Oxycarbide for hydrogen production by chemical looping of low-quality coke breeze tail gas and closed calcium carbide furnace gas, and preparation method and application thereof

Abstract

The application discloses a low-quality semi-coke tail gas and closed calcium carbide furnace gas chemical chain hydrogen production oxygen carrier, a preparation method and application thereof, and has a chemical formula of A x B 1‑x Fe 12‑y Cu y O 19 , 0 < x < 1, 0 < y < 1, A is La or Y, and B is Sr or Ba. The preparation method comprises the following steps: adding precursors of La, Sr, Cu and Fe or adding precursors of Y, Ba, Cu and Fe into deionized water, uniformly mixing, obtaining a precursor solution, adding citric acid into the precursor solution, stirring until the citric acid is dissolved, adjusting the pH to 7-8, stirring under a heating condition until a viscous state is formed, drying, grinding, and calcining, so as to obtain the low-quality semi-coke tail gas and closed calcium carbide furnace gas chemical chain hydrogen production oxygen carrier. The oxygen carrier has the advantages of simple preparation method, environmental friendliness, easy industrial production, excellent redox reaction activity, high oxygen carrying capacity, hydrogen production capacity, hydrogen purity and cycle stability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of low-quality semi-coke tail gas and closed calcium carbide furnace gas chemical looping hydrogen production, and can provide a new way for low-carbon high-quality development of low-quality semi-coke tail gas and closed calcium carbide furnace gas, and can also provide a new way for resource utilization of coke oven gas, oilfield associated gas, coalbed methane and the like, and specifically relates to an oxygen carrier for low-quality semi-coke tail gas and closed calcium carbide furnace gas chemical looping hydrogen production and a preparation method and application thereof. BACKGROUND

[0002] The resource structure in China has the characteristics of more coal, less oil and lack of gas, and the rich coal reserves become the main aspect of the entire resource utilization. From the current energy distribution situation in China and the world, China is a large energy country dominated by coal. Coal, as an important energy and chemical raw material, accounts for more than 70% of primary energy consumption. This pattern will not change greatly in the future of China's energy and coal chemical industry. Semi-coke, also known as semi-coke, is a solid material with high fixed carbon content produced by a medium-low temperature dry distillation process. Coal tar and semi-coke tail gas are simultaneously produced during the production of semi-coke. Semi-coke tail gas mainly consists of H2, CH4, CO and a large amount of N2, etc. Due to the high nitrogen content and many impurities, it has been difficult to process and utilize, and most semi-coke tail gas is only used for power generation, etc. The resource utilization of semi-coke tail gas (such as methanol production, natural gas production and ammonia synthesis, etc.) is mostly based on multi-stage separation and purification of components, and the energy consumption is very high.

[0003] Semi-coke tail gas chemical looping hydrogen production is a high-efficiency, low-cost and high-purity hydrogen production technology. This technology uses the circulation of oxygen carriers to produce hydrogen by chemical looping of semi-coke tail gas after hydrogen extraction. Not only can the high-content (about 21-28%) and difficult-to-purify CH4 and CO gas in the tail gas be used for power generation, but also the reduced oxygen carriers can be obtained. Since the production of hydrogen and semi-coke tail gas are not in the same reactor, the high energy consumption caused by multi-stage separation and purification of semi-coke tail gas can be avoided, and a cheap hydrogen source free of carbon pollution can be obtained without additional separation process. The obtained hydrogen not only effectively solves the resource utilization of semi-coke tail gas, but also provides a hydrogen source for the deep processing of another byproduct of semi-coke medium-low temperature dry distillation, coal tar, or is used as a chemical raw material or clean energy, realizing low-carbon and high-quality utilization of low-quality semi-coke tail gas. This technology is also suitable for closed calcium carbide furnace gas (rich in CO, also containing CH4 and H2) chemical looping hydrogen production.

[0004] Oxygen carrier is the key of low-quality coking tail gas and closed calcium carbide furnace gas chemical chain hydrogen production technology, which not only requires high activity but also high cycle stability. Therefore, developing oxygen carrier with high cycle stability, high redox activity, low price and environmental friendly is the key of low-quality coking tail gas and closed calcium carbide furnace gas chemical chain hydrogen production technology. Fe-based oxygen carrier is concerned because of its high oxygen capacity, low cost and environmental friendly. However, Fe2O3 particles gradually sinter in the reaction process, and the stability is poor. At present, the oxygen carrier has the problem of high oxygen capacity and high cycle stability. SUMMARY

[0005] In order to overcome the problems in the prior art, the purpose of the present application is to provide a low-quality coking tail gas and closed calcium carbide furnace gas chemical chain hydrogen production oxygen carrier, its preparation method and application, which has high reaction activity, high oxygen capacity, hydrogen production, hydrogen purity and cycle stability in multiple oxidation-reduction processes.

[0006] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0007] A low-quality coking tail gas and closed calcium carbide furnace gas chemical chain hydrogen production oxygen carrier, the chemical formula is A x B 1-x Fe 12- y Cu y O 19 , 0 < x < 1, 0 < y < 1, A is La or Y, and B is Sr or Ba.

[0008] Further, 0.2 ≤ x ≤ 0.6, 0.05 ≤ y ≤ 0.8.

[0009] Further, x = 0.2, 0.4 or 0.6, y = 0.05, 0.1, 0.2, 0.4, 0.6 or 0.8.

[0010] A preparation method of the oxygen carrier for hydrogen production by chemical looping of low-quality semicoke tail gas and closed calcium carbide furnace gas as described above, comprising the following steps: adding La, Sr, Cu and Fe precursors or adding Y, Ba, Cu and Fe precursors into deionized water, uniformly mixing to obtain a precursor solution, adding citric acid into the precursor solution, stirring to dissolve, adjusting pH to 7-8, then stirring under heating conditions to a viscous state, drying, grinding and calcining to obtain the oxygen carrier for hydrogen production by chemical looping of low-quality semicoke tail gas and closed calcium carbide furnace gas; wherein the amount of substance of citric acid is 1.5-2.5 times the total amount of substance of La, Sr, Cu and Fe, and the concentration of the La, Sr, Cu and Fe precursors in the precursor solution is 0.8-1.3 mol / L; the amount of substance of citric acid is 1.5-2.5 times the total amount of substance of Y, Ba, Cu and Fe, and the concentration of the Y, Ba, Cu and Fe precursors in the precursor solution is 0.8-1.3 mol / L.

[0011] A preparation method of the oxygen carrier for hydrogen production by chemical looping of low-quality semicoke tail gas and closed calcium carbide furnace gas as described above, comprising the following steps:

[0012] Adding La, Sr, Cu and Fe precursors or adding Y, Ba, Cu and Fe precursors into deionized water, uniformly mixing to obtain a precursor solution, adding saturated glycine solution and polyethylene glycol into the precursor solution, stirring to dissolve, drying, grinding and calcining to obtain the oxygen carrier for hydrogen production by chemical looping of low-quality semicoke tail gas and closed calcium carbide furnace gas; wherein the amount of substance of saturated glycine is 1.3-1.5 times the total amount of substance of La, Sr, Cu and Fe, the amount of substance of polyethylene glycol is 0.8-1.2 times the amount of substance of saturated glycine, and the concentration of the La, Sr, Cu and Fe precursors in the precursor solution is 0.8-1.3 mol / L; the amount of substance of saturated glycine is 1.3-1.5 times the total amount of substance of Y, Ba, Cu and Fe, the amount of substance of polyethylene glycol is 0.8-1.2 times the amount of substance of saturated glycine, and the concentration of the Y, Ba, Cu and Fe precursors in the precursor solution is 0.8-1.3 mol / L.

[0013] A preparation method of the oxygen carrier for hydrogen production by chemical looping of low-quality semicoke tail gas and closed calcium carbide furnace gas as described above, comprising the following steps:

[0014] Adding Cu precursor into deionized water, stirring and dissolving, then adding La x Sr 1-x Fe 12 O 19 powder or Y x Ba 1- x Fe 12 O19 The powder was added to a Cu precursor solution and stirred until homogeneous. Then, a saturated ammonium carbonate solution was added and mixed thoroughly. The mixture was filtered, dried, and the powder was obtained. The powder was then calcined to obtain a low-quality semi-coke tail gas and a closed-loop calcium carbide furnace gas chemical looping hydrogen production oxygen carrier. The amount of saturated ammonium carbonate was 1.3-1.5 times the total amount of La, Sr, Cu, and Fe, and the concentrations of the precursors La, Sr, Cu, and Fe in the precursor solution were all 0.8-1.3 mol / L. Similarly, the amount of saturated ammonium carbonate was 1.3-1.5 times the total amount of Y, Ba, Cu, and Fe, and the concentrations of the precursors Y, Ba, Cu, and Fe in the precursor solution were all 0.8-1.3 mol / L.

[0015] A method for preparing a hydrogen carrier for chemical looping hydrogen production from low-quality semi-coke tail gas and closed calcium carbide furnace gas as described above includes the following steps:

[0016] Add the precursors of La, Sr, Fe and Cu or Y, Ba, Cu and Fe to deionized water, mix well, and obtain a precursor solution.

[0017] Add the precursor solution to a saturated ammonium carbonate solution, mix well, adjust the pH to 8-10, stir at 60-70℃ for 5-6 hours, then age and stand for 1-2 hours, filter and dry, then calcine at 400-500℃ for 4-5 hours and calcinate at 800-1100℃ for 4-5 hours to obtain low-quality semi-coke tail gas and closed calcium carbide furnace gas chemical looping hydrogen production oxygen carrier.

[0018] The amount of saturated ammonium carbonate is 1.3-1.5 times the total amount of La, Sr, Cu and Fe, and the concentration of La, Sr, Cu and Fe precursors in the precursor solution is 0.8-1.3 mol / L; the amount of saturated ammonium carbonate is 1.3-1.5 times the total amount of Y, Ba, Cu and Fe, and the concentration of Y, Ba, Cu and Fe precursors in the precursor solution is 0.8-1.3 mol / L.

[0019] Application of a low-quality semi-coke tail gas and closed calcium carbide furnace gas as described above in chemical looping hydrogen production oxygen carrier in chemical looping reaction.

[0020] Furthermore, a connected fuel reactor and hydrogen production reactor are used, with the oxygen carrier circulating between them. In the fuel reactor, the oxygen carrier reacts with low-quality semi-coke tail gas and closed calcium carbide furnace gas at 600-1000℃ to produce CO2 and H2O. At the same time, the oxygen carrier is reduced by the reducing gas in the low-quality semi-coke tail gas or the reducing gas in the closed calcium carbide furnace gas. The reduced oxygen carrier is oxidized and regenerated in the hydrogen production reactor with water vapor at 600-1000℃, while producing H2.

[0021] Furthermore, the reducing gases in low-quality semi-coke tail gas and closed calcium carbide furnace gas include CH4, CO and H2.

[0022] Compared with the prior art, the present invention has the following beneficial technical effects:

[0023] The oxygen carrier of this invention is La x Sr 1-x Fe 12-y Cu y O 19 (0 < x < 1, 0 < y < 1) composite oxygen carrier, mainly composed of La co-substituted with magnetoplumule (MP) type La and Cu. x Sr 1-x Fe 12-y Cu y O 19 The structure consists of hexaferrate and Fe2O3 crystal phases. The addition of La inhibits the formation of the SrFe2O5 crystal phase. Appropriate amounts of La increase the reactivity of the oxygen carrier with methane and the release rate of lattice oxygen. The addition of Cu significantly improves the reactivity with CH4 and CO, the migration and diffusion ability of lattice oxygen, and the oxygen release from the oxygen carrier. The ideal charge of the large cation in the MP-type hexaferrate structure is +2.4, while SrFe... 12 O 19 In the oxygen carrier, Sr ions are in the +2 valence state, lacking a portion of positive charge. Appropriate substitution of +2 valence Sr with +3 valence La reduces lattice defects in the MP-type structure through a charge compensation mechanism, enhancing the supporting effect of the large cation on the hexaferrate framework. The addition of Cu can reduce Fe... 3+ The activation energy during reduction promotes deep reduction of iron oxides, increasing the oxygen carrying capacity and resistance to carbon deposition of the oxygen carrier. The co-substitution of La and Cu helps maintain the high reactivity and high cycling stability of the oxygen carrier, resulting in high hydrogen production and purity. The oxygen carrier in this invention is Y. x Ba 1-x Fe 12-y Cu y O 19 The composite oxide oxygen carrier is mainly composed of magnetoplumbourine (MP) type Y and Cu co-substituted Y. x Ba 1-x Fe 12- y Cu y O 19 It consists of hexaferrate and Fe₂O₃ crystal phases. In Y 0.4 Ba 0.6 Fe 12-y Cu y O 19The Fe ions and Cu ions in the structure enter the ferrite lattice and are highly dispersed, and the spacing effect of the Y and Ba large cations inhibits the sintering and agglomeration of the Fe ions and Cu ions in the high-temperature reaction, thereby improving the cycle stability of the oxygen carrier. 0.4 Ba 0.6 Fe 12-y Cu y O 19 The synergistic effect of Y and Fe2O3 is beneficial to the conversion of the most difficult-to-convert methane in the semi-coke tail gas and the closed calcium carbide furnace gas, and the improvement of the oxygen carrying capacity, hydrogen production capacity and cycle stability.

[0024] The preparation method of the present application is simple, environmentally friendly and easy to industrialize. The preparation method can use co-precipitation, sol-gel, combustion, impregnation-precipitation and other methods, and the precursor can select a variety of precursors.

[0025] Further, the present application uses strontium nitrate, lanthanum nitrate, iron nitrate and copper nitrate as precursors, prepares the corresponding precursor solution, mixes the precursor solution, uses ammonium carbonate solution as a precipitant, adjusts the pH with ammonia water, then co-precipitates, and then filters, dries and calcines to obtain a composite oxide oxygen carrier.

[0026] The La x Sr 1-x Fe 12-y Cu y O 19 and Y 0.4 Ba 0.6 Fe 12-y Cu y O 19 The composite oxygen carrier can withstand the high temperature of 600-1000 DEG C in the fuel reactor and hydrogen production reactor without deactivation, has excellent impact mechanical properties and high temperature stability. In 10 cycles of reaction, the methane conversion rate is as high as 94-100%, the carbon dioxide selectivity is 100%, the oxygen output is as high as 2.60 mmol / g, the CO conversion rate is as high as 99% or more, the hydrogen production capacity is as high as 58.6 mL / g, the hydrogen purity is 99.993%, and the oxidation-reduction activity, oxygen carrying capacity, hydrogen production capacity, hydrogen purity and cycle stability are very excellent. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The X-ray powder diffraction spectrum of the oxygen carrier prepared in the present application Comparative Example 1.

[0028] Figure 2 X-ray powder diffraction pattern of the oxygen carrier prepared in Comparative Example 2 of the present invention.

[0029] Figure 3 X-ray powder diffraction pattern of the oxygen carriers prepared in Comparative Example 2 and Examples 1-4 of the present invention.

[0030] Figure 4 X-ray powder diffraction pattern of the SrFe 12 O 19 Kinetics plot of the reactivity of the oxygen carrier with methane.

[0031] Figure 5 X-ray powder diffraction pattern of the La 0.2 Sr 0.8 Fe 12 O 19 Kinetics plot of the reactivity of the oxygen carrier with methane.

[0032] Figure 6 X-ray powder diffraction pattern of the La 0.2 Sr 0.8 Fe 11.8 Cu 0.2 O 19 Kinetics plot of the reactivity of the oxygen carrier with methane.

[0033] Figure 7 Comparison plot of the methane conversion during 10 cycles of reaction of the oxygen carriers prepared in Comparative Example 2 and Examples 1, 3 of the present invention.

[0034] Figure 8 Comparison plot of the oxygen evolution during 10 cycles of reaction of the oxygen carriers prepared in Comparative Example 2 and Examples 1, 3 of the present invention.

[0035] Figure 9 Comparison plot of the carbon dioxide selectivity during 10 cycles of reaction of the oxygen carriers prepared in Comparative Example 2 and Examples 1, 3 of the present invention.

[0036] Figure 10 Comparison plot of the methane conversion during 10 cycles of reaction of the oxygen carriers prepared in Examples 3, 7, 8 of the present invention.

[0037] Figure 11 X-ray powder diffraction pattern of the La 0.2 Sr 0.8 Fe 12 O 19 Kinetics plot of the reactivity of the oxygen carrier with CO.

[0038] Figure 12La prepared in Example 1 of the present invention 0.2 Sr 0.8 Fe 11.95 Cu 0.05 O 19 Kinetics of oxygen carrier reactivity with CO.

[0039] Figure 13 Concentration of hydrogen gas produced by reaction of the oxygen carriers prepared in Comparative Example 1, Comparative Example 2, and Example 3 of the present invention with steam after reduction.

[0040] Figure 14 Comparison of hydrogen production during 10 cycles of reaction of the oxygen carriers prepared in Comparative Example 1, Comparative Example 2, and Example 3 of the present invention.

[0041] Figure 15 Comparison of hydrogen purity during 10 cycles of reaction of the oxygen carriers prepared in Comparative Example 1, Comparative Example 2, and Example 3 of the present invention.

[0042] Figure 16 X-ray powder diffraction patterns of the oxygen carriers prepared in Comparative Examples 6-9 of the present invention.

[0043] Figure 17 X-ray powder diffraction patterns of the oxygen carriers prepared in Examples 22-25 of the present invention.

[0044] Figure 18 Comparison of methane conversion during 10 cycles of reaction of the oxygen carriers prepared in Comparative Examples 6-9, Example 24, and Example 25 of the present invention.

[0045] Figure 19 Comparison of oxygen production during 10 cycles of reaction of the oxygen carriers prepared in Comparative Examples 6-9, Example 24, and Example 25 of the present invention.

[0046] Figure 20 Kinetics of steam reactivity of the oxygen carriers prepared in Comparative Examples 6-9, Example 24, and Example 25 of the present invention.

[0047] Figure 21 Comparison of hydrogen production by steam reactivity of the oxygen carriers prepared in Comparative Examples 6-9, Example 24, and Example 25 of the present invention.

[0048] Figure 22 Comparison of hydrogen purity by steam reactivity of the oxygen carriers prepared in Comparative Examples 6-9, Example 24, and Example 25 of the present invention.

[0049] Figure 23 Comparison of hydrogen production during 10 cycles of reaction of the oxygen carriers prepared in Comparative Example 8, Comparative Example 9, Example 24, and Example 25 of the present invention.

[0050] Figure 24 This is a comparison chart of hydrogen purity after 10 cycles of reaction of the oxygen carriers prepared in Comparative Examples 8, 9, 24, and 25 of this invention.

[0051] Figure 25 This is a comparison chart of the steam oxygen supply of the oxygen carriers prepared in Comparative Examples 8, 9, 24, and 25 of this invention for 10 cycles. Detailed Implementation

[0052] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments, but the present invention is not limited to the following examples.

[0053] The oxygen carrier for the chemical looping hydrogen production from low-quality semi-coke tail gas and closed calcium carbide furnace gas of the present invention is A. x B 1-x Fe 12- y Cu y O 19 , 0 < x < 1, 0 < y < 1, A is La or Y, B is Sr or Ba.

[0054] For La x Sr 1-x Fe 12-y Cu y O 19 Preferably, 0.2 ≤ x ≤ 0.6, 0.05 ≤ y ≤ 0.4; more preferably, x = 0.2, 0.4, or 0.6, y = 0.05, 0.1, 0.2, or 0.4, where La partially replaces SrFe. 12 O 19 Sr and Cu partially replace SrFe 12 O 19 The co-substitution of Fe, La and Cu in the oxygen carrier is beneficial to maintaining the high reactivity and high cycling stability of the oxygen carrier, and to obtaining high hydrogen production and hydrogen purity.

[0055] For Y x Ba 1-x Fe 12-y Cu y O 19 Preferably, 0 < x < 0.5, 0 < y < 1, and preferably, x = 0.4, y = 0.2, 0.4, 0.6, and 0.8, where Cu partially replaces Y. 0.4 Ba 0.6 Fe 12 O 19 Fe in it.

[0056] The preparation method of the oxygen carrier for hydrogen production by chemical looping of low-quality semi-coke tail gas and closed calcium carbide furnace gas is one of a co-precipitation method, a sol-gel method, a combustion method, or an impregnation and precipitation method.

[0057] The oxygen carrier is prepared by a co-precipitation method: La, Sr, Fe, and Cu precursors or Y, Ba, Cu, and Fe precursors are added to heated deionized water, mixed uniformly to obtain a precursor solution, the precursor solution is added to a saturated ammonium carbonate solution, mixed uniformly, the pH is adjusted to 8-10, and rapid stirring is performed for 5-6 h under the condition of maintaining a constant temperature of 60-70 ℃. After stirring is completed, the water bath is removed, and the sample is aged and placed at room temperature for 1-2 h, then filtered, washed with distilled water for 3-5 times, and placed in a drying box for drying at a constant temperature of 100-120 ℃ for 10-12 h. Then, the dried sample is taken out, ground into a powder, placed in a muffle furnace, heated from room temperature to 400-500 ℃ at a heating rate of 3-5 ℃ / min, calcined at 800-1100 ℃ at a heating rate of 3-5 ℃ / min for 4-5 h, and then cooled to room temperature to obtain the oxygen carrier for hydrogen production by chemical looping of low-quality semi-coke tail gas and closed calcium carbide furnace gas.

[0058] The molar amount of the saturated ammonium carbonate is 1.3-1.5 times the total molar amount of La, Sr, Fe, and Cu; and the molar amount of the saturated ammonium carbonate is 1.3-1.5 times the total molar amount of Y, Ba, Cu, and Fe.

[0059] The precursor of La is La(NO3)3;

[0060] The precursor of Sr is at least one of Sr(NO3)2, SrCO3, and SrO;

[0061] The precursor of Fe is at least one of FeCl3·6H2O, Fe(NO3)3·9H2O, and Fe2(SO4)3·9H2O;

[0062] The precursor of Cu is Cu(NO3)2;

[0063] The precursor of Ba is at least one of Ba(NO3)2 and Ba(CH3COO)2;

[0064] The precursor of Y is Y(NO3)3·6H2O.

[0065] The concentration of the precursors of La, Sr, Fe, and Cu in the precursor solution is 0.8-1.3 mol / L.

[0066] The concentration of the precursors of Y, Ba, Cu, and Fe in the precursor solution is 0.8-1.3 mol / L.

[0067] The sol-gel method is as follows: La, Sr, Cu and Fe precursors or Y, Ba, Cu and Fe precursors are added into deionized water and uniformly mixed to obtain a precursor solution, citric acid is added into the precursor solution and stirred until dissolved, the pH is adjusted to 7-8, and then the mixture is stirred to a viscous state under heating, and dried, ground and calcined to obtain the low-quality low-temperature carbon tail gas and closed calcium carbide furnace gas chemical looping hydrogen oxygen carrier; wherein the amount of substance of the citric acid is 1.5-2.5 times the total amount of substance of La, Sr, Cu and Fe, and the concentration of the La, Sr, Cu and Fe precursors in the precursor solution is 0.8-1.3 mol / L; the amount of substance of the citric acid is 1.5-2.5 times the total amount of substance of Y, Ba, Cu and Fe, and the concentration of the Y, Ba, Cu and Fe precursors in the precursor solution is 0.8-1.3 mol / L.

[0068] The combustion method is as follows: La, Sr, Cu and Fe precursors or Y, Ba, Cu and Fe precursors are added into deionized water and uniformly mixed to obtain a precursor solution, saturated glycine solution and polyethylene glycol are sequentially added into the precursor solution and stirred until dissolved, and then dried, ground and calcined to obtain the low-quality low-temperature carbon tail gas and closed calcium carbide furnace gas chemical looping hydrogen oxygen carrier; wherein the amount of substance of the saturated glycine is 1.3-1.5 times the total amount of substance of La, Sr, Cu and Fe, the amount of substance of the polyethylene glycol is 0.8-1.2 times the amount of substance of the saturated glycine, and the concentration of the La, Sr, Cu and Fe precursors in the precursor solution is 0.8-1.3 mol / L; the amount of substance of the saturated glycine is 1.3-1.5 times the total amount of substance of Y, Ba, Cu and Fe, the amount of substance of the polyethylene glycol is 0.8-1.2 times the amount of substance of the saturated glycine, and the concentration of the Y, Ba, Cu and Fe precursors in the precursor solution is 0.8-1.3 mol / L.

[0069] The impregnation precipitation method is as follows: La x Sr 1-x Fe 12 O 19 and Y x Ba 1-x Fe 12 O 19 are prepared by the coprecipitation method, Cu precursors are added into deionized water and stirred and dissolved, and then La x Sr 1-x Fe 12 O 19 powder or Y x Ba 1-x Fe 12 O 19The powder is added into a precursor solution of Cu, stirred uniformly, then saturated ammonium carbonate solution is added and stirred uniformly, filtered, dried to obtain the powder, and the powder is calcined to obtain the low-quality coking tail gas and the closed calcium carbide furnace gas chemical looping hydrogen oxygen carrier.

[0070] The preparation method of the application is simple, environmentally friendly and easy to industrialize.

[0071] The La x Sr 1-x Fe 12-y Cu y O 19 oxygen carrier or Y x Ba 1-x Fe 12-y Cu y O 19 application of the oxygen carrier in chemical looping hydrogen production, wherein two interconnected reactors are used, and the oxygen carrier circulates between a fuel reactor and a hydrogen production reactor; in the fuel reactor, the oxygen carrier oxidizes the reducing gas in the coking tail gas or the closed calcium carbide furnace gas with its own lattice oxygen, and at the same time, the oxygen carrier is reduced, the reaction temperature is 600-1000 DEG C, and the reaction pressure is normal pressure; the reduced oxygen carrier is regenerated with steam in the hydrogen production reactor at 600-1000 DEG C to produce H2, and high-purity hydrogen can be obtained by condensing H2O, and the reaction pressure is normal pressure.

[0072] When steam is introduced for oxidation, the oxygen carrier is partially oxidized, and then air or oxygen is introduced to completely oxidize and regenerate the oxygen carrier to complete one cycle, then inert gas is introduced for purging, and then fuel gas is introduced, and the above steps are sequentially repeated for multiple cycles.

[0073] In the fuel reactor, the oxygen carrier reacts with the reducing gas methane to generate CO2 and H2O, or reacts with CO to generate CO2, and in 10 cycles, the methane conversion rate is still above 96%, and the carbon dioxide selectivity is 100%; the reduced oxygen carrier can be regenerated with steam in the hydrogen production reactor to obtain high-purity hydrogen without carbon pollution; and the oxygen carrier has very excellent redox activity, high oxygen carrying capacity, hydrogen production capacity, hydrogen purity and cycle stability in the chemical looping hydrogen production reaction.

[0074] Comparative Example 1

[0075] Preparation of SrFe 12 O 19 (x = 0, y = 0) composite oxygen carrier. The steps are as follows:

[0076] In deionized water at a temperature of 60°C, Sr(NO3)2 and Fe(NO3)3·9H2O were added in a molar ratio of 1:12 to prepare a mixed solution with a concentration of 1 mol / L, and stirred for 10 min to obtain a precursor solution.

[0077] Then the precipitant was prepared. In deionized water at a temperature of 60°C, ammonium carbonate was added (the amount of ammonium carbonate was 1.3 times the theoretical value) to prepare a (NH4)2CO3 solution with a concentration of 1 mol / L.

[0078] After that, the uniformly stirred precursor solution was quickly added to the (NH4)2CO3 solution, the amount of substance of ammonium carbonate was 1.3 times the total amount of substance of Sr and Fe, and the pH was adjusted to 8-10, and the stirring was kept at a constant temperature of 60°C for 6 h. After the stirring was completed, the water bath was removed, and the sample was aged and placed at room temperature for 1 h, then filtered, washed with distilled water 3 times, and placed in a forced air drying oven at a constant temperature of 120°C for 12 h. After that, the dried sample was taken out and ground into powder, and placed in a muffle furnace, heated to 500°C at a rate of 5°C / min and kept for 4 h, and then heated to 900°C at a rate of 5°C / min and calcined for 4 h.

[0079] Oxygen carrier SrFe 12 O 19 The powder X-ray diffraction test was performed on an X'pert Pro Super ray diffractometer of PANalytical Company in the Netherlands. The copper target Kα line was used as the light source (λ = 0.15432 nm), the graphite monochromator, the tube voltage was 40 kV, and the tube current was 40 mA. The X-ray diffraction test results are shown in Figure 1 .

[0080] From Figure 1 it can be seen that the SrFe 12 O 19 oxygen carrier mainly presents MP type hexaferrite crystal phase, accompanied by a small amount of Fe2O3 and SrFe2O5 phase.

[0081] Comparative Example 2

[0082] Preparation of La 0.2 Sr 0.8 Fe 12 O 19(x = 0.2, y = 0) composite oxygen carrier. The steps are as follows:

[0083] La(NO3)3·6H2O, Sr(NO3)2 and Fe(NO3)3·9H2O were added in a molar ratio of 1:4:60 to prepare a mixed solution with a concentration of 1 mol / L, and stirred for 10 min to obtain a precursor solution.

[0084] Then, the precipitant was prepared. Ammonium carbonate was added to deionized water at 60°C to prepare a (NH4)2CO3 solution with a concentration of 1 mol / L, and the amount of ammonium carbonate was 1.3 times the theoretical value.

[0085] Then, the uniformly stirred precursor solution was quickly added to the (NH4)2CO3 solution, and the amount of ammonium carbonate was 1.3 times the total amount of La, Sr and Fe, and the pH was adjusted to 8-10. The solution was stirred rapidly for 6 h while maintaining a constant temperature of 60°C. After stirring, the water bath was removed and the solution was aged at room temperature for 1 h. Then, the solution was filtered and washed with distilled water three times. The sample was placed in a forced air drying oven and dried at a constant temperature of 120°C for 12 h. Then, the dried sample was taken out and ground into powder, and then placed in a muffle furnace. The temperature was raised to 500°C at a rate of 5°C / min and maintained for 4 h, and then the temperature was raised to 900°C at a rate of 5°C / min and calcined for 4 h.

[0086] The oxygen carrier prepared in Comparative Example 2 was La 0.2 Sr 0.8 Fe 12 O 19 The powder X-ray diffraction test was performed on an X'pert Pro Super ray diffractometer of PANalytical Company in the Netherlands. The copper target Kα line was used as the light source (λ = 0.15432 nm), a graphite monochromator, the tube voltage was 40 kV, and the tube current was 40 mA. The X-ray diffraction test results are shown in Figure 2 .

[0087] As can be seen from Figure 2 , the La 0.2 Sr 0.8 Fe 12 O 19 The oxygen carrier mainly presents the MP type hexaferrite crystal phase, accompanied by a small amount of Fe2O3 phase, and no SrFe2O5 crystal phase is observed, indicating that the addition of La inhibits the formation of the SrFe2O5 crystal phase. No La-containing phase is observed, and at the same time, the MP type hexaferrite diffraction peak shifts to a high angle, indicating that the small radius La 3+ successfully replaces the large radius Sr 2+Doping into the MP-type hexaferrite forms a La-substituted Sr-based hexaferrite.

[0088] Example 1

[0089] Preparation of La 0.2 Sr 0.8 Fe 11.95 Cu 0.05 O 19 (x = 0.2, y = 0.05) composite oxygen carrier. The steps are as follows:

[0090] La (NO3)3·6H2O, Cu (NO3)2, Sr (NO3)2and Fe (NO3)3·9H2O with a molar ratio of 4:1:16:239 were sequentially added in deionized water at a temperature of 60°C to obtain a mixed solution of La 3+ , Cu 2+ , Sr 2+ , Fe 3+ with a concentration of 1 mol / L, and stirred for 10 min to obtain a precursor solution.

[0091] Then the precipitant was prepared: (NH4)2CO3 solution with a concentration of 1 mol / L was prepared by adding ammonium carbonate in deionized water at a temperature of 60°C.

[0092] Then the precursor solution was quickly added to the (NH4)2CO3 solution, and the amount of substance of ammonium carbonate was 1.3 times the total amount of substance of La, Sr, Fe and Cu, and the pH was adjusted to 8-10. Under the condition of maintaining a constant temperature of 60°C, rapid stirring was carried out for 6 h. After stirring, the water bath was taken out and aged at room temperature for 1 h, then suction filtered, washed with distilled water for 3 times, and the sample was placed in a blast drying oven and dried at a constant temperature of 120°C for 12 h. Then, the dried sample was taken out and ground into powder, which was placed in a muffle furnace, heated to 500°C at a rate of 5°C / min and kept for 4 h, then heated to 900°C at a rate of 5°C / min and calcined for 4 h to obtain a low-quality coke tail gas and a closed calcium carbide furnace gas chemical looping hydrogen oxygen carrier.

[0093] Example 2

[0094] Preparation of La 0.2 Sr 0.8 Fe 11.9 Cu 0.1 O 19 (x = 0.2, y = 0.1) composite oxygen carrier. The steps are as follows:

[0095] The specific operation is the same as that in Example 1, except that the molar ratio of La(N03)3-6H20, Cu(N03)2, Sr(N03)2, and Fe(N03)3-9H20 in the precursor solution is 2:1:8:119.

[0096] Example 3

[0097] Preparation of La 0.2 Sr 0.8 Fe 11.8 Cu 0.2 O 19 (x = 0.2, y = 0.2) composite oxygen carrier. The steps are as follows:

[0098] The specific operation is the same as that in Example 1, except that the molar ratio of La(N03)3-6H20, Cu(N03)2, Sr(N03)2, and Fe(N03)3-9H20 in the precursor solution is 1:1:4:59.

[0099] Example 4

[0100] Preparation of La 0.2 Sr 0.8 Fe 11.6 Cu 0.4 O 19 (x = 0.2, y = 0.4) composite oxygen carrier. The steps are as follows:

[0101] The specific operation is the same as that in Example 1, except that the molar ratio of La(N03)3-6H20, Cu(N03)2, Sr(N03)2, and Fe(N03)3-9H20 in the precursor solution is 1:2:4:58.

[0102] X-ray diffraction test:

[0103] The powder X-ray diffraction test on the composite oxygen carriers La x Sr 1-x Fe 12-y Cu y O 19 (x = 0.2, y = 0.05, 0.1, 0.2, 0.4) prepared in Example 1, Example 2, Example 3, and Example 4 was performed on an Xpert Pro Super ray diffractometer of PANalytical Company in the Netherlands. The copper target K alpha line was the light source (λ = 0.15432 nm), the graphite monochromator, the tube voltage was 40 kV, and the tube current was 40 mA. The X-ray diffraction test results are shown in Figure 3

[0104] From Figure 3 ​It can be seen that the fresh oxygen carriers are all MP-type hexaferrate and Fe2O3 crystalline phases, with no other crystalline phases formed. Meanwhile, with increasing Cu substitution, the diffraction peaks of the MP-type hexaferrate shift to lower angles. Considering that no Cu diffraction peaks were observed and Cu… 2+ Ionic radius greater than Fe 3+ Ions, indicating Cu 2+ Ions successfully replaced Fe 3+ The ions enter the MP-type La-substituted Sr-based hexaferrate, forming the La- and Cu co-substituted MP-type La. x Sr 1-x Fe 12-y Cu y O 19 Hexaferrate crystal phase.

[0105] Comparative Example 3

[0106] SrFe prepared in Comparative Example 1 12 O 19 The cyclic stability evaluation of the oxygen carrier was conducted using an atmospheric pressure quartz fixed-bed reactor heated by an electric furnace. 0.45 g of 20-40 mesh oxygen carrier was used. The fuel gas was methane (5 vol% CH4, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After 11 minutes of reduction, the gas was switched to argon (99.99% Ar) at a flow rate of 50 mL / min and a temperature of 900 °C. The evaluation results are as follows: Figure 4 As shown.

[0107] from Figure 4 As can be seen from the above, the SrFe prepared in Comparative Example 1 of this invention... 12 O 19 Unreacted methane was observed in the oxygen carrier after 6 minutes of reaction, and CO and H2 were observed to be produced after 7 minutes. After 11 minutes of reaction, a large amount of unreacted methane was observed.

[0108] Comparative Example 4

[0109] La prepared in Comparative Example 2 0.2 Sr 0.8 Fe 12 O 19 The cyclic stability evaluation of the oxygen carrier was conducted using an atmospheric pressure quartz fixed-bed reactor heated by an electric furnace. 0.45 g of 20-40 mesh oxygen carrier was used. The fuel gas was methane (5 vol% CH4, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After 11 minutes of reduction, the gas was switched to argon (99.99% Ar) at a flow rate of 50 mL / min and a temperature of 900 °C. The evaluation results are as follows: Figure 5 As shown.

[0110] from Figure 5 As can be seen, compared with the oxygen carrier in Comparative Example 1, no unreacted methane, CO, or H2 was observed to be produced in the first 8 minutes after the reaction with La doping. The CO2 production was significantly increased, indicating that 100% of the converted methane was completely oxidized to CO2. La doping can significantly improve the reactivity of the oxygen carrier with methane and the release rate of lattice oxygen. Only after 10 minutes of reaction was the production of trace amounts of unreacted methane, CO, and H2 observed.

[0111] Example 5

[0112] La prepared in Example 3 0.2 Sr 0.8 Fe 11.8 Cu 0.2 O 19 The activity evaluation of the oxygen carrier was conducted in a fixed-bed quartz reactor under atmospheric pressure, heated by an electric furnace. 0.45 g of 20-40 mesh oxygen carrier was used. The fuel gas was methane (5 vol% CH4, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900℃, and the reaction pressure was atmospheric pressure. After 11 minutes of reduction, the gas was switched to argon (99.99% Ar) at a flow rate of 50 mL / min and a temperature of 900℃. The evaluation results are as follows: Figure 6 As shown.

[0113] from Figure 6 As can be seen, compared with the oxygen carrier in Comparative Example 2, the concentration of carbon dioxide increased rapidly in the first 2 minutes of the reaction, and when the reaction reached the 11th minute, no unreacted methane, CO, or H2 was observed to be produced. This indicates that the addition of Cu significantly improved the reactivity of methane and the migration and diffusion ability of lattice oxygen, thereby contributing to the increase of oxygen production and hydrogen production.

[0114] Example 6

[0115] The cyclic stability of the oxygen carriers prepared in Comparative Example 2, Example 1, and Example 3 was evaluated using an atmospheric pressure quartz fixed-bed reactor heated by an electric furnace. 0.45 g of each of the 20-40 mesh oxygen carriers prepared in Comparative Example 2, Example 1, and Example 3 was taken. In the fuel reactor, the fuel gas was methane (5 vol% CH4, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After reduction for 8 minutes, the gas was switched to argon (99.99% Ar) at a flow rate of 50 mL / min and a temperature of 900 °C. Then, oxygen (5 vol% O2, 95 vol% Ar) was introduced into the regeneration reactor at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After the oxygen carrier was fully oxidized, the gas was switched back to argon, and then the fuel gas was introduced again, with the reaction conditions consistent with the reduction reaction conditions described above. This cycle was repeated 10 times. The reactor outlet gas was analyzed online using a GAM-200 mass spectrometer. The results of methane conversion, oxygen production, and carbon dioxide selectivity evaluation are as follows: Figure 7 , Figure 8 and Figure 9 As shown.

[0116] from Figure 7 As can be seen from La 0.2 Sr 0.8 Fe 12 O 19 The methane conversion rate was 91% in the 10th test. When the Cu doping amount was 0.05 and 0.2, the methane conversion rate of the oxygen carrier increased to over 96% and 94%, respectively. It can be seen that the introduction of Cu greatly improved the methane reactivity.

[0117] from Figure 8 As can be seen from La 0.2 Sr 0.8 Fe 12 O 19 The oxygen output in the 10th test was 2.13 mmol / g. When the Cu doping amount was 0.05 and 0.2, the oxygen output of the oxygen carrier increased to more than 2.21-2.23 mmol / g, which shows that the introduction of Cu increased the oxygen output of the oxygen carrier.

[0118] from Figure 9 As can be seen, the selectivity of carbon dioxide is 100% when the Cu doping concentration is 0.05 and 0.2, respectively.

[0119] The oxygen carriers prepared in Examples 2 (y = 0.1) and 4 (y = 0.4) have similar performance to those prepared in Examples 1 (y = 0.05) and 3 (y = 0.2).

[0120] Example 7

[0121] Preparation of La0.4 Sr 0.6 Fe 11.8 Cu 0.2 O 19 (x = 0.4, y = 0.2) Composite oxygen carrier. The steps are as follows:

[0122] The specific operation is the same as in Example 1, except that the molar ratio of La(NO3)3·6H2O, Cu(NO3)2, Sr(NO3)2 and Fe(NO3)3·9H2O in the precursor solution is 2:1:3:59.

[0123] Example 8

[0124] Preparation of La 0.6 Sr 0.4 Fe 11.8 Cu 0.2 O 19 (x = 0.6, y = 0.2) Composite oxygen carrier. The steps are as follows:

[0125] The specific operation is the same as in Example 1, except that the molar ratio of La(NO3)3·6H2O, Cu(NO3)2, Sr(NO3)2 and Fe(NO3)3·9H2O in the precursor solution is 3:1:2:59.

[0126] Example 9

[0127] The cyclic stability of the oxygen carriers prepared in Examples 3, 7, and 8 was evaluated using an atmospheric pressure quartz fixed-bed reactor heated by an electric furnace. 0.45 g of each of the 20-40 mesh oxygen carriers prepared in Examples 3, 7, and 8 was taken. In the fuel reactor, the fuel gas was methane (5 vol% CH4, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After reduction for 8 minutes, the gas was switched to argon (99.99% Ar) at a flow rate of 50 mL / min and a temperature of 900 °C. Then, oxygen (5 vol% O2, 95 vol% Ar) was introduced into the regeneration reactor at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After the oxygen carrier was fully oxidized, the gas was switched back to argon, and then the fuel gas was introduced again, with the reaction conditions consistent with the reduction reaction conditions described above. This cycle was repeated 10 times. The reactor outlet gas was analyzed online using a GAM-200 mass spectrometer. The methane conversion rate evaluation results are as follows: Figure 10 As shown.

[0128] from Figure 10 As can be seen, the methane conversion rate decreases with the increase of La doping amount, which indicates that only the addition of an appropriate amount of La can improve the reaction performance of the oxygen carrier.

[0129] Comparative Example 5

[0130] La 0.2 Sr 0.8 Fe 12 O 19 The cyclic stability of the oxygen carrier was evaluated using a constant pressure quartz fixed bed reactor, and the heating method was electric furnace heating. 20-40 mesh oxygen carriers 0.45 g were taken. The fuel gas was carbon monoxide (5 vol% CO, 95 vol% Ar), the flow rate was 15 mL / min, the reaction temperature was 900°C, and the reaction pressure was constant pressure. After reduction for 55 minutes, switch to argon (99.99% Ar), the flow rate was 50 mL / min, the temperature was 900°C, and the evaluation results are shown in Figure 11

[0131] As can be seen from Figure 11 , with the progress of the reaction, La 0.2 Sr 0.8 Fe 12 O 19 The oxygen carrier began to have unreacted CO at the 50th minute.

[0132] Example 10

[0133] La 0.2 Sr 0.8 Fe 11.95 Cu 0.05 O 19 The activity evaluation of the oxygen carrier was carried out using a constant pressure quartz fixed bed reactor, and the heating method was electric furnace heating. 20-40 mesh oxygen carriers 0.45 g were taken. The fuel gas was carbon monoxide (5 vol% CO, 95 vol% Ar), the flow rate was 15 mL / min, the reaction temperature was 900°C, and the reaction pressure was constant pressure. After reduction for 63 minutes, switch to argon (99.99% Ar), the flow rate was 50 mL / min, the temperature was 900°C, and the evaluation results are shown in Figure 12

[0134] As can be seen from Figure 12 , compared with Comparative Example 2, the oxygen carrier doped with Cu did not observe unreacted CO in the first 50 minutes, even 55 minutes, i.e. CO was completely converted to CO2, which shows that the doping of Cu also significantly improves the reaction activity of the oxygen carrier with CO.

[0135] Example 11

[0136] ​​The activity of the oxygen carriers prepared in Comparative Examples 1, 2, and 3 was evaluated using a fixed-bed quartz reactor under atmospheric pressure, with electric furnace heating. 0.45 g of 20-40 mesh oxygen carrier was used. The fuel gas was methane (5 vol% CO, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After 20 minutes of reduction, the gas was switched to argon (99.99% Ar) at a flow rate of 50 mL / min, followed by steam at a flow rate of 15 mL / min and a temperature of 900 °C. The evaluation results are as follows: Figure 13 As shown.

[0137] from Figure 13 As can be seen, in the initial stage of water vapor oxidation, the hydrogen concentration rapidly increases to a peak value, and then gradually decreases after reaching the peak value. The oxygen carrier co-substituted by La and Cu exhibits the highest hydrogen concentration, indicating that the synergistic effect of La and Cu significantly improves the ability of the oxygen carrier to react with water vapor to produce hydrogen.

[0138] Example 12

[0139] The cyclic stability of the oxygen carriers prepared in Comparative Examples 1, 2, and 3 was evaluated using an atmospheric pressure quartz fixed-bed reactor heated by an electric furnace. 0.45 g of each of the 20-40 mesh oxygen carriers prepared in Comparative Examples 1, 2, and 3 was taken. In the fuel reactor, the fuel gas was methane (5 vol% CH4, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After 20 minutes of reduction, the gas was switched to argon (99.99% Ar) at a flow rate of 50 mL / min and a temperature of 900 °C. Then, water vapor (5 vol% H2O, 95 vol% Ar) was introduced into the regeneration reactor at a flow rate of 15 mL / min, a reaction temperature of 900 °C, and a reaction pressure of atmospheric pressure. When no hydrogen was generated, oxygen was introduced to fully oxidize the oxygen carrier, then the gas was switched back to argon, and then fuel gas was introduced again. The reaction conditions were the same as the reduction reaction conditions described above, and this cycle was repeated 10 times. The reactor outlet gas was analyzed online using a GAM-200 mass spectrometer. The results of hydrogen production and hydrogen purity evaluation are as follows: Figure 14 , Figure 15 As shown.

[0140] from Figure 14 It can be seen from SrFe 12 O 19 and La 0.2 Sr 0.8 Fe 12 O 19 The hydrogen production in the 10th iteration was 23.5 mL / g and 30.6 mL / g, while the La and Cu co-substituted La... 0.2 Sr 0.8 Fe11.8 Cu 0.2 O 19 The hydrogen production of the oxygen carrier is increased to 32.9 mL / g or more, and the hydrogen production is even as high as 58.6 mL / g in the first cycle.

[0141] From Figure 15 It can be seen that the La 0.2 Sr 0.8 Fe 11.8 Cu 0.2 O 19 The hydrogen purity of the oxygen carrier is as high as 99.993%, which shows that the La

[0142] Example 13

[0143] The oxygen carrier prepared in Example 2 is evaluated in the same way as in Example 12, except that water vapor (99 vol% H2O, 1 vol% Ar) is then introduced into the regeneration reactor.

[0144] Example 14

[0145] The oxygen carrier prepared in Example 1 is evaluated for activity using a fixed bed reactor. The amount of oxygen carrier used is 0.45 g, and the particle size is 20-40 mesh. The fuel gas composition is 5% CH4 / Ar, the flow rate is 15 mL / min, the reaction temperature is 800°C, the reaction time is 15 min, and the reaction pressure is atmospheric pressure.

[0146] Example 15

[0147] The oxygen carrier prepared in Example 3 is evaluated for activity using a fixed bed reactor. The amount of oxygen carrier used is 0.45 g, and the particle size is 20-40 mesh. The fuel gas composition is 5% CH4 / Ar, the flow rate is 15 mL / min, the reaction temperature is 950°C, the reaction time is 15 min, and the reaction pressure is atmospheric pressure.

[0148] Example 16

[0149] La 0.2 Sr 0.8 Fe 11.9 Cu 0.1 O 19 (x=0.2, y=0.1) composite oxygen carrier. The steps are as follows:

[0150] La(NO3)3·6H2O, Cu(NO3)2, Sr(NO3)2, and Fe(NO3)3·9H2O in a molar ratio of 2:1:8:119 are sequentially added in deionized water at a temperature of 60°C to obtain La 3+ ,Cu2+ , Sr 2+ , Fe 3+ The mixed solution with a concentration of 0.8 mol / L was stirred for 10 min to obtain a precursor solution.

[0151] Then, the precipitant was prepared: (NH4)2CO3 solution with a concentration of 1 mol / L was prepared by adding ammonium carbonate into deionized water at a temperature of 60°C.

[0152] Then, the uniformly stirred precursor solution was rapidly added into the (NH4)2CO3 solution, the amount of substance of ammonium carbonate was 1.3 times the total amount of substance of La, Sr, Fe and Cu, and the pH was adjusted to 8-10, and rapid stirring was performed for 6 h under the condition of maintaining a constant temperature of 60°C. After the stirring was completed, the water bath was removed, and the sample was aged and placed at room temperature for 1 h, and then suction filtration was performed, the sample was washed with distilled water for 3 times, and the sample was placed in a blast drying oven and dried at a constant temperature of 120°C for 12 h. Then, the dried sample was taken out and ground into powder, and then placed in a muffle furnace, and heated at a temperature increasing rate of 5°C / min from room temperature to 500°C and maintained for 4 h, and then heated at a temperature increasing rate of 5°C / min to 900°C and calcined for 4 h.

[0153] Example 17

[0154] La 0.2 Sr 0.8 Fe 11.6 Cu 0.4 O 19 (x=0.2, y=0.4) composite oxygen carrier. The steps are as follows:

[0155] La(NO3)3·6H2O, Cu(NO3)2, Sr(NO3)2 and Fe(NO3)3·9H2O with a molar ratio of 1:2:4:58 were sequentially added into deionized water at a temperature of 60°C to obtain a mixed solution with a concentration of 1.2 mol / L, and the mixed solution was stirred for 10 min to obtain a precursor solution. 3+ , Cu 2+ , Sr 2+ , Fe 3+ The mixed solution with a concentration of 1.2 mol / L was stirred for 10 min to obtain a precursor solution.

[0156] Then, the precipitant was prepared: (NH4)2CO3 solution with a concentration of 1 mol / L was prepared by adding ammonium carbonate into deionized water at a temperature of 60°C.

[0157] Afterwards, the well-stirred precursor solution was quickly added into the (NH4)2CO3 solution, the amount of substance of ammonium carbonate was 1.3 times of the total amount of substance of La, Sr, Fe, Cu, and the pH was adjusted to 8-10, under the condition of keeping the temperature at 60°C, the rapid stirring was carried out for 6h. After the stirring was completed, the water bath was taken out, and the sample was aged at room temperature for 1h, then suction filtration was carried out, the sample was washed with distilled water for 3 times, and the sample was placed in a blast drying oven and dried at 120°C for 12h. Afterwards, the dried sample was taken out and ground into powder, and then placed in a muffle furnace, and heated from room temperature to 500°C at a rate of 5°C / min, kept for 4h, and then heated to 900°C at a rate of 5°C / min and calcined for 4h.

[0158] Example 18

[0159] Preparation of La 0.4 Sr 0.6 Fe 11.8 Cu 0.2 O 19 (x=0.4, y=0.2) composite oxygen carrier. The steps are as follows:

[0160] In deionized water at a temperature of 60°C, La(NO3)3·6H2O, Cu(NO3)2, Sr(NO3)2 and Fe(NO3)3·9H2O were sequentially added in a molar ratio of 2:1:3:59 to obtain a mixed solution with a concentration of 1 mol / L of La 3+ , Cu 2+ , Sr 2+ , Fe 3+ , and the stirring was carried out for 10 min to obtain a precursor solution.

[0161] Then, the precipitant was prepared: in deionized water at a temperature of 60°C, ammonium carbonate was added to prepare a (NH4)2CO3 solution with a concentration of 1 mol / L.

[0162] Afterwards, the well-stirred precursor solution was quickly added into the (NH4)2CO3 solution, the amount of substance of ammonium carbonate was 1.3 times of the total amount of substance of La, Sr, Fe, Cu, and the pH was adjusted to 8-10, under the condition of keeping the temperature at 60°C, the rapid stirring was carried out for 6h. After the stirring was completed, the water bath was taken out, and the sample was aged at room temperature for 1h, then suction filtration was carried out, the sample was washed with distilled water for 3 times, and the sample was placed in a blast drying oven and dried at 120°C for 12h. Afterwards, the dried sample was taken out and ground into powder, and then placed in a muffle furnace, and heated from room temperature to 500°C at a rate of 5°C / min, kept for 4h, and then heated to 900°C at a rate of 5°C / min and calcined for 4h.

[0163] Example 19

[0164] La 0.2 Sr 0.8 Fe 11.95 Cu 0.05 O 19 (x = 0.2, y = 0.05) composite oxygen carrier. The steps are as follows:

[0165] In deionized water at a temperature of 60°C, La(N03)3-6H20, Cu(N03)2, Sr(N03)2and Fe(N03)3-9H20 were added in a molar ratio of 4:1:16:239, respectively, to obtain a mixed solution of La 3+ , Cu 2+ , Sr 2+ , Fe 3+ with a concentration of 1 mol / L, and stirred for 10 min to obtain a precursor solution.

[0166] Then citric acid (citric acid:metal cation = 2.5:1) was added to the precursor solution and stirred to dissolve. After the citric acid was fully dissolved, the solution pH was adjusted to 7-8 with ammonia water. Then the solution was placed in a constant temperature water bath at 80°C and stirred until the water in the solution evaporated to a viscous gel, and then it was placed in a 150°C air drying oven for 12 h. After that, the dried sample was taken out and ground into a powder, which was placed in a muffle furnace and heated at a rate of 5°C / min from room temperature to 500°C and held for 4 h, and then heated at a rate of 5°C / min to 900°C and calcined for 4 h.

[0167] Example 20

[0168] La 0.2 Sr 0.8 Fe 11.6 Cu 0.4 O 19 (x = 0.2, y = 0.4) composite oxygen carrier. The steps are as follows:

[0169] In deionized water at a temperature of 60°C, La(N03)3-6H20, Cu(N03)2, Sr(N03)2and Fe(N03)3-9H20 were added in a molar ratio of 1:2:4:58, respectively, to obtain a mixed solution of La 3+ , Cu 2+ , Sr 2+ , Fe 3+ with a concentration of 1 mol / L, and stirred for 10 min to obtain a precursor solution.

[0170] Afterwards, the precursor solution is stirred to dissolve in the saturated glycine solution, and then polyethylene glycol with a molar amount of 1 times that of glycine is added and stirred to dissolve. Afterwards, the solution is stirred in a constant temperature water bath at 70°C until the water in the solution evaporates to a viscous colloid, and then the colloid is placed in a muffle furnace to dry for 2 h. After drying, the sample is taken out and ground into a powder, which is placed in a muffle furnace, and then heated at a rate of 5°C / min from room temperature to 500°C and kept for 4 h, and then heated at a rate of 5°C / min to 900°C and calcined for 4 h.

[0171] Example 21

[0172] Preparation of La 0.2 Sr 0.8 Fe 11.9 Cu 0.1 O 19 (x = 0.2, y = 0.1) composite oxygen carrier. The steps are as follows:

[0173] Preparation of La 0.2 Sr 0.8 Fe 12 O 19 oxygen carrier, and then La 0.2 Sr 0.8 Fe 11.9 Cu 0.1 O 19 composite oxygen carrier is prepared by impregnation. In deionized water at a temperature of 30°C, Cu(NO3)2(n(Cu):n(Fe) = 1:119) is stirred to dissolve, and then La 0.2 Sr 0.8 Fe 12 O 19 powder is stirred for 2 h. (NH4)2CO3 is added to the uniformly stirred precursor solution, and the amount of substance of ammonium carbonate is 1.5 times the total amount of substance of La, Sr, Fe, and Cu, and the pH is adjusted to 8-10. Rapid stirring is performed for 6 h while maintaining a constant temperature of 60°C. After stirring, the water bath is removed, and the sample is aged and left to stand at room temperature for 2 h, and then suction filtration is performed. The sample is washed 3 times with distilled water and 2 times with anhydrous ethanol, and then the sample is placed in a forced air drying oven and dried at a constant temperature of 120°C for 12 h. After drying, the sample is taken out and ground into a powder, which is placed in a muffle furnace, and then heated at a rate of 5°C / min from room temperature to 500°C and kept for 4 h, and then heated at a rate of 5°C / min to 900°C and calcined for 4 h.

[0174] Comparative Example 6

[0175] Preparation of Fe2O3 oxygen carrier. The steps are as follows:

[0176] In deionized water at 60°C, Fe(N03)3-9H20 was added to prepare a 1 mol / L solution, and stirred for 10 min. Then, the precipitant was prepared by adding ammonium carbonate (the amount of ammonium carbonate was 1.3 times the theoretical value) in deionized water at 60°C to prepare a (NH4)2CO3 solution with a concentration of 1 mol / L. Then, the uniformly stirred precursor solution was quickly added to the (NH4)2CO3 solution, and the pH was adjusted to 8-10. The solution was stirred rapidly at 60°C for 6 h. After stirring, the water bath was removed, and the sample was aged at room temperature for 1 h. Then, the sample was suction filtered, washed with distilled water 3 times, and placed in a blast drying oven for drying at 120°C for 12 h. Then, the dried sample was taken out, ground into powder, and placed in a muffle furnace. The temperature was raised to 500°C at a rate of 5°C / min, and then maintained for 4 h. Then, the temperature was raised to 900°C at a rate of 5°C / min, and calcined for 4 h.

[0177] Comparative Example 7

[0178] BaFe2O4(BaFe2) composite oxygen carrier was prepared. The steps were as follows:

[0179] In deionized water at 60°C, Ba(N03)2 and Fe(N03)3-9H20 were sequentially added in a molar ratio of 1:2 to obtain a mixed solution of Ba 2+ and Fe 3+ with a concentration of 1 mol / L, and stirred for 10 min. Then, the precipitant was prepared by adding ammonium carbonate (the amount of ammonium carbonate was 1.3 times the theoretical value) in deionized water at 60°C to prepare a (NH4)2CO3 solution with a concentration of 1 mol / L. Then, the uniformly stirred precursor solution was quickly added to the (NH4)2CO3 solution, and the pH was adjusted to 8-10. The solution was stirred rapidly at 60°C for 6 h. After stirring, the water bath was removed, and the sample was aged at room temperature for 1 h. Then, the sample was suction filtered, washed with distilled water 3 times, and placed in a blast drying oven for drying at 120°C for 12 h. Then, the dried sample was taken out, ground into powder, and placed in a muffle furnace. The temperature was raised to 500°C at a rate of 5°C / min, and then maintained for 4 h. Then, the temperature was raised to 900°C at a rate of 5°C / min, and calcined for 4 h.

[0180] Comparative Example 8

[0181] BaFe 12 O 19 (x = 0, y = 0, labeled as BaFe12) composite oxygen carrier was prepared. The steps were as follows:

[0182] In deionized water at 60℃, Ba(NO3)2 and Fe(NO3)3·9H2O were added sequentially in a molar ratio of 1:12 to obtain Ba 2+ Fe 3+ A mixed solution with a concentration of 1 mol / L was prepared and stirred for 10 min. Then, the precipitant was prepared by adding ammonium carbonate (1.3 times the theoretical amount) to deionized water at 60℃ to prepare a 1 mol / L (NH₄)₂CO₃ solution. The thoroughly stirred precursor solution was then rapidly added to the (NH₄)₂CO₃ solution, and the pH was adjusted to 8-10. The mixture was then rapidly stirred for 6 h while maintaining a constant temperature of 60℃. After stirring, the water bath was removed, and the mixture was allowed to age at room temperature for 1 h. It was then filtered, washed three times with distilled water, and placed in a forced-air drying oven to dry at a constant temperature of 120℃ for 12 h. The dried sample was then ground into powder and placed in a muffle furnace. The temperature was increased to 500℃ at a rate of 5℃ / min and held for 4 h. Then, the temperature was increased to 900℃ at a rate of 5℃ / min and calcined for 4 h.

[0183] Comparative Example 9

[0184] Preparation of Y x Ba 1-x Fe 12-y Cu y O 19 (x = 0.4, y = 0, labeled as Y0.4Ba0.6Fe12) composite oxygen carrier. The steps are as follows:

[0185] In deionized water at 60℃, Y(NO3)3·6H2O, Ba(NO3)2, and Fe(NO3)3·9H2O were added sequentially in a molar ratio of 2:3:60 to obtain Y 3+ Ba 2+ Fe 3+A mixed solution with a concentration of 1 mol / L was stirred for 10 min to obtain a precursor solution. Then, the precipitant was prepared: ammonium carbonate (1.3 times the theoretical amount) was added to deionized water at 60℃ to prepare a 1 mol / L (NH₄)₂CO₃ solution. The thoroughly stirred precursor solution was then rapidly added to the (NH₄)₂CO₃ solution, with the amount of ammonium carbonate being 1.3 times the total amount of Y, Ba, and Fe. The pH was adjusted to 8-10, and the mixture was rapidly stirred for 6 h while maintaining a constant temperature of 60℃. After stirring, the water bath was removed, and the mixture was allowed to age at room temperature for 1 h. It was then filtered, washed three times with distilled water, and placed in a forced-air drying oven to dry at a constant temperature of 120℃ for 12 h. Afterwards, the dried sample was taken out, ground into powder, placed in a muffle furnace, heated to 500°C at 5°C / min and held for 4 hours, and then calcined at 900°C at a heating rate of 5°C / min for 4 hours.

[0186] Powder X-ray diffraction (XRD) tests on the oxygen carriers prepared in Comparative Examples 6-9 were performed on an X'pert Pro Super XRD diffractometer from PAN Analytical, Netherlands. A copper target Kα line was used as the light source (λ = 0.15432 nm), a graphite monochromator was used, with a tube voltage of 40 kV and a tube current of 40 mA. The XRD results are as follows: Figure 16 As shown.

[0187] from Figure 16 It can be seen that the Fe2O3 oxygen carrier prepared in Comparative Example 6 mainly exhibits the Fe2O3 crystal phase, the BaFe2O4 oxygen carrier prepared in Comparative Example 7 mainly exhibits the spinel BaFe2O4 crystal phase, and the BaFe2O4 oxygen carrier prepared in Comparative Example 8 mainly exhibits the spinel BaFe2O4 crystal phase. 12 O 19 The oxygen carrier (labeled BaFe12) mainly exhibits the magnetoplumbourine (MP type) hexaferrate crystal phase, accompanied by small amounts of Fe2O3 and BaFe2O4 phases. Comparative Example 9 prepared Y... x Ba 1-x Fe 12-y Cu y O 19 (x = 0.4, y = 0), that is, Y 0.4 Ba 0.6 Fe 12 O 19 The oxygen carrier mainly exhibits the MP-type hexaferrate crystal phase, accompanied by the Fe2O3 phase. However, the addition of Y causes the diffraction peaks of the MP-type hexaferrate crystal phase to shift significantly towards higher 2θ values. 3+ Radius smaller than Ba 2+ This indicates that Y 3+ Successfully replaced Ba 2+Doping into MP-type hexaaluminate structure.

[0188] Example 22

[0189] Preparation of Y x Ba 1-x Fe 12-y Cu y O 19 (x = 0.4, y = 0.2) composite oxygen carrier, the steps are as follows:

[0190] In deionized water at a temperature of 60°C, Y(NO3)3·6H2O, Ba(NO3)2, Cu(NO3)2, and Fe(NO3)3·9H2O were added in a molar ratio of 2:3:1:59 to obtain a mixed solution with a concentration of 1 mol / L for each of Y, Ba, Fe, and Cu. 3+ , Cu 2+ , Ba 2+ , Fe 3+ The precursor solution was obtained by stirring for 10 min.

[0191] Then the precipitant was prepared: in deionized water at a temperature of 60°C, ammonium carbonate was added (the amount of ammonium carbonate was 1.3 times the theoretical value) to prepare a (NH4)2CO3 solution with a concentration of 1 mol / L.

[0192] After that, the precursor solution was quickly added to the (NH4)2CO3 solution, and the amount of substance of ammonium carbonate was 1.3 times the total amount of substance of Y, Ba, Fe, and Cu, and the pH was adjusted to 8-10. Under the condition of maintaining a constant temperature of 60°C, rapid stirring was carried out for 6 h. After stirring, the water bath was removed, and the sample was aged and placed at room temperature for 1 h. Then, the sample was filtered, washed with distilled water 3 times, and placed in a forced air drying oven for drying at a constant temperature of 120°C for 12 h. After that, the dried sample was taken out, ground into powder, and placed in a muffle furnace, which was heated to 500°C at a rate of 5°C / min and then maintained for 4 h, and then heated to 900°C at a rate of 5°C / min and calcined for 4 h.

[0193] Example 23

[0194] Preparation of Y x Ba 1-x Fe 12-y Cu y O 19 (x = 0.4, y = 0.4) composite oxygen carrier. The steps are as follows:

[0195] The specific operation is the same as in Example 22, except that the molar ratio of Y(NO3)3·6H2O, Ba(NO3)2, Cu(NO3)2, and Fe(NO3)3·9H2O in the precursor solution is 2:3:2:58.

[0196] Example 24

[0197] Preparation of Y x Ba 1-x Fe 12-y Cu y O 19 (x = 0.4, y = 0.6) composite oxygen carrier. The procedure was as follows:

[0198] The procedure was the same as in Example 22, except that the molar ratio of Y(N03)3-6H20, Ba(N03)2, Cu(N03)2to Fe(N03)3-9H20 in the precursor solution was 2:3:3:57.

[0199] Example 25

[0200] Preparation of Y x Ba 1-x Fe 12-y Cu y O 19 (x = 0.4, y = 0.8) composite oxygen carrier. The procedure was as follows:

[0201] The procedure was the same as in Example 22, except that the molar ratio of Y(N03)3-6H20, Ba(N03)2, Cu(N03)2to Fe(N03)3-9H20 in the precursor solution was 2:3:4:56.

[0202] X-ray diffraction test:

[0203] The powder X-ray diffraction test on the oxygen carriers Y prepared in Example 22, Example 23, Example 24 and Example 25 x Ba 1-x Fe 12-y Cu y O 19 (x = 0.4, y = 0.2, 0.4, 0.6, 0.8) was performed on an Xpert Pro Super X-ray diffractometer from PANalytical, the Netherlands. The copper target Ka line was used as the light source (l = 0.15432 nm), a graphite monochromator, tube voltage was 40 kV and tube current was 40 mA. The results of the X-ray diffraction test are shown in Figure 17

[0204] As can be seen from Figure 17 , all four fresh oxygen carriers were of MP-type hexaferrite and Fe203crystal phase, and no other crystal phase was formed. With the increase of Cu doping amount, it can be seen that the addition of Cu caused the diffraction peak of the MP-type hexaferrite crystal phase to move obviously to the low 2theta value direction, combined with the Fe 3+ radius being smaller than the Cu 2+ , it shows that Cu​2+ Successfully replaced Fe 3+ Doping was incorporated into Y-substituted MP-type hexaaluminates, forming Y- and Cu-cosubstituted MP-type Y-type aluminates. x Ba 1-x Fe 12-y Cu y O 19 Hexaferrate crystal phase.

[0205] Example 26

[0206] The cyclic stability of the oxygen carriers prepared in Comparative Examples 6-9, Example 24, and Example 25 was evaluated using an atmospheric pressure quartz fixed-bed reactor heated by an electric furnace. 0.45 g of 20-40 mesh oxygen carrier was used. In the fuel reactor, the fuel gas was methane (5 vol% CH4, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After reduction for 8 minutes, argon gas (99.99% Ar) was introduced at a flow rate of 50 mL / min and a temperature of 900 °C for 10 minutes. Then, oxygen (5 vol% O2, 95 vol% Ar) was introduced into the regeneration reactor at a flow rate of 15 mL / min, a reaction temperature of 900 °C, and a reaction pressure of atmospheric pressure. After the oxygen carrier was fully oxidized, argon gas was introduced again, followed by the fuel gas, and the reaction conditions were the same as the reduction reaction conditions described above. This cycle was repeated 10 times. The reactor outlet gas was analyzed online using a GAM-200 mass spectrometer. The results of the methane conversion and oxygen output evaluation are as follows: Figure 18 and Figure 19 As shown.

[0207] from Figure 18 and 19 As can be seen, in the 10th cycle, the methane conversion rate and oxygen output of Comparative Examples 6 (Fe2O3), 7 (BaFe2), 8 (BaFe12), and 9 (Y0.4Ba0.6Fe12) were only 36-84% and 0.99-1.90 mol / g, respectively. x Ba 1-x Fe 12-y Cu y O 19 (x=0.4, y=0.6, 0.8) The oxygen carrier maintained a high methane conversion rate (94-100%) and oxygen output (2.49-2.60 mol / g) throughout 10 cycles, indicating that the co-substitution of Y and Cu significantly improved the performance of the oxygen carrier, resulting in the highest methane conversion rate and oxygen output.

[0208] Example 27

[0209] The cyclic stability of the oxygen carriers prepared in Comparative Examples 6-9, Example 24, and Example 25 was evaluated using an atmospheric pressure quartz fixed-bed reactor heated by an electric furnace. 0.45 g of 20-40 mesh oxygen carrier was used. In the fuel reactor, the fuel gas was methane (5 vol% CH4, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After reduction for 20 minutes, argon gas (99.99% Ar) was switched to at a flow rate of 50 mL / min and a temperature of 900 °C, held for 10 minutes. Then, water vapor (5 vol% H2O, 95 vol% Ar) was introduced into the regeneration reactor at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. The reactor outlet gas was analyzed online using a GAM-200 mass spectrometer. The evaluation results are as follows: Figure 20 As shown.

[0210] from Figure 20 As can be seen from the data, compared to Comparative Example 6 (Fe2O3), Comparative Example 7 (BaFe2), Comparative Example 8 (BaFe12), and Comparative Example 9 (Y0.4Ba0.6Fe12), Y... x Ba 1-x Fe 12-y Cu y O 19 (x = 0.4, y = 0.6, 0.8) The oxygen carriers exhibited higher hydrogen concentrations, indicating that the co-substitution of Y and Cu significantly enhanced the reactivity of the oxygen carriers with water vapor, resulting in the highest hydrogen production.

[0211] Example 28

[0212] The cyclic stability of the oxygen carriers prepared in Comparative Examples 8, 9, 24, and 25 was evaluated using an atmospheric pressure quartz fixed-bed reactor heated by an electric furnace. 0.45 g of 20-40 mesh oxygen carrier was used. In the fuel reactor, methane (5 vol% CH4, 95 vol% Ar) was used as fuel gas at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After reduction for 20 minutes, argon (99.99% Ar) was introduced at a flow rate of 50 mL / min and a temperature of 900 °C for 10 minutes. Then, water vapor (5 vol% H2O, 95 vol% Ar) was introduced into the regeneration reactor at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. The reactor outlet gas was analyzed online using a GAM-200 mass spectrometer. The hydrogen purity and hydrogen yield were evaluated as follows: Figure 21 and Figure 22 As shown.

[0213] from Figure 21 and Figure 22As can be seen from the data, compared to Comparative Example 6 (Fe2O3), Comparative Example 7 (BaFe2), Comparative Example 8 (BaFe12), and Comparative Example 9 (Y0.4Ba0.6Fe12), Y... x Ba 1-x Fe 12-y Cu y O 19 The oxygen carriers (x = 0.4, y = 0.6, 0.8) exhibited higher hydrogen production (11.0-12.8 mL) and purity (99.93%), indicating that co-doping of Y and Cu significantly improved hydrogen production and purity.

[0214] Example 29

[0215] The cyclic stability of the oxygen carriers prepared in Comparative Examples 8, 9, 24, and 25 was evaluated using an atmospheric pressure quartz fixed-bed reactor heated by an electric furnace. 0.45 g of 20-40 mesh oxygen carrier was used. In the fuel reactor, the fuel gas was methane (5 vol% CH4, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After reduction for 20 minutes, argon gas (99.99% Ar) was introduced at a flow rate of 50 mL / min and a temperature of 900 °C for 10 minutes. Then, water vapor (5 vol% H2O, 95 vol% Ar) was introduced into the regeneration reactor at a flow rate of 15 mL / min, a reaction temperature of 900 °C, and a reaction pressure of atmospheric pressure. After the oxygen carrier was fully oxidized, argon gas was introduced again, followed by the fuel gas, and the reaction conditions were the same as the reduction reaction conditions described above. This cycle was repeated 10 times. The reactor outlet gas was analyzed online using a GAM-200 mass spectrometer. The hydrogen production evaluation results are as follows: Figure 23 As shown.

[0216] from Figure 23 It can be seen that, compared to Comparative Example 9 without Cu and Comparative Example 8 without Y and Cu (6.9-9.6 mL), Y x Ba 1-x Fe 12-y Cu y O 19 The oxygen carriers (x = 0.4, y = 0.6, 0.8) exhibited higher hydrogen production (8.0-12.8 mL), indicating that the Y and Cu co-doped oxygen carriers maintained the highest hydrogen production performance throughout 10 cycles.

[0217] Example 30

[0218] The cycle stability of the oxygen carriers prepared in Comparative Example 8, Comparative Example 9, Example 24, and Example 25 was evaluated using an atmospheric quartz fixed-bed reactor, and the heating method was electric furnace heating. 0.45 g of 20-40 mesh oxygen carriers was taken. In the fuel reactor, the fuel gas was methane (5 vol% CH4, 95 vol% Ar), the flow rate was 15 mL / min, the reaction temperature was 900°C, and the reaction pressure was atmospheric pressure. After reduction for 20 minutes, argon (99.99% Ar) was switched in, the flow rate was 50 mL / min, the temperature was 900°C, and it was maintained for 10 minutes. Then, in the regeneration reactor, water vapor (5 vol% H2O, 95 vol% Ar) was introduced, the flow rate was 15 mL / min, the reaction temperature was 900°C, and the reaction pressure was atmospheric pressure. After the oxygen carriers were fully oxidized, argon was switched again, and fuel gas was introduced again, and the reaction conditions were the same as the reduction reaction conditions described above, and this was performed for 10 cycles. The reactor outlet gas was analyzed online using a GAM-200 mass spectrometer, and the hydrogen production evaluation results are shown in Table 2. Figure 24

[0219] As can be seen from Figure 24 Comparative Example 9 without Cu and Comparative Example 8 without Y and Cu, Y x Ba 1-x Fe 12- y Cu y O 19 The oxygen carriers of Y and Cu co-doped (x=0.4, y=0.6, 0.8) showed higher hydrogen purity (99.93-99.95%), indicating that the Y and Cu co-doped oxygen carriers maintained the highest hydrogen purity (more than 99.93%) and high carbon deposition resistance in 10 cycles.

[0220] Example 31

[0221] ​The cyclic stability of the oxygen carriers prepared in Comparative Examples 8, 9, 24, and 25 was evaluated using an atmospheric pressure quartz fixed-bed reactor heated by an electric furnace. 0.45 g of 20-40 mesh oxygen carrier was used. In the fuel reactor, the fuel gas was methane (5 vol% CH4, 95 vol% Ar) at a flow rate of 15 mL / min, the reaction temperature was 900 °C, and the reaction pressure was atmospheric pressure. After reduction for 20 minutes, argon gas (99.99% Ar) was introduced at a flow rate of 50 mL / min and a temperature of 900 °C for 10 minutes. Then, water vapor (5 vol% H2O, 95 vol% Ar) was introduced into the regeneration reactor at a flow rate of 15 mL / min, a reaction temperature of 900 °C, and a reaction pressure of atmospheric pressure. After the oxygen carrier was fully oxidized, argon gas was introduced again, followed by the fuel gas, and the reaction conditions were the same as the reduction reaction conditions described above. This cycle was repeated 10 times. The reactor outlet gas was analyzed online using a GAM-200 mass spectrometer. The results of the water vapor oxygen supply evaluation are as follows: Figure 25 As shown.

[0222] from Figure 25 It can be seen that, compared to Comparative Example 9 without Cu and Comparative Example 8 without Y and Cu, Y x Ba 1-x Fe 12- y Cu y O 19 (x=0.4, y=0.6, 0.8) The oxygen carriers obtained higher oxygen content from water vapor, indicating that the oxygen carriers co-substituted by Y and Cu significantly improved their reactivity with water vapor and had the highest oxygen carrying capacity.

[0223] Example 32

[0224] The oxygen carrier prepared in Example 22 was evaluated for activity using a fixed-bed reactor. The amount of oxygen carrier used was 0.45 g, and the particle size was 20-40 mesh. The fuel gas composition was 5% CH4 / Ar, the flow rate was 15 mL / min, the reaction temperature was 1000 °C, the reaction time was 15 min, and the reaction pressure was atmospheric pressure.

[0225] Example 33

[0226] The oxygen carrier prepared in Example 25 was evaluated for activity using a fixed-bed reactor. The amount of oxygen carrier used was 0.45 g, and the particle size was 20-40 mesh. The fuel gas composition was 5% CH4 / Ar, the flow rate was 15 mL / min, the reaction temperature was 600 °C, the reaction time was 15 min, and the reaction pressure was atmospheric pressure.

[0227] Example 34

[0228] Preparation of Y x Ba1-x Fe 12-y Cu y O 19 (x = 0.4, y = 0.2) Composite oxygen carrier, the steps are as follows:

[0229] In deionized water at 60℃, Y(NO3)3·6H2O, Ba(NO3)2, Cu(NO3)2, and Fe(NO3)3·9H2O were added sequentially in a molar ratio of 2:3:1:59 to obtain Y 3+ Cu 2+ Ba 2+ Fe 3+ A mixed solution with a concentration of 1 mol / L was stirred for 10 min to obtain a precursor solution.

[0230] Then, the precipitant was prepared: ammonium carbonate (the amount of ammonium carbonate was 1.3 times the theoretical value) was added to deionized water at a temperature of 60℃ to prepare a (NH4)2CO3 solution with a concentration of 1 mol / L.

[0231] The precursor solution was then rapidly added to the (NH4)2CO3 solution, with the amount of ammonium carbonate being 1.3 times the total amount of Y, Ba, Fe, and Cu. The pH was adjusted to 8-10, and the mixture was rapidly stirred for 6 hours while maintaining a constant temperature of 60℃. After stirring, the water bath was removed, and the mixture was allowed to age at room temperature for 1 hour. It was then filtered, washed three times with distilled water, and placed in a forced-air drying oven to dry at a constant temperature of 120℃ for 12 hours. The dried sample was then ground into powder and placed in a muffle furnace. The temperature was increased to 500℃ at a rate of 5℃ / min and held for 4 hours. Then, the temperature was increased to 1100℃ at a rate of 3℃ / min and calcined for 4 hours.

[0232] Example 35

[0233] Preparation of Y x Ba 1-x Fe 12-y Cu y O 19 (x = 0.4, y = 0.4) Composite oxygen carrier, the steps are as follows:

[0234] In deionized water at 60℃, Y(NO3)3·6H2O, Ba(NO3)2, Cu(NO3)2, and Fe(NO3)3·9H2O were added sequentially in a molar ratio of 2:3:2:58 to obtain Y 3+ Cu 2+ Ba 2+ Fe 3+ A mixed solution with a concentration of 1 mol / L was stirred for 10 min to obtain a precursor solution.

[0235] Then the preparation of the precipitant was carried out: in deionized water at a temperature of 60°C, ammonium carbonate was added (the amount of ammonium carbonate was 1.3 times the theoretical value) to prepare a (NH4)2CO3 solution with a concentration of 1 mol / L.

[0236] Then the precursor solution was quickly added to the (NH4)2CO3 solution, the amount of substance of ammonium carbonate was 1.3 times the total amount of substance of Y, Ba, Fe and Cu, and the pH was adjusted to 8-10, and stirred rapidly for 5 h under the condition of keeping the temperature at 70°C. After stirring, the water bath was removed and the sample was aged at room temperature for 2 h, then filtered, washed with distilled water 3 times, and placed in a blast drying oven and dried at 120°C for 12 h. Then the dried sample was taken out and ground into powder, and placed in a muffle furnace, heated to 500°C at a rate of 5°C / min and kept for 4 h, and then calcined at 900°C at a rate of 5°C / min for 4 h.

[0237] Example 36

[0238] Preparation of Y x Ba 1-x Fe 12-y Cu y O 19 (x=0.4, y=0.6) composite oxygen carrier, the steps are as follows:

[0239] In deionized water at a temperature of 60°C, Y(NO3)3·6H2O, Ba(NO3)2, Cu(NO3)2 and Fe(NO3)3·9H2O were added in the order of 2:3:3:57 molar ratio to obtain a mixed solution with a concentration of 1.2 mol / L, and stirred for 10 min to obtain a precursor solution. 3+ , Cu 2+ , Ba 2+ , Fe 3+

[0240] Then the preparation of the precipitant was carried out: in deionized water at a temperature of 60°C, ammonium carbonate was added (the amount of ammonium carbonate was 1.3 times the theoretical value) to prepare a (NH4)2CO3 solution with a concentration of 1 mol / L.

[0241] ​After that, the precursor solution is quickly added into the (NH4)2CO3 solution, the amount of substance of ammonium carbonate is 1.3 times of the total amount of substance of Y, Ba, Fe and Cu, and the pH is adjusted to 8-10, under the condition of keeping the temperature at 60℃, the stirring is kept for 6 hours. After the stirring is finished, the water bath is taken out, and the sample is aged at room temperature for 1 hour, then filtered, washed with distilled water for 3 times, and dried in a blast drying oven at 120℃ for 12 hours. After that, the dried sample is taken out, ground into powder, and placed in a muffle furnace, heated to 500℃ at a rate of 5℃ / min, kept for 4 hours, then heated to 900℃ at a rate of 5℃ / min, and calcined for 4 hours.

[0242] The above description is only the preferred embodiment of the present application, and does not limit the present application in any form; any person skilled in the art can make many possible modifications, equivalent replacements or improvements to the present application by using the above method without departing from the scope of the technical scheme of the present application. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiment according to the technical essence of the present application without departing from the content of the technical scheme of the present application still belongs to the protection scope of the technical scheme of the present application.

Claims

1. A low-quality coke breeze tail gas and sealed calcium carbide furnace gas chemical looping hydrogen oxygen carrier, characterized in that, The oxygen carrier has a chemical formula of A x B 1-x Fe 12-y Cu y O 19 , 0 < x < 1, 0 < y < 1, A is La, B is Sr; or A is Y, B is Ba.

2. The low-quality coke breeze tail gas and closed-down calcium carbide furnace gas chemical-looping hydrogen oxygen carrier according to claim 1, characterized in that, 0.2≤x≤0.6, 0.05≤y≤0.

8.

3. The low-quality coke oven tail gas and closed-down calcium carbide plant gas chemical-looping hydrogen oxygen carrier according to claim 1, characterized in that, x = 0.2, 0.4 or 0.6, y = 0.05, 0.1, 0.2, 0.4, 0.6 or 0.

8.

4. A method for preparing a low-quality coke breeze tail gas and a closed calcium carbide furnace gas chemical looping hydrogen oxygen carrier according to any one of claims 1 to 3, characterized by, Includes the following steps: Add La, Sr, Cu, and Fe precursors, or Y, Ba, Cu, and Fe precursors, to deionized water and mix thoroughly to obtain a precursor solution. Add citric acid to the precursor solution and stir until dissolved. Adjust the pH to 7-8, then stir under heating until viscous. Dry, grind, and calcine to obtain a low-quality semi-coke tail gas and a closed calcium carbide furnace gas chemical looping hydrogen carrier. The amount of citric acid is 1.5-2.5 times the total amount of La, Sr, Cu, and Fe, and the concentration of La, Sr, Cu, and Fe precursors in the precursor solution is 0.8-1.3 mol / L.

5. A method for preparing a low-quality coke breeze tail gas and closed calcium carbide furnace gas chemical looping hydrogen oxygen carrier according to any one of claims 1-3, characterized by, Includes the following steps: To deionized water, add precursors of La, Sr, Cu, and Fe, or precursors of Y, Ba, Cu, and Fe, and mix thoroughly to obtain a precursor solution. Add a saturated glycine solution and polyethylene glycol to the precursor solution and stir until dissolved. Dry, grind, and calcine to obtain a low-quality semi-coke tail gas and a closed calcium carbide furnace gas chemical looping hydrogen carrier. The amount of saturated glycine is 1.3-1.5 times the total amount of La, Sr, Cu, and Fe, and the amount of polyethylene glycol is... The amount of saturated glycine is 0.8-1.2 times the amount of saturated glycine, and the concentrations of the precursors La, Sr, Cu, and Fe in the precursor solution are all 0.8-1.3 mol / L; the amount of saturated glycine is 1.3-1.5 times the total amount of Y, Ba, Cu, and Fe, and the amount of polyethylene glycol is 0.8-1.2 times the amount of saturated glycine, and the concentrations of the precursors Y, Ba, Cu, and Fe in the precursor solution are all 0.8-1.3 mol / L.

6. A method for preparing a low-quality coke breeze tail gas and a closed calcium carbide furnace gas chemical looping hydrogen oxygen carrier according to any one of claims 1 to 3, characterized by, Includes the following steps: A precursor of Cu is added into deionized water and stirred to dissolve, and then La x Sr 1-x Fe 12 O 19 powder or Y x Ba 1-x Fe 12 O 19 The powder is added into a precursor solution of Cu and stirred uniformly, then a saturated ammonium carbonate solution is added and mixed uniformly, filtered, dried to obtain a powder, and the powder is calcined to obtain an oxygen carrier for hydrogen production by low-quality blue charcoal tail gas and sealed calcium carbide furnace gas chemical looping; wherein the amount of substance of the saturated ammonium carbonate is 1.3-1.5 times the total amount of substance of La, Sr, Cu and Fe, and the concentration of the precursors of La, Sr, Cu and Fe in the precursor solution is 0.8-1.3 mol / L; the amount of substance of the saturated ammonium carbonate is 1.3-1.5 times the total amount of substance of Y, Ba, Cu and Fe, and the concentration of the precursors of Y, Ba, Cu and Fe in the precursor solution is 0.8-1.3 mol / L.

7. A method for preparing a low-quality coke breeze tail gas and a closed calcium carbide furnace gas chemical looping hydrogen oxygen carrier according to any one of claims 1 to 3, characterized by, Includes the following steps: Add the precursors of La, Sr, Fe and Cu or Y, Ba, Cu and Fe to deionized water, mix well, and obtain a precursor solution. Add the precursor solution to a saturated ammonium carbonate solution, mix well, adjust the pH to 8-10, stir at 60-70℃ for 5-6 hours, then age and let stand for 1-2 hours, filter and dry, then calcine at 400-500℃ for 4-5 hours and calcinate at 800-1100℃ for 4-5 hours to obtain low-quality semi-coke tail gas and closed calcium carbide furnace gas chemical looping hydrogen production oxygen carrier. The total amount of substance of the saturated ammonium carbonate is 1.3-1.5 times the total amount of substance of La, Sr, Cu and Fe, and the concentration of the precursors of La, Sr, Cu and Fe in the precursor solution is 0.8-1.3 mol / L; the total amount of substance of the saturated ammonium carbonate is 1.3-1.5 times the total amount of substance of Y, Ba, Cu and Fe, and the concentration of the precursors of Y, Ba, Cu and Fe in the precursor solution is 0.8-1.3 mol / L.

8. The application of the oxygen carrier for chemical looping reaction in a chemical looping process for hydrogen production from low-quality coke oven tail gas and closed calcium carbide furnace gas according to any one of claims 1-3, wherein a fuel reactor and a hydrogen production reactor are connected in communication, and the oxygen carrier circulates between the fuel reactor and the hydrogen production reactor; the oxygen carrier reacts with the low-quality coke oven tail gas and the closed calcium carbide furnace gas in the fuel reactor at 600-1000 ℃, and at the same time, the oxygen carrier is reduced by the reducing gas in the low-quality coke oven tail gas or the reducing gas in the closed calcium carbide furnace gas; the reduced oxygen carrier is oxidized and regenerated in the hydrogen production reactor with water vapor at 600-1000 ℃, and at the same time, H2 is produced, and the reducing gas in the low-quality coke oven tail gas and the closed calcium carbide furnace gas includes CH4, CO and H2.

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