Chemical looping gasification composite oxygen carrier and preparation method and application thereof

Abstract

The present application relates to the technical field of chemical looping gasification, and particularly relates to a chemical looping gasification composite oxygen carrier and a preparation method and application thereof.The method comprises the following steps: (1) drying and magnetic separation of waste incineration bottom ash, and then calcining and crushing the magnetic bottom ash obtained by magnetic separation to obtain a magnetic component; (2) mixing the magnetic component with pretreated copper ore to obtain a mixture; (3) mixing the mixture, cement and water to obtain a slurry; (4) standing the slurry, and then calcining and crushing.The method realizes resource utilization and harmless utilization of waste incineration bottom ash, and greatly reduces the preparation cost of the oxygen carrier.Through the cooperation of the magnetic component in the waste incineration bottom ash and the copper ore, the activity and oxygen carrying performance of the oxygen carrier are improved.

Description

Technical Field

[0001] This invention relates to the field of chemical chaining gasification technology, specifically to a chemical chaining gasification composite oxygen carrier, its preparation method, and its application. Background Technology

[0002] Chemical looping gasification (CLP) offers significant advantages over other thermal processes in CO2 emission reduction. A typical CLP process consists of two steps (reduction and oxidation) to form a redox cycle. The oxygen carrier is first placed in a low oxygen partial pressure (typically in an inert atmosphere, such as N2), then the fuel in the reactor is partially oxidized by lattice oxygen while the oxygen carrier is reduced, subsequently exposed to an oxidant for re-oxidation to replenish its lattice oxygen.

[0003] There are four main types of oxygen carriers: single metal oxides, mixed metal oxides, natural ores, and metal waste. Currently reported methods for synthesizing oxygen carriers typically involve very complex manufacturing processes and are costly to produce. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of poor dispersibility, compressive strength, high preparation cost and poor oxygen carrying performance of existing oxygen carriers, and to provide a chemically chained vaporization composite oxygen carrier, its preparation method and application.

[0005] To achieve the above objectives, a first aspect of the present invention provides a method for preparing a chemical looping gasification composite oxygen carrier using waste incineration bottom ash, the method comprising the following steps:

[0006] (1) Dry and magnetically separate the bottom ash from the waste incineration, and then calcine and crush the magnetic bottom ash obtained by magnetic separation to obtain magnetic components;

[0007] (2) The magnetic components are mixed with the pretreated copper ore to obtain a mixture;

[0008] (3) Mix the mixture, cement and water to obtain the slurry;

[0009] (4) Let the slurry stand, and then calcine and crush it.

[0010] Preferably, in step (1), the drying conditions include a temperature of 40-60°C and a time of 3-5 days.

[0011] Preferably, in step (1), the calcination conditions include: a temperature of 900-1100℃ and a time of 3-5h;

[0012] Preferably, the magnetic component has a particle size of 60-80 mesh.

[0013] Preferably, in step (2), the weight ratio of the pretreated copper ore to the magnetic component is 3:7-27.

[0014] Preferably, in step (2), the pretreatment step includes: roasting the copper ore at 400-600℃ for 5-6 hours, and then roasting it at 900-1100℃ for 8-12 hours;

[0015] Preferably, the copper ore has a particle size of 60-80 mesh.

[0016] Preferably, in step (3), the weight ratio of the mixture to cement is 3-4:1;

[0017] Preferably, the weight ratio of water to cement is 0.8-2:1.

[0018] Preferably, in step (4), the calcination process includes: calcining at 400-600°C for 2-3 hours, and then calcining at 900-1100°C for 5-8 hours;

[0019] Preferably, in step (5), the particles are crushed to a particle size of 40-60 mesh.

[0020] A second aspect of the present invention provides a chemically chained vaporization composite oxygen carrier prepared according to the method described above.

[0021] A third aspect of this invention provides the application of the aforementioned chemical looping gasification composite oxygen carrier in the chemical looping gasification process.

[0022] A fourth aspect of the present invention provides a method for preparing syngas using a chemical looping gasification reaction, comprising, for example, subjecting straw and an oxygen carrier to a chemical looping gasification reaction in the presence of a protective gas to obtain syngas;

[0023] The oxygen carrier is the chemically chained vaporization composite oxygen carrier described above;

[0024] Preferably, the conditions for the chemical looping gasification reaction include a temperature of 800-950°C.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. This invention provides a method for preparing chemical looping gasification composite oxygen carrier using waste incineration bottom ash. This method realizes the resource utilization and harmless utilization of waste incineration bottom ash, while greatly reducing the preparation cost of oxygen carrier.

[0027] 2. The chemically chained gasification composite oxygen carrier prepared by this invention has the advantages of high dispersibility and good compressive strength. At the same time, the activity and oxygen-carrying performance of the oxygen carrier are improved by combining the magnetic components in the bottom ash of waste incineration with copper ore. Detailed Implementation

[0028] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0029] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0030] The first aspect of this invention provides a method for preparing a chemical looping gasification composite oxygen carrier using waste incineration bottom ash, the method comprising the following steps:

[0031] (1) Dry and magnetically separate the bottom ash from the waste incineration, and then calcine and crush the magnetic bottom ash obtained by magnetic separation to obtain magnetic components;

[0032] (2) The magnetic components are mixed with the pretreated copper ore to obtain a mixture;

[0033] (3) Mix the mixture, cement and water to obtain the slurry;

[0034] (4) Let the slurry stand, and then calcine and crush it.

[0035] In this invention, the waste incineration bottom ash is the incineration residue of municipal solid waste.

[0036] In a preferred embodiment, the drying conditions in step (1) include: a temperature of 40-60°C and a time of 3-5 days; specifically, the drying temperature can be 40°C, 45°C, 50°C, 55°C or 60°C, and the drying time can be 3 days, 4 days or 5 days.

[0037] In a preferred embodiment, the calcination conditions in step (1) include: a temperature of 900-1100℃ and a time of 3-5 hours; specifically, the calcination temperature can be 900℃, 950℃, 1000℃, 1050℃, or 1100℃, and the calcination time can be 3 hours, 4 hours, or 5 hours. There are no special requirements for the calcination atmosphere; for example, it can be carried out in air.

[0038] In a preferred embodiment, in step (1), the particle size of the obtained magnetic component is controlled within the range of 60-80 mesh by crushing, which is beneficial to increasing the surface area to release the lattice oxygen of the component, and also beneficial to the subsequent preparation of the composite oxygen carrier.

[0039] In the method described in this invention, in step (1), the magnetic components in the waste incineration bottom ash can be separated by magnetic separation. The extracted magnetic components typically contain a large amount of iron oxide and a small amount of other transition metals (such as nickel, copper, manganese, and cobalt). There are no special requirements for the magnetic separation method, and it can be implemented in a manner conventional in the art. For example, magnetic rods can be used to separate the magnetic bottom ash from the waste incineration bottom ash.

[0040] In this invention, the addition of copper ore can effectively promote the reactivity of the oxygen carrier. To further improve the activity and oxygen-carrying performance of the composite oxygen carrier, the amounts of magnetic components and copper ore can be rationally controlled. In a preferred embodiment, in step (2), the weight ratio of pretreated copper ore to magnetic components is 3:7-27; specifically, it can be 3:7, 3:8, 3:9, 3:10, 3:12, 3:14, 3:15, 3:16, 3:18, 3:21, 3:24, or 3:27.

[0041] In a preferred embodiment, step (2) includes pretreatment: roasting the copper ore at 400-600℃ for 5-6 hours, and then roasting it at 900-1100℃ for 8-12 hours. The roasting process can be carried out in a muffle furnace.

[0042] In this invention, there are no special requirements regarding the source of the copper ore; it can be a commercially available product commonly used in the art. The copper ore contains CuO, CuFe2O4, and unavoidable impurities, which do not negatively impact the invention. In a preferred embodiment, the copper ore contains ≥20% by weight of CuO and ≥70% by weight of CuFe2O4. More preferably, the copper ore contains 20-28% by weight of CuO and 70-78% by weight of CuFe2O4.

[0043] In a preferred embodiment, the copper ore has a particle size of 60-80 mesh.

[0044] In this invention, by mixing cement, admixture and water, with cement acting as a binder to combine copper ore and magnetic components to form a composite oxygen carrier slurry, then allowing it to harden, and then calcining and crushing, a chemically chained gasification composite oxygen carrier can be obtained.

[0045] In a preferred embodiment, in step (3), the weight ratio of the mixture to cement is 3-4:1; specifically, it can be 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1 or 4:1.

[0046] In a preferred embodiment, the weight ratio of water to cement is 0.8-2:1; specifically, it can be 0.8:1, 1:1, 1.2:1, 1.5:1, 1.8:1, or 2:1.

[0047] In a preferred embodiment, step (4) includes calcining at 400-600°C for 2-3 hours, and then calcining at 900-1100°C for 5-8 hours.

[0048] In a preferred embodiment, in step (5), the calcined material is crushed to a particle size of 40-60 mesh to obtain a chemical chain gasification composite oxygen carrier.

[0049] A second aspect of the present invention provides a chemically chained vaporization composite oxygen carrier prepared according to the method described above.

[0050] A third aspect of this invention provides the application of the aforementioned chemical looping gasification composite oxygen carrier in the chemical looping gasification process.

[0051] The fourth aspect of the present invention provides a method for preparing syngas using a chemical looping gasification reaction, comprising: subjecting straw and an oxygen carrier to a chemical looping gasification reaction in the presence of a protective gas to obtain syngas;

[0052] The oxygen carrier is the chemically chained vaporization composite oxygen carrier as described in claim 8.

[0053] In a preferred embodiment, the conditions for the chemical looping gasification reaction include a temperature of 800-950°C; specifically, the temperature of the chemical looping gasification reaction can be 800°C, 820°C, 850°C, 960°C, 980°C, 900°C, 920°C, or 950°C.

[0054] Preferably, the weight ratio of straw to oxygen carrier can be 1:0.5-1.5.

[0055] In this invention, the protective gas can be nitrogen.

[0056] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0057] In the following examples and comparative examples, the waste incineration bottom ash used was all from municipal solid waste incineration plants, and the copper ore was purchased from a copper mining company in Jiangxi Province. The copper ore contained 23% CuO by weight and 71.6% CuFe2O4 by weight.

[0058] Example 1

[0059] (1) Dry the bottom ash of the waste incineration at 40℃ for 5 days, separate the magnetic bottom ash from the dried waste incineration bottom ash with a magnetic rod, then calcine the magnetic bottom ash in a muffle furnace at 900℃ for 5 hours, and then grind it to a particle size of 60-80 mesh to obtain the magnetic component.

[0060] (2) The copper ore with a particle size of 60-80 mesh is first roasted at 400℃ for 6 hours, and then roasted at 900℃ for 12 hours to remove impurity elements and obtain pretreated copper ore.

[0061] The pretreated copper ore and magnetic components were mixed at a weight ratio of 3:27 to obtain a mixture.

[0062] (3) Mix the mixture and cement at a weight ratio of 4:1, then add deionized water of equal weight to the cement and stir thoroughly to obtain the slurry;

[0063] (4) The slurry was left to harden naturally at room temperature (25℃) for 15 days, then calcined at 500℃ for 2 hours, and then calcined at 900℃ for 8 hours. The calcined material was then crushed to a particle size of 40-60 mesh to obtain chemical chain gasification composite oxygen carrier S1.

[0064] Example 2

[0065] (1) Dry the bottom ash of the waste incineration at 60℃ for 3 days, separate the magnetic bottom ash from the dried waste incineration bottom ash with a magnetic rod, then calcine the magnetic bottom ash in a muffle furnace at 1100℃ for 3 hours, and then grind it to a particle size of 60-80 mesh to obtain the magnetic component.

[0066] (2) The copper ore with a particle size of 60-80 mesh is first roasted at 600℃ for 5 hours, and then roasted at 1100℃ for 8 hours to remove impurity elements and obtain pretreated copper ore.

[0067] The pretreated copper ore and magnetic components were mixed at a weight ratio of 3:7 to obtain a mixture.

[0068] (3) Mix the mixture with cement at a weight ratio of 3:1, then add deionized water of equal weight to the cement and stir thoroughly to obtain the slurry;

[0069] (4) The slurry was left to harden naturally at room temperature (25℃) for 10 days, then calcined at 500℃ for 3 hours, and then calcined at 1100℃ for 5 hours. The calcined material was then crushed to a particle size of 40-60 mesh to obtain chemical chain gasification composite oxygen carrier S2.

[0070] Example 3

[0071] (1) Dry the bottom ash of the waste incineration at 50℃ for 4 days, separate the magnetic bottom ash from the dried waste incineration bottom ash with a magnetic rod, then calcine the magnetic bottom ash in a muffle furnace at 1000℃ for 4 hours, and then grind it to a particle size of 60-80 mesh to obtain the magnetic component.

[0072] (2) The copper ore with a particle size of 60-80 mesh is first roasted at 500℃ for 5h, and then roasted at 1000℃ for 7h to remove impurity elements to obtain the pretreated copper ore.

[0073] The pretreated copper ore was mixed with the magnetic component at a weight ratio of 3:12.

[0074] (3) Mix the mixture and cement at a weight ratio of 3.5:1, then add deionized water of equal weight to the cement and stir thoroughly to obtain the slurry;

[0075] (4) The slurry was left to harden naturally at room temperature (25℃) for 12 days, then calcined at 500℃ for 2.5h and then calcined at 1000℃ for 7h. The calcined material was then crushed to a particle size of 40-60 mesh to obtain chemical chain gasification composite oxygen carrier S3.

[0076] Example 4

[0077] (1) Dry the bottom ash of the waste incineration at 40℃ for 4 days, separate the magnetic bottom ash from the dried waste incineration bottom ash with a magnetic rod, then calcine the magnetic bottom ash in a muffle furnace at 1100℃ for 4 hours, and then grind it to a particle size of 60-80 mesh to obtain the magnetic component.

[0078] (2) The copper ore with a particle size of 60-80 mesh is first roasted at 400℃ for 6 hours, and then roasted at 1100℃ for 7 hours to remove impurity elements and obtain pretreated copper ore.

[0079] The pretreated copper ore and magnetic components were mixed at a weight ratio of 3:12 to obtain a mixture.

[0080] (3) Mix the mixture with cement at a weight ratio of 4:1, then add deionized water of equal weight to the cement and stir thoroughly to obtain the slurry;

[0081] (4) The slurry was left to harden naturally at room temperature (25℃) for 14 days, then calcined at 500℃ for 3 hours, and then calcined at 1100℃ for 7 hours. The calcined material was then crushed to a particle size of 40-60 mesh to obtain chemical chain gasification composite oxygen carrier S4.

[0082] Comparative Example 1

[0083] (1) Dry the bottom ash of the waste incineration at 40℃ for 5 days, separate the magnetic bottom ash from the dried waste incineration bottom ash with a magnetic rod, then calcine the magnetic bottom ash in a muffle furnace at 900℃ for 5 hours, and then grind it to a particle size of 60-80 mesh to obtain the magnetic component.

[0084] (2) Mix the magnetic components and cement at a weight ratio of 4:1, then add deionized water of equal weight to the cement and stir thoroughly to obtain the slurry.

[0085] (3) The slurry was left to harden naturally at room temperature (25℃) for 15 days, then calcined at 500℃ for 2 hours, and then calcined at 900℃ for 8 hours. The calcined material was then crushed to a particle size of 40-60 mesh to obtain chemical chain gasification composite oxygen carrier D1.

[0086] Test case

[0087] The performance of the oxygen carriers prepared in the examples and comparative examples was tested. The testing procedure was as follows: In the presence of nitrogen, straw and the test sample were subjected to a chemical looping gasification reaction at 850°C at a weight ratio of 1:1 to obtain syngas. The syngas was then passed into a flue gas analyzer to test its calorific value, and the results are shown in Table 1.

[0088] Table 1

[0089] <![CDATA[Calorific value of syngas (MJ / m 3 )]]> Example 1 13.63 Example 2 12.88 Example 3 10.32 Example 4 10.96 Comparative Example 1 6.58

[0090] As shown in Table 1, the chemically chained gasification composite oxygen carrier prepared by the method described in this invention can be used in the preparation of syngas and can produce syngas with a high calorific value.

[0091] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a chemical looping gasification composite oxygen carrier using waste incineration bottom ash, characterized in that, The method includes the following steps: (1) Dry and magnetically separate the bottom ash from the waste incineration, and then calcine and crush the magnetic bottom ash obtained by magnetic separation to obtain magnetic components; (2) The magnetic components are mixed with the pretreated copper ore to obtain a mixture; (3) Mix the mixture, cement and water to obtain the slurry; (4) Let the slurry stand, then calcine and crush it; In step (1), the particle size of the magnetic component is 60-80 mesh; In step (2), the weight ratio of the pretreated copper ore to the magnetic component is 3:7-27; The pretreatment steps include: roasting the copper ore at 400-600℃ for 5-6 hours, and then roasting it at 900-1100℃ for 8-12 hours; The copper ore has a particle size of 60-80 mesh; In step (3), the weight ratio of the mixture to cement is 3-4:1; In step (4), the calcination process includes: calcining at 400-600℃ for 2-3 hours, and then calcining at 900-1100℃ for 5-8 hours.

2. The method according to claim 1, characterized in that, In step (1), the drying conditions include a temperature of 40-60℃ and a time of 3-5 days.

3. The method according to claim 1 or 2, characterized in that, In step (1), the calcination conditions include a temperature of 900-1100℃ and a time of 3-5h.

4. The method according to claim 1, characterized in that, The weight ratio of water to cement is 0.8-2:

1.

5. The method according to claim 1, characterized in that, In step (4), the particles are crushed to a size of 40-60 mesh.

6. A chemically chained vaporization composite oxygen carrier prepared by the method according to any one of claims 1-5.

7. The application of the chemical looping gasification composite oxygen carrier as described in claim 6 in the chemical looping gasification process.

8. A method for preparing syngas using a chemical looping gasification reaction, characterized in that, include: In the presence of a protective gas, straw and oxygen carrier undergo a chemical looping gasification reaction to obtain syngas; The oxygen carrier is the chemically chained vaporization composite oxygen carrier as described in claim 6.

9. The method according to claim 8, characterized in that, The conditions for the chemical looping gasification reaction include a temperature of 800-950℃.