Method of fluidized circulating reforming of blast furnace gas

Abstract

The application discloses a method for fluidized circulating reforming of blast furnace gas, and constructs a fluidized online circulating reforming process through a circulating design of a double fluidized furnace, expands a contact area of the blast furnace gas and a reforming agent based on a fluidized reaction mode, reduces heat and mass transfer resistance, effectively improves carbon dioxide reforming conversion efficiency, simultaneously, based on online circulation of the reforming agent, frequent switching of operating conditions is not needed, the process is simple and controllable, a flow process is short, operation and maintenance costs are low, continuous and stable operation can be realized, gas reforming efficiency is high, quality upgrading of the blast furnace gas can be effectively realized, the method is suitable for treatment of large-scale industrial blast furnace gas, can significantly improve energy utilization efficiency of a steel enterprise, and has good industrial application prospect and economic benefits.

Description

Technical Field

[0001] This invention relates to the fluidization treatment of blast furnace gas, specifically to a method for fluidized circulating reforming of blast furnace gas, belonging to the technical field of fluidization treatment of blast furnace gas. Background Technology

[0002] Blast furnace gas is a core by-product of the blast furnace ironmaking process in the iron and steel metallurgical industry, and is one of the largest industrial waste gases produced in the steel industry. During blast furnace ironmaking, coke, pulverized coal, and iron ore undergo an oxidation-reduction reaction inside the blast furnace. While the iron ore is reduced to pig iron, a large amount of low-calorific-value blast furnace gas is continuously generated. In industrial production, 1500-2000 m³ of blast furnace gas can be generated for every ton of pig iron smelted. 3 Blast furnace gas: The total annual output of blast furnace gas in my country's steel industry exceeds 1.4 trillion Nm³. 3 Blast furnace gas has immense value for resource utilization and low-carbon transformation. Its composition is complex, mainly containing nitrogen, carbon monoxide, carbon dioxide, and hydrogen, with CO2 accounting for 18% to 25% by volume. It also contains trace impurities such as dust, fluidized bed material, nitrogen oxides, and heavy metals. The gas has a relatively low overall calorific value, and its composition fluctuates easily with blast furnace operating conditions. Direct emission would cause serious carbon pollution and energy waste. Therefore, efficient treatment and resource utilization of CO2 in blast furnace gas is a core and crucial step for the steel industry to achieve its dual-carbon goals and promote energy conservation, emission reduction, and the development of a circular economy.

[0003] Currently, the mainstream methods for treating CO2 from blast furnace gas in the industry are carbon capture and separation, chemical reforming and conversion, and CCUS (Carbon Capture and Sequestration System) storage, resulting in various industrial applications and experimental technical solutions. One type is physical capture technology, mainly including pressure swing adsorption (PSA), temperature swing adsorption, and membrane separation processes. Among these, pressure swing adsorption technology is the most widely used. This technology utilizes the difference in adsorption capacity of the adsorbent for CO2 and other components in the gas, achieving CO2 separation and purification through alternating pressure changes. It often employs a two-stage PSA coupled with catalytic conversion, which can effectively improve the carbon component recovery rate. The purified CO2 can be used for liquefaction and export, industrial raw material supply, and other scenarios. Membrane separation technology relies on selective permeation membranes, achieving CO2 sieving based on the difference in gas molecule permeation rates, and features compact equipment and convenient operation. Secondly, there is chemical absorption treatment technology, which is the mainstream process for industrial-scale CO2 removal. It involves a reversible chemical reaction between absorbents such as alkanolamines and CO2 in blast furnace gas, achieving efficient CO2 capture. Subsequent heating and depressurization regenerate the absorbent and purify the CO2. The purified high-purity CO2 can be applied to steelmaking auxiliary material substitution, chemical synthesis raw materials, and oil and gas displacement. Thirdly, there is resource conversion and utilization technology. Relying on thermochemistry, bio-fermentation, catalytic synthesis, and fixed-bed chemical chain conversion pathways, it synergistically converts CO2 in blast furnace gas with components such as CO and H2 to produce high-value-added chemicals such as green methanol, formic acid, and carbonates. Currently, a demonstration project for green methanol production from blast furnace gas has been established in China, realizing the industrialization of waste gas resource utilization. Fourthly, there is carbon sequestration (CCS) technology. This technology compresses and liquefies the captured and purified CO2, achieving permanent carbon sequestration through geological or marine methods, completely eliminating carbon emissions. It is often coupled with carbon capture technology to form a complete CCUS treatment system.

[0004] While existing blast furnace gas CO2 treatment technologies have achieved industrial-scale implementation and application, numerous technical shortcomings and application pain points still exist in actual production conditions, hindering the promotion and application of low-carbon, high-efficiency, and low-cost treatment of blast furnace gas. Physical adsorption processes are weak in resisting operating condition fluctuations, impurities easily cause adsorbent failure, and maintenance costs are high; membrane separation struggles to balance treatment throughput and separation accuracy, membranes are prone to corrosion and blockage, and service life is short. Chemical absorption processes have high regeneration energy consumption, absorbents are easily degraded and lost, and equipment is easily corroded, generating secondary pollutants. Reforming and conversion technologies suffer from complex processes, low conversion efficiency, and poor economic efficiency. Specifically, fixed-bed chemical looping conversion has limited gas-solid contact area, resulting in low reaction conversion efficiency; reaction control lags under operating condition fluctuations, leading to poor product stability; impurities easily accumulate, causing bed blockage and increased system pressure drop; poor bed heat dissipation easily leads to catalyst sintering and carbon buildup, and online regeneration and replacement are impossible, resulting in significant downtime losses; high internal heat and mass transfer resistance, and localized high temperatures easily promote side reactions; limited processing capacity of single units, and high costs for large-scale expansion. Meanwhile, the low calorific value and complex composition of blast furnace gas lead to poor reaction stability in conversion pathways such as catalytic synthesis and bio-fermentation, resulting in generally low CO2 conversion rates and numerous byproducts. The overall resource-based conversion process is lengthy, requires numerous supporting equipment, and incurs high investment costs, making large-scale replication of demonstration projects difficult. Most high-value-added product conversion processes have not yet achieved large-scale industrialization, making it difficult to balance resource utilization and economic benefits. Carbon sequestration is significantly limited by geological conditions, posing a risk of leakage. The entire system is costly and energy-intensive to operate, has poor adaptability, and lacks a universal pretreatment system, making it susceptible to interference from impurities that can cause instability in the entire reforming system. Summary of the Invention

[0005] To address the problems of low reforming efficiency and long process length in existing blast furnace gas reforming methods, this invention provides a fluidized bed circulating reforming method for blast furnace gas. This method utilizes a dual fluidized bed furnace design to achieve the recycling and reuse of the reforming agent. By relying on the fluidized bed reaction, the contact area between the blast furnace gas and the reforming agent is expanded, reducing heat and mass transfer resistance and effectively improving the carbon dioxide reforming conversion efficiency. Simultaneously, online recycling and regeneration of the reforming agent can be achieved, preventing catalyst deactivation due to carbon buildup and sintering. This method is better suited to the complex compositional fluctuations of blast furnace gas and reduces operating and maintenance costs.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for fluidized bed reforming of blast furnace gas, the method being described below:

[0008] S1: Blast furnace gas is fed into the reforming fluidized bed as fluidizing gas. At the same time, a reducing reforming agent is added to the reforming fluidized bed to react with the blast furnace gas in a fluidized bed reforming reaction. After separation by the first gas-solid separation unit, reformed gas and oxidized reforming agent are obtained.

[0009] S2: The oxidized reforming agent is added to the fluidized bed reformer, and simultaneously, reducing fluidizing gas is introduced into the fluidized bed reformer to react with the oxidized reforming agent. After separation by the second gas-solid separation unit, syngas and the reduced reforming agent are obtained. The reduced reforming agent is returned to the fluidized bed reformer for recycling.

[0010] Preferably, the reforming fluidized bed includes, from bottom to top, a gas inlet chamber, a reforming mixing chamber, and a reforming fluidization chamber connected in series. A perforated gas distribution plate is provided between the gas inlet chamber and the reforming mixing chamber. Blast furnace gas is input from the fluidizing gas inlet at the bottom of the gas inlet chamber, and reducing reforming agent is added from the feed inlet on the side wall of the reforming mixing chamber. The reformed gas and oxidizing reforming agent flow upward and are discharged from the discharge outlet at the top of the reforming fluidized bed.

[0011] Preferably, a first heating mechanism is provided on the furnace wall of the reforming fluidized bed furnace. The temperature of the fluidized reforming reaction inside the reforming fluidized bed furnace is adjusted to 700~1000℃, preferably 750~900℃, by the first heating mechanism. Preferably, the first heating mechanism is an electric heating plate, a microwave heater, or a gas burner.

[0012] Preferably, the bottom of the inner cavity of the fluidized bed furnace is divided into a reduction inlet chamber by a porous reducing gas distribution plate. The reducing fluidizing gas is input from the fluidizing gas inlet at the bottom of the reduction inlet chamber, the oxidized reforming agent is added from the feed port on the top or side wall of the fluidized bed furnace, and the syngas and the reducing reforming agent are discharged from the discharge port on the upper part of the side wall of the fluidized bed furnace.

[0013] Preferably, a second heating mechanism is provided on the furnace wall of the fluidized bed reactor. The temperature of the fluidized bed reaction inside the fluidized bed reactor is adjusted to 550~850℃, preferably 650~800℃, by the second heating mechanism. Preferably, the second heating mechanism is an electric heating plate, a microwave heater, or a gas burner.

[0014] Preferably, in step S1, the flow velocity of blast furnace gas in the lower part of the reforming fluidized bed (i.e., within the reforming mixing chamber) is 0.3~1 m / s, preferably 0.5~0.8 m / s. The flow velocity in the upper part of the reforming fluidized bed (i.e., within the reforming fluidization chamber) is 4~10 m / s, preferably 6~8 m / s. The mixing ratio of the reducing reforming agent to the blast furnace gas is 2~6 kg / Nm³. 3 The preferred concentration is 3~4 kg / Nm³. 3 The residence time of the reduced reforming agent in the reforming mixing chamber is 120~480s, preferably 180~300s.

[0015] Preferably, in step S1, the first gas-solid separation unit includes a first cyclone separator and a first return feeder disposed at the bottom of the first cyclone separator. The reformed gas is discharged from the exhaust port at the top of the first cyclone separator, and the oxidized reforming agent is discharged to the conversion fluidized bed furnace via the first return feeder at the bottom of the first cyclone separator.

[0016] Preferably, in step S2, the flow rate of the reducing fluidizing gas in the reforming fluidizing furnace is 0.5~1 m / s, more preferably 0.6~0.8 m / s. The mixing ratio of the oxidized reforming agent to the reducing fluidizing gas is 2~6 kg / Nm³. 3 The preferred concentration is 3~4 kg / Nm³. 3 The residence time of the oxidized reforming agent in the conversion fluidized bed furnace is 240~600s, preferably 300~480s.

[0017] Preferably, in step S2, the second gas-solid separation unit includes a second cyclone separator and a second return feeder disposed at the bottom of the second cyclone separator. Syngas is discharged from the exhaust port at the top of the second cyclone separator, and the reducing reforming agent is discharged to the reforming fluidized furnace via the second return feeder at the bottom of the second cyclone separator.

[0018] Preferably, the reducing fluidizing gas is methane and / or natural gas.

[0019] Preferably, the reforming agent is LaMn. y Fe 1-x-y Ni x O3, wherein: 0≤x≤0.5, 0.05≤y≤0.4, preferably 0.1≤x≤0.4, 0.1≤y≤0.3, more preferably 0.2≤x≤0.3, 0.15≤y≤0.25.

[0020] Preferably, the particle size of the reforming agent is 120~500μm, and more preferably 150~400μm.

[0021] Preferably, the reforming agent is prepared by complexation gelation using lanthanum salt, manganese salt, iron salt, and nickel salt as raw materials: first, lanthanum salt, manganese salt, iron salt, nickel salt, and complexing agent are mixed and dissolved in water according to the stoichiometric ratio of each element in the target reforming agent, then heated and stirred to form a gel, and finally the target reforming agent is obtained after drying, calcination, and crushing.

[0022] Preferably, the lanthanum salt is selected from at least one of lanthanum nitrate, lanthanum chloride, lanthanum bromide, lanthanum sulfate, and lanthanum acetate. The manganese salt is selected from at least one of manganese nitrate, manganese chloride, manganese bromide, manganese sulfate, and manganese acetate. The iron salt is selected from at least one of ferric nitrate, ferric chloride, ferric bromide, ferric sulfate, ferric acetate, ferrous nitrate, ferrous chloride, ferrous bromide, ferrous sulfate, and ferrous acetate. The nickel salt is selected from at least one of nickel nitrate, nickel chloride, nickel bromide, nickel sulfate, and nickel acetate. The complexing agent is citric acid.

[0023] Preferably, the heating and stirring temperature is 60~100℃, and the heating and stirring rate is 200~600 rpm. The drying temperature is 100~150℃, and the drying time is 5~24h. The calcination treatment is as follows: first calcination at 200~500℃ for 1~8h, and then calcination at 1000~1400℃ for 1~8h. The molar amount of the complexing agent is 1~5 times the total molar amount of lanthanum, manganese, iron, and nickel ions.

[0024] In existing technologies, using fixed beds to process blast furnace gas has several drawbacks. First, it results in low gas-solid contact efficiency and high resistance to heat and mass transfer, making it difficult to fully utilize the reactivity of the reforming agent and leading to low overall carbon dioxide conversion efficiency. Second, fixed beds are prone to carbon buildup and blockage, causing a continuous increase in system pressure drop. Poor heat dissipation within the bed can easily lead to sintering and deactivation of the reforming agent. Furthermore, online regeneration and replacement of the reforming agent are not possible, requiring shutdown for processing, which significantly increases production losses and maintenance costs. Additionally, fixed bed units have limited processing capacity, resulting in high overall investment costs for large-scale expansion. They also struggle to adapt to the fluctuating composition of blast furnace gas under varying production conditions, leading to delayed reaction control and difficulty in ensuring the stability of reformed products. This method aims to achieve fluidized reforming of blast furnace gas in a reforming fluidized bed furnace. Utilizing the fluidized bed reaction mechanism, it expands the contact area between the blast furnace gas and the reforming agent, reducing heat and mass transfer resistance. This efficiently converts CO2 in the blast furnace gas into CO, significantly increasing the calorific value and the proportion of usable carbon components. The oxidized reforming agent then enters a conversion fluidized bed furnace for reduction and regeneration. The regenerated reforming agent is returned to the reforming fluidized bed furnace for recycling. The entire process operates continuously without the need for shutdown to replace the regenerated catalyst. It boasts high processing efficiency, easily controllable reaction conditions, and low operation and maintenance costs, making it suitable for large-scale continuous industrial production needs. It can effectively improve the resource utilization of blast furnace gas, reduce carbon emissions, and meet the application requirements of dual-carbon transformation in the steel industry.

[0025] In this invention, the fluidized reforming of blast furnace gas is mainly carried out in a specially designed reforming fluidized furnace. This reforming fluidized furnace is divided into four sections from bottom to top: gas inlet, mixing, fluidized reaction, and discharge. The bottom of the gas inlet section is equipped with a blast furnace gas inlet, and the top of the gas inlet section is equipped with a flow equalization air distribution plate to ensure that the blast furnace gas flow rate entering the reaction section is uniform and the flow pattern is stable, while preventing the reforming agent from leaking down. The side wall of the mixing section is equipped with a reducing state reforming agent inlet for adding and circulating the reforming agent. The side wall of the fluidized reaction section is equipped with a temperature regulating heating component (i.e., the first heating mechanism) to regulate the reaction temperature in the reaction section and ensure the efficient conversion of CO2 in the furnace. The discharge section is equipped with a first gas-solid separation structure to achieve gas-solid separation between the reformed gas and the oxidized state reforming agent.

[0026] In this invention, the regeneration of the oxidized reforming agent is carried out in a fluidized bed reactor. The bottom of the fluidized bed reactor is also equipped with a reducing fluidizing gas inlet chamber, and a reducing gas uniformity distribution screen is arranged at the top of the chamber to ensure uniform flow rate and stable flow pattern when the fluidizing gas enters the reaction chamber, avoiding localized insufficient fluidization that could affect the reduction and regeneration of the reforming agent. An oxidized reforming agent inlet is provided on the side wall of the fluidized bed reactor to receive oxidized reforming agent discharged from the reforming fluidized bed reactor or to add fresh oxidized reforming agent. A second temperature-regulating heating component (i.e., a second heating mechanism) is arranged on the outer side of the furnace wall, which can independently adjust the reaction temperature inside the fluidized bed reactor according to the reduction and regeneration requirements, matching the reduction kinetics requirements of the oxidized reforming agent. A second gas-solid separation structure is provided at the top of the furnace body to achieve efficient separation of the generated syngas and the reduced reforming agent. The separated syngas is discharged and collected for utilization, while the reduced reforming agent is transported back to the reforming fluidized bed reactor through a return structure, completing the recycling of the reforming agent within the entire system.

[0027] In the dual fluidized bed furnace system of this invention, different gas streams (blast furnace gas and reducing gas) flow separately, avoiding mixing and interference between the two streams. Simultaneously, the reforming agent circulates continuously between the two reactors, completing the reforming reaction and reduction regeneration. This ensures the purity of each reaction stream, improves the convenience of subsequent product collection and utilization, and enables continuous operation of the reaction process without downtime for reforming agent regeneration or replacement, effectively reducing losses caused by production stoppages and lowering overall operation and maintenance costs. The fluidized bed reaction mode significantly increases the contact area between the gas and solid phases, reduces heat and mass transfer resistance, fully utilizes the reactivity of the reforming agent, effectively improves the CO2 conversion efficiency in blast furnace gas, and ensures uniform temperature distribution within the furnace under fluidized bed conditions. This avoids side reactions caused by localized high temperatures and the problem of reforming agent sintering and carbon buildup, extending the service life of the reforming agent and improving the stability of the reaction process. It better adapts to the fluctuating characteristics of blast furnace gas composition under production conditions, and allows for real-time adjustment of reaction parameters to ensure stable quality of the reformed products.

[0028] In the reforming fluidized bed furnace of the present invention, the reduced reforming agent mainly comes from the reforming agent that has been pre-reduced in the conversion fluidized bed furnace (it should be noted that the initial state of the reforming agent is the oxidized state, and the reduction process can be represented as: The reducing reforming agent in the reforming fluidized bed will steal an oxygen atom from CO2 and be converted into an oxidized state. The CO generated in the reaction is mixed with the blast furnace gas to become reformed gas, increasing the overall calorific value. This process not only converts CO2 into a usable combustible component but also transforms the reforming agent from a reduced state to an oxidized state, completing one reaction cycle. After gas-solid separation, the oxidized reforming agent is sent to a fluidized bed for further reduction and regeneration, maintaining the continuous and stable operation of the entire reaction system. Through this oxygen transfer cycle, CO2 in the blast furnace gas can be continuously consumed and directionally converted into combustible CO components, increasing the overall calorific value of the blast furnace gas and achieving effective carbon resource recovery and utilization, thus reducing carbon emissions. The entire process requires no additional oxidant; continuous conversion is achieved solely through the circulation of the reforming agent between two fluidized beds. The process is simple, highly efficient, and suitable for large-scale continuous industrial production.

[0029] In this invention, the blast furnace gas fed into the reforming fluidized bed can also be pre-treated (not a necessary process), generally by dust removal to remove mixed dust and heavy metal impurities, reduce the negative impact of impurities on the activity of the reforming agent, and extend the service life of the reforming agent. The pre-treatment can also include deacidification, dehumidification and other treatment processes according to actual production needs, to further reduce the interference of impurities on the reforming reaction and ensure the continuous and stable operation of the reforming process.

[0030] In this invention, the online, short-process, and efficient treatment of blast furnace gas is achieved through the circulation of a bifunctional reformer. This requires the reformer to have good oxygen migration capacity and a stable structure, and to be resistant to loss of active components and structural collapse during multiple redox cycles. The perovskite-structured composite metal oxide reformer selected in this invention fixes lanthanum at the A-site and doesp manganese, nickel, iron, and other active metals at the B-site. This ensures the stability of the framework structure and enhances the oxygen migration rate through the synergistic effect between different metals, thus ensuring the efficiency of oxygen transfer during the cycle. At the same time, the reformer with this structure has good anti-carbon deposition performance, maintains high reactivity after multiple cycles, has a long service life, and can meet the needs of long-term continuous industrial production.

[0031] In this invention, a bifunctional reformer with a special structure is used to perform alternating sub-reactions in two independent reactors, cleverly circumventing the limitations of thermodynamic equilibrium and achieving staged energy conversion and in-situ separation of products. The basic principle is as follows: First, the reformer is reduced in a fluidized bed reactor using a reducing gas (such as CH4 or natural gas). (The reduction reaction can be represented as:) Subsequently, the reduced reforming agent is fed into a reforming fluidized bed furnace to perform a cracking reaction on the CO2 in the coal gas (the cracking reaction can be represented as: It also extracts lattice oxygen from CO2 molecules, thereby selectively reducing CO2 to CO, while the reforming fluidized bed itself is re-oxidized to an oxidized state (MeO2). x The CO2 molecules are then returned to the fluidized bed for further reduction. This process essentially utilizes the "inhalation" and "exhalation" of oxygen in the reformer lattice to activate CO2 molecules and remove oxygen atoms.

[0032] In this invention, the reforming agent is prepared using the sol-gel method. Specifically, a mixed salt solution is prepared by mixing lanthanum salt, manganese salt, iron salt, and nickel salt in a specific molar ratio (e.g., the preferred ion molar ratio of lanthanum, manganese, iron, and nickel is 1:0.05~0.4:0.1~0.95:0~0.5, more preferably 1:0.1~0.3:0.3~0.8:0.1~0.4, and even more preferably 1:0.15~0.25:0.45~0.65:0.2~0.3). Citric acid or similar substances are added as complexing agents. The solution is first heated and stirred to form a gel, then dried and subjected to a two-step calcination (e.g., heat treatment at 200~500℃ for 1~8h, followed by heat treatment at 1000~1400℃ for 1~8h). This yields a reforming agent with high catalytic activity and stability. It should be noted that citric acid is used as a complexing agent (or chelating agent) in this invention because citric acid forms stable complexes with metal ions (lanthanum ions, manganese ions, iron ions, and nickel ions), preventing premature precipitation or segregation of metal ions in subsequent processes. This ensures that the metal elements can be uniformly mixed at the molecular level, which is beneficial for the formation of uniformly structured LaMn during subsequent calcination. y Fe 1-x-y Ni x O3 composite reforming agent; at the same time, citric acid, as an organic carbon source, will burn and decompose during calcination, and the generated gas can promote the formation of a porous structure in the reforming agent, thereby increasing the specific surface area of ​​the reforming agent and helping to improve the catalytic activity of the reforming agent.

[0033] In the sol-gel process of this invention, the purpose of employing a two-stage calcination process is to achieve the structural formation and optimization of the reforming agent in stages. The first stage of calcination is preferably a low-temperature calcination at 200-500°C. Its main purpose is to remove moisture, volatile organic compounds, and decomposing complexing agents (such as citric acid) from the gel precursor, avoiding structural breakage or defects in the reforming agent due to the rapid release of large amounts of gas during direct high-temperature calcination. Simultaneously, this stage allows the metal ions to undergo preliminary reactions, forming an amorphous or low-crystallinity precursor. The second stage of calcination is a high-temperature calcination at 1000-1400°C. This is a crucial stage for the formation of the perovskite crystal phase. At this high temperature, the metal ions gain sufficient energy for diffusion and rearrangement, gradually forming LaMn with a complete cubic or orthorhombic crystal structure. y Fe 1-x-y Ni x O3 perovskite oxide, and the higher calcination temperature helps to improve the crystallinity and structural order of the crystal, enhancing the thermal stability and mechanical strength of the reformer. Simultaneously, appropriate high temperatures can also promote the ordered arrangement of lattice oxygen and the formation and regulation of oxygen vacancies, ensuring the reformer has good redox properties. The combination of a two-step calcination process avoids the structural defects and compositional inhomogeneities that may result from a single high-temperature calcination step. Furthermore, precise control of the temperature and time at each stage allows for precise regulation of the reformer's crystal structure, specific surface area, pore structure, and active site distribution, thus ensuring the final reformer has excellent catalytic activity and stability. It should be noted that the reformer prepared by the two-stage calcination process exhibits excellent initial strength because the perovskite crystal structure itself possesses high structural stability. After high-temperature sintering, the grains are tightly bonded with few internal defects, resulting in excellent wear resistance during fluidization. This effectively reduces the breakage rate of the reformer during long-term cycling, extends its overall service life, and reduces material replenishment costs during production.

[0034] In the reforming agent of this invention, lanthanum is used as a perovskite-type composite oxide structure (LaMn). y Fe 1-x-y Ni x The A-site cation in lanthanum ion (ABO3) is a core element maintaining the stability of the perovskite crystal structure. The general formula for perovskite is ABO3, where the A-site is usually a large-radius rare earth or alkaline earth metal ion, such as lanthanum ion (La). 3+Lanthanum possesses a suitable ionic radius and a stable +3 oxidation state, enabling it to effectively occupy the A-site and form a stable cubic or orthorhombic crystal structure framework with oxygen ions. This stable crystal structure is the basis for the reformer to maintain structural integrity during subsequent high-temperature calcination and under catalytic reaction conditions (especially potentially high-temperature environments), avoiding the loss of active sites due to structural collapse or phase transition. Secondly, as an A-site ion, lanthanum's electronegativity significantly influences the electronic structure and oxygen species behavior of the entire perovskite oxide. The high electronegativity of lanthanum ions strongly attracts the electron cloud of oxygen ions, thereby affecting the bonding strength between B-site transition metal ions and oxygen ions. This influence can regulate the formation energy and mobility of oxygen vacancies in the reformer (oxygen vacancies are key active sites in CO2 reduction reactions, serving as centers for CO2 molecule adsorption and dissociation). The presence of lanthanum helps to form an appropriate amount of stable oxygen vacancies in the perovskite structure, especially when different valence states of transition metals (such as Mn, Fe, Ni) are introduced at the B-site. The stabilizing effect of lanthanum can promote valence state cycling among these transition metal ions (such as Fe). 3+ / Fe 2+ Ni 3+ / Ni 2+ Mn 4 + / Mn 3+ / Mn 2+ This leads to the generation of more active oxygen vacancies through redox reactions. Furthermore, the introduction of lanthanum helps improve the thermal stability and anti-sintering ability of the reformer. In the high-temperature calcination preparation process and possible high-temperature catalytic reactions, lanthanum oxides (such as La₂O₃) have high melting points and chemical stability, which can inhibit the agglomeration of reformer particles and the sintering of B-site active metal components, thus maintaining the reformer with a large specific surface area and abundant active sites, ensuring its catalytic performance stability during long-term operation. Simultaneously, the presence of lanthanum ions may also affect the catalytic activity of B-site transition metal ions through steric and electronic effects; the large ionic radius of lanthanum allows for the adjustment of the lattice parameters of the perovskite structure, providing a suitable coordination environment and crystal field strength for B-site metal ions, which may optimize the adsorption configuration and activation barrier of CO₂ molecules by the B-site metal; moreover, the interaction between lanthanum and the B-site metal may also promote the transfer of electrons between metal-oxygen bonds, accelerating the kinetics of redox reactions. In summary, lanthanum is not only a framework element for constructing and stabilizing the perovskite structure in the reformer of this invention, but also lays an important foundation for the reformer to exhibit excellent performance in the CO2-catalyzed CO production reaction through its comprehensive regulation of crystal structure, electronic properties, oxygen vacancy behavior and thermal stability.

[0035] In the reforming agent of this invention, iron, as the main constituent element at the B site, exhibits a wide range of valence states (e.g., Fe). 3+Fe 2+ Fe can even appear under specific conditions. 4+ This variability in valence state is key to its participation in redox reactions. In the process of CO2 reduction to CO, Fe ions can act as active centers, changing their valence state cyclically (…). Fe ions transfer electrons, promoting the adsorption, activation, and electron transfer processes of CO2 molecules. In other words, CO2 molecules can adsorb onto Fe ion sites, and Fe... 2+ Fe can donate electrons to CO2 molecules, enabling their reduction to CO. Simultaneously, the introduction of Fe helps regulate the lattice oxygen activity and oxygen vacancy concentration in the perovskite structure. The moderate bond energy between Fe and oxygen ions allows for a certain degree of fluidity of lattice oxygen during the reaction, which is crucial for CO2 activation and oxygen species migration. It should be noted that an appropriate Fe content can create more oxygen vacancies on the reformer surface and in the bulk phase. These vacancies not only serve as adsorption sites for CO2 molecules but also lower the activation energy barrier required for CO2 decomposition, thereby improving the catalytic activity. However, excessive Fe content may lead to overcrowding of metal ions in the perovskite structure, affecting lattice stability and the uniform distribution of oxygen vacancies, and may even induce the formation of impurity phases, thus reducing catalytic performance. Conversely, insufficient Fe content cannot provide enough active sites and is unlikely to effectively synergize with other B-site elements such as Mn and Ni, resulting in poor overall catalytic activity and selectivity. This invention achieves highly efficient catalysis of the CO2 reduction reaction by precisely controlling the proportion of Fe at the B site (i.e., the value of 1-xy, where 0≤x≤0.5, 0.05≤y≤0.4). This ensures that Fe provides sufficient catalytic sites as the main active component and synergistically optimizes the electronic structure and oxygen vacancy characteristics of the reformer with Mn and Ni elements. Therefore, in the LaMn of this invention... y Fe 1-x Ni x In the O3 system, precisely controlling the proportion of iron to ensure its synergistic effect with manganese and nickel is crucial for achieving high performance in the reformer. Furthermore, iron exhibits good stability within the perovskite structure, forming stable solid solutions with lanthanum and other B-site metals. This helps maintain the structural integrity of the reformer under high-temperature reaction conditions, reducing the loss and sintering of active components.

[0036] In the reformer of this invention, the addition of manganese has a good promoting effect on the cycle stability and anti-carbon deposition properties of the reformer during the CO2 cracking process. Firstly, manganese (Mn) also has a rich range of valence states (Mn... 2+ Mn 3+ Mn 4+This multi-valence characteristic makes it an excellent electron shuttle in reforming agents, capable of efficiently participating in electron transfer during redox reactions; that is, in the CO2 reduction reaction, Mn can participate through rapid valence state cycling (e.g., ...). Mn promotes electron transfer, providing a continuous electron supply for the activation of CO2 molecules, thereby accelerating reaction kinetics. Furthermore, the introduction of Mn helps stabilize the oxygen ion framework in the perovskite structure. This is because the strong bonding between Mn ions and oxygen ions enhances the rigidity of the crystal structure, suppressing lattice distortion and oxygen ion loss that may occur under high-temperature reaction conditions or during long-term operation, thus improving the structural stability and anti-aging properties of the reformer. Simultaneously, Mn can synergistically interact with Fe and Ni elements to jointly regulate the oxygen vacancy concentration and distribution of the catalyst. This is because the specific valence state and ionic radius of Mn can influence the local electronic environment of surrounding Fe and Ni ions, optimizing the geometry and electronic state of active sites, thus achieving an optimal balance between CO2 adsorption, activation, and CO desorption processes. Research has shown that controlling the Mn ratio within the range of 0.05≤y≤0.4 (preferably 0.1≤y≤0.3, more preferably 0.15≤y≤0.25) fully leverages its advantages in redox cycles, structural stability, and synergistic effects with other metal elements. This ensures that the reformer exhibits excellent catalytic activity and stability under medium- and low-temperature conditions, avoiding excessive lattice oxygen reactivity due to excessive Mn content, which could trigger side reactions or excessive oxidation of the reformer surface. It also prevents insufficient Mn content from effectively participating in electron transfer and structural stability, thus guaranteeing the optimal effect of Mn in improving the reformer's cycle stability and anti-carbon deposition performance. In other words, an appropriate Mn content can form a good multi-metal synergistic system with Fe and Ni at the B-site, effectively inhibiting the deposition of carbon species on the reformer surface during the reaction. This is because the presence of Mn promotes the activation and migration of adsorbed oxygen species on the surface, promptly oxidizing carbon precursors to CO or CO2 for removal, thereby maintaining the cleanliness of the active sites on the reformer surface and extending the reformer's lifespan. Meanwhile, the introduction of Mn can also regulate the acid-base properties of the reformer, optimize the adsorption strength of CO2 molecules, avoid the difficulty of product desorption caused by excessive adsorption or the insufficient activation caused by excessively weak adsorption, and further improve the selectivity and stability of the catalytic reaction.

[0037] In the reformer of this invention, nickel, as another important dopant element at the B site, can increase the lattice oxygen release rate of the reformer, thereby further improving the CO2 conversion rate. Nickel (Ni) also has a variable valence state (Ni... 2+ Ni 3+The introduction of Ni enables strong electronic interactions with elements such as Fe and Mn, further optimizing the electronic conductivity of the perovskite structure. These interactions further promote charge transfer on the reformer surface, accelerating electron transfer of CO2 molecules at active sites and thus improving CO2 activation efficiency. Furthermore, the introduction of Ni helps increase the oxygen vacancy concentration on the reformer surface. Because Ni ions have relatively weaker bonds with surrounding oxygen ions, they more easily lose oxygen atoms under reaction conditions to form oxygen vacancies. These newly created oxygen vacancies, combined with those generated by Fe and Mn sites, form more active centers, enhancing CO2 adsorption and activation capabilities. Simultaneously, the presence of Ni also improves the selectivity of the reformer for CO products. Studies show that Ni sites have a moderate adsorption energy for CO, promoting CO2 reduction to CO without causing excessive hydrogenation or deep reduction of CO to other byproducts, thus ensuring high CO selectivity while improving CO2 conversion. Studies have found that when the amount of Ni doping is controlled to be ≤0.5 (preferably 0.1≤x≤0.4, more preferably 0.2≤x≤0.3), it can form an optimal ratio with Fe and Mn elements at the B site. Utilizing the synergistic effect of these three elements, the overall catalytic performance of the reformer can be significantly improved. Specifically, appropriate Ni doping can optimize the surface electronic state of the reformer, lower the activation energy barrier of CO2 molecules, promote the adsorption and dissociation of CO2 at active sites, and accelerate the migration and release of lattice oxygen, providing sufficient oxygen vacancies and active oxygen species for the CO2 reduction reaction, thereby significantly improving the CO2 conversion rate and CO generation rate. It should be noted that excessive Ni doping may lead to an imbalance in the distribution of metal ions in the perovskite structure, causing lattice distortion or impurity phase formation, which in turn damages structural stability and the uniformity of active sites. Conversely, insufficient Ni doping makes it difficult to fully utilize its regulatory effect on electronic properties and its synergistic effect with Fe and Mn, resulting in insufficient improvement in lattice oxygen release rate and CO2 conversion rate. Therefore, precisely controlling the doping ratio of Ni to form a synergistic and complementary active center system with Fe and Mn at the B site is one of the key factors in achieving high activity, high selectivity and high stability of the reformer.

[0038] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0039] Firstly, the method of this invention adopts a fluidized bed reforming process, which allows for more thorough contact between the reforming agent and blast furnace gas, resulting in higher mass and heat transfer efficiency. Simultaneously, the reforming and regeneration reactions are carried out in separate reactors, enabling continuous and stable operation without frequent switching of operating conditions. The process is simple and controllable, with a short flow path, low cost, and high gas reforming efficiency. It is suitable for large-scale processing of industrial blast furnace gas, effectively upgrading blast furnace gas, improving the energy utilization efficiency of steel enterprises, and possessing promising industrial application prospects and economic benefits.

[0040] Secondly, this invention introduces three transition metal elements—Mn, Fe, and Ni—at the B-site of the perovskite structure and utilizes the electronic synergistic effect among them to precisely control the oxygen vacancy concentration, distribution, and lattice oxygen activity of the reformer. This allows the reformer to exhibit excellent catalytic activation ability for CO2 in blast furnace gas over a wide temperature range, with CO2 conversion rate and CO selectivity far exceeding those of conventional reformers. This effectively improves the calorific value utilization efficiency of blast furnace gas and is more suitable for large-scale industrial applications.

[0041] Thirdly, the present invention uses a two-stage step-by-step calcination process to prepare the reforming agent, which not only ensures the complete formation of the perovskite crystal phase, but also precisely controls the pore structure, specific surface area and active site distribution of the reforming agent. The resulting reforming agent has high crystallinity, stable structure, and excellent anti-wear and anti-sintering properties. During long-term fluidized bed cyclic reaction, the catalytic activity decreases slowly, the reforming agent has a low breakage loss rate, effectively extends the service life and reduces operating costs. Attached Figure Description

[0042] Figure 1 This is a process flow diagram of the present invention.

[0043] Figure 2 This is a simplified structural diagram of the process equipment of the present invention.

[0044] Reference numerals in the attached figures: 1: Reforming fluidized bed furnace; 101: Gas inlet chamber; 102: Reforming mixing chamber; 103: Reforming fluidization chamber; 104: Gas perforated air distribution plate; 2: Conversion fluidized bed furnace; 201: Reduction inlet chamber; 202: Reduction gas perforated air distribution plate; 3: First gas-solid separation unit; 301: First cyclone separator; 302: First return feeder; 4: Second gas-solid separation unit; 401: Second cyclone separator; 402: Second return feeder; 5: First heating mechanism; 6: Second heating mechanism. Detailed Implementation

[0045] The technical solution of the present invention will be illustrated below with examples. The scope of protection sought by the present invention includes, but is not limited to, the following embodiments.

[0046] Example 1

[0047] like Figure 1-2 As shown, a method for fluidized bed reforming of blast furnace gas is described below:

[0048] S1: Blast furnace gas is fed into reforming fluidizer 1 as fluidizing gas. At the same time, reducing reforming agent is added into reforming fluidizer 1 to react with blast furnace gas in fluidized reforming reaction. After separation by the first gas-solid separation unit 3, reformed gas and oxidized reforming agent are obtained.

[0049] S2: The oxidized reforming agent is added to the reforming fluidized bed furnace 2, and simultaneously, reducing fluidizing gas is introduced into the reforming fluidized bed furnace 2 to react with the oxidized reforming agent in a fluidized bed reforming reaction. After separation by the second gas-solid separation unit 4, syngas and the reduced reforming agent are obtained. The reduced reforming agent is returned to the reforming fluidized bed furnace 1 for recycling.

[0050] Example 2

[0051] The reforming fluidized bed 1 is repeated in Example 1, except that it comprises, from bottom to top, a gas inlet chamber 101, a reforming mixing chamber 102, and a reforming fluidization chamber 103 connected in series. A porous gas distribution plate 104 is provided between the gas inlet chamber 101 and the reforming mixing chamber 102. Blast furnace gas is input from the fluidizing gas inlet at the bottom of the gas inlet chamber 101, and reducing reforming agent is added from the feed port on the side wall of the reforming mixing chamber 102. The reformed gas and oxidizing reforming agent flow upward and are discharged from the discharge port at the top of the reforming fluidization chamber 103.

[0052] Example 3

[0053] Example 2 is repeated, except that a first heating mechanism 5 is provided on the furnace wall of the reforming fluidized bed furnace 1. The temperature of the fluidized reforming reaction inside the reforming fluidized bed furnace 1 is adjusted to 700~1000℃ by means of the first heating mechanism 5.

[0054] Example 4

[0055] Example 3 was repeated, except that the temperature of the fluidized reforming reaction in the reforming fluidized furnace 1 was adjusted to 750~900°C by the first heating mechanism 5.

[0056] Example 5

[0057] Example 4 is repeated, except that the first heating mechanism 5 is an electric heating plate.

[0058] Example 6

[0059] Example 5 is repeated, except that the first heating mechanism 5 is a microwave heater.

[0060] Example 7

[0061] Example 6 is repeated, except that the bottom of the inner cavity of the fluidized bed furnace 2 is separated by a reducing gas porous air distribution plate 202 to form a reducing gas inlet chamber 201. The reducing fluidizing gas is input from the fluidizing gas inlet at the bottom of the reducing gas inlet chamber 201, the oxidized reforming agent is added from the feed port on the top wall of the fluidized bed furnace 2, and the syngas and the reducing reforming agent are discharged from the discharge port on the upper side wall of the fluidized bed furnace 2.

[0062] Example 8

[0063] Example 7 is repeated, except that a second heating mechanism 6 is provided on the furnace wall of the fluidized bed reactor 2. The temperature of the fluidized bed reaction inside the fluidized bed reactor 2 is adjusted to 550~800℃ by the second heating mechanism 6.

[0064] Example 9

[0065] Example 8 was repeated, except that the temperature of the fluidized bed conversion reaction in the conversion fluidization furnace 2 was adjusted to 650~750°C by the second heating mechanism 6.

[0066] Example 10

[0067] Repeat Example 9, except that the second heating mechanism 6 is an electric heating plate.

[0068] Example 11

[0069] Example 10 is repeated, except that the second heating mechanism 6 is a microwave heater.

[0070] Example 12

[0071] Example 11 is repeated, except that in step S1, the flow velocity of blast furnace gas in the reforming mixing chamber 102 is 0.3~1 m / s, and the flow velocity in the reforming fluidization chamber 103 is 4~10 m / s. The mixing ratio of the reducing reforming agent to the blast furnace gas is 2~6 kg / Nm³. 3 .

[0072] Example 13

[0073] Repeat Example 12, except that in step S1, the first gas-solid separation unit 3 includes a first cyclone separator 301 and a first return feeder 302 disposed at the bottom of the first cyclone separator 301. The reformed gas is discharged from the exhaust port at the top of the first cyclone separator 301, and the oxidized reforming agent is discharged to the conversion fluidized bed furnace 2 via the first return feeder 302 at the bottom of the first cyclone separator 301.

[0074] Example 14

[0075] Example 13 is repeated, except that in step S2, the flow rate of the reducing fluidizing gas in the reforming fluidizing furnace 2 is 0.5~1 m / s. The mixing ratio of the oxidized reforming agent to the reducing fluidizing gas is 2~6 kg / Nm³. 3 .

[0076] Example 15

[0077] Repeat Example 14, except that in step S2, the second gas-solid separation unit 4 includes a second cyclone separator 401 and a second return feeder 402 disposed at the bottom of the second cyclone separator 401. Syngas is discharged from the exhaust port at the top of the second cyclone separator 401, and the reducing reforming agent is discharged to the reforming fluidized furnace 1 via the second return feeder 402 at the bottom of the second cyclone separator 401.

[0078] Example 16

[0079] Repeat Example 15, except that the reducing fluidizing gas is methane.

[0080] Example 17

[0081] Repeat Example 16, except that the reducing fluidizing gas is natural gas.

[0082] Example 18

[0083] Repeat Example 17, except that the reforming agent is LaMn. y Fe 1-x-y Ni x O3, where: 0≤x≤0.5, 0.05≤y≤0.4.

[0084] Example 19

[0085] Repeat Example 18, except that 0.1≤x≤0.4 and 0.1≤y≤0.3.

[0086] Example 20

[0087] Repeat Example 19, except that 0.2≤x≤0.3 and 0.15≤y≤0.25.

[0088] Example 21

[0089] Repeat Example 20, except that the particle size of the reforming agent is 120~500μm.

[0090] Example 22

[0091] Example 21 is repeated, except that the reforming agent is prepared by complexing gel method using lanthanum salt, manganese salt, iron salt and nickel salt as raw materials: first, lanthanum salt, manganese salt, iron salt and nickel salt and complexing agent are mixed and dissolved in water according to the stoichiometric ratio of each element in the target reforming agent, then heated and stirred to form a gel, and finally the target reforming agent is obtained after drying, calcination and crushing.

[0092] Example 23

[0093] Example 22 is repeated, except that the lanthanum salt is selected from at least one of lanthanum nitrate, lanthanum chloride, lanthanum bromide, lanthanum sulfate, and lanthanum acetate. The manganese salt is selected from at least one of manganese nitrate, manganese chloride, manganese bromide, manganese sulfate, and manganese acetate. The iron salt is selected from at least one of ferric nitrate, ferric chloride, ferric bromide, ferric sulfate, ferric acetate, ferrous nitrate, ferrous chloride, ferrous bromide, ferrous sulfate, and ferrous acetate. The nickel salt is selected from at least one of nickel nitrate, nickel chloride, nickel bromide, nickel sulfate, and nickel acetate. The complexing agent is citric acid.

[0094] Example 24

[0095] Repeat Example 23, except that the heating and stirring temperature is 60-100°C and the stirring rate is 200-600 rpm. The drying temperature is 100-150°C and the drying time is 5-24 hours. The calcination treatment is as follows: first calcination at 200-500°C for 1-8 hours, and then calcination at 1000-1400°C for 1-8 hours. The molar amount of the complexing agent is 1-5 times the total molar amount of lanthanum, manganese, iron, and nickel ions.

[0096] Preparation Example 1

[0097] Preparation of the reforming agent: according to the target reforming agent (LaMn) y Fe 1-x-y Ni x Based on the molar ratio of La, Mn, Fe, and Ni ions in O3, appropriate amounts of lanthanum nitrate, manganese nitrate, ferric nitrate, and nickel nitrate were dissolved in deionized water to obtain a mixed salt solution with a total metal salt mass concentration of approximately 25%. Anhydrous citric acid, based on 1.8 times the total molar amount of metal ions, was then added to the mixed salt solution and stirred with a glass rod until completely dissolved, yielding a clear, transparent, and precipitate-free precursor solution. A magnetic stir bar was then added to a beaker containing the precursor solution, and the mixture was transferred to a water bath magnetic stirrer. Stirring was started, and the mixture was heated to 80°C for a hydrothermal reaction for 4 hours to obtain a honey-like wet gel product. The magnetic stir bar was then removed, and the wet gel product was transferred to a forced-air drying oven and dried at 120°C for 12 hours to obtain a fibrous precursor. The fibrous precursor was then placed in a muffle furnace and heated at 400°C for 4 hours. The temperature was then increased to 1200°C at a rate of 4°C / min and calcined at this temperature for 4 hours. Finally, the calcined product was cooled and crushed to obtain a reforming agent with a particle size distribution of 150–300 mm. The structural formulas and numbering of the reforming agents with different molar ratios are shown in Table 1 below.

[0098] Table 1. Structural formulas and their numbers for different reforming agents

[0099]

[0100] Application Example 1

[0101] The temperature field inside the fluidized bed converter 2 is controlled at 750±10℃ using the second heating mechanism 6. Then, the oxidized reforming agent in the first return feeder 302 is added to the fluidized bed converter 2. Simultaneously, natural gas is introduced into the fluidized bed converter 2 as fluidizing gas through the reduction inlet chamber 201 and the reducing gas porous air distribution plate 202 (flow rate approximately 0.7 m / s, mixing ratio of oxidized reforming agent to natural gas approximately 4.5 kg / Nm³). 3 Natural gas comes into contact with oxidized reforming agent and undergoes a fluidized bed conversion reaction (the average residence time of oxidized reforming agent in the conversion fluidized bed furnace 2 is about 400s). After that, the gas-solid mixture enters the second cyclone separator 401 of the second gas-solid separation unit 4 for separation to obtain syngas and reduced reforming agent. Syngas is discharged from the exhaust port at the top of the second cyclone separator 401, and reduced reforming agent falls into the second return feeder 402 at the bottom of the second cyclone separator 401.

[0102] The temperature field of the reforming fluidization chamber 103 in the reforming fluidizing furnace 1 is controlled to be 950±10℃ by the first heating mechanism 5. Then, blast furnace gas (CO2 volume content of about 21%) is introduced into the reforming fluidizing furnace 1 through the gas inlet chamber 101 and the gas porous air distribution plate 104 as fluidizing gas (flow velocity of about 0.6m / s). At the same time, reducing reforming agent from the second return feeder 402 is added through the feed inlet of the reforming mixing chamber 102 (the mixing ratio of reducing reforming agent and blast furnace gas is about 4.5kg / Nm). 3 The reduced reforming agent has an average residence time of approximately 240 s in the reforming mixing chamber 102. Then, the reduced diameter design between the reforming mixing chamber 102 and the reforming fluidization chamber 103 increases the fluidizing gas velocity (approximately 0.7 m / s). The blast furnace gas carries the reduced reforming agent into the reforming fluidization chamber 103 for fluidized reforming reaction. Afterward, the gas-solid mixture enters the first cyclone separator 301 of the first gas-solid separation unit 3 for separation to obtain reformed gas and oxidized reforming agent. The reformed gas is discharged from the exhaust port at the top of the first cyclone separator 301, while the oxidized reforming agent falls into the first return feeder 302 at the bottom of the first cyclone separator 301 and is then returned to the reforming fluidized furnace 2 for recycling.

[0103] In this application example 1, the reforming agent used is CZJ-1 (i.e., LaMn). 0.2 Fe 0.8 After the system had been running stably for 0.5 hours, the conversion rate of CH4 in the natural gas in the reforming fluidized bed 2 was detected to be approximately 32.4%, and the conversion rate of CO2 in the blast furnace gas in the reforming fluidized bed 1 was approximately 94.1%. After the system had been running stably for 10 hours, the conversion rate of CH4 in the natural gas in the reforming fluidized bed 2 was detected to be approximately 33.2%, and the conversion rate of CO2 in the blast furnace gas in the reforming fluidized bed 1 was approximately 93.2%.

[0104] Application Example 2

[0105] Example 1 was repeated, except that reformer CZJ-1 was sequentially replaced with other reformers (CZJ-2 to CZJ-16). The CO2 and CH4 conversion under different reformer conditions was tested and is shown in Table 2 below.

[0106] Table 2 Comparison of CO2 and CH4 conversion rates under different reforming agent conditions

[0107]

[0108] It should be noted that the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the technical solution of the present invention.

Claims

1. A method for fluidized bed reforming of blast furnace gas, characterized in that: The method is as follows: S1: Blast furnace gas is fed into reforming fluidizer (1) as fluidizing gas. At the same time, reducing reforming agent is added into reforming fluidizer (1) to react with blast furnace gas in fluidized reforming reaction. After separation by the first gas-solid separation unit (3), reformed gas and oxidized reforming agent are obtained. S2: Add the oxidized reforming agent to the conversion fluidized furnace (2), and at the same time introduce reducing fluidized gas into the conversion fluidized furnace (2) to carry out fluidized conversion reaction with the oxidized reforming agent. After separation by the second gas-solid separation unit (4), syngas and reduced reforming agent are obtained. The reduced reforming agent is returned to the reforming fluidized furnace (1) for recycling.

2. The method according to claim 1, characterized in that: The reforming fluidized bed (1) includes, from bottom to top, a gas inlet chamber (101), a reforming mixing chamber (102), and a reforming fluidized bed (103) connected in series. A porous gas distribution plate (104) is provided between the gas inlet chamber (101) and the reforming mixing chamber (102). Blast furnace gas is input from the fluidizing gas inlet at the bottom of the gas inlet chamber (101), and reducing reforming agent is added from the feed port on the side wall of the reforming mixing chamber (102). The reforming gas and oxidizing reforming agent flow upward and are discharged from the discharge port at the top of the reforming fluidized bed (103).

3. The method according to claim 1 or 2, characterized in that: A first heating mechanism (5) is provided on the furnace wall of the reforming fluidized furnace (1); the temperature of the fluidized reforming reaction in the reforming fluidized furnace (1) is adjusted to 700~1000℃, preferably 750~900℃ by the first heating mechanism (5); preferably, the first heating mechanism (5) is an electric heating plate, a microwave heater or a gas burner.

4. The method according to any one of claims 1-3, characterized in that: The bottom of the inner cavity of the conversion fluidized furnace (2) is separated by a reducing gas porous air distribution plate (202) to form a reducing gas inlet chamber (201); reducing fluidized gas is input from the fluidized gas inlet at the bottom of the reducing gas inlet chamber (201), oxidized reforming agent is added from the feed port on the top or side wall of the conversion fluidized furnace (2), and syngas and reducing reforming agent are discharged from the discharge port on the upper side wall of the conversion fluidized furnace (2).

5. The method according to any one of claims 1-4, characterized in that: A second heating mechanism (6) is provided on the furnace wall of the conversion fluidized furnace (2); the temperature of the fluidized conversion reaction in the conversion fluidized furnace (2) is adjusted to 550~850℃, preferably 650~800℃ by the second heating mechanism (6); preferably, the second heating mechanism (6) is an electric heating plate, a microwave heater or a gas burner.

6. The method according to any one of claims 1-5, characterized in that: In step S1, the flow velocity of blast furnace gas in the lower part of the reforming fluidized bed (1) is 0.3~1m / s, preferably 0.5~0.8m / s; the flow velocity in the upper part of the reforming fluidized bed (1) is 4~10m / s, preferably 6~8m / s; and the mixing ratio of reducing reforming agent to blast furnace gas is 2~6kg / Nm³. 3 The preferred concentration is 3~4 kg / Nm³. 3 ; and / or In step S1, the first gas-solid separation unit (3) includes a first cyclone separator (301) and a first return feeder (302) disposed at the bottom of the first cyclone separator (301); the reformed gas is discharged from the exhaust port at the top of the first cyclone separator (301), and the oxidized reforming agent is discharged to the conversion fluidized furnace (2) via the first return feeder (302) at the bottom of the first cyclone separator (301).

7. The method according to any one of claims 1-6, characterized in that: In step S2, the flow rate of the reducing fluidizing gas in the reforming fluidizing furnace (2) is 0.5~1m / s, preferably 0.6~0.8m / s; the mixing ratio of the oxidized reforming agent to the reducing fluidizing gas is 2~6kg / Nm³. 3 The preferred concentration is 3~4 kg / Nm³. 3 ; and / or In step S2, the second gas-solid separation unit (4) includes a second cyclone separator (401) and a second return feeder (402) disposed at the bottom of the second cyclone separator (401); the syngas is discharged from the exhaust port at the top of the second cyclone separator (401), and the reducing reforming agent is discharged to the reforming fluidized furnace (1) via the second return feeder (402) at the bottom of the second cyclone separator (401); Preferably, the reducing fluidizing gas is methane and / or natural gas.

8. The method according to any one of claims 1-7, characterized in that: The reforming agent is LaMn. y Fe 1-x- y Ni x O3, wherein: 0≤x≤0.5, 0.05≤y≤0.4, preferably 0.1≤x≤0.4, 0.1≤y≤0.3, more preferably 0.2≤x≤0.3, 0.15≤y≤0.25; Preferably, the particle size of the reforming agent is 120~500μm, and more preferably 150~400μm.

9. The method according to claim 8, characterized in that: The reforming agent is prepared by complexing gel method using lanthanum salt, manganese salt, iron salt and nickel salt as raw materials: first, lanthanum salt, manganese salt, iron salt and nickel salt and complexing agent are mixed and dissolved in water according to the stoichiometric ratio of each element in the target reforming agent, then heated and stirred to form a gel, and finally the target reforming agent is obtained after drying, calcination and crushing. Preferably, the lanthanum salt is selected from at least one of lanthanum nitrate, lanthanum chloride, lanthanum bromide, lanthanum sulfate, and lanthanum acetate; the manganese salt is selected from at least one of manganese nitrate, manganese chloride, manganese bromide, manganese sulfate, and manganese acetate; the iron salt is selected from at least one of ferric nitrate, ferric chloride, ferric bromide, ferric sulfate, ferric acetate, ferrous nitrate, ferrous chloride, ferrous bromide, ferrous sulfate, and ferrous acetate; the nickel salt is selected from at least one of nickel nitrate, nickel chloride, nickel bromide, nickel sulfate, and nickel acetate; and the complexing agent is citric acid.

10. The method according to claim 9, characterized in that: The heating and stirring temperature is 60~100℃, and the heating and stirring rate is 200~600rpm; the drying temperature is 100~150℃, and the drying time is 5~24h; the calcination treatment is as follows: first calcining at 200~500℃ for 1~8h, and then calcining at 1000~1400℃ for 1~8h; the molar amount of the complexing agent is 1~5 times the total molar amount of lanthanum, manganese, iron, and nickel ions.

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