A highly dispersed iron-based catalyst for hydrogenation and liquefaction of solid hydrocarbon raw materials and its preparation method

Abstract

The present invention discloses a highly dispersed iron-based catalyst for hydrogenation and liquefaction of solid hydrocarbon raw materials and a preparation method thereof. The preparation method of the iron-based catalyst comprises the following steps: S1, preparing a solution of an iron salt and a solution of a precipitant, and mixing them with additives to obtain mixed slurries 1 and 2 respectively; S2, preheating the working gas and passing it into a suspension forming tower to form an upward airflow; S3, passing the mixed slurry 1 and the solution of the precipitant, and the mixed slurry 2 and the solution of the iron salt through a pumping device respectively to form pressurized reaction raw materials 1 and 2; S4, sending the pressurized reaction raw materials 1 and 2 into the suspension forming tower in the form of droplets, and spraying them into the upper space of the suspension forming tower opposite to each other, so that the pressurized reaction raw materials 1 and 2 collide and react to generate catalyst precursor droplets, obtaining the downward material of the suspension tower, contacting with the upward airflow in a cross-flow manner, undergoing a drying, roasting and / or activation process, and forming a catalyst powder. The catalyst powder prepared by the method of the present invention can improve the hydrogenation conversion efficiency of solid hydrocarbon raw materials.

Description

Technical Field

[0001] The present invention relates to a highly dispersed iron-based catalyst for hydrogenation and liquefaction of solid hydrocarbon raw materials and a preparation method thereof, and is in the field of energy and chemical industry. Background Art

[0002] The hydroliquefaction of solid hydrocarbon feedstocks is the process of producing liquefied oil (liquid fuel) from solid hydrocarbon feedstocks. The key step is the hydrogenation of the feedstock slurry (a mixture of solid hydrocarbon feedstock, solvent oil, and catalyst) in a reactor. Under the hydrogenation reaction conditions (high temperature, high pressure, and catalysis), some chemical bonds in the macromolecular structure of the solid hydrocarbon feedstock are thermally cracked, generating free radicals. These free radicals combine with active hydrogen atoms to form smaller molecules, including the liquid fuel. The catalyst is one of the key factors influencing the effectiveness of coal liquefaction.

[0003] Catalysts for the hydrogenation and liquefaction of solid hydrocarbon feedstocks can be divided into three major categories. The first category is precious metal catalysts, such as cobalt (Co)-based, molybdenum (Mo)-based, and nickel (Ni)-based catalysts. These catalysts have high catalytic activity, but are expensive and are discharged with waste residue, polluting the environment. They are also difficult to recycle and have high costs. The second category of catalysts is metal halide catalysts, such as ZnCl2 and SnCl2. These catalysts are acidic catalysts that have the ability to catalyze cracking, but they have a strong corrosive effect on equipment. The third category of catalysts is iron-based catalysts. Although iron-based catalysts do not have the highest catalytic activity, their activity is also obvious. They are also inexpensive, and the iron element does not pollute the environment and does not need to be recycled, making them the catalysts with the most promising industrial prospects.

[0004] Iron-based catalysts primarily come from two sources: nature and chemical synthesis. Natural iron-containing ores (including pyrite, limonite, and pyrrhotite) are not rare, but effectively and efficiently grinding these ores into ultrafine powders and then mixing them with solid hydrocarbon feedstock powders to achieve uniform dispersion for optimal catalytic activity presents significant challenges. Furthermore, the chemical composition and structure of natural iron-containing minerals often do not align well with the optimal active phase for hydroliquefaction catalysts. Consequently, high addition levels, typically exceeding 3 wt.%, are typically required.

[0005] Through chemical synthesis methods, iron-based products with specific physical phases at the micron or even nanometer level can be obtained. When used for hydrogenation and liquefaction of solid hydrocarbon raw materials, it is easy to achieve high dispersion of the catalyst on the inner and outer surfaces of the coal powder, so that the catalyst activity and utilization rate are in the best state. In order to meet the purpose of ultrafine and high dispersion, freshly synthesized iron-based catalysts or their precursors are usually highly dispersed in the solvent as colloids or nanoparticles, which makes their desolvation difficult. In-situ loading or flocculation are methods developed to effectively remove solvents and obtain ultrafine and highly dispersed catalysts. Chinese patent application CN202210055408.3 discloses a bifunctional catalyst in which an acidic WO3-ZrO2 carrier is loaded with metals such as Fe, Ni or Pd, which promotes the hydrocracking of waste plastics by utilizing the synergistic effect of acidic sites and metal sites. Chinese patent application CN200310053377.5 discloses a supported iron-based catalyst and its preparation method. This method uses FeSO4 solution as the iron source, coal powder as the carrier, and an alkaline solution containing hydroxide ions as the precipitant. The mixture is stirred to prepare a coal hydroliquefaction catalyst containing the active component γ-FeOOH. Chinese patent application CN201611041484.X discloses a biochar-supported Mo, W, Fe, or Ni metal catalyst for the catalytic hydroliquefaction of corn straw. However, due to the low catalyst activity, the required reaction conditions are harsh (approximately 400°C and 20 MPa).

[0006] The conventional precipitation method currently used has many catalyst preparation steps (precipitation, filtration, drying, calcination and / or activation, molding), uneven material contact, and the resulting catalyst has uneven texture and structure and low dispersion, which urgently needs to be improved. Summary of the Invention

[0007] The present invention aims to provide an iron-based catalyst for hydrogenating and liquefying solid hydrocarbon feedstocks and a preparation method thereof. The prepared catalyst powder has the characteristics of uniform particle size, texture structure, and degree of dispersion, and is easy to achieve high dispersion in the reaction slurry, thereby improving the hydrogenation conversion efficiency of the solid hydrocarbon feedstock.

[0008] The method for preparing an iron-based catalyst for hydrogenating and liquefying solid hydrocarbon raw materials provided by the present invention comprises the following steps:

[0009] S1, preparing a solution of an iron salt and a solution of a precipitant, and mixing them with additives to obtain mixed slurry 1 and mixed slurry 2 respectively;

[0010] S2, the working gas is preheated and introduced into the suspension forming tower to form an upward airflow;

[0011] S3, the mixed slurry 1 and the solution of the precipitant, and the mixed slurry 2 and the solution of the iron salt are respectively pumped through a pumping device to form pressurized reaction raw material 1 and pressurized reaction raw material 2;

[0012] S4. The pressurized reaction raw material 1 and the pressurized reaction raw material 2 are fed into the suspension forming tower in the form of droplets and sprayed into the upper space of the suspension forming tower opposite to each other. The pressurized reaction raw material 1 and the pressurized reaction raw material 2 collide and react to generate catalyst precursor droplets, and the downstream material of the suspension tower is obtained. The material is in cross-flow contact with the upward air flow, undergoes a drying, roasting and / or activation process, and forms a catalyst powder as the iron-based catalyst for hydrogenation and liquefaction of the solid hydrocarbon feedstock.

[0013] In the above preparation method, in step S1, the iron salt is at least one of ferric sulfate, ferric chloride, ferric nitrate, ferrous sulfate, ferrous chloride, ferric acetate or ferrous acetate aqueous solution;

[0014] The precipitant is at least one of ammonia water, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, ammonium carbonate, ammonium bicarbonate, sodium sulfide, potassium sulfide, calcium hydroxide and barium hydroxide;

[0015] Using water to prepare the solution of the iron salt and the solution of the precipitant;

[0016] The concentration of the iron salt solution is 10-35%, and the concentration of the precipitant solution is 10-35%.

[0017] In the above preparation method, in step S1, the additive is at least one of coal powder, coal char, silica gel, pumice, diatomaceous earth, montmorillonite, kaolin, clay, silica sol, alumina sol, fly ash, coal slag, activated carbon, carbon nanotubes, zeolite, molecular sieve, natural ore, metal-organic framework, alumina, and oxides of the following metals and salts thereof;

[0018] Titanium, zirconium, cerium, zinc, manganese, nickel, molybdenum and tungsten.

[0019] In the above preparation method, in step S2, the working gas is at least one of air, nitrogen, hydrogen, hydrogen sulfide, carbon monoxide and flue gas;

[0020] The working gas is introduced from the lower part of the suspension forming tower after being preheated;

[0021] The working gas is preheated to 300-600°C.

[0022] In the above preparation method, in step S3, the mass ratio of the pressurized reaction raw material 1 to the pressurized reaction raw material 2 is 0.5 to 3:1;

[0023] The atomizing device is a pressure atomizing device, a centrifugal atomizing device, a pneumatic atomizing device or an ultrasonic atomizing device;

[0024] At least two atomizing devices are arranged opposite to each other so that the sprayed droplets converge in the same area;

[0025] The diameter of the mist droplets is controlled to be less than 1.2 mm.

[0026] In the above preparation method, in step S3, the method further includes the following treatment steps on the dust-containing tail gas discharged from the gas outlet of the suspension forming tower:

[0027] The catalyst fine powder entrained in the dust-containing tail gas is removed by an exhaust dust removal system, and the catalyst fine powder is mixed with the catalyst powder to serve as the iron-based catalyst for hydrogenation and liquefaction of the solid hydrocarbon feedstock;

[0028] The exhaust dust removal system may be any device commonly used in the art, such as a single-stage or multi-stage cyclone dust removal system, a bag dust removal system, an electrostatic precipitator system, or a combination thereof;

[0029] The dust-removed tail gas after the catalyst fine powder is removed is recycled or discharged after tail gas purification treatment;

[0030] The following tail gas treatment devices can be used for treatment: one or more combinations of heat exchangers, condensation recovery devices, absorption towers or catalytic combustion equipment.

[0031] The iron-based catalyst for hydrogenation and liquefaction of solid hydrocarbon raw materials provided by the present invention can be used to catalyze the hydrogenation and liquefaction of solid hydrocarbon raw materials;

[0032] The solid hydrocarbon raw materials are coal of different metamorphic degrees (such as lignite, bituminous coal, etc.), biomass (such as crop waste, plants, biological excrement, etc.) and industrial and domestic waste (such as waste tires, waste plastics, etc.).

[0033] The preparation method provided by this invention completes catalyst synthesis, drying, calcination, and activation in a single step in a suspension molding tower, shortening the process. Components, in the form of droplets, collide and contact, ensuring efficient mixing and controllable molding. Solid-phase suspension drying and calcination produce an ultrafine, highly dispersed catalyst.

[0034] The present invention provides a method for preparing a highly dispersed iron-based catalyst for the hydrogenation and liquefaction of solid hydrocarbon feedstocks. The feedstocks are sprayed into a suspension forming tower in opposite directions, and iron salts, precipitants, and / or additives are collided and mixed to form a catalyst precursor. The feedstocks then descend in the form of droplets, countercurrently contacting an ascending hot air stream, thereby forming an axial temperature gradient in the suspension forming tower. During their descent, the suspended droplets undergo desolvation, calcination, and / or activation processes to produce catalyst powders with the desired particle size distribution and composition. The particle size distribution of the catalyst powder is controlled by adjusting the droplet size, and the catalyst powder phase is controlled by adjusting the temperature gradient and atmosphere within the tower. The present invention has the characteristics of a simple preparation process, high raw material utilization, and low water consumption, effectively reducing the production cost of the catalyst. The suspended droplet state during the forming process forms an ultrafine, highly dispersed phase. The catalyst powder prepared by the method of the present invention has the characteristics of uniform particle size, texture, and dispersion, making it easy to achieve high dispersion in the reaction slurry, thereby improving the hydrogenation conversion efficiency of the solid hydrocarbon feedstock. DETAILED DESCRIPTION

[0035] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0036] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0037] The method for preparing a highly dispersed iron-based catalyst for hydrogenation and liquefaction of solid hydrocarbon raw materials of the present invention comprises the following steps:

[0038] (1) preparing an iron salt solution and a precipitant solution;

[0039] (2) mixing the additive and the iron salt solution or precipitant solution in step (1) in a mixer to obtain a mixed slurry;

[0040] (3) the mixed slurry in step (2) and the precipitant solution or iron salt solution in step (1) are pumped through a pumping device to form a pressurized material 1 and a pressurized material 2;

[0041] (4) feeding the pressurized materials 1 and 2 in step (3) into an atomizing system, spraying them into the upper space of a suspension forming tower opposite to each other, and performing collision mixing to form catalyst precursor droplets, which serve as the downstream material of the suspension tower;

[0042] (5) After preheating the working gas, it is passed into the suspension forming tower to form an upward airflow in the tower;

[0043] (6) In the suspension forming tower, the descending material of step (4) contacts the ascending airflow of step (5), forming an axial temperature gradient of the suspension forming tower;

[0044] (7) The descending material from step (4) comes into contact with the working airflow from step (5) during the process of suspension and descending, undergoes drying, roasting and / or sulfurization, and forms catalyst powder, which falls to the bottom of the tower; the ascending airflow carries the catalyst fine powder, forming dusty tail gas, which is discharged from the top of the tower;

[0045] (8) introducing the catalyst powder falling at the bottom of the tower in step (7) into a product collection device and storing it in an inert environment;

[0046] (9) introducing the dust-laden tail gas from step (7) into a tail gas dust removal system, collecting the catalyst fine powder, and obtaining the dust-free tail gas;

[0047] (10) The dust-removed tail gas from step (9) is introduced into a tail gas treatment device for further purification and then reused or discharged.

[0048] In some preferred embodiments, the iron salt solution in step (1) includes one or more combinations of aqueous solutions of ferric sulfate, ferric chloride, ferric nitrate, ferrous sulfate, ferrous chloride, ferric acetate, and ferrous acetate.

[0049] In some preferred embodiments, in step (1), the concentration of the iron salt solution is 10 to 35 wt.%.

[0050] In some preferred embodiments, in step (1), the precipitant is one or more combinations of ammonia water, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, ammonium carbonate and ammonium bicarbonate, sodium sulfide, potassium sulfide, calcium hydroxide and / or barium hydroxide.

[0051] In some preferred embodiments, in step (1), the concentration of the precipitant solution is 10 to 35 wt.%.

[0052] In some preferred embodiments, in step (2), the additive is one or more combinations of coal powder, coal char, silica gel, pumice, diatomaceous earth, montmorillonite, kaolin, clay, silica sol, aluminum sol, fly ash and coal slag, activated carbon, carbon nanotubes, zeolite, molecular sieve, natural ore, metal organic framework, alumina, titanium / zirconium / cerium / zinc / manganese / nickel / molybdenum / tungsten oxides and salts thereof, etc.

[0053] In some preferred embodiments, in step (2), the mass ratio of the iron salt solution or the precipitant solution to the additive is 2 to 4:1.

[0054] In some preferred embodiments, the mixed slurry is formed in step (2) in the following three ways:

[0055] i) first adding the optional iron salt solution or the optional precipitant solution into the mixer, starting the device, then adding the optional additives and stirring for 0.1 to 3 hours;

[0056] ii) first adding the optional additives into the mixer, starting the device, then adding the optional iron salt solution or the optional precipitant solution, and stirring for 0.1 to 3 hours;

[0057] iii) starting the device, adding the optional iron salt solution or the optional precipitant solution and the optional additives into the mixer simultaneously, and stirring for 0.1 to 3 hours.

[0058] In some preferred embodiments, in step (2), the mixer is any device conventionally used in the art, such as one or more combinations of a stirring mixer, a pipeline mixer, a jet mixer, a forced circulation mixer, a static mixer, a kneader and a rotary kiln.

[0059] In some preferred embodiments, in step (4), the ejection mass ratio of the belt press 1 to the belt press 2 is 0.5 to 3:1.

[0060] In some preferred embodiments, in step (4), the atomizer is any device conventionally used in the art, such as one or more combinations of pressure, centrifugal, pneumatic and ultrasonic atomizers; further, there are at least two atomizers, and the spray droplets converge in the same area; further, the diameter of the nozzle is adjusted according to the properties of the material to control the droplet diameter to be below 1.2 mm.

[0061] In some preferred embodiments, in step (5), the working gas is one or more combinations of air, nitrogen, hydrogen, hydrogen sulfide, carbon monoxide, and flue gas, and the hot gas inlet temperature is 300-600°C.

[0062] In some preferred embodiments, in step (8), the inert environment is an inert atmosphere, a water seal, a solvent oil seal, or a wax seal.

[0063] In some preferred embodiments, in step (9), the tail gas dust removal system is any device commonly used in the art, such as one or more combinations of single-stage or multi-stage cyclone dust removal, bag dust removal, and electrostatic precipitator.

[0064] In some preferred embodiments, in step (10), the tail gas treatment device is any device conventionally used in the art, such as one or more combinations of a heat exchanger, a condensation recovery device, an absorption tower or a catalytic combustion device.

[0065] In some preferred embodiments, the solid hydrocarbon feedstock hydroliquefaction catalyst is used in the hydroliquefaction process of coal with different metamorphic degrees (such as lignite, bituminous coal, etc.), biomass (such as crop waste, plants, biological excrement, etc.) and industrial and domestic waste (such as waste tires, waste plastics, etc.).

[0066] The technical solution of the present invention is further described below in conjunction with the following examples. However, it should be understood that the protection scope of the present invention is not limited to these embodiments.

[0067] Comparative Example 1: Preparation of Catalyst D1

[0068] 182.8 kg of ferrous sulfate heptahydrate was added to 817.2 kg of water to prepare a 10 wt.% ferrous sulfate solution, and then 500 kg of aluminum oxide was added to obtain a mixed slurry. 300 kg of water was added to 200 kg of 25 wt.% ammonia solution to prepare a 10 wt.% ammonia solution. The mixed slurry and the ammonia solution were pumped co-currently into an acid-base mixing kettle to obtain a precipitated slurry. The precipitated slurry was washed, filtered, dried, and calcined to obtain Catalyst D1.

[0069] Example 1: Preparation of Catalyst C1

[0070] Add 182.8 kg of ferrous sulfate heptahydrate to 817.2 kg of water to prepare a 10 wt.% ferrous sulfate solution; add 300 kg of water to 200 kg of A 10 wt. % ammonia solution is prepared in 25 wt. % ammonia water; 500 kg of aluminum oxide is added to a stirring mixer, followed by 1000 kg of ferrous sulfate solution, the device is started, and mixing is carried out for 0.5 h to obtain a mixed slurry; the mixed slurry and the 10 wt. % ammonia solution are pumped into a pressure atomizer at the top of a suspension forming tower in a specified proportion, sprayed into the upper space of the suspension forming tower through opposing double nozzles (2.0 mm diameter) to form droplets of approximately 1 mm, which are impact-mixed to form a descending material in the suspension forming tower; air is heated to 300° C. and introduced into the bottom of the suspension forming tower to form an upward airflow in the tower, which is countercurrently contacted with the descending material in the suspension forming tower, undergoes synthesis, drying, and roasting processes, and obtains a catalyst product (A1) and dust-laden tail gas at the bottom of the tower; the dust-laden tail gas is introduced into a secondary cyclone separation system at the top of the suspension forming tower to collect catalyst fine powder (B1) and dedusted tail gas; the dedusted tail gas is introduced into a condensation recovery device to condense water vapor and then reuse the air. Catalysts A1 and B1 were uniformly mixed to obtain catalyst C1, which was stored in a nitrogen atmosphere.

[0071] Example 2: Preparation of Catalyst C2

[0072] 200 kg of ferric chloride was added to 800 kg of water to prepare a 20 wt.% ferric chloride solution; 150 kg of sodium carbonate was added to 600 kg of water to prepare a 20 wt.% sodium carbonate solution; 1000 kg of ferric chloride was added to a rotary kiln, and 250 kg of kaolin was added. The device was started and mixed for 0.1 h to obtain a mixed slurry; the mixed slurry and the 20 wt.% sodium carbonate solution were pumped into a centrifugal atomizer at the top of a suspension forming tower in a prepared ratio, and then passed through three opposing nozzles (1.4 mm diameter) to form a slurry. The process involves spraying the mixture into the upper space of a suspension forming tower to form 0.7 mm droplets, where the materials collide and mix, forming a downward flow in the suspension forming tower. A 20% hydrogen sulfide / nitrogen mixture is heated to 450°C and introduced from the bottom of the suspension forming tower, forming an upward flow in the tower. This flow countercurrently contacts the downward flow in the suspension forming tower, undergoing drying, calcination, and activation. A catalyst product (A2) and dust-laden tail gas are obtained at the bottom of the tower. The dust-laden tail gas is introduced into a bag dust removal and separation system at the top of the suspension forming tower to collect catalyst fine powder (B2) and dedusted tail gas. The dedusted tail gas is introduced into an alkaline solution absorption tower for purification and reuse. Catalysts A2 and B2 are uniformly mixed to obtain catalyst C2, which is stored in solvent oil.

[0073] Example 3: Preparation of Catalyst C3

[0074] 350 kg of ferric acetate was added to 650 kg of water to prepare a 35 wt.% ferric acetate solution; 270 kg of sodium hydroxide was added to 480 kg of water to prepare a 35 wt.% sodium hydroxide solution; a kneader was started, and 750 kg of sodium hydroxide solution and 250 kg of fly ash were added at the same time and mixed for 1.5 hours to obtain a mixed slurry; the mixed slurry and the 35 wt.% ferric acetate solution were fed into an ultrasonic atomizer at the top of a suspension forming tower in a prepared ratio through a pumping device and passed through four opposing nozzles (1.0 mm The catalyst is sprayed into the upper space of the suspension forming tower, forming approximately 0.5 mm droplets. The materials collide and mix, forming the descending material in the suspension forming tower. Flue gas at a temperature of 600°C is introduced from the bottom of the suspension forming tower, forming an upward flow in the tower. It countercurrently contacts the descending material in the suspension forming tower, undergoes drying and roasting, and produces catalyst product (A3) and dust-laden tail gas at the bottom of the tower. The dust-laden tail gas is introduced into the electrostatic precipitator system at the top of the suspension forming tower to collect catalyst fine powder (B3) and dedusted tail gas. The dedusted tail gas is sequentially introduced into a heat exchanger tower and then purified in an alkali liquid absorption tower before being discharged. Catalysts A3 and B3 are uniformly mixed to produce catalyst C3, which is then liquid-sealed in paraffin wax.

[0075] Example 4: Preparation of Catalyst C4

[0076] 100 kg of ferric nitrate and 100 kg of ferric sulfate were added to 600 kg of water to prepare a 25 wt.% iron salt solution; 50 kg of sodium sulfide and 50 kg of sodium hydroxide were added to 400 kg of water to prepare a 20 wt.% precipitant solution; 200 kg of molecular sieve and 100 kg of kaolin were added to a stirring mixer, and 500 kg of A 20 wt.% concentration precipitant solution is started, the device is started, and mixed for 3 hours. The slurry is then added to a mixer and mixed for 1 hour. The resulting mixed slurry and a 25 wt.% concentration ferric nitrate solution are pumped into a pneumatic atomizer at the top of a suspension forming tower in a specified ratio, and sprayed into the upper space of the suspension forming tower through opposing dual nozzles (0.5 mm diameter) to form approximately 0.3 mm droplets. The materials collide and mix to form a downward flow of material in the suspension forming tower. Nitrogen at a temperature of 500° C. is introduced from the bottom of the suspension forming tower to form an upward flow in the tower. The nitrogen gas is countercurrently contacted with the downward flow of material in the suspension forming tower, undergoes a drying and roasting process, and obtains a catalyst product (A4) and dust-laden tail gas at the bottom of the tower. The dust-laden tail gas is sequentially introduced into a secondary cyclone separation system and an electrostatic precipitator system at the top of the suspension forming tower to collect catalyst fine powder (B4) and dust-depleted tail gas. The dust-depleted tail gas is sequentially introduced into a heat exchanger and a condensation recovery device to recover water vapor and nitrogen for reuse. Catalysts A4 and B4 were uniformly mixed to obtain catalyst C4, which was stored in water.

[0077] Example 5: Preparation of Catalyst C5

[0078] 100 kg of ferric sulfate was added to 400 kg of water to prepare a 20 wt.% ferric sulfate solution; 200 kg of ammonium carbonate was added to 800 kg of water to prepare a 20 wt.% ammonium carbonate solution; the device was started, 200 kg of coal powder and 500 kg of 20 wt.% ferric sulfate solution were introduced into the pipeline mixer and mixed for 0.1 h to obtain a mixed slurry; the mixed slurry and the 20 wt.% ammonium carbonate solution were respectively fed into the centrifugal atomizer and the pressure atomizer on the upper part of the suspension forming tower through a pumping device, and then the mixture was discharged through four opposing nozzles. The catalyst (1.0 mm diameter) is sprayed into the upper space of the suspension forming tower, forming approximately 0.7 mm droplets. The materials collide and mix, forming the downward flow of the suspension forming tower. 10% carbon monoxide / hydrogen gas at a temperature of 350°C is introduced from the bottom of the suspension forming tower, forming an upward flow in the tower. This gas countercurrently contacts the downward flow of the suspension forming tower, undergoes drying and roasting, and produces catalyst product (A5) and dust-laden tail gas at the bottom of the tower. The dust-laden tail gas is introduced into a secondary cyclone separation system at the top of the suspension forming tower to collect catalyst fine powder (B5) and dedusted tail gas. The dedusted tail gas is introduced into an absorption tower, purified, and then reused. Catalysts A5 and B5 are uniformly mixed to produce catalyst C5, which is then liquid-sealed in solvent oil.

[0079] Application Example 1: Catalytic Hydrogenation and Liquefaction of Solid Hydrocarbon Raw Materials

[0080] The catalysts prepared in the comparative examples and examples 1-5 of the present invention catalyzed solid hydrocarbon raw materials A (lignite) / B (straw) / C (waste plastics). The properties of the raw materials are shown in Table 1.

[0081] The reaction conditions are: pressure 3-6 MPa, temperature 400-450°C, residence time 30-240 min, elemental S / Fe = 1 / 1, catalyst addition amount 1%-3% (mass fraction) Fe daf .

[0082] The conditions and results of hydrogenation liquefaction of solid hydrocarbon feedstock by various catalysts are shown in Table 2.

[0083] Table 1 Properties of several solid hydrocarbon raw materials

[0084]

[0085] Table 2 Hydroliquefaction conditions and results of several solid hydrocarbon feedstocks using catalysts obtained in Examples 1-5

[0086]

[0087] As can be seen from the data in Table 2, the highly dispersed iron-based catalyst for hydrogenation and liquefaction of solid hydrocarbon feedstocks provided by the present invention can be easily dispersed in the reaction slurry, thereby improving the hydrogenation conversion rate of the solid hydrocarbon feedstock and having a high oil yield. Moreover, the preparation process is simple, which can effectively reduce the production cost of the catalyst.

Claims

1. A method for preparing an iron-based catalyst for hydrogenating and liquefying solid hydrocarbon feedstock, comprising the following steps: S1, preparing a solution of an iron salt and a solution of a precipitant, and mixing them with additives to obtain mixed slurry 1 and mixed slurry 2 respectively; S2, the working gas is preheated and introduced into the suspension forming tower to form an upward airflow; In step S2, the working gas is at least one of air, nitrogen, hydrogen, hydrogen sulfide and carbon monoxide; The working gas is introduced from the lower part of the suspension forming tower after being preheated; The working gas is preheated to 300-600°C; S3, the mixed slurry 1 and the solution of the precipitant, and the mixed slurry 2 and the solution of the iron salt are respectively pumped through a pumping device to form pressurized reaction raw material 1 and pressurized reaction raw material 2; In step S3, the mass ratio of the pressurized reaction raw material 1 to the pressurized reaction raw material 2 is 0.5-3:1; S4, feeding the pressurized reaction raw material 1 and the pressurized reaction raw material 2 into the suspension forming tower in the form of droplets, spraying them into the upper space of the suspension forming tower opposite to each other, causing the pressurized reaction raw material 1 and the pressurized reaction raw material 2 to collide, mix and react to generate catalyst precursor droplets, obtaining the downward material of the suspension tower, contacting with the upward air flow in a cross-flow manner, undergoing a drying, roasting and / or activation process, and forming a catalyst powder as the iron-based catalyst for hydrogenation and liquefaction of the solid hydrocarbon feedstock; In step S4, the device for forming droplets is an atomizing device, and the atomizing device is a pressure atomizing device, a centrifugal atomizing device, a pneumatic atomizing device or an ultrasonic atomizing device; at least two of the atomizing devices are arranged opposite to each other so that the sprayed droplets converge in the same area; and the diameter of the droplets is controlled to be less than 1.2 mm.

2. The preparation method according to claim 1, wherein: In step S1, the iron salt is at least one of ferric sulfate, ferric chloride, ferric nitrate, ferrous sulfate, ferrous chloride, ferric acetate or ferrous acetate aqueous solution; The precipitant is at least one of ammonia water, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, ammonium carbonate, ammonium bicarbonate, calcium hydroxide and barium hydroxide; Using water to prepare the solution of the iron salt and the solution of the precipitant; The mass percentage concentration of the iron salt solution is 10-35%, and the mass percentage concentration of the precipitant solution is 10-35%.

3. The preparation method according to claim 1 or 2, characterized in that: In step S1, the additive is at least one of coal powder, coal char, silica gel, pumice, diatomaceous earth, montmorillonite, kaolin, clay, silica sol, alumina sol, fly ash, coal slag, activated carbon, carbon nanotubes, molecular sieves, metal organic frameworks, alumina, and oxides of the following metals and salts thereof; The metals are titanium, zirconium, cerium, zinc, manganese, nickel, molybdenum and tungsten.

4. The preparation method according to claim 1 or 2, characterized in that: Step S4 further includes the following steps of treating the dust-laden tail gas discharged from the gas outlet of the suspension forming tower: The catalyst fine powder entrained in the dust-containing tail gas is removed by an exhaust dust removal system, and the catalyst fine powder is mixed with the catalyst powder to serve as the iron-based catalyst for hydrogenation and liquefaction of the solid hydrocarbon feedstock; The dust-removed tail gas after the catalyst fine powder is removed is recycled or discharged after tail gas purification treatment.

5. An iron-based catalyst for hydrogenation and liquefaction of solid hydrocarbon feedstock prepared by the method according to any one of claims 1 to 4.

6. Use of the iron-based catalyst for hydrogenation and liquefaction of solid hydrocarbon feedstock according to claim 5 in catalyzing the hydrogenation and liquefaction of solid hydrocarbon feedstock.

7. The use according to claim 6, characterized in that: The solid hydrocarbon raw materials are coal, biomass, industrial waste and domestic waste.

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