Catalyst and preparation method thereof
By developing a catalyst composed of industrial waste slag, natural ore and specific oxides, the problem of difficult tar in high-temperature waste gas is solved, and efficient cracking and transformation of waste gas is achieved, cost and environmental pollution is reduced, and it has excellent economic benefits and green prospects.
Patent Information
- Application Number
- CN202510318628.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-18
- Publication Date
- 2025-05-27
AI Technical Summary
The prior art is difficult to effectively utilize tar in high-temperature waste gas, resulting in equipment corrosion, blockage and environmental pollution, and is costly and has no green prospects.
A catalyst is developed to prepare a catalyst suitable for the cracking and conversion of waste gas by combining industrial waste slag and natural ore as main active components, combining oxides of Group IIA elements, Group VIII elements and lanthanide elements, as well as γ-Al2O3, TiO2, SiO2, ZrO2 and molecular sieve as capacity expanders and binders.
The catalyst has good stability, renewability and resistance to carbon deposits, which can effectively promote the cracking conversion of high-temperature waste gas, reduce costs, and reduce environmental pollution. It has excellent economic benefits and green prospects.
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Figure BDA0005316747800000141 
Figure BDA0005316747800000151
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of catalysts for cracking conversion reactions, and particularly to a catalyst for the cracking conversion reaction of raw coal gas and a preparation method thereof. Background Art
[0002] Raw coal gas is a dusty gas produced by the dry distillation decomposition of coal during the coking process. Its main components include gas components such as carbon monoxide, hydrogen, methane, nitrogen, carbon dioxide, and water vapor, and also contain various impurities such as tar vapor, crude benzene, ammonia, and cyanide. Among them, the presence of tar will cause certain corrosion and blockage of equipment and pipelines. Currently, in industrial applications, the method of ammonia water quenching is used to clean the pipeline to relieve the harm of tar. However, this method will produce a large amount of phenol-containing wastewater, pollute the environment, increase the cost exponentially, and a large amount of high-temperature sensible heat is wasted during the process, resulting in a low economic value of current industrial applications and no green prospect.
[0003] Directly cracking and converting high-temperature raw coal gas into low-carbon hydrocarbons and small-molecule substances under the action of a catalyst is a low-cost and extremely green method. More specifically, it is to directly crack and convert the tar in raw coal gas into low-carbon hydrocarbons and small-molecule substances through steam reforming, partial oxidation, and catalytic cracking. However, raw coal gas is in a high-temperature environment, which requires a relatively high applicable temperature range for the catalyst. At the same time, introducing H 2 O and O 2 will promote the simultaneous occurrence of multiple competitive reactions such as the catalytic cracking, steam reforming, and partial oxidation of hydrocarbons and the oxidation of carbon deposition, and is accompanied by many equilibrium reactions. Therefore, it is necessary to establish an equilibrium among multiple reaction paths with the help of a catalyst to effectively control the selectivity of reaction products. However, in the current research fields of tar cracking, tar hydrocracking, and tar steam reforming, very few catalysts can be applied to the cracking conversion process proposed by the present invention. Therefore, it is extremely important to develop a catalyst specifically for the cracking conversion of tar in high-temperature raw coal gas. Summary of the Invention
[0004] In view of this, the present invention aims to propose a catalyst that can be used for the cracking conversion reaction of raw coal gas.
[0005] To achieve the above object, the technical solution of the present invention is realized as follows:
[0006] A catalyst for the cracking conversion reaction of raw coal gas, the components of the catalyst include a main active component, a co-catalyst component, an expander, and a binder;
[0007] The main active component includes industrial waste residue and natural ore;
[0008] The cocatalytic component is selected from any one or a mixture of several of the oxides of Group IIA elements, the oxides of Group VIII elements, and the oxides of lanthanide elements;
[0009] The swelling agent is selected from any one or a mixture of several of γ-Al 2 O 3 , TiO 2 , SiO 2 , ZrO 2 , and molecular sieves;
[0010] The binder is selected from any one or a mixture of several of citric acid, sodium silicate, silica sol, methyl cellulose, sesbania powder, silicone oil, chitosan, and kaolin.
[0011] Furthermore, the mass fractions of the components in the catalyst are as follows: the main active component is 50.0 - 70.0%, the cocatalytic component is 1.0 - 10.0%, the swelling agent is 10.0 - 15.0%, and the binder is 5.0 - 10.0%.
[0012] Furthermore, the industrial waste residue is selected from any one or a mixture of two of pyrite oxidation roasting slag and steel slag; and / or,
[0013] The natural ore is selected from any one or a mixture of several of dolomite ash, olivine, and zeolite; and / or,
[0014] The oxide of Group IIA element is selected from any one or a mixture of two of Sr oxide and Ba oxide; and / or,
[0015] The oxide of Group VIII element is selected from any one or a mixture of several of Co oxide, Rh oxide, Pt oxide, and Pd oxide; and / or,
[0016] The oxide of lanthanide element is selected from any one or a mixture of two of La oxide and Ce oxide; and / or,
[0017] The molecular sieve is selected from any one or a mixture of several of 3A molecular sieve, 4A molecular sieve, and 5A molecular sieve.
[0018] Furthermore, the mass content of iron oxide in the pyrite oxidation roasting slag and the steel slag is 40.0% - 90.0%; and / or,
[0019] The total mass content of CaO and MgO in the dolomite ash is 90.0 - 99.0%; and / or,
[0020] The Sr oxide is SrO; and / or,
[0021] The cobalt oxide used is Co 3 O 4 ; and / or,
[0022] The lanthanum oxide used is La 2 O 3 ; and / or,
[0023] The cerium oxide used is CeO 2 .
[0024] The catalyst of the present invention uses industrial waste residue and natural ore as the main active components, belonging to the secondary utilization of industrial by-products, and having excellent economic benefits and green prospects. Among them, the Ca 2+ and Mg 2+ contained in the natural ore of the main active components improve the performance of the catalyst against coking and sintering. The Fe 2+ and Fe 3+ contained in the industrial waste residue further improve the sintering situation of the catalyst. At the same time, the introduction of Fe can also relieve the carbon deposition of the catalyst. In addition, the addition of the promoter component can significantly improve the activity of the catalyst, enhance the anti-poisoning effect of the catalyst, and improve the tolerance of the catalyst to toxic compounds such as chlorides, cyanides, and sulfides in the waste gas components. Therefore, the catalyst provided by the present invention has good stability, renewable ability, and anti-carbon deposition ability.
[0025] At the same time, the present invention also proposes a preparation method of the above catalyst, and the preparation method includes:
[0026] Clean, dry, and grind the main active components to obtain the original powder;
[0027] Mix the original powder with the swelling agent, and mix the binder and deionized water into a solution or a solid-liquid mixture;
[0028] Add the solution or the solid-liquid mixture to the mixture of the original powder and the swelling agent, and stir to obtain a viscous mixture;
[0029] Press the viscous mixture into a mold and dry it to form solid particles;
[0030] Dissolve the promoter component with deionized water to obtain an additive solution;
[0031] Add the additive solution to the solid particles, and then impregnate, dry, and calcine them in sequence to obtain the catalyst.
[0032] Further, the step of cleaning, drying, and grinding the main active components to obtain the original powder includes:
[0033] Wash the industrial waste residue and the natural ore separately in deionized water and dry them for a first preset time in an environment at a first preset temperature;
[0034] Put the dried industrial waste residue and the natural ore into a ball mill respectively and grind them for a second preset time at a preset rotational speed to obtain an industrial waste residue powder and a natural ore powder;
[0035] Mix the industrial waste residue powder and the natural ore powder according to a preset ratio to prepare the original powder.
[0036] Further, the preset ratio is 1:0.2 - 1.
[0037] Further, mixing the binder with deionized water into a solution or a solid-liquid mixture includes:
[0038] Weigh deionized water according to a preset ratio based on the mass of the mixture of the original powder and the swelling agent;
[0039] Mix the binder with the weighed deionized water into the solution or the solid-liquid mixture.
[0040] Further, the drying of the viscous mixture after being pressed into a shape includes the following drying processes carried out in sequence:
[0041] Dry at room temperature for a third preset time;
[0042] Dry at a second preset temperature until there is no moisture on the surface;
[0043] Roast at a third preset temperature for a fourth preset time in an inert environment.
[0044] Further, after adding the auxiliary agent solution to the solid particles, the impregnation, the drying, and the roasting carried out in sequence are respectively:
[0045] The impregnation includes impregnating the solid particles added with the auxiliary agent solution at room temperature;
[0046] The drying includes heating the solid particles that have completed impregnation to a fourth preset temperature until there is no moisture residue;
[0047] The roasting includes roasting at a fifth preset temperature for a fifth preset time in an inert gas atmosphere.
[0048] The preparation method of the catalyst of the present invention has a simple process and a short preparation process. The preparation of the catalyst is completed by means of drying, roasting, and impregnation, avoiding the complex volume calculation and adjustment in the traditional impregnation process. Specific Embodiments
[0049] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.
[0050] If no specific conditions are specified in the present invention, conventional conditions or conditions recommended by the manufacturer of the equipment used may be used. If the manufacturer of the reagents or instruments used is not specified, conventional products purchased from the market may be used. If no specific conditions are specified for the technical means or process methods involved, they shall be carried out according to existing methods and procedures in the relevant field.
[0051] This embodiment relates to a catalyst, which is used for cracking conversion reaction of raw coal gas.
[0052] In terms of overall design, the components of the catalyst of this embodiment include a main active component, a co-catalyst component, a capacity expander and a binder, wherein:
[0053] The main active components include industrial waste residues and natural ores;
[0054] The catalyst promoter component is selected from any one or a mixture of oxides of Group IIA elements, oxides of Group VIII elements and oxides of lanthanide elements;
[0055] The expander is selected from γ-Al 2 O 3 、TiO 2 、SiO 2 、ZrO 2 and any one or a mixture of several of molecular sieves;
[0056] The binder is selected from any one or a mixture of citric acid, sodium silicate, silica sol, methyl cellulose, sesbania powder, silicone oil, chitosan and kaolin.
[0057] The catalyst of this embodiment is composed of the above-mentioned components, with the main active component as the basis. The industrial waste slag in the main active component can improve the sintering condition of the catalyst. At the same time, the natural ore in the main active component can improve the anti-coking and anti-sintering properties of the catalyst. The addition of the co-catalyst component can significantly improve the activity, redox properties and anti-poisoning properties of the catalyst. The above-mentioned components act simultaneously, so that the catalyst of this embodiment has good catalytic activity in a high-temperature environment, and can efficiently promote the cracking of high-temperature raw coal gas into low-carbon hydrocarbons or small molecular substances.
[0058] It should be noted that, based on the composition of the overall components as above, further, in the specific implementation, the mass fraction composition of the components of the catalyst of this embodiment can be, for example, 50.0-70.0% of the main active component, 1.0-10.0% of the co-catalyst component, 10.0-15.0% of the expander, and 5.0-10.0% of the adhesive.
[0059] It should be noted that the industrial waste residue as the main active component in the catalyst of this embodiment, preferably, for example, can be any one or a mixture of two of pyrite oxidation roasting slag and steel slag. Among them, for the selection of pyrite oxidation roasting slag and steel slag, further preferably, for example, it can be pyrite oxidation roasting slag and steel slag with the mass content of iron oxide being 40.0% - 90.0%.
[0060] Similarly, the natural ore as the main active component, preferably, for example, can be any one or a mixture of several of dolomite ash, olivine and zeolite. Among them, for the selection of dolomite ash, further preferably, for example, it can be dolomite ash with the total mass content of CaO and MgO being 90.0 - 99.0%.
[0061] The Fe contained in the above-mentioned pyrite oxidation roasting slag 2+ and Fe 3+ further improves the sintering situation of the catalyst. At the same time, the introduction of Fe also alleviates the drawback of catalyst carbon deposition. In addition, the Ca 2+ and Mg 2+ contained in dolomite ash also improve the anti-coking performance and anti-sintering performance of the catalyst.
[0062] It should also be noted that the co-catalytic component of the catalyst in this embodiment, preferably, for example, can be any one or a mixture of several of Sr oxide, Ba oxide, Co oxide, Rh oxide, Pt oxide, Pd oxide, La oxide and Ce oxide.
[0063] Based on the introduction of the above element oxides, Sr belongs to alkaline earth elements, which can significantly enhance the catalyst activity, strengthen the anti-poisoning effect of the catalyst, and improve the tolerance of the catalyst to toxic compounds such as chlorides, cyanides and sulfides in the waste gas components of raw coal gas. At the same time, the doping of Sr helps the desorption of lattice oxygen [O], thus eliminating carbon deposition and promoting the redox mechanism of the catalyst; Co, as an oxygen-carrying metal element, the lattice oxygen provided by its oxide ranks first among many oxygen-carrying metal elements such as Ni, Fe and Cu, which can effectively enhance the carbon deposition resistance of the catalyst, and has a large thermodynamic driving force and a fast redox rate when reacting with hydrocarbon fuels, and can effectively promote the activity, regenerability and stability of the catalyst; La and Ce, as rare earth elements, have unique electronic structures and chemical properties, which can significantly improve the activity of the tar cracking reaction. In addition, the addition of La and Ce can also promote the dispersion of the active component. The synergistic effect with oxygen carriers such as Fe and Co not only further enhances the active component, but also increases the number of times the catalyst can be recycled. And the oxides of La and Ce can also react with the carbon substances on the catalyst surface at high temperatures, thus inhibiting the formation of carbon deposition.
[0064] In addition, the molecular sieve used as the swelling agent is preferably, for example, any one or a mixture of several of 3A molecular sieve, 4A molecular sieve, and 5A molecular sieve.
[0065] In summary, whether it is a single promoter metal element or the synergistic effect of multiple promoter elements, it has a significant promoting effect on the activity, redox property, and anti-poisoning property of the catalyst.
[0066] In this embodiment, for the above-mentioned Sr oxide, more preferably, for example, it can be SrO.
[0067] For the above-mentioned Co oxide, more preferably, for example, it can be Co 3 O 4 .
[0068] For the above-mentioned La oxide, more preferably, for example, it can be La 2 O 3 .
[0069] For the above-mentioned Ce oxide, more preferably, for example, it can be CeO 2 .
[0070] It should be noted that when preparing the catalyst of this embodiment, a precursor of the co-catalytic component needs to be added to generate the co-catalytic component. The precursor of the co-catalytic component is preferably, for example, a mixture of one or several of strontium nitrate, cobalt nitrate, lanthanum nitrate, and cerium nitrate.
[0071] Based on the above introduction, the catalyst of this embodiment uses industrial waste residue and natural ore as the main active components, which belongs to the secondary utilization of industrial by-products and has excellent economic benefits and a green prospect. The Ca 2+ and Mg 2+ contained in the natural ore of the main active component improve the anti-coking and sintering performance of the catalyst. The Fe 2+ and Fe 3+ contained in the industrial waste residue further improve the sintering situation of the catalyst. At the same time, the introduction of Fe can also relieve the carbon deposition of the catalyst. In addition, the addition of the co-catalytic component can significantly improve the activity of the catalyst, enhance the anti-poisoning effect of the catalyst, and improve the tolerance of the catalyst to toxic compounds such as chlorides, cyanides, and sulfides in the raw coal gas components. Therefore, the catalyst provided by the present invention has good stability, regenerability, and anti-carbon deposition ability.
[0072] In this embodiment, based on the above introduction of the catalyst, in specific implementation, an exemplary preparation method of the above-mentioned catalyst includes the following steps:
[0073] S1. Clean, dry, and grind the main active components to obtain the original powder;
[0074] S2. Mix the raw powder with the swelling agent, mix the binder with deionized water to form a solution or a solid-liquid mixture, and add the above solution or the solid-liquid mixture to the mixture of the raw powder and the swelling agent, and stir to obtain a viscous mixture;
[0075] S3. Press the viscous mixture into a shape and then dry it to form solid particles;
[0076] S4. Dissolve the co-catalytic component with deionized water to obtain an auxiliary agent solution;
[0077] S5. Add the auxiliary agent solution to the solid particles, and then impregnate, dry, and calcine in sequence to obtain the catalyst.
[0078] Specifically, in the above step S1, the main active component is washed, dried, and then ground to obtain the raw powder. As a preferred implementation form, for example, the industrial waste residue and natural ore can be separately placed in deionized water for washing, dried in a first preset temperature environment for a first preset time, and the dried industrial waste residue and natural ore are separately placed in a ball mill and ground at a preset rotation speed for a second preset time to obtain the industrial waste residue powder and natural ore powder. Then, the industrial waste residue powder and natural ore powder are mixed according to a preset ratio to obtain the raw powder.
[0079] Among them, the preset ratio, preferably, for example, can be 1:0.2 - 1.
[0080] In the above step S2, the binder is mixed with deionized water to form a solution or a solid-liquid mixture. As a preferred implementation form, for example, deionized water can be weighed according to the mass of the mixture of the raw powder and the swelling agent, and the binder is mixed with the weighed deionized water to form the solution or the solid-liquid mixture.
[0081] In the above step S3, the drying process after pressing the viscous mixture into a shape. As a preferred implementation form, for example, it can be dried at room temperature for a third preset time, dried at a second preset temperature until there is no moisture on the surface, and then calcined at a third preset temperature for a fourth preset time in an inert environment.
[0082] In the above step S5, the auxiliary agent solution is added to the solid particles, and then impregnated, dried, and calcined in sequence. For the impregnation process, as a preferred implementation form, for example, the solid particles added with the auxiliary agent solution are impregnated at normal temperature;
[0083] For the drying process, as a preferred implementation form, for example, the solid particles after impregnation are heated to a fourth preset temperature until there is no residual moisture;
[0084] For the roasting process, as a preferred implementation form, for example, it can be roasted in an inert gas atmosphere at a fifth preset temperature for a fifth preset time.
[0085] The preparation method of the catalyst in this embodiment has a simple technological process and a short preparation process. The preparation of the catalyst is completed by drying, roasting and impregnation, avoiding the complex volume calculation and adjustment in the traditional impregnation process.
[0086] Based on the above introduction, for the catalyst and its preparation method of the present invention, further, in specific implementation, the following preparation examples can be referred to.
[0087] Example 1
[0088] For ease of description, the catalyst prepared in this Example 1 can be called LHZH-1 for example, and its specific preparation steps are as follows:
[0089] S1. Wash the pyrite cinder and dolomite ash with deionized water to remove impurities, and then put them into an oven and dry for 12 h in an environment of 80 °C. Place the dried pyrite cinder and dolomite ash in a ball mill respectively, set the rotation speed of the ball mill to 200 revolutions per minute, grind them into powders and reserve.
[0090] S2. Weigh 54.162 g of pyrite cinder powder, 10.822 g of dolomite ash powder, 14.983 g of porous molecular sieve powder and 10.012 g of kaolin powder, mix them evenly, add 40.00 ml of deionized water and stir to form a viscous mixture.
[0091] S3. Transfer the above mixture to a mold, use a jack for tablet pressing and curing, and the weighing / force measuring controller shows 972 kg to make a sheet-like solid. Dry the above solid at room temperature for 8 h, then transfer it to an oven and dry for 10 h in an environment of 70 °C. After drying, transfer the sample to a muffle furnace and roast at 900 °C for 4 h. After roasting, crush the sample into 20 - 40 mesh particles. Take a small amount of particles to test the water absorption, and the result is 0.409 ml / g, and then dry the particles and reserve.
[0092] S4. Weigh 5.588 g of Co(NO 3 ) 2 ·6H 2 O, 4.210 g of La(NO 3 ) 3 ·6H 2 O, 4.190 g of Ce(NO 3 ) 3 ·6H 2 O, 4.350 g of Sr(NO 3 ) 2 ·4H2 O, 36.80 ml of deionized water was added according to the water absorption of the particles to prepare a solution.
[0093] S5. Pour the above solution into the container containing the above particles for equal - volume impregnation. The liquid level of the solution should be at the same height as the liquid level of the solid particles. Stir once every 30 minutes during the impregnation process to ensure full contact between the solution and the particles, and continue for 12 h. After the impregnation is completed, transfer the granular mixture to an oven and dry it at 70 °C for 4 h. After drying, transfer the particles to a corundum tube and calcine them at 800 °C for 4 h in an inert gas environment to finally obtain the catalyst LHZH - 1.
[0094] Example 2
[0095] For ease of description, the catalyst prepared in this Example 2 can be called LHZH - 2 for example, and its specific preparation steps are as follows:
[0096] S1. Wash the pyrite cinder and dolomite ash with deionized water to remove impurities, and then put them into an oven and dry them at 80 °C for 12 h. Place the dried pyrite cinder and dolomite ash in a ball mill respectively, set the rotation speed of the ball mill at 200 revolutions per minute, grind them into powders and reserve them.
[0097] S2. Weigh 32.541 g of pyrite cinder powder, 32.492 g of dolomite ash powder, 14.953 g of porous molecular sieve powder and 10.023 g of kaolin powder, mix them evenly, add 40.00 ml of deionized water and stir to form a viscous mixture.
[0098] S3. Transfer the above mixture to a mold and use a jack for tablet pressing and curing. The weighing / force - measuring controller shows 1035 kg to form a sheet - shaped solid. Dry the above solid at room temperature for 8 h, then transfer it to an oven and dry it at 70 °C for 10 h. After drying is completed, transfer the sample to a muffle furnace and calcine it at 900 °C for 4 h. After the calcination is over, crush the sample into 20 - 40 mesh particles. Take a small amount of particles to test the water absorption, and the result is 0.342 ml / g. Then dry the particles and reserve them.
[0099] S4. Weigh 5.586 g of Co(NO 3 ) 2 ·6H 2 O, 4.214 g of La(NO 3 ) 3 ·6H 2 O, 4.186 g of Ce(NO 3 ) 3 ·6H 2 O, 4.354 g of Sr(NO 3 ) 2·4H2O, 30.78 ml of deionized water was added according to the water absorption of the particles to prepare a solution.
[0100] S5. Pour the above solution into the container containing the above particles for equal-volume impregnation. The liquid level of the solution should be at the same height as the liquid level of the solid particles. Stir once every 30 min during the impregnation process to ensure full contact between the solution and the particles, and continue for 12 h. After impregnation, transfer the granular mixture to an oven and dry it at 70 °C for 4 h. After drying, transfer the particles to a corundum tube and calcine them at 800 °C for 4 h in an inert gas environment to finally obtain the catalyst LHZH-2.
[0101] Example 3
[0102] For ease of description, the catalyst prepared in this Example 3 can be called LHZH-3 for example, and its specific preparation steps are as follows:
[0103] S1. Wash the pyrite cinder and dolomite ash with deionized water to remove impurities, and then put them into an oven and dry them at 80 °C for 12 h. Place the dried pyrite cinder and dolomite ash in a ball mill respectively, set the rotation speed of the ball mill at 200 revolutions per minute, grind them into powders and reserve for use.
[0104] S2. Weigh 54.153 g of pyrite cinder powder, 10.814 g of dolomite ash powder, 14.994 g of porous molecular sieve powder and 9.982 g of kaolin powder, mix them evenly, add 40.00 ml of deionized water and stir to form a viscous mixture.
[0105] S3. Transfer the above mixture to a mold and use a jack for tablet pressing and curing. The weighing / force measuring controller shows 996 kg to form a sheet-like solid. Dry the above solid at room temperature for 8 h, then transfer it to an oven and dry it at 70 °C for 10 h. After drying, transfer the sample to a muffle furnace and calcine it at 900 °C for 4 h. After calcination, crush the sample into 20 - 40 mesh particles. Take a small amount of particles to test the water absorption, and the result is 0.409 ml / g. Then dry the particles and reserve for use.
[0106] S4. Weigh 2.794 g of Co(NO 3 ) 2 ·6H 2 O, 2.105 g of La(NO 3 ) 3 ·6H 2 O, 2.095 g of Ce(NO 3 ) 3 ·6H 2 O, 2.174 g of Sr(NO 3 ) 2 ·4H 2O, 36.80 ml of deionized water was added according to the water absorption of the particles to prepare a solution.
[0107] S5. Pour the above solution into the container containing the above particles for equal-volume impregnation. The liquid level of the solution should be at the same height as the liquid level of the solid particles. Stir once every 30 minutes during the impregnation process to ensure full contact between the solution and the particles, and continue for 12 h. After the impregnation is completed, transfer the granular mixture to the oven and dry it at 70 °C for 4 h. After drying, transfer the particles to a corundum tube and calcine them at 800 °C for 4 h in an inert gas environment to finally obtain the catalyst LHZH-3.
[0108] Example 4
[0109] For ease of description, the catalyst prepared in this Example 4 can be called LHZH-4 for example, and its specific preparation steps are as follows:
[0110] S1. Wash the pyrite cinder and dolomite ash with deionized water to remove impurities, and then put them into the oven and dry them at 80 °C for 12 h. Place the dried pyrite cinder and dolomite ash in a ball mill respectively, set the rotation speed of the ball mill to 200 revolutions per minute, grind them into powder and set aside.
[0111] S2. Weigh 54.146 g of pyrite cinder powder, 10.843 g of dolomite ash powder, 15.013 g of porous γ-Al2O3 powder and 9.996 g of kaolin powder, mix them evenly, add 40.00 ml of deionized water and stir to form a viscous mixture.
[0112] S3. Transfer the above mixture to a mold and use a jack for tablet pressing and curing. The weighing / force measuring controller shows 972 kg to form a sheet solid. Dry the above solid at room temperature for 8 h, then transfer it to the oven and dry it at 70 °C for 10 h. After drying is completed, transfer the sample to a muffle furnace and calcine it at 900 °C for 4 h. After the calcination is completed, crush the sample into 20-40 mesh particles. Take a small amount of particles to test the water absorption, and the result is 0.412 ml / g. Then dry the particles and set aside.
[0113] S4. Weigh 5.582 g of Co(NO 3 ) 2 ·6H 2 O, 4.223 g of La(NO 3 ) 3 ·6H 2 O, 4.184 g of Ce(NO 3 ) 3 ·6H 2 O, 4.344 g of Sr(NO 3 ) 2 ·4H 2O, add 37.08 ml of deionized water according to the water absorption of the particles to prepare a solution.
[0114] S5. Pour the above solution into the container containing the above particles for equal-volume impregnation. The liquid level of the solution should be at the same height as the liquid level of the solid particles. Stir once every 30 minutes during the impregnation process to ensure full contact between the solution and the particles, and continue for 12 hours. After the impregnation is completed, transfer the granular mixture to the oven and dry it at 70 °C for 4 hours. After drying, transfer the particles to a corundum tube and calcine them at 800 °C for 4 hours in an inert gas environment to finally obtain the catalyst LHZH-4.
[0115] Example 5
[0116] For ease of description, the catalyst prepared in this Example 5 can be called LHZH-5 for example, and its specific preparation steps are as follows:
[0117] S1. Wash the pyrite cinder and dolomite ash with deionized water to remove impurities, and then put them into the oven and dry them at 80 °C for 12 hours. Place the dried pyrite cinder and dolomite ash in a ball mill respectively, set the rotation speed of the ball mill to 200 revolutions per minute, grind them into powder and set aside.
[0118] S2. Weigh 54.142 g of pyrite cinder powder, 10.834 g of dolomite ash powder, 14.951 g of porous ZrO2 powder and 10.009 g of kaolin powder, mix them evenly, add 40.00 ml of deionized water and stir to form a viscous mixture.
[0119] S3. Transfer the above mixture to a mold and use a jack to press and solidify it. The weighing / force measuring controller shows 1021 kg to form a sheet-like solid. Dry the above solid at room temperature for 8 hours, and then transfer it to the oven and dry it at 70 °C for 10 hours. After drying is completed, transfer the sample to a muffle furnace and calcine it at 900 °C for 4 hours. After the calcination is completed, crush the sample into 20-40 mesh particles. Take a small amount of particles to test the water absorption, and the result is 0.395 ml / g. Then dry the particles and set aside.
[0120] S4. Weigh 5.579 g of Co(NO 3 ) 2 ·6H 2 O, 4.204 g of La(NO 3 ) 3 ·6H 2 O, 4.185 g of Ce(NO 3 ) 3 ·6H 2 O, 4.313 g of Sr(NO 3 ) 2 ·4H 2O, 35.55 ml of deionized water was added according to the water absorption of the particles to prepare a solution.
[0121] S5. Pour the above solution into the container containing the above particles for equal-volume impregnation. The liquid level of the solution should be at the same height as the liquid level of the solid particles. Stir once every 30 min during the impregnation process to ensure full contact between the solution and the particles, and continue for 12 h. After the impregnation is completed, transfer the granular mixture to an oven and dry it at 70 °C for 4 h. After drying, transfer the particles to a corundum tube and calcine them at 800 °C for 4 h in an inert gas environment to finally obtain the catalyst LHZH-5.
[0122] Example 6
[0123] For ease of description, the catalyst prepared in this Example 6 is called LHZH-6, and its specific preparation steps are as follows:
[0124] The preparation steps of this Example 6 are basically the same as those of Example 1, except that in this Example 6, the swelling agent is selected as a mixture of porous molecular sieve, porous γ-Al 2 O 3 and porous ZrO 2 powder, where the mass of the porous molecular sieve is 5.004 g, the mass of the porous γ-Al 2 O 3 is 4.989 g, and the mass of the porous ZrO 2 is 4.990 g. The total mass of the swelling agent added remains unchanged, and finally the catalyst LHZH-6 is obtained.
[0125] Example 7
[0126] For ease of description, the catalyst prepared in this Example 7 is called LHZH-7, and the specific preparation steps are as follows:
[0127] The preparation steps of this example are basically the same as those of Example 1, except that in this Example 7, citric acid is selected as the binder. The mass of citric acid is 10.012 g, and after being prepared into a solution with 40.00 ml of deionized water, it is added to the mixed powder of the active component and the swelling agent. The total mass of the binder added remains unchanged, and finally the catalyst LHZH-7 is obtained.
[0128] Example 8
[0129] For ease of description, the catalyst prepared in this Example 8 is called LHZH-8, and the specific preparation steps are as follows:
[0130] The preparation steps of this example are basically the same as those of Example 1, except that in Example 8, the binder is a mixture of citric acid solution and kaolin powder, where the mass of kaolin powder is 5.012 g and the mass of citric acid is 5.000 g. The kaolin powder is preferentially added to the mixed powder of the active component and the swelling agent. After citric acid is added to 40.00 ml of deionized water to form a solution, it is added to the mixed powder of kaolin, active component and swelling agent. The total mass of the added binder remains unchanged, and finally the catalyst LHZH-8 is obtained.
[0131] Example 9
[0132] For ease of description, the catalyst prepared in this Example 9 is designated as LHZH-9, and the specific preparation steps are as follows:
[0133] The preparation steps of this example are basically the same as those of Example 1, except that in this Example 9, no cocatalytic component is added, and finally the catalyst LHZH-9 is obtained.
[0134] Example 10
[0135] For ease of description, the catalyst prepared in this Example 10 is designated as LHZH-10, and the specific preparation steps are as follows:
[0136] The preparation steps of this example are basically the same as those of Example 1, except that in this Example 10, only 5.588 g of Co(NO 3 ) 2 ·6H 2 O is added as the cocatalytic component. The mass of the added Co(NO 3 ) 2 ·6H 2 O remains unchanged, and finally the catalyst LHZH-10 is obtained.
[0137] Example 11
[0138] For ease of description, the catalyst prepared in this Example 11 is designated as LHZH-11, and the specific preparation steps are as follows:
[0139] The preparation steps of this example are basically the same as those of Example 1, except that in this Example 11, only 4.210 g of La(NO 3 ) 3 ·6H 2 O is added as the cocatalytic component. The mass of the added La(NO 3 ) 3 ·6H 2 O remains unchanged, and finally the catalyst LHZH-11 is obtained.
[0140] Example 12
[0141] For ease of description, the catalyst prepared in Example 12 is designated as LHZH-12, and the specific preparation steps are as follows:
[0142] The preparation steps of this example are basically the same as those of Example 1, except that in Example 12, only 4.190 g of Ce(NO 3 ) 3 ·6H 2 O is added as the cocatalytic component. The mass of the added Ce(NO 3 ) 3 ·6H 2 O remains unchanged, and finally the catalyst LHZH-12 is obtained.
[0143] Example 13
[0144] For ease of description, the catalyst prepared in Example 13 is designated as LHZH-13, and the specific preparation steps are as follows:
[0145] The preparation steps of Example 13 are basically the same as those of Example 1, except that in Example 13, only 4.350 g of Sr(NO 3 ) 2 ·4H 2 O is added as the cocatalytic component. The mass of the added Sr(NO 3 ) 2 ·4H 2 O remains unchanged, and finally the catalyst LHZH-13 is obtained.
[0146] Verification Example
[0147] In this verification example, methylnaphthalene is specifically used as the tar model compound, and H 2 O, O 2 , H 2 , CH 4 , CO and CO 2 are introduced to prepare simulated raw coal gas, and the gas components are shown in Table 1 below. At the same time, the conversion rate of methylnaphthalene and the yield of syngas (CO + H 2 ) are used as the catalyst performance detection criteria.
[0148] Table 1 Composition of Simulated Raw Coal Gas
[0149]
[0150] The reaction device, reaction conditions, and detection process in this verification example are as described below.
[0151] Reaction device: A high-temperature corundum reaction tube (99.5% Al 2 O 3 , Φ14×2×1000 mm) is used, equipped with silicon carbide rods as heating elements, and the temperature is controlled by a distributed S-type thermocouple.
[0152] Reaction conditions: atmospheric pressure, reaction temperature 800 °C, space velocity 1800 h-1.
[0153] Process for detecting catalyst activity: 10.0 ± 0.1 g of the catalysts prepared in Examples 1-8 above were respectively loaded into the above reaction device, and simulated raw coal gas was introduced under the reaction conditions to detect the catalyst activity. The detection time was 20 h (after stabilization), and samples were taken every 6 h for data analysis by gas chromatography.
[0154] The test results of the relevant properties of the catalyst are shown in Table 2 below.
[0155] Table 2 Parameter and performance test results of examples
[0156]
[0157] According to the test results of the relevant properties of the catalyst shown in Table 2, the high-temperature raw coal gas cracking and conversion catalyst mainly exhibits two activity evolution laws: one is that the catalytic activity shows a monotonically increasing trend to a stable state with the reaction time; the other shows an activity change characteristic of increasing first and then decreasing. This phenomenon can be attributed to the lattice oxygen migration mechanism of Fe 2 O 3 as the main active component during the reaction process.
[0158] More specifically, Fe 2 O 3 selectively releases lattice oxygen in a reducing atmosphere, promoting the formation of CO, and being reduced to low-valent iron itself. This phase change process effectively improves the initial activity of the catalyst. However, with the prolongation of the reaction time, deactivation phenomena such as carbon deposition and high-temperature sintering gradually occur on the surface of some catalysts in the examples, so that the active sites of the catalyst are covered, the grains of the active components grow, and the specific surface area decreases, ultimately leading to the attenuation of the catalyst activity.
[0159] Comparing the experimental data of LHZH-1 and LHZH-2 catalysts shows that when the ratio of pyrite cinder to dolomite ash in the active component is low, the lattice oxygen migration capacity of the catalyst is significantly improved, and the CO selectivity and catalyst activity increase accordingly. However, too little dolomite ash content will reduce the charge compensation effect of the basic mineral components in the catalyst on the acidic active sites and its chemical adsorption inhibition effect on the carbon deposition precursors, resulting in a weakening of the structural stability of the catalyst, the catalyst's anti-poisoning and anti-coking capabilities.
[0160] Comparing the experimental data of LHZH-1 and LHZH-3 catalysts shows that when the content of each element in the co-activating component decreases from 2% to 1%, the activity and stability of the catalyst decrease to a certain extent. Combining the analysis of LHZH-9 to LHZH13, in the system without the co-catalytic component, the activity of the catalyst drops significantly, and deactivation occurs during the 18-hour detection, possibly because the release of lattice oxygen in the catalyst slows down, and carbon deposition and carbon accumulation lead to catalyst deactivation. Adding a single additive can only partially optimize a certain performance dimension of the catalyst through a specific mechanism. For example, Co 2+ / Co 3+ The redox performance of can improve the reducibility of iron oxides, and La 2 O 3 The basic sites of can inhibit carbon deposition, and the multi-metal synergistic catalysis mechanism is a necessary condition to simultaneously achieve high activity, high redox performance, anti-sintering performance and anti-carbon deposition performance.
[0161] Comparing the experimental data of LHZH-1 and LHZH-4 to LHZH-6 series catalysts shows that the difference in the type of diluent has a major impact on the catalyst performance mainly due to the specific surface area of the diluent. The specific surface area of the porous molecular sieve reaches 482.351 m 2 / g, much higher than that of porous γ-Al 2 O 3 (231.715 m 2 ) and porous ZrO 2 (196.551 m 2 / g), thus enabling the LHZH-1 catalyst to exhibit the optimal catalytic activity.
[0162] Comparing the experimental data of LHZH-1, LHZH-7 and LHZH-8 series catalysts shows that the change in the type of binder has no obvious effect on the performance of the catalyst. The binder mainly plays the functions of physical adhesion and improving mechanical strength during the catalyst preparation process and has no chemical synergistic effect.
[0163] It can be seen from the above examples that the catalyst preparation process of this embodiment is simple and has a short preparation process. The preparation of the high-temperature waste gas cracking conversion catalyst is completed by drying, roasting and equal-volume impregnation, avoiding the complex volume calculation and adjustment in the traditional impregnation process. Using pyrite cinder and dolomite ash as the basic catalyst belongs to the secondary utilization of industrial waste residues and the optimized use of natural ores, with excellent economic benefits and a green prospect.
[0164] Meanwhile, the catalyst of the above example itself has good catalytic activity and can efficiently promote the cracking and conversion of high-temperature raw coal gas into low-carbon hydrocarbons or small-molecule substances. The addition of promoters such as Sr, Co, La, and Ce not only enables the catalyst to be better applied in the cracking and conversion process of raw coal gas, but also further improves the catalytic efficiency of the catalyst. Finally, through the drying and calcination treatment of the catalyst, its stability and durability are ensured, and the ability of the catalyst to operate stably for a long time can be improved.
[0165] The above are only the preferred examples of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A catalyst for cracking conversion reaction of raw coal gas, characterized in that: The components of the catalyst include a main active component, a co-catalyst component, a capacity expander and a binder; The main active components include industrial waste residues and natural ores; The co-catalytic component is selected from any one or a mixture of oxides of Group IIA elements, oxides of Group VIII elements and oxides of lanthanide elements; The expansion agent is selected from any one or a mixture of γ-Al2O3, TiO2, SiO2, ZrO2 and molecular sieves; The adhesive is selected from any one or a mixture of citric acid, sodium silicate, silica sol, methyl cellulose, sesbania powder, silicone oil, chitosan and kaolin.
2. The catalyst according to claim 1, characterized in that: The mass fraction of each component in the catalyst is 50.0-70.0% of the main active component, 1.0-10.0% of the co-catalyst component, 10.0-15.0% of the capacity expander, and 5.0-10.0% of the binder.
3. The catalyst according to claim 1, characterized in that: The industrial waste slag is selected from any one of pyrite oxidized roasting slag and steel slag or a mixture of the two; and / or, The natural ore is selected from any one or a mixture of dolomite, olivine and zeolite; and / or, The oxide of the Group IIA element is selected from any one of an oxide of Sr and an oxide of Ba or a mixture of both; and / or, The oxide of the Group VIII element is selected from any one of Co oxide, Rh oxide, Pt oxide and Pd oxide or a mixture of several thereof; and / or, The oxide of the lanthanide element is selected from any one of La oxide and Ce oxide or a mixture of both; and / or, The molecular sieve is selected from any one of 3A molecular sieve, 4A molecular sieve and 5A molecular sieve or a mixture of several of them.
4. The catalyst according to claim 3, characterized in that: The mass content of iron oxide in the pyrite oxidized roasted slag and the steel slag is 40.0% to 90.0%; and / or, The total mass content of CaO and MgO in the dolomite is 90.0-99.0%; and / or, The Sr oxide is SrO; and / or, The Co oxide is Co3O4; and / or, The La oxide is La2O3; and / or, The Ce oxide is CeO2.
5. The method for preparing the catalyst according to any one of claims 1 to 4, characterized in that: The preparation method comprises: The main active component is washed, dried and then ground to obtain an original powder; The original powder is mixed with the expander, and the binder is mixed with deionized water to form a solution or a solid-liquid mixture; Adding the solution or the solid-liquid mixture to the mixture of the original powder and the expander, stirring to obtain a viscous mixture; Pressing the viscous mixture into a shape and drying it to form solid particles; Deionized water is used to dissolve the promoter component to obtain a promoter solution, and the promoter solution is added to the solid particles, and the solid particles are impregnated, dried, and calcined in sequence to obtain the catalyst.
6. The method for preparing the catalyst according to claim 5, characterized in that: The main active component is washed, dried and then ground to obtain an original powder, comprising: The industrial waste residue and the natural ore are respectively placed in deionized water for washing, and dried in a first preset temperature environment for a first preset time; The dried industrial waste slag and the natural ore are respectively placed in a ball mill, and ground at a preset speed for a second preset time to obtain industrial waste slag powder and natural ore powder; The industrial waste slag powder and the natural ore powder are mixed according to a preset ratio to obtain the original powder.
7. The method for preparing the catalyst according to claim 6, characterized in that: The preset ratio is 1:0.2~1.
8. The method for preparing the catalyst according to claim 5, characterized in that: The step of mixing the binder with deionized water to form a solution or a solid-liquid mixture comprises: According to the mass of the mixture of the original powder and the expander, deionized water is weighed in a preset proportion; The binder is mixed with the weighed deionized water to form the solution or the solid-liquid mixture.
9. The method for preparing a catalyst according to claim 5, characterized in that: The drying of the viscous mixture after compression molding includes the following drying processes performed in sequence: drying at room temperature for a third preset time; Drying at a second preset temperature until there is no moisture on the surface; The process is performed under an inert environment and fired at a third preset temperature for a fourth preset time.
10. The method for preparing a catalyst according to claim 5, characterized in that: After the auxiliary agent solution is added to the solid particles, the impregnation, drying and calcination are performed in sequence: The impregnation includes impregnating the solid particles added with the auxiliary agent solution at room temperature; The drying comprises heating the impregnated solid particles to a fourth preset temperature until no water remains; The calcining includes calcining in an inert gas atmosphere at a fifth preset temperature for a fifth preset time.