Iron-manganese-based oxygen carrier as well as preparation method and application thereof

Abstract

The invention relates to an iron-manganese-based oxygen carrier as well as a preparation method and application thereof. The iron-manganese-based oxygen carrier comprises the following raw materials: aluminum oxide, magnesium oxide, iron oxide, manganese oxide and the like, and the molar ratio of aluminum to magnesium to iron to manganese is 1: (0.5-2): (1-4): (0-1). The preparation method of the iron-manganese-based oxygen carrier comprises the steps of (1) precursor preparation, (2) granulation, (3) heat treatment and (4) screening, and the iron-manganese-based oxygen carrier has the advantages of being environmentally friendly, controllable in cost, high in fluidization strength, high in oxygen carrying activity and capable of being thermally repaired and is suitable for a double-circulation fluidized bed for actual industrial chemical looping combustion and gasification.

Description

Technical Field

[0001] This article relates to the field of oxygen carrier materials for chemical looping combustion, and specifically to a method for preparing oxygen carriers with high fluidization strength, high oxygen-carrying activity, and high-temperature thermal repairability for chemical looping combustion and gasification using raw materials such as metal oxides of iron, magnesium, and aluminum. Background Technology

[0002] Carbon dioxide emissions from coal combustion and coal chemical industries are a major source of greenhouse gases in the atmosphere. Carbon capture, utilization, and storage (CCUS) is the most effective means of controlling carbon dioxide emissions from large-scale industries such as thermal power generation and coal chemical industry, with carbon capture being the key component.

[0003] Chemical looping combustion (CLC) is a carbon capture technology used in combustion. Unlike traditional combustion processes, CLC separates air from fuel instead of allowing them to react directly. Instead, it uses an oxygen carrier (OC) composed of metal oxides or similar materials to transfer and react oxygen in the form of lattice oxygen. A CLC device can be broadly divided into two parts: an air reactor and a fuel reactor. In the air reactor, the oxygen carrier only undergoes an oxidation reaction with oxygen to replenish lattice oxygen. Once in the air-isolated fuel reactor, the oxidized oxygen carrier reacts with fuel and reducing gases, releasing its lattice oxygen and leaving the oxygen carrier. The reduced oxygen carrier returns to the air reactor for recycling. Under ideal conditions, no additional oxygen carrier is needed, saving on raw material costs.

[0004] Chemical looping combustion and gasification technology, in principle, achieves staged energy release and utilization, as well as the separation of flue gas and air, at low cost. However, scaling up laboratory-scale reactors to industrial-scale applications presents practical problems such as deviating from ideal conditions and increasing raw material and energy costs. Traditional laboratory-scale artificial synthesis of oxygen carriers often involves impregnating alumina microspheres with nitrate solutions, resulting in high costs for large-scale industrial production and difficult-to-treat wastewater and heavy metal contamination. The complex conditions in actual industrial operation place higher demands on the fluidization intensity of oxygen carriers and necessitate rapid repair and reuse of degraded oxygen carriers. Summary of the Invention

[0005] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of protection of this application.

[0006] To address the losses in oxygen carriers under complex fluidization conditions in actual industrial operation due to friction between particles and between particles and the wall, as well as structural damage after multiple redox cycles, this application employs an artificial granulation method to synthesize oxygen carriers, directly controlling the composition and performance of the oxygen carrier from the raw material ratio. Based on the composition and temperature of the phase diagram, a spinel structure composed of alumina, magnesium oxide, iron oxide, and manganese oxide is prepared. Combined with granulation, a high fluidization strength oxygen carrier is obtained. The iron-manganese-based oxygen carrier described in this application experiences a decrease in strength after multiple cycles, which can be repaired through heat treatment to restore its original high strength. Furthermore, addressing the challenge of balancing cost, environmental protection, strength, activity, and reusability in industrial-grade oxygen carriers, this application utilizes cost-effective metal oxides, powder granulation, and heat treatment to reduce raw material and preparation process costs and potential pollution. By scientifically adjusting the raw material ratios and optimizing the process flow, the oxygen carrier maintains high oxygen-carrying activity even at high strength, and the physicochemical damage received during chemical looping is structurally reversible, facilitating low-cost repair.

[0007] The first aspect of this application provides an iron-manganese-based oxygen carrier, wherein the raw materials of the iron-manganese-based oxygen carrier include nano-γ-alumina, nano-magnesium oxide, ferric oxide, and manganese tetroxide, wherein the molar ratio of aluminum, magnesium, iron, and manganese is 1:(0.5-2):(1-4):(0-1). The main active components of the iron-manganese-based oxygen carrier are iron and manganese elements.

[0008] In one exemplary embodiment, the iron-manganese-based oxygen carrier has a spinel structure.

[0009] In one exemplary embodiment, the particle size of the nano-γ-alumina and the nano-magnesium oxide is less than 10 μm; Preferably, the particle size of the nano-γ-alumina and the nano-magnesium oxide is less than 5 μm.

[0010] In one exemplary embodiment, the molar ratio of aluminum, magnesium, and iron in the raw materials of the iron-manganese-based oxygen carrier is 1:0.5:1 or 1:0.5:3.

[0011] In one exemplary embodiment, the molar ratio of aluminum, magnesium, iron, and manganese in the raw materials of the iron-manganese-based oxygen carrier is 1:0.5:3:0.5.

[0012] In one exemplary embodiment, the iron-manganese-based oxygen carrier can be thermally repaired after its strength decreases due to repeated cycles by undergoing high-temperature heat treatment at 1200-1600℃ for 1-5 hours, restoring its performance to the level of a fresh oxygen carrier.

[0013] In one exemplary embodiment, the iron-manganese-based oxygen carrier has particles with a diameter of 1 mm that have a crushing force greater than 40 N and a high fluidization intensity.

[0014] In one exemplary embodiment, the iron-manganese-based oxygen carrier has an oxygen-carrying capacity greater than 2% and high oxygen-carrying activity.

[0015] The second aspect of this application provides a method for preparing the above-mentioned iron-manganese-based oxygen carrier, comprising: 1) Preparation of oxygen carrier precursor, including: thoroughly and uniformly mixing dry raw materials that meet the particle size requirements with a binder to form an iron-manganese-based oxygen carrier precursor; 2) Oxygen carrier granulation, including: the iron-manganese-based oxygen carrier precursor is mixed with water to form a semi-solid polymer and then granulated, and the oxygen carrier microspheres are obtained by primary screening. 3) High-temperature heat treatment, including: drying the wet oxygen carrier microspheres to obtain dry oxygen carrier material, and performing high-temperature heat treatment at a high temperature to obtain the heat-treated oxygen carrier finished product; and 4) Screening of the oxygen carrier product, including: cooling and screening the heat-treated oxygen carrier product, and screening it according to its strength and activity to obtain the high-strength and high-activity iron-manganese-based oxygen carrier product.

[0016] In one exemplary embodiment, the molar ratio of aluminum oxide, magnesium oxide, iron oxide, and manganese oxide in the iron-manganese-based oxygen carrier precursor satisfies the requirement for forming a spinel structure at high temperature.

[0017] In one exemplary embodiment, the total content of ferric oxide and manganese tetroxide in the iron-manganese-based oxygen carrier precursor is more than 50% by mass percentage.

[0018] In one exemplary embodiment, the binder is dextrin or starch.

[0019] In one exemplary embodiment, the binder content in the iron-manganese-based oxygen carrier precursor is 5% to 10% by mass. In one exemplary embodiment, in step 1), the mixing is mechanical mixing, ball milling mixing, or mixing in the form of a slurry.

[0020] In one exemplary embodiment, step 2) includes, but is not limited to, disc rolling granulation, spray granulation, compression molding, sol-gel method, etc.

[0021] In one exemplary embodiment, in step 2), the particle size range of the primary sieve is 0.3-5 mm.

[0022] In an exemplary embodiment, step 2) includes: slowly adding water to the iron-manganese-based oxygen carrier precursor during continuous stirring to prepare a semi-solid polymer with the required humidity and then granulating it to obtain wet oxygen carrier microspheres with a particle size of 0.3-5 mm through initial screening.

[0023] In one exemplary embodiment, in step 2), the amount of water added is 10%-100% of the solid mass.

[0024] In one exemplary embodiment, in step 3), the drying conditions are: drying in an oven at 90-300°C for 4-24 hours.

[0025] In one exemplary embodiment, in step 3), the drying conditions are: a temperature of 150°C and a time of 12 hours.

[0026] In one exemplary embodiment, in step 3), the apparatus for high-temperature heat treatment is a fluidized bed calcining furnace, rotary kiln, tunnel kiln, or shuttle kiln, etc.

[0027] In one exemplary embodiment, in step 3), the high-temperature heat treatment is performed at a temperature of 1200-1600°C for a time of 1-5 hours. Preferably, the high-temperature heat treatment is performed at a temperature of 1600°C for 2 hours.

[0028] In one exemplary embodiment, in step 4), the particle size range of the sieving is 0.5-3 mm.

[0029] The third aspect of this application provides an iron-manganese-based oxygen carrier prepared by the above method.

[0030] The fourth aspect of this application provides the application of the aforementioned iron-manganese-based oxygen carrier in chemical looping combustion and gasification processes.

[0031] Compared with the prior art, this application mainly has the following technical effects: (1) Environmentally friendly. The raw materials used are alumina, magnesium oxide, iron oxide, manganese oxide and other materials with low leaching toxicity, resulting in less wastewater and fewer harmful substances generated during the treatment process.

[0032] (2) Cost controllable. Raw materials are simple and readily available, and the cost of raw materials in large quantities is controllable. The granulation and heat treatment equipment in the preparation process is relatively mature, and the research and development and construction costs of the equipment are controllable. The energy consumption cost in the preparation process is within a reasonable range.

[0033] (3) High fluidization strength. According to the phase diagram, the proportioned metal oxides, after heat treatment at an appropriate temperature, generate spinel-like minerals with a robust structure, exhibiting high wear resistance in the fluidized bed reactor and transport cycle of the chemical chaining process, thus avoiding losses. The crushing force measured in a laboratory-grade force gauge exceeds 40 N.

[0034] (4) High oxygen-carrying activity. The content of oxides of metal elements with variable valence states, such as iron and manganese, in the composition of the oxygen carrier is higher than 50%. The increase in redox components improves the oxygen-carrying capacity of the oxygen carrier. In laboratory-level redox cycle tests, the mass difference between the reduced and oxidized states accounts for more than 2% of the total mass of the oxygen carrier, that is, the oxygen carrying rate is higher than 2%.

[0035] (5) Thermal repairable. After multiple redox cycles during chemical looping combustion or gasification, the original high-strength and high-activity fresh oxygen carrier undergoes phase separation due to the combined effects of physical wear and chemical reaction, resulting in a decrease in strength and activity. By improving the thermal repair process to the same conditions as the heat treatment reaction during preparation, the oxygen carrier with reduced strength can be thermally repaired to a level comparable to that of the fresh oxygen carrier.

[0036] Therefore, this iron-manganese-based oxygen carrier has the advantages of being environmentally friendly, cost-controllable, having high fluidization intensity, high oxygen-carrying activity, and being thermally repairable. These advantages make this invention have a wide range of industrial applications in fluidized chemical looping combustion scenarios.

[0037] In summary, this application synthesizes a spinel-structured iron-manganese-based oxygen carrier using alumina, magnesium oxide, iron oxide, and manganese oxide as raw materials through granulation and heat treatment. This oxygen carrier is intended for practical industrial applications in chemical looping combustion and gasification. The preparation process utilizes environmentally friendly raw materials and methods, employing conventional oxides and mature processes, resulting in controllable costs. By scientifically and flexibly controlling the composition of each raw material during the artificial synthesis of the chemical looping oxygen carrier, and optimizing parameters such as auxiliary materials, time, particle size, and temperature during granulation and heat treatment, the performance of the final iron-manganese-based oxygen carrier is significantly influenced. This results in an oxygen carrier with high fluidization strength and high oxygen-carrying activity. The spinel-structured oxygen carrier exhibits performance recovery after heat treatment.

[0038] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the embodiments described in the description and the accompanying drawings. Attached Figure Description

[0039] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0040] Figure 1 This is a flowchart illustrating the preparation process of the iron-manganese-based oxygen carrier in this application. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0042] Example 1: 1) Preparation of oxygen carrier precursor: Take 10g of nano-γ alumina, 4g of nano-magnesium oxide, 16g of ferric oxide, and 3g of dextrin and mix them thoroughly to obtain the oxygen carrier precursor; wherein, the particle size of nano-γ alumina and nano-magnesium oxide is less than 5 μm. 2) Oxygen carrier granulation: Slowly add a small amount of deionized water to the oxygen carrier precursor while continuously stirring until the oxygen carrier precursor gradually agglomerates from dry powder to form a colloidal semi-solid polymer; take a small amount of the colloidal semi-solid polymer for pressing and disc rolling granulation to generate wet spheres with a diameter of 0.5-3 mm. 3) High-temperature heat treatment: The wet pellets were dried in a drying oven at 105℃ for 12 hours; then they were heat-treated in a high-temperature muffle furnace at 1600℃ for 2 hours. 4) Screening of finished oxygen carrier: After heat treatment and cooling, the pellets are taken out and screened to obtain oxygen carrier pellets with a final particle size of 1-3 mm.

[0043] The crushing force of a 1mm particle, as measured by the force gauge, was greater than 63N. After 100 cycles in a 20% hydrogen and air atmosphere, the oxygen loading rate was 2.1%, and the crushing force decreased to 37N. After heat repair at 1600℃ for 2 hours, the crushing force recovered to 60N, and the oxygen loading rate was 2.4% after 100 cycles.

[0044] Example 2: 1) Preparation of oxygen carrier precursor: Take 10g of nano-γ alumina, 4g of nano-magnesium oxide, 48g of ferric oxide, and 6g of dextrin and mix them thoroughly to obtain the oxygen carrier precursor; wherein, the particle size of nano-γ alumina and nano-magnesium oxide is less than 5 μm. 2) Oxygen carrier granulation: Slowly add a small amount of deionized water to the oxygen carrier precursor while continuously stirring until the oxygen carrier precursor gradually agglomerates from dry powder to form a colloidal semi-solid polymer; take a small amount of the colloidal semi-solid polymer for pressing and disc rolling granulation to generate wet spheres with a diameter of 0.5-3 mm. 3) High-temperature heat treatment: The wet pellets were dried in a drying oven at 105℃ for 12 hours; then heat-treated in a high-temperature muffle furnace at 1600℃ for 2 hours. 4) Screening of finished oxygen carrier: After heat treatment and cooling, the pellets are taken out and screened to obtain 1-3 mm oxygen carrier pellets of the final product.

[0045] The force gauge measured a crushing force of 42 N for a 1 mm particle size. After 100 cycles in a 20% hydrogen and air atmosphere, the oxygen loading rate was 3.6%, and the crushing force decreased to 20 N. After heat repair at 1600℃ for 2 hours, the crushing force recovered to 40 N, and the oxygen loading rate was 3.7% after 100 cycles.

[0046] Example 3: 1) Preparation of oxygen carrier precursor: Take 10g of nano-γ-alumina, 4g of nano-magnesium oxide, 48g of ferric oxide, 7g of manganese tetroxide, and 6g of dextrin and mix them thoroughly to obtain the oxygen carrier precursor; wherein, the particle size of nano-γ-alumina and nano-magnesium oxide is less than 5 μm. 2) Oxygen carrier granulation: Slowly add a small amount of deionized water to the oxygen carrier precursor while continuously stirring until the oxygen carrier precursor gradually agglomerates from dry powder to form a colloidal semi-solid polymer; take a small amount of the colloidal semi-solid polymer for pressing and disc rolling granulation to generate wet spheres with a diameter of 0.5-3 mm. 3) High-temperature heat treatment: The wet pellets were dried in a drying oven at 105℃ for 12 hours; then heat-treated in a high-temperature muffle furnace at 1600℃ for 2 hours. 4) Screening of finished oxygen carrier: After heat treatment and cooling, the pellets are taken out and screened to obtain 1-3 mm oxygen carrier pellets of the final product.

[0047] The force gauge measured a crushing force of 79 N for a 1 mm particle size. After 100 cycles in a 20% hydrogen and air atmosphere, the oxygen loading rate was 2.4%, and the crushing force decreased to 53 N. After heat repair at 1600℃ for 2 hours, the crushing force recovered to 76 N, and the oxygen loading rate was 2.3% after 100 cycles.

[0048] Comparative Example 1: Take 10g of nano-gamma alumina, 64g of ferric oxide, and 7.4g of dextrin. Mix all raw materials thoroughly to obtain a granulation precursor. Slowly add a small amount of deionized water to the granulation precursor while continuously stirring until the precursor gradually agglomerates from a dry powder to form a colloidal semi-solid. Take a small amount of the colloidal precursor and press it into shape, then granulate it using a disc rolling process to generate wet microspheres with a diameter of 0.5-3 mm. Dry the wet microspheres in a drying oven at 105℃ for 12 hours, then heat-treat them in a high-temperature muffle furnace at 1600℃ for 2 hours. After heat treatment and cooling, remove the microspheres from the crucible and sieve to obtain the final product of 1-3 mm oxygen-carrying microspheres.

[0049] The force gauge measured a crushing force of 45 N for a 1 mm particle size. After 100 cycles in a 20% hydrogen and air atmosphere with an oxygen loading rate of 1.5%, the crushing force decreased to 22 N, which did not meet the activity requirements. After heat repair at 1600℃ for 2 hours, the crushing force recovered to 42 N.

[0050] Comparative Example 2: Take 10g of nano-γ-alumina, 4g of magnesium oxide, 8g of manganese tetroxide, and 2g of dextrin. The nano-γ-alumina has a particle size of less than 5 μm. All raw materials are thoroughly mixed to obtain a granulation precursor. A small amount of deionized water is slowly added to the granulation precursor while continuously stirring until the precursor gradually agglomerates from a dry powder to form a colloidal semi-solid. A small amount of the colloidal precursor is pressed and granulated using a disc rolling process to generate wet microspheres with a diameter of 0.5-3 mm. The wet microspheres are dried in a drying oven at 105℃ for 12 h and then heat-treated in a high-temperature muffle furnace at 1600℃ for 2 h. After heat treatment and cooling, the microspheres are removed from the crucible and screened to obtain 1-3 mm oxygen-carrying microspheres of the final product.

[0051] The force gauge measured a crushing force of 61 N for a 1 mm particle size. After 100 cycles in a 20% hydrogen and air atmosphere with an oxygen loading rate of 0.7%, the crushing force decreased to 44 N, which did not meet the activity requirements. After heat repair at 1600℃ for 2 hours, the crushing force recovered to 58 N.

[0052] Comparative Example 3: Take 10g of nano-gamma alumina, 16g of ferric oxide, 8g of manganese tetroxide, and 3g of dextrin. Mix all raw materials thoroughly to obtain a granulation precursor. Slowly add a small amount of deionized water to the granulation precursor while continuously stirring until the precursor gradually agglomerates from a dry powder to form a colloidal semi-solid. Take a small amount of the colloidal precursor and press it into shape using a disc granulation process to generate wet microspheres with a diameter of 0.5-3 mm. Dry the wet microspheres in a drying oven at 105℃ for 12 hours, and then heat-treat them in a high-temperature muffle furnace at 1600℃ for 2 hours. After heat treatment and cooling, remove the microspheres from the crucible and sieve to obtain the final product of 1-3 mm oxygen-carrying microspheres.

[0053] The force gauge measured a crushing force of 73 N for a 1 mm particle size. After 100 cycles in a 20% hydrogen and air atmosphere with an oxygen loading rate of 0.7%, the crushing force decreased to 30 N, failing to meet the activity requirements. After heat repair at 1600℃ for 2 hours, the crushing force recovered to 72 N.

[0054] Comparative Example 4: Take 10g of nano-gamma alumina, 4g of magnesium oxide, 16g of ferric oxide, 10g of manganese tetroxide, and 4g of dextrin. Mix all raw materials thoroughly to obtain a granulation precursor. Slowly add a small amount of deionized water to the granulation precursor while continuously stirring until the precursor gradually agglomerates from a dry powder to form a colloidal semi-solid. Take a small amount of the colloidal precursor and press it into shape using a disc granulation process to generate wet microspheres with a diameter of 0.5-3 mm. Dry the wet microspheres in a drying oven at 105℃ for 12 hours, and then heat-treat them in a high-temperature muffle furnace at 1600℃ for 2 hours. After heat treatment and cooling, remove the microspheres from the crucible and sieve to obtain the final product of 1-3 mm oxygen-carrying microspheres.

[0055] The force gauge measured a crushing force of 138 N for a 1 mm particle size. After 100 cycles in a 20% hydrogen and air atmosphere with an oxygen loading rate of 0.6%, the crushing force decreased to 80 N, failing to meet the activity requirements. After heat repair at 1600℃ for 2 hours, the crushing force recovered to 135 N.

[0056] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An iron-manganese-based oxygen carrier, raw materials of the iron-manganese-based oxygen carrier comprising nano-gamma-aluminum oxide, nano-magnesium oxide, iron sesquioxide, trimanganese tetraoxide, wherein, The molar ratio of aluminum, magnesium, iron and manganese is 1:(0.5-2):(1-4):(0-1).

2. The iron-manganese-based oxygen carrier according to claim 1, wherein, The raw materials of the iron-manganese-based oxygen carrier include nano γ-alumina, nano magnesia, and ferric oxide, wherein the molar ratio of aluminum, magnesium and iron is 1:0.5:1 or 1:0.5:3; or The raw materials of the iron-manganese-based oxygen carrier include nano γ-alumina, nano magnesia, ferric oxide, and trimanganese tetroxide, wherein the molar ratio of aluminum, magnesium, iron and manganese is 1:0.5:3:0.

5.

3. The iron-manganese-based oxygen carrier according to claim 1 or 2, wherein, The particle size of the nano γ-alumina and the nano magnesia is less than 10 μm.

4. The iron-manganese-based oxygen carrier according to claim 1 or 2, wherein, The iron-manganese-based oxygen carrier has a spinel structure; and / or The iron-manganese-based oxygen carrier can be thermally repaired by high-temperature heat treatment at 1200-1600 ℃ for 1-5 h after multiple cycles of strength reduction; and / or In the iron-manganese-based oxygen carrier, the particle crushing force of particles with a particle size of 1 mm is greater than 40 N, and the oxygen carrying capacity of the iron-manganese-based oxygen carrier is greater than 2%.

5. A method for preparing the iron-manganese-based oxygen carrier according to any one of claims 1 to 4, comprising: 1) preparation of an oxygen carrier precursor, including: uniformly mixing dry raw materials meeting particle size requirements with a binder to form an iron-manganese-based oxygen carrier precursor; 2) oxygen carrier granulation, including: adjusting the iron-manganese-based oxygen carrier precursor with water to a semi-solid polymer and performing granulation treatment, and obtaining wet oxygen carrier pellets through primary screening; 3) high-temperature heat treatment, including: drying the wet oxygen carrier pellets to obtain dry oxygen carrier pellets, and performing high-temperature heat treatment at high temperature to obtain oxygen carrier heat treatment products; and 4) screening of oxygen carrier finished products, including: cooling, screening and screening according to strength and activity of the oxygen carrier heat treatment products to obtain high-strength and high-activity iron-manganese-based oxygen carrier finished products.

6. The method of claim 5, wherein, In the iron-manganese-based oxygen carrier precursor, the molar ratio of aluminum oxide, magnesium oxide, iron oxide and manganese oxide meets the proportion of high-temperature formation of a spinel structure; and / or In the iron-manganese-based oxygen carrier precursor, the total content of ferric oxide and trimanganese tetroxide is more than 50% by mass; and / or The binder is dextrin or starch; and / or In the iron-manganese-based oxygen carrier precursor, the content of the binder is 5% to 10% by mass.

7. The method of claim 5 or 6, wherein, In step 1), the mixing is mechanical mixing, ball milling or mixing in the form of slurry; and / or In step 2), the granulation treatment is disc rolling granulation, spray granulation, compression molding or sol-gel method; and / or In step 2), the amount of water added is 10%-100% of the solid mass; and / or In step 2), the particle size range of the primary screening is 0.3-5 mm; and / or In step 3), the drying conditions are: drying in an oven at 90-300 ℃ for 4-24 h; and / or In step 3), the high-temperature heat treatment temperature is 1200-1600 ℃, and the time is 1-5 h; and / or In step 3), the high-temperature heat treatment device is a fluidized bed calcination furnace, a rotary kiln, a tunnel kiln or a shuttle kiln; and / or In step 4), the screening particle size range is 0.5-3 mm.

8. The method of claim 7, wherein, In step 3), the drying conditions are: temperature of 150°C, time of 12h; and / or In step 3), the high-temperature heat treatment temperature is 1600°C, time is 2h.

9. An iron-manganese-based oxygen carrier prepared by the method of any one of claims 5 to 8.

10. Use of the iron-manganese-based oxygen carrier of any one of claims 1 to 4 and 9 in a chemical looping combustion / gasification process.

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