A heavy carbon-containing raw material slurry bed hydrogenation iron-based catalyst and preparation method thereof
The iron salt solution is processed in the suspension forming tower by spray pyrolysis method to form uniform particles of iron-based catalyst powder, which solves the problems of insufficient catalyst activity and complex preparation process in the prior art, and achieves efficient catalytic performance and low cost Production.
Patent Information
- Application Number
- CN202310191346.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-03-02
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2043-03-02
AI Technical Summary
The existing iron-based catalysts are difficult to achieve ultra-fine and high dispersion during coal hydrogenation liquefaction, resulting in insufficient activity, and complex preparation process and high cost.
The iron salt solution is mixed with alkali and support by spray pyrolysis method, and the gas flow in the suspension molding tower is intercurrently contacted to form a catalyst powder, controlling the particle size distribution and phase structure, and achieving uniform particle size, texture structure and dispersion degree. sex.
The catalyst production cost is reduced, the hydrogenation conversion efficiency of carbon-containing raw materials is improved, and the catalyst powder is easily dispersed, which improves the catalytic performance.
Smart Images
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Abstract
Description
Technical Field
[0001] The invention relates to an iron-based catalyst for hydrogenation of heavy carbon-containing raw materials in a slurry bed and a preparation method thereof, and belongs to the field of energy chemical industry. Background Art
[0002] Although the performance of a catalyst is mainly determined by its chemical composition and structure, the preparation method and process of the catalyst also have an important influence on the performance of the catalyst. Sometimes catalysts with the same chemical composition may exhibit different catalytic performance due to different preparation methods or processes. In a sense, the invention and innovation of catalyst preparation technology is an important means of invention and innovation of industrial catalysts.
[0003] Heavy carbonaceous raw material slurry bed hydrogenation catalyst is mainly used for the hydrogenation conversion and upgrading process of carbonaceous heavy raw materials (such as coal, biomass, industrial and domestic waste, residue, inferior / heavy oil) with a slurry bed (or suspended bed) as a reactor. The catalysts used for coal hydrogenation liquefaction are mainly halide catalysts, transition metal catalysts, and cheap iron-based catalysts. Halides also have catalytic cracking properties on coal, but they have a strong corrosive effect on equipment. Transition metal catalysts are highly active, but relatively expensive, difficult to recycle, and costly. Iron-based catalysts are used in most coal hydrogenation liquefaction processes because of their wide raw material sources, low prices, and moderate catalytic activity. Iron-based catalysts (precursors) can come from natural minerals or artificial synthesis. Natural iron-containing ores are used as catalysts, but they are difficult to grind to a fine enough size or have non-optimal composition phase problems, so their activity is not good enough and the amount added is relatively high. Artificial synthesis can improve the performance of iron-based catalysts by increasing catalyst dispersion, surface modification, or element doping.
[0004] In order to achieve ultrafine and high dispersion, freshly synthesized (precursor or primary) iron-based catalysts are usually highly dispersed in solvents as colloids or nanoparticles, which makes it difficult to achieve desolventization and pretreatment in a simple way. The spray molding method is often used in powder processing or material preparation industries. After the spray process, powders with uniform properties (such as particle size, particle size distribution, particle morphology, and particle composition) can be obtained in one step. Therefore, it is considered to apply the spray pyrolysis method to this slurry bed catalyst molding field. Summary of the invention
[0005] The purpose of the present invention is to provide a method for preparing an iron-based catalyst for slurry bed hydrogenation of carbon-containing raw materials. The obtained catalyst powder has the characteristics of uniform particle size, texture structure and dispersion degree, is easy to achieve high dispersion in heavy carbon-containing raw materials, and improves the hydrogenation conversion efficiency of carbon-containing raw materials.
[0006] The preparation method of the slurry bed iron-based catalyst provided by the present invention comprises the following steps:
[0007] S1. Prepare a slurry according to any one of the following 1) to 4), wherein the solid content of the slurry is 5 to 60 wt.%:
[0008] 1) A solution of an iron salt or a mixture of a solution of an iron salt and a solution of an alkali;
[0009] 2) mixing the iron salt solution and the carrier or mixing the iron salt solution, the alkali solution and the carrier;
[0010] 3) mixing the solution of the iron salt and the solution of the auxiliary agent or mixing the solution of the iron salt, the solution of the alkali and the solution of the auxiliary agent;
[0011] 4) mixing a solution of an iron salt, a solution of a carrier and a solution of an auxiliary agent, or mixing a solution of an iron salt, a solution of an alkali, a solution of a carrier and a solution of an auxiliary agent;
[0012] S2, the air flow is preheated and then introduced into the suspension forming tower to form an upward air flow;
[0013] S3, sending the slurry into the suspension forming tower in the form of droplets, the droplets are suspended downward, contacted with the upward hot air flow in a cross-flow, undergo desolventization or desolventization and phase conversion process, and form catalyst powder as the slurry bed iron-based catalyst, which falls to the bottom of the suspension forming tower.
[0014] In the above-mentioned preparation method, in step S1, the solution is prepared using at least one of water, solvent oil, diesel, benzene, methanol, ethanol, cyclohexane and carbon tetrachloride;
[0015] The iron salt is at least one of FeCl3, FeCl2, Fe2(SO4)3, FeSO4, Fe(NO3)3 and Fe(OH)(CH3COO)2;
[0016] The base is at least one of ammonia, urea, sodium sulfide, ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, sodium hydroxide and potassium hydroxide;
[0017] The carrier is at least one of SiO2, Al2O3, ZnO, CaO, MnO2, ZrO2, kaolin, diatomaceous earth, activated carbon, coal powder, coke powder, silica sol and alumina sol;
[0018] The auxiliary agent is a sulfur auxiliary agent and / or a metal auxiliary agent;
[0019] The sulfur promoter is at least one of sulfur, carbon disulfide, and dimethyl disulfide;
[0020] The metal additive is one or more metal compounds containing Mo, Co, Ni, Ru, Rh, Pd, and Pt elements;
[0021] The concentration of the iron salt solution is 5 to 30%;
[0022] The concentration of the alkali solution is 5 to 30%;
[0023] The concentration of the auxiliary agent solution is 1-30%.
[0024] In the above preparation method, in step S2, the gas flow is a main gas flow or a mixed gas of the main gas flow and the auxiliary gas flow, and the volume content of the auxiliary gas flow is 0 to 20%, but not zero;
[0025] The main gas flow is at least one of nitrogen, helium, argon, oxygen, air and hydrogen;
[0026] The auxiliary gas flow is at least one of hydrogen sulfide, ammonia, carbon monoxide, carbon dioxide and water vapor;
[0027] The gas space velocity of the gas flow is 0.2 to 2.0 m / s;
[0028] A gas distributor is arranged at the bottom of the suspension forming tower, and the gas flow enters the suspension forming tower after passing through the gas distributor.
[0029] In the above preparation method, in step S2, in the suspension forming tower, the temperature of the gas inlet is 300-600°C, the temperature of the gas outlet is 180-360°C, and the operating pressure is 0.1-1 MPa.
[0030] In the above-mentioned preparation method, in step S2, 1 to 4 atomizing devices are arranged on the top or side wall of the suspension forming tower to form the slurry into the droplets;
[0031] The atomizing device is a pressure atomizing device, a centrifugal atomizing device, a pneumatic atomizing device or an ultrasonic atomizing device;
[0032] At least 90% of the droplets have a diameter of less than 1.2 mm.
[0033] In the above-mentioned preparation method, in step S3, the method further comprises the following treatment steps for the dust-containing tail gas discharged from the gas outlet of the suspension forming tower:
[0034] The catalyst fine powder entrained in the dust-containing tail gas is removed by a tail gas dust removal system, and the catalyst fine powder is mixed with catalyst powder to serve as the slurry bed iron-based catalyst.
[0035] In the above preparation method, the dust-free tail gas after removing the catalyst fine powder is recovered by solvent to obtain desolventized tail gas, and then pollutants are removed to obtain purified tail gas, which is then recycled or discharged.
[0036] The iron-based slurry bed catalyst prepared by the method of the present invention can be used in the quality improvement process of the slurry bed of carbon-containing heavy raw materials;
[0037] Preferably, the carbonaceous heavy raw materials include coal, biomass, industrial and domestic waste, residues, and low-quality / heavy oil, but are not limited thereto.
[0038] The present invention delivers the catalyst slurry into a suspension forming tower in the form of droplets. During the process of suspension and downward movement, the droplets are in cross-flow contact with the upward hot air flow, and in a suspended state, undergo desolventization or desolventization and phase transformation processes to generate catalyst powders with desired particle size distribution and composition structure. The particle size distribution of the catalyst powder is controlled by adjusting the droplet size; the phase of the catalyst powder is controlled by adjusting the temperature gradient and atmosphere in the tower. The preparation process is simple and the raw material utilization rate is high, which can effectively reduce the production cost of the catalyst. With the help of the suspension state of the forming process, an ultrafine and highly dispersed phase is formed. The obtained catalyst powder has the characteristics of uniform particle size, texture structure, and dispersion degree, and is easy to achieve high dispersion in heavy carbon-containing raw materials, thereby improving the hydrogenation conversion efficiency of carbon-containing raw materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Figure 1 This is a flow chart of the method for preparing a slurry bed hydrogenation catalyst according to the present invention, in which the symbols are as follows:
[0040] 1 material preparation unit, 2 pulping unit, 3 suspension forming tower, 4 product tank, 5 tail gas dust removal system, 6 fine powder collection tank, 7 solvent recovery system, 8 tail gas decontamination system, 9 gas heater, x heat exchanger. DETAILED DESCRIPTION
[0041] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.
[0042] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.
[0043] The preparation method of the catalyst provided by the present invention is as follows Figure 1 The process shown is carried out:
[0044] In the material preparation unit 1, the raw materials are prepared into a solution of a desired concentration and a powder of a desired particle size. In the slurry making unit 2, the desired solution and powder are mixed evenly according to a set method to obtain a slurry.
[0045] The main gas flow is entrained with the auxiliary gas flow, and after being preheated by the gas heater 9, it is passed into the suspension forming tower 3 to form an upward gas flow in the tower; after the gas flow in the tower is stable, the slurry is sent into the tower in the form of droplets through the atomizing device; the droplets are suspended downward and contacted with the upward gas flow in the tower, undergoing desolventization or desolventization and phase transformation process, to generate catalyst powder with required particle size distribution and composition structure, and fall to the bottom of the tower. The catalyst fine powder is entrained in the upward gas flow to form dusty tail gas, which is discharged from the upper part of the tower.
[0046] The catalyst powder at the bottom of the suspension forming tower 3 is collected in a product tank 4 and stored in an inert medium.
[0047] The dust-containing tail gas is cooled to the set temperature by the heat exchanger x, and then sent to the tail gas dust removal system 5 to collect the catalyst fine powder in the dust-containing tail gas and store it in the fine powder collection tank 6; the dust-removed tail gas is sent to the solvent recovery system 7 to recover the solvent; the tail gas after the solvent is removed is sent to the tail gas pollutant removal system 8 to remove pollutants to obtain purified tail gas. The purified tail gas can be sent to the gas heater 9 for recycling or evacuation.
[0048] Specifically, according to Figure 1 The process shown in the figure, the preparation method of the slurry bed catalyst provided by the present invention comprises the following steps:
[0049] (1) preparing Fe salt solution, alkaline solution, carrier and auxiliary agent solution for use;
[0050] (2) slurrying: the Fe salt solution, alkaline solution, carrier and auxiliary agent solution in step (1) are uniformly mixed into slurry according to a specific combination;
[0051] (3) The main gas flow is entrained with the auxiliary gas flow, which is preheated and then introduced into the suspension forming tower to form an upward gas flow in the tower;
[0052] (4) The slurry in step (2) is fed into a suspension forming tower in the form of droplets; the droplets are suspended downward and come into cross-flow contact with the upward hot air flow formed in step (3), undergoing a desolventizing or desolventizing and phase conversion process to generate catalyst powder with desired particle size distribution and composition structure, which falls to the bottom of the tower; the catalyst fine powder is entrained in the upward air flow to form dusty tail gas;
[0053] (5) The dust-containing tail gas obtained in step (4) is discharged and sent to a tail gas dust removal system to collect the catalyst fine powder 2 to obtain dust-free tail gas;
[0054] (6) sending the dust-free tail gas from step (5) to a solvent recovery system to recover the solvent to obtain the solvent-free tail gas;
[0055] (7) sending the desolventizing tail gas from step (6) to a pollutant removal system to obtain purified tail gas, which is then recycled or discharged;
[0056] (8) The catalyst powder 1 obtained in step (4) and the catalyst powder 2 obtained in step (5) are mixed to obtain catalyst fine powder, which is stored in an inert medium.
[0057] Preferably, the solvent used to prepare the Fe salt solution, the alkaline solution and the auxiliary agent solution in step (1) is one or more of water and / or any organic solvent that can dissolve the raw materials (such as solvent oil, diesel, benzene, methanol, ethanol, cyclohexane, carbon tetrachloride);
[0058] Preferably, the iron salt used to prepare the Fe salt solution in step (1) is one or more of any Fe-containing substances soluble in the above solvent, such as FeCl3, FeCl2, Fe2(SO4)3, FeSO4, Fe(NO3)3, Fe(OH)(CH3COO)2, etc.;
[0059] Preferably, the substance used to prepare the alkaline solution in step (1) is one or more of any substances that can release hydroxyl ions after being dissolved in the above solvent, such as ammonia, urea, sodium sulfide, ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, etc.;
[0060] Preferably, the carrier in step (1) is one or more of any carriers commonly used in the art, such as SiO2, Al2O3, ZnO, CaO, MnO2, ZrO2, kaolin, diatomaceous earth, activated carbon, coal powder, coke powder, silica sol, alumina sol, etc.;
[0061] Preferably, the auxiliary agent in step (1) is a sulfur auxiliary agent and / or a metal auxiliary agent; preferably, any related substance commonly used in the art is used; further preferably, one or more of sulfur, carbon disulfide, and dimethyl disulfide are used as the sulfur auxiliary agent, and one or more of the following metal compounds are used: Mo, Co, Ni, Ru, Rh, Pd, Pt;
[0062] Preferably, the concentration range of the Fe salt solution is 5-30 wt.%, the concentration range of the alkali solution is 5-30 wt.%, and the concentration range of the additive solution is 1-30 wt.%.
[0063] Preferably, the slurry in step (2) is slurried in the following manner:
[0064] a. Mix only the Fe salt solution and the alkaline solution into a slurry: drip one solution into another solution or drip two solutions simultaneously under stirring conditions;
[0065] b. Mixing the Fe salt solution, the alkaline solution and the carrier into a slurry: under stirring conditions, the carrier is mixed with the Fe solution or the alkaline solution, and then dripped into the other solution or dripped into the two solutions at the same time;
[0066] c. Mixing the Fe salt solution, the alkaline solution and the additive into a slurry: The Fe solution and the alkaline solution are mixed by the above-mentioned slurrying method a, and then stirring is continued, and the additive is added to mix uniformly;
[0067] d. Mixing the Fe salt solution, alkaline solution, carrier and additive into slurry: Using slurrying method b, the Fe solution, alkaline solution and carrier are mixed, and then stirring is continued, and the additive is added to mix evenly;
[0068] Preferably, the solid content of the slurry is 5 to 60 wt.%.
[0069] Preferably, in step (3), the main body of the suspension forming tower is a cylindrical body, and its main components include a slurry spray device, a gas inlet and outlet, a gas distributor, and a powder collecting device;
[0070] Preferably, the upper part of the tower has a larger diameter to reduce the tail gas velocity and the amount of fine powder entrained in the tail gas;
[0071] Further preferably, the tower bottom is a cone with a large top and a small bottom, which is conducive to the collection of powder.
[0072] Preferably, the inlet temperature of the hot main airflow of the suspension forming tower is in the range of 300-600°C, and the operating pressure of the tower body is in the range of 0.1-1MPa;
[0073] Preferably, the gas space velocity is 0.2 to 2.0 m / s;
[0074] Preferably, in step (3), the main gas flow is one or more of nitrogen, helium, argon, oxygen, air, and hydrogen;
[0075] The auxiliary gas flow is one or more combinations of hydrogen sulfide, ammonia, carbon monoxide, carbon dioxide, and water vapor;
[0076] Preferably, the main gas flow is introduced from the lower part of the suspension forming tower;
[0077] Preferably, the gas introduced into the suspension forming tower passes through a conventional or optional gas distributor (such as a porous straight tube gas distributor, a straight tube baffle gas distributor, a tangential horn gas distributor) to form a uniformly distributed upward gas flow, which contacts with the descending material in the tower, forms a temperature gradient in the tower, and is discharged from the top of the tower;
[0078] Still more preferably, auxiliary gas content = 0-20% (volume ratio);
[0079] Preferably, in step (4), the atomizing device is installed at any position on the top or side wall of the suspension forming tower, and the slurry is fed into the suspension forming tower in the form of droplets in the axial direction, radial direction or at any angle of the tower;
[0080] Furthermore, the atomizing device in step (4) adopts one or more combinations of conventional and arbitrary atomizers in the art, such as pressure type, centrifugal type, pneumatic type and ultrasonic type;
[0081] Preferably, the catalyst particle size distribution is controlled by adjusting the number of atomizing devices (1 to 4) to form a droplet size.
[0082] Further preferably, according to the properties of the material, the atomizing device is adjusted so that at least 90% of the droplets have a diameter below 1.2 mm.
[0083] Preferably, in the suspension forming tower, the descending droplets are in cross-flow contact with the ascending airflow to form a temperature gradient in the tower.
[0084] Preferably, the dust-containing exhaust gas separation device in step (5) adopts any dust separation device commonly used in the art (such as cyclone separation dust removal, bag dust removal and electrostatic precipitator); the solvent recovery device in step (6) adopts any condensation / heat exchange device commonly used in the art; the exhaust gas treatment device in step (7) adopts any exhaust gas absorption device commonly used in the art.
[0085] Preferably, the operating conditions of the tail gas separation device are as follows: temperature 90-350°C, pressure 0.1-1 MPa;
[0086] Preferably, the operating conditions of the solvent recovery device are as follows: temperature 20-120°C, pressure 0.1-1 MPa;
[0087] Preferably, the operating conditions of the tail gas treatment device are as follows: temperature 20-100°C, pressure 0.1-1MPa.
[0088] In a preferred embodiment, the inert medium in step (8) comprises one or more of nitrogen, argon, higher alkanes, and water.
[0089] In a preferred embodiment, the iron-based slurry bed catalyst is used in a slurry bed upgrading process for a carbon-containing heavy feedstock;
[0090] Preferably, the carbonaceous heavy feedstock includes coal, biomass, industrial and domestic waste, residues, low-quality / heavy oil, but is not limited thereto.
[0091] In the following examples, the hydrogenation liquefaction performance of the coal liquefaction catalyst obtained in the examples was evaluated using coal A, and the industrial analysis and elemental analysis of coal A are shown in Table 1. The reaction conditions are: pressure 1-5 MPa, temperature 400-450°C, residence time 30-240 min, catalyst loading 1%-3% (mass fraction) Fe daf .
[0092] Table 1 Raw coal properties
[0093]
[0094] In the following examples, the hydrogenation performance of the inferior oil hydrogenation catalyst obtained in the examples was evaluated using heavy oil B, and the distillation range and elemental analysis of heavy oil B are shown in Table 2. The reaction conditions are: pressure 1-5 MPa, temperature 400-450°C, residence time 30-240 min, catalyst loading 1%-10% (mass fraction) Fe daf .
[0095] Table 2 Heavy oil properties
[0096]
[0097] In the following examples, C coal tar was used to evaluate the hydrogenation performance of the inferior oil hydrogenation catalyst obtained in the examples, and the distillation range and elemental analysis of C coal tar are shown in Table 3. The reaction conditions are: pressure 1-5 MPa, temperature 400-450°C, residence time 30-240 min, and catalyst loading 1%-10% (mass fraction) Fedaf.
[0098] Table 3 Coal tar properties
[0099]
[0100] Comparative Example 1: Preparation of Catalyst CatA
[0101] Dissolve 230kg of ferric nitrate in 770kg of water to obtain an iron salt solution; dissolve 100kg of saturated ammonia water in 100kg of water to obtain an alkaline solution; dissolve 3kg of nickel nitrate in 7kg of water to obtain a metal additive solution; uniformly mix the obtained alkaline solution with 100kg of kaolin, and then dropwise add and mix with the iron salt solution at the same time, continue stirring, add the additive solution to obtain a mixed slurry with a solid content of 15%; filter, wash and dry the obtained slurry to obtain a block catalyst. Grind and mix the obtained block catalyst with solvent oil, and treat it at 280°C for 60min under a 10% CO / H2 atmosphere to obtain CatA, which is stored in a nitrogen environment for later use.
[0102] Example 1. Preparation of Catalyst Cat1
[0103] 300 kg of ferrous sulfate was dissolved in 700 kg of water to obtain an iron salt solution; 300 kg of urea was dissolved in 700 kg of water to obtain an alkaline solution; the alkaline solution was dripped into the iron salt solution to obtain a mixed slurry with a solid content of 10%; air was heated to 600°C and sent to a forming tower through a porous straight tube gas distributor at a gas velocity of 0.2 m / s, and the outlet temperature of the forming tower was maintained at 180°C; the obtained slurry was sent to a group of pressure atomizers axially arranged on the top of the forming tower, and the pressure was operated. The force is 1.0MPa, and suspended downward droplets are obtained, the droplet diameter is less than 0.9mm, the droplets are in cross-flow contact with the upward hot air, the solvent is removed, and catalyst powder A1 is obtained in the powder collection device at the bottom of the tower; the dust-containing tail gas is sent to a three-stage cyclone separation system (operating temperature 120℃) to obtain catalyst powder A2; the dust-free tail gas is sent to a condenser (operating temperature 60℃), and the condensed water and dehydrated air are recycled; the catalyst powders A1 and A2 are mixed to obtain Cat1, which is placed in water for storage for future use.
[0104] Example 2: Preparation of Catalyst Cat2
[0105] Dissolve 150kg of ferric chloride in 850kg of ethanol to obtain an iron salt solution; dissolve 150kg of ammonium carbonate in 850kg of water to obtain an alkaline solution; mix the obtained iron solution with 50kg of SiO2 is uniformly mixed and then dropped into the obtained alkaline solution to obtain a mixed slurry with a solid content of 5%; 5H2S / H2 is heated to 300°C and sent to a forming tower through a straight tube baffle gas distributor at a gas velocity of 0.5m / s, with an operating pressure of 0.3MPa and an outlet temperature of 320°C; the obtained slurry is sent to two groups of centrifugal atomizers radially arranged on the side walls of the forming tower to obtain suspended descending droplets with a diameter of less than 0.3mm, and the droplets are in cross-flow contact with the ascending hot gas to remove the solvent and undergo a sulfide reaction, and catalyst powder B1 is obtained in a powder collection device at the bottom of the tower; the dust-containing tail gas is sent to a bag dust removal system (operating temperature 90°C) to obtain catalyst powder B2; the dust-free tail gas is sent to a condenser (operating temperature 20°C) to condense ethanol for recycling; the desolventized gas is sent to an alkali solution absorption tower (operating temperature 20°C), and the purified tail gas is recycled; the catalyst powders B1 and B2 are mixed to obtain Cat2, which is placed in Fischer-Tropsch diesel for storage and standby.
[0106] Example 3: Preparation of Catalyst Cat3
[0107] Dissolve 50kg of ferric acetate in 950kg of ethanol to obtain an iron salt solution; dissolve 50kg of sodium hydroxide in 950kg of ethanol to obtain an alkaline solution; dissolve 10kg of sulfur in 90kg of solvent oil to obtain a sulfur auxiliary agent solution; drop the obtained iron salt solution and alkaline solution and mix them simultaneously, continue stirring, add the auxiliary agent solution to obtain a mixed slurry with a solid content of 2%; heat 20% CO / Ar to 450℃, and feed it into a forming tower through a tangential horn gas distributor at a gas speed of 2.0m / s, with an operating pressure of 0.5MPa and an outlet temperature of 210℃; feed the obtained slurry into a forming tower with an angle of 4 between the top of the tower and the axial direction. Four groups of pneumatic atomizers are set at 5° to obtain suspended descending droplets with a diameter of less than 1 mm. The droplets are in cross-flow contact with the ascending hot gas, the solvent is removed and a carbonization reaction occurs, and the catalyst powder C1 is obtained in the powder collection device at the bottom of the tower; the dust-containing tail gas is sent to the electrostatic precipitator system (operating temperature 350°C) to obtain catalyst powder C2; the dust-free tail gas is sent to the heat exchanger (operating temperature 120°C) to condense the solvent for recycling; the desolvated gas is sent to the alkali solution absorption tower (operating temperature 100°C) and recycled after purification; the catalyst powders C1 and C2 are mixed to obtain Cat3, which is stored under a nitrogen atmosphere for standby use.
[0108] Example 4. Preparation of Catalyst Cat4
[0109] Dissolve 230kg of ferric nitrate in 770kg of water to obtain an iron salt solution; dissolve 100kg of saturated ammonia water in 100kg of water to obtain an alkaline solution; dissolve 3kg of nickel nitrate in 7kg of water to obtain a metal additive solution; uniformly mix the obtained alkaline solution with 100kg of kaolin, and then dropwise add and mix with the iron salt solution at the same time, continue stirring, add the additive solution to obtain a mixed slurry with a solid content of 15%; heat 10% CO / H2 to 450℃, and send it into the forming tower through a porous straight tube gas distributor at a gas velocity of 1.0m / s, with an operating pressure of 1.0MPa and an outlet temperature of 280℃; send the obtained slurry into the axially arranged gas distributor at the top of the forming tower. Two groups of ultrasonic atomizers are placed to obtain suspended descending droplets with a diameter of less than 0.1 mm. The droplets are in cross-flow contact with the ascending hot gas to remove the solvent and undergo a reduction reaction, and catalyst powder D1 is obtained in the powder collecting device at the bottom of the tower; the dust-containing tail gas is sent to a primary cyclone separation system and a bag dust removal system (operating temperature 350°C) in sequence to obtain catalyst powder D2; the dust-removed tail gas is sent to a condenser (operating temperature 20°C) to condense the solvent for recycling; the solvent-removed gas is sent to an alkali solution absorption tower (operating temperature 20°C) for recycling after purification; the catalyst powders D1 and D2 are mixed to obtain Cat4, which is placed in a nitrogen and water environment for storage for standby use.
[0110] Example 5. Preparation of Catalyst Cat5
[0111] Dissolve 200kg of ferrous sulfate in 800kg of water to obtain an iron salt solution; dissolve 150kg of sodium sulfide in 850kg of water to obtain an alkaline solution; dissolve 1kg of chloroplatinic acid in 99kg of water to obtain a metal additive solution; uniformly mix the obtained iron salt solution with 800kg of coal powder, and then drop and mix with the alkaline solution at the same time, continue stirring, add the additive solution to obtain a mixed slurry with a solid content of 5%; heat 8% H2 / N2 to 550℃, and feed it into the forming tower through a porous straight tube gas distributor at a gas speed of 1.0m / s; feed the obtained slurry into the axially arranged gas distributor at the top of the forming tower Three groups of pressure atomizers are installed to obtain suspended descending droplets, which are in cross-flow contact with the ascending hot gas. The operating pressure is 0.9 MPa and the outlet temperature is 450°C. The solvent is removed and a reduction reaction occurs. Catalyst powder E1 is obtained in the powder collecting device at the bottom of the tower; the dust-containing tail gas is sent to the secondary cyclone separation system and the electrostatic precipitator system (operating temperature 120°C) in sequence to obtain catalyst powder E2; the dust-free tail gas is sent to the condenser (operating temperature 20°C), and the condensed water and tail gas are recycled; the catalyst powders E1 and E2 are mixed to obtain Cat5, which is placed in an argon environment for storage for future use.
[0112] Example 6: Preparation of Catalyst Cat6
[0113] 230 kg of ferric nitrate was dissolved in 770 kg of water to obtain an iron salt solution; 3 kg of nickel nitrate was dissolved in 7 kg of water to obtain a metal additive solution; the obtained iron salt solution was uniformly mixed with 100 kg of silica sol (25 wt%), and the stirring was continued, and the additive solution was added to obtain a mixed slurry with a solid content of 20%; the air was heated to 500°C and sent to a forming tower through a porous straight tube gas distributor at a gas velocity of 1.5 m / s, with an operating pressure of 0.1 MPa and an outlet temperature of 200°C; the obtained slurry was sent to two groups of ultrasonic atomizers axially arranged at the top of the forming tower to obtain a straight The suspended downward droplets with a diameter of less than 0.1mm are in cross-flow contact with the upward hot gas to remove the solvent, and the catalyst powder D1 is obtained in the powder collection device at the bottom of the tower; the dust-containing tail gas is sent to the primary cyclone separation system and the bag dust removal system (operating temperature 180℃) in sequence to obtain catalyst powder D2; the dust-removed tail gas is sent to the condenser (operating temperature 20℃) to condense the solvent for recycling; the desolventized gas is sent to the alkali solution absorption tower (operating temperature 20℃) for recycling after purification; the catalyst powders D1 and D2 are mixed to obtain Cat6, which is placed in a nitrogen environment for storage for future use.
[0114] Table 4 Conditions and results of hydrogenation of carbon-containing heavy raw materials using the catalysts obtained in Examples 1-5
[0115]
[0116] The comparison of the performance of the catalysts for hydrogenation and upgrading of carbon-containing raw materials shown in the above table shows that the present invention has the characteristics of simple preparation process and high raw material utilization rate, which can effectively reduce the production cost of the catalyst. With the help of the suspension state in the molding process, an ultrafine highly dispersed phase is formed. The catalyst powder obtained by the present invention has the characteristics of uniform particle size, texture structure, and dispersion degree, and is easy to achieve high dispersion in heavy carbon-containing raw materials, thereby improving the hydrogenation conversion efficiency of carbon-containing raw materials.
Claims
1. A method for preparing an iron-based catalyst for slurry bed hydrogenation of heavy carbonaceous raw materials, characterized in that: A preparation device for a heavy carbon-containing raw material slurry bed hydrogenation iron-based catalyst is used, the preparation device comprising a material preparation unit (1), a slurry making unit (2), a suspension forming tower (3), a product tank (4), an exhaust gas dust removal system (5), a fine powder collection tank (6), a solvent recovery system (7), an exhaust gas decontamination system (8), a gas heater (9), and a heat exchanger. The suspension forming tower (3) is provided with a preheating gas inlet at the bottom, a slurry droplet inlet and a dust-containing tail gas outlet at the top, and a catalyst powder outlet at the bottom; The material preparation unit (1) is provided with a liquid raw material inlet and a material outlet, the material outlet of the material preparation unit (1) is connected to the material inlet of the pulping unit (2); the material outlet of the pulping unit (2) is connected to the slurry droplet inlet of the suspension forming tower (3) through a pipeline; The gas heater (9) is provided with an air inlet and an air outlet, the air inlet of the gas heater (9) is used to connect fresh air, and the air outlet of the gas heater (9) is connected to the preheating gas inlet of the suspension forming tower (3); The tail gas dust removal system (5) is provided with a dust-containing tail gas inlet, a solvent outlet and a fine powder outlet, and the product tank (4) is provided with a main inlet, a secondary inlet and a mixed outlet. The catalyst powder outlet of the suspension forming tower (3) is connected to the main inlet of the product tank (4); the dust-containing tail gas outlet of the suspension forming tower (3) is connected to the dust-containing tail gas inlet of the tail gas dust removal system (5) through a pipeline; the fine powder outlet of the tail gas dust removal system (5) is connected to the inlet of the fine powder collection tank (6), and the outlet of the fine powder collection tank (6) is connected to the secondary inlet of the product tank (4); the mixed outlet of the product tank (4) is used to output the formed catalyst; The solvent recovery system (7) is provided with an inlet, an outlet and a solvent recovery outlet at the bottom, the solvent recovery outlet is used to output the recovered solvent, the tail gas decontamination system (8) is provided with an inlet, an outlet and a wastewater outlet at the bottom, the wastewater outlet is used to output wastewater, the solvent outlet of the tail gas dust removal system (5) is connected to the inlet of the solvent recovery system (7), the outlet of the solvent recovery system (7) is connected to the inlet of the tail gas decontamination system (8), and the outlet of the tail gas decontamination system (8) is connected to the air inlet of the gas heater (9), thereby, the dust-containing tail gas outlet of the suspension forming tower (3) passes through the tail gas decontamination system (5), the solvent recovery system (7), the tail gas decontamination system (8), the gas heater (9) in sequence, and finally returns to the suspension forming tower (3), forming a circulation loop; Wherein, an atomizing device is arranged on the pipeline connecting the discharge port of the pulping unit (2) and the slurry droplet inlet of the suspension forming tower (3); A heat exchanger is provided on the pipeline connecting the dust-containing tail gas outlet of the suspension forming tower (3) and the dust-containing tail gas inlet of the tail gas dust removal system (5); The preparation method comprises the following steps: Step A: The required solution and powder are mixed uniformly in a set manner by the slurry making unit (2) to prepare a slurry, including preparing the slurry in any of the following ways 1) to 4): 1) A solution of an iron salt or a mixture of a solution of an iron salt and a solution of an alkali; 2) mixing a solution of an iron salt and a carrier or mixing a solution of an iron salt, a solution of an alkali and a carrier; 3) mixing the solution of the iron salt and the solution of the auxiliary agent or mixing the solution of the iron salt, the solution of the alkali and the solution of the auxiliary agent; 4) mixing a solution of an iron salt, a solution of a carrier and a solution of an auxiliary agent, or mixing a solution of an iron salt, a solution of an alkali, a solution of a carrier and a solution of an auxiliary agent; The solution is prepared by using at least one of water, solvent oil, diesel, benzene, methanol, ethanol, cyclohexane and carbon tetrachloride; The concentration of the iron salt solution is 5-30%, and the iron salt is at least one of FeCl3, FeCl2, Fe2(SO4)3, FeSO4, Fe(NO3)3 and Fe(OH)(CH3COO)2; The concentration of the alkali solution is 5-30%, and the alkali is at least one of ammonia, urea, sodium sulfide, ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, sodium hydroxide and potassium hydroxide; The carrier is at least one of SiO2, Al2O3, ZnO, CaO, MnO2, ZrO2, kaolin, diatomaceous earth, activated carbon, coal powder, coke powder, silica sol and alumina sol; The concentration of the auxiliary agent solution is 1-30% and the auxiliary agent is a sulfur auxiliary agent and / or a metal auxiliary agent, wherein the sulfur auxiliary agent is at least one of sulfur, carbon disulfide, and dimethyl disulfide, and the metal auxiliary agent is one or more of metal compounds containing Mo, Co, Ni, Ru, Rh, Pd, and Pt elements; step B: the air flow gas is preheated and introduced into a suspension forming tower (3) to form an upward air flow; the slurry is sent into the suspension forming tower (3) in the form of droplets and the droplets are suspended downward; the slurry in the form of droplets is in cross-flow contact with the upward air flow to generate a catalyst powder with a desired particle size distribution and composition structure as a slurry bed iron-based catalyst, comprising the following specific steps: Step B1: fresh gas is used as the main gas flow gas, and the main gas flow gas is at least one of nitrogen, helium, argon, oxygen, air, and hydrogen; the purified tail gas flowing out of the outlet of the tail gas decontamination system (8) is used as the auxiliary gas flow gas, and the auxiliary gas flow gas is at least one of hydrogen sulfide, ammonia, carbon monoxide, carbon dioxide, and water vapor, and the volume content of the auxiliary gas flow gas is 0 to 20%, but not zero; The main gas flow and the auxiliary gas flow are introduced from the gas inlet of the gas heater (9) to form a mixed gas flow of the main gas flow and the auxiliary gas flow, wherein the gas space velocity of the mixed gas flow is 0.2 to 2.0 m / s. After the mixed gas flow is preheated by the gas heater (9), it is introduced into the suspension forming tower (3) through the preheating gas inlet, and an upward gas flow is formed in the suspension forming tower (3); Step B2: After the airflow in the tower is stabilized, the slurry is passed through an atomizing device and sent into the suspension forming tower (3) in the form of droplets through the slurry droplet inlet, wherein at least 90% of the droplets have a diameter of less than 1.2 mm. The slurry in the form of droplets is suspended downward and contacts the upward airflow in the suspension forming tower (3) in a cross-flow manner, undergoes a desolventizing or desolventizing and phase transformation process, and generates catalyst powder with a desired particle size distribution and composition structure as the slurry bed iron-based catalyst, which falls to the bottom of the suspension forming tower (3); at the same time, the catalyst fine powder is entrained in the upward airflow to form dust-containing tail gas, which is discharged from the dust-containing tail gas outlet of the suspension forming tower (3); Wherein, in the suspension forming tower (3), the temperature of the gas inlet is 300-600°C, the temperature of the gas outlet is 180-360°C, and the operating pressure is 0.1-1 MPa; Step C: The catalyst powder and the dust-containing tail gas discharged from the bottom of the suspension forming tower (3) flow out from the catalyst powder outlet and the dust-containing tail gas outlet of the suspension forming tower (3) respectively and are separated into two paths, wherein the catalyst powder that falls on the bottom of the suspension forming tower (3) is collected in the product tank (4) and stored in an inert medium; the dust-containing tail gas discharged from the other path is cooled to a set temperature by a heat exchanger and then sent to a tail gas dust removal system (5); the catalyst fine powder in the dust-containing tail gas is collected by the tail gas dust removal system (5), and the catalyst fine powder is stored in a fine powder collection tank (6), and finally flows into the product tank (4), and the catalyst fine powder is mixed with the catalyst powder to form a slurry bed iron-based catalyst; the rest The dust-containing tail gas is dedusted by the tail gas dedusting system (5) to form dust-free tail gas, which is then sent to the solvent recovery system (7). The solvent is recovered by the solvent recovery system (7) to obtain solvent and desolventized tail gas, wherein the solvent flows out from the solvent recovery outlet of the solvent recovery system (7) and is recovered, and the desolventized tail gas flows out from the outlet of the solvent recovery system (7) and is sent to the tail gas pollutant removal system (8) to remove pollutants to obtain purified tail gas; the purified tail gas is directly discharged or recycled as auxiliary gas and sent to the air inlet of the gas heater (9) to be mixed with fresh gas as the main gas flow to form a mixed gas flow of the main gas flow and the auxiliary gas flow, and then enters the step B1 to continue the cycle.
2. The preparation method according to claim 1, characterized in that: A gas distributor is arranged at the bottom of the suspension forming tower, and the gas flow enters the suspension forming tower after passing through the gas distributor.
3. The preparation method according to any one of claims 1-2, characterized in that: In step B, 1 to 4 atomizing devices are arranged on the top or side wall of the suspension forming tower (3) to form the slurry into droplets; The atomizing device is a pressure atomizing device, a centrifugal atomizing device, a pneumatic atomizing device or an ultrasonic atomizing device.
4. A slurry bed iron-based catalyst prepared by the method according to any one of claims 1 to 3.
5. Use of the slurry bed iron-based catalyst according to claim 4 in catalyzing the hydrogenation conversion and quality improvement of carbon-containing heavy raw materials.
6. The use according to claim 5, characterized in that: The carbon-containing heavy raw materials include biomass, industrial waste, domestic waste and heavy oil.