] The content of the metal element is detected by an inductively coupled plasma emission spectrometer.

[0228] Comparative Example 1

[0229] Prior art: 40 g of trimethyl phosphite, 10 g of HEDP, 10 g of PEG-600 and 15 g of benzyl alcohol are mixed with 225 g of water in a stirred tank, the stirred tank is heated to a mixing temperature of 30°C, the stirring device is turned on to a rotation speed of 400 rpm, and the mixing time is 10 min to obtain a mixture.

[0230] The mixture is placed in an emulsifier, heated to an emulsification temperature of 35°C, 25 g of tetrahydronaphthalene is added, the emulsifier is turned on to a rotation speed of 2000 rpm, and the emulsification time is 22 min, and the mixture is uniformly mixed to obtain a composition A1 having the effect of removing heavy metals in hydrocarbon oils.

[0231] Comparative Example 2

[0232] In this comparative example, no reducing agent is added relative to the examples, and the demetallization agent includes the following components by weight, and the content of each component is as follows:

[0233] Phosphorous acid: 40 parts by weight;

[0234] Phosphoric acid: 25 parts by weight;

[0235] Polyethylene glycol (PEG-600): 10 parts by weight;

[0236] Water: 25 parts by weight;

[0237] The preparation method is: adding phosphorous acid, phosphoric acid, polyethylene glycol (PEG-600) and water into the stirred tank, increasing the mixing temperature to 30°C, stirring for 5 min under the condition that the stirring speed is 400 rpm, to obtain the demetalizing agent which is uniformly mixed.

[0238] Comparative Example 3

[0239] In this comparative example, no chelating agent is added, and the demetalizing agent includes the following components by weight, and the content of each component is:

[0240] Phosphorous acid: 40 parts by weight;

[0241] L-ascorbic acid: 5 parts by weight;

[0242] Polyethylene glycol (PEG-600): 10 parts by weight;

[0243] Water: 45 parts by weight;

[0244] The preparation method is: adding phosphorous acid, L-ascorbic acid, polyethylene glycol (PEG-600) and water into the stirred tank, increasing the mixing temperature to 30°C, stirring for 5 min under the condition that the stirring speed is 400 rpm, to obtain the demetalizing agent which is uniformly mixed.

[0245] Comparative Example 4

[0246] In this comparative example, no phosphorous acid compound is added, and the demetalizing agent includes the following components by weight, and the content of each component is:

[0247] L-ascorbic acid: 5 parts by weight;

[0248] Hydroxyethylidene diphosphonic acid (HEDP): 25 parts by weight

[0249] Polyethylene glycol (PEG-600): 10 parts by weight;

[0250] Water: 60 parts by weight;

[0251] The preparation method is: adding phosphorous acid, L-ascorbic acid, polyethylene glycol (PEG-600) and water into the stirred tank, increasing the mixing temperature to 30°C, stirring for 5 min under the condition that the stirring speed is 400 rpm, to obtain the demetalizing agent which is uniformly mixed.

[0252] Comparative Test Example 1

[0253] The comparative test example is relative to test example 1, and no demetalizing agent is added to the crude oil, specifically:

[0254] The content of group VIII iron element in the crude oil in the comparative test example is 17.5 mg / kg, and the content of group IIA calcium element is 14.2 mg / kg.

[0255] 4 mL of distilled water and 20 ppm of demulsifier polyoxyethylene polyoxypropylene octadecanol ether are added to the crude oil based on the total weight of 50 g of the crude oil, and the metals in the crude oil are stirred;

[0256] The stirring temperature is 130°C, the pressure is controlled to be ≤1 MPa, and the time is 60 min;

[0257] After the stirring is completed, the system is centrifuged and the aqueous phase is separated, and the content of iron element and calcium element in the oil phase is detected, and the metal removal rate is calculated according to the following formula:

[0258] Metal removal rate = {[content of a certain metal in oil before demetalization (mg / kg) - content of a certain metal in oil after demetalization (mg / kg)] ÷ content of a certain metal in oil before demetalization (mg / kg)} × 100%;

[0259] In the comparative test example, the removal rate of the iron element is 32.0%, and the removal rate of the calcium element is 52.8%.

[0260] The content of the metal element is detected by inductively coupled plasma emission spectrometer.

[0261] Comparative test example 2

[0262] The comparative test example is to demetalize the crude oil using the demetalizing agent prepared in comparative example 1.

[0263] The content of group VIII iron element in the crude oil in the comparative test example is 17.5 mg / kg, and the content of group IIA calcium element is 14.2 mg / kg.

[0264] The crude oil demetalization method is specifically: based on the total weight of 50 g of the crude oil, the crude oil demetalizing agent in comparative example 1 is added to the crude oil at 2000 mg / kg of the total weight of the crude oil, and 4 mL of distilled water and 20 ppm of demulsifier are added to the system, and the metals in the crude oil are removed;

[0265] The removal temperature is 130°C, the pressure is controlled to be ≤1 MPa, and the time is 60 min;

[0266] After the removal is finished, the system is centrifuged and the water phase is separated, the content of iron element and calcium element in the oil phase is detected, and the metal removal rate is calculated according to the following formula:

[0267] Metal removal rate = {[content of a certain metal in oil before demetallization (mg / kg) - content of a certain metal in oil after demetallization (mg / kg)] ÷ content of a certain metal in oil before demetallization (mg / kg)} × 100%;

[0268] In this comparative test example, the removal rate of iron element is 80.0%, and the removal rate of calcium element is 70.4%.

[0269] The content of the metal element is detected by inductively coupled plasma emission spectrometer.

[0270] Comparative Test Example 3

[0271] In this comparative test example, the demetallization agent prepared in Comparative Example 2 is used to demetallize crude oil.

[0272] In this comparative test example, the content of Group VIII iron element in the crude oil is 17.5 mg / kg, and the content of Group IIA calcium element is 14.2 mg / kg.

[0273] The specific method for demetallizing the crude oil is: based on the total weight of 50 g of crude oil, the crude oil demetallization agent in Comparative Example 2 is added to the crude oil at 200 mg / kg of the total weight of the crude oil, and 4 mL of distilled water and 20 ppm of demulsifier are added to the system to remove the metal in the crude oil;

[0274] The removal temperature is 130°C, the pressure is controlled to be ≤1 MPa, and the time is 60 min;

[0275] After the removal is finished, the system is centrifuged and the water phase is separated, the content of iron element and calcium element in the oil phase is detected, and the metal removal rate is calculated according to the following formula:

[0276] Metal removal rate = {[content of a certain metal in oil before demetallization (mg / kg) - content of a certain metal in oil after demetallization (mg / kg)] ÷ content of a certain metal in oil before demetallization (mg / kg)} × 100%;

[0277] In this comparative test example, the removal rate of iron element is 44.6%, and the removal rate of calcium element is 79.6%.

[0278] Comparative Test Example 4

[0279] In this comparative test example, the demetallization agent prepared in Comparative Example 3 is used to demetallize crude oil.

[0280] The content of Group VIII iron element in the crude oil in this comparative test example was 17.5 mg / kg, and the content of Group IIA calcium element was 14.2 mg / kg.

[0281] The crude oil demetallization method was specifically as follows: the crude oil demetallization agent in Comparative Example 2 was added to the crude oil at 200 mg / kg of the total weight of the crude oil, and 4 mL of distilled water and 20 ppm of a demulsifier were added to the system, so as to remove the metals in the crude oil;

[0282] The removal temperature was 130°C, the pressure was controlled to be ≤1 MPa, and the time was 60 min;

[0283] After the removal was completed, the system was centrifuged and the aqueous phase was separated, the content of iron element and calcium element in the oil phase was detected, and the metal removal rate was calculated according to the following formula:

[0284] The metal removal rate was {[the content of a certain metal in the oil before demetallization (mg / kg) - the content of a certain metal in the oil after demetallization (mg / kg)] ÷ the content of a certain metal in the oil before demetallization (mg / kg)} × 100%.

[0285] In this comparative test example, the removal rate of iron element was 54.9%, and the removal rate of calcium element was 61.3%.

[0286] Comparative Test Example 5

[0287] In this comparative test example, the crude oil was demetallized using the demetallization agent prepared in Comparative Example 4.

[0288] The content of Group VIII iron element in the crude oil in this comparative test example was 17.5 mg / kg, and the content of Group IIA calcium element was 14.2 mg / kg.

[0289] The crude oil demetallization method was specifically as follows: the crude oil demetallization agent in Comparative Example 2 was added to the crude oil at 200 mg / kg of the total weight of the crude oil, and 4 mL of distilled water and 20 ppm of a demulsifier were added to the system, so as to remove the metals in the crude oil;

[0290] The removal temperature was 130°C, the pressure was controlled to be ≤1 MPa, and the time was 60 min;

[0291] After the removal was completed, the system was centrifuged and the aqueous phase was separated, the content of iron element and calcium element in the oil phase was detected, and the metal removal rate was calculated according to the following formula:

[0292] The metal removal rate is {[content of the certain metal in the oil before the metal removal (mg / kg)-content of the certain metal in the oil after the metal removal (mg / kg)]÷content of the certain metal in the oil before the metal removal (mg / kg)}×100%.

[0293] In the present comparative test example, the removal rate of the iron element is 67.4%, and the removal rate of the calcium element is 69.0%.

[0294] The content of the metal element is detected by an inductively coupled plasma emission spectrometer.

[0295] The content of the metal element in the crude oil after the metal removal and the metal removal rate in the present embodiments 1-7 and the present comparative examples 1-3 are shown in Table 1.

[0296] Table 1: Content of metal element in crude oil after metal removal and metal removal rate

[0297]

[0298] The difference between the present embodiments 1-7 and the present comparative example 1 is the amount of the metal removal agent added. According to the experimental results, it can be seen that the amount of the metal removal agent of 200 mg / kg can take into account the cost and the metal removal effect. The amount of the metal removal agent of 100-800 mg / kg is a preferred embodiment of the present application.

[0299] The difference between the present embodiment 2 and the present embodiment 1 is the content of the phosphorous acid compound in the metal removal agent. According to the experimental results, it can be seen that the content of the phosphorous acid compound in the metal removal agent of 20-40 parts by weight is a preferred embodiment of the present application.

[0300] The difference between the present embodiment 6 and the present embodiment 1 is the phosphorous acid compound used in the metal removal agent. According to the experimental results, it can be seen that the phosphorous acid compound is selected from phosphorous acid is a preferred embodiment of the present application.

[0301] The difference between the present embodiment 4 and the present embodiment 1 is the chelating agent used in the metal removal agent. According to the experimental results, it can be seen that the chelating agent is selected from one of phosphoric acid and hydroxyethylidene diphosphonic acid (HEDP) is a preferred embodiment of the present application.

[0302] It can be seen from the comparison between the present embodiment 4 and the present comparative example 2 that the simultaneous presence of the phosphorous acid compound and the reducing agent can efficiently remove the metal in the crude oil.

[0303] The difference between the present comparative example 3 and the present embodiment 1 is whether the chelating agent is added. According to the experimental results, it can be seen that the chelating agent is a necessary component of the crude oil metal removal agent in the present application.

[0304] 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.

[0305] 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 metal removal agent comprises the following components and the corresponding content of each component is as follows in parts by weight: Phosphorous acid compound: 5-60 parts by weight; the phosphorous acid compound is phosphorous acid; Reducing agent: 0.05-30 parts by weight; the reducing agent is one of L-ascorbic acid and oxalic acid dihydrate; Chelating agent: 1-50 parts by weight; the chelating agent is one of phosphoric acid, hydroxyethylidene diphosphonic acid and aminotri(methylene) phosphonic acid; Phase transfer agent: 1-30 parts by weight; the phase transfer agent is polyethylene glycol; Solvent: 5-50 parts by weight; the solvent is water; The crude oil metal removal agent is used to remove trivalent iron ions and calcium ions in crude oil; The removal rate of the crude oil metal removal agent for trivalent iron ions in the crude oil is greater than or equal to 85%, and the removal rate for calcium ions in the crude oil is greater than or equal to 80%.

2. A process for the preparation of the crude oil demetallizing agent of claim 1, characterized in that, The phosphorous acid compound, the reducing agent, the chelating agent, the phase transfer agent and the solvent are uniformly mixed.

3. A method for demetallizing crude oil, characterized by, The method is to use the crude oil metal removal agent of claim 1 to remove metals in crude oil.

4. The method of claim 3 wherein the crude oil is a crude oil from the North Sea. The crude oil metal removal method is specifically as follows: taking the total weight of crude oil as the basis, the crude oil metal removal agent is added into the crude oil at 200 mg / kg, or 800 mg / kg, or 2000 mg / kg of the total weight of the crude oil, and washing water and demulsifier are added into the system to remove metals in the crude oil.

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