Nickel-cobalt bimetallic catalyst for waste ion exchange resin carbon dioxide gasification reforming and preparation method and application thereof
By leveraging the synergistic effect of Ni-Co bimetallic catalyst and ZrO2 support, the problems of activity bottleneck, selectivity, and stability in the carbon dioxide gasification process of waste ion exchange resin were solved, achieving a highly efficient and stable CO2 gasification reaction, improving the total yield of syngas and CO selectivity, and reducing energy consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-03
- Publication Date
- 2026-03-10
AI Technical Summary
Existing catalysts suffer from activity bottlenecks, insufficient selectivity control, and poor stability during the carbon dioxide gasification process of waste ion exchange resins. This results in high reaction temperatures, high energy consumption, low gasification efficiency, unsatisfactory syngas yield, and difficulty in achieving high CO selectivity and high stability.
By combining a Ni-Co bimetallic catalyst with a ZrO2 support, a Ni-Co synergistic catalytic system was constructed. The preparation process was optimized, and a two-stage fixed-bed gasification process was adopted to achieve high activity, selectivity and stability of the catalyst. By utilizing the high activity of Ni for hydrocarbon cracking and the potential advantage of Co for CO generation, combined with the strong interaction of ZrO2, CO2 activation was promoted and side reactions were suppressed.
It significantly improved the total molar yield of syngas, enhanced CO selectivity and reaction rate, reduced energy consumption, and strengthened the catalyst's resistance to sintering and carbon deposition, thus achieving a highly efficient and stable CO2 gasification process.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of solid waste resource treatment and catalysts, in particular to a bimetallic catalyst for carbon dioxide gasification reforming of waste ion exchange resin and a preparation method and application thereof. BACKGROUND
[0002] As an important chemical material, sulfonic acid type cation exchange resin is widely used in water treatment, catalytic synthesis, hydrometallurgy and other fields. The waste resin generated after its failure is classified as organic hazardous solid waste, which has the characteristics of large amount and high difficulty in treatment. The traditional landfill method not only occupies land resources, but also has long-term environmental risks of heavy metal or toxic organic matter leaching; and the direct incineration method is easy to produce secondary pollutants such as dioxin, SO X , NO X , and causes resource waste.
[0003] Thermo-chemical gasification technology is considered as a promising solid waste resource treatment method. This technology can convert carbon-containing solid waste into synthesis gas with main components of H2 and CO at high temperature, thereby realizing significant volume and mass reduction, complete harmless and efficient energy / material recovery. In particular, using CO2 as the gasification agent has double environmental benefits: on the one hand, it can utilize greenhouse gas CO2 as a resource, and on the other hand, it can effectively improve the yield and purity of CO in synthesis gas through the Boudouard reaction (C + CO2→ 2CO), which is of great significance for the subsequent preparation of high-value chemicals (such as methanol and Fischer-Tropsch synthesis fuel). However, the direct CO2 gasification reaction of waste ion exchange resin usually requires extremely high temperature (>900ºC) to effectively proceed, which has problems of high energy consumption, slow reaction rate and low gasification efficiency. The introduction of a suitable catalyst is the key to reducing the reaction activation energy, improving the reaction rate and target product yield, and optimizing the composition of synthesis gas.
[0004] At present, the catalysts for gasification of carbonaceous materials can be mainly divided into two categories: alkali metal / alkaline earth metal salts (such as K2CO3, CaO) and transition metals (such as Fe, Co, Ni). Among them, transition metals have become a research hotspot due to their excellent catalytic activity for C-C bond breaking and reforming reactions.
[0005] Among the numerous transition metals, nickel (Ni)-based catalysts are widely studied due to their relatively low cost and outstanding activity for methane reforming and tar cracking. They can be considered as the closest prior art to the present invention, and their preparation method usually adopts the "impregnation-calcination method". Specifically, an alumina (AI2O3), silica (SiO2) or zirconia (ZrO2) carrier is impregnated in a nickel nitrate (Ni(NO3)2·6H2O) aqueous solution, dried, and then calcined at 400-600°C in an air atmosphere for several hours to form a supported NiO catalyst. Some advanced schemes further introduce rare earth metals (such as Ce) as additives, or add a reduction step in a hydrogen atmosphere to reduce NiO to metallic Ni with higher catalytic activity.
[0006] However, catalyst systems based on a single transition metal (especially Ni) still have shortcomings when applied to waste resin CO2 gasification: 1. Single metal catalyst activity bottleneck and lack of synergistic effect: The closest prior art (such as Ni / ZrO2) has a certain activity, but its catalytic performance has reached the ceiling. Ni-based catalysts are good at breaking C-C bonds, but their catalytic ability for the Boudouard reaction (C + CO2→ 2CO) is not optimal; Co-based catalysts perform well in the Fischer-Tropsch synthesis component reaction, and may have unique advantages in CO adsorption and activation. A single Ni or Co cannot simultaneously possess multiple optimal catalytic functions, lacks intermetallic synergistic effects, and results in non-optimal reaction pathways, limiting further improvement in gasification efficiency and syngas yield.
[0007] 2. Insufficient ability to regulate product selectivity: Existing catalysts cannot precisely regulate product distribution. For example, Ni-based catalysts, while efficiently cracking large molecules, often have a high tendency to generate CH4; Fe-based catalysts may lead to more CO2. Existing technologies lack an effective means to significantly promote the Boudouard reaction while suppressing side reactions such as methanation, resulting in suboptimal selectivity of the target product CO and the need to improve syngas quality.
[0008] 3. Challenges in catalyst stability and deactivation resistance: In high-temperature and complex reaction environments, single metal catalysts are prone to sintering, resulting in a decrease in active sites, or to deactivation due to severe carbon deposition covering active sites. In particular, for complex systems such as waste resins that may contain impurities (such as sulfur), the tolerance and lifespan of existing catalysts remain a serious challenge for industrial applications.
[0009] Therefore, the treatment of waste ion exchange resin urgently needs to develop a new catalyst which can have high activity, high selectivity and high stability. SUMMARY
[0010] Based on the above in-depth analysis, the purpose of the present application is not only to provide a nickel-cobalt bimetallic catalyst for carbon dioxide gasification reforming of waste ion exchange resin, its preparation method and application, but also to solve the three core problems of "activity bottleneck", "selectivity regulation" and "stability" of the existing catalyst.
[0011] The present application aims to solve the following problems existing in the existing CO2 gasification technology of waste ion exchange resin: 1. Non-catalytic gasification reaction has high temperature, high energy consumption and low gasification efficiency, and the yield of synthesis gas is not ideal.
[0012] 2. When using a single metal catalyst (such as a single Ni, Fe or Co-based catalyst), the molar yield (mmol / g) of the target synthesis gas (H2 and CO) still has a large room for improvement, and the catalytic activity is not optimal.
[0013] 3. The existing catalyst has limited ability to regulate the distribution of gasification products (H2 / CO ratio), and it is difficult to obtain synthesis gas with high CO selectivity.
[0014] Specifically, the purpose of the technical solution of the present application is: 1. Breakthrough of activity bottleneck: provide a Ni-Co bimetallic catalyst, by constructing a Ni-Co synergistic catalytic system, realizing functional complementation, significantly reducing the reaction activation energy, improving the reaction rate, and ultimately greatly improving the total molar yield of synthesis gas.
[0015] 2. Realize accurate regulation: provide a catalyst that can preferentially catalyze the Boudouard reaction and inhibit side reactions, especially achieve very high CO selectivity, to obtain synthesis gas with controllable components and higher quality.
[0016] 3. Enhance stability: by optimizing the ZrO2 carrier and the optimized preparation and reduction process, a high-stability catalyst with stronger anti-sintering and anti-carbon deposition ability in the harsh environment of waste resin CO2 gasification is obtained.
[0017] In order to achieve the above purpose, the present application proposes the following technical solutions: The core of the present application is to provide a complete "catalyst-process" system solution. The system takes the 1Ni / 1Co-ZrO2 bimetallic catalyst designed by innovation as the core, matches the two-stage fixed bed gasification process, and jointly acts to realize the efficient and high-selectivity CO2 gasification of waste resin.
[0018] The first aspect of the present application provides a nickel-cobalt bimetallic catalyst for carbon dioxide gasification reforming of waste ion exchange resin, the bimetallic catalyst comprising a carrier and an active component, the carrier being a metal oxide or a composite or a doped body thereof with high specific surface area and good stability, the active component consisting of nickel and cobalt, and the molar ratio of nickel to cobalt being 3:1 to 1:3.
[0019] Further, the carrier is ZrO2, γ-Al2O3, SiO2, TiO2, or a composite or a doped body thereof, the active component consisting of nickel and cobalt, and the molar ratio of nickel to cobalt being 1:1. Experimental data have confirmed that the combination of Ni and Co in a molar ratio of 1:1 produces the best synergistic catalytic effect, which is significantly better than other ratios (such as 1:3, 3:1) or single metals, which is a decisive factor for achieving high performance. The nickel-cobalt bimetallic catalyst of the present application is a synergistic system of “Ni-Co-ZrO2” trinity. The key point is not only the bimetallic catalyst, but also the specific combination of the bimetallic catalyst and the ZrO2 carrier. ZrO2 is not only an inert support, but also the surface properties and the possible metal-support strong interaction (SMSI) between the Ni-Co active sites are essential for stabilizing highly dispersed metal particles and promoting CO2 activation, which is the structural basis for achieving high stability and high selectivity.
[0020] Further, the total loading of nickel and cobalt is 1wt%-5wt% of the total mass of the catalyst based on the total mass of metal elements. Too low loading may result in insufficient active sites, and too high loading may result in metal particle agglomeration and reduced dispersion. Optimization within this range can achieve better results than single metal catalysts.
[0021] The composition design of the catalyst of the present application is innovative: Active component: Ni and Co are combined in a molar ratio of 3:1 to 1:3, preferably 1:1. The purpose is to take advantage of the high activity of Ni for hydrocarbon cracking / reforming and the potential advantage of Co for CO generation / desorption, to adjust the electronic structure through possible alloying or interfacial effects, and to achieve synergistic catalysis.
[0022] Carrier selection: the carrier is ZrO2, γ-Al2O3, SiO2, TiO2, or a composite or a doped body thereof, preferably ZrO2, which takes advantage of its good thermal stability, mechanical strength and surface properties (acidity and basicity and oxygen vacancies) to produce strong interaction (SMSI) with active metals, stabilize metal particles and promote CO2 adsorption / activation.
[0023] In terms of structural construction, the present application adopts the “impregnation-drying-calcination-reduction” method to prepare, and constructs a high-activity microstructure by precisely controlling process parameters. The second aspect of the present application provides a preparation method of the above-mentioned bimetallic catalyst, comprising the following steps: S1. Impregnation: Dissolve nickel salt precursor and cobalt salt precursor in deionized water to form an active component solution; disperse the carrier in deionized water to form a suspension; mix the active component solution with the carrier suspension, stir and evaporate to remove water to obtain a solid loaded with precursors; S2. Drying: dry the solid loaded with precursors obtained in step S1; S3. Calcination: grind the dried solid of step S2 and transfer it to a muffle furnace, heat it to 600-800ºC at a heating rate of 10-15ºC / min, and keep it at constant temperature for 2-5 hours; S4. Reduction: grind the solid obtained after calcination of step S3, and transfer it to a tube furnace reactor, heat it to 450ºC-550ºC at a heating rate of 5-15ºC / min from room temperature under a pure hydrogen atmosphere, and keep it at constant temperature for 1.5-4 hours, and then cool it to room temperature to obtain the bimetallic catalyst. The catalyst must be subjected to a hydrogen reduction activation step to ensure that the active components exist in the metallic state (Ni 0 , Co 0 ) rather than the oxidized state. This is a necessary condition for the formation of highly active catalytic centers, especially Ni-Co alloys or interfaces that may exist.
[0024] Further, in step S1, the nickel salt precursor is nickel nitrate or nickel chloride, and the cobalt salt precursor is cobalt nitrate or cobalt chloride; the temperature for evaporating to remove the solvent is 80ºC-90ºC.
[0025] Further, in step S2, the drying temperature is 90ºC-110ºC, and the drying time is 8 hours-16 hours.
[0026] Further, in step S4, the reducing atmosphere is a hydrogen atmosphere or a hydrogen-nitrogen mixed atmosphere, and the hydrogen concentration is 5%-100%, which is intended to ensure that the metal oxides are fully reduced to the active metallic state. The temperature, time and atmosphere (such as 5% H2 / N2) in the hydrogen reduction step are key parameters for forming suitable nanoparticle sizes and alloying degrees, which directly affect the final catalytic activity and stability.
[0027] The third aspect of the present application provides the use of the above-mentioned bimetallic catalyst in the carbon dioxide gasification reforming reaction of waste ion exchange resin.
[0028] Further, the gasification reforming reaction is carried out in a fixed bed reactor, which is divided into a sample section for loading waste ion exchange resin and a catalytic section for loading the bimetallic catalyst, and the reaction process includes: The catalytic section is first preheated to 650-750°C, and after the catalytic section reaches the predetermined temperature, the sample section is heated to 800-1000°C at a temperature increasing rate of 5-20°C / min under a gasification atmosphere containing CO2 to perform the gasification reaction.
[0029] Further, the mass of the bimetallic catalyst is 3%-10% of the mass of the waste ion exchange resin.
[0030] Still further, a two-section fixed bed reactor is used to maximize the performance of the catalyst, and the specific process steps are as follows: 1. Loading: 1 g of the sample of the waste ion exchange resin is placed in the sample section without adding the catalyst, and 0.05 g (5 wt%) of the pre-reduced catalyst is placed in the catalytic section when the catalyst is added.
[0031] 2. Atmosphere replacement: the nitrogen gas path is opened, and purging is performed at a flow rate of 100 ml / min, and after the value of O2 of the gas analyzer is 0, the CO2 flow is adjusted to 10 ml / min and the N2 flow is adjusted to 90 ml / min by using the atmosphere control system to ventilate the experimental system.
[0032] 3. Temperature programming and reaction: the temperature programming is set, wherein the temperature programming of the catalytic section is set to increase the temperature from 0°C to 650-750°C at a temperature increasing rate of 15°C / min, the holding time is 100 min, and the operation is started, and after the temperature of the catalytic section reaches 650-750°C, the sample section is heated from 0°C to 800-1000°C at a temperature increasing rate of 10°C / min, and is held for 30 min, and at this time, the data acquisition software in the computer is opened to collect the experimental results.
[0033] 4. In-situ catalytic reforming (occurring in the catalytic section): the cracking products in the catalytic section undergo the processes of tar cracking, CH4 dry reforming (CH4+ CO2→ 2H2+ 2CO), Boudouard reaction (C + CO2→ 2CO) strengthening, etc., and are finally efficiently converted into high-quality synthesis gas mainly composed of H2 and CO.
[0034] The above application system for maximizing the performance of the catalyst adopts a two-section process logic of "preheating the catalytic section first": the core of the process lies in the space-time separation and temperature field optimization. The catalytic section is first heated to 650-750°C to make it in a high-activity state of "waiting in strict formation", and then the sample cracking products pass through it, realizing the "immediate capture" and "efficient conversion" of unstable intermediates, maximizing the performance of the catalyst, and effectively inhibiting the generation of tar.
[0035] The catalyst is applied to the process designed for its characteristics, and the combination of the two produces a "1+1>2" technical effect.
[0036] Compared with the prior art, the application has the following beneficial effects: 1. Quantitative breakthrough of performance and demonstration of synergistic effect: The application is not a linear improvement of the performance of existing catalysts. Experimental data show that the total synthesis gas yield of the optimal single metal catalyst Ni-ZrO2 is 268.13 mL / g, while the catalyst of the application reaches 308.52 mL / g, with an absolute increase of 40.39 mL / g and a relative increase rate of about 15.1%. This significant increase is not obtained by simple optimization, but by introducing a second metal (Co) and accurately controlling its proportion to 1:1, realizing the "synergistic catalytic effect", which proves the non-obviousness of the technical solution of the application.
[0037] 2. Precise regulation of reaction path and improvement of product value: One of the most prominent advantages of the application is to realize the precise guidance of the reaction path. As shown in the accompanying Figure 1 and the accompanying Figure 4 , the application obtains the highest CO yield (245.86 mL / g) among all the comparison schemes. This shows that the catalyst of the application can selectively and efficiently promote the Boudouard reaction (C + CO2→ 2CO) to convert more solid carbon and CO2 into the target product CO rather than other by-products. This has very high application value for downstream chemical processes (such as carbonyl synthesis, Fischer-Tropsch synthesis adjustment) that require high CO / H2 ratio synthesis gas.
[0038] 3. Significant acceleration of reaction kinetics and improvement of system energy efficiency: From the instantaneous yield curve (Fig. Figure 1 , 2), it can be seen that after using the catalyst of the application, the gas production peak of CO and H2 is more steep, and a higher yield platform can be maintained during the high temperature holding stage. This shows that the catalyst of the application significantly reduces the activation energy of the gasification reaction and accelerates the reaction rate. Faster reaction rate means that gasification can be completed in a shorter processing time, or the same conversion rate can be achieved at a relatively lower temperature, thereby directly reducing energy consumption and improving equipment processing capacity.
[0039] 4. Integrity of technical solution and industrialization potential: The application provides a complete technical solution from "catalyst design-preparation-application". Among them, the two-stage process effectively solves the problems of catalyst deactivation and tar plugging, and the pre-reduction step ensures the immediate activity of the catalyst during start-up, which greatly enhances the potential and reliability of the technology to run stably and efficiently in complex industrial environments. BRIEF DESCRIPTION OF DRAWINGS
[0040] Figure 1 CO instantaneous yield (mL / min) vs. time curve.
[0041] Figure 2 H2 instantaneous yield (mL / min) vs. time curve.
[0042] Figure 3 CH4 instantaneous yield (mL / min) vs. time curve.
[0043] Figure 4 Total gas yield (mL / g) vs. time bar graph. DETAILED DESCRIPTION
[0044] The embodiments of the present application will be described below with reference to preferred embodiments, but the embodiments of the present application are not limited thereto, and can be implemented or applied by other different specific embodiments.
[0045] It should be understood that the preferred embodiments are intended to enable those skilled in the art to understand the present application and to implement it, and are not intended to limit the scope of protection of the present application, and equivalent changes or modifications made in accordance with the spirit and essence of the present application should be included in the scope of protection of the present application.
[0046] The following example bimetallic catalyst includes a support and an active component, the support is a metal oxide or its composite, doped body with high specific surface area and good stability, the active component is composed of nickel and cobalt, and the molar ratio of nickel to cobalt is 3:1 to 1:3.
[0047] I. Example Example 1: Preparation and application of 1Ni / 1Co-ZrO2 bimetallic catalyst The composition design of the catalyst in this example is as follows: Active component: Ni and Co are compounded at a molar ratio of 1:1, and the total loading of nickel and cobalt accounts for 2wt% of the total mass of the catalyst in terms of the total mass of metal elements. The purpose is to take advantage of the high activity of Ni for hydrocarbon cracking / reforming and the potential advantages of Co for CO generation / desorption, to adjust the electronic structure through the alloy or interface effect that may be formed, and to realize synergistic catalysis.
[0048] Support selection: The support in this example is ZrO2. Its good thermal stability, mechanical strength and surface properties (acid-base and oxygen vacancies) are used to produce strong mutual interaction (SMSI) with active metals, stabilize metal particles and promote CO2 adsorption / activation.
[0049] The preparation method of the catalyst in this example is as follows: "dipping-drying-calcination-reduction" method.
[0050] S1. Impregnation: Active metal precursors were weighed according to the calculated results, 0.0405 g of NiCl2-6H2O and 0.0493 g of Co(NO3)2-6H2O were dissolved in 40 ml of deionized water and stirred for 30 minutes. 1 g of ZrO2 was weighed and added to another beaker, 40 ml of deionized water was added and stirred for 10 minutes. The Ni and Co solution was added to the ZrO2 suspension, and stirred at 80°C for about 6 hours until the water was completely evaporated.
[0051] S2. Drying: The resulting solid was placed in a drying oven and dried at 105°C for 12 hours.
[0052] S3. Calcination: The solid was ground and transferred to a muffle furnace, heated to 700°C at a heating rate of 10°C / min, and kept at a constant temperature for 3 hours.
[0053] S4. Reduction: After the resulting solid was ground, it was transferred to a tube furnace reactor, heated to 500°C at a heating rate of 10°C / min under a pure hydrogen atmosphere, and maintained at 500°C for 2 hours, then cooled to room temperature and the final sample was ground to obtain a 1Ni / 1Co-ZrO2 catalyst with a Ni to Co molar ratio of 1:1 and a total loading of 2wt%.
[0054] The application of the 1Ni / 1Co-ZrO2 catalyst prepared in this example in the carbon dioxide gasification reforming reaction of waste ion exchange resin was carried out in a fixed bed reactor, which was divided into a sample section for loading waste ion exchange resin and a catalytic section for loading bimetallic catalyst. The specific process steps are as follows: 1. Charging: 1 g of ion exchange resin sample (waste tire sample) was placed in the sample section without catalyst, and 0.05 g (5 wt%) of pre-reduced catalyst was placed in the catalytic section with catalyst.
[0055] 2. Atmosphere replacement: Open the nitrogen gas path and perform purging at a flow rate of 100 ml / min. After the O2 value of the gas analyzer is 0, use the atmosphere control system to adjust the CO2 flow to 10 ml / min and the N2 flow to 90 ml / min to ventilate the experimental system.
[0056] 3. Temperature programming and reaction: Set the temperature programming, where the temperature programming of the catalytic section is set to increase from 0°C to 700°C at a heating rate of 15°C / min, and the holding time is 100 min. Start running. After the temperature of the catalytic section reaches 700°C, the sample section starts to increase from 0°C to 900°C at a heating rate of 10°C / min, and is kept for 30 min. At this time, open the computer data acquisition software to collect the experimental results.
[0057] 4. In-situ catalytic reforming (happens in catalytic section): The cracking products undergo tar cracking, CH4 dry reforming (CH4+ CO2→ 2H2+ 2CO), Boudouard reaction (C + CO2→ 2CO) intensification, etc. processes in the catalytic section, and are finally converted into high-quality synthesis gas mainly composed of H2 and CO with high efficiency.
[0058] Example 2: Preparation and application of 1Ni / 3Co-ZrO2 bimetallic catalyst The composition design of the catalyst of this example is as follows: Active component: Ni and Co are compounded at a molar ratio of 1:3, and the total loading of nickel and cobalt accounts for 2wt% of the total mass of the catalyst.
[0059] Carrier selection: The carrier of this example is ZrO2.
[0060] The preparation method of the catalyst of this example is as follows: “dipping-drying-calcination-reduction” method. S1. Dipping: According to the calculation results, 0.02025 g of NiCl2·6H2O and 0.07395 g of Co(NO3)2·6H2O are weighed and dissolved in 40 ml of deionized water, and stirred for 30 minutes. 1 g of ZrO2 is weighed and added to another beaker, 40 ml of deionized water is added, and stirred for 10 minutes. The Ni and Co solution is added to the ZrO2 suspension, and stirred at 80ºC for about 6 hours until the water is completely evaporated.
[0061] S2. Drying: The obtained solid is placed in a drying box and dried at 105ºC for 12 hours.
[0062] S3. Calcination: The solid is ground and transferred to a muffle furnace, heated to 700ºC at a heating rate of 10ºC / min, and kept at 700ºC for 3 hours.
[0063] S4. Reduction: After the obtained solid is ground, it is transferred to a tube furnace reactor, heated to 500ºC at a heating rate of 10ºC / min under a pure hydrogen atmosphere, and maintained at 500ºC for 2 hours, then cooled to room temperature and the final sample is ground to obtain a 1Ni / 3Co-ZrO2 catalyst with a molar ratio of Ni to Co of 1:3 and a total loading of 2wt%. The specific process steps are the same as in Example 1.
[0064] Example 3: Preparation and application of 3Ni / 1Co-ZrO2 bimetallic catalyst The composition design of the catalyst of this example is as follows: Active component: Ni and Co were used in a 3:1 molar ratio, the total load of nickel and cobalt was 2wt% of the total mass of the catalyst, based on the total mass of the metal elements.
[0065] Support selection: the support of this example was Zr02.
[0066] Method of preparation of the catalyst of this example: the "impregnation-drying-calcination-reduction" method was used.
[0067] S1. Impregnation: the active metal precursors were weighed according to the calculations, 0.06075 g of NiCl2-6H2O and 0.02465 g of Co(N03)2-6H2O, and dissolved in 40 ml of deionized water, stirring for 30 minutes. 1 g of Zr02was weighed and placed in another beaker, 40 ml of deionized water was added, and stirred for 10 minutes. The Ni and Co solution was added to the Zr02suspension, which was stirred at 80°C for about 6 hours until the water was completely evaporated.
[0068] S2. Drying: the resulting solid was placed in a drying oven at 105°C for 12 hours.
[0069] S3. Calcination: the solid was ground and transferred to a muffle furnace, heated to 700°C at a rate of 10°C / min, and held at that temperature for 3 hours.
[0070] S4. Reduction: the resulting solid was ground and transferred to a tubular furnace reactor, heated to 500°C at a rate of 10°C / min under a pure hydrogen atmosphere, and held at 500°C for 2 hours, then cooled to room temperature and the final sample was ground to obtain a 3Ni / 1Co-Zr02catalyst with a molar ratio of Ni to Co of 3:1 and a total load of 2wt%. The specific process steps are the same as in Example 1.
[0071] Comparative Example 1: gasification reaction without catalyst This comparative example was used to verify the effect of direct CO2gasification of waste ion exchange resin without a catalyst. Application method: the gasification reaction was carried out in a fixed bed reactor, which only had a sample section.
[0072] Process steps were: 1. Charging: 1 g of ion exchange resin sample (waste tire sample) was weighed and placed in the sample section, 2. Atmosphere replacement: the nitrogen gas line was opened and purged at a flow rate of 100 ml / min, and after the gas analyzer value of O2was 0, the CO2flow was adjusted to 10 ml / min and the N2flow was adjusted to 90 ml / min using the atmosphere control system to ventilate the experimental system.
[0073] 3. Temperature programming and reaction: Set the temperature programming, in which the temperature programming of the catalytic section is set to be raised from 0 °C to 700 °C at a temperature rising rate of 15 °C / min, and the holding time is 100 min, and start running. After the temperature of the catalytic section reaches 700 °C, the sample section starts to be raised from 0 °C to 900 °C at a temperature rising rate of 10 °C / min, and is kept for 30 min. At this time, open the data acquisition software in the computer to collect the experimental results.
[0074] Comparative Example 2: Preparation and application of Ni-ZrO2 single metal catalyst The composition design of the catalyst of this example is as follows: Active component: only Ni is used, and the loading of nickel is 2wt% of the total mass of the catalyst in terms of the mass of metal elements.
[0075] Carrier selection: the carrier of this example is ZrO2.
[0076] The preparation method of the catalyst of this comparative example is as follows: the “impregnation-drying-calcination-reduction” method is used.
[0077] S1. Impregnation: according to the calculation result, weigh 0.081 g of active metal precursor NiCl2·6H2O and dissolve it in 40 ml of deionized water, and stir for 30 minutes. Weigh 1 g of ZrO2 and add it to another beaker, add 40 ml of deionized water, and stir for 10 minutes. Add the Ni solution to the ZrO2 suspension, stir at 80ºC for about 6 hours until the water is completely evaporated.
[0078] S2. Drying: put the obtained solid into a drying box and dry at 105ºC for 12 hours.
[0079] S3. Calcination: grind the solid and transfer it to a muffle furnace, heat to 700ºC at a temperature rising rate of 10ºC / min, and keep constant temperature for 3 hours.
[0080] S4. Reduction: after grinding the obtained solid, transfer it to a tube furnace reactor, heat to 500ºC at a temperature rising rate of 10ºC / min under a pure hydrogen atmosphere, and maintain at 500ºC for 2 hours, then cool to room temperature and grind the final sample to obtain a Ni-ZrO2 catalyst with a Ni loading of 2wt%. The specific process steps are the same as in Example 1.
[0081] Comparative Example 3: Preparation and application of Co-ZrO2 single metal catalyst The composition design of the catalyst of this example is as follows: Active component: only Co is used, and the loading of cobalt is 2wt% of the total mass of the catalyst in terms of the mass of metal elements.
[0082] Support selection: The support for this example is ZrO2.
[0083] Preparation of the comparative catalyst: The “impregnation-drying-calcination-reduction” method was used.
[0084] S1. Impregnation: The active metal precursor, 0.0985 g of Co(N03)2-6H20, was weighed according to the calculation and dissolved in 40 ml of deionized water, stirring for 30 minutes. 1 g of Zr02 was weighed and added to another beaker, 40 ml of deionized water was added, and stirred for 10 minutes. The Co solution was added to the Zr02 suspension, and stirred at 80°C for about 6 hours until the water was completely evaporated.
[0085] S2. Drying: The resulting solid was placed in a drying oven and dried at 105°C for 12 hours.
[0086] S3. Calcination: The solid was ground and transferred to a muffle furnace, heated to 700°C at a heating rate of 10°C / min, and held at 700°C for 3 hours.
[0087] S4. Reduction: After the resulting solid was ground, it was transferred to a tube furnace reactor, heated to 500°C at a heating rate of 10°C / min under a pure hydrogen atmosphere, and held at 500°C for 2 hours. The final sample was then ground, resulting in a Co-Zr02 catalyst with a Co loading of 2 wt%. The specific process steps are the same as in Example 1.
[0088] II. Experimental results To verify the effect of the present application, comparative experiments were conducted on the catalysts of Example 1 and Comparative Examples 1-3 above, and the total gas yield data (mL / g) are as follows:
[0089] Result analysis: 1. Highest total yield: The total yield of the syngas of the catalyst of the present application (308.52 mL / g) is about 15.1% higher than that of the optimal single metal catalyst.
[0090] 2. Excellent CO selectivity: The CO yield (245.86 mL / g) is the highest among all catalysts, highlighting its excellent guiding ability for the target reaction path.
[0091] 3. Clear synergistic effect: The best results are obtained with a 1:1 molar ratio of Ni / Co, demonstrating the necessity of the bimetallic design.
[0092] From the attached Figure 1It can be seen that when the sample section temperature rises to 900ºC and is kept at that temperature, the area under the instantaneous CO yield curve using the catalyst of this invention (1Ni / 1Co-ZrO2) is much larger than that without the catalyst, and the peak value is higher, indicating that its CO generation rate is faster and the yield is greater.
[0093] From the appendix Figure 2 It can be seen that the instantaneous yield of H2 using the catalyst of this invention is significantly higher in the later stage of the reaction (high temperature zone) than that without a catalyst, indicating that it can effectively promote the generation of H2.
[0094] From the appendix Figure 3 It can be seen that when using the catalyst of this invention, the instantaneous peak yield of CH4 is comparable to or slightly higher than that without a catalyst, but its decreasing trend at high temperatures may be more pronounced. Combined with the extremely high CO yield, this indicates that the generated CH4 is effectively consumed through the reforming reaction.
[0095] Appendix Figure 4 The bar chart clearly illustrates the data in the table above, listing the yields of CO, H2, and CO+H2 respectively. Different catalysts (none, Ni-ZrO2, Co-ZrO2, 1Ni / 1Co-ZrO2) are plotted on the x-axis, and yield on the y-axis. It can be seen that the bar for the 1Ni / 1Co-ZrO2 catalyst prepared in Example 1 is significantly higher than the other groups, indicating the best total yield of CO+H2.
[0096] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.
Claims
1. A nickel-cobalt bimetallic catalyst for carbon dioxide gasification reforming of spent ion exchange resin, characterized by, The bimetallic catalyst comprises a carrier and an active component, the carrier is a metal oxide or its composite or doped body with high specific surface area and good stability, the active component is composed of nickel and cobalt, and the molar ratio of nickel to cobalt is 3:1 to 1:
3.
2. The bimetallic catalyst of claim 1, wherein, The carrier is ZrO2, γ-Al2O3, SiO2, TiO2, or its composite or doped body, the active component is composed of nickel and cobalt, and the molar ratio of nickel to cobalt is 1:
1.
3. The bimetallic catalyst of claim 1, wherein, The total loading of nickel and cobalt is 1wt%-5wt% of the total mass of the catalyst.
4. A method for producing the bimetallic catalyst as claimed in any one of claims 1 to 3, characterized by, It comprises the following steps: S1. Immersion: dissolve nickel salt precursor and cobalt salt precursor in deionized water to prepare an active component solution; Disperse the carrier in deionized water to form a suspension, mix the active component solution with the carrier suspension, stir and evaporate to remove water to obtain a solid loaded with precursors; S2. Drying: dry the solid loaded with precursors obtained in step S1; S3. Calcination: grind the dried solid of step S2 and transfer it to a muffle furnace, heat it to 600-800ºC at a heating rate of 10-15ºC / min, and keep it at a constant temperature for 2-5 hours; S4. Reduction: grind the solid obtained after calcination in step S3, transfer it to a tube furnace reactor, heat it to 450ºC-550ºC at a heating rate of 5-15ºC / min under a reducing atmosphere, and keep it at a constant temperature for 1.5-4 hours, then cool it to room temperature to obtain the bimetallic catalyst.
5. The preparation method according to claim 4, characterized in that, In step S1, the nickel salt precursor is nickel nitrate or nickel chloride, and the cobalt salt precursor is cobalt nitrate or cobalt chloride; the evaporation temperature to remove the solvent is 80ºC-90ºC.
6. The preparation method according to claim 4, characterized in that, In step S2, the drying temperature is 90ºC-110ºC, and the drying time is 8-16 hours.
7. The preparation method according to claim 4, characterized in that, In step S4, the reducing atmosphere is hydrogen atmosphere or hydrogen-nitrogen mixed atmosphere, and the hydrogen concentration is 5%-100%.
8. Use of the bimetallic catalyst according to any one of claims 1-3 in the carbon dioxide gasification reforming reaction of waste ion exchange resin.
9. Use according to claim 8, characterized in that, The gasification reforming reaction is carried out in a fixed bed reactor, which is divided into a sample section for loading waste ion exchange resin and a catalytic section for loading the bimetallic catalyst, and the reaction process comprises: First, preheat the catalytic section to 650-750ºC, and after the catalytic section reaches the predetermined temperature, place the sample section in a gasification atmosphere containing CO2, heat it to 800-1000ºC at a heating rate of 5-20ºC / min to carry out the gasification reaction.
10. Use according to claim 9, characterized in that, The mass of the bimetallic catalyst is 3%-10% of the mass of the waste ion exchange resin.