Preparation method and application of alkyl dithiocarbamic acid metal catalyst

Abstract

The invention discloses an alkyl dithiocarbamic acid metal catalyst preparation method, which comprises: uniformly mixing secondary amine, an alkali liquid and a first organic solvent, adding carbon disulfide, carrying out a reaction to obtain alkyl dithiocarbamic acid or a salt thereof, adding a metal source, carrying out a reaction, and after the reaction is completed, carrying out separation and drying to obtain the alkyl dithiocarbamic acid metal catalyst. Dissolving the obtained catalyst precursor in a second organic solvent, and then uniformly mixing with a hydrogen donor to obtain the alkyl dithiocarbamic acid metal catalyst, the whole preparation process is carried out at normal temperature, so that the energy consumption in the synthesis process is greatly reduced, and meanwhile, the safety is improved. After the catalyst prepared by the method is injected underground, thermal decomposition is carried out by utilizing underground high temperature, the generated active component metal sulfide is dispersed in a nanoscale and can enter gaps of an oil shale layer to catalyze in-situ pyrolysis of rock stratum organic matters to generate large gaps, then a molecular sieve catalyst is injected, and the catalyst is suitable for in-situ exploitation of oil shale.

Description

Technical Field

[0001] The invention relates to the technical field of in-situ thermal conversion of oil shale, and in particular to a preparation method and application of an alkyl dithiocarbamate metal catalyst. Background Art

[0002] Oil shale (also known as kerogen shale) is a high-ash sedimentary rock containing combustible organic matter. The main difference between it and coal is that the ash content exceeds 40%, and the main difference between it and carbonaceous shale is that the oil content is greater than 3.5%. Oil shale belongs to unconventional oil and gas resources. It is listed as a very important successor energy in the 21st century due to its rich resources and feasibility of development and utilization. It is a non-renewable fossil energy like oil, natural gas and coal.

[0003] Oil shale is a kind of rock with high oil content, which is often mined in situ. In situ mining means that after the shale is crushed underground, water, catalysts and other substances are injected into it, so that the oil and water inside the rock form an emulsion and discharge it through the wellhead. However, most of the existing oil shale underground injections use molecular sieve catalysts, which have the disadvantage of being large in particle size and difficult to enter the rock layer. If oil-soluble nano-metal disulfide is used, it is easy to be deactivated during the injection process into the well, because it is already lamellar and highly active, resulting in a significant reduction in the mining efficiency of oil shale.

[0004] Effective catalysts can significantly reduce the activation energy required for oil shale cracking, improve in-situ conversion efficiency, and improve the quality of cracked oil products, and are an effective way to increase the recovery rate of oil shale. Although the catalytic effects of authigenic minerals, metal salts, and metal oxides have been systematically studied, there are few reports on their applicability and effectiveness in in-situ conversion processes. In addition, considering the requirement for catalyst portability during the in-situ conversion of oil shale, it is necessary to develop and screen effective nano-catalysts and feasible catalyst injection processes to achieve in-situ efficient catalytic conversion and exploitation of oil shale.

[0005] In view of the above problems, for example, Chinese patent document CN112371137A discloses a method for preparing and applying a self-sulfurizing oil-soluble multi-metal composite hydrocracking catalyst, wherein sodium polyol is added to carbon disulfide for reaction to obtain sodium alkyl dithiocarbonate, and then sodium alkyl dithiocarbonate is added to a mixed solution of group VIII metal iron source, cobalt source and nickel source for reaction to obtain an oil-soluble multi-metal composite catalyst. Adding a dispersant can achieve rapid mutual dissolution and stable dispersion of the multi-metal composite catalyst in inferior heavy oil, and can self-sulfurize and decompose to form nano-scale dispersed active metal composite sulfides, which have excellent hydrogenation activity and coke inhibition performance. The catalyst has the characteristics of simple preparation process, no need for sulfurization, small amount of catalyst addition, and simple application. It is suitable for low-cost slurry bed hydrocracking process of high-metal, high-residue carbon, and high-viscosity inferior heavy oil, and is also suitable for slurry bed hydrogenation pretreatment purification and purification process of waste lubricating oil. However, the synthesis route of the catalyst preparation process is polyol-polyol sodium-alkyl dithiocarbonate sodium-oil-soluble polymetallic catalyst precursor, and the reaction process is complicated and dangerous. In addition, the reaction needs to be heated to above 50°C multiple times, which consumes a lot of energy in actual production.

[0006] Chinese patent document CN103349999A discloses an oil-soluble self-sulfurized molybdenum catalyst, its preparation method, use method and application, and the preparation method comprises the following steps: (1) under nitrogen protection, a molybdenum source, water, sodium sulfide, a solvent, and an inorganic acid are placed in a container in order, mixed and stirred evenly, and cooled at 5-50° C., and reacted for 10-150 min; (2) an alkylamine and carbon disulfide are added, stirred evenly, heated to 60-200° C. and reacted for 3-10 h; (3) after the reaction is completed, the product is fully cooled and filtered, fully washed with methanol, and dried to obtain an oil-soluble self-sulfurized molybdenum catalyst. However, the synthesis process of the oil-soluble catalyst needs to be heated, which consumes a lot of energy in actual production and is more dangerous.

[0007] Chinese patent document CN106391111 discloses an oil-soluble catalyst and a method for preparing the same. Soluble salts of VIB group metals Mo and / or W, soluble salts of at least one of VIII group metals Fe, Co or Ni and water are mixed to obtain a mixed solution; after adjusting the pH of the mixed solution to alkaline, a precipitation reaction is carried out at 40-100°C to obtain an active metal precursor; in an oxygen-free atmosphere, the active metal precursor and an organic precursor compound are reacted to obtain an oil-soluble catalyst. Although this type of oil-soluble catalyst exhibits excellent hydrocracking performance, a sulfiding agent must be added to the precursor to convert it into a catalytically active metal sulfide. Due to the difficulty of sulfidation, the final sulfide particle size is generally larger in this process, which reduces the catalytic hydrogenation activity, resulting in a large amount of addition and increasing the cost of operation.

[0008] Chinese patent document CN103977822B discloses a method for preparing an oil-soluble composite suspended bed hydrocracking catalyst, which comprises the following steps: 1) using compounds of molybdenum, tungsten and cerium as metal sources, reacting with alkali metal sulfide or alkali metal hydrosulfide at a molar ratio of 0.5:1 to 2:1 to obtain a reduced metal element compound; 2) adding the reduced metal element compound and amine substances at a molar ratio of 1:0.6 to 1:2 to a reaction medium, and at the same time, adding a corresponding amount of carbon disulfide dropwise to the reaction medium at a molar ratio of 1:1 to 2:1 to the reduced metal element compound, heating the reaction medium for reaction, the reaction temperature being 30 to 110°C, and the reaction time being 2 to 10 hours; 3) filtering and washing the product obtained in step 2) to obtain an oil-soluble composite suspended bed hydrocracking catalyst; the active metal content in the oil-soluble composite suspended bed hydrocracking catalyst is 10 to 40%. The catalyst has excellent catalytic performance. Currently, no such catalyst has been applied to the coal direct liquefaction suspension bed slurry bed hydrocracking process. The use of the catalyst of the present invention can significantly reduce the coke yield, maintain the long-term operation of the device (if the coke yield is high, it is easy to block the equipment and shorten the operation cycle of the device), and improve the removal rate of heteroatoms such as sulfur and nitrogen. However, the preparation process is relatively complicated and requires a temperature increase operation, which consumes a lot of energy in actual production.

[0009] Chinese patent document CN103878031B discloses a catalyst for pyrolysis of oil shale, which is made of the following raw materials in percentage by mass: 2% to 8% molecular sieve, 1% to 5% activated clay, 10% to 60% organic cobaltate, 5% to 20% metal sulfide, 8% to 30% glycerate, and 15% to 35% paraffin; the organic cobaltate is one or more of cobalt acetate, cobalt oxalate, cobalt naphthenate, and cobalt neodecanoate; the metal sulfide is molybdenum sulfide and / or nickel sulfide. The catalyst can improve the pyrolysis efficiency of oil shale, improve the distribution of pyrolysis products of oil shale, produce more light products, and separate gasoline and diesel components by distillation. The present invention combines catalytic pyrolysis with microwave heating, which can improve energy utilization efficiency, improve the composition and process properties of liquid fuels, and reduce the difficulty of subsequent processing. However, if the supported catalyst is directly injected into the ground for in-situ conversion catalysis, it is not easy to enter the rock layer because of its large particle size, resulting in low catalytic efficiency. Summary of the invention

[0010] In view of this, the present invention provides a method for preparing an alkyl amino disulfide metal catalyst, wherein the entire reaction process is carried out at room temperature, and no heating operation is required, which greatly reduces the energy consumption in the synthesis process and improves safety. Moreover, after the catalyst prepared by the method is injected underground, it is thermally decomposed by utilizing the high temperature underground, and the generated active component metal sulfide is dispersed in nanometer scale and can enter the gaps of the oil shale layer, catalyze the in-situ thermal decomposition of the organic matter in the rock layer to produce large gaps, and then inject the molecular sieve catalyst, which is a catalyst suitable for in-situ mining of oil shale.

[0011] To achieve the above object, the present invention provides a method for preparing an alkyl dithiocarbamate metal catalyst, comprising the following steps:

[0012] (1) after uniformly mixing a secondary amine, an alkali solution and a first organic solvent, adding carbon disulfide to react to obtain an alkyl amino dithiocarboxylic acid or a salt thereof;

[0013] (2) adding a metal source to the alkylamino acid or its salt to react, and after the reaction is completed, separating and drying to obtain a catalyst precursor;

[0014] (3) dissolving the catalyst precursor in a second organic solvent, and then mixing it with a hydrogen donor to obtain the alkyl dithiocarbamate metal catalyst;

[0015] The entire preparation process is carried out at room temperature, the molar ratio of the secondary amine to the carbon disulfide is 1:(1-4); the molar ratio of the metal source, calculated as metal element, to the metal source is 1:(0.3-0.5);

[0016] The metal source is selected from at least one of an iron source, a cobalt source and a nickel source;

[0017] The mass ratio of the catalyst precursor to the hydrogen donor is 1:(1-10).

[0018] Optionally, in the preparation method of the alkylaminothioic acid metal catalyst provided by the present invention, the type of the metal source is not specifically limited and can be selected as one, two or three. When the metal source is two or three, the specific molar ratio of the various metals has no substantial effect on the catalytic performance of the catalyst and can be compounded in any proportion, such as the iron source and the nickel source can be compounded in any molar ratio, the cobalt source and the nickel source can be compounded in any molar ratio, and the iron source and the cobalt source can be compounded in any molar ratio, as long as the molar ratio of the secondary amine to the metal source is within the above-defined range. In terms of metal elements, the molar ratio of the iron source, the cobalt source and the nickel source recommended by the present invention is (0.1~10):(0.1~10):1.

[0019] In the above step (1), the time and method of mixing the secondary amine, the alkali solution and the first organic solvent are not specifically limited, as long as they can be mixed evenly. The mixing method recommended by the present invention is stirring mixing, and the mixing time is 1 to 2 hours. The time recommended by the present invention for adding carbon disulfide to react is 0.5 to 10 hours, preferably 0.5 to 2 hours.

[0020] Optionally, in the method for preparing the alkylaminosulfuric acid metal catalyst provided by the present invention, the molar ratio of the secondary amine to the solute in the alkali solution is 1:(1-2).

[0021] Optionally, in the method for preparing the alkylaminothiocarboxylic acid metal catalyst provided by the present invention, the secondary amine is selected from any one of diethylamine, dipropylamine, di-n-butylamine, dipentylamine and dihexylamine.

[0022] Optionally, in the method for preparing the alkyl amidosulfuric acid metal catalyst provided by the present invention, the hydrogen donor is selected from at least one of tetralin, dihydroanthracene and decalin.

[0023] Optionally, in the method for preparing the alkylamino disulfide metal catalyst provided by the present invention, the first organic solvent is selected from at least one of tetrahydrofuran, toluene, DMF, n-hexane and petroleum ether; the specific amount of the first organic solvent is not limited, as long as the secondary amine and the alkali solution can be mixed and dispersed uniformly;

[0024] The second organic solvent is selected from at least one of hydrogenated diesel, catalytic diesel, waste oil, petroleum ether and toluene. The amount of the second organic solvent is not specifically limited, as long as it can dissolve the catalyst precursor.

[0025] Optionally, in the method for preparing the alkyl amidosulfate metal catalyst provided by the present invention, the alkali solution is selected from at least one of sodium hydroxide solution, potassium hydroxide solution and concentrated ammonia solution.

[0026] Optionally, in the method for preparing the alkylamino disulfide metal catalyst provided by the present invention, the nickel salt is selected from at least one of nickel nitrate, nickel acetate, basic nickel carbonate, nickel chloride and nickel sulfate;

[0027] The cobalt salt is selected from at least one of cobalt nitrate, cobalt acetate, basic cobalt carbonate, cobalt chloride and cobalt sulfate;

[0028] The iron salt is selected from at least one of ferric nitrate, ferric acetate, ferric chloride and ferric sulfate.

[0029] The present invention also provides an application of the alkyl dithiocarbamate metal catalyst prepared by the preparation method of the alkyl dithiocarbamate metal catalyst in in-situ mining of oil shale.

[0030] The present invention also provides a method for mining oil shale, which includes the following steps: injecting a metal alkyl dithiocarbamate catalyst into the ground through an injection well for in-situ mining, and then heating it to 350-600 °C for in-situ conversion for 1-60 days (at this time, the particle size of the active components generated after the pyrolysis of the metal alkyl dithiocarbamate catalyst is less than 20 nm), and the oil and gas generated by pyrolysis are produced through a production well;

[0031] Among them, the metal alkyl dithiocarbamate catalyst is prepared by the above-mentioned preparation method of the metal alkyl dithiocarbamate catalyst.

[0032] Optionally, in the method for mining oil shale provided by the present invention, after the production well produces, it further includes a step of injecting a molecular sieve catalyst into the ground to continue deep pyrolysis.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects:

[0034] Beneficial effect 1: In the preparation method of the metal alkyl dithiocarbamate catalyst provided by the present invention, alkyl dithiocarbamic acid / alkyl dithiocarbamate is first synthesized, and then a metal solution is added to generate an oil-soluble catalyst precursor. All three-step reactions can be carried out at room temperature without heating operation, which greatly reduces the energy consumption in the synthesis process and improves the safety at the same time. Moreover, after the metal alkyl dithiocarbamate catalyst is injected into the ground, it is thermally decomposed using the high temperature in the ground itself to generate a catalytically active component metal sulfide, which saves the energy consumption during synthesis on the ground on the one hand and retains the activity of the catalyst in the oil shale to the greatest extent on the other hand.

[0035] Beneficial effect 2: In the method for mining oil shale provided by the present invention, the process flow of first injecting an oil-soluble nano-catalyst (metal alkyl dithiocarbamate catalyst) and then injecting a molecular sieve catalyst, on the one hand, utilizes the characteristics of the nano-catalyst with a small particle size that can penetrate into the interior of the rock formation. Combined with the action of the hydrogen donor, the asphaltene generated by in-situ pyrolysis underground is first hydrogenated to generate oil and gas and then produced through the production well, significantly improving the porosity and permeability of the oil shale and opening channels for the penetration of the molecular sieve catalyst in the rock formation in the next step. On the other hand, it utilizes the adjustable B acid and L acid active sites of the molecular sieve catalyst and its advantages in the hydrocracking of oil shale to carry out more efficient in-situ pyrolysis. The combined use of the two catalysts gives full play to their respective advantages. Description of the Drawings

[0036] Figure 1 It is a transmission electron microscope image of the metal alkyl dithiocarbamate catalyst prepared in Example 1 provided by the present invention after pyrolysis. Detailed Embodiments

[0037] The present invention is described in detail below by way of examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Those skilled in the art in this field can make some non-essential improvements and adjustments to the present invention based on the above content of the present invention.

[0038] Example 1

[0039] This embodiment provides a method for preparing an alkyl dithiocarbamide metal catalyst, comprising the following steps:

[0040] Weigh 0.2 mol of diethylamine, 0.16 L of 1.25 mol / L sodium hydroxide solution and 100 ml of tetrahydrofuran, stir at room temperature for 1 h, add 0.3 mol of carbon disulfide, stir at room temperature for 2 h to obtain a sodium diethyldithiocarbamate solution; add a mixed solution containing 0.01 mol of ferric sulfate and 0.07 mol of nickel nitrate, stir at room temperature for 2 h, filter and dry to obtain 34.2 g of a catalyst precursor; at room temperature, dissolve the precursor in 100 g of hydrogenated diesel, and then add 300 g of decahydronaphthalene to obtain an alkyl amidocarbamate metal catalyst, named NH-1.

[0041] Figure 1 is a transmission electron microscope image of the alkyl dithiocarbamate metal catalyst after thermal decomposition. Figure 1 It can be seen that the active component metal sulfide after pyrolysis of the catalyst presents a nano-scale lamellar dispersion morphology.

[0042] The specific pyrolysis process of the alkyl dithiocarbamate metal catalyst is as follows: first, N 2 The air in the tubular furnace was replaced in half an hour, and then the container containing 50g of catalyst NH-1 was placed in a tubular furnace in a nitrogen atmosphere, and the tubular furnace was heated to 300°C under sealed conditions and maintained for 1 hour. After cooling to room temperature, the remaining product in the container was collected and diluted with ethanol. After the remaining product was evenly dispersed in ethanol, it was ultrasonically treated for 20 minutes, and then a small amount of the suspension was taken onto a copper grid with a carbon film on the surface for sample preparation and analysis, and the microscopic morphology of the catalyst decomposition products was observed on a transmission electron microscope.

[0043] Example 2

[0044] Weigh 0.2 mol of dipropylamine, 0.3 L of 1.0 mol / L potassium hydroxide solution and 300 ml of n-hexane, stir at room temperature for 1.5 h, add 0.2 mol of carbon disulfide, stir and react at room temperature for 0.5 h to obtain a solution of potassium dipropyl dithiocarbamate; add 0.1 mol of nickel chloride solution thereto, stir and react at room temperature for 1 h, then filter and dry the filter cake to obtain 40.5 g of a catalyst precursor; at room temperature, dissolve the precursor in 120 g of catalytic diesel, and then add 150 g of tetralin to obtain an alkyl amidocarbamate metal catalyst, named NH-2.

[0045] Example 3

[0046] Weigh 0.2 mol of dihexylamine, 0.03 L of concentrated ammonia water and 300 ml of petroleum ether, stir at room temperature for 2 h, add 0.8 mol of carbon disulfide, stir at room temperature for 1 h to obtain a dihexyldithiocarbamic acid solution; add 0.04 mol of ferric nitrate, 0.02 mol of cobalt sulfate and 0.02 mol of nickel acetate, stir at room temperature for 1 h, filter and dry the filter cake to obtain 56 g of a catalyst precursor; at room temperature, dissolve the precursor in 150 g of petroleum ether, add 60 g of dihydroanthracene to obtain an alkylamino acid metal catalyst, named NH-3.

[0047] Example 4

[0048] Weigh 0.2 mol of dipentylamine, 0.25 L of 1.6 mol / L sodium hydroxide solution and 200 ml of toluene, stir at room temperature for 1.5 h, add 0.4 mol of carbon disulfide, stir and react at room temperature for 1.5 h to obtain a sodium dipentyl dithiocarbamate solution; add 0.05 mol of cobalt nitrate and 0.05 mol of nickel sulfate, stir and react at room temperature for 1.5 h, then filter and dry the filter cake to obtain 51.5 g of a catalyst precursor; dissolve the precursor in 150 g of toluene, and then add 200 g of decahydronaphthalene to obtain an alkyl amidocarbamate metal catalyst, named NH-4.

[0049] Example 5

[0050] Weigh 0.2 mol of diethylamine, 0.125 L of 2.0 mol / L potassium hydroxide solution and 100 ml of tetrahydrofuran, stir at room temperature for 1 h, add 0.3 mol of carbon disulfide, stir at room temperature for 2 h to obtain a potassium diethyldithiocarbamate solution; add a mixed solution of 0.02 mol of ferric acetate and 0.01 mol of basic nickel carbonate, stir at room temperature for 2 h, filter and dry to obtain 23.6 g of a catalyst precursor; at room temperature, dissolve the precursor in 100 g of hydrogenated diesel, and then add 200 g of dihydroanthracene to obtain an alkyl amidocarbamate metal catalyst, named NH-5.

[0051] Example 6

[0052] Weigh 0.2 mol of dibutylamine, 0.12 L of 2.5 mol / L sodium hydroxide solution and 150 ml of DMF, stir at room temperature for 1.5 h, add 0.4 mol of carbon disulfide, and stir at room temperature for 1 h to obtain a sodium dibutyldithiocarbamate solution; add a mixed solution of 0.02 mol of iron nitrate, 0.03 mol of cobalt sulfate, and 0.04 mol of nickel acetate thereto, stir at room temperature for 1 h, then perform suction filtration, and dry the filter cake to obtain 35.1 g of a catalyst precursor; at room temperature, dissolve the precursor in 100 g of catalytic diesel, and then add 200 g of tetralin to obtain an alkyl dithiocarbamate metal catalyst, named NH-6.

[0053] Comparative Example 1

[0054] Weigh 74 g of n-butanol, heat it to 80 °C, add 40 g of sodium hydroxide, maintain the reaction temperature at 80 °C, and react for 0.5 h to obtain sodium butoxide; weigh 160 g of carbon disulfide, add sodium butoxide to carbon disulfide, maintain the reaction temperature at 30 °C, and stir and react for 5 h to obtain an alkyl-substituted thiocarbonate.

[0055] Weigh 50 g of nickel nitrate hexahydrate, 50 g of cobalt nitrate hexahydrate, 44 g of iron nitrate, add 300 mL of distilled water, stir to dissolve, add the alkyl-substituted thiocarbonate, react at 95 °C, and stir for 2 h. Cool the obtained reaction product to room temperature, filter to remove the aqueous phase, and obtain a self-sulfurized oil-soluble multi-metal composite catalyst precursor. Under stirring conditions, add the oil-soluble multi-metal composite catalyst precursor to catalytic cracking diesel with a dispersant, control the ratio of catalytic cracking diesel to multi-metal composite catalyst precursor = 3 / 1 (g / g), and completely dissolve to prepare a solution of the multi-metal composite catalyst precursor, named DB-1.

[0056] Comparative Example 2

[0057] Weigh 74 g of n-butanol, add 40 g of sodium hydroxide, react at room temperature for 0.5 h to obtain sodium butoxide; weigh 160 g of carbon disulfide, add sodium butoxide to carbon disulfide, and stir at room temperature for 5 h to obtain an alkyl-substituted thiocarbonate.

[0058] Weigh 50 g of nickel nitrate hexahydrate, 50 g of cobalt nitrate hexahydrate, 44 g of iron nitrate, add 300 mL of distilled water, stir and dissolve at room temperature, add the alkyl-substituted thiocarbonate, stir and react at room temperature for 2 h, filter the obtained reaction product to remove the aqueous phase, and obtain a catalyst precursor. Under stirring at room temperature, add the catalyst precursor to catalytic cracking diesel with a dispersant, control the ratio of catalytic cracking diesel to multi-metal composite catalyst precursor = 3 / 1 (g / g), and completely dissolve to prepare a multi-metal composite catalyst, named DB-2.

[0059] Comparative Example 3

[0060] This comparative example is similar to Example 1, except that the amount of carbon disulfide used is different. The preparation method of this comparative example specifically comprises the following steps:

[0061] Weigh 0.2 mol of diethylamine, 0.16 L of 1.25 mol / L sodium hydroxide solution and 100 ml of tetrahydrofuran, stir at room temperature for 1 h, add 0.1 mol of carbon disulfide, stir at room temperature for 2 h to obtain a sodium diethyldithiocarbamate solution; add a mixed solution containing 0.01 mol of ferric sulfate and 0.07 mol of nickel nitrate, stir at room temperature for 2 h, filter and dry to obtain 17 g of a catalyst precursor; at room temperature, dissolve the precursor in 100 g of hydrogenated diesel, and then add 300 g of decahydronaphthalene to obtain an alkylamino acid metal catalyst, named DB-3.

[0062] The yield of the catalyst precursor obtained in Comparative Example 3 is about 50% lower than that in Example 1. Since the yield is too low, no corresponding effect verification experiment is performed subsequently.

[0063] Comparative Example 4

[0064] This comparative example is similar to Example 1, except that the amounts of ferric sulfate and nickel nitrate are different. The preparation method of this comparative example specifically comprises the following steps:

[0065] Weigh 0.2 mol of diethylamine, 0.16 L of 1.25 mol / L sodium hydroxide solution and 100 ml of tetrahydrofuran, stir at room temperature for 1 hour, add 0.3 mol of carbon disulfide, stir at room temperature for 2 hours to obtain a sodium diethyldithiocarbamate solution; add a mixed solution containing 0.02 mol of ferric sulfate and 0.14 mol of nickel nitrate, stir at room temperature for 2 hours, filter and dry to obtain 34.4 g of a catalyst precursor; at room temperature, dissolve the precursor in 100 g of hydrogenated diesel, and then add 300 g of decahydronaphthalene to obtain an alkyl dithiocarbamate metal catalyst, named DB-4.

[0066] Compared with Example 1, although the amount of metal source used in Comparative Example 4 is increased, the yield of the obtained catalyst precursor is not increased compared with that in Example 1, resulting in a waste of metal solution. Therefore, no corresponding effect verification experiment is performed subsequently.

[0067] Comparative Example 5

[0068] This comparative example is similar to Example 1, except that the amount of the hydrogen donor decalin is different. The preparation method of this comparative example specifically comprises the following steps:

[0069] Weigh 0.2 mol of diethylamine, 0.16 L of 1.25 mol / L sodium hydroxide solution and 100 ml of tetrahydrofuran, stir at room temperature for 1 hour, add 0.3 mol of carbon disulfide, stir at room temperature for 2 hours to obtain a sodium diethyldithiocarbamate solution; add a mixed solution containing 0.01 mol of ferric sulfate and 0.07 mol of nickel nitrate, stir at room temperature for 2 hours, filter and dry to obtain 34.2 g of a catalyst precursor; at room temperature, dissolve the precursor in 100 g of hydrogenated diesel, and then add 33 g of decahydronaphthalene to obtain an alkyl dithiocarbamate metal catalyst, named DB-5.

[0070] Comparative Example 6

[0071] This comparative example is similar to Example 2, except that the metal source is different. The preparation method of this comparative example specifically includes the following steps:

[0072] Weigh 0.2 mol of dipropylamine, 0.3 L of 1.0 mol / L potassium hydroxide solution and 300 ml of n-hexane, stir at room temperature for 1.5 h, add 0.2 mol of carbon disulfide, stir and react at room temperature for 0.5 h to obtain a potassium dipropyl dithiocarbamate solution; add 0.1 mol of ammonium molybdate solution, stir and react at room temperature for 1 h, then filter and dry the filter cake to obtain 79.7 g of a catalyst precursor; at room temperature, dissolve the precursor in 120 g of catalytic diesel, and then add 150 g of tetralin to obtain an alkyl dithiocarbamate metal catalyst, named DB-6.

[0073] Effect verification experiment

[0074] Karamay oil shale was used. 100 g of oil shale was weighed and placed in a container and placed in a tube furnace. The catalyst solutions in the above embodiments and comparative examples were added (the amount added was 0.1 g in terms of metal element). N was purged before each experiment. 2 After half an hour, the tube furnace is heated to 450°C, and the heating is stopped after 2 days. A condenser is set at the outlet to collect the gas phase product G1. After the reaction is completed and the temperature is lowered, the container containing the oil shale is taken out and filtered to obtain the liquid phase product L1 and the remaining solid product S1. Then 5g of HZSM-5 molecular sieve catalyst is added to S1. During the addition process, the molecular sieve catalyst can be mixed with anhydrous ethanol to form a suspension, and then the suspension is evenly sprayed into the product S1. The S1 after the catalyst is added is placed in a container and placed in a tube furnace. N is first purged at 80°C. 2After half an hour until the ethanol is completely volatilized, the temperature is continued to rise to 450°C, and the heating is stopped after maintaining for 2 days. The gas phase product G2, the liquid phase product L2, and the remaining solid product S2 are collected again according to the above method. At the same time, a parallel experiment 1 is set up. Compared with the above experimental process, only 100g of oil shale is omitted in parallel experiment 1, and other operations are the same. Finally, the gas phase product G0, the liquid phase product L0, and the remaining solid product S0 are collected.

[0075] When only molecular sieve catalyst is added, the specific steps are as follows: 10 g of HZSM-5 molecular sieve catalyst is added to 100 g of oil shale sample, and then placed in a container and placed in a tube furnace, and N is purged at 80 °C. 2 Half an hour, then the tube furnace is heated to 450°C and kept for 2 days before stopping heating. A condenser is set at the outlet to collect the gas phase product G2'. After the reaction is finished and the temperature is lowered, the container containing the oil shale is taken out and filtered to obtain the liquid phase product L2' and the remaining solid product S2'. At the same time, a parallel experiment 2 is set up. Compared with the above experimental process, only 100g of oil shale is omitted in the parallel experiment 2, and other operations are the same. Finally, the gas phase product G0', the liquid phase product L0', and the remaining solid product S0' are collected.

[0076] Blank test:

[0077] Karamay oil shale was used. 100 g of oil shale was weighed and placed in a container and placed in a tubular furnace. N 2 The air in it is replaced in half an hour, and then the temperature of the tubular furnace is raised to 450°C. After maintaining it for 2 days, the heating is stopped, and a condensing device is set at the outlet to collect the gaseous product G1" (G1" is the gaseous phase yield of the blank experiment). After the reaction is completed and the temperature is lowered, the container with the oil shale is taken out and filtered to obtain the liquid product L1" (L1" is the liquid phase yield of the blank experiment) and the remaining solid product S1" (S1" is the semi-coke yield of the blank experiment).

[0078] The obtained product properties are shown in Table 1, and the calculation formulas of each index are as follows:

[0079] Semi-coke yield = semi-coke output / (semi-coke output + liquid phase output + gas phase output) × 100%

[0080] Oil production rate = liquid phase production / (semi-coke production + liquid phase production + gas phase production) × 100%

[0081] Gas yield = gas phase yield / (semi-coke yield + liquid phase yield + gas phase yield) × 100%

[0082] The calculation formulas for the semi-coke yield, liquid phase yield and gas phase yield in each embodiment and comparative example are as follows:

[0083] Semi-coke output = Q S2 -Q S0

[0084] Liquid phase yield = Q L1 +Q L2 -Q L0

[0085] Gas phase production = Q G1 +Q G2 -Q G0

[0086] The calculation formula for the semi-coke yield, liquid phase yield and gas phase yield in the case of adding only HZSM-5 molecular sieve catalyst is:

[0087] Semi-coke output = Q S2 '-Q S0 '

[0088] Liquid phase yield = Q L2 '-Q L0 '

[0089] Gas phase production = Q G2 '-Q G0 '

[0090] Wherein, Q is the mass of each product.

[0091] Table 1 Comparison of properties of oil shale pyrolysis products under different catalyst conditions

[0092]

[0093]

[0094] It can be seen from the data in the above table that the oil yield of pyrolyzing oil shale by adding the alkyl aminosulfonic acid metal catalyst provided by the present invention and the HZSM-5 molecular sieve catalyst together> the oil yield of pyrolyzing oil shale by adding only the HSZM-5 molecular sieve catalyst> the oil yield of pyrolyzing shale oil without adding a catalyst.

[0095] When two catalysts are added to act together: the catalysts in Examples 1-6 have little difference in their effects on the pyrolysis properties of oil shale. The oil yield of Comparative Example 1 is slightly lower than that of Examples 1-6. Analysis shows that this is because Comparative Example 1 uses a self-sulfurized oil-soluble catalyst prepared by the prior art method. In the process of heating it together with shale oil, it has been pyrolyzed to generate metal sulfides before reaching the pyrolysis temperature of shale oil. Affected by surrounding impurities, some active sites are inactivated, affecting the catalytic activity after reaching the pyrolysis temperature of shale oil.

[0096] The oil yield of Comparative Example 2 is much lower than that of Comparative Example 1 and Examples 1-6. Analysis shows that the reason is that the heating step in Comparative Example 1 is reduced in the synthesis process of the entire catalyst in Comparative Example 2, so no stable bond energy is formed between the metal and the thiocarbonate. Although there is no heating step in Examples 1-6, the N atom in the secondary amine has a lone pair of electrons and the metal ion has an empty orbital, which can form a stable cyclic ion. As the temperature of the shale oil increases, a bond between the metal and sulfur is gradually formed first, and then the catalytic active component metal sulfide is thermally decomposed to generate, on the one hand, the energy consumption in the early stage of synthesizing the catalyst is saved, and on the other hand, the activity of the catalyst in the oil shale is retained to the greatest extent.

[0097] In Comparative Example 5, the amount of hydrogen donor added was less than the limit value, which affected the hydrocracking activity of the catalyst.

[0098] In Comparative Example 6, the metal source is a molybdenum source, and the catalyst activity is lower than that of iron, cobalt, and nickel. Analysis shows that molybdenum has a large coordination number, and due to the effect of steric hindrance, the cyclic ion formed by it and the organic ligand is unstable, which affects the hydrocracking activity of the catalyst.

[0099] Of course, the present invention may have many other embodiments and variations thereof. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and variations based on the present invention, but these corresponding changes and variations should all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing an alkyl dithiocarbamate metal catalyst, It is characterized in that The steps include: (1) after uniformly mixing a secondary amine, an alkali solution and a first organic solvent, adding carbon disulfide to react to obtain an alkyl amino dithiocarboxylic acid or a salt thereof; (2) adding a metal source to the alkylamino acid or its salt to react, and after the reaction is completed, separating and drying to obtain a catalyst precursor; (3) dissolving the catalyst precursor in a second organic solvent, and then mixing it with a hydrogen donor to obtain the alkyl dithiocarbamate metal catalyst; The entire preparation process is carried out at room temperature, the molar ratio of the secondary amine to the carbon disulfide is 1:(1-4); the molar ratio of the metal source, calculated as metal element, to the metal source is 1:(0.3-0.5); The metal source is selected from at least one of an iron source, a cobalt source and a nickel source; The mass ratio of the catalyst precursor to the hydrogen donor is 1:(1-10).

2. The preparation method according to claim 1, It is characterized in that The molar ratio of the secondary amine to the solute in the alkali solution is 1:(1-2).

3. The preparation method according to claim 1, It is characterized in that The hydrogen donor is selected from any one of tetralin, dihydroanthracene and decalin.

4. The preparation method according to claim 1, It is characterized in that The secondary amine is selected from any one of diethylamine, dipropylamine, di-n-butylamine, dipentylamine and dihexylamine.

5. The preparation method according to claim 1, It is characterized in that The first organic solvent is selected from any one of tetrahydrofuran, toluene, DMF, n-hexane and petroleum ether; and / or The second organic solvent is selected from any one of hydrogenated diesel, catalytic diesel, waste grease, petroleum ether and toluene.

6. The preparation method according to claim 1, It is characterized in that The alkali solution is selected from any one of sodium hydroxide solution, potassium hydroxide solution and concentrated ammonia solution.

7. The preparation method according to claim 1, It is characterized in that The nickel source is selected from any one of nickel nitrate, nickel acetate, basic nickel carbonate, nickel chloride and nickel sulfate; and / or The cobalt source is selected from any one of cobalt nitrate, cobalt acetate, basic cobalt carbonate, cobalt chloride and cobalt sulfate; and / or The iron source is selected from any one of ferric nitrate, ferric acetate, ferric chloride and ferric sulfate.

8. Use of the alkyl amidosulfuric acid metal catalyst prepared by the preparation method of the alkyl amidosulfuric acid metal catalyst according to any one of claims 1 to 7 in in-situ mining of oil shale.

9. A method for mining oil shale, It is characterized in that The method comprises the following steps: injecting an alkyl amino disulfide metal catalyst into the ground through an injection well for in-situ mining, then heating it to 350-600° C. for in-situ conversion for 1-60 days, and then extracting the oil and gas generated by pyrolysis through a production well; Wherein, the alkyl dithiocarboxylic acid metal catalyst is prepared by the preparation method of the alkyl dithiocarboxylic acid metal catalyst according to any one of claims 1 to 7.

10. The method for mining oil shale according to claim 9, It is characterized in that After the production well is produced, the process also includes injecting a molecular sieve catalyst underground to continue deep pyrolysis.

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