Iron-based catalyst for in-situ exploitation of oil shale as well as preparation method and application of iron-based catalyst

Abstract

The invention provides an iron-based catalyst for in-situ exploitation of oil shale as well as a preparation method and application of the iron-based catalyst. The iron-based catalyst for in-situ exploitation of the oil shale comprises the following raw materials: a first active component metal element, a second active component metal element and a silicon source, the metal elements of the first active component comprise iron and auxiliary metal elements in a molar ratio of 1: (0-10), and the metal elements of the second active component comprise one or a combination of more than two of molybdenum, nickel, cobalt and tungsten; the molar ratio of the first active component metal element to the second active component metal element is (1-20): 1; the iron-based catalyst for in-situ exploitation of oil shale is prepared by emulsifying raw materials containing a first active component metal element, a second active component metal element and a silicon source. The iron-based catalyst for in-situ exploitation of the oil shale is stable in structure and can be applied to in-situ exploitation of the oil shale under wide temperature and pressure conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of in-situ thermal exploitation of oil shale, and particularly relates to an iron-based catalyst for in-situ exploitation of oil shale, a preparation method thereof and an application thereof. Background Art

[0002] Oil shale is an unconventional energy source with rich reserves, from which shale oil and related petrochemical products can be extracted. The main organic matter (kerogen) in oil shale can be converted into natural petroleum-like organic matter and gas through pyrolysis or dry distillation, with huge energy storage. Therefore, the development and utilization of oil shale and the development of related science and technology have important significance and academic value.

[0003] In-situ exploitation technology is one of the main ways for the development and utilization of oil shale. Heat is injected into the oil shale to pyrolyze the shale oil into pyrolysis oil and gas, which are then discharged to the ground. The heat sources usually include three methods: heat conduction, convective heating, and radiative heating. However, all these three heating methods have the disadvantages of high energy consumption and a large amount of heat loss. At the same time, the current exploitation technology is still in the small-scale test stage, the technology and process are not yet mature, basic research needs to be strengthened urgently, and the research on the exploitation mechanism needs to be further deepened and improved. Therefore, it is of great significance to study how to improve the oil shale pyrolysis technology efficiently and scientifically.

[0004] Currently, the catalysts used in oil shale pyrolysis include four categories: clay minerals, natural ores (montmorillonite, gypsum, pyrite, etc.) (Mutual Influences between Organic Matter and Minerals during OilShale Pyrolysis, Energy Fuels, 2019, 33(3), 1850 - 1858.), inorganic compounds (metal oxides, metal sulfides, metal salts, etc.) (Behavior, kinetic and product characteristics of thepyrolysis of oil shale catalyzed by cobalt-montmorillonite catalyst, Fuel, 2020, 269:117468.), molecular sieves, and metal-supported catalysts (Progress in Catalytic Pyrolysis ofOil Shale, Scanning, 2021, 6759176.). However, the conversion rate of shale oil in these four catalytic systems is lower than 60%, and the optimal pyrolysis temperature for oil shale (especially medium-low maturity oil shale) is still as high as 450 - 600°C. Many factors such as high catalyst cost and non-reusability seriously limit the development of efficient oil shale pyrolysis technology.

[0005] Therefore, it is urgent to select a suitable liquid catalyst to reduce the activation energy required for the pyrolysis hydrocarbon generation reaction, thereby changing the reaction path and accelerating the reaction rate, so as to reduce the temperature required for in-situ oil and gas conversion of oil shale and improve the quality of oil and gas products.

[0006] CN103878031B discloses a catalyst for oil shale pyrolysis, which is made of the following raw materials by mass percentage: molecular sieve 2%-8%, activated clay 1%-5%, organic cobalt salt 10%-60%, metal sulfide 5%-20%, glycerate 8%-30%, paraffin 15%-35%; the organic cobalt salt is one or more of cobalt acetate, cobalt oxalate, cobalt naphthenate and cobalt neodecanoate; the metal sulfide is molybdenum sulfide and / or nickel sulfide. In addition, the preparation method and usage method of the catalyst are also disclosed. This catalyst can improve the pyrolysis efficiency of oil shale, improve the distribution of oil shale pyrolysis products, produce more light products, and gasoline and diesel components can be separated by rectification. It combines catalytic pyrolysis with microwave heating, can improve the energy utilization efficiency, improve the composition and process properties of liquid fuels, and reduce the subsequent processing difficulty. However, there is no report on the in-situ use of this catalyst for oil shale pyrolysis.

[0007] CN103464179B relates to a catalyst for extracting shale oil from oil shale and its usage method. Before the dry distillation and cracking of oil shale, a catalyst aqueous solution is prepared by mixing divalent cobalt and manganese salts, water and a surfactant in a certain proportion. The catalyst solution is sprayed on the surface of the crushed oil shale, or the oil shale is soaked in the catalyst solution containing a surfactant. After the catalyst solution penetrates into the interior of the oil shale, the oil shale is dried naturally or forcibly, and shale oil is produced according to the existing dry distillation process of crude oil shale. Without changing the existing dry distillation process and equipment, the catalyst is dispersed into the oil shale, reducing the oil shale dry distillation oil output temperature, increasing the oil output rate, increasing the content of saturated hydrocarbons, reducing the content of unsaturated hydrocarbons, and increasing the oil output rate of shale oil; achieving energy conservation and consumption reduction, simple method, and reducing the production cost of shale oil; this technology aims at the mined shale oil and has the effects of reducing the oil shale dry distillation oil output temperature, increasing the oil output rate, increasing the content of saturated hydrocarbons, reducing the content of unsaturated hydrocarbons, and increasing the oil output rate of shale oil. However, it does not involve the catalytic conversion of in-situ shale oil.

[0008] CN108435154A relates to a catalyst for in-situ mining of oil shale and a method of using the catalyst, the catalyst includes magnesium sulfate and water, and the mass ratio of magnesium sulfate to water is 1: (100-1000). The method of using the catalyst is: before the in-situ conversion and mining of oil shale, the oil shale ore layer is cracked and transformed, and then the catalyst solution is injected into the transformed oil shale ore layer, heated to 340-380°C, kept at a constant temperature for 4-8 days, and the oil production channel is opened to allow the generated oil and gas to be exported through the cracks to achieve in-situ mining of oil shale. The catalyst can reduce the oil output temperature of in-situ mining of oil shale, increase the oil and gas output rate, achieve energy saving and consumption reduction, and reduce the production cost of in-situ conversion and mining of oil shale. However, the catalyst for in-situ mining of oil shale is used at a temperature of 340-380°C in the oil shale ore layer, and the constant temperature time is 4-8 days, and there is no report of its use that can be sustained for a long period of time.

[0009] CN114477317B discloses a needle-shaped nano iron-based double metal hydroxide, the metal cations in the layer are Fe 3+ And from Ni 2+ , Mn 2+ With Co 2+ A divalent metal cation is selected from the group consisting of OH - , CO 3 2- and OCN - Composition. Also disclosed are the application of the needle-shaped nano iron-based double metal hydroxide in the process of catalyzing the pyrolysis of oil shale and the catalytic pyrolysis method of oil shale using the needle-shaped nano iron-based double metal hydroxide as a catalyst. The needle-shaped nano iron-based double metal hydroxide has the characteristics of rich active sites, high temperature resistance and stable structure. When the needle-shaped nano iron-based double metal hydroxide is used to catalyze the pyrolysis of oil shale, the pyrolysis temperature can be reduced, the controllable distribution of the pyrolysis products of the oil shale can be achieved, and the pyrolysis products of the oil shale can be converted into medium- and low-carbon hydrocarbon organic matter. However, when the catalyst is used, the particle size of the oil shale needs to be ≤1nm, and there is no report involving in-situ use.

[0010] CN113464103A provides an in-situ cracking and upgrading method for preparing nano-catalysts underground. While heating the formation with a gas burner, a nano-catalyst precursor is fed into the gas burner. Under the high-temperature conditions generated by the gas burner, using the principle of generating nano-scale crystals by the gas-phase method, the nano-catalyst precursor reacts to generate a nano-scale catalyst that can promote the conversion of organic matter in shale and medium-low maturity shale into light oil. The generated nano-scale catalyst is carried by the tail gas generated by the gas burner and transported to the oil shale formation together with the tail gas to catalyze the conversion of organic matter. This preparation method belongs to a heating method that can save energy, improve the energy utilization rate of medium-low maturity shale oil and oil shale, and reduce costs. The catalyst prepared by the gas-phase method has small particle size and good in-situ synthesis and carrying properties, avoiding the use of water when carried by traditional fracturing fluids. However, this technology mainly involves the injection method of nano-catalysts and does not involve the preparation content of specific catalysts. Summary of the Invention

[0011] In order to solve the above problems, the purpose of the present invention is to provide an iron-based catalyst for in-situ exploitation of oil shale, its preparation method and application. The iron-based catalyst for in-situ exploitation of oil shale has a stable structure and can be applied to the in-situ exploitation of oil shale under relatively wide temperature and pressure conditions.

[0012] To achieve the above purpose, the present invention provides an iron-based catalyst for in-situ exploitation of oil shale, the raw material composition of which includes a first active component metal element, a second active component metal element, and a silicon source; the first active component metal element includes iron and a promoter metal element with a molar ratio of 1:0-10, and the second active component metal element includes one or more combinations of molybdenum, nickel, cobalt, and tungsten; the molar ratio of the first active component metal element to the second active component metal element is 1-20:1; the iron-based catalyst for in-situ exploitation of oil shale is obtained by emulsifying raw materials including a first active component metal element, a second active component metal element, and a silicon source.

[0013] According to a specific embodiment of the present invention, preferably, the composition of the iron-based catalyst for in-situ exploitation of oil shale further includes an aluminum source.

[0014] According to a specific embodiment of the present invention, preferably, the sum of the oxides of the aluminum source and the silicon source, Al 2 O 3 and SiO 2 accounts for 0.01-10% of the weight of the iron-based catalyst for in-situ exploitation of oil shale.

[0015] According to a specific embodiment of the present invention, preferably, calculated based on the weight of the iron-based catalyst for in-situ exploitation of oil shale being 100%, the mass fraction of the oxides of all metal elements is 0.1-20%.

[0016] According to a specific embodiment of the present invention, preferably, the aluminum source includes one or more combinations of aluminum isopropoxide, sodium metaaluminate, pseudo-boehmite, α-Al 2 O 3 , β-Al 2 O 3 , γ-Al 2 O 3 and the like.

[0017] According to a specific embodiment of the present invention, preferably, the silicon source includes one or more combinations of tetraethyl orthosilicate, silica sol and sodium silicate.

[0018] According to a specific embodiment of the present invention, preferably, the molar ratio of Si of tetraethyl orthosilicate to other silicon sources in the silicon source is 1:0-1.

[0019] According to a specific embodiment of the present invention, preferably, the molar ratio of Al in the aluminum source to Si in the silicon source is 0-0.5:1.

[0020] According to a specific embodiment of the present invention, preferably, the promoter metal element includes zinc and / or magnesium.

[0021] The present invention also provides a preparation method of an iron-based catalyst for in-situ exploitation of oil shale, which includes the following steps:

[0022] (1) Preparation of a silicon-aluminum mixture:

[0023] After mixing the surfactant, the alkali solution and the solvent, stir at a rate of 300-600 r / min, add the silicon source and stir for 2-10 h, then add the aluminum source and stir for 0.5-1 h to obtain a silicon-aluminum mixture;

[0024] (2) Preparation of an aqueous metal mixture solution:

[0025] Mix the compound of the first active component metal element with water to obtain a first aqueous metal mixture solution;

[0026] Mix the compound of the second active component metal element with water to obtain a second aqueous metal mixture solution;

[0027] (3) Preparation of an oil solution of the metal mixture:

[0028] Mix the compound of the first active component metal element with an organic solvent to obtain a first oil solution of the metal mixture;

[0029] Mix the compound of the second active component metal element with an organic solvent to obtain a second oil solution of the metal mixture;

[0030] (4) Preparation of iron-based catalyst for in-situ exploitation of oil shale:

[0031] Mix the above-mentioned silicon-aluminum mixture, aqueous solution of metal mixture, and oil solution of metal mixture to form an emulsion, thereby obtaining the iron-based catalyst for in-situ exploitation of oil shale. Among them, during mixing, the aqueous solution of metal mixture contains at least a first aqueous solution of metal mixture, and the oil solution of metal mixture contains at least a second oil solution of metal mixture; or, the aqueous solution of metal mixture contains at least a second aqueous solution of metal mixture, and the oil solution of metal mixture contains at least a first oil solution of metal mixture.

[0032] According to a specific embodiment of the present invention, preferably, in step (1), the alkali solution includes an aqueous solution of one or more combinations of sodium hydroxide, potassium hydroxide, and ammonia water.

[0033] According to a specific embodiment of the present invention, preferably, in step (1), the concentration of the alkali solution is 0.01 - 2 mol / L.

[0034] According to a specific embodiment of the present invention, preferably, in step (1), the solvent is water and / or ethanol.

[0035] According to a specific embodiment of the present invention, preferably, in step (1), the surfactant includes one or more combinations of cetyltrimethylammonium bromide, tetrapropylammonium bromide, hexamethylammonium bromide, hexamethyleneimine, triethylamine, di-n-propylamine, and N,N,N-trimethyl-1,1-adamantylammonium hydroxide.

[0036] According to a specific embodiment of the present invention, preferably, in step (2), the compound of the first active component metal element iron includes one or more combinations of iron nitrate, iron sulfate, ferrous sulfate, iron chloride, and iron phosphate.

[0037] According to a specific embodiment of the present invention, preferably, in step (2), the compound of the promoter metal element in the first active component metal element includes one or more combinations of zinc nitrate, zinc sulfate, zinc chloride, zinc phosphate, magnesium nitrate, magnesium sulfate, magnesium chloride, and magnesium phosphate.

[0038] According to a specific embodiment of the present invention, preferably, in step (2), the compound of the second active component metal element includes one or more combinations of cobalt nitrate, ammonium molybdate, nickel nitrate, and ammonium metatungstate.

[0039] According to a specific embodiment of the present invention, preferably, in step (3), the compound of the first active component metal element iron includes iron nitrate, iron chloride, iron phosphate, and iron naphthenate.

[0040] According to a specific embodiment of the present invention, preferably, in step (3), the compound of the promoter metal element in the first active component metal element includes zinc acetate dihydrate and / or magnesium nitrate.

[0041] According to a specific embodiment of the present invention, preferably, in step (3), the type of the compound of the second active component metal element includes one or a combination of two or more of naphthenates, acetylacetone compounds, carbonyl compounds, aromatic acid salts, alkyl-substituted phosphates, and organic amine salts.

[0042] According to a specific embodiment of the present invention, preferably, in step (3), the organic solvent includes one or a combination of two or more of hydrotreated diesel, catalytic diesel, waste grease, petroleum ether, and toluene.

[0043] According to a specific embodiment of the present invention, preferably, in step (4), during mixing, the mixing mass ratio of the silica-alumina mixture, the aqueous metal mixture solution, and the oil solution of the metal mixture is 1:10 - 1000:1 - 500.

[0044] According to a specific embodiment of the present invention, the above preparation method includes the following specific steps:

[0045] (1) Preparation of the silica-alumina mixture:

[0046] After mixing a certain amount of CTAB (cetyltrimethylammonium bromide), lye, and ethanol evenly, stir at a rate of 300 - 600 r / min, add the silicon source at one time and stir for 2 - 10 h, then add the aluminum source and stir for 0.5 - 1 h to obtain the silica-alumina mixture;

[0047] (2) Preparation of the aqueous metal mixture solution:

[0048] Weigh the iron salt and the promoter metal salt and mix them evenly with a certain amount of deionized water to obtain the first aqueous metal mixture solution;

[0049] Weigh the salt of at least one of Mo, Ni, Co, and W and mix it evenly with a certain amount of deionized water to obtain the second aqueous metal mixture solution;

[0050] (3) Preparation of the oil solution of the metal mixture:

[0051] Mix the compound of the first active component metal element in the organic solvent to obtain the first oil solution of the metal mixture;

[0052] Mix the compound of the second active component metal element (such as organic acid salt or metal organic compound) in the organic solvent to obtain the second oil solution of the metal mixture;

[0053] (4) Finally, the silicon-aluminum mixture, the aqueous solution of the metal mixture, and the oil solution of the metal mixture are mixed in proportion and stirred thoroughly until evenly mixed to form an emulsion, and then the iron-based catalyst for in-situ oil shale mining is obtained.

[0054] The present invention also provides a method for in-situ oil shale mining, which uses the above-mentioned iron-based catalyst for in-situ oil shale mining.

[0055] According to a specific embodiment of the present invention, preferably, the mining temperature of the in-situ oil shale mining method is 250-650 °C, and the pressure is 3-50 MPa.

[0056] According to a specific embodiment of the present invention, preferably, the iron-based catalyst for in-situ oil shale mining is injected into the formation through an injection well and / or a heating well. Among them, the above-mentioned heating well and injection well need to contain a channel, which can be used to inject the iron-based catalyst for in-situ oil shale mining. During the injection and use of this catalyst, with the increase of temperature, micro-nano particles with high reactivity can be obtained in-situ.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] 1. The iron-based catalyst for in-situ oil shale mining of the present invention has the characteristics of rich active sites, strong adaptability, and stable structure;

[0059] 2. The iron-based catalyst for in-situ oil shale mining of the present invention exists in the form of an emulsion, which is convenient to be injected into the injection well and can be injected into the formation through the injection well and / or the heating well, promoting the in-situ conversion of shale oil and being used under relatively wide temperature and pressure conditions. It is a method for preparing and using a catalyst suitable for medium-mature shale oil and in-situ oil shale mining. Specific Embodiments

[0060] In order to have a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below, but it should not be construed as a limitation on the implementable scope of the present invention.

[0061] The experimental methods used in the following examples are all conventional methods unless otherwise specified.

[0062] The materials, reagents, etc. used in the following examples can be obtained from commercial channels unless otherwise specified.

[0063] Example 1

[0064] This example provides an iron-based catalyst for in-situ oil shale mining, which is prepared by the following steps:

[0065] (1) Weigh 1.2 g of CTAB (cetyltrimethylammonium bromide), 40 g of 0.45 mol / L sodium hydroxide, and 24 g of ethanol. After mixing them evenly, stir at a rate of 300 r / min, and add 8.4 g of tetraethyl orthosilicate all at once and stir for 4 h to obtain the silica-alumina mixture A;

[0066] (2) Weigh 8.08 g of the first active component metal of iron nitrate and mix it evenly with 150.0 g of deionized water to obtain the aqueous metal mixture solution A;

[0067] (3) Weigh 11.23 g of the second active component metal of molybdenum naphthenate and mix it with 100.0 g of petroleum ether and 50.0 g of catalytic diesel to obtain the oil solution of the metal mixture A;

[0068] (4) Weigh 0.1 g of the silica-alumina mixture A, 100.0 g of the aqueous metal mixture solution A, and 12.0 g of the oil solution of the metal mixture A. After mixing them, ultrasonicate for 10 min at 60 °C to obtain a uniform water-in-oil emulsion mixture, which is the iron-based catalyst A for in-situ oil shale mining.

[0069] Example 2

[0070] This example provides an iron-based catalyst for in-situ oil shale mining, which is prepared by the following steps:

[0071] (1) Weigh 0.6 g of CTAB (cetyltrimethylammonium bromide), 90 g of 1.0 mol / L potassium hydroxide, and 30 g of ethanol. After mixing them evenly, stir at a rate of 600 r / min, add 17.5 g of tetraethyl orthosilicate and 8.4 g of silica sol (30%) all at once and stir for 8 h, then add 20.5 g of aluminum isopropoxide and stir for another 5 h to obtain the silica-alumina mixture B;

[0072] (2) Weigh 2.0 g of ferric sulfate and 12.04 g of magnesium sulfate as the first active component metal and mix it evenly with 45.0 g of deionized water to obtain the aqueous metal mixture solution B;

[0073] (3) Weigh 40.1 g of the second active component metal of nickel naphthenate and mix it with 30.0 g of toluene and 30.0 g of catalytic diesel to obtain the oil solution of the metal mixture B;

[0074] (4) Weigh 0.2 g of the silica-alumina mixture B, 20.0 g of the aqueous metal mixture solution B, and 4.0 g of the oil solution of the metal mixture B. After mixing them, ultrasonicate for 10 min at 50 °C to obtain a uniform water-in-oil emulsion mixture, which is the iron-based catalyst B for in-situ oil shale mining.

[0075] Example 3

[0076] This embodiment provides an iron-based catalyst for in-situ exploitation of oil shale, which is prepared by the following steps:

[0077] (1) Weigh 1.0 g of CTAB (cetyltrimethylammonium bromide), 10 g of 2.0 mol / L ammonia water and 4 g of ethanol, mix them evenly, stir at a rate of 400 r / min, add 41.0 g of tetraethyl orthosilicate and 3.9 g of silica sol (30%) at one time and stir for 2 h, then add 21.9 g of α-Al 2 O 3 Stir for another 0.5 h to obtain the silicon-aluminum mixture C;

[0078] (2) Weigh 3.74 g of ferric phosphate and 23.17 g of zinc phosphate as the first active component metals, mix them evenly with 104.0 g of deionized water to obtain the metal mixture aqueous solution C;

[0079] (3) Weigh 4.01 g of cobalt naphthenate as the second active component metal, mix it with 20.0 g of toluene and 80.0 g of hydrotreated diesel to obtain the metal mixture oil solution C;

[0080] (4) Weigh 0.2 g of the silicon-aluminum mixture C, 100.0 g of the metal mixture aqueous solution C, and 20.0 g of the metal mixture oil solution C, mix them, and ultrasonically treat them for 10 min at 50 °C to obtain a uniform water-in-oil emulsion mixture, that is, the iron-based catalyst C for in-situ exploitation of oil shale.

[0081] Example 4

[0082] This embodiment provides an iron-based catalyst for in-situ exploitation of oil shale, which is prepared by the following steps:

[0083] (1) Weigh 3.0 g of hexamethylammonium bromide, 20 g of 0.05 mol / L sodium hydroxide and 40 g of ethanol, mix them evenly, stir at a rate of 600 r / min, add 40.8 g of tetraethyl orthosilicate at one time and stir for 5 h to obtain the silicon-aluminum mixture D;

[0084] (2) Weigh 2.84 g of ammonium metatungstate as the second active component metal, mix it evenly with 100.0 g of deionized water to obtain the metal mixture aqueous solution D;

[0085] (3) Weigh 11.392 g of iron naphthenate as the first active component metal, mix it with 40.0 g of toluene and 40.0 g of hydrotreated diesel to obtain the metal mixture oil solution D;

[0086] (4) Weigh 0.2 g of silicon-aluminum mixture D, 20.0 g of aqueous metal mixture D, and 50.0 g of oil-based metal mixture D, mix them, and ultrasonically treat for 10 min at 50 °C to obtain a homogeneous water-in-oil emulsion mixture, namely the iron-based catalyst D for in-situ oil shale exploitation.

[0087] Example 5

[0088] This example provides an iron-based catalyst for in-situ oil shale exploitation, which is prepared by the following steps:

[0089] (1) Weigh 0.8 g of triethylamine, 10 g of 0.5 mol / L ammonia water, and 5 g of deionized water, mix them evenly, stir at a rate of 500 r / min, add 5.8 g of tetraethyl orthosilicate and 2.87 g of silica sol (30%) at one time and stir for 10 h, then add 1.45 g of pseudoboehmite and stir for 1 h to obtain silicon-aluminum mixture E;

[0090] (2) Weigh 1.163 g of the second active component metal of nickel nitrate and 80.0 g of deionized water, mix them evenly to obtain aqueous metal mixture E;

[0091] (3) Weigh 1.01 g of the first active component metal of iron nitrate and 1.483 g of magnesium nitrate, mix them with 20.0 g of hydrogenated diesel and 50.0 g of catalytic diesel to obtain oil-based metal mixture E;

[0092] (4) Weigh 0.5 g of silicon-aluminum mixture E, 80.0 g of aqueous metal mixture E, and 5.0 g of oil-based metal mixture E, mix them, and ultrasonically treat for 10 min at 50 °C to obtain a homogeneous water-in-oil emulsion mixture, namely the iron-based catalyst E for in-situ oil shale exploitation.

[0093] Example 6

[0094] This example provides an iron-based catalyst for in-situ oil shale exploitation, which is prepared by the following steps:

[0095] (1) Weigh 0.4 g of CTAB (cetyltrimethylammonium bromide), 6 g of 0.5 mol / L potassium hydroxide, and 4 g of ethanol, mix them evenly, stir at a rate of 600 r / min, add 4.5 g of tetraethyl orthosilicate at one time and stir for 4 h, then add 0.65 g of γ-Al 2 O 3 and stir for another 0.5 h to obtain silicon-aluminum mixture F;

[0096] (2) Weigh 0.98 g of ammonium molybdate and 1.46 g of the second active component metal of cobalt nitrate, mix them with 20.0 g of deionized water evenly to obtain aqueous metal mixture F;

[0097] (3) Weigh 1.87 g of iron phosphate and 4.39 g of zinc acetate dihydrate as the first active component metals, mix them with 10.0 g of petroleum ether and 1.0 g of catalytic diesel to obtain the metal mixture oil solution F;

[0098] (4) Weigh 1.0 g of the silicon-aluminum mixture F, 10.0 g of the metal mixture aqueous solution F, and 2.0 g of the metal mixture oil solution F, mix them, and ultrasonically treat for 10 min at 50 °C to obtain a homogeneous water-in-oil emulsion mixture, which is the iron-based catalyst F for in-situ oil shale exploitation.

[0099] Example 7

[0100] This example provides an iron-based catalyst for in-situ oil shale exploitation, which is prepared by the following steps:

[0101] (1) Weigh 1.6 g of tetrapropylammonium bromide, 2.0 g of 1 mol / L sodium hydroxide, and 5 g of ethanol, mix them evenly, stir at a rate of 600 r / min, add 10.0 g of tetraethyl orthosilicate and 10.0 g of water glass at one time and stir for 2 h, then add 5 g of sodium aluminate and stir for another 0.5 h to obtain the silicon-aluminum mixture F;

[0102] (2) Weigh 2.78 g of ferrous sulfate and 16.1 g of zinc sulfate as the first active component metals, mix them evenly with 50.0 g of deionized water to obtain the metal mixture aqueous solution G;

[0103] (3) Weigh 1.28 g of nickel acetylacetonate and 0.182 g of tungsten hexacarbonyl as the second active component metals, mix them with 10.0 g of toluene and 40.0 g of catalytic diesel to obtain the metal mixture oil solution G;

[0104] (4) Weigh 2.0 g of the silicon-aluminum mixture G, 20.0 g of the metal mixture aqueous solution G, and 2.0 g of the metal mixture oil solution G, mix them, and ultrasonically treat for 10 min at 50 °C to obtain a homogeneous water-in-oil emulsion mixture, which is the iron-based catalyst G for in-situ oil shale exploitation.

[0105] Comparative Example 1

[0106] This comparative example provides a catalyst, which is prepared by the following steps:

[0107] Fully mix 0.41 g of iron nitrate, 5.62 g of molybdenum naphthenate, 4.17 g of tetraethyl orthosilicate, 0.5 g of cetyltrimethylammonium bromide, and 5.0 g of ethanol to obtain the comparative catalyst 1.

[0108] Comparative Example 2

[0109] This comparative example provides a catalyst, which is prepared by the following steps:

[0110] 2.84 g of ammonium metatungstate, 28.48 g of iron naphthenate, 2.57 g of silica sol, 1.54 g of aluminum isopropoxide, 1.0 g of tetrapropylammonium bromide, 5.0 g of water, and 2.0 g of ethanol were thoroughly mixed to obtain Comparative Catalyst 2.

[0111] Test Example

[0112] The iron-based catalysts for in-situ oil shale mining in Examples 1-7 were injected into the oil shale reservoir through injection wells and heating wells. The temperature of the oil shale was raised to 300-450 °C using the heating wells and kept constant for 5-10 days to generate oil and gas.

[0113] The oil production channel was opened, and the generated oil and gas were exported through the fractures to achieve in-situ mining of oil shale.

[0114] The method for in-situ conversion of oil shale using the catalyst of the present invention can significantly improve the in-situ oil and gas production rate compared with the existing in-situ dry distillation mining. Under the same conditions, the oil and gas production rate of in-situ mining of oil shale using the catalyst of the present invention can effectively reduce the mining temperature compared with the existing in-situ dry distillation mining.

[0115] A test range of 5 m × 5 m was selected in an oil shale reservoir somewhere. Injection wells, heating wells, and production wells were arranged. The well depth was 80 m, the buried depth of the oil shale roof was 60 m, the thickness of the oil shale layer was 15 m, and the oil content rate of the oil shale reservoir measured by the aluminum retort method was 15.3%. The catalyst used was 10 g. The specific conditions and results are shown in Table 1 below:

[0116] Table 1 Test Conditions and Oil Production Rate

[0117]

[0118]

[0119] Result Analysis: Using the catalyst of the present invention, the lowest oil production rate of in-situ catalytic mining at 300 °C was 6.13%, and the highest oil production rate of in-situ catalytic mining at 450 °C was 13.98%. The in-situ oil production rate can be significantly improved compared with the existing in-situ dry distillation mining. Generally, it is considered that the final oil production rate of oil shale in the in-situ dry distillation mining test area at 500 °C (40%-60% of the oil content rate measured by the aluminum retort method) is 6.12-9.18%. It can be seen that after using the catalyst of the present invention, the in-situ oil production rate at 300 °C is close to the oil production rate of dry distillation conversion mining at 500 °C, and the effect is remarkable.

[0120] It should be noted that the above-described embodiments are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described by referring to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words rather than limiting words. Modifications can be made to the invention within the scope of the claims of the present invention as stipulated, and the present invention can be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. An iron-based catalyst for in-situ exploitation of oil shale, the raw material composition of which comprises a first active component metal element, a second active component metal element, and a silicon source; the first active component metal element comprises iron and a promoter metal element with a molar ratio of 1:0-10, and the second active component metal element comprises one or more combinations of molybdenum, nickel, cobalt, and tungsten; the molar ratio of the first active component metal element to the second active component metal element is 1-20:1; The iron-based catalyst for in-situ exploitation of oil shale is obtained by emulsifying raw materials comprising a first active component metal element, a second active component metal element, and a silicon source; Preferably, the composition of the iron-based catalyst for in-situ exploitation of oil shale further comprises an aluminum source.

2. The iron-based catalyst for in-situ exploitation of oil shale according to claim 1, wherein, The sum of the weights of the oxides of the aluminum source and the silicon source, i.e., Al 2 O 3 and SiO 2 accounts for 0.01-10% of the weight of the iron-based catalyst for in-situ exploitation of oil shale; Preferably, calculated based on the weight of the iron-based catalyst for in-situ exploitation of oil shale being 100%, the mass fraction of the oxides of all metal elements is 0.1-20%.

3. The iron-based catalyst for in-situ exploitation of oil shale according to claim 1 or 2, wherein, The aluminum source includes one or more combinations of aluminum isopropoxide, sodium metaaluminate, pseudo-boehmite, α-Al 2 O 3 , β-Al 2 O 3 , γ-Al 2 O 3 ; Preferably, the silicon source comprises one or more combinations of tetraethyl orthosilicate, silica sol, and water glass.

4. The iron-based catalyst for in-situ exploitation of oil shale according to claim 3, wherein, The molar ratio of Si of tetraethyl orthosilicate to other silicon sources in the silicon source is 1:0-1; Preferably, the molar ratio of Al in the aluminum source to Si in the silicon source is 0-0.5:

1.

5. The iron-based catalyst for in-situ exploitation of oil shale according to claim 1, wherein, The promoter metal element comprises zinc and / or magnesium.

6. The preparation method of the iron-based catalyst for in-situ exploitation of oil shale according to any one of claims 1-5, which comprises the following steps: (1) Preparation of a silicon-aluminum mixture: After mixing a surfactant, an alkali solution, and a solvent, stir at a rate of 300-600 r / min, add a silicon source and stir for 2-10 h, add an aluminum source and stir for another 0.5-1 h to obtain a silicon-aluminum mixture; (2) Preparation of an aqueous metal mixture solution: Mix the compounds of the first active component metal element in water to obtain a first aqueous metal mixture solution; Mix the compounds of the second active component metal element in water to obtain a second aqueous metal mixture solution; (3) Preparation of an oil solution of the metal mixture: Mix the compounds of the first active component metal element in an organic solvent to obtain a first oil solution of the metal mixture; Mix the compounds of the second active component metal element in an organic solvent to obtain a second oil solution of the metal mixture; (4) Preparation of the iron-based catalyst for in-situ exploitation of oil shale: Mix the above-mentioned silicon-aluminum mixture, aqueous solution of metal mixture, and oil solution of metal mixture for emulsification to obtain the iron-based catalyst for in-situ oil shale mining; wherein, during mixing, the aqueous solution of metal mixture contains at least a first aqueous solution of metal mixture, and the oil solution of metal mixture contains at least a second oil solution of metal mixture; or, the aqueous solution of metal mixture contains at least a second aqueous solution of metal mixture, and the oil solution of metal mixture contains at least a first oil solution of metal mixture.

7. The preparation method according to claim 6, wherein, in step (1), the alkali solution includes an aqueous solution of one or a combination of two or more of sodium hydroxide, potassium hydroxide, and ammonia water; Preferably, the concentration of the alkali solution is 0.01 - 2 mol / L; Preferably, the solvent is water and / or ethanol; Preferably, the surfactant includes one or a combination of two or more of cetyltrimethylammonium bromide, tetrapropylammonium bromide, hexamethonium bromide, hexamethyleneimine, triethylamine, di-n-propylamine, and N,N,N-trimethyl-1,1-adamantylammonium hydroxide.

8. The preparation method according to claim 6, wherein, in step (2), the compound of the first active component metal element iron includes one or a combination of two or more of ferric nitrate, ferric sulfate, ferrous sulfate, ferric chloride, and ferric phosphate; Preferably, in step (2), the compound of the promoter metal element in the first active component metal element includes one or a combination of two or more of zinc nitrate, zinc sulfate, zinc chloride, zinc phosphate, magnesium nitrate, magnesium sulfate, magnesium chloride, and magnesium phosphate; Preferably, in step (2), the compound of the second active component metal element includes one or a combination of two or more of cobalt nitrate, ammonium molybdate, nickel nitrate, and ammonium metatungstate.

9. The preparation method according to claim 6, wherein, in step (3), the compound of the first active component metal element iron includes ferric nitrate, ferric chloride, ferric phosphate, and iron naphthenate; Preferably, in step (3), the compound of the promoter metal element in the first active component metal element includes zinc acetate dihydrate and / or magnesium nitrate; Preferably, in step (3), the type of the compound of the second active component metal element includes one or a combination of two or more of naphthenates, acetylacetone compounds, carbonyl compounds, aromatic acid salts, alkyl-substituted phosphates, and organic amine salts; Preferably, in step (3), the organic solvent includes one or a combination of two or more of hydrotreated diesel, catalytic diesel, waste grease, petroleum ether, and toluene.

10. The preparation method according to claim 6, wherein, in step (4), during mixing, the mixing mass ratio of the silicon-aluminum mixture, aqueous solution of metal mixture, and oil solution of metal mixture is 1:10 - 1000:1 - 500.

11. An in-situ oil shale mining method, which is carried out by using the iron-based catalyst for in-situ oil shale mining according to any one of claims 1 - 5; Preferably, the mining temperature of the in-situ oil shale mining method is 250 - 650 °C, and the pressure is 3 - 50 MPa; Preferably, the iron-based catalyst for in-situ oil shale exploitation is injected into the formation through injection wells and / or heating wells.

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