Preparation method of biomass gasification adsorption enhanced reforming hydrogen production catalyst

Abstract

This invention discloses a method for preparing a biomass gasification adsorption-enhanced reforming hydrogen production catalyst, belonging to the fields of catalyst preparation and biomass thermal conversion technology. The catalyst of this invention uses CeO2 as a high-content support and Ni and Fe as active components. The method employs a co-impregnation method to simultaneously load a nickel active phase precursor and an iron co-catalytic precursor onto the support surface; after drying, the precursor powder is placed under an inert atmosphere and processed according to the following relationship... T ×0.01+ t By calcining at a temperature T of 10°C with a time t in a complementary correlation, a composite catalytic system with strong interactions is constructed. This invention also provides the application of the above catalyst in combination with a calcium-based adsorbent in biomass adsorption-enhanced reforming for hydrogen production. This invention enhances the catalyst's resistance to carbon deposition by regulating the bimetallic electronic structure and the oxygen storage and release capacity of the support. Simultaneously, by combining a segmented temperature control process, it achieves kinetic synergy between in-situ CO2 capture and catalytic reforming, significantly increasing the green hydrogen content in the syngas.

Description

Technical Field

[0001] This invention relates to the fields of catalyst preparation and biomass thermal conversion technology, and in particular to a method for preparing a biomass gasification adsorption-enhanced reforming hydrogen production catalyst. Background Technology

[0002] With the continued growth of global energy demand and the urgency of addressing climate change, finding green and low-carbon alternative energy sources has become an international consensus. Utilizing thermochemical technologies to convert biomass into high-value-added syngas (hydrogen, carbon monoxide, etc.) has become a research hotspot in the field of renewable energy. Syngas is not only an important chemical feedstock but also a key precursor for producing high-purity hydrogen. However, the pyrolysis gasification products of biomass have complex compositions, containing large amounts of tar vapor and the greenhouse gas carbon dioxide (CO2), resulting in low calorific value of the final gas and high subsequent separation costs. Therefore, developing reaction systems with high reforming activity and selective CO2 capture capabilities is of great significance for achieving the efficient utilization of biomass energy.

[0003] Syngas reforming primarily relies on catalysts for the directional conversion of complex organic components. Nickel (Ni)-based catalysts, due to their superior ability to break carbon-carbon single bonds (CC) and carbon-hydrogen bonds (CH), play a crucial role in catalytic tar cracking, steam methane reforming (SMR), and water gas shift (WGS) reactions, significantly reducing activation energy and improving hydrogen production efficiency. However, traditional nickel-based catalysts face severe deactivation challenges in the actual operating conditions of biomass-enhanced reforming. Because the reforming reaction involves complex carbon conversion pathways, the surface of the active component Ni is highly susceptible to filamentous or coated carbon deposits due to methane cracking or carbon monoxide dismutation, leading to irreversible physical shielding and poisoning of active sites. Simultaneously, under high-temperature pyrolysis / gasification conditions of 600–900 °C, Ni particles are prone to grain sintering and agglomeration, resulting in a sharp reduction in catalyst specific surface area and continuous decline in catalytic activity. Furthermore, existing Ni-based catalysts and Sorption Enhanced Steam Reforming (SESR) processes have significant shortcomings in kinetic matching. In particular, within a specific reaction temperature range, the reforming rate of the catalyst is difficult to effectively coordinate with the CO2 capture kinetics of the calcium-based adsorbent, which limits the system's ability to overcome thermodynamic equilibrium limitations and obtain high-purity hydrogen. Summary of the Invention

[0004] In view of the aforementioned deficiencies in the prior art, the present invention aims to provide a method for preparing a biomass gasification adsorption-enhanced reforming hydrogen production catalyst (CeO2-Ni-Fe catalyst) with specific calcination regime regulation. This method is designed to adjust the electronic structure of surface active sites by introducing an iron (Fe) component as a co-catalyst, and to enhance anti-carbon deposition performance by using a cerium dioxide (CeO2) support with high oxygen storage capacity (OSC). Combined with a specific temperature-time complementary calcination process, the present invention aims to construct a catalytic system with high dispersibility and high thermal stability. With a layered layout and segmented temperature control process, the CO2 adsorption section and the catalytic reforming section operate synergistically within their respective optimal kinetic windows, thereby significantly increasing the hydrogen content during the biomass gasification process while ensuring long-term stable system operation.

[0005] To achieve the above objectives, the technical solution provided by the present invention is as follows: In a first aspect of the present invention, a method for preparing a biomass gasification adsorption-enhanced reforming hydrogen production catalyst is provided, comprising the following steps: (1) Cerium dioxide is ground to obtain a powdered carrier; (2) Dissolve the nickel-containing active phase precursor and the iron-containing co-catalytic precursor in water to obtain a mixed salt solution; (3) Add the powdered carrier to the mixed salt solution and mix to obtain a solid-liquid mixture; (4) The solid-liquid mixture is dried and ground to obtain precursor powder; (5) The precursor powder was calcined under an inert atmosphere to obtain a biomass gasification adsorption-enhanced reforming hydrogen production catalyst.

[0006] Preferably, in step (2), the nickel-containing active phase precursor includes a soluble nickel salt; and the iron-containing co-catalytic precursor includes a soluble iron salt.

[0007] More preferably, the soluble nickel salt includes one or both of nickel nitrate and nickel acetate; the soluble iron salt includes one or both of ferric nitrate and ferric acetate.

[0008] Those skilled in the art should understand that the aforementioned water-soluble metal salts include pure anhydrous metal salts or their hydrates, which are essentially different forms of the same compound and can all be used in the above steps to prepare mixed salt solutions of the corresponding precursor salts. Furthermore, those skilled in the art can employ appropriate auxiliary dissolution procedures based on actual conditions, such as using ultrasonic-assisted treatment during the dissolution process, to ensure complete dissolution of the precursor salts.

[0009] Preferably, in step (3), the mixing includes stirring at room temperature for 2 to 4 hours.

[0010] Preferably, in step (4), the drying includes treatment at 80~105 °C for 8~12 h.

[0011] Preferably, in step (5), the calcination temperature and calcination time of the calcination treatment satisfy a complementary relationship, and the calcination temperature and calcination time satisfy the following relationship: T ×0.01+ t =10 in, T The calcination temperature is ℃; t The calcination time is in hours (h). T The value range is 400~700℃. t The value range is 3~6 h.

[0012] Preferably, in step (5), the biomass gasification adsorption-enhanced reforming hydrogen production catalyst includes 70 wt.%~90 wt.% cerium dioxide and the balance active material; the active material includes nickel and iron, and the mass ratio of nickel to iron is 3:2~4:1.

[0013] In a second aspect of the present invention, a biomass gasification adsorption-enhanced reforming hydrogen production catalyst is provided, which is prepared using the preparation method of the first aspect of the present invention.

[0014] Based on the preparation method provided in the first aspect of the present invention and the biomass gasification adsorption-enhanced reforming hydrogen production catalyst provided in the second aspect, the design concept and principle of the present invention are as follows: To address the technical challenges of low reforming efficiency due to the complex composition of volatile matter during biomass pyrolysis / gasification, and catalyst deactivation due to carbon buildup and sintering, this invention mainly makes the following two improvements: On the one hand, regarding the functional construction of the support, this invention employs a high proportion (70 wt.%~90 wt.%) of CeO2 as a functionally integrated support, breaking through the traditional catalyst design logic of "physical support plus multiple additives" (for example, in existing technologies such as CN101884928A, a low content of CeO2 is used as an anti-carbon deposition additive). Compared to the traditional model that relies on inert materials to provide specific surface area and support, supplemented by functional additives to maintain stability, this invention designs a high proportion of CeO2 support, which, with its inherent redox activity, achieves a high degree of integration of physical support, thermal stability, and chemical activation, offering significant advantages in cost reduction and process simplification. During the calcination process, this invention employs a temperature-time complementary calcination process, inducing the generation of CeO2. 3+The structure, coexisting with oxygen vacancies, anchors Ni and Fe particles through strong metal-support interaction (SMSI), preventing sintering and agglomeration, while simultaneously enhancing interfacial charge transfer and promoting hydrogen spillover. During the reaction, CeO2, possessing excellent oxygen storage and release capabilities, is released through Ce... 4+ / Ce 3+ The redox cycle releases active lattice oxygen and generates oxygen vacancies. Active oxygen species migrate from the support to the metal active site interface, oxidizing the carbon precursor deposited on the active phase surface in situ to CO or CO2. This mechanism achieves self-cleaning of the catalyst surface, suppresses the physical shielding of active sites caused by carbon deposition, and ensures the stability of the catalyst under complex reaction environments. Simultaneously, Ce... 3+ The formed Lewis acid sites enhance the synergistic adsorption of aromatic macromolecules such as biomass tar, enabling the catalyst to exhibit tar conversion activity that surpasses that of traditional alumina (Al2O3) supported catalysts (for example, in existing technologies such as CN120132858A, Al2O3 is used as the catalyst support).

[0015] On the other hand, regarding the synergistic regulation of active components and additives, this invention constructs a multi-metal active center by loading a proportionally proportioned active phase Ni and a co-catalyst Fe. The active component Ni is responsible for catalyzing the breaking of C-C bonds and CH bonds in long-chain hydrocarbons in biomass pyrolysis gas, serving as the active center for tar cracking, steam reforming, and water-gas shift reactions. The introduction of the additive Fe modulates the electronic structure of Ni, lowering the activation energy by altering the electron density of the active sites, and enhancing the dissociation of steam using its strong affinity for oxygen-containing species, generating active oxygen fragments that synergistically remove carbon deposits with the CeO2 support.

[0016] This invention is based on an impregnation method, which achieves simultaneous loading of bimetallic components onto a cerium dioxide support through a one-step impregnation process. This process is simple, energy-efficient, and produces minimal wastewater and exhaust emissions, significantly reducing production costs and equipment requirements, and possesses great potential for large-scale industrial application. Simultaneously, the co-impregnation method ensures deep mixing of the Ni and Fe precursors at the molecular level, promoting the formation of strong bimetallic interactions during subsequent calcination and constructing highly dispersed active sites.

[0017] To address the technical problem of traditional high-temperature, extensive calcination processes suppressing the functionality of the CeO2 support, this paper proposes a refined calcination process with optimized conditions, establishing a complementary relationship between calcination temperature and time. This innovative process transforms traditional "high-temperature, extensive" alloying into "low-temperature, precise" interface engineering. The lower temperature inhibits significant sintering of CeO2 grains and oxygen vacancy collapse, preventing Ni metal particle agglomeration and constructing a high-density support-metal active interface. Meanwhile, phase-assisted time compensation facilitates the diffusion of lattice oxygen and CeO2. 3+ The establishment of redox centers provides a sufficient kinetic window.

[0018] In a third aspect of the invention, the application of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst of the second aspect of the invention is provided, including: as a catalyst, in combination with a calcium-based adsorbent, for biomass gasification adsorption-enhanced reforming hydrogen production.

[0019] Preferably, the biomass gasification adsorption-enhanced reforming hydrogen production adopts a staged reaction process, including: Biomass pyrolysis / gasification section: Pretreated biomass is pyrolyzed at 700~900 ℃ and gasified in a steam atmosphere to produce syngas containing hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO), and methane (CH4); Adsorption section: filled with calcium-based adsorption material with carbon dioxide adsorption function, used to capture carbon dioxide generated by the reaction in situ at 800~1000 ℃; Reforming section: filled with biomass gasification adsorption-enhanced reforming hydrogen production catalyst, used to catalytically reform syngas at 500~700 ℃ to obtain hydrogen-rich syngas; The aforementioned calcium-based adsorbent and biomass gasification adsorption-enhanced reforming hydrogen production catalyst are arranged in layers or placed in different temperature control zones within the reactor.

[0020] More preferably, in the segmented reaction process, the mass percentage of each segment is as follows: biomass 40%~60%, calcium-based adsorbent material 20%~30%, and biomass gasification adsorption-enhanced reforming hydrogen production catalyst 20%~30%.

[0021] Guided by the above process steps, technicians can select common forms of calcium-based adsorbents in the field, such as calcium oxide and its derivatives (including dolomite, carbide slag, etc.), based on actual conditions to complete the in-situ capture of carbon dioxide.

[0022] Based on the application provided in the third aspect of this invention, the design concept and principle of this invention are as follows: This application aims to overcome the thermodynamic equilibrium limitations in biomass thermal conversion by constructing an adsorption-enhanced reforming system through multi-stage temperature control and spatial optimization of multifunctional materials. Its core design logic lies in the in-situ capture of CO2 generated by the catalytic reforming reaction, thereby controlling the reaction direction in real time and maximizing hydrogen production efficiency.

[0023] On the one hand, regarding reactor layout and functional coupling, the present invention employs a layered arrangement of biomass, catalyst, and calcium-based materials. The calcium-based adsorbent acts as an adsorbent in the adsorption section, utilizing its adsorption of CO2 for in-situ capture; the CeO2-Ni-Fe catalyst is placed in the reforming section for deep catalysis of the volatiles from biomass pyrolysis. This physically separated arrangement effectively avoids solid-phase reactions between the active components and the calcium-based materials at high temperatures, protecting the microstructure of the catalyst, and facilitating the regeneration of the adsorbent and the recycling of the catalyst after the reaction.

[0024] On the other hand, regarding the matching and control of process thermodynamics and kinetics, this invention employs a three-stage temperature control technology (preferably a gradient distribution of 800 ℃-800 ℃-650 ℃). This temperature range setting ensures that biomass is fully pyrolyzed and gasified at high temperatures while keeping the reforming catalyst within its optimal reaction kinetic window. By lowering the adsorption section temperature, the carbon fixation capacity of the calcium-based material is enhanced. The real-time reduction in CO2 concentration forces key hydrogen production steps, such as the water-gas shift reaction, to shift significantly towards the product direction, thereby obtaining high-abundance hydrogen-rich syngas in the reforming section.

[0025] As presented in the specific embodiments of the present invention, in some preferred embodiments, the biomass raw material is wheat straw (ground to 80 mesh), and the calcium-based material is made by burning waste eggshells at 800 ℃ in a nitrogen environment. The weight ratio of wheat straw, calcium-based material and CeO2-Ni-Fe catalyst is 2:1:1. The reaction is carried out in a nitrogen and water vapor environment. The pyrolysis temperature is 800 ℃, the adsorption temperature is 800 ℃, the reforming temperature is 650 ℃, and the time is 1.5 h.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The preparation process is green, low-energy, and easy to industrialize. This invention employs a co-impregnation method to prepare the catalyst, achieving deep mixing and simultaneous loading of the active component Ni and the auxiliary agent Fe at the molecular level through a one-step impregnation. Compared to stepwise impregnation or co-precipitation processes, this process is simpler, consumes less solvent, and effectively reduces energy consumption and wastewater pollution during preparation, significantly improving production efficiency and demonstrating excellent potential for large-scale industrial application.

[0027] 2. The catalyst possesses excellent anti-carbon deposition properties and self-cleaning ability. Utilizing the superior oxygen storage and release capacity of the CeO2 support and the electronic regulation effect of the Fe co-catalyst, an active center with synergistic catalytic activity is constructed. The support, through Ce... 4+ / Ce 3 + The redox cycle releases active lattice oxygen, which can oxidize carbon precursors deposited on the surface of active sites in situ, effectively suppressing the physical shielding of active sites by carbon deposition. Under the same loading, the stability and hydrogen production activity of the Ni-Fe system of this invention are significantly better than other bimetallic systems such as Ni-Mo.

[0028] 3. Excellent thermal stability, effectively inhibiting high-temperature sintering of active metals. This invention utilizes a specific temperature-time complementary calcination process to construct highly dispersed and strongly bound active centers on the CeO2 support surface through kinetic compensation effects. This strong interaction effectively anchors the metal particles, inhibiting their thermal migration and agglomeration under high-temperature pyrolysis / gasification conditions, ensuring the continuous catalytic activity of the catalyst in the segmented process.

[0029] 4. Significantly increased green hydrogen content, achieving efficient utilization of biomass energy. This invention applies a catalyst in combination with a calcium-based adsorbent in a segmented enhanced reforming process, breaking the thermodynamic equilibrium limitation of the reaction through in-situ CO2 capture. When the catalyst calcination temperature and calcination time are preferably 500 ℃ and 5 h, under three-stage temperature control conditions of 800 ℃-800 ℃-650 ℃, the green hydrogen yield is 719.56 mL / g, which is about 21.5% higher than the blank group with only adsorbent and no catalyst (592.03 mL / g), and about 42.3% higher than the blank group with neither adsorbent nor catalyst (505.63 mL / g). At the same time, it significantly reduces the yield of CH4 in the product, achieving high-quality conversion of syngas. Attached Figure Description

[0030] Figure 1 This is a schematic flowchart of the preparation method of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst in Example 1; Figure 2 The images are scanning electron microscope (SEM) images of the biomass gasification adsorption-enhanced reforming hydrogen production catalysts corresponding to Examples 1 and 5; (a) corresponds to Example 1, and (b) corresponds to Example 5. Figure 3 This is a transmission electron microscope (TEM) image of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst corresponding to Example 1. Detailed Implementation

[0031] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0032] The following embodiments and comparative examples involve the following general experimental conditions and apparatus: Reaction apparatus: A three-stage temperature-controlled vertical tube furnace is used.

[0033] Feeding method: Biomass raw material (80-mesh wheat straw) is placed in a glass basket and placed in the first temperature zone of the tube furnace; calcium-based adsorbent and catalyst are respectively loaded into special glass tubes and placed in the second and third temperature zones.

[0034] Detection and analysis: The concentration data of the outlet gas (H2, CO, CO2, CH4) are monitored and recorded in real time using a gas analyzer.

[0035] Data processing: Integrate the gas production per unit mass of biomass per minute.

[0036] Example 1 This embodiment provides a method for preparing a biomass gasification adsorption-enhanced reforming hydrogen production catalyst, the process of which is as follows: Figure 1 As shown, the steps are as follows: (1) A total of 3 g of biomass gasification adsorption-enhanced reforming hydrogen production catalyst was prepared; 2.7 g of CeO2 particles were weighed and ground into powder in an agate mortar for later use, and a powdered support was obtained. (2) Weigh 1.19 g of nickel nitrate hexahydrate and 0.43 g of ferric nitrate nonahydrate, dissolve them in deionized water and perform ultrasonic-assisted treatment to ensure complete dissolution, to obtain a mixed salt solution; (3) Add the powdered carrier to the mixed salt solution and stir magnetically at room temperature for 4 h to obtain a solid-liquid mixture; (4) The solid-liquid mixture was dried in an oven at 105 °C for 12 h. After being taken out, it was ground into powder in an agate mortar to obtain precursor powder. (5) Place the powder in a horizontal tube furnace, introduce nitrogen gas, and calcine at 500 °C for 5 h (to satisfy the temperature-time complementary relationship) to obtain CeO2-Ni-Fe catalyst, namely biomass gasification adsorption-enhanced reforming hydrogen production catalyst.

[0037] This embodiment also provides a biomass gasification adsorption-enhanced reforming hydrogen production catalyst prepared by the above method and its application. The application steps of the CeO2-Ni-Fe catalyst are as follows: Step 1: Weigh 1 g of 80-mesh wheat straw and place it in a glass basket for later use; Step 2: Weigh 0.5 g of CeO2-Ni-Fe catalyst and 0.5 g of calcium-based material (made from eggshells) and place them separately into special glass tubes; Step 3: Place the basket and glass tube into the corresponding temperature zone of the vertical tube furnace, set the three short temperature zones to 800℃-800℃-600℃ respectively, and introduce nitrogen (300 mL / min) and water vapor (4.8 mL / min) to carry out the pyrolysis / gasification adsorption enhanced reforming reaction.

[0038] Experimental results: The gas analyzer recorded data in real time, and the H2 integral area was calculated using Origin software. The converted green hydrogen yield was 719.56 mL / g, which was the highest value among all implementation groups.

[0039] Example 2 This embodiment provides a method for preparing a biomass gasification adsorption-enhanced reforming hydrogen production catalyst, which is basically the same as that in Example 1, except that the calcination temperature in step (5) of this embodiment is 400 ℃ and the calcination time is 6 h.

[0040] This embodiment also provides a biomass gasification adsorption-enhanced reforming hydrogen production catalyst prepared by the above preparation method and its application. The application method is the same as that in Example 1. The experimental results, calculated by integration, show that the H2 yield of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst prepared in this embodiment is 688.07 mL / g.

[0041] Example 3 This embodiment provides a method for preparing a biomass gasification adsorption-enhanced reforming hydrogen production catalyst, which is basically the same as that in Example 1, except that the calcination temperature in step (5) of this embodiment is 600 ℃ and the calcination time is 4 h.

[0042] This embodiment also provides a biomass gasification adsorption-enhanced reforming hydrogen production catalyst prepared by the above preparation method and its application. The application method is the same as that in Example 1. The experimental results, calculated by integration, show that the H2 yield of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst prepared in this embodiment is 676.76 mL / g.

[0043] Example 4 This embodiment provides a method for preparing a biomass gasification adsorption-enhanced reforming hydrogen production catalyst, which is basically the same as that in Example 1, except that the calcination temperature in step (5) of this embodiment is 700 ℃ and the calcination time is 3 h.

[0044] This embodiment also provides a biomass gasification adsorption-enhanced reforming hydrogen production catalyst prepared by the above preparation method and its application. The application method is the same as that in Example 1. The experimental results, calculated by integration, show that the H2 yield of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst prepared in this embodiment is 645.26 mL / g.

[0045] Those skilled in the art can also adjust the corresponding preparation parameters under preferred conditions according to actual conditions or needs, and all can achieve the corresponding objectives of the present invention.

[0046] Example 5 The difference between this embodiment and Example 1 lies in the metal loading ratio. In this embodiment, Ni and Fe are loaded at a mass ratio of 1:1, calcined at 800 ℃ for 2 h to complete the preparation of the corresponding catalyst, and its performance is tested using the same application method.

[0047] In this embodiment, the H2 yield at this ratio was only 105.90 mL / g during the pyrolysis section test, significantly lower than the performance of Example 1 (150.27 mL / g). Due to the poor performance of the ratio, no subsequent gasification experiments were conducted. This demonstrates that the optimized ratio designed in this invention (e.g., Ni:Fe=4:1) has significant advantages in inducing bimetallic synergistic effects.

[0048] Comparative Example 1 Following the preparation method of Example 1, this comparative example replaced the auxiliary Fe with an equal mass of Mo, and prepared the corresponding catalyst under calcination conditions of 700 °C / 3 h. Its performance was then tested using the same application method.

[0049] In this comparative example, the H2 yield in the gasification stage was only 558.83 mL / g, which is lower than the catalytic reforming performance of the catalyst with Fe as the promoter under the same calcination conditions (H2 yield 645.26 mL / g). The above calculations demonstrate that when Fe promoter is used in conjunction with the active phase Ni and CeO2 support for enhanced reforming, its synergistic hydrogen production capacity far exceeds that of conventional transition metal Mo.

[0050] Comparative Example 2 The application of this comparative example is basically the same as that of Example 1, except that only eggshells are used as adsorbents, i.e., the blank group without catalyst.

[0051] The catalyst preparation parameters of Examples 1-4 and Comparative Example 1 are summarized in Table 1.

[0052] Table 1: Summary Table of Catalyst Preparation Parameters

[0053] The results of the performance evaluation of biomass adsorption-enhanced reforming hydrogen production in Examples 1-4 and Comparative Examples 1 and 2 are summarized in Table 2.

[0054] Table 2: Summary Table of Performance Evaluation of Biomass Adsorption-Enhanced Reforming Hydrogen Production

[0055] In Table 2, the hydrogen production improvement rate is calculated based on the H2 integral area of ​​Comparative Example 2 (with only eggshells as adsorbent).

[0056] Based on the above test results, compared with Comparative Example 2, which relied solely on calcium-based adsorbents to capture CO2, Example 1 of this invention, by introducing a CeO2-Ni-Fe catalyst prepared through a specific process, further increased the green hydrogen yield from 592.03 mL / g to 719.56 mL / g under the same adsorption enhancement conditions, achieving a net increase of 21.5%. It is noteworthy that while achieving the highest hydrogen production, Example 1 also saw a decrease in CH4 yield to 76.37 mL / g, significantly lower than other temperature groups and the blank control group. This further confirms that Example 1 possesses the strongest tar cracking and light hydrocarbon reforming capabilities, maximizing the conversion of intermediate products in the biomass conversion process into green hydrogen.

[0057] Observing the data trends of Examples 1-4, as the calcination temperature increased from 400 °C to 500 °C while satisfying the temperature-time complementary correlation formula, the hydrogen production showed a significant upward trend; when the temperature continued to rise to 600 °C and 700 °C, the hydrogen production activity began to decline. This indicates that calcination at 500 °C for 5 h is the optimal window for activation of this catalytic system. Under this condition, the catalyst maintains highly dispersed active metal microcrystals and enhances the oxygen storage and release capacity of CeO2 through appropriate lattice defects, thereby achieving the peak hydrogen production abundance.

[0058] The microstructure of the catalysts prepared in Examples 1 and 5 was observed using a scanning electron microscope. According to... Figure 2 (a) and (b) clearly show that the catalyst obtained by calcination at 500 °C for 5 h in Example 1 exhibits a nanoparticle stacked state, with a loose structure and a large specific surface area; while the catalyst obtained by calcination at 800 °C for 2 h in Example 5 shows obvious grain growth and sintering phenomena. The catalyst of Example 1 was further characterized by transmission electron microscopy, based on... Figure 3 The results show that uniformly sized nano-Ni-Fe metal particles are uniformly loaded on the bulk CeO2 support by epitaxial growth or semi-embedding, confirming the strong metal-support interaction of the present invention.

[0059] Comparing Example 4 with Comparative Example 1, it can be seen that under the same calcination regime of 700 °C, the hydrogen production efficiency of the Ni-Fe system is significantly better than that of the conventional Ni-Mo system. The Ni-Mo group (558.83 mL / g) is even lower than the benchmark group (592.03 mL / g). The reason for this may be that the synergistic ability of the Mo additive with CeO2 is limited at this temperature, and it may interfere with the kinetics of the adsorption centers. In contrast, the present invention, by introducing the Fe additive, effectively modulates the electronic structure of the active sites, exhibiting extremely strong reforming activity.

[0060] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for preparing a biomass gasification adsorption-enhanced reforming hydrogen production catalyst, characterized in that, Includes the following steps: (1) Cerium dioxide is ground to obtain a powdered carrier; (2) Dissolve the nickel-containing active phase precursor and the iron-containing co-catalytic precursor in water to obtain a mixed salt solution; (3) Add the powdered carrier to the mixed salt solution and mix to obtain a solid-liquid mixture; (4) The solid-liquid mixture is dried and ground to obtain precursor powder; (5) The precursor powder was calcined under an inert atmosphere to obtain a biomass gasification adsorption-enhanced reforming hydrogen production catalyst.

2. The preparation method of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst according to claim 1, characterized in that: In step (2), the active phase precursor containing nickel includes soluble nickel salts; the co-catalytic precursor containing iron includes soluble iron salts.

3. The preparation method of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst according to claim 2, characterized in that: The soluble nickel salt includes one or both of nickel nitrate and nickel acetate; the soluble iron salt includes one or both of ferric nitrate and ferric acetate.

4. The preparation method of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst according to claim 1, characterized in that: In step (3), the mixing includes stirring at room temperature for 2-4 h; in step (4), the drying includes treatment at 80-105 °C for 8-12 h.

5. The preparation method of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst according to claim 1, characterized in that, In step (5), the calcination temperature and calcination time of the calcination treatment satisfy a complementary relationship, and the calcination temperature and calcination time satisfy the following relationship: T ×0.01+ t =10 in, T The calcination temperature is ℃; t The calcination time is in hours (h). T The value range is 400~700℃. t The value range is 3~6 h.

6. The preparation method of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst according to claim 1, characterized in that: In step (5), the biomass gasification adsorption-enhanced reforming hydrogen production catalyst includes 70 wt.%~90 wt.% cerium dioxide and the balance active material; the active material includes nickel and iron, and the mass ratio of nickel to iron is 3:2~4:

1.

7. A biomass gasification adsorption-enhanced reforming hydrogen production catalyst, characterized in that: It is prepared by any one of the preparation methods described in claims 1 to 6.

8. The application of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst as described in claim 7, characterized in that, include: As a catalyst, it is used in conjunction with calcium-based adsorbents for biomass gasification adsorption-enhanced reforming to produce hydrogen.

9. The application of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst according to claim 8, characterized in that, The biomass gasification adsorption-enhanced reforming hydrogen production adopts a segmented reaction process, including: Biomass pyrolysis / gasification section: Pretreated biomass is pyrolyzed at 700~900 ℃ and gasified in a steam atmosphere to produce syngas containing hydrogen, carbon monoxide, carbon dioxide and methane. Adsorption section: filled with calcium-based adsorption material with carbon dioxide adsorption function, used to capture carbon dioxide generated by the reaction in situ at 800~1000 ℃; Reforming section: filled with biomass gasification adsorption-enhanced reforming hydrogen production catalyst, used to catalytically reform syngas at 500~700 ℃ to obtain hydrogen-rich syngas; The aforementioned calcium-based adsorbent and biomass gasification adsorption-enhanced reforming hydrogen production catalyst are arranged in layers or placed in different temperature control zones within the reactor.

10. The application of the biomass gasification adsorption-enhanced reforming hydrogen production catalyst according to claim 9, characterized in that, In the segmented reaction process, the mass percentage of materials in each segment is as follows: biomass 40%~60%, calcium-based adsorbent material 20%~30%, and biomass gasification adsorption-enhanced reforming hydrogen production catalyst 20%~30%.

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